Science.gov

Sample records for shellfish geukensia demissa

  1. Seawater and shellfish (Geukensia demissa) quality along the Western Coast of Assateague Island National Seashore, Maryland: an area impacted by feral horses and agricultural runoff.

    PubMed

    Lambert, Mary S; Ozbay, Gulnihal; Richards, Gary P

    2009-08-01

    We evaluated the quality of seawater and ribbed mussels (Gukensia demissa) at six sites along the West Coast of Assateague Island National Seashore (ASIS), a barrier island popular with tourists and fishermen. Parameters evaluated were summertime temperature, pH, salinity, dissolved oxygen, total phosphorus, total ammonia nitrogen, and nitrite levels for seawater and total heterotrophic plate counts and total Vibrionaceae levels for the ribbed mussels. Approximately 150 feral horses (Equus caballus) are located on ASIS and, combined with agricultural runoff from animals and croplands, local wildlife, and anthropogenic inputs, contribute to nutrient loads affecting water and shellfish quality. The average monthly dissolved oxygen for June was 2.65 mg L(-1), below the minimum acceptable threshold of 3.0 mg L(-1). Along Chincoteague Bay, total phosphorus generally exceeded the maximum level of 0.037 mg L(-1), as set by the Maryland Coastal Bays Program management objective for seagrasses, with a high of 1.92 mg L(-1) in June, some 50-fold higher than the recommended threshold. Total ammonia nitrogen approached levels harmful to fish, with a maximum recorded value of 0.093 mg L(-1). Levels of total heterotrophic bacteria spiked to 9.5 x 10(6) cells g(-1) of mussel tissue in August in Sinepuxent Bay, leading to mussels which exceeded acceptable standards for edible bivalves by 19-fold. An average of 76% of the bacterial isolates were in the Vibrionaceae family. Together, these data suggest poor stewardship of our coastal environment and the need for new intervention strategies to reduce chemical and biological contamination of our marine resources. PMID:19132436

  2. Predation of the ribbed mussel geukensia demissa by the blue crab callinectes sapidus

    NASA Astrophysics Data System (ADS)

    Seed, R.

    Callinectes sapidus fed extensively on Geukensia demissa in laboratory aquaria. Several predation techniques used by Callinectes to open its prey are reported. Prey value decreases monotonically with increasing mussel size. Crabs consumed mussels over a wide size range but were generally reluctant to feed on larger mussels whilst smaller, more profitably prey was available. The relative importance of 'energy maximization' and 'time minimization' could not be distinguished. The distribution and population structure of Geukensia at Beaufort, N. Carolina are briefly considered in terms of the foraging strategy of Callinectes.

  3. The introduced ribbed mussel (Geukensia demissa) in Estero de Punta Banda, Mexico: Interactions with the native cord grass, Spartina foliosa

    USGS Publications Warehouse

    Torchin, M.E.; Hechinger, R.F.; Huspeni, T.C.; Whitney, K.L.; Lafferty, K.D.

    2005-01-01

    Introduced populations of Guekensia demissa occur on the west coast of North America. They have been reported in San Francisco Bay, four southern California wetlands, and in Estero de Punta Banda (EPB), Baja California Norte, Mexico. We randomly sampled benthic invertebrates in four habitat types within EPB: marsh, channel, mudflat and pan. Geukensia demissa was the most abundant bivalve in the wetland at EPB. It was significantly associated with the native cordgrass, Spartina foliosa, and occurred at higher average densities in vegetated marsh sites (24/m2) and Spartina-dominated tidal channels (35/m2), compared to mudflat (0/m2), and pan (0/m 2) sites. We estimated that the total biomass of this invader was over four times that of the next most abundant bivalve, Tagelus spp., in EPB. We examined G. demissa for parasites and found that only a few native parasites colonized this introduced host at very low prevalences and intensities. We performed bird surveys to determine the habitat overlap and potential impact of this mussel on the EPB population of light-footed clapper rails (Rallus longirostrus levipes), an endangered species in the United States. The high abundance of G. demissa in EPB, its presence in clapper rail habitat, and its known effects on salt marsh habitat in it's native range, warrant further investigations of the impact of this invader in EPB and elsewhere. ?? Springer 2005.

  4. Particle selection in the ribbed mussel Geukensia demissa and the Eastern oyster Crassostrea virginica: Effect of microalgae growth stage

    NASA Astrophysics Data System (ADS)

    Pales Espinosa, Emmanuelle; Allam, Bassem; Ford, Susan E.

    2008-08-01

    We studied particle selection in the ribbed mussel Geukensia demissa, an important suspension-feeding inhabitant of estuaries and intertidal zones of salt marshes along the Atlantic coast of North America. Adult mussels were fed on several mixtures of microalgal cultures (1) in exponential or (2) in stationary phase of growth, and the proportional occurrence of algal species in pseudofeces was examined by flow cytometry. The Eastern oyster, Crassostrea virginica, was chosen as a reference. Results showed that both mussels and oysters were able to selectively ingest or reject our experimental microalgae. Moreover, the pre-ingestive particle selection was affected by microalgal growth phase, particularly in mussels. For instance, the sorting efficiency index increased significantly in mussels fed with a blend made of Nitzschia closterium, Isochrysis sp. and Tetraselmis suesica harvested in stationary growth phase, as compared to the same blend made with microalgae in exponential growth phase. Isochrysis sp. and T. suesica were preferentially ingested by both bivalves whereas N. closterium, was preferentially rejected in pseudofeces. These results demonstrate particle selection in ribbed mussel and underline the effect of algae growth phase on the sorting mechanisms.

  5. Seston available as a food resource for the ribbed mussel ( Geukensia demissa) in a North American, mid-Atlantic saltmarsh

    NASA Astrophysics Data System (ADS)

    Huang, S.-C.; Kreeger, D. A.; Newell, R. I. E.

    2003-03-01

    We studied the composition of the <25 ?m seston size fraction as a food resource potentially available to suspension feeding ribbed mussels, Geukensia demissa, over an annual cycle in Canary Creek saltmarsh, Delaware Bay. There were significant seasonal variations in the concentration of particulate organic carbon (POC), particulate organic nitrogen (PON), and total carbohydrate, but not cellulose. The concentration of cellulose, measured by hydrolytic cellulase enzyme assay, was relatively low (seasonal range 24 to 35 ?g l -1) and only comprised from 3% of total carbohydrate in May 1996 to 13% in November 1995. We used the biomass of microalgae, estimated from chlorophyll a, and abundance of free-living bacteria and heterotrophic nanoflagellates to calculate each component's equivalent carbon content. Microalgae were the most dominant carbon source (62% annually) among the four identified components (phytoplankton, bacteria, heterotrophic nanoflagellates, and cellulose) in all seasons except in August 1995 when carbon from bacteria was most abundant (55%). The annual average carbon equivalents of heterotrophic nanoflagellates and cellulose were relatively small (2 and 4%, respectively). The total concentration of POC in the seston was much greater than the carbon derived from the four identified components. The proportions that these identified components contributed to POC varied seasonally and combined only accounted for 8-24% of POC. Based on these estimates, the bulk of the POC in Canary Creek marsh was not associated with any of the four components we identified. We suggest that this uncharacterized material was some type of non-lignocellulosic, amorphous detritus of unknown utility as a food resource for ribbed mussels.

  6. Changes in protein expression in the salt marsh mussel Geukensia demissa: evidence for a shift from anaerobic to aerobic metabolism during prolonged aerial exposure

    PubMed Central

    Fields, Peter A.; Eurich, Chris; Gao, William L.; Cela, Bekim

    2014-01-01

    During aerial exposure (emersion), most sessile intertidal invertebrates experience cellular stress caused by hypoxia, and the amount and types of hypoxia-induced stress will differ as exposure time increases, likely leading to altered metabolic responses. We examined proteomic responses to increasing emersion times and decreasing recovery (immersion) times in the mussel Geukensia demissa, which occurs in salt marshes along the east coast of North America. Individuals are found above mean tide level, and can be emersed for over 18 h during spring tides. We acclimated mussels to full immersion at 15°C for 4 weeks, and compared changes in gill protein expression between groups of mussels that were continually immersed (control), were emersed for 6 h and immersed during recovery for 18 h (6E/18R), were emersed for 12 h and recovered for 12 h (12E/12R), or were emersed for 18 h with a 6 h recovery (18E/6R). We found clear differences in protein expression patterns among the treatments. Proteins associated with anaerobic fermentation increased in abundance in 6E/18R but not in 12E/12R or 18E/6R. Increases in oxidative stress proteins were most apparent in 12E/12R, and in 18E/6R changes in cytoskeletal protein expression predominated. We conclude that G. demissa alters its strategy for coping with emersion stress over time, relying on anaerobic metabolism for short- to medium-duration exposure, but switching to an air-gaping strategy for long-term exposure, which reduces hypoxia stress but may cause structural damage to gill tissue. PMID:24501137

  7. Response of Growth and Density of a Population of Geukensia demissa to Land-Derived Nitrogen Loading, in Waquoit Bay, Massachusetts

    NASA Astrophysics Data System (ADS)

    Evgenidou, A.; Valiela, I.

    2002-07-01

    Nutrient enrichment is a widespread phenomenon affecting coastal waters, including salt marshes. As land-derived nitrogen loading in estuarine waters increases, chlorophyll concentrations in the water also increase. We hypothesized that such increases might increase growth of the food-limited population of Geukensia demissa, which is a dominant component of salt marshes. To test this, we conducted a regional scale experiment in three estuaries of Waquoit Bay, Massachusetts that receive different nitrogen loading rates. A stable isotope experiment on mussel tissues and on particulate organic matter (POM) showed that mussels within an estuary fed on POM characteristic of that estuary, demonstrating the direct linkage between POM and mussels within an estuary. In addition, we measured age-specific shell growth rates of mussel populations using two different methods: indirectly, shell growth of mussels indicated by internal shell-lines was measured by fitting the data to the von Bertalanffy equation, and directly, mussels were transplanted from one estuary to the other two, and their actual shell growth rates after 80 days were measured. Growth rates of mussels in the Waquoit Bay estuaries varied with age of the mussel, tidal elevation, and with mean concentration of chlorophyll in the water. Mussels grew best in the lower intertidal zone, at the marsh banks. Young mussels grew faster than older mussels. Growth rates increased in response to presumed greater food supply across the estuaries, only for younger mussels. The significant differences we found among the mussels from different estuaries indicate a response to higher concentrations of food particles available in estuaries subject to higher nitrogen loads.

  8. Chemical and ancillary data associated with bed sediment, young of year Bluefish (Pomatomus saltatrix) tissue, and mussel (Mytilus edulis and Geukensia demissa) tissue collected after Hurricane Sandy in bays and estuaries of New Jersey and New York, 2013–14

    USGS Publications Warehouse

    Smalling, Kelly L.; Deshpande, Ashok D.; Blazer, Vicki; Galbraith, Heather S.; Dockum, Bruce W.; Romanok, Kristin M.; Colella, Kaitlyn; Deetz, Anna C.; Fisher, Irene J.; Imbrigiotta, Thomas E.; Sharack, Beth; Summer, Lisa; Timmons, DeMond; Trainor, John J.; Wieczorek, Daniel; Samson, Jennifer; Reilly, Timothy J.; Focazio, Michael J.

    2015-01-01

    Twenty three PCB congeners, 9 PBDE congeners, and 20 OCPs were detected in composite mussel samples collected throughout the study area. The co-eluting PCB congeners 153 and 132, PBDE 47, 99, and 100, and p,p’-DDE were detected in samples from each site. The highest median concentrations of PCBs and PBDEs were present in mussels from Raritan Bay, N.Y., whereas the highest median concentrations of OCPs were present in mussels from Fire Island Inlet, N.Y., and Shark River, N.J. Mytilus edulis (blue mussels) and Geukensia demissa (ribbed mussels) were thin-sectioned and aged. The blue mussels collected ranged in age from 4 to 13 years, and the ribbed mussels ranged in age from 3 to 12 years.

  9. RELATIONSHIPS AMONG TOTAL LIPID, LIPID CLASSES AND POLYCHLORINATED BIPHENYL CONCENTRATIONS IN TWO INDIGENOUS POPULATIONS OF RIBBED MUSSELS (GUKENSIA DEMISSA) OVER AN ANNUAL CYCLE

    EPA Science Inventory

    Two indigenous ribbed mussel (Geukensia demissa) populations were sampled approximately every four weeks during 1997 to investigate the relationships among concentrations of total lipid, lipid classes, and polychlorinated biphenyls (PCBs). One population was located in a highly c...

  10. Shellfish Allergy

    MedlinePLUS

    ... for Your Child All About Food Allergies Shellfish Allergy KidsHealth > For Parents > Shellfish Allergy Print A A ... Home en español Alergia al marisco About Shellfish Allergy A shellfish allergy is not exactly the same ...

  11. Shellfish Allergy

    MedlinePLUS

    ... Deal With Bullies Pregnant? What to Expect Shellfish Allergy KidsHealth > Parents > Diseases & Conditions > Allergies & the Immune System > ... Cross-Contamination Eating Away From Home About Shellfish Allergy A shellfish allergy is not exactly the same ...

  12. Shellfish Allergy

    MedlinePLUS

    ... also has a fish allergy. Shellfish fall into two different groups: crustaceans (like shrimp, crab, or lobster) and mollusks (like clams, mussels, oysters, scallops, octopus, or squid). Some people with shellfish allergies are ...

  13. Shellfish Allergy

    MedlinePLUS

    ... in a Healthy Relationship? Be Your Best Self Smart Snacking Losing Weight Safely Shellfish Allergy KidsHealth > Teens > Food & Fitness > Problems With Food & Exercise > Shellfish Allergy Print A A A Text Size What's in this article? What Is a Shellfish ...

  14. Amnesic Shellfish Poisoning

    MedlinePLUS

    ... By Syndrome Life Cycle Impacts Human Health Wildlife Ecosystems Socioeconomic Freshwater Regions Distribution - U.S. Distribution - World Maps ... Paralytic Shellfish Poisoning Cyanobacteria Medical Community ... Shellfish Poisoning Causative organisms: Pseudo- ...

  15. Shellfish contamination and spoilage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Molluscan shellfish are prone to contamination by fecal and vibrio bacteria, fecal viruses, biotoxins, and chemical pollutants. In this book chapter, the problems and challenges for the shellfish industry are described and discussed. Basic regulatory frameworks, management strategies, critical cont...

  16. Is shellfish consumption safe?

    PubMed

    Diaz, James H

    2004-01-01

    Louisiana provides nearly 40% of domestic seafood production. America's commercial fisheries, especially coastal shellfish fisheries, now face crippling economic and environmental pressures from seafood imports, over-fishing, urban and agricultural wastewater runoff, harmful algal blooms, and coastal wetlands loss. As a result of these ecosystem stresses, seafood-borne disease now causes 37% of all foodborne illness in the United States. Louisiana and other coastal-state physicians can effectively curtail the rising threat of local shellfish-borne disease outbreaks by supporting responsible coastal restoration and regulation of commercial shell-fishing, especially oyster fishing, and by recommending careful selection and preparation of all shellfish and crustaceans. PMID:15366346

  17. Amnesic shellfish poison.

    PubMed

    Jeffery, B; Barlow, T; Moizer, K; Paul, S; Boyle, C

    2004-04-01

    Amnesic shellfish poisoning (ASP) is caused by consumption of shellfish that have accumulated domoic acid, a neurotoxin produced by some strains of phytoplankton. The neurotoxic properties of domoic acid result in neuronal degeneration and necrosis in specific regions of the hippocampus. A serious outbreak of ASP occurred in Canada in 1987 and involved 150 reported cases, 19 hospitalisations and 4 deaths after consumption of contaminated mussels. Symptoms ranged from gastrointestinal disturbances, to neurotoxic effects such as hallucinations, memory loss and coma. Monitoring programmes are in place in numerous countries worldwide and closures of shellfish harvesting areas occur when domoic acid concentrations exceed regulatory limits. This paper reviews the chemistry, sources, metabolism and toxicology of domoic acid as well as human case reports of ASP and discusses a possible mechanism of toxicity. PMID:15019178

  18. Neurotoxic Shellfish Poisoning

    PubMed Central

    Watkins, Sharon M.; Reich, Andrew; Fleming, Lora E.; Hammond, Roberta

    2008-01-01

    Neurotoxic shellfish poisoning (NSP) is caused by consumption of molluscan shellfish contaminated with brevetoxins primarily produced by the dinoflagellate, Karenia brevis. Blooms of K. brevis, called Florida red tide, occur frequently along the Gulf of Mexico. Many shellfish beds in the US (and other nations) are routinely monitored for presence of K. brevis and other brevetoxin-producing organisms. As a result, few NSP cases are reported annually from the US. However, infrequent larger outbreaks do occur. Cases are usually associated with recreationally-harvested shellfish collected during or post red tide blooms. Brevetoxins are neurotoxins which activate voltage-sensitive sodium channels causing sodium influx and nerve membrane depolarization. No fatalities have been reported, but hospitalizations occur. NSP involves a cluster of gastrointestinal and neurological symptoms: nausea and vomiting, paresthesias of the mouth, lips and tongue as well as distal paresthesias, ataxia, slurred speech and dizziness. Neurological symptoms can progress to partial paralysis; respiratory distress has been recorded. Recent research has implicated new species of harmful algal bloom organisms which produce brevetoxins, identified additional marine species which accumulate brevetoxins, and has provided additional information on the toxicity and analysis of brevetoxins. A review of the known epidemiology and recommendations for improved NSP prevention are presented. PMID:19005578

  19. Paralytic shellfish poisoning.

    PubMed Central

    Acres, J.; Gray, J.

    1978-01-01

    Two cases of paralytic shellfish poisoning after ingestion of mussels occurred in October 1977 in Nova Scotia. The incidence of this type of poisoning is relatively high among persons living on the coast of the Bay of Fundy and the estuary of the St. Lawrence River. The causative organism, Gonyaulax tamarensis, elaborates an endotoxin, saxitoxin, that blocks neuromuscular transmission in the motor axon and muscle membrane while leaving the end-plate unaffected; it also suppresses conduction in the atrioventricular node and inhibits the respiratory centre. The clinical manifestations are unique and include numbness of the lips, tongue and fingertips within minutes of ingestion of the poisoned shellfish, then numbness of the legs, arms and neck, with general muscular incoordination, and finally respiratory distress and muscular paralysis. Treatment is symptomatic and prevention can only occur by public education. Images FIG. 2 FIG. 3 PMID:570450

  20. Dimorphisms and self-incompatibility in the distylous species Palicourea demissa (Rubiaceae): possible implications for its reproductive output.

    PubMed

    Valois-Cuesta, Hamleth; Soriano, Pascual J; Ornelas, Juan Francisco

    2011-01-01

    Distyly has been interpreted as a mechanism that favors cross-fertilization. In this research we describe floral attributes and ancillary floral polymorphisms typically associated to heterostylous plants in Palicourea demissa (Rubiaceae), a distylous shrub of the Venezuelan Andes cloud forests. A hand-pollination experiment was done to evaluate self- and intramorph incompatibility and female reproductive output in both floral morphs. The studied population was morphologically distylous but morph differences in most ancillary floral polymorphisms and reciprocity of the sexual organ heights were found. The floral morphs were self-incompatible and did not differ in fruit set under controlled cross-pollination conditions, but at the population level they exhibited imperfect reciprocal herkogamy. Fruits and seeds of short-styled plants were larger than those of long-styled plants and fruit set was higher in short-styled plants under natural conditions, suggesting a higher reproductive potential among short-styled plants. Given the 1:1 morph ratio within the studied population, further evidence is needed to determine the influence of floral visitors and seed dispersers in the expression of heterostyly in P. demissa under natural conditions. PMID:20577893

  1. Problems associated with shellfish farming.

    PubMed

    Chinabut, S; Somsiri, T; Limsuwan, C; Lewis, S

    2006-08-01

    Shellfish culture is a major sector of aquaculture production worldwide, and zoonoses and drug residues associated with shellfish farm practice are of concern to public health. This paper focuses on three of the most important shellfish species: molluscs, crabs and shrimp. Although many diseases can affect shellfish, they do not appear to be transmittable to humans. Rather, the main hazards are associated with the methods used to farm the different species. The risk to human health from shellfish most commonly relates to contamination by biotoxins produced by marine algae. Another well-recognised problem associated with shellfish culture is the contamination of shellfish with domestic sewage that contains human pathogenic bacteria and viruses, which causes diseases such as typhoid fever and hepatitis. In shrimp farming, the main potential food safety hazards are zoonoses, chemical contamination and veterinary drug residues. Untreated effluent from shrimp farms is a major concern to the environmental sector as it is known to promote plankton blooms if directly discharged into natural water sources. PMID:17094702

  2. Effects of low and high salinity regimes on seasonal gametogenesis of the ribbed mussel Geukensia granosissima in coastal Louisiana, USA

    USGS Publications Warehouse

    Honig, Aaron; LaPeyre, Megan K.; Supan, John

    2014-01-01

    Benthic intertidal bivalves play an essential role in estuarine ecosystems by contributing to habitat provision, water filtration, and host vegetation productivity. As such, ecosystem level changes that impact population distributions and persistence of local bivalve populations may have large ecosystem level consequences, making it important to better understand the population ecology of native bivalves. In order to determine potential impacts of shifting salinity and temperature regimes along the northern Gulf of Mexico, the seasonal timing of gametogenesis in the Gulf estuarine ribbed mussel, Geukensia granossisima, was examined across a salinity gradient in southeastern Louisiana, from July 2011 through October 2012. Ten mussels were randomly sampled monthly from low (~ 5) and high (~25) salinity marsh sites in southeastern Louisiana, and histologically processed to determine the seasonal progression of gametogenesis. Peak ripeness occurred at both sites between April and September, was positively correlated with temperature, and coincided with seasonal shifts in salinity. Mussels located in lower salinity waters demonstrated a shorter period of gametogenesis, and lower rates of ripeness indicating that changes in salinity regimes may impact long-term population dynamics.

  3. The Influence of Feral Horse Activity on Water and Shellfish (Gukensia demissa) Quality Along the Western Coast of Assateague Island National Seashore, Maryland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Feral horses (Equus caballus) inhabit portions of the Western United States and some barrier islands along the East Coast. Approximately 150 feral horses are located on Assateague Island National Seashore (ASIS), Maryland, a barrier island popular with tourists and recreational fishermen. This stu...

  4. Shellfish Allergy: a Comprehensive Review.

    PubMed

    Pedrosa, Mara; Boyano-Martnez, Teresa; Garca-Ara, Carmen; Quirce, Santiago

    2015-10-01

    Shellfish allergy is of increasing concern, as its prevalence has risen in recent years. Many advances have been made in allergen characterization. B cell epitopes in the major allergen tropomyosin have been characterized. In addition to tropomyosin, arginine kinase, sarcoplasmic calcium-binding protein, and myosin light chain have recently been reported in shellfish. All are proteins that play a role in muscular contraction. Additional allergens such as hemocyanin have also been described. The effect of processing methods on these allergens has been studied, revealing thermal stability and resistance to peptic digestion in some cases. Modifications after Maillard reactions have also been addressed, although in some cases with conflicting results. In recent years, new hypoallergenic molecules have been developed, which constitute a new therapeutic approach to allergic disorders. A recombinant hypoallergenic tropomyosin has been developed, which opens a new avenue in the treatment of shellfish allergy. Cross-reactivity with species that are not closely related is common in shellfish-allergic patients, as many of shellfish allergens are widely distributed panallergens in invertebrates. Cross-reactivity with house dust mites is well known, but other species can also be involved in this phenomenon. PMID:24870065

  5. Risk Assessment of Shellfish Toxins

    PubMed Central

    Munday, Rex; Reeve, John

    2013-01-01

    Complex secondary metabolites, some of which are highly toxic to mammals, are produced by many marine organisms. Some of these organisms are important food sources for marine animals and, when ingested, the toxins that they produce may be absorbed and stored in the tissues of the predators, which then become toxic to animals higher up the food chain. This is a particular problem with shellfish, and many cases of poisoning are reported in shellfish consumers each year. At present, there is no practicable means of preventing uptake of the toxins by shellfish or of removing them after harvesting. Assessment of the risk posed by such toxins is therefore required in order to determine levels that are unlikely to cause adverse effects in humans and to permit the establishment of regulatory limits in shellfish for human consumption. In the present review, the basic principles of risk assessment are described, and the progress made toward robust risk assessment of seafood toxins is discussed. While good progress has been made, it is clear that further toxicological studies are required before this goal is fully achieved. PMID:24226039

  6. [Research Progress in Norovirus Bioaccumulation in Shellfish].

    PubMed

    Zhou, Deqing; Su, Laijin; Zhao, Feng; Ma, Liping

    2015-05-01

    Noroviruses (NoVs) are one of the most important foodborne viral pathogens worldwide. Shellfish are the most common carriers of NoVs as they can concentrate and accumulate large amounts of the virus through filter feeding from seawater. Shellfish may selectively accumulate NoVs with different genotypes, and this bioaccumulation may depend on the season and location. Our previous studies found various histo-blood group antigens (HBGAs) in shellfish tissues. While HBGAs might be the main reason that NoVs are accumulated in shellfish, the detailed mechanism behind NoV concentration and bioaccumulation in shellfish is not clear. Here we review current research into NoV bioaccumulation, tissue distribution, seasonal variation, and binding mechanism in shellfish. This paper may provide insight into controlling NoV transmission and decreasing the risks associated with shellfish consumption. PMID:26470540

  7. Viral Depuration by Assaying Individual Shellfish1

    PubMed Central

    Seraichekas, H. R.; Brashear, D. A.; Barnick, J. A.; Carey, P. F.; Liu, O. C.

    1968-01-01

    A study was carried out to further evaluate the practicability of viral depuration by assaying individual shellfish. The Northern quahaug and a strain of the type 1 attenuated poliovirus were used as the working model. Two types of depuration systems were employed: the small experimental tanks and a pilot-size tank with a capacity of approximately 24 bushels (836 liters) of shellfish. Volumes of the individual shellfish samples were found uniform throughout the experiments when a prior selection for the weight of the shellfish was made. There was also no significant difference in volumes of the individual samples during the course of depuration (24 to 96 hr). Under controlled hydrographic conditions, however, the uptake of virus in individual shellfish varied considerably. In general, the individual variability reached 10- to 100-fold. This wide variation would explain the variability of viral contents obtained in pooled samples during depuration as reported previously. During a later phase of depuration, although a great majority of shellfish were free of the virus, a few still harbored minimal amounts of contaminants. The presence of virus in some of the shellfish after various periods of depuration would, theoretically, be obscured by the pooling of the sampled shellfish. Further examination of the negative samples by assaying larger quantities than those routinely used revealed that a few still contained virus. To simulate naturally polluted shellfish as closely as technically possible, shellfish were polluted with minimal amounts of virus. The shellfish were cleansed more rapidly by the depuration process than were those polluted with more virus. Since the naturally polluted shellfish were shown to contain less virus than those studied in the laboratory, it is anticipated that the former type of shellfish may be cleansed more readily by this process within a reasonable period of time. Justification for a field trial of depuration in this country is presented. Images Fig. 1 PMID:4302284

  8. 7 CFR 60.133 - Wild fish and shellfish.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Wild fish and shellfish. 60.133 Section 60.133... FOR FISH AND SHELLFISH General Provisions Definitions § 60.133 Wild fish and shellfish. Wild fish and shellfish means naturally-born or hatchery-originated fish or shellfish released in the wild, and...

  9. 7 CFR 60.133 - Wild fish and shellfish.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Wild fish and shellfish. 60.133 Section 60.133... FOR FISH AND SHELLFISH General Provisions Definitions § 60.133 Wild fish and shellfish. Wild fish and shellfish means naturally-born or hatchery-originated fish or shellfish released in the wild, and...

  10. 7 CFR 60.133 - Wild fish and shellfish.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Wild fish and shellfish. 60.133 Section 60.133... FOR FISH AND SHELLFISH General Provisions Definitions § 60.133 Wild fish and shellfish. Wild fish and shellfish means naturally-born or hatchery-originated fish or shellfish released in the wild, and...

  11. 7 CFR 60.133 - Wild fish and shellfish.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Wild fish and shellfish. 60.133 Section 60.133... FOR FISH AND SHELLFISH General Provisions Definitions § 60.133 Wild fish and shellfish. Wild fish and shellfish means naturally-born or hatchery-originated fish or shellfish released in the wild, and...

  12. Enteric virus and vibrio contamination of shellfish: intervention strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    INTRODUCTION. Molluscan shellfish include oysters, clams, mussels, and cockles, which can cause illnesses from a variety of human pathogens. Enteric viruses, like norovirus and hepatitis A virus, are generally transmitted to shellfish through fecal contamination of shellfish harvesting areas, alth...

  13. 50 CFR 100.28 - Subsistence taking of shellfish.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... following legal types of gear to take shellfish: (i) Abalone iron; (ii) Diving gear; (iii) A grappling hook... shellfish. You may not possess, transport, give, receive, or barter shellfish or their parts taken...

  14. 36 CFR 242.28 - Subsistence taking of shellfish.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... types of gear to take shellfish: (i) Abalone iron; (ii) Diving gear; (iii) A grappling hook; (iv) A... possession of subsistence shellfish. You may not possess, transport, give, receive, or barter shellfish...

  15. 36 CFR 242.28 - Subsistence taking of shellfish.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... types of gear to take shellfish: (i) Abalone iron; (ii) Diving gear; (iii) A grappling hook; (iv) A... possession of subsistence shellfish. You may not possess, transport, give, receive, or barter shellfish...

  16. Diarrhetic Shellfish Poisoning, Washington, USA, 2011

    PubMed Central

    Duchin, Jeffrey S.; Borchert, Jerry; Quintana, Harold Flores; Robertson, Alison

    2013-01-01

    Diarrhetic shellfish poisoning is a gastrointestinal illness caused by consumption of bivalves contaminated with dinophysistoxins. We report an illness cluster in the United States in which toxins were confirmed in shellfish from a commercial harvest area, leading to product recall. Ongoing surveillance is needed to prevent similar illness outbreaks. PMID:23876232

  17. Fish and Shellfish Associated Disease Outbreaks.

    ERIC Educational Resources Information Center

    Levin, M.

    1978-01-01

    Presents a literature review of disease outbreaks related to fish and shellfish, covering publications of 1976-77. This review covers the chemical, bacterial, and viral diseases that are transmitted by fish and shellfish. A list of 50 references is also presented. (HM)

  18. CONTAMINATION OF ATLANTIC COAST COMMERCIAL SHELLFISH

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Shellfish (oysters and/or clams) were obtained from 37 commercial harvesting sites in 12 Atlantic coast states from Maine to Florida and 1 site in New Brunswick, Canada. Gill washings from 25 shellfish at each site were examined by immunofluorescence microscopy (IFA) for oocysts of Cryptosporidium. ...

  19. Detection of enteric viruses in shellfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Norovirus and hepatitis A virus contamination are significant threats to the safety of shellfish and other foods. Methods for the extraction and assay of these viruses from shellfish are complex, time consuming, and technically challenging. Here, we itemize some of the salient points in extracting...

  20. Challenges for Norovirus Detection within Shellfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The GPTT method was developed for rapid extraction of viral RNA that contains a polyA tail from contaminated shellfish to facilitate RT-PCR-based detection methods. This is a four-step method that involves blending shellfish tissue in pH 9.5 glycine buffer, and concentrating the extracted virus by ...

  1. Relevant shellfish consumption data for dietary exposure assessment among high shellfish consumers, Western Brittany, France.

    PubMed

    Picot, Cyndie; Nguyen, Thuan Anh; Carpentier, Franois-Gilles; Roudot, Alain-Claude; Parent-Massin, Dominique

    2011-04-01

    Shellfish consumption can be a major pathway of exposure to pollutants for humans. It is fundamental to know if people eat enough shellfish to cause health problems, firstly in high consumers as recreational shellfish harvesters. The objectives of this study were to investigate the types of shellfish eaten, number of meals, portion size, sources of shellfish and shellfish consumption rates among French recreational shellfish harvesters; to determine factors affecting consumption patterns and to examine the reliability of the two methods used: a Food Frequency Questionnaire and a one-month food diary. The mean consumption rates were 11.63 and 26.21 g/person/day for shellfish derived from a self-harvested source only and from all sources, respectively. Harvester consumption rates were between 6- and 15-fold higher than the general French population. The comparison between the FFQ and the food diary showed that results were reliable. Thereby, our results are relevant to assess risk due to shellfish consumption. PMID:21424967

  2. Red Tide and Paralytic Shellfish Poisoning

    ERIC Educational Resources Information Center

    Dale, Barrie; Yentsch, Clarice M.

    1978-01-01

    Discusses the nature and cause of paralytic shellfish poisoning (PSP). Includes toxic dinoflagellate ecology, taxonomy and life history, and chemistry of the toxins. Recent work with trace metals and directions of future research are also given. (MA)

  3. Not all shellfish "allergy" is allergy!

    PubMed Central

    2011-01-01

    The popularity of shellfish has been increasing worldwide, with a consequent increase in adverse reactions that can be allergic or toxic. The approximate prevalence of shellfish allergy is estimated at 0.5-2.5% of the general population, depending on degree of consumption by age and geographic regions. The manifestations of shellfish allergy vary widely, but it tends to be more severe than most other food allergens. Tropomyosin is the major allergen and is responsible for cross-reactivity between members of the shellfish family, particularly among the crustacea. Newly described allergens and subtle differences in the structures of tropomyosin between different species of shellfish could account for the discrepancy between in vitro cross-antigenicity and clinical cross-allergenicity. The diagnosis requires a thorough medical history supported by skin testing or measurement of specific IgE level, and confirmed by appropriate oral challenge testing unless the reaction was life-threatening. Management of shellfish allergy is basically strict elimination, which in highly allergic subjects may include avoidance of touching or smelling and the availability of self-administered epinephrine. Specific immunotherapy is not currently available and requires the development of safe and effective protocols. PMID:22410209

  4. 50 CFR 100.28 - Subsistence taking of shellfish.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... may use the following legal types of gear to take shellfish: (i) Abalone iron; (ii) Diving gear; (iii... size limits. (g) Unlawful possession of subsistence shellfish. You may not possess, transport,...

  5. 50 CFR 100.28 - Subsistence taking of shellfish.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... may use the following legal types of gear to take shellfish: (i) Abalone iron; (ii) Diving gear; (iii... size limits. (g) Unlawful possession of subsistence shellfish. You may not possess, transport,...

  6. Domoic acid in Portuguese shellfish and fish.

    PubMed

    Vale, P; Sampayo, M A

    2001-06-01

    The presence of domoic acid (DA) in Portuguese shellfish is a recurrent event that affects shellfish resources several times a year, mainly in spring and autumn. Levels of domoic acid as high as twice the regulatory level of 20 microg DA/g tissue are not unusual. When several shellfish species are exploited in the same restricted area, common cockle (Cerastoderma edule) and carpet shell (Venerupis pullastra) are usually amongst the most toxic, followed by peppery furrow shell, clam, mussel, oyster and razor clam. In whole sardine, domoic acid was detected in levels exceeding sometimes the regulatory limit. Fortunately, toxicity is restricted to the gut content, and does not accumulate in muscle tissue. In brain tissue, domoic acid was detected in levels generally below 1 microg/g. Domoic acid was confirmed by spectra acquired with a diode-array detector. The most toxic samples were confirmed by mass spectrometry. PMID:11137551

  7. Infectious diseases associated with molluscan shellfish consumption.

    PubMed Central

    Rippey, S R

    1994-01-01

    A history of shellfish-vectored illnesses (i.e., those associated with consumption of clams, oysters, mussels, and scallops) occurring in the past nine decades is presented. Typhoid fever was a significant public health problem among consumers of raw molluscan shellfish earlier in this century. The development of more effective sewage treatment procedures and the institution of a national program following these outbreaks led to a series of measures which eventually eliminated shellfish-associated typhoid fever. Present-day problems associated with this food source still involve some wastewaterborne bacterial illnesses. However, the principal public health concerns are with wastewater-derived viral pathogens and with bacterial agents of an environmental origin. The nature, occurrence, and magnitude of these public health problems are described. PMID:7834599

  8. Depuration dynamics of viruses in shellfish.

    PubMed

    Muniain-Mujika, I; Girones, R; Tofio-Quesada, G; Calvo, M; Lucena, F

    2002-07-25

    The consumption of shellfish has been associated with viral infections even in cases where shellfish complied with the current regulation, which is based on bacterial analysis. In this study, depuration rates of potential indicators and human viruses have been analysed in order to study the use of complementary parameters for evaluating the microbiological quality of depurated shellfish. Depuration of naturally highly polluted mussels has been evaluated and analyses for Escherichia coli, Clostridium perfringens, somatic coliphages, F-RNA phages and bacteriophages infecting Bacteroides fragilis RYC2056 and HSP40, human adenovirus, enterovirus have been done. Seawater of the depuration tank was disinfected by UV irradiation, ozone and passed through a skimmer and a biological filter. The correct functioning of the depuration tank was monitored by the quantification of total organic carbon (TOC), NH4+ and total aerobic bacteria in the seawater. To study the relation between the bacteriophages and the human viruses analysed, a logistic regression model was applied. F-RNA phages are significantly related to human adenoviruses and enteroviruses. Thus, they can be used as a complementary parameter for evaluating the efficiency of the depuration treatment. Somatic coliphages are also significantly associated with enteroviruses. Bacteriophages infecting B. fragilis HSP40 were analysed by the double-agar-layer (DAL) method, which quantifies infectious viruses, and by nested PCR, which detects the presence of the genome of these phages. The highest sensitivity of the molecular techniques was demonstrated and the results obtained are an indicator of a close relation between positive results by PCR and the presence of infectious viral particles in shellfish. All shellfish samples were negative for human viruses by PCR after 5 days of depuration treatment and the results obtained applying a regression model also showed negative results or nearly for F-RNA phages and bacteriophages infecting B. fragilis RYC2056. Thus, in this specific depuration treatment, 5 days may be necessary to assess the sanitary quality of shellfish. PMID:12076030

  9. 48 CFR 852.270-3 - Purchase of shellfish.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Purchase of shellfish. 852.270-3 Section 852.270-3 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS CLAUSES... Purchase of shellfish. As prescribed in 870.111-3, insert the following clause: Purchase of Shellfish...

  10. 48 CFR 852.270-3 - Purchase of shellfish.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Purchase of shellfish. 852.270-3 Section 852.270-3 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS CLAUSES... Purchase of shellfish. As prescribed in 870.111-3, insert the following clause: Purchase of Shellfish...

  11. A Potential Mechanism of Virus Persistence within Bivalve Shellfish.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The process of enteric virus bioaccumulation by molluscan shellfish has been widely studied and documented. However, it is not understood why some human enteric viruses, which cannot replicate within shellfish, are selectively retained and remain viable within shellfish tissues for extended periods...

  12. Paralytic shellfish poisoning: a case series.

    PubMed

    Hurley, William; Wolterstorff, Cameron; MacDonald, Ryan; Schultz, Debora

    2014-07-01

    We describe a case series of seven patients presenting to an emergency department with symptoms of paralytic shellfish poisoning. They developed varying degrees of nausea, vomiting, diarrhea, weakness, ataxia and paresthesias after eating mussels harvested from a beach near their resort. Four patients were admitted to the hospital, one due to increasing respiratory failure requiring endotracheal intubation and the remainder for respiratory monitoring. All patients made a full recovery, most within 24 hours. The ability to recognize and identify paralytic shellfish poisoning and manage its complications are important to providers of emergency medicine. PMID:25035737

  13. Paralytic Shellfish Poisoning: A Case Series

    PubMed Central

    Hurley, William; Wolterstorff, Cameron; MacDonald, Ryan; Schultz, Debora

    2014-01-01

    We describe a case series of seven patients presenting to an emergency department with symptoms of paralytic shellfish poisoning. They developed varying degrees of nausea, vomiting, diarrhea, weakness, ataxia and paresthesias after eating mussels harvested from a beach near their resort. Four patients were admitted to the hospital, one due to increasing respiratory failure requiring endotracheal intubation and the remainder for respiratory monitoring. All patients made a full recovery, most within 24 hours. The ability to recognize and identify paralytic shellfish poisoning and manage its complications are important to providers of emergency medicine. PMID:25035737

  14. 21 CFR 1240.60 - Molluscan shellfish.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Molluscan shellfish. 1240.60 Section 1240.60 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) REGULATIONS UNDER CERTAIN OTHER ACTS ADMINISTERED BY THE FOOD AND DRUG ADMINISTRATION CONTROL OF COMMUNICABLE DISEASES Specific Administrative...

  15. 21 CFR 1240.60 - Molluscan shellfish.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Molluscan shellfish. 1240.60 Section 1240.60 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...) A person shall not offer for transportation, or transport, in interstate traffic any...

  16. 21 CFR 1240.60 - Molluscan shellfish.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Molluscan shellfish. 1240.60 Section 1240.60 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) REGULATIONS UNDER CERTAIN OTHER ACTS ADMINISTERED BY THE FOOD AND DRUG ADMINISTRATION CONTROL OF COMMUNICABLE DISEASES Specific Administrative...

  17. 21 CFR 1240.60 - Molluscan shellfish.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Molluscan shellfish. 1240.60 Section 1240.60 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...) A person shall not offer for transportation, or transport, in interstate traffic any...

  18. 21 CFR 1240.60 - Molluscan shellfish.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Molluscan shellfish. 1240.60 Section 1240.60 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...) A person shall not offer for transportation, or transport, in interstate traffic any...

  19. BARATARIA/TERREBONNE SHELLFISH CHALLENGE INITATIVE

    EPA Science Inventory

    This project provides the resources to the Barataria/Terrebonne National Estuary Program to work toward implementation of projects in the four general categories below that will allow the opening of closed shellfish growing waters to harvest. v Connecting poorly operating se...

  20. THE EVOLUTION OF MOLLUSCAN SHELLFISH SAFETY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Molluscan shellfish represent one of the few animals frequently eaten raw or only lightly cooked. Since they are filter feeders, able to concentrate contaminants from the water within their edible tissues, they have been widely associated with outbreaks of illness. Heavy metals, petroleum hydrocar...

  1. Species and series boundaries of Solanum series Longipedicellata (Solanaceae) and phenetically similar species in ser. Demissa and ser. Tuberosa: implications for a practical taxonomy of Section Petota.

    PubMed

    Spooner, David M.; Van Den Berg, Ronald G.; Miller, Joseph T.

    2000-12-01

    Species boundaries were assessed by phenetic analyses of morphological data for all species of wild potatoes (SOLANUM: section PETOTA:) assigned to ser. LONGIPEDICELLATA: S. fendleri, S. hjertingii, S. matehualae, S. papita, S. polytrichon, and S. stoloniferum. These six tetraploid species grow in the southeastern United States (S. fendleri) and Mexico (all six species). We also analyzed morphologically similar species in ser. DEMISSA: (S. demissum) and ser. TUBEROSA: (S. avilesii, S. gourlayi, S. verrucosum). We chose S. verrucosum and S. demissum as Mexican representatives, and S. avilesii and S. gourlayi as South American representatives of other series that are difficult to distinguish from ser. LONGIPEDICELLATA: We also analyzed morphologically more dissimilar species in ser. TUBEROSA: (S. berthaultii) and ser. YUNGASENSIA: (S. chacoense). The results support only three species in ser. LONGIPEDICELLATA: (1) S. polytrichon, (2) S. hjertingii + S. matehualae, (3) S. fendleri + S. papita + S. stoloniferum. Solanum avilesii, S. gourlayi, and to a lesser extent S. demissum and S. verrucosum are very similar to members of ser. LONGIPEDICELLATA: and are difficult to distinguish practically from them, despite differences in chromosome numbers and crossability relationships. These data help document and explain the extensive taxonomic difficulty in sect. Petota, highlight conflicts between biological and morphological species concepts, and add to a growing body of evidence that too many wild potato species are recognized. PMID:11159132

  2. Determination of paralytic shellfish toxins in Portuguese shellfish by automated pre-column oxidation.

    PubMed

    Vale, P; de M Sampayo, M A

    2001-04-01

    Automated pre-column oxidation (the method of Lawrence) was implemented on a routine basis since the end of 1996 to study paralytic shellfish poisoning (PSP) toxins in Portuguese shellfish. Liquid chromatography confirmed the presence of PSP toxins when the known toxic algae were present: Gymnodinium catenatum and/or Alexandrium cf. lusitanicum. On the other side, it has eliminated PSP toxins as a possible recurrent contaminant in oysters from Sado estuary. These oysters were already known to contain high levels of some metals (mainly zinc, copper and cadmium) due to their location in a contaminated area and their particular physiology prone to accumulate metals. The presence of PSP toxins in Scrobicularia plana from Mondego estuary and Tellina crassa from the northern coast, during the absence of the above toxic microalgae in the water column, was confirmed. Unlike other shellfish, these two genera have the feeding habit of aspirating more sediment than organisms in suspension, and probably ingest from the sediment resting cysts of PSP producing microalgae. This is another route of contamination that may help to explain why after a bloom certain shellfish species maintain toxicity for long periods. The method revealed to have a fast implementation on a daily basis, short analysis time (around 20 min between samples), high sensitivity and robustness, and therefore, it is one of the best HPLC methods for screening a large number of shellfish samples for monitoring purposes. PMID:11024496

  3. Cytotoxicity and mycotoxin production of shellfish-derived Penicillium spp., a risk for shellfish consumers.

    PubMed

    Geiger, M; Guitton, Y; Vansteelandt, M; Kerzaon, I; Blanchet, E; Robiou du Pont, T; Frisvad, J C; Hess, P; Pouchus, Y F; Grovel, O

    2013-11-01

    In order to assess the putative toxigenic risk associated with the presence of fungal strains in shellfish-farming areas, Penicillium strains were isolated from bivalve molluscs and from the surrounding environment, and the influence of the sample origin on the cytotoxicity of the extracts was evaluated. Extracts obtained from shellfish-derived Penicillia exhibited higher cytotoxicity than the others. Ten of these strains were grown on various media including a medium based on mussel extract (Mytilus edulis), mussel flesh-based medium (MES), to study the influence of the mussel flesh on the production of cytotoxic compounds. The MES host-derived medium was created substituting the yeast extract of YES medium by an aqueous extract of mussel tissues, with other constituent identical to YES medium. When shellfish-derived strains of fungi were grown on MES medium, extracts were found to be more cytotoxic than on the YES medium for some of the strains. HPLC-UV/DAD-MS/MS dereplication of extracts from Penicillium marinum and P. restrictum strains grown on MES medium showed the enhancement of the production of some cytotoxic compounds. The mycotoxin patulin was detected in some P. antarcticum extracts, and its presence seemed to be related to their cytotoxicity. Thus, the enhancement of the toxicity of extracts obtained from shellfish-derived Penicillium strains grown on a host-derived medium, and the production of metabolites such as patulin suggests that a survey of mycotoxins in edible shellfish should be considered. PMID:24006923

  4. Validation Study for Analytical Method of Diarrhetic Shellfish Poisons in 9 Kinds of Shellfish.

    PubMed

    Yamaguchi, Mizuka; Yamaguchi, Takahiro; Kakimoto, Kensaku; Nagayoshi, Haruna; Okihashi, Masahiro; Kajimura, Keiji

    2016-01-01

    A method was developed for the simultaneous determination of okadaic acid, dinophysistoxin-1 and dinophysistoxin-2 in shellfish using ultra performance liquid chromatography with tandem mass spectrometry. Shellfish poisons in spiked samples were extracted with methanol and 90% methanol, and were hydrolyzed with 2.5 mol/L sodium hydroxide solution. Purification was done on an HLB solid-phase extraction column. This method was validated in accordance with the notification of Ministry of Health, Labour and Welfare of Japan. As a result of the validation study in nine kinds of shellfish, the trueness, repeatability and within-laboratory reproducibility were 79-101%, less than 12 and 16%, respectively. The trueness and precision met the target values of notification. PMID:26936305

  5. Shellfish toxicity: human health implications of marine algal toxins.

    PubMed

    James, K J; Carey, B; O'Halloran, J; van Pelt, F N A M; Skrabkov, Z

    2010-07-01

    Five major human toxic syndromes caused by the consumption of shellfish contaminated by algal toxins are presented. The increased risks to humans of shellfish toxicity from the prevalence of harmful algal blooms (HABs) may be a consequence of large-scale ecological changes from anthropogenic activities, especially increased eutrophication, marine transport and aquaculture, and global climate change. Improvements in toxin detection methods and increased toxin surveillance programmes are positive developments in limiting human exposure to shellfish toxins. PMID:20412612

  6. Shellfish and House Dust Mite Allergies: Is the Link Tropomyosin?

    PubMed Central

    Wong, Lydia; Huang, Chiung Hui

    2016-01-01

    Crustacean shellfish allergy is an important cause of food allergy and anaphylaxis in Asia. The major allergen in shellfish allergy is tropomyosin, a pan-allergen that is also found in house dust mites and cockroaches. Tropomyosins from house dust mites (HDMs) have a high sequence homology to shellfish tropomyosins, and cross-reactivity between HDM and shrimp tropomyosins has been demonstrated. Exposure to inhaled tropomyosins from house dust mites has been postulated to be the primary sensitizer for shellfish allergy, in a reaction analogous to the oral allergy (inhalant-food) syndrome. This notion is supported by indirect data from the effects of HDM immunotherapy on shellfish allergy, and strong correlations of shellfish and HDM sensitization. HDM immunotherapy has been reported to induce both shrimp allergy in non-allergic patients and shrimp tolerance in shrimp-allergic patients. Epidemiological surveys have also demonstrated a strong correlation between shellfish and HDM sensitization in both hospital-based and community-based studies. Unexposed populations have also been shown to develop sensitization-shellfish sensitization in orthodox Jews with no history of shellfish consumption was associated with HDM sensitization. Reciprocally, HDM sensitization in an Icelandic population living in a HDM-free environment was associated with shrimp sensitization. In vitro IgE inhibition studies on sera in shrimp-allergic Spanish patients indicate that mites are the primary sensitizer in shrimp-allergic patients living in humid and warm climates. Current data supports the hypothesis that tropomyosin is the link between HDM and shellfish allergies. The role of tropomyosin in HDM and shellfish allergies is a fertile field for investigation as it may provide novel immunotherapeutic strategies for shellfish allergy. PMID:26739402

  7. Shellfish and House Dust Mite Allergies: Is the Link Tropomyosin?

    PubMed

    Wong, Lydia; Huang, Chiung Hui; Lee, Bee Wah

    2016-03-01

    Crustacean shellfish allergy is an important cause of food allergy and anaphylaxis in Asia. The major allergen in shellfish allergy is tropomyosin, a pan-allergen that is also found in house dust mites and cockroaches. Tropomyosins from house dust mites (HDMs) have a high sequence homology to shellfish tropomyosins, and cross-reactivity between HDM and shrimp tropomyosins has been demonstrated. Exposure to inhaled tropomyosins from house dust mites has been postulated to be the primary sensitizer for shellfish allergy, in a reaction analogous to the oral allergy (inhalant-food) syndrome. This notion is supported by indirect data from the effects of HDM immunotherapy on shellfish allergy, and strong correlations of shellfish and HDM sensitization. HDM immunotherapy has been reported to induce both shrimp allergy in non-allergic patients and shrimp tolerance in shrimp-allergic patients. Epidemiological surveys have also demonstrated a strong correlation between shellfish and HDM sensitization in both hospital-based and community-based studies. Unexposed populations have also been shown to develop sensitization-shellfish sensitization in orthodox Jews with no history of shellfish consumption was associated with HDM sensitization. Reciprocally, HDM sensitization in an Icelandic population living in a HDM-free environment was associated with shrimp sensitization. In vitro IgE inhibition studies on sera in shrimp-allergic Spanish patients indicate that mites are the primary sensitizer in shrimp-allergic patients living in humid and warm climates. Current data supports the hypothesis that tropomyosin is the link between HDM and shellfish allergies. The role of tropomyosin in HDM and shellfish allergies is a fertile field for investigation as it may provide novel immunotherapeutic strategies for shellfish allergy. PMID:26739402

  8. Complete genome sequence for the shellfish pathogen Vibrio coralliilyticus RE98 isolated from a shellfish hatchery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vibrio coralliilyticus is a pathogen of corals and larval shellfish. Publications on strain RE98 list it as a Vibrio tubiashii; however, whole genome sequencing confirms RE98 as V. coralliilyticus containing a total of 6,037,824 bp consisting of two chromosomes (3,420,228 and 1,917,482 bp), and two...

  9. [Petroleum hydrocarbon pollution status in shellfish culture area of Sanggou Bay and effect on quality safety of shellfish].

    PubMed

    Qiao, Xiang-Ying; Chen, Bi-Juan; Zhou, Ming-Ying; Cui, Zheng-Guo

    2011-08-01

    Petroleum hydrocarbon concentrations in seawater, surface sediments and culture shellfish were investigated in shellfish culture area of Sanggou Bay from Jan. to Nov. in 2008. Investigation was conducted on the distribution and variation of petroleum hydrocarbon concentrations in seawater and sediments in the shellfish culture area of Sanggou Bay, as well as on the levels and the differences in petroleum hydrocarbon concentrations among the shellfish species. In addition, the petroleum hydrocarbon pollution status in the three media was evaluated and the effects of accumulated petroleum hydrocarbon in shellfish on the food safety risk were discussed. The results indicated: 1) Petroleum hydrocarbon concentrations in seawater in the shellfish culture area of Sanggou Bay were in the range of 3.61 - 98.21 microg/L; the mean values of petroleum hydrocarbon concentrations in sediments were in the range of 6.75-25.95 mg/kg; petroleum hydrocarbon concentrations in culture shellfish were in the range of 2.14- 42.87 mg/kg; and petroleum hydrocarbon concentrations in shellfish varied largely among different species, with the mean values in the sequence of clam Venerupis variegata > oyster > scallop; 2) Monthly petroleum hydrocarbon concentrations in seawater and surface sediments varied significantly in Sanggou Bay shellfish culture area, with the highest and the lowest values of petroleum hydrocarbon concentrations in seawater that occurred in July and in August, respectively, and with the highest and the lowest values of petroleum hydrocarbon concentrations in surface sediments that occurred in September and in March, respectively; 3) According to the corresponding evaluation criteria, the petroleum hydrocarbon pollution status in surface sediments in Sanggou Bay shellfish culture area was unpolluted but the status in surface seawater was polluted. The culture shellfish was also polluted by petroleum hydrocarbon with different degrees among three species, namely, the pollution degree of clam Venerupis variegata and oyster was more serious than that of scallop Chlamys farreri; 4) The results of linear regression analysis showed that petroleum hydrocarbon concentrations in shellfish had a significantly positive correlation with the concentrations in seawater, while the linear correlation between the concentrations in shellfish and surface sediments was not obvious; and 5) According to the pollution level of petroleum hydrocarbon in shellfish, the food safety risk of three culture shellfishes in Sanggou Bay was relatively low. PMID:22619968

  10. New targets for expedient detection of viruses within shellfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previously our laboratory developed an expedient method for extraction of viral RNA from food-borne virus contaminated bivalve shellfish, termed the GPTT protocol. This protocol utilizes either whole shellfish or dissected digestive diverticula. This four step protocol utilizes a high pH glycine or...

  11. 36 CFR 242.28 - Subsistence taking of shellfish.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Subsistence taking of shellfish. 242.28 Section 242.28 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE SUBSISTENCE MANAGEMENT REGULATIONS FOR PUBLIC LANDS IN ALASKA Subsistence Taking of Fish and Wildlife § 242.28 Subsistence taking of shellfish....

  12. Shellfish Toxins Targeting Voltage-Gated Sodium Channels

    PubMed Central

    Zhang, Fan; Xu, Xunxun; Li, Tingting; Liu, Zhonghua

    2013-01-01

    Voltage-gated sodium channels (VGSCs) play a central role in the generation and propagation of action potentials in excitable neurons and other cells and are targeted by commonly used local anesthetics, antiarrhythmics, and anticonvulsants. They are also common targets of neurotoxins including shellfish toxins. Shellfish toxins are a variety of toxic secondary metabolites produced by prokaryotic cyanobacteria and eukaryotic dinoflagellates in both marine and fresh water systems, which can accumulate in marine animals via the food chain. Consumption of shellfish toxin-contaminated seafood may result in potentially fatal human shellfish poisoning. This article provides an overview of the structure, bioactivity, and pharmacology of shellfish toxins that act on VGSCs, along with a brief discussion on their pharmaceutical potential for pain management. PMID:24287955

  13. Environmental transmission of human noroviruses in shellfish waters.

    PubMed

    Campos, Carlos J A; Lees, David N

    2014-06-01

    Human noroviruses (NoV) are the most common cause of epidemic gastroenteritis following consumption of bivalve shellfish contaminated with fecal matter. NoV levels can be effectively reduced by some sewage treatment processes such as activated sludge and membrane bioreactors. However, tertiary sewage treatment and substantial sewage dilution are usually required to achieve low concentrations of virus in shellfish. Most outbreaks have been associated with shellfish harvested from waters affected by untreated sewage from, for example, storm overflows or overboard disposal of feces from boats. In coastal waters, NoV can remain in suspension or associate with organic and inorganic matter and be accumulated by shellfish. Shellfish take considerably longer to purge NoV than fecal indicator bacteria when transferred from sewage-polluted estuarine waters to uncontaminated waters. The abundance and distribution of NoV in shellfish waters are influenced by the levels of sewage treatment, proximity of shellfish beds to sewage sources, rainfall, river flows, salinity, and water temperature. Detailed site-specific information on these factors is required to design measures to control the viral risk. PMID:24705321

  14. Environmental Transmission of Human Noroviruses in Shellfish Waters

    PubMed Central

    Lees, David N.

    2014-01-01

    Human noroviruses (NoV) are the most common cause of epidemic gastroenteritis following consumption of bivalve shellfish contaminated with fecal matter. NoV levels can be effectively reduced by some sewage treatment processes such as activated sludge and membrane bioreactors. However, tertiary sewage treatment and substantial sewage dilution are usually required to achieve low concentrations of virus in shellfish. Most outbreaks have been associated with shellfish harvested from waters affected by untreated sewage from, for example, storm overflows or overboard disposal of feces from boats. In coastal waters, NoV can remain in suspension or associate with organic and inorganic matter and be accumulated by shellfish. Shellfish take considerably longer to purge NoV than fecal indicator bacteria when transferred from sewage-polluted estuarine waters to uncontaminated waters. The abundance and distribution of NoV in shellfish waters are influenced by the levels of sewage treatment, proximity of shellfish beds to sewage sources, rainfall, river flows, salinity, and water temperature. Detailed site-specific information on these factors is required to design measures to control the viral risk. PMID:24705321

  15. Advances in monitoring and toxicity assessment of brevetoxins in molluscan shellfish.

    PubMed

    Plakas, Steven M; Dickey, Robert W

    2010-08-15

    Herein, we describe advancements in monitoring of brevetoxins in molluscan shellfish, with respect to exposure management and control of neurotoxic shellfish poisoning (NSP). Current knowledge of the fate of brevetoxins in molluscan shellfish, and the toxic potency of brevetoxin metabolites, is presented. We review rapid assays for measuring composite brevetoxins, and methodology for measuring constituent brevetoxins, in contaminated shellfish. The applicability of in vitro methods for estimating brevetoxin burden and composite toxicity in shellfish is assessed. Specific and measurable biomarkers of brevetoxin exposure and toxicity in shellfish, and of human intoxication, are described. Their utility in regulatory monitoring of toxic shellfish and in clinical diagnosis of NSP is evaluated. PMID:19925816

  16. Determination of paralytic shellfish toxins in shellfish by receptor binding assay: collaborative study.

    PubMed

    Van Dolah, Frances M; Fire, Spencer E; Leighfield, Tod A; Mikulski, Christina M; Doucette, Gregory J

    2012-01-01

    A collaborative study was conducted on a microplate format receptor binding assay (RBA) for paralytic e shellfish toxins (PST). The assay quantifies the composite PST toxicity in shellfish samples based on the ability of sample extracts to compete with (3)H saxitoxin (STX) diHCl for binding to voltage-gated sodium channels in a rat brain membrane preparation. Quantification of binding can be carried out using either a microplate or traditional scintillation counter; both end points were included in this study. Nine laboratories from six countries completed the study. One laboratory analyzed the samples using the precolumn oxidation HPLC method (AOAC Method 2005.06) to determine the STX congener composition. Three laboratories performed the mouse bioassay (AOAC Method 959.08). The study focused on the ability of the assay to measure the PST toxicity of samples below, near, or slightly above the regulatory limit of 800 (microg STX diHCl equiv./kg). A total of 21 shellfish homogenates were extracted in 0.1 M HCl, and the extracts were analyzed by RBA in three assays on separate days. Samples included naturally contaminated shellfish samples of different species collected from several geographic regions, which contained varying STX congener profiles due to their exposure to different PST-producing dinoflagellate species or differences in toxin metabolism: blue mussel (Mytilus edulis) from the U.S. east and west coasts, California mussel (Mytilus californianus) from the U.S. west coast, chorito mussel (Mytilus chiliensis) from Chile, green mussel (Perna canaliculus) from New Zealand, Atlantic surf clam (Spisula solidissima) from the U.S. east coast, butter clam (Saxidomus gigantea) from the west coast of the United States, almeja clam (Venus antiqua) from Chile, and Atlantic sea scallop (Plactopecten magellanicus) from the U.S. east coast. All samples were provided as whole animal homogenates, except Atlantic sea scallop and green mussel, from which only the hepatopancreas was homogenized. Among the naturally contaminated samples, five were blind duplicates used for calculation of RSDr. The interlaboratory RSDR of the assay for 21 samples tested in nine laboratories was 33.1%, yielding a HorRat value of 2.0. Removal of results for one laboratory that reported systematically low values resulted in an average RSDR of 28.7% and average HorRat value of 1.8. Intralaboratory RSDr based on five blind duplicate samples tested in separate assays, was 25.1%. RSDr obtained by individual laboratories ranged from 11.8 to 34.9%. Laboratories that are routine users of the assay performed better than nonroutine users, with an average RSDr of 17.1%. Recovery of STX from spiked shellfish homogenates was 88.1-93.3%. Correlation with the mouse bioassay yielded a slope of 1.64 and correlation coefficient (r(2)) of 0.84, while correlation with the precolumn oxidation HPLC method yielded a slope of 1.20 and an r(2) of 0.92. When samples were sorted according to increasing toxin concentration (microg STX diHCl equiv./kg) as assessed by the mouse bioassay, the RBA returned no false negatives relative to the 800 microg STX diHCl equiv./kg regulatory limit for shellfish. Currently, no validated methods other than the mouse bioassay directly measure a composite toxic potency for PST in shellfish. The results of this interlaboratory study demonstrate that the RBA is suitable for the routine determination of PST in shellfish in appropriately equipped laboratories. PMID:22816272

  17. Contamination of Atlantic coast commercial shellfish with Cryptosporidium.

    PubMed

    Fayer, R; Trout, J M; Lewis, E J; Santin, M; Zhou, L; Lal, A A; Xiao, L

    2003-01-01

    Shellfish (oysters and/or clams) were obtained from 37 commercial harvesting sites in 13 Atlantic coast states from Maine to Florida and one site in New Brunswick, Canada. Gill washings from each of 25 shellfish at each site were examined by immunofluorescence microscopy (IFA) for oocysts of Cryptosporidium. Gill washings from another 25 shellfish at each site were grouped into five pools of five shellfish each. DNA from each pool was utilized for PCR and genotyping. Oocysts were found in 3.7% of 925 oysters and clams examined by IFA in shellfish from New Brunswick and 11 of 13 states. Cryptosporidium DNA was detected by PCR in 35.2% of 185 pools. Cryptosporidium parvum genotypes 1 and 2, and Cryptosporidium meleagridis,all of which have been identified in infected humans, were identified at 37.8% of the sites. Gill washings from every site were tested for the presence of infectious oocysts by biological assay in neonatal BALB/c mice but no mice were found infected, suggesting that either the oocysts were no longer infectious or infections in mice were below the level of detection. Collectively, these findings indicate that Cryptosporidium species, indicative of pollution from human and animal feces and potentially infectious for humans, were found in commercial shellfish from 64.9% of sites examined along the Atlantic coast by either microscopy or molecular testing. Previous reports link periods of high rainfall with the elevated numbers of pathogen contaminated shellfish. Because shellfish in the present study were examined during a period of exceptionally low precipitation, the data are thought to underestimate the number of Cryptosporidium contaminated shellfish likely to be found during periods of normal or above normal precipitation. PMID:12489014

  18. Should I Be Concerned about Eating Fish and Shellfish?

    MedlinePLUS

    ... children and the elderly are at a greater health risk than others. Additionally, some individuals are at a ... academic community. ISSC Exit - provides information on the health risks from eating pathogen-contaminated shellfish. Women Children Elderly ...

  19. Expanding shellfish aquaculture: A review of the ecological services provided by and impacts of native and cultured bivalves in shellfish dominated ecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aquaculture is making an increasing contribution to world-wide demand for bivalve shellfish at the same time that substantial efforts are being made to restore wild shellfish populations because they are declining. Impacts of shellfish culture to natural systems have been evaluated, but both native...

  20. Surveillance of Hepatitis E Virus Contamination in Shellfish in China

    PubMed Central

    Gao, Shenyang; Li, Dandan; Zha, Enhui; Zhou, Tiezhong; Wang, Shen; Yue, Xiqing

    2015-01-01

    Background: Hepatitis E virus (HEV) has been confirmed to be a zoonotic virus of worldwide distribution. HEV contamination in the water environment has not been well examined in China. The objective of this study was to evaluate HEV contamination in shellfish in a coastal area of China. Such contamination would be significant for evaluating public health risks. Methods: samples of three species shellfish were collected from thirteen points of estuarine tidal flats around the Bohai Gulf and screened for HEV RNA using an in-house nested RT-PCR assay. The detected HEV-positive samples were further verified by gene cloning and sequencing analysis. Results: the overall HEV-positive detection rate is approximately 17.5% per kilogram of shellfish. HEV was more common among S. subcrenata (28.2%), followed by A. granosa (14.3%) and R. philippinarum (11.5%). The phylogenetic analysis of the 13 HEV strains detected revealed that gene fragments fell into two known 4 sub-genotypes (4b/4d) groups and another unknown group. Conclusions: 13 different sub-genotype 4 HEVs were found in contaminated shellfish in the Bohai Gulf rim. The findings suggest that a health risk may exist for users of waters in the Bonhai area and to consumers of shellfish. Further research is needed to assess the sources and infectivity of HEV in these settings, and to evaluate additional shellfish harvesting areas. PMID:25689991

  1. Comparative analysis of viral pathogens and potential indicators in shellfish.

    PubMed

    Muniain-Mujika, I; Calvo, M; Lucena, F; Girones, R

    2003-05-25

    Shellfish can be responsible of outbreaks of infectious diseases and current health measures do not guarantee the absence of viral pathogens in this product. Here we examine the presence of pathogenic viruses and potential indicators in shellfish in a comparative analysis.Sixty shellfish samples collected in three areas with different levels of faecal contamination were analysed for Escherichia coli, total coliforms, Clostridium perfringens, somatic coliphages, F-specific phages of RNA (F-RNA), bacteriophages infecting Bacteroides fragilis RYC2056, human adenovirus, enterovirus and hepatitis A virus (HAV). Viruses were eluted in a glycine buffer at pH 10. The overall percentage of viral pathogens detected was 47% for human adenoviruses, 19% for enteroviruses and 24% for HAV. Since all the samples positive for enterovirus and HAV were also positives for human adenovirus, the latter may be considered useful as a molecular index of viral contamination in shellfish. No significant differences in the bioaccumulation of bacteria and bacteriophages for oysters or mussels were observed. It was found that the probability of detection of any of the pathogenic virus decreases as the temperature of shellfish growing waters increases. However, the probability of detecting viruses increases when phages of B. fragilis are found. Although more data are needed in order to fulfil the need of viral indicators for controlling the presence of human viruses in shellfish, the obtained results indicate that phages infecting B. fragilis RYC2056 could be a suitable group of bacteriophages to be used as an indicator of the presence of viruses in shellfish. PMID:12672594

  2. Profiles of paralytic shellfish poisoning toxins in shellfish from Portugal explained by carbamoylase activity.

    PubMed

    Artigas, Mireia Lara; Vale, Paulo Joo Vieira; Gomes, Susana Sousa; Botelho, Maria Joo; Rodrigues, Susana Margarida; Amorim, Ana

    2007-08-10

    The presence of paralytic shellfish poisoning (PSP) toxins has not been recorded in the Portuguese coast since 1995. A bloom of Gymnodinium catenatum occurred in the NW coast of Portugal in the autumn of 2005, and PSP profiles were determined in several inshore and offshore shellfish species by HPLC after pre-column oxidation. Most of the species studied contained a complex toxin profile, typically representative of contamination by G. catenatum. However, clams such as Spisula solida contained mainly decarbamoyl toxins, while less extensive transformation was found in Scrobicularia plana. In vitro incubation of S. solida digestive glands with PSP standards revealed a rapid transformation of carbamate and N-sulfocarbamoyl toxins into their corresponding decarbamate analogues. After 24 h, less than 5% of the carbamate or N-sulfocarbamoyl toxins tested remained. After a 24 h in vitro incubation of S. plana digestive glands, no decarbamate analogues were detected. Artificial toxification of S. plana with cultures of G. catenatum revealed the conversion into decarbamoyl analogues progressed slowly: initially dcGTX2+3 and dcSTX accounted only for 5% of total non N-1 hydroxilated toxins, after 6 days these toxins accounted for 41% of the toxin composition. In vitro incubations of digestive glands from other commercial bivalves did not reveal production of decarbamoyl analogues over a 24 h period. PMID:17481642

  3. Shellfish toxicity in UK waters: a threat to human health?

    PubMed Central

    2009-01-01

    The potential for poisoning of humans through their consumption of shellfish which have themselves consumed biotoxin producing marine phytoplankton exists in the UK. Toxins are bio-accumulated within the shellfish flesh allowing them to reach harmful concentrations. This threat is in most part mitigated by monitoring programmes that assess both the presence of potentially harmful phytoplankton and shellfish flesh toxicity. However, the medical profession in the UK remains relatively ignorant of the potential for biotoxin derived shellfish toxicity, preventing quantification of magnitude, frequency, and severity of health effects in the community or the medical significance of more recently discovered toxins. While the current causative species and their toxins are relatively well characterised there remains a lack of understanding of the factors governing the temporal and spatial appearance of harmful phytoplankton. Expansion of shellfish aquaculture is likely both worldwide and in the UK. Better understanding of how harmful phytoplankton interact with their environment to promote the sporadic harmful blooms that we observe is required to underpin risk assessments. PMID:20102579

  4. Norovirus and other human enteric viruses in moroccan shellfish.

    PubMed

    Benabbes, Laila; Ollivier, Joanna; Schaeffer, Julien; Parnaudeau, Sylvain; Rhaissi, Houria; Nourlil, Jalal; Le Guyader, Franoise S

    2013-03-01

    The aim of this study was to evaluate the presence of human enteric viruses in shellfish collected along the Mediterranean Sea and Atlantic Coast of Morocco. A total of 77 samples were collected from areas potentially contaminated by human sewage. Noroviruses were detected in 30 % of samples, with an equal representation of GI and GII strains, but were much more frequently found in cockles or clams than in oysters. The method used, including extraction efficiency controls, allowed the quantification of virus concentration. As in previous reports, results showed levels of contamination between 100 and 1,000 copies/g of digestive tissues. Sapoviruses were detected in 13 % of samples mainly in oyster and clam samples. Hepatitis A virus was detected in two samples, with concentrations around 100 RNA copies/g of digestive tissues. Only two samples were contaminated with enterovirus and none with norovirus GIV or Aichi virus. This study highlights the interest of studying shellfish samples from different countries and different production areas. A better knowledge of shellfish contamination helps us to understand virus levels in shellfish and to improve shellfish safety, thus protecting consumers. PMID:23412717

  5. HIGH HYDROSTATIC PRESSURE PROCESSING: A POTENTIAL SOLUTION FOR SHELLFISH-BORNE VIRUSES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Molluscan shellfish bioconcentrate enteric viruses from human wastes that are present in the growing waters. Consequently, the consumption of raw shellfish poses considerable risk for contracting illnesses associated with these viruses. High hydrostatic pressure is a new nonthermal sanitizing proc...

  6. Dinophysistoxin-2: the predominant diarrhoetic shellfish toxin in Ireland.

    PubMed

    Carmody, E P; James, K J; Kelly, S S

    1996-03-01

    Diarrhoetic shellfish poisoning (DSP) in Europe is due mainly to the presence of the dinoflagellate toxin, okadaic acid (OA). However, analysis of cultivated mussels (Mytilus edulis) from southwest Ireland revealed that an isomer of OA, dinophysistoxin-2, was the major toxin present during DSP episodes. Using fluorimetric HPLC, following derivatisation with 9-anthryldiazomethane, both OA and DTX-2 were found in shellfish during a prolonged toxic episode in 1991. However, examination of similar mussel cultivation locations in 1994 showed that DTX-2 was even more predominant. During this DSP period, OA levels were less than 0.7 microgram/g, whereas maximum DTX-2 levels of 6.3 micrograms/g hepatopancreas were recorded. This toxicity in shellfish occurred soon after high cell counts of Dinophysis acuta were observed. As well as large seasonal variability in toxin levels in rope cultured mussels, substantial variations were also observed, both horizontally and vertically, within the water column. PMID:8730928

  7. When enough is not enough: shorebirds and shellfishing.

    PubMed Central

    Goss-Custard, J. D.; Stillman, R. A.; West, A. D.; Caldow, R. W. G.; Triplet, P.; le V dit Durell, S. E. A.; McGrorty, S.

    2004-01-01

    In a number of extensive coastal areas in northwest Europe, large numbers of long-lived migrant birds eat shellfish that are also commercially harvested. Competition between birds and people for this resource often leads to conflicts between commercial and conservation interests. One policy to prevent shellfishing from harming birds is to ensure that enough food remains after harvesting to meet most or all of their energy demands. Using simulations with behaviour-based models of five areas, we show here that even leaving enough shellfish to meet 100% of the birds' demands may fail to ensure that birds survive in good condition. Up to almost eight times this amount is needed to protect them from being harmed by the shellfishery, even when the birds can consume other kinds of non-harvested prey. PMID:15058432

  8. Organochlorine residues in shellfish from Maryland waters, 1976-1980.

    PubMed

    Eisenberg, M; Topping, J J

    1984-10-01

    Shellfish samples, including the American oyster (Craessostrea virginica), the soft shell clam (Mya arenaria), the hard shell clam (Mercenaria mercenaria) and the blue crab (callinectes sapidus), were taken from the Maryland section of the Chesapeake Bay and its tributaries over a five year period (1976-80) and analyzed to determine residue levels of various organochlorine pesticides. Qualitative and quantitative information was obtained for a variety of polychlorinated hydrocarbons. The purpose of this study includes the establishment of baseline values for levels of shellfish contamination, utilization of the data as an indicator of probable levels of water and sediment contamination in the vicinity of the sampling site and ensurance that shellfish harvested for human consumption are within U.S. Food and Drug Administration guidelines for organochlorine contamination. All mean values and virtually all individual values were within FDA guidelines. PMID:6501793

  9. 77 FR 36260 - Proposed Information Collection; Comment Request; Puget Sound Recreational Shellfish Harvesting...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-18

    ... an economics research project to assess the behavior of individual shellfish harvesters in response... the status of particular shellfish harvesting areas. II. Method of Collection A sample of shellfish and fishing license holders will be screened with a brief telephone survey, followed by a mail...

  10. Presence of Salmonella spp. and Campylobacter spp. in shellfish.

    PubMed

    Wilson, I G; Moore, J E

    1996-04-01

    Bivalve molluscs, (cockles, mussels, scallops and oysters) were examined according to EC shellfish bed classification regulations for faecal coliforms, Escherichia coli and salmonella, and for coliforms and campylobacter which are not specified by these regulations. Salmonella serotypes were detected in 8% of 433 molluscs. Seven salmonella isolations (2%) were made from category A beds, nominally suitable for immediate consumption according to E. coli counts. A higher percentage of salmonella isolates (6%) was detected in shellfish which require relaying or depuration prior to eating. In another survey, thermophilic Campylobacter spp. were found in 42% of 380 shellfish. These findings show bed classification on the basis of indicator organisms alone is not sufficient to assure the absence of bacterial, and no doubt viral, pathogens. Depuration and end product specifications which require the absence of salmonellae are an essential part of these regulations. Microbiologists may wish to consider whether tests for pathogens such as salmonella and campylobacter should be included when determining the suitability of shellfish for human consumption. PMID:8620905

  11. Potential virus detection and intervention methods for molluscan shellfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Norovirus is the number one cause of foodborne illness in the Unites States, causing an estimated 9 million cases/yr. Hepatitis A is uncommon in the US but can result in serious illness. Bivalve shellfish are efficient bioconcentrators of these viruses from contaminated growing waters. Consequentl...

  12. 50 CFR 14.21 - Shellfish and fishery products.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 1 2012-10-01 2012-10-01 false Shellfish and fishery products. 14.21 Section 14.21 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE...

  13. 50 CFR 14.21 - Shellfish and fishery products.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 1 2011-10-01 2011-10-01 false Shellfish and fishery products. 14.21 Section 14.21 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS IMPORTATION, EXPORTATION,...

  14. 50 CFR 14.21 - Shellfish and fishery products.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 1 2014-10-01 2014-10-01 false Shellfish and fishery products. 14.21 Section 14.21 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE...

  15. Sterol composition shellfish species commonly consumed in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Shellfish commonly consumed in the U.S. were sampled and analyzed to update nutrient data in the United States Department of Agriculture (USDA) National Nutrient Database for Standard Reference (SR), using a nationwide sampling plan and validated analytical methodology. In 2007-8, raw shrimp and se...

  16. Dinophysis Toxins: Causative Organisms, Distribution and Fate in Shellfish

    PubMed Central

    Reguera, Beatriz; Riobó, Pilar; Rodríguez, Francisco; Díaz, Patricio A.; Pizarro, Gemita; Paz, Beatriz; Franco, José M.; Blanco, Juan

    2014-01-01

    Several Dinophysis species produce diarrhoetic toxins (okadaic acid and dinophysistoxins) and pectenotoxins, and cause gastointestinal illness, Diarrhetic Shellfish Poisoning (DSP), even at low cell densities (<103 cells·L−1). They are the main threat, in terms of days of harvesting bans, to aquaculture in Northern Japan, Chile, and Europe. Toxicity and toxin profiles are very variable, more between strains than species. The distribution of DSP events mirrors that of shellfish production areas that have implemented toxin regulations, otherwise misinterpreted as bacterial or viral contamination. Field observations and laboratory experiments have shown that most of the toxins produced by Dinophysis are released into the medium, raising questions about the ecological role of extracelular toxins and their potential uptake by shellfish. Shellfish contamination results from a complex balance between food selection, adsorption, species-specific enzymatic transformations, and allometric processes. Highest risk areas are those combining Dinophysis strains with high cell content of okadaates, aquaculture with predominance of mytilids (good accumulators of toxins), and consumers who frequently include mussels in their diet. Regions including pectenotoxins in their regulated phycotoxins will suffer from much longer harvesting bans and from disloyal competition with production areas where these toxins have been deregulated. PMID:24447996

  17. Accumulation of sediment-associated viruses in shellfish.

    PubMed Central

    Landry, E F; Vaughn, J M; Vicale, T J; Mann, R

    1983-01-01

    The present study focused on the importance of contaminated sediments in shellfish accumulation of human viruses. Epifaunal (Crassostrea virginica) and infaunal (Mercenaria mercenaria) shellfish, placed on or in cores, were exposed to either resuspended or undisturbed sediments containing bound poliovirus type 1 (LSc 2ab). Consistent bioaccumulation by oysters (four of five trials) was only noted when sediment-bound viruses occurred in the water column. Virus accumulation was observed in a single instance where sediments remained in an undisturbed state. While the incidence of bioaccumulation was higher with resuspended rather than undisturbed contaminated sediment, the actual concentration of accumulated viruses was not significantly different. The accumulation of viruses from oysters residing on uninoculated sediments. When clams were exposed to undisturbed, virus-contaminated sediments, two of five shellfish pools yielded viral isolates. Bioaccumulation of undisturbed sediments by these bivalves was considered marginal when related to the concentration of virus in contaminated sediments; they would only represent a significant threat when suspended in the water column. Arguments were advanced for water-column sampling in the region of the water-sediment interface to provide an accurate determination of the virological quality of shellfish harvesting waters. PMID:6297392

  18. Dinophysis toxins: causative organisms, distribution and fate in shellfish.

    PubMed

    Reguera, Beatriz; Riob, Pilar; Rodrguez, Francisco; Daz, Patricio A; Pizarro, Gemita; Paz, Beatriz; Franco, Jos M; Blanco, Juan

    2014-01-01

    Several Dinophysis species produce diarrhoetic toxins (okadaic acid and dinophysistoxins) and pectenotoxins, and cause gastointestinal illness, Diarrhetic Shellfish Poisoning (DSP), even at low cell densities (<103 cellsL?). They are the main threat, in terms of days of harvesting bans, to aquaculture in Northern Japan, Chile, and Europe. Toxicity and toxin profiles are very variable, more between strains than species. The distribution of DSP events mirrors that of shellfish production areas that have implemented toxin regulations, otherwise misinterpreted as bacterial or viral contamination. Field observations and laboratory experiments have shown that most of the toxins produced by Dinophysis are released into the medium, raising questions about the ecological role of extracelular toxins and their potential uptake by shellfish. Shellfish contamination results from a complex balance between food selection, adsorption, species-specific enzymatic transformations, and allometric processes. Highest risk areas are those combining Dinophysis strains with high cell content of okadaates, aquaculture with predominance of mytilids (good accumulators of toxins), and consumers who frequently include mussels in their diet. Regions including pectenotoxins in their regulated phycotoxins will suffer from much longer harvesting bans and from disloyal competition with production areas where these toxins have been deregulated. PMID:24447996

  19. 50 CFR 14.21 - Shellfish and fishery products.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Shellfish and fishery products. 14.21 Section 14.21 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS IMPORTATION, EXPORTATION,...

  20. Natural modulators of Vibrios in seawater and shellfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Naturally occurring marine bacteria, Vibrio parahaemolyticus and V. vulnificus, are major threats to the safety of molluscan shellfish in the US and elsewhere. Illnesses range from mild gastrointestinal upset to septicemia and death. In studies on the uptake and persistence of V. parahaemolyticus ...

  1. Adenovirus and Norovirus Contaminants in Commercially Distributed Shellfish.

    PubMed

    Rodriguez-Manzano, Jesus; Hundesa, Ayalkibet; Calgua, Byron; Carratala, Anna; Maluquer de Motes, Carlos; Rusiol, Marta; Moresco, Vanessa; Ramos, Ana Paula; Martnez-Marca, Fernando; Calvo, Miquel; Monte Barardi, Celia Regina; Girones, Rosina; Bofill-Mas, Slvia

    2013-11-29

    Shellfish complying with European Regulations based on quantification of fecal bacterial indicators (FIB) are introduced into markets; however, information on viruses, more stable than FIB, is not available in the literature. To assess the presence of noroviruses (NoVs) GI and GII and human adenoviruses (HAdV) in domestic and imported mussels and clams (n=151) their presence was analyzed during winter seasons (2004-2008) in north-west Spanish markets through a routine surveillance system. All samples tested negative for NoV GI and 13% were positive for NoV GII. The role of HAdV as viral indicator was evaluated in 20 negative and 10 positive NoV GII samples showing an estimated sensitivity and specificity of HAdV to predict the presence of NoV GII of 100 and 74% (cut-off 0.5). The levels of HAdV and NoVs and the efficiency of decontamination in shellfish depuration plants (SDP) were evaluated analyzing pre- and post-depurated mussels collected in May-June 2010 from three different SDP. There were no statistically significant differences in the prevalence and quantification of HAdV between pre- and post-depurated shellfish and between seawater entering and leaving the depuration systems. Moreover, infectious HAdV were detected in depurated mussels. These results confirm previous studies showing that current controls and depuration treatments limiting the number of FIB do not guarantee the absence of viruses in shellfish. PMID:24293153

  2. 50 CFR 14.21 - Shellfish and fishery products.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 1 2013-10-01 2013-10-01 false Shellfish and fishery products. 14.21 Section 14.21 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS IMPORTATION, EXPORTATION,...

  3. AN RNA EXTRACTION PROTOCOL FOR SHELLFISH-BORNE VIRUSES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The GPTT virus RNA extraction method, originally developed for extraction of human norovirus and hepatitis A virus RNAs from contaminated shellfish, was evaluated for extraction of RNA from Aichi virus strain A846/88 (AiV), coxsackievirus strains A9 (CAV9) and B5 (CBV5), murine norovirus (strain MNV...

  4. 50 CFR 100.28 - Subsistence taking of shellfish.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Section 100.28 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... Subsistence Taking of Fish and Wildlife § 100.28 Subsistence taking of shellfish. (a) Covered species— (1..., on behalf of a beneficiary. (4) You may not fish with more than one legal limit of gear...

  5. 50 CFR 100.28 - Subsistence taking of shellfish.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Subsistence taking of shellfish. 100.28 Section 100.28 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) NATIONAL WILDLIFE MONUMENTS SUBSISTENCE MANAGEMENT REGULATIONS FOR PUBLIC LANDS IN ALASKA Subsistence Taking of Fish and Wildlife...

  6. Accumulation of sediment-associated viruses in shellfish

    SciTech Connect

    Landry, E.F.; Vaughn, J.M.; Vicale, T.J.; Mann, R.

    1983-01-01

    The present study focused on the importance of contaminated sediments in shellfish accumulation of human viruses. Epifaunal (Crassostrea virginica) and infanual (Mercenaria mercenaria) shellfish, placed on or in cores, were exposed to either resuspended or undisturbed sediments containing bound poliovirus type 1 (LSc 2ab). Consistent bioaccumulation by oysters (four of five trials) was only noted when sediment-bound viruses occurred in the water column. Virus accumulation was observed in a single instance where sediments remained in an undisturbed state. While the incidence of bioaccumulation was higher with resuspended rather than undisturbed contaminated sediment, the actual concentration of accumulated viruses was not significantly different from the accumulation of viruses from oysters residing on uninoculated sediments. When clams were exposed to undisturbed, virus-contaminated sediments, two of five shellfish pools yielded viral isolates. Bioaccumulation of undisturbed sediments by these bivalves was considered marginal when related to the concentration of virus in contaminated sediments; they would only represent a significant threat when suspended in the water column. Arguments were advanced for water-column sampling in the region of the water-sediment interface to provide an accurate determination of the virological quality of shellfish harvesting waters.

  7. Accumulation of sediment-associated viruses in shellfish

    SciTech Connect

    Landry, E.F.; Vaughn, J.M.; Vicale, T.J.; Mann, R.

    1983-01-01

    The present study focused on the importance of contaminated sediments in shellfish accumulation of human viruses. Epifaunal (Crassostrea virginica) and infaunal (Mercemaria mercenaria) shellfish, placed on or in cores, were exposed to either resuspended or undisturbed sediments containing bound poliovirus type 1 (LSc 2ab). Consistent bioaccumulation by oysters (four of five trials) was only noted when sediment-bound viruses occurred in the water column. Virus accumulation was observed in a single instance where sediments remained in an undisturbed state. While the incidence of bioaccumulation was higher with resuspended rather than undisturbed contaminated sediment, the actual concentration of accumulated viruses was not significantly different. The accumulation of viruses from oysters residing on uninoculated sediments. When clams were exposed to undisturbed, virus-contaminated sediments, two of five shellfish pools yielded viral isolates. Bioaccumulation of undisturbed sediments by these bivalves was considered marginal when related to the concentration of virus in contaminated sediments; they would only represent a significant threat when suspended in the water column. Arguments were advanced for water-column sampling in the region of the water-sediment interface to provide an accurate determination of the virological quality of shellfish harvesting waters.

  8. A highly rapid and simple competitive enzyme-linked immunosorbent assay for monitoring paralytic shellfish poisoning toxins in shellfish.

    PubMed

    Kawatsu, Kentaro; Kanki, Masashi; Harada, Tetsuya; Kumeda, Yuko

    2014-11-01

    Using a streptavidin-coated well plate, a biotin-labelled anti-gonyautoxin 2/3 monoclonal antibody GT-13A, and a decarbamoyl saxitoxin-peroxidase conjugate, a direct competitive enzyme-linked immunosorbent assay (PSP-ELISA) was developed for monitoring paralytic shellfish poisoning (PSP) toxins in shellfish. This assay is simple to perform and can be completed in approximately 20 min. The PSP-ELISA was compared to the mouse bioassay (MBA) for the detection of PSP toxins in shellfish samples (n=83) collected from the coast of Osaka Prefecture, Japan. When positive and negative results were indicated based on the regulatory limit for PSP toxins (4 mouse unit(MU)/g of shellfish meat), the PSP-ELISA results showed a sensitivity of 100% (25 of 25) and a specificity of 89.7% (52 of 58 samples) compared to the MBA results. These results suggest that the PSP-ELISA could be used as a rapid and simple screening method prior to the MBA. PMID:24874362

  9. Evolving to the optoelectronic mouse for phycotoxin analysis in shellfish.

    PubMed

    Campbell, Katrina; McNamee, Sara E; Huet, Anne-Catherine; Delahaut, Philippe; Vilarino, Natalia; Botana, Luis M; Poli, Mark; Elliott, Christopher T

    2014-11-01

    Despite ethical and technical concerns, the in vivo method, or more commonly referred to mouse bioassay (MBA), is employed globally as a reference method for phycotoxin analysis in shellfish. This is particularly the case for paralytic shellfish poisoning (PSP) and emerging toxin monitoring. A high-performance liquid chromatography method (HPLC-FLD) has been developed for PSP toxin analysis, but due to difficulties and limitations in the method, this procedure has not been fully implemented as a replacement. Detection of the diarrhetic shellfish poisoning (DSP) toxins has moved towards LC-mass spectrometry (MS) analysis, whereas the analysis of the amnesic shellfish poisoning (ASP) toxin domoic acid is performed by HPLC. Although alternative methods of detection to the MBA have been described, each procedure is specific for a particular toxin and its analogues, with each group of toxins requiring separate analysis utilising different extraction procedures and analytical equipment. In addition, consideration towards the detection of unregulated and emerging toxins on the replacement of the MBA must be given. The ideal scenario for the monitoring of phycotoxins in shellfish and seafood would be to evolve to multiple toxin detection on a single bioanalytical sensing platform, i.e. 'an artificial mouse'. Immunologically based techniques and in particular surface plasmon resonance technology have been shown as a highly promising bioanalytical tool offering rapid, real-time detection requiring minimal quantities of toxin standards. A Biacore Q and a prototype multiplex SPR biosensor have been evaluated for their ability to be fit for purpose for the simultaneous detection of key regulated phycotoxin groups and the emerging toxin palytoxin. Deemed more applicable due to the separate flow channels, the prototype performance for domoic acid, okadaic acid, saxitoxin, and palytoxin calibration curves in shellfish achieved detection limits (IC20) of 4,000, 36, 144 and 46 ?g/kg of mussel, respectively. A one-step extraction procedure demonstrated recoveries greater than 80% for all toxins. For validation of the method at the 95% confidence limit, the decision limits (CC?) determined from an extracted matrix curve were calculated to be 450, 36 and 24 ?g/kg, and the detection capability (CC?) as a screening method is ?10 mg/kg, ?160 ?g/kg and ?400 ?g/kg for domoic acid, okadaic acid and saxitoxin, respectively. PMID:25245418

  10. Contribution of Shellfish Consumption to Lower Mercury Health Risk for Residents in Northern Jiaozhou Bay, China.

    PubMed

    Zhang, Lei; Zhang, Lei

    2015-01-01

    Fish and marine mammal consumption are an important pathway for human exposure to mercury. The low mercury content in shellfish poses a low mercury health risk to people who consume shellfish. The objectives of this study are to detect mercury concentrations in different species of shellfish and to calculate the mercury health risk from shellfish consumption among traditional residents near northern Jiaozhou Bay. A total of 356 shellfish samples, which comprised 7 species from 5 different places in northern Jiaozhou Bay, were collected from April to June in 2012. The average mercury content in the collected shellfish ranged from 0.024?mgkg(-1) to 0.452?mgkg(-1). A total of 44 shellfish samples (12.36%) had mercury levels exceeding the national pollution-free aquatic products limit (0.3?mgkg(-1)). Generally, the viscus had the highest mercury content among all parts of the shellfish. A positive correlation between mercury content and total weight/edible part weight was found in most species of the collected shellfish. The results showed that shellfish consumption resulted in the lower risk of mercury exposure to residents based on the calculation of daily intake (DI) and target hazard quotient (THQ). PMID:26101470

  11. Contribution of Shellfish Consumption to Lower Mercury Health Risk for Residents in Northern Jiaozhou Bay, China

    PubMed Central

    2015-01-01

    Fish and marine mammal consumption are an important pathway for human exposure to mercury. The low mercury content in shellfish poses a low mercury health risk to people who consume shellfish. The objectives of this study are to detect mercury concentrations in different species of shellfish and to calculate the mercury health risk from shellfish consumption among traditional residents near northern Jiaozhou Bay. A total of 356 shellfish samples, which comprised 7 species from 5 different places in northern Jiaozhou Bay, were collected from April to June in 2012. The average mercury content in the collected shellfish ranged from 0.024 mg·kg−1 to 0.452 mg·kg−1. A total of 44 shellfish samples (12.36%) had mercury levels exceeding the national pollution-free aquatic products limit (0.3 mg·kg−1). Generally, the viscus had the highest mercury content among all parts of the shellfish. A positive correlation between mercury content and total weight/edible part weight was found in most species of the collected shellfish. The results showed that shellfish consumption resulted in the lower risk of mercury exposure to residents based on the calculation of daily intake (DI) and target hazard quotient (THQ). PMID:26101470

  12. [Paralytic shellfish toxins in shellfish from the coast of high frequent harmful algae blooms occurrence areas in East China Sea and South China Sea].

    PubMed

    Jiang, Tianjiu; Chen, Jufeng; Zou, Yinlin; Liu, Jiesheng; Yang, Weidong

    2003-07-01

    The paralytic shellfish poisoning (PSP) toxicity levels of shellfish collected from shellfish growing zones in Zhoushan areas of East China Sea and Shenzhen areas of South China Sea during January-November 2002 were determined with AOAC bioassay method. The results showed that the toxicity levels of shellfish from Zhoushan were very low, and few shellfish samples could be detected the PSP toxicities. The same levels appeared in the shellfish from Shenzhen, but the percentage of shellfish samples contaminated PSP was up to 30%, and the scallop Chalmys nobilis was dominated in the contaminated shellfish species. Analyses on the toxic profiles of digest gland and edible tissue extraction of scallop from Shenzhen showed that a similar suite of toxins presented in the gland and edible tissues. The high potency neoSTX and low potency GTX5 had a high proportions, up to 60.8% and 11.4%, respectively in the tissue, and the high potency GTX1 + 2 and GTX5 were the dominant toxins, up to 38.9% and 20%, respectively in the gland. Most of the toxin were accumulated in ingested gland of scallop, and the toxic content in gland was about 8 folds more than that in the edible tissues. PMID:14587342

  13. A Holistic Approach to the Conservation and Propagation of Freshwater, Brackish and Estuarine Bivalves for Ecosystem Services.

    NASA Astrophysics Data System (ADS)

    Kreeger, D.

    2005-05-01

    Shellfish restoration is increasingly valued in estuaries such as Chesapeake Bay where oyster populations are known to function as living biofilters, performing critical ecosystem services. Less studied are the services rendered by other suspension-feeding bivalves that reside in fringing marshes around these estuaries, in brackish and freshwater tidal portions, and in freshwater tributaries. The potential benefits contributed by other native bivalves will be discussed with two case studies from the Delaware basin. These are the ribbed mussel (Geukensia demissa ), which is abundant in brackish and marine tidal marshes, and the unionid mussel (Elliptio complanata ), which is abundant in many rivers of the system. Ribbed mussels are abundant enough to filter a large portion of the tidal prism flushing marshes, facilitating the role that these systems play as a sink for suspended solids and nutrients. Similarly, data from the lower Brandywine River suggests that a vestigial community of freshwater unionids remains sufficiently abundant to have a measurable beneficial effect on water quality by removing more than 25 metric tons of suspended particulates per year. Hence, the conservation and propagation of freshwater unionids can yield benefits that extend beyond current interest that is focused on protecting their biodiversity. Future efforts to protect or reclaim water quality and ecosystem integrity may benefit by a basin-wide, holistic approach that promotes integrated "biofiltration services" by native bivalves living from the headwaters to the coastal shelf.

  14. Copepods induce paralytic shellfish toxin production in marine dinoflagellates

    PubMed Central

    Selander, Erik; Thor, Peter; Toth, Gunilla; Pavia, Henrik

    2006-01-01

    Among the thousands of unicellular phytoplankton species described in the sea, some frequently occurring and bloom-forming marine dinoflagellates are known to produce the potent neurotoxins causing paralytic shellfish poisoning. The natural function of these toxins is not clear, although they have been hypothesized to act as a chemical defence towards grazers. Here, we show that waterborne cues from the copepod Acartia tonsa induce paralytic shellfish toxin (PST) production in the harmful algal bloom-forming dinoflagellate Alexandrium minutum. Induced A. minutum contained up to 2.5 times more toxins than controls and was more resistant to further copepod grazing. Ingestion of non-toxic alternative prey was not affected by the presence of induced A. minutum. The ability of A. minutum to sense and respond to the presence of grazers by increased PST production and increased resistance to grazing may facilitate the formation of harmful algal blooms in the sea. PMID:16769640

  15. Liquid Chromatographic Determination of Amnesic Shellfish Poison in Mussels

    NASA Astrophysics Data System (ADS)

    Duxbury, Mark

    2000-10-01

    A simple, rapid, high-performance liquid chromatographic experiment suitable for undergraduate students is described for determining amnesic shellfish poison in mussels. The poison itself is an unusual naturally occurring amino acid, domoic acid, that has been found in seafood, particularly shellfish, worldwide. The symptoms of poisoning include amnesia (memory loss), loss of balance, mental confusion, nausea, vomiting, diarrhea, coma, and in extreme cases death. The domoic acid is extracted from homogenized mussel tissue by boiling in water for 5 minutes. The homogenate is cooled and centrifuged, and an aliquot of the supernatant is diluted and analyzed by isocratic HPLC using a C18 column and an acetonitrile-water mobile phase at pH 2.5 with UV detection at 242 nm.

  16. Aquaculture and environmental stewardship: Milford shellfish biology seminar1991

    NASA Astrophysics Data System (ADS)

    Blogoslawski, Walter J.

    1992-07-01

    For the past 11 years the annual Shellfish Biology Seminar at Milford CT has provided a unique forum for aquaculture scientists and industry officials to exchange information about estuaries facing increased pollution problems, especially Long Island Sound and the Great South Bay. Because these two areas are so rich in productivity and diversity, fish and shellfish farmers utilize their waters, shellfish beds, and shore land for hatcheries and grow-out facilities. These individuals seek better management of the coastal estuarine environment and its resources, providing a working example of environmental stewardship. In aquaculture, good science is required to understand the complex variables and interaction of estuarine currents, tides, temperature, and cycles of reproduction. Aquaculturists are beginning to understand the need for specific nutrients and how the wastes of one species can be utilized for enhanced production of another species. Over the years, this meeting has formed an amalgam of both the aquaculture industry and research scientists where both groups foster mutual environmental concern. Science is able to focus on the theoretical aspects of pollutant damage. while the aquaculture industry is able to define the problem and need for assistance to eliminate pollutants from their cropsshellfish and finfish. Overfishing is not an issue at these meetings, as the group accepts the damage already done to wild resources and seeks new technologies to grow food sources under controlled and stable market conditions. Therefore, it could be said that the seminar serves as a meeting ground where the theoretical knowledge of scientific study finds practical application in the industry and is fueled by the needs of that industry. This ideal blend of the two groups produces better management of the resource and a safer environmentthe goal of stewardship.

  17. Bacterial source tracking and shellfish contamination in a coastal catchment.

    PubMed

    Geary, P M; Davies, C M

    2003-01-01

    Introduced pathogens from faecal material can make their way into the aquatic environment from a number of catchment sources. These sources typically include sewage outfalls, seepage from septic tanks, and urban and agricultural runoff. Shellfish as filter feeders are particularly susceptible to contamination in faecally contaminated waters and a range of microbiological indicators have been developed to assess the levels of contamination and likely risks to public health (Hackney and Pierson, 1994). This paper outlines the application of bacterial source tracking (BST) in a shellfish growing area in part of the Port Stephens estuary along the NSW north coast. The approach is based on the premise that bacterial isolates from different faecal sources will have significantly different resistance patterns to the battery of antibiotics and concentrations tested. Faecal streptococci (FS) were isolated from several possible faecal sources: beef and dairy cattle, chickens and humans. The resistance patterns of these isolates to four different concentrations of four antibiotics were compared to those of FS isolates obtained from samples collected upstream and in the vicinity of the oyster leases. Discriminant analysis was performed using the patterns from the known source isolates and the rate of correct classification was determined for each source. The predictive function of discriminant analysis was then used to determine the most probable source of each of the unknown isolates from Tilligerry Creek, the drainage channels to the estuary, and the shellfish leases. Preliminary results are presented here and suggest that there is no single significant source of faecal contamination, rather there are contributions from a range of sources. The findings may have implications for the ways in which land use activities and catchments are managed in similar estuarine locations with a shellfish industry. PMID:12793667

  18. N-Acetylcysteine boosts xenobiotic detoxification in shellfish.

    PubMed

    Peña-Llopis, Samuel; Serrano, Roque; Pitarch, Elena; Beltrán, Eduardo; Ibáñez, María; Hernández, Félix; Peña, Juan B

    2014-09-01

    Water pollution represents a threat of increasing importance to human health. Bivalve mollusks are filter-feeding organisms that can accumulate chemical and microbiological contaminants in their tissues from very low concentrations in the water or sediments. Consumption of contaminated shellfish is one of the main causes of seafood poisoning. Thus, marine bivalves are normally depurated in sterilized seawater for 48 h to allow the removal of bacteria. However, this depuration time might be insufficient to eliminate chemical contaminants from their tissues. We have developed a novel technology that accelerates up to fourfold the excretion rate of xenobiotics in bivalves by treatment with the antioxidant and glutathione (GSH) pro-drug N-acetylcysteine (NAC) during the depuration period. NAC improved dose-dependently the detoxification of the organophosphate (OP) pesticide fenitrothion in the mussel Mytilus galloprovincialis, diminishing its levels up to nearly a hundred fold compared to conventional depuration, by enhancing the glutathione S-transferase (GST) activity and inducing the GSH anabolism (GSH synthesis and reduction by glutathione reductase). Notably, this induction in GSH anabolism and GST activity was also observed in uncontaminated bivalves treated with NAC. As the GSH pathway is involved in the detoxification of many pollutants and biotoxins from harmful algal blooms, we validated this proof of principle in king scallops (Pecten maximus) that naturally accumulated the amnesic shellfish poisoning (ASP) toxin domoic acid. We illustrate here a method that enhances the elimination of organic contaminants in shellfish, opening new avenues of depuration of marine organisms. PMID:24880785

  19. Shellfish: Toxicology studies. (Latest citations from the NTIS Bibliographic database). Published Search

    SciTech Connect

    Not Available

    1993-12-01

    The bibliography contains citations concerning the effects of toxic substances on shellfish. Petroleum products, solvents, sewage, copper, mercury, chromium, dredged materials, and organic chemicals are among the toxic substances studied. Reproductive impairment, molting behavior, and population reduction caused by toxic chemicals are discussed. Shellfish as bioindicators and shellfish tolerance to toxic substances are briefly considered. (Contains 250 citations and includes a subject term index and title list.)

  20. Shellfish: toxicology studies. October 1982-May 1988 (Citations from the NTIS data base). Report for October 1982-May 1988

    SciTech Connect

    Not Available

    1988-05-01

    This bibliography contains citations concerning the effects of toxic substances on shellfish. Petroleum products, solvents, sewage, copper, mercury, chromium, dredged materials, and organic chemicals are among the toxic substances studied. Reproductive impairement, molting behavior, and population reduction caused by toxic chemicals are discussed. Shellfish as bioindicators and shellfish tolerance to toxic substances are briefly considered. Shellfish farming and economics are covered in a separate bibliography. (Contains 108 citations fully indexed and including a title list.)

  1. Quantitation of diarrhetic shellfish poisoning toxins in Chilean mussel using pyrenyldiazomethane as fluorescent labeling reagent.

    PubMed

    Garca, Carlos; Pereira, Paulo; Valle, Luis; Lagos, Nstor

    2003-01-01

    Diarrhetic shellfish poisoning (DSP) is a gastrointestinal disease caused by lipid soluble polyether toxins produced by dinoflagellates and accumulated in shellfish. Diarrhetic shellfish poisoning is a worldwide threat to public health and the shellfish industry. To date, only four lipid soluble polyethers have been known as diarrhetic shellfish toxins. Among them, Okadaic acid (OA), Dinophysistoxin 1 (DTX-1, 35-methyl OA), Dinophysistoxin 2 (DTX-2, OA isomers) and Dinophysistoxin 3 (DTX-3, 7-O-acyl-35-methyl OA), all of which have free carboxilic groups. To perform quantitative analysis of DSP toxins in shellfish samples is a requirement, because DSP toxins are endemic in the Chilean mollusks of the southern regions, and although human symptoms of DSP appear relatively mild in comparison with the Paralytic Shellfish Poisoning (PSP), the necessity of monitoring the chronic effects of continued uptake of low doses of DSP toxins more closely is imperative, since DSP toxins have been described as potent tumor promoters. This paper shows the synthesis pathway of a chromophore, 1-pyrenyldiazomethane (PDAM), a fluorescent labeling reagent for determination of carboxilic acids, using High Performance Liquid Chromatography with fluorescence on-line detection. This procedure was developed in order to have a quantitative method for DSP toxins analysis that would be useful for health public services and private shellfish industries. The features of this labeling reagent are compared against ADAM and used for quantitative analysis of DSP toxins in Chilean mussels and cultured dinoflagellates samples. PMID:14513712

  2. 75 FR 28858 - Agency Information Collection (Purchase of Shellfish) Activities Under OMB Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-24

    ....Regulations.gov ; or to VA's OMB Desk Officer, OMB Human Resources and Housing Branch, New Executive Office... furnishing shellfish to VA must ensure that the shellfish is packaged in a container that is marked with the... container is tagged or labeled indicating the name and address of the approved producer or shipper, the...

  3. Seasonal variation of bacterial communities in shellfish harvesting waters: preliminary study before applying phage therapy.

    PubMed

    Pereira, C; Santos, L; Silva, A P; Silva, Y J; Cunha, A; Romalde, J L; Nunes, M L; Almeida, A

    2015-01-15

    The recurrent emergence of infections outbreaks associated with shellfish consumption is an important health problem, which results in substantial economic losses to the seafood industry. Even after depuration, shellfish is still involved in outbreaks caused by pathogenic bacteria, which increases the demand for new efficient strategies to control the shellfish infection transmission. Phage therapy during the shellfish depuration is a promising approach, but its success depends on a detailed understanding of the dynamics of bacterial communities in the harvesting waters. This study intends to evaluate the seasonal dynamics of the overall bacterial communities, disease-causing bacterial populations and bacterial sanitary quality indicators in two authorized harvesting-zones at Ria de Aveiro. During the hot season, the total bacterial community presented high complexity and new prevalent populations of the main shellfish pathogenic bacteria emerged. These results indicate that the spring/summer season is a critical period during which phage therapy should be applied. PMID:25484114

  4. Probabilistic dietary exposure to phycotoxins in a recreational shellfish harvester subpopulation (France).

    PubMed

    Picot, Cyndie; Limon, Gwendolina; Durand, Gal; Parent-Massin, Dominique; Roudot, Alain-Claude

    2013-07-01

    Phycotoxins, secondary phytoplankton metabolites, are considered as an important food safety issue because their accumulation by shellfish may render them unfit for human consumption. However, the likely intakes of phycotoxins via shellfish consumption are almost unknown because both contamination and consumption data are very scarce. Thus, two 1-year surveys were conducted (through the same population: recreational shellfish harvesters and from the same geographical area) to assess: shellfish consumption and contamination by major toxins (domoic acid (DA) group, okadaic acid (OA) group and spirolides (SPXs)). Recreational shellfish harvesters had been targeted as an at-risk subpopulation because they consume more shellfish than general population and because they eat not only commercial shellfish species controlled by official authorities but also their own harvests of shellfish species may be in non-controlled areas and more over shellfish species non-considered in the official control species. Then, these two kinds of data were combined with deterministic and probabilistic approaches for both acute and chronic exposures, on considering the impact of shellfish species and cooking on phycotoxin levels. For acute risk, monitoring programs seem to be adequate for DAs, whereas OAs could be a matter of concern for high consumers (their acute intakes were up to ninefold the acute reference dose (ARfD)). About chronic risk, OAs are a matter of concern. The daily OAs intakes were close to the ARfD, which is, by definition, greater than the tolerable daily intake. Moreover, SPX contamination is low but regular, no (sub)chronic SPX toxicity data exist; but in case of (sub)chronic toxicity, SPX exposure should be considered. PMID:22760440

  5. [Carrying capacity of shellfish culture in Dadeng Island sea area of Xiamen].

    PubMed

    Lu, Zhenbin; Du, Qi; Fang, Minjie; Qian, Xiaoming; Cai, Qinghai; Xu, Cuiya

    2005-05-01

    To fully and rationally exploit local living marine resources while have a sustainable, efficient and healthy development of shellfish culture in the Dadeng Island sea area of Xiamen, this paper determined and analyzed the related model parameters of this area, including chlorophyll a, primary productivity, phytoplankton organic carbon tent, wild filter feeder yields in subtidal and intertidal zones and suspension culture area, cultured shellfish filtration rate and organic carbon content, shellfish's total weight to fresh meat ratio, and adopted the Nutrient namic Model and Coastal Waters' Energy Flow Analysis Model to estimate the ecological capacity of shellfish this area, from which, the wild filter feeder yields were deducted for estimating shellfish carrying capacity. model established by Fang Jianguang was also used to estimate the shellfish carrying capacity. Statistics analysis was used to estimate the suitable culture area of shellfish and other species, aiming at limiting local shellfish ture and optimizing the culture of various species mollusks. According to the estimation of the three models, shellfish carrying capacity in this area should be 35,248-39,990 tons, with an average of 37,488 tons, 140,008 x 10(4) - 158,850 x 10(4) individuals, averaging 148,903 x 10(4). The theoretically suitable culture area 2 145 hm2, 1,900 hm2 for Ostreidae, 81 hm2 for razor clam (Sinonovacula constricta), 20 hm2 for blood (Tegillarca granosa), and 144 hm2 for musculus (Musculus senhousei). In 2000, the actual culture area of shellfish and other species in the waters around Dadeng surpassed the estimated suitable culture area. It is proposed that some measures should be taken to reduce the overexploited area. PMID:16110680

  6. Non-Traditional Vectors for Paralytic Shellfish Poisoning

    PubMed Central

    Deeds, Jonathan R.; Landsberg, Jan H.; Etheridge, Stacey M.; Pitcher, Grant C.; Longan, Sara Watt

    2008-01-01

    Paralytic shellfish poisoning (PSP), due to saxitoxin and related compounds, typically results from the consumption of filter-feeding molluscan shellfish that concentrate toxins from marine dinoflagellates. In addition to these microalgal sources, saxitoxin and related compounds, referred to in this review as STXs, are also produced in freshwater cyanobacteria and have been associated with calcareous red macroalgae. STXs are transferred and bioaccumulate throughout aquatic food webs, and can be vectored to terrestrial biota, including humans. Fisheries closures and human intoxications due to STXs have been documented in several non-traditional (i.e. non-filter-feeding) vectors. These include, but are not limited to, marine gastropods, both carnivorous and grazing, crustacea, and fish that acquire STXs through toxin transfer. Often due to spatial, temporal, or a species disconnection from the primary source of STXs (bloom forming dinoflagellates), monitoring and management of such non-traditional PSP vectors has been challenging. A brief literature review is provided for filter feeding (traditional) and non-filter feeding (non-traditional) vectors of STXs with specific reference to human effects. We include several case studies pertaining to management actions to prevent PSP, as well as food poisoning incidents from STX(s) accumulation in non-traditional PSP vectors. PMID:18728730

  7. Biogenic amines in fish, fish products and shellfish: a review.

    PubMed

    Prester, Ljerka

    2011-11-01

    Fish, cephalopods and shellfish provide a healthy source of high-quality proteins, essential vitamins, minerals and polyunsaturated fatty acids. The beneficial effects of fish consumption on human health such as protection against coronary heart disease and certain cancer may be offset by fish decomposition and the formation of chemical contaminants such as biogenic amines. There are several toxicological effects of biogenic amines on humans, especially histamine. It is the causative agent of histamine or scombroid fish poisoning which is a significant public health problem. In individuals with diminished histamine detoxification, ingestion of even a low or moderate histamine- or tyramine-containing fish may lead to food intolerance. Biogenic amines such as putrescine, tyramine and cadaverine can potentiate histamine toxicity. Furthermore, dietary polyamine intake should be minimised in some cancer patients. Besides their potential toxicity, biogenic amines are used for the evaluation of hygienic quality of different marine and freshwater species. Spoilage pattern and biogenic amine formation are species specific. Histamine has been traditionally used as an indicator of the quality of histidine-rich fish (dark-muscle fish). On the other hand, putrescine and cadaverine are the most objective indicators of quality of histidine-poor fish (white-muscle fish), shellfish and fermented seafood products. PMID:21834642

  8. Enteric viruses in a mangrove lagoon, survival and shellfish incidence

    SciTech Connect

    Lopez de Cardona, I.; Bermudez, M.; Billmire, E.; Hazen, T.C.

    1988-12-31

    Mangrove oysters (Crassostrea rhizophorae) were screened for enteric viruses. For 18 months oysters were collected from Cano Boqueron, a tropical mangrove lagoon on the southwest coast of Puerto Rico. This popular tourist resort has two primary sewage treatment plants which service 158 single family cabanas. In spite of the heavy seasonal input of sewage to Cano Boqueron and high densities of fecal coliform bacteria, enteric viruses were not detected in shellfish meat. Because no viruses were detected in the oysters, a virus survival study was performed. Poliovirus type 1 was placed in diffusion chambers in situ at two sites in Cano Boqueron. More than 95% of the poliovirus inactivation occurred within 24 h. Virus inactivation was significantly different by site, indicating different inactivation rates within the lagoon. Chamber studies done simultaneously with Escherichia coli did not reveal differences between sites. It is suggested that the sewage effluent had an antiviral effect in the absence of an antibacterial effect. This study demonstrates the importance for establishing microbial contamination standards for shellfish growing waters in the tropics based upon in situ studies with tropical species, e.g. mangrove oyster.

  9. Artificial Neural Network Prediction of Viruses in Shellfish

    PubMed Central

    Brion, Gail; Viswanathan, Chandramouli; Neelakantan, T. R.; Lingireddy, Srinivasa; Girones, Rosina; Lees, David; Allard, Annika; Vantarakis, Apostolos

    2005-01-01

    A database was probed with artificial neural network (ANN) and multivariate logistic regression (MLR) models to investigate the efficacy of predicting PCR-identified human adenovirus (ADV), Norwalk-like virus (NLV), and enterovirus (EV) presence or absence in shellfish harvested from diverse countries in Europe (Spain, Sweden, Greece, and the United Kingdom). The relative importance of numerical and heuristic input variables to the ANN model for each country and for the combined data was analyzed with a newly defined relative strength effect, which illuminated the importance of bacteriophages as potential viral indicators. The results of this analysis showed that ANN models predicted all types of viral presence and absence in shellfish with better precision than MLR models for a multicountry database. For overall presence/absence classification accuracy, ANN modeling had a performance rate of 95.9%, 98.9%, and 95.7% versus 60.5%, 75.0%, and 64.6% for the MLR for ADV, NLV, and EV, respectively. The selectivity (prediction of viral negatives) was greater than the sensitivity (prediction of viral positives) for both models and with all virus types, with the ANN model performing with greater sensitivity than the MLR. ANN models were able to illuminate site-specific relationships between microbial indicators chosen as model inputs and human virus presence. A validation study on ADV demonstrated that the MLR and ANN models differed in sensitivity and selectivity, with the ANN model correctly identifying ADV presence with greater precision. PMID:16151110

  10. Detection of the marine toxins okadaic acid and domoic acid in shellfish and phytoplankton in the Gulf of Mexico.

    PubMed

    Dickey, R W; Fryxell, G A; Granade, H R; Roelke, D

    1992-03-01

    Liquid chromatographic analyses of extracts from shellfish and phytoplankton from the Gulf of Mexico indicated the presence of the marine toxins okadaic acid (0.162 microgram/g shellfish) and domoic acid (2.1 pg/cell phytoplankter). These toxins are causative agents of diarrhetic shellfish poisoning (DSP) and amnesic shellfish poisoning (ASP), respectively. The presence of DSP and ASP toxins in a region with no previous record of outbreaks may indicate a potential for human poisoning under conditions appropriate for accumulation of these toxins in shellfish. PMID:1529467

  11. Testing and application of a refined rapid detection method for paralytic shellfish poisoning toxins in UK shellfish.

    PubMed

    Turner, Andrew D; Tarnovius, Sophie; Johnson, Sarah; Higman, Wendy A; Algoet, Myriam

    2015-06-15

    The Scotia Rapid Test for PSP is designed for qualitative identification of saxitoxins at levels in shellfish equivalent to the limit of detection of the biological reference method. However, issues with the method have been reported, including the low assay cross reactivity for some toxins, high numbers of false positive results and the subjective test interpretation. This study focussed on approaches to improve each of these issues. A refined test was found to improve GTX1&4 test sensitivity in samples containing high proportions of GTX1&4. The subjectivity of the test was successfully eliminated through use of an automated scanner, which enabled both the reliable identification of test results as well as the provision of a numerical result which could be utilised for more refined results interpretation. Finally the high proportion of false positive results in comparison with the LC-FLD was investigated, with a modified approach incorporating an additional extract dilution applied to a range of shellfish samples with different toxicities. Results showed highly variable limits of detection of the method and no significant reduction in false positive results when applying the additional dilution, which may be of concern to laboratories in receipt of high numbers of samples containing low concentrations of toxins. PMID:25912947

  12. Microbiological quality of frozen breaded fish and shellfish products.

    PubMed

    Baer, E F; Duran, A P; Leininger, H V; Read, R B; Schwab, A H; Swartzentruber, A

    1976-03-01

    A survey was made of the microbiological quality of seven frozen, breaded, precooked fish and shellfish products and of frozen, breaded, uncooked shrimp at the retail level. Geometric mean aerobic plate counts per gram (and number of units examined) were as follows: fish sticks, 8,300 (1,539); fish cakes, 5,600 (1,378); crab cakes, 4,900 (1,226); scallops, 1,700 (1,392); clams, 450 (1,384); haddock, 15,000 (1,306); fish in fish and chips dinner, 7,200 (1,485); and uncooked shrimp, 220,000 (1,462). Geometric mean coliform, Escherichia coli, and Staphylococcus aureus counts for all eight products ranged from 1 to 10/g. PMID:779643

  13. Phycotoxins: chemistry, mechanisms of action and shellfish poisoning.

    PubMed

    Rossini, Gian Paolo; Hess, Philipp

    2010-01-01

    Phycotoxins are natural metabolites produced by micro-algae. Through accumulation in the food chain, these toxins may concentrate in different marine organisms, including filter-feeding bivalves, burrowing and grazing organisms, herbivorous and predatory fish. Human poisoning due to ingestion of seafood contaminated by phycotoxins has occurred in the past, and harmful algal blooms (HABs) are naturally occurring events. Still, we are witnessing a global increase in HABs and seafood contaminations, whose causative factors are only partially understood. Phycotoxins are small to medium-sized natural products and belong to many different groups of chemical compounds. The molecular mass ranges from approximately 300 to over 3000 Da, and the compound classes represented include amino acids, alkaloids and polyketides. Each compound group typically has several main compounds based on the same or similar structure. However, most groups also have several analogues, which are either produced by the algae or through metabolism in fish or shellfish or other marine organisms. The different phycotoxins have distinct molecular mechanisms of action. Saxitoxins, ciguatoxins, brevetoxins, gambierol, palytoxins, domoic acid, and, perhaps, cyclic imines, alter different ion channels and/or pumps at the level of the cell membrane. The normal functioning of neuronal and other excitable tissues is primarily perturbed by these mechanisms, leading to adverse effects in humans. Okadaic acid and related compounds inhibit serine/threonine phosphoprotein phosphatases, and disrupt major mechanisms controlling cellular functions. Pectenotoxins bind to actin filaments, and alter cellular cytoskeleton. The precise mechanisms of action of yessotoxins and azaspiracids, in turn, are still undetermined. The route of human exposure to phycotoxins is usually oral, although living systems may become exposed to phycotoxins through other routes. Based on recorded symptoms, the major poisonings recognized so far include paralytic, neurotoxic, amnesic, diarrheic shellfish poisonings, ciguatera, as well as palytoxin and azaspiracid poisonings. PMID:20358682

  14. Monitoring brevetoxins during a Gymnodinium breve red tide: comparison of sodium channel specific cytotoxicity assay and mouse bioassay for determination of neurotoxic shellfish toxins in shellfish extracts.

    PubMed

    Dickey, R; Jester, E; Granade, R; Mowdy, D; Moncreiff, C; Rebarchik, D; Robl, M; Musser, S; Poli, M

    1999-01-01

    In October of 1996, a Gymnodinium breve bloom occurred in shellfish harvesting waters of Alabama, Mississippi and Louisiana, Gulf of Mexico, USA. Bloom densities reached 5.6x10(5) cells liter(-1) and bloom residence at shellfish sampling stations ranged from 3 to 28 days. Brevetoxin-2 dominated G. breve toxin profiles in bloom seawater extracts. Shellfish toxicity, assessed by mouse bioassay, exceeded the guidance level for up to 75 days after the bloom had dissipated. Cytotoxicity assays and mouse bioassays showed similar temporal patterns of shellfish toxicity, but the two methods differed in estimations of brevetoxin-3 equivalent toxicity by a factor of 93 to 1. LC-ESI-MS showed the temporal patterns in shellfish toxicity reflected metabolism of G. breve toxins. The molecular ions m/z 1004, 1017 and 1033 dominated LC-ESI-MS spectra of toxic chromatographic fractions from the extracts and were identified as brevetoxin metabolites on the basis of LC-APCI-MS-MS. The discrepancy between cytotoxicity and mouse bioassay estimates of brevetoxin-3 equivalent toxicity resulted from the difference in extraction efficiency of solvents used in the respective methods and the relative sensitivity of the assays to toxin metabolite mixtures present in the extracts. The normalized cytotoxicity assay showed 75% agreement with mouse bioassay positive test samples and 64% agreement with mouse bioassay negative test samples. Published in 1999 by John Wiley & Sons, Ltd. PMID:10797644

  15. Discover the Atlantic Ocean: An Exciting Coloring Book of Fish and Shellfish.

    ERIC Educational Resources Information Center

    Flick, George J.

    This coloring book contains pictures of more than 79 fish and shellfish found on the Atlantic Coast. Captions give information on habitats, behavior, or commercial uses of the species pictured. Indexes of both common and scientific names are given. (BB)

  16. High pressure processing of bivalve shellfish and HPP's potential use as a virus intervention

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bivalve shellfish readily bioconcentrate pathogenic microbes and substance, such as algal and dinoflagulate toxins, fecal viruses and bacteria, and naturally present vibrio bacteria. High pressure processing (HPP) is currently used as an intervention for Vibrio vulnificus bacteria within molluscan ...

  17. PECONIC ESTUARY: AN ASSESSMENT OF SHELLFISH RESOURCES IN THE TRIBUTARIES AND EMBAYMENTS OF THE PECONIC ESTUARY

    EPA Science Inventory

    Executive Summary Historically, the Peconic Estuary's shellfish resources have supported significant fisheries for a number of species including hard clams, oysters and bay scallops. However, distribution and abundance data for the tributaries and embayments within the Peconic Es...

  18. Processing Strategies to Inactivate Enteric Viruses in Shellfish: Limitations of Surrogate Viruses and Molecular Methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Noroviruses, hepatitis A and E viruses, sapovirus, astrovirus, rotavirus, Aichi virus, enteric adenoviruses, poliovirus, and other enteroviruses enter shellfish through contaminated seawater or by contamination during handling and processing, resulting in outbreaks ranging from isolated to epidemic....

  19. Evaluation of potential indicators of viral contamination in shellfish and their applicability to diverse geographical areas.

    PubMed

    Formiga-Cruz, M; Allard, A K; Conden-Hansson, A-C; Henshilwood, K; Hernroth, B E; Jofre, J; Lees, D N; Lucena, F; Papapetropoulou, M; Rangdale, R E; Tsibouxi, A; Vantarakis, A; Girones, R

    2003-03-01

    The distribution of the concentration of potential indicators of fecal viral pollution in shellfish was analyzed under diverse conditions over 18 months in diverse geographical areas. These microorganisms have been evaluated in relation to contamination by human viral pathogens detected in parallel in the analyzed shellfish samples. Thus, significant shellfish-growing areas from diverse countries in the north and south of Europe (Greece, Spain, Sweden, and the United Kingdom) were defined and studied by analyzing different physicochemical parameters in the water and the levels of Escherichia coli, F-specific RNA bacteriophages, and phages infecting Bacteroides fragilis strain RYC2056 in the shellfish produced, before and after depuration treatments. A total of 475 shellfish samples were studied, and the results were statistically analyzed. According to statistical analysis, the presence of human viruses seems to be related to the presence of all potential indicators in the heavily contaminated areas, where E. coli would probably be suitable as a fecal indicator. The F-RNA phages, which are present in higher numbers in Northern Europe, seem to be significantly related to the presence of viral contamination in shellfish, with a very weak predictive value for hepatitis A virus, human adenovirus, and enterovirus and a stronger one for Norwalk-like virus. However, it is important to note that shellfish produced in A or clean B areas can sporadically contain human viruses even in the absence of E. coli or F-RNA phages. The data presented here will be useful in defining microbiological parameters for improving the sanitary control of shellfish consumed raw or barely cooked. PMID:12620843

  20. A feasibility study into the provision of Paralytic Shellfish Toxins laboratory reference materials by mass culture of Alexandrium and shellfish feeding experiments.

    PubMed

    Higman, Wendy A; Turner, Andrew

    2010-09-15

    As the official control laboratory for biotoxin testing in England, Wales and Scotland, Cefas employs two approaches for the detection of Paralytic Shellfish Poisons (PSP) in bivalve shellfish: a qualitative HPLC method for oysters, whole king scallops and cockles (with PSP bioassay confirmation of positive HPLC samples) with subsequent quantitation of positive samples by mouse bioassay and a quantitative HPLC method for mussels (no PSP bioassay confirmation required). To aid the validation of the quantitative HPLC method for native oysters, Pacific oysters, cockles and king scallops and ultimately remove the need for the PSP bioassay for these species, appropriate contaminated shellfish matrices were required. As it was not possible to obtain naturally contaminated material for these species, shellfish were contaminated in-house through feeding experiments with high concentrations of Alexandrium species. A number of feeding experiments with two Alexandrium strains were performed successfully. The contaminated shellfish materials generated contained a number of different profiles of PSP toxins. This work has demonstrated the feasibility of these methods for the production of laboratory reference materials in a variety of bivalve shellfish species. Based on this study laboratory reference material production via these methods is now undertaken routinely within Cefas. By running two concurrent feeding trials per year for each species, enough laboratory reference material is produced for approximately 1 year of the programme. This removes the necessity for natural contaminated material which is not always available for reference material production. Additionally, such materials enable both the comparative testing of different PSP methodologies and the ongoing generation of long-term precision data for the HPLC method. PMID:20493202

  1. Screening Tests for the Rapid Detection of Diarrhetic Shellfish Toxins in Washington State

    PubMed Central

    Eberhart, Bich-Thuy L.; Moore, Leslie K.; Harrington, Neil; Adams, Nicolaus G.; Borchert, Jerry; Trainer, Vera L.

    2013-01-01

    The illness of three people due to diarrhetic shellfish poisoning (DSP) following their ingestion of recreationally harvested mussels from Sequim Bay State Park in the summer of 2011, resulted in intensified monitoring for diarrhetic shellfish toxins (DSTs) in Washington State. Rapid testing at remote sites was proposed as a means to provide early warning of DST events in order to protect human health and allow growers to test “pre-harvest” shellfish samples, thereby preventing harvest of toxic product that would later be destroyed or recalled. Tissue homogenates from several shellfish species collected from two sites in Sequim Bay, WA in the summer 2012, as well as other sites throughout Puget Sound, were analyzed using three rapid screening methods: a lateral flow antibody-based test strip (Jellett Rapid Test), an enzyme-linked immunosorbent assay (ELISA) and a protein phosphatase 2A inhibition assay (PP2A). The results were compared to the standard regulatory method of liquid chromatography coupled with tandem mass spectroscopy (LC-MS/MS). The Jellett Rapid Test for DSP gave an unacceptable number of false negatives due to incomplete extraction of DSTs using the manufacturer’s recommended method while the ELISA antibody had low cross-reactivity with dinophysistoxin-1, the major toxin isomer in shellfish from the region. The PP2A test showed the greatest promise as a screening tool for Washington State shellfish harvesters. PMID:24084788

  2. Detection of sapoviruses and noroviruses in an outbreak of gastroenteritis linked genetically to shellfish.

    PubMed

    Iizuka, Setsuko; Oka, Tomoichiro; Tabara, Kenji; Omura, Tamaki; Katayama, Kazuhiko; Takeda, Naokazu; Noda, Mamoru

    2010-07-01

    Norovirus (NoV) and sapovirus (SaV) are important pathogens of human gastroenteritis. Compared to NoV, the transmission route of SaV is unclear. An outbreak of gastroenteritis occurred at a restaurant in June 2008, and SaV and NoV were detected in fecal specimens from 17 people who ate at the restaurant and one asymptomatic food handler and also in stripped shellfish and liquids remaining in the shellfish packages by reverse transcription-polymerase chain reaction (RT-PCR) and/or real-time RT-PCR. Nucleotide sequencing analysis of the RT-PCR products corresponding to the partial capsid region revealed 99.3-100% identities for SaV and 98.6-99.3% identities for NoV among the digestive diverticulum of the frozen stripped shellfish (Ruditapes philippinarum), "Asari," the package liquid, and feces from symptomatic or asymptomatic guests. These results suggested a link between the consumption of contaminated shellfish and clinical features in the patients. While the transmission of NoV by shellfish has been reported, this report shows that SaV can also be transmitted by shellfish. PMID:20513092

  3. Trends in the levels of Escherichia coli in commercially harvested bivalve shellfish from England and Wales, 1999-2008.

    PubMed

    Campos, Carlos J A; Acornley, Richard; Morgan, Owen C; Kershaw, Simon

    2013-02-15

    Temporal trends in Escherichia coli concentrations in bivalve shellfish were examined using data collected from 57 production areas around the coast of England and Wales during 1999-2008. Downward trends were detected in annual geometric means of E. coli in shellfish from 12% of the sampling points. The percentage of class B areas (E. coli ≤ 4600/100 g shellfish in 90% of samples) increased from 69% to 86% during the 10-year period. The improvement in the microbial quality of shellfish is associated with sewerage improvement schemes largely implemented during 2000-2005. Upward trends were detected in 9% of the points. The causes of these increases are not known. It is recommended that quantitative sanitary profiling of shellfish waters and cost-benefit appraisal over long-term planning horizons are considered as part of sewerage investment programmes under the Water Framework Directive. This would allow greater scope to secure protection and improvement of shellfish water quality. PMID:23260652

  4. Derivation of shellfish harvest reopening criteria following the New Carissa oil spill in Coos Bay, Oregon.

    PubMed

    Gilroy, D J

    2000-07-14

    Oil spills in Alaska, California, Maine, and other states have raised concerns regarding potential contamination of fish and shellfish, and have led to temporary closures of seafood harvests while health risks are assessed. Lacking standardized protocols, these assessments are generally ad hoc, site-specific efforts, with significant differences in risk evaluation criteria. This article describes the response of a state health agency to shellfish contamination following an oil spill on the Oregon coast, and discusses some of the factors that can complicate the evaluation of potential health risks from consumption of oil-contaminated shellfish. On 4 February 1999, the Japanese-owned cargo ship M/V New Carissa, carrying an estimated 400,000 gallons of light diesel and heavy fuel oil, ran aground 2 miles north of Coos Bay, Oregon. Damage to the ship's hull from the grounding and pounding surf caused the release of an estimated 25,000 to 70,000 gallons of oil. Concern for potential contamination of local recreational shellfish and commercial oyster beds prompted the Oregon Department of Agriculture (ODA) to close shellfish harvesting in Coos and Douglas counties. ODA requested assistance from the Oregon Health Division in the derivation of risk-based criteria for reopening the shellfish harvest. Criteria were developed for the primary contaminants of concern, polycyclic aromatic hydrocarbons (PAHs) expressed as total benzo[a]-pyrene (BaP) equivalents. "Safe" (<10 microg/kg) and "unsafe" (>45 microg/kg) BaP equivalent levels were derived based on upper end (32.5 g/d) and average (7.5 g/d) estimates of shellfish consumption, respectively. Composite samples of oysters, clams, and mussels (15-20 per composite) were collected from target areas and analyzed for PAHs by gas chromatography/mass spectroscopy (GC/MS). Carcinogenic PAHs were converted to total BaP equivalents (wet weight) and compared with criteria. Two oyster samples, collected from a slough off of Coos Bay, contained 33.9 and 34.5 microg/kg BaP equivalents; all other samples had less than 10 microg/kg BaP equivalents. An evaluation of the PAH profiles in the two higher oyster samples indicated a primary source other than the New Carissa oil. Because shellfish sample BaP equivalents attributable to the New Carissa oil spill did not exceed 10 microg/kg, shellfish harvesting was reopened on 4 March 1999. This study revealed some of the inherent difficulties in attempting to quantify health risks from contaminated shellfish following an oil spill and demonstrated the clear need for standardized protocols for responding to such events. PMID:10912585

  5. Removal of Paralytic Shellfish Toxins by Probiotic Lactic Acid Bacteria

    PubMed Central

    Vasama, Mari; Kumar, Himanshu; Salminen, Seppo; Haskard, Carolyn A.

    2014-01-01

    Paralytic shellfish toxins (PSTs) are non-protein neurotoxins produced by saltwater dinoflagellates and freshwater cyanobacteria. The ability of Lactobacillus rhamnosus strains GG and LC-705 (in viable and non-viable forms) to remove PSTs (saxitoxin (STX), neosaxitoxin (neoSTX), gonyautoxins 2 and 3 (GTX2/3), C-toxins 1 and 2 (C1/2)) from neutral and acidic solution (pH 7.3 and 2) was examined using HPLC. Binding decreased in the order of STX ~ neoSTX > C2 > GTX3 > GTX2 > C1. Removal of STX and neoSTX (77%–97.2%) was significantly greater than removal of GTX3 and C2 (33.3%–49.7%). There were no significant differences in toxin removal capacity between viable and non-viable forms of lactobacilli, which suggested that binding rather than metabolism is the mechanism of the removal of toxins. In general, binding was not affected by the presence of other organic molecules in solution. Importantly, this is the first study to demonstrate the ability of specific probiotic lactic bacteria to remove PSTs, particularly the most toxic PST-STX, from solution. Further, these results warrant thorough screening and assessment of safe and beneficial microbes for their usefulness in the seafood and water industries and their effectiveness in vivo. PMID:25046082

  6. Paralytic shellfish poisoning: seafood safety and human health perspectives.

    PubMed

    Etheridge, Stacey M

    2010-08-15

    Paralytic shellfish poisoning (PSP) is the foodborne illness associated with the consumption of seafood products contaminated with the neurotoxins known collectively as saxitoxins (STXs). This family of neurotoxins binds to voltage-gated sodium channels, thereby attenuating action potentials by preventing the passage of sodium ions across the membrane. Symptoms include tingling, numbness, headaches, weakness and difficulty breathing. Medical treatment is to provide respiratory support, without which the prognosis can be fatal. To protect human health, seafood harvesting bans are in effect when toxins exceed a safe action level (typically 80 microg STX eq 100 g(-1) tissue). Though worldwide fatalities have occurred, successful management and monitoring programs have minimized PSP cases and associated deaths. Much is known about the toxin sources, primarily certain dinoflagellate species, and there is extensive information on toxin transfer to traditional vectors - filter-feeding molluscan bivalves. Non-traditional vectors, such as puffer fish and lobster, may also pose a risk. Rapid and reliable detection methods are critical for toxin monitoring in a wide range of matrices, and these methods must be appropriately validated for regulatory purposes. This paper highlights PSP seafood safety concerns, documented human cases, applied detection methods as well as monitoring and management strategies for preventing PSP-contaminated seafood products from entering the food supply. PMID:20035780

  7. Protein markers of algal toxin contamination in shellfish.

    PubMed

    Ronzitti, Giuseppe; Milandri, Anna; Scortichini, Giampiero; Poletti, Roberto; Rossini, Gian Paolo

    2008-11-01

    Filter-feeding bivalve molluscs are often contaminated by algal toxins. We have probed whether proteomic analysis of extracts from the digestive gland (DG) of mussels could be employed to identify biomarkers of contamination due to okadaic acid-group toxins. The protein extracts were obtained from 18 separate mussel samples and were analyzed by two-dimensional gel electrophoresis. When samples were divided into four different classes based on the content of OA-group toxins in the starting material, we found that two proteins varied as a function of OA contamination. By BLAST analysis, the two proteins were identified as a component of photosystem II and a subunit of NADH dehydrogenase. The analysis of peptide homologies showed that the peptide of photosystem II we detected in extracts from the DG of mussels contaminated by OA-group toxins is identical to its counterpart in Dinophysis algae, which are the producers of this group of toxins. We concluded that proteomic analysis can be used for the detection and identification of biomarkers of biotoxin contamination in shellfish, including both proteins expressed by the toxin producers and components that participate to the tissue response to the exogenous bioactive contaminant. PMID:18782583

  8. Detection of enteric viruses in shellfish from the Norwegian coast.

    PubMed

    Myrmel, M; Berg, E M M; Rimstad, E; Grinde, B

    2004-05-01

    Common blue mussels (Mytilus edulis), horse mussels (Modiolus modiolus), and flat oysters (Ostrea edulis) obtained from various harvesting and commercial production sites along the Norwegian coast were screened for the presence of norovirus by a real-time reverse transcription (RT)-nested PCR assay and for possible indicators of fecal contamination, i.e., for F-specific RNA bacteriophages (F-RNA phages) by plaque assay and for human adenoviruses and human circoviruses by nested PCR assay. The aims were to obtain relevant information for assessing the risk of transmission of enteric viruses by shellfish and to investigate the potential of various indicator viruses in routine screening. Noroviruses were detected in 6.8% of the samples, and the indicators were detected in 23.8% (F-RNA phages), 18.6% (adenoviruses), and 8.0% (circoviruses) of the samples. A seasonal variation was observed, with the exception of circoviruses, with more positive samples in the winter. A positive correlation was found between F-RNA phages and noroviruses. However, F-RNA phages were present in only 43% of the norovirus-positive samples. The results show that mussels from the Norwegian coast can constitute a risk of infection with enteric viruses and that routine testing of samples may be justified. Advantages and disadvantages of various options for screening are discussed. PMID:15128518

  9. Studies on Freezint of Shell-Fish -II

    NASA Astrophysics Data System (ADS)

    Song, Dae Jin; Konagaya, Shiro; Nakamura, Koji; Iida, Haruka; Tanaka, Takeo

    Changes in free amino acid content and compostion, and formation of odor components in ark shell Anadara broughtonii(Shrenk) during frozen storgae were studied in connection with storage temperature. The shucked shell-fish were frozen -40C and stored at -10, -20 and -40C, respectively for three months, and the shell flesh were subjected to anyalyses for free amino acids and odor components. The amount of total free amino acids in the shell flesh storedat -10C was not as large as those in the flesh stored at -20 and -40C. This finding implies that free amino acids in the shell flesh, when frozen-stored at a relatively high temperature, decrease in amount during storage and/or become liable to be lost along with drip during the course of thawing. As for respective amino acids, a mounts of Tau, ?-Ala, and Gly decreased markedly, while those of Met, Leu and Ile increased to some extent. In addition, it is of particular interest that ?-Ala is likely to be present in the free state. Amounts of volatile compounds such as carbonyl, nitrogenous, and sulfurous compounds have never attained the level where unpleasant or fishy odor could be percieved. However, there was a clear tendency that the higher the storage temperature, the larger amount of these compounds were presen.

  10. Paralytic shellfish toxins inhibit copper uptake in Chlamydomonas reinhardtii.

    PubMed

    Cusick, Kathleen D; Wetzel, Randall K; Minkin, Steven C; Dodani, Sheel C; Wilhelm, Steven W; Sayler, Gary S

    2013-06-01

    Paralytic shellfish toxins are secondary metabolites produced by several species of dinoflagellates and cyanobacteria. Known targets of these toxins, which typically occur at detrimental concentrations during harmful algal blooms, include voltage-gated ion channels in humans and other mammals. However, the effects of the toxins on the co-occurring phytoplankton community remain unknown. The present study examined the molecular mechanisms of the model photosynthetic alga Chlamydomonas reinhardtii in response to saxitoxin exposure as a means of gaining insight into the phytoplankton community response to a bloom. Previous work with yeast indicated that saxitoxin inhibited copper uptake, so experiments were designed to examine whether saxitoxin exhibited a similar mode of action in algae. Expression profiling following exposure to saxitoxin or a copper chelator produced similar profiles in copper homeostasis genes, notably induction of the cytochrome c6 (CYC6) and copper transporter (COPT1, CTR1) genes. Cytochrome c6 is used as an alternative to plastocyanin under conditions of copper deficiency, and immunofluorescence data showed this protein to be present in a significantly greater proportion of saxitoxin-exposed cells compared to controls. Live-cell imaging with a copper-sensor probe for intracellular labile Cu(I) confirmed that saxitoxin blocked copper uptake. Extrapolations of these data to phytoplankton metabolic processes along with the copper transporter as a molecular target of saxitoxin based on existing structural models are discussed. PMID:23423950

  11. Removal of paralytic shellfish toxins by probiotic lactic acid bacteria.

    PubMed

    Vasama, Mari; Kumar, Himanshu; Salminen, Seppo; Haskard, Carolyn A

    2014-01-01

    Paralytic shellfish toxins (PSTs) are non-protein neurotoxins produced by saltwater dinoflagellates and freshwater cyanobacteria. The ability of Lactobacillus rhamnosus strains GG and LC-705 (in viable and non-viable forms) to remove PSTs (saxitoxin (STX), neosaxitoxin (neoSTX), gonyautoxins 2 and 3 (GTX2/3), C-toxins 1 and 2 (C1/2)) from neutral and acidic solution (pH 7.3 and 2) was examined using HPLC. Binding decreased in the order of STX ~ neoSTX > C2 > GTX3 > GTX2 > C1. Removal of STX and neoSTX (77%-97.2%) was significantly greater than removal of GTX3 and C2 (33.3%-49.7%). There were no significant differences in toxin removal capacity between viable and non-viable forms of lactobacilli, which suggested that binding rather than metabolism is the mechanism of the removal of toxins. In general, binding was not affected by the presence of other organic molecules in solution. Importantly, this is the first study to demonstrate the ability of specific probiotic lactic bacteria to remove PSTs, particularly the most toxic PST-STX, from solution. Further, these results warrant thorough screening and assessment of safe and beneficial microbes for their usefulness in the seafood and water industries and their effectiveness in vivo. PMID:25046082

  12. Interannual variability in the timing of New England shellfish toxicity and relationships to environmental forcing

    PubMed Central

    Nair, Apurva; Thomas, Andrew C.; Borsuk, Mark E.

    2013-01-01

    Routine monitoring along the coast of the Gulf of Maine (GoM) reveals shellfish toxicity nearly every summer, but at varying times, locations, and magnitudes. The responsible toxin is known to be produced by the dinoflagellate Alexandrium fundyense, yet there is little apparent association between Alexandrium abundance and shellfish toxicity. One possibility is that toxic cells are persistent in offshore areas and variability in shellfish toxicity is caused not by changes in overall abundance, but rather by variability in transport processes. Measurements of offshore Alexandrium biomass are scarce, so we bypass cell abundance as an explanatory variable and focus instead on the relations between shellfish toxicity and concurrent metrics of GoM meteorology, hydrology, and oceanography. While this yields over two decades (1985–2005) of data representing a variety of interannual conditions, the toxicity data are gappy in spatial and temporal coverage. We address this through a combination of parametric curve fitting and hierarchical cluster analysis to reveal eight archetypical modes of seasonal toxicity timing. Groups of locations are then formed that have similar interannual patterns in these archetypes. Finally, the interannual patterns within each group are related to available environmental metrics using classification trees. Results indicate that a weak cross-shore sea surface temperature (SST) gradient in the summer is the strongest correlate of shellfish toxicity, likely by signifying a hydrological connection between offshore Alexandrium populations and near-shore shellfish beds. High cumulative downwelling wind strength early in the season is revealed as a precursor consistent with this mechanism. Although previous studies suggest that alongshore transport is important in moving Alexandrium from the eastern to western GoM, alongshore SST gradient is not an important correlate of toxicity in our study. We conclude by discussing the implications of our results for designing efficient and effective shellfish monitoring programs along the GoM coast. PMID:23391892

  13. Seasonality of diarrhetic shellfish poisoning at a coastal lagoon in Portugal: rainfall patterns and folk wisdom.

    PubMed

    Vale, Paulo; Sampayo, Maria Antónia de M

    2003-02-01

    Of the three types of toxicity known so far in Portuguese shellfish, only diarrhetic shellfish poisoning (DSP) and amnesic shellfish poisoning (ASP) are produced by microalgae that seem to have been present in the last decades or centuries. The most important paralytic shellfish poisoning (PSP) producer, Gymnodinium catenatum, is hypothesised to have been introduced quite recently as only in 1976 PSP toxicity was detected for the first time in shellfish from Galicia, NW Iberian Peninsula. While ASP presents very short episodes of contamination, the concentration of DSP toxins in some years surpasses human safety values for much longer periods. It is traditionally stated that shellfish should be consumed in 'months with R' (September-April). A retrospective study of the maximum monthly DSP levels attained in mussels from a coastal lagoon-Ria de Aveiro-between 1994 and 2001, showed that the highest frequency of months with concentrations surpassing the safety level of 2 microg/g digestive glands were found in June-September, followed by May and October. These months correspond with the months of lowest historical average rainfall in the period 1941-1998. Oscillations in the rainfall pattern coincided with earliest (or latest) detection by HPLC of DSP toxins in mussel in the years studied. In a semi-closed lagunar environment prone to in situ growth of DSP-producer microalgae, like Dinophysis acuminata, rainfall affects river output, lowering salinity and disrupting water column stability that favours Dinophysis growth. The seasonality of DSP recurrence may be connected to the folk adage on safety of shellfish consumption, after many years of empirical observations by coastal populations of diarrhoea episodes in summertime. PMID:12565738

  14. Development and Validation of a Novel Lateral Flow Immunoassay (LFIA) for the Rapid Screening of Paralytic Shellfish Toxins (PSTs) from Shellfish Extracts.

    PubMed

    Jawaid, Waqass; Campbell, Katrina; Melville, Karrie; Holmes, Stephen J; Rice, Jennifer; Elliott, Christopher T

    2015-05-19

    A single-step lateral flow immunoassay (LFIA) was developed and validated for the rapid screening of paralytic shellfish toxins (PSTs) from a variety of shellfish species, at concentrations relevant to regulatory limits of 800 ?g STX-diHCl equivalents/kg shellfish meat. A simple aqueous extraction protocol was performed within several minutes from sample homogenate. The qualitative result was generated after a 5 min run time using a portable reader which removed subjectivity from data interpretation. The test was designed to generate noncompliant results with samples containing approximately 800 ?g of STX-diHCl/kg. The cross-reactivities in relation to STX, expressed as mean SD, were as follows: NEO: 128.9% 29%; GTX1&4: 5.7% 1.5%; GTX2&3: 23.4% 10.4%; dcSTX: 55.6% 10.9%; dcNEO: 28.0% 8.9%; dcGTX2&3: 8.3% 2.7%; C1&C2: 3.1% 1.2%; GTX5: 23.3% 14.4% (n = 5 LFIA lots). There were no indications of matrix effects from the different samples evaluated (mussels, scallops, oysters, clams, cockles) nor interference from other shellfish toxins (domoic acid, okadaic acid group). Naturally contaminated sample evaluations showed no false negative results were generated from a variety of different samples and profiles (n = 23), in comparison to reference methods (MBA method 959.08, LC-FD method 2005.06). External laboratory evaluations of naturally contaminated samples (n = 39) indicated good correlation with reference methods (MBA, LC-FD). This is the first LFIA which has been shown, through rigorous validation, to have the ability to detect most major PSTs in a reliable manner and will be a huge benefit to both industry and regulators, who need to perform rapid and reliable testing to ensure shellfish are safe to eat. PMID:25893460

  15. Studies on heat inactivation of hepatitis A virus with special reference to shellfish

    PubMed Central

    Millard, Judith; Appleton, Hazel; Parry, J. V.

    1987-01-01

    The consumption of bi-valve molluscan shellfish has been associated with outbreaks of viral gastroenteritis and hepatitis A. Investigations were undertaken to determine the heat inactivation conditions necessary to render shellfish such as cockles safe for the consumer. Conditions for the laboratory maintenance of live cockles are described. In preliminary experiments either poliovirus (106 TCID50/ml seawater) or hepatitis A virus (HAV) (approx. 104 RFU/ml seawater) was introduced into the shellfish tank. Following 48 h filter feeding, virus was recovered from cockles using an adsorption-elution extraction procedure. Titres of virus recovered ranged from 104 to 105 TCID50/ml of shellfish extract for poliovirus and from 103 to 105 RFU/ml of shellfish extract for HAV. Active ingestion of the virus from the seawater was demonstrated by recovering virus from within cockle guts. To quantify recovered HAV, end-point dilutions and an adaptation of a radioimmunofocus assay (RIFA) were compared. The tests were of similar sensitivity but the RIFA has the advantage of being relatively rapid, shortening the time taken to complete an experiment by as much as 4 weeks. ImagesFig. 3Fig. 2 PMID:3036554

  16. Management of domoic acid monitoring in shellfish from the Catalan coast.

    PubMed

    Gimnez Papiol, Gemma; Casanova, Alexis; Fernndez-Tejedor, Margarita; de la Iglesia, Pablo; Diogne, Jorge

    2013-08-01

    Monitoring of amnesic shellfish poisoning (ASP) toxins in shellfish from the Catalan coast started in 2001. No ASP toxins were detected in any of the analyses performed before 2008. On 22 January 2008, domoic acid (DA) was detected in Donax trunculus (0.5mg?kg(-1)) and confirmed by rapid resolution liquid chromatography-tandem mass spectrometry (0.6mg?kg(-1)). A total of 974 shellfish samples were analyzed from January 2008 to December 2011, covering all the Catalan production areas and the most important marketed species. DA was detected in 23.8% of the samples and was recorded every month in all areas and all species, except Ostrea edulis, although the percentage of samples with DA and DA content varied widely among samples. DA exceeded the regulatory level of 20mg?kg(-1) twice: in Callista chione sampled on February 2008 and in D. trunculus sampled on April 2010. DA content in Bolinus brandaris appeared constant and close to 4.5mg?kg(-1) for months in 2009. Mytilus galloprovincialis, Crassostrea gigas, and Ruditapes sp. presented very low concentrations of DA in the Ebro Delta bays, despite 113 alert situations according to Pseudo-nitzschia spp. abundances and the high number of shellfish samples analyzed. The origin of DA in Catalan shellfish remains unknown. PMID:23275095

  17. Occurrence and profiles of lipophilic toxins in shellfish harvested from Argentina.

    PubMed

    Turner, Andrew D; Goya, Alejandra B

    2015-08-01

    The presence of phytoplankton responsible for the production of lipophilic marine biotoxins is well recognised throughout parts of South America. To date, the quantitation of lipophilic toxins in Argentinean shellfish has been limited to select and highly focussed geographical studies. This work reports the analysis for lipophilic marine biotoxins in shellfish harvested across five regions of Argentina between 1992 and 2012. LC-MS/MS analysis was used for the quantitation of all regulated lipophilic toxins. High concentrations of okadaic acid group toxins were quantified, with a clear dominance of the parent okadaic acid and more than 90% of the toxin present as esters. Results showed DSP toxins in shellfish from the Buenos Aires Province during 2006 and 2007, earlier than previously described. There was also strong evidence linking the presence of okadaic acid to human intoxications. Other lipophilic toxins detected were yessotoxin, pectenotoxin-2 and 13-desMeC spirolide. With evidence published recently for the presence of azaspiracid producers, this work reports the detection of low concentrations of azaspiracid-2 in shellfish. As such the data provides the first published evidence for yessotoxins and azaspiracids in Argentinean shellfish and further evidence for the continuing presence of lipophilic marine toxins in Argentinean waters. PMID:26003796

  18. Exxon Valdez oil spill. State/federal natural resource damage assessment final report. Impacts of the Exxon Valdez oil spill on bottomfish and shellfish in Prince William Sound. Fish/shellfish study 18

    SciTech Connect

    1995-05-01

    Trawl surveys were conducted in Prince William Sound and adjacent waters in 1989 and 1990 to assess impacts of the Exxon Valdex oil spill on commercial species of bottomfish and shellfish. The surveys (1) determined abundance, distribution, and year-class strength of important bottomfish and shellfish species and (2) assessed the incidence and distribution of oil contamination in fish bile.

  19. Probiotics in fish and shellfish culture: immunomodulatory and ecophysiological responses.

    PubMed

    C De, Bidhan; Meena, D K; Behera, B K; Das, Pronob; Das Mohapatra, P K; Sharma, A P

    2014-06-01

    Aquaculture is emerging as one of the most viable and promising enterprises for keeping pace with the surging need for animal protein, providing nutritional and food security to humans, particularly those residing in regions where livestock is relatively scarce. With every step toward intensification of aquaculture practices, there is an increase in the stress level in the animal as well as the environment. Hence, disease outbreak is being increasingly recognized as one of the most important constraints to aquaculture production in many countries, including India. Conventionally, the disease control in aquaculture has relied on the use of chemical compounds and antibiotics. The development of non-antibiotic and environmentally friendly agents is one of the key factors for health management in aquaculture. Consequently, with the emerging need for environmentally friendly aquaculture, the use of alternatives to antibiotic growth promoters in fish nutrition is now widely accepted. In recent years, probiotics have taken center stage and are being used as an unconventional approach that has numerous beneficial effects in fish and shellfish culture: improved activity of gastrointestinal microbiota and enhanced immune status, disease resistance, survival, feed utilization and growth performance. As natural products, probiotics have much potential to increase the efficiency and sustainability of aquaculture production. Therefore, comprehensive research to fully characterize the intestinal microbiota of prominent fish species, mechanisms of action of probiotics and their effects on the intestinal ecosystem, immunity, fish health and performance is reasonable. This review highlights the classifications and applications of probiotics in aquaculture. The review also summarizes the advancement and research highlights of the probiotic status and mode of action, which are of great significance from an ecofriendly, sustainable, intensive aquaculture point of view. PMID:24419543

  20. Prevalence and Characterization of Shiga Toxin-Producing and Enteropathogenic Escherichia coli in Shellfish-Harvesting Areas and Their Watersheds

    PubMed Central

    Balière, Charlotte; Rincé, Alain; Blanco, Jorge; Dahbi, Ghizlane; Harel, Josée; Vogeleer, Philippe; Giard, Jean-Christophe; Mariani-Kurkdjian, Patricia; Gourmelon, Michèle

    2015-01-01

    more strains formed a strong biofilm at 18 than at 30°C. Finally, more than 85% of analyzed strains were found to be sensitive to the 16 tested antibiotics. These data suggest the low risk of human infection by STEC if shellfish from these shellfish-harvesting areas were consumed. PMID:26648928

  1. A competitive ELISA to detect brevetoxins from Karenia brevis (formerly Gymnodinium breve) in seawater, shellfish, and mammalian body fluid.

    PubMed Central

    Naar, Jerome; Bourdelais, Andrea; Tomas, Carmelo; Kubanek, Julia; Whitney, Philip L; Flewelling, Leanne; Steidinger, Karen; Lancaster, Johnny; Baden, Daniel G

    2002-01-01

    We developed a competitive enzyme-linked immunosorbent assay (ELISA) to analyze brevetoxins, using goat anti-brevetoxin antibodies obtained after immunization with keyhole limpet hemocyanin-brevetoxin conjugates, in combination with a three-step signal amplification process. The procedure, which used secondary biotinylated antibodies, streptavidine-horseradish peroxidase conjugate, and chromogenic enzyme substrate, was useful in reducing nonspecific background signals commonly observed with complex matrices. This competitive ELISA detected brevetoxins in seawater, shellfish extract and homogenate, and mammalian body fluid such as urine and serum without pretreatment, dilution, or purification. We investigated the application of this technique for shellfish monitoring by spiking shellfish meat with brevetoxins and by analyzing oysters from two commercial shellfish beds in Florida that were exposed to a bloom of Karenia brevis (formerly Gymnodinium breve). We performed brevetoxin analysis of shellfish extracts and homogenates by ELISA and compared it with the mouse bioassay and receptor binding assay. The detection limit for brevetoxins in spiked oysters was 2.5 microg/100 g shellfish meat. This assay appears to be a useful tool for neurotoxic shellfish poisoning monitoring in shellfish and seawater, and for mammalian exposure diagnostics, and significantly reduces the time required for analyses. PMID:11836147

  2. Formation of a Volunteer Harmful Algal Bloom Network in British Columbia, Canada, Following an Outbreak of Diarrhetic Shellfish Poisoning

    PubMed Central

    McIntyre, Lorraine; Cassis, David; Haigh, Nicola

    2013-01-01

    Evidence for shellfish toxin illness in British Columbia (BC) on the west coast of Canada can be traced back to 1793. For over two hundred years, domestically acquired bivalve shellfish toxin illnesses in BC were solely ascribed to paralytic shellfish poisonings caused by algal blooms of Alexandrium. This changed in 2011, when BC experienced its first outbreak of diarrhetic shellfish poisoning (DSP). As a result of this outbreak, Canada’s first DSP symposium was held in November, 2012, in North Vancouver, BC. Three of the objectives of the symposium were to provide a forum to educate key stakeholders on this emerging issue, to identify research and surveillance priorities and to create a DSP network. The purpose of this paper is to review what is known about shellfish poisoning in BC and to describe a novel volunteer network that arose following the symposium. The newly formed network was designed for industry shellfish growers to identify harmful algae bloom events, so that they may take actions to mitigate the effects of harmful blooms on shellfish morbidity. The network will also inform public health and regulatory stakeholders of potentially emerging issues in shellfish growing areas. PMID:24172211

  3. Relating the bivalve shellfish harvesting area classification criteria in the United States and European Union programmes.

    PubMed

    Lee, R J; Reese, R A

    2014-06-01

    Estimation of the level of risk of faecal contamination of shellfish harvesting areas is undertaken by monitoring faecal indicator bacteria in seawater samples under the United States programme and shellfish flesh samples under the European Union (EU) programme. Determining the relationship between the two approaches is important for assessing the relative level of public health protection and regulating international trade. The relationship was investigated using both statistical modelling and simple compliance assessment on large international data sets of paired seawater and shellfish samples. The two approaches yielded the same conclusions: EU class A is more stringent than the US Approved category for all species; the US Restrictive standard is more restrictive than EU class B for some bivalve species. Therefore, the classifications under the two programmes are not exactly equivalent. PMID:24937222

  4. Effect of the Clean Water Act on shellfish growing waters in the Gulf of Mexico

    SciTech Connect

    Broutman, M.A.

    1988-01-01

    This report examines the classification of shellfish growing waters in the Gulf of Mexico as an indicator of bacterial water quality. Information presented includes the status of classified waters, sources of pollution affecting waters that are not classified as approved, and trends in classification between 1971 and 1985. Data were collected by site visits to the five Gulf states, interviews with state personnel, and reference to written materials. Data are used to assess the effectiveness of national efforts to improve bacterial water quality in the past fifteen years since passage of the Clean Water Act. The hypothesis to be tested is that these efforts have not succeeded in reducing fecal coliform concentrations to levels required for approved harvest of shellfish, as established by the National Shellfish Sanitation Program.

  5. Recent innovation in microbial source tracking using bacterial real-time PCR markers in shellfish.

    PubMed

    Mauffret, A; Mieszkin, S; Morizur, M; Alfiansah, Y; Lozach, S; Gourmelon, M

    2013-03-15

    We assessed the capacity of real-time PCR markers to identify the origin of contamination in shellfish. Oyster, cockles or clams were either contaminated with fecal materials and host-associated markers designed from Bacteroidales or Catellicoccus marimammalium 16S RNA genes were extracted from their intravalvular liquid, digestive tissues or shellfish flesh. Extraction of bacterial DNA from the oyster intravalvular liquid with FastDNA spin kit for soil enabled the selected markers to be quantified in 100% of artificially contaminated samples, and the source of contamination to be identified in 13 out of 38 naturally contaminated batches from European Class B and Class C areas. However, this protocol did not enable the origin of the contamination to be identified in cockle or clam samples. Although results are promising for extracts from intravalvular liquid in oyster, it is unlikely that a single protocol could be the best across all bacterial markers and types of shellfish. PMID:23398745

  6. Mining marine shellfish wastes for bioactive molecules: chitin and chitosan--Part A: extraction methods.

    PubMed

    Hayes, Maria; Carney, Brian; Slater, John; Brck, Wolfram

    2008-07-01

    Legal restrictions, high costs and environmental problems regarding the disposal of marine processing wastes have led to amplified interest in biotechnology research concerning the identification and extraction of additional high grade, low-volume by-products produced from shellfish waste treatments. Shellfish waste consisting of crustacean exoskeletons is currently the main source of biomass for chitin production. Chitin is a polysaccharide composed of N-acetyl-D-glucosamine units and the multidimensional utilization of chitin derivatives including chitosan, a deacetylated derivative of chitin, is due to a number of characteristics including: their polyelectrolyte and cationic nature, the presence of reactive groups, high adsorption capacities, bacteriostatic and fungistatic influences, making them very versatile biomolecules. Part A of this review aims to consolidate useful information concerning the methods used to extract and characterize chitin, chitosan and glucosamine obtained through industrial, microbial and enzymatic hydrolysis of shellfish waste. PMID:18320562

  7. Relationship among fecal coliforms, Escherichia coli, and Salmonella spp. in shellfish.

    PubMed Central

    Hood, M A; Ness, G E; Blake, N J

    1983-01-01

    The relationship of fecal coliforms, Escherichia coli, and Salmonella spp. was examined in freshly harvested and stored shellfish. In 16 of 40 freshly collected oyster samples, fecal coliform levels were above the recommended wholesale level suggested by the National Shellfish Sanitation Program (less than or equal to 230/100 g), and Salmonella spp. were present in three of these samples. Salmonella spp. were not, however, present in any sample containing less than 230 fecal coliforms per 100 g. Analysis of the data suggests that low fecal coliform levels in both fresh and stored oysters are good indicators of the absence of Salmonella spp., but that high levels of fecal coliforms are somewhat limited in predicting the presence of Salmonella spp. E. coli levels correlated very strongly with fecal coliform levels in both fresh and stored oysters and clams, suggesting that there is no advantage in replacing fecal coliforms with E. coli as an indicator of shellfish quality. PMID:6337547

  8. Characterization of phospholipid molecular species in the edible parts of bony fish and shellfish.

    PubMed

    Boselli, Emanuele; Pacetti, Deborah; Lucci, Paolo; Frega, Natale G

    2012-03-28

    The phospholipid molecular species of freshwater (pangasius, Nile perch, trout), marine fish fillets (horse mackerel, European hake, common sole, European anchovy, European pilchard, Atlantic mackerel) and the edible muscle foot of bivalves (clam, mussel, oyster) commonly available in the Italian market during spring and summer were characterized by means of normal-phase high performance liquid chromatography coupled online with positive electrospray ionization ion-trap tandem mass spectrometry. From principal component analysis (PCA), it was observed that the total fatty acid profile was not suitable to differentiate among the shellfish genera. The fatty acid molecular combinations of phosphatidylcholine, the main phospholipid class, as well as phosphatidylinositol and phosphatidylethanolamine allowed for the differentiation of shellfish from the bony fishes. Phosphatidylserine and phosphatidylethanolamine plasmalogen profile allowed for the discrimination of each bony fish or shellfish genus since PS and pPE classes included a large number of fatty acid combinations that were specific for a fish genus or group. PMID:22369175

  9. National estuarine inventory: Classified shellfish growing waters by estuary. Final report

    SciTech Connect

    Broutman, M.A.; Leonard, D.L.

    1986-12-01

    The report is the first in a series of reports that compile information on classified shellfish waters as an indicator of coliform bacteria pollution in the Nation's estuaries. Data for the report have been derived from the 1985 National Shellfish Register. Although the Register has provided consistent data on acreage of classified shellfish waters by state, use of it as a national water-quality indicator has been hindered because of the influence of factors other than water quality on classification. The report improves the 1985 Register data by: (1) reorganizing data into 92 estuaries on the East, West, and Gulf coasts that comprise the National Estuarine Inventory, and (2) correcting data for areas that were classified for reasons other than water quality.

  10. Evidence of paralytic shellfish poisoning toxin in milkfish in South Taiwan.

    PubMed

    Chou, H-N; Chung, Y-C; Cho, W-C; Chen, C-Y

    2003-06-01

    Natural phytoplankton blooms of the dinoflagellate Alexandrium minutum, milkfish (Chanos chanos) exposed to natural blooms, sediment and mangrove crab (Scylla serrata) were analysed for paralytic shellfish poisoning toxins by high-performance liquid chromatography. The toxin profiles of milkfish and mangrove crab were similar to that of A. minutum collected from blooming fishponds. In a laboratory A. minutum-blooming environment, the stomach and intestine of milkfish accumulated paralytic shellfish poisoning toxins during the exposure period. The non-visceral tissues were non-toxic. However, milkfish lost their entire body burden of toxin on the first day of transferring to a toxic algae-free environment. The result shows that milkfish concentrate paralytic shellfish poisoning toxins in digestive organs and did not retain toxins. PMID:12881129

  11. Warm temperature acclimation impacts metabolism of paralytic shellfish toxins from Alexandrium minutum in commercial oysters.

    PubMed

    Farrell, Hazel; Seebacher, Frank; O'Connor, Wayne; Zammit, Anthony; Harwood, D Tim; Murray, Shauna

    2015-09-01

    Species of Alexandrium produce potent neurotoxins termed paralytic shellfish toxins and are expanding their ranges worldwide, concurrent with increases in sea surface temperature. The metabolism of molluscs is temperature dependent, and increases in ocean temperature may influence both the abundance and distribution of Alexandrium and the dynamics of toxin uptake and depuration in shellfish. Here, we conducted a large-scale study of the effect of temperature on the uptake and depuration of paralytic shellfish toxins in three commercial oysters (Saccostrea glomerata and diploid and triploid Crassostrea gigas, n=252 per species/ploidy level). Oysters were acclimated to two constant temperatures, reflecting current and predicted climate scenarios (22 and 27C), and fed a diet including the paralytic shellfish toxin-producing species Alexandrium minutum. While the oysters fed on A. minutum in similar quantities, concentrations of the toxin analogue GTX1,4 were significantly lower in warm-acclimated S. glomerata and diploid C. gigas after 12days. Following exposure to A. minutum, toxicity of triploid C. gigas was not affected by temperature. Generally, detoxification rates were reduced in warm-acclimated oysters. The routine metabolism of the oysters was not affected by the toxins, but a significant effect was found at a cellular level in diploid C. gigas. The increasing incidences of Alexandrium blooms worldwide are a challenge for shellfish food safety regulation. Our findings indicate that rising ocean temperatures may reduce paralytic shellfish toxin accumulation in two of the three oyster types; however, they may persist for longer periods in oyster tissue. PMID:26032975

  12. Shellfish and residual chemical contaminants: hazards, monitoring, and health risk assessment along French coasts.

    PubMed

    Guéguen, Marielle; Amiard, Jean-Claude; Arnich, Nathalie; Badot, Pierre-Marie; Claisse, Didier; Guérin, Thierry; Vernoux, Jean-Paul

    2011-01-01

    In this review, we address the identification of residual chemical hazards in shellfish collected from the marine environment or in marketed shellfish. Data, assembled on the concentration of contaminants detected, were compared with the appropriate regulatory and food safety standards. Moreover, data on human exposure and body burden levels were evaluated in the context of potential health risks.Shellfish farming is a common industry along European coasts. The primary types of shellfish consumed in France are oysters, mussels, king scallops, winkles,whelks, cockles, clams, and other scallops. Shellfish filter large volumes of water to extract their food and are excellent bioaccumulators. Metals and other pollutants that exist in the marine environment partition into particular organs, according to their individual chemical characteristics. In shellfish, accumulation often occurs in the digestive gland, which plays a role in assimilation, excretion, and detoxification of contaminants. The concentrations of chemical contaminants in bivalve mollusks are known to fluctuate with the seasons.European regulations limit the amount and type of contaminants that can appear in foodstuffs. Current European standards regulate the levels of micro-biological agents, phycotoxins, and some chemical contaminants in food. Since 2006, these regulations have been compiled into the "Hygiene Package." Bivalve mollusks must comply with maximum levels of certain contaminants as follows:lead (1.5 mg kg-1), cadmium (1 mg kg-1), mercury (0.5 mg kg-1), dioxins (4 pg g-1 and dioxins + DL-PCBs 8 pg g-1), and benzo[a]pyrene (10 μp.g kg-1).In this review, we identify the levels of major contaminants that exist in shellfish(collected from the marine environment and/or in marketed shellfish). The follow-ing contaminants are among those that are profiled: Cd, Pb, Hg, As, Ni, Cr, V,Mn, Cu, Zn, Co, Se, Mg, Mo, radionuclides, benzo[a]pyrene, PCBs, dioxins and furans, PAHs, TBT, HCB, dieldrin, DDT, lindane, triazines, PBDE, and chlorinated paraffins.In France, the results of contaminant monitoring have indicated that Cd, but not lead (< 0.26 mg kg-1) or mercury (< 0.003 mg kg-1), has had some non-compliances. Detections for PCBs and dioxins in shellfish were far below the regulatory thresholds in oysters (< 0.6 pg g-l), mussels (< 0.6 pg g-1), and king scallops (< 0.4 pg g-1). The benzo[a]pyrene concentration in marketed mussels and farmed shellfish does not exceed the regulatory threshold. Some monitoring data are available on shellfish flesh contamination for unregulated organic contaminants.Of about 100 existing organo stannic compounds, residues of the mono-, di-, and tributyltin (MBT, DBT, and TBT) and mono-, di-, and triphenyltin (MPT, DPT,and TPT) compounds are the most frequently detected in fishery products. Octyltins are not found in fishery products. Some bivalve mollusks show arsenic levels up to 15.8 mg kg-1. It seems that the levels of arsenic in the environment derive less from bioaccumulation, than from whether the arsenic is in an organic or an inorganic form. In regard to the other metals, levels of zinc and magnesium are higher in oysters than in mussels.To protect shellfish from chemical contamination, programs have been established to monitor water masses along coastal areas. The French monitoring network(ROCCH) focuses on environmental matrices that accumulate contaminants. These include both biota and sediment. Example contaminants were studied in a French coastal lagoon (Arcachon Bay) and in an estuary (Bay of Seine), and these were used to illustrate the usefulness of the monitoring programs. Twenty-one pesticidal and biocidal active substances were detected in the waters of Arcachon Bay during the summers from 1999 to 2003, at concentrations ranging from a few nanograms per liter to several hundred nanograms per liter. Most of the detected substances were herbicides, including some that are now banned. Organotin compounds have been detected in similarly semi-enclosed waters elsewhere (bays, estuaries, and harbors).However, the mean concentrations of cadmium, mercury, lead, and benzo[a]pyrene,in transplanted mussels, were below the regulatory limits.In 2007, the mean daily consumption of shellfish in the general French population was estimated to be 4.5 g in adults; however, a wide variation occurs by region and season (INCA 2 study). Tabulated as a proportion of the diet, shellfish consumption represents only 0.16% of overall solid food intake. However, the INCA 2 survey was not well suited to estimating shellfish consumption because of the small number of shellfish consumers sampled. In contrast, the mean consumption rate of bivalve mollusks among adult high consumers of fish and seafood products, i.e., adults who eat fish or seafood at least twice a week, was estimated to be 153 g week-1 (8 kg yr-1). The highest mean consumption is for king scallops (39 g week-1), followed by oysters (34 g week-1) and mussels (22 g week-1). Thus, for high seafood consumers, the contribution of shellfish to inorganic contaminant levels is 1-10% TWI or PTWI for Cd, MeHg, and Sn (up to 19% for Sn), and the arsenic body burden is higher for 22% of individuals studied.The human health risks associated with consuming chemical contaminants in shellfish are difficult to assess for several reasons: effects may only surface after long-term exposure (chronic risk), exposures may be discontinuous, and contamination may derive from multiple sources (food, air, occupational exposure, etc.).Therefore, it is not possible to attribute a high body burden specifically to shellfish consumption even if seafood is a major dietary contributor of any contaminant, e.g.,arsenic and mercury.The data assembled in this review provide the arguments for maintaining the chemical contaminant monitoring programs for shellfish. Moreover, the results presented herein suggest that monitoring programs should be extended to other chemicals that are suspected of presenting a risk to consumers, as illustrated by the high concentration reported for arsenic (in urine) of high consumers of seafood products from the CALIPSO study. In addition, the research conducted in shellfish-farming areas of Arcachon Bay highlights the need to monitor TBT and PAH contamination levels to ensure that these chemical pollutants do not migrate from the harbor to oyster farms.Finally, we have concluded that shellfish contamination from seawater offers a rather low risk to the general French population, because shellfish do not constitute a major contributor to dietary exposure of chemical contaminants. Notwithstanding,consumer vigilance is necessary among regular shellfish consumers, and especially for those residing in fishing communities, for pregnant and breast-feeding women,and for very young children. PMID:21541848

  13. Isodomoic acid C, an unusual amnesic shellfish poisoning toxin from Pseudo-nitzschia australis.

    PubMed

    Holland, Patrick T; Selwood, Andrew I; Mountfort, Douglas O; Wilkins, Alistair L; McNabb, Paul; Rhodes, Lesley L; Doucette, Gregory J; Mikulski, Christina M; King, Kristen L

    2005-05-01

    An unusual isomer of domoic acid (1), isodomoic acid C (2), has been found in New Zealand shellfish contaminated by amnesic shellfish poisoning (ASP) toxins and was shown to be produced by a local strain of the pennate diatom Pseudo-nitzschia australis. A bulk culture of this strain was used to isolate 2. The structure was determined from spectroscopic data and was shown to correspond to that of 2 from a Japanese red seaweed, the only other reported occurrence of this compound. The affinity of 2 for GluR6 glutamate receptors was 240-fold lower than for 1, indicating low neurotoxic potential. PMID:15892574

  14. Outbreak of Diarrhetic Shellfish Poisoning Associated with Mussels, British Columbia, Canada

    PubMed Central

    Taylor, Marsha; McIntyre, Lorraine; Ritson, Mark; Stone, Jason; Bronson, Roni; Bitzikos, Olga; Rourke, Wade; Galanis, Eleni

    2013-01-01

    In 2011, a Diarrhetic Shellfish Poisoning (DSP) outbreak occurred in British Columbia (BC), Canada that was associated with cooked mussel consumption. This is the first reported DSP outbreak in BC. Investigation of ill individuals, traceback of product and laboratory testing for toxins were used in this investigation. Sixty-two illnesses were reported. Public health and food safety investigation identified a common food source and harvest area. Public health and regulatory agencies took actions to recall product and notify the public. Shellfish monitoring program changes were implemented after the outbreak. Improved response and understanding of toxin production will improve management of future DSP outbreaks. PMID:23697950

  15. Trace metal content of fish and shellfishes of the Niger delta area of Nigeria

    SciTech Connect

    Kakulu, S.E.; Osibanjo, O.; Ajayi, S.O.

    1987-01-01

    The trace metal contents of various fish and shellfishes from the Niger delta area of Nigeria were determined. The levels in the shellfishes were higher than those in the fish, which could be due to their being bottom feeders. The levels of fish varied from <0.01-0.10 ..mu..g/g for Cd, < 0.05-3.69 ..mu..g/g for Cu, 0.49-16.52 ..mu..g/g for Fe, and 0.08-6.90 ..mu..g/g for Zn. 15 references, 1 figures, 2 tables.

  16. Shellfish depuration by gamma irradiation. Progress report No. 1, October 1, 1985-July 25, 1986

    SciTech Connect

    Beghian, L.; Melnick, J.

    1986-07-25

    Objective is to investigate the feasibility of employing food irradiation technology to reduce or eliminate the threat of viral diseases contracted as a result of consumption of raw or inadequately cooked shellfish. Several recently published studies warn of the health risks associated with eating of raw shellfish - particularly American oysters, Crassostrea virginica, and the hardshelled clam, Mercenaria mercenaria. This study addresses the possibility of reducing the incidence of molluscanborne diseases through the application of /sup 60/Co gamma irradiation processing to effect the inactivation of pathogenic viruses in live, raw shwllfish. Dosimetry, D/sub 10/ doses, and organoleptic effects were studied.

  17. Shellfish allergy and relation to iodinated contrast media: United Kingdom survey

    PubMed Central

    Baig, Mudassar; Farag, Ahmad; Sajid, Jamal; Potluri, Rahul; Irwin, R Bruce; Khalid, Hafiz Mohammed Idrees

    2014-01-01

    AIM: To assess current practice of United Kingdom cardiologists with respect to patients with reported shellfish/iodine allergy, and in particular the use of iodinated contrast for elective coronary angiography. Moreover we have reviewed the current evidence-base and guidelines available in this area. METHODS: A questionnaire survey was send to 500 senior United Kingdom cardiologists (almost 50% cardiologists registered with British Cardiovascular Society) using email and first 100 responses used to analyze practise. We involved cardiologists performing coronary angiograms routinely both at secondary and tertiary centres. Three specific questions relating to allergy were asked: (1) History of shellfish/iodine allergy in pre-angiography assessment; (2) Treatments offered for shellfish/iodine allergy individuals; and (3) Any specific treatment protocol for shellfish/iodine allergy cases. We aimed to establish routine practice in United Kingdom for patients undergoing elective coronary angiography. We also performed comprehensive PubMed search for the available evidence of relationship between shellfish/iodine allergy and contrast media. RESULTS: A total of 100 responses were received, representing 20% of all United Kingdom cardiologists. Ninety-three replies were received from consultant cardiologists, 4 from non-consultant grades and 3 from cardiology specialist nurses. Amongst the respondents, 66% routinely asked about a previous history of shellfish/iodine allergy. Fifty-six percent would pre-treat these patients with steroids and anti-histamines. The other 44% do nothing, or do nonspecific testing based on their personal experience as following: (1) Skin test with 1 mL of subcutaneous contrast before intravenous contrast; (2) Test dose 2 mL contrast before coronary injection; (3) Close observation for shellfish allergy patients; and (4) Minimal evidence that the steroid and anti-histamine regime is effective but it makes us feel better. CONCLUSION: There is no evidence that allergy to shellfish alters the risk of reaction to intravenous contrast more than any other allergy and asking about such allergies in pre-angiogram assessment will not provide any additional information except propagating the myth. PMID:24669292

  18. TOXICITY ASSESSMENT OF PARALYTIC SHELLFISH POISONS (PSPS) USING QUANTITATIVE STRUCTURE-ACTIVITY RELATIONSHIPS

    EPA Science Inventory

    The most significant harmful algal bloom (HAB) toxin in terms of public health is commonly known as paralytic shellfish poisons (PSPs, "red tides" toxins). PSPs are neurotoxins produced by marine dinoflagellates and some cyanobacteria. PSPs comprise of over 21 natural toxins wi...

  19. Shellfish-associated enteric virus illness: virus localization, disease outbreaks and prevention

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerous outbreaks of shellfish-borne enteric virus illness have been reported worldwide. Most notable among the outbreaks are those involving norovirus illness and hepatitis A. Lessons learned from outbreak investigations indicate that most outbreaks are preventable. Anthropogenic sources of con...

  20. Complete genome sequence of the larval shellfish pathogen Vibrio Tubiashii type strain ATCC 19109

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vibrio tubiashii is a larval shellfish pathogen. Here we report the first closed genome sequence for this species (American Type Culture Collection type strain 19109), which has two chromosomes (3,294,490 and 1,766,582 bp), two megaplasmids (251,408 and 122,808 bp) and two plasmids (57,076 and 47,9...

  1. A functional assay for paralytic shellfish toxins that uses recombinant sodium channels.

    PubMed

    Vlez, P; Sierralta, J; Alcayaga, C; Fonseca, M; Loyola, H; Johns, D C; Tomaselli, G F; Marbn, E; Surez-Isla, B A

    2001-07-01

    Saxitoxin (STX) and its derivatives are highly toxic natural compounds produced by dinoflagellates commonly present in marine phytoplankton. During algal blooms ("red tides"), shellfish accumulate saxitoxins leading to paralytic shellfish poisoning (PSP) in human consumers. PSP is a consequence of the high-affinity block of voltage-dependent Na channels in neuronal and muscle cells. PSP poses a significant public health threat and an enormous economic challenge to the shellfish industry worldwide. The standard screening method for marine toxins is the mouse mortality bioassay that is ethically problematic, costly and time-consuming. We report here an alternative, functional assay based on electrical recordings in cultured cells stably expressing a PSP target molecule, the STX-sensitive skeletal muscle Na channel. STX-equivalent concentration in the extracts was calibrated by comparison with purified STX, yielding a highly significant correlation (R=0.95; N=30) between electrophysiological determinations and the values obtained by conventional methods. This simple, economical, and reproducible assay obviates the need to sacrifice millions of animals in mandatory paralytic shellfish toxin screening programs. PMID:11223080

  2. Occurrence of Lipophilic Marine Toxins in Shellfish from Galicia (NW of Spain) and Synergies among Them

    PubMed Central

    Rodríguez, Laura P.; González, Virginia; Martínez, Aníbal; Paz, Beatriz; Lago, Jorge; Cordeiro, Victoria; Blanco, Lucía; Vieites, Juan Manuel; Cabado, Ana G.

    2015-01-01

    Lipophilic marine toxins pose a serious threat for consumers and an enormous economic problem for shellfish producers. Synergistic interaction among toxins may play an important role in the toxicity of shellfish and consequently in human intoxications. In order to study the toxic profile of molluscs, sampled during toxic episodes occurring in different locations in Galicia in 2014, shellfish were analyzed by liquid chromatography tandem mass spectrometry (LC–MS/MS), the official method for the detection of lipophilic toxins. The performance of this procedure was demonstrated to be fit for purpose and was validated in house following European guidelines. The vast majority of toxins present in shellfish belonged to the okadaic acid (OA) group and some samples from a particular area contained yessotoxin (YTX). Since these toxins occur very often with other lipophilic toxins, we evaluated the potential interactions among them. A human neuroblastoma cell line was used to study the possible synergies of OA with other lipophilic toxins. Results show that combination of OA with dinophysistoxin 2 (DTX2) or YTX enhances the toxicity triggered by OA, decreasing cell viability and cell proliferation, depending on the toxin concentration and incubation time. The effects of other lipophilic toxins as 13-desmethyl Spirolide C were also evaluated in vitro. PMID:25815891

  3. High pressure processing as an intervention for raw virus-contaminated shellfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over the past 7 years, the USDA ARS Seafood Safety Laboratory has evaluated the potential use of high pressure processing (HPP) as a processing strategy for virus-contaminated shellfish. HPP can inactivate hepatitis A virus, (HAV), the human norovirus surrogates feline calicivirus and murine norovi...

  4. New perspectives on virus detection in shellfish: hemocytes as a source of concentrated virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    USDA ARS research indicates that circulating phagocytic cells (hemocytes) within oysters retain virus particles. We find that persistence of hepatitis A virus (HAV) within oyster hemocytes correlates with the presence of virus within whole oysters. Since bivalve shellfish have no self-nonself immun...

  5. MOLECULAR DETECTION AND HIGH PRESSURE SANITIZATION OF SHELLFISH-BORNE VIRUSES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A highly sensitive virus RNA extraction method for shellfish, using Glycine buffer, Polyethylene glycol, Tri-reagent and poly dT magnetic beads, termed the GPTT procedure, has recently been developed which facilitates RT-PCR detection of hepatitis A (HAV), hepatitis E (HEV), and Norwalk-like viruses...

  6. Metal Content in Four Shellfish Species from the Istrian Coast of Croatia.

    PubMed

    Bilandi?, Nina; Sedak, Marija; ?alopek, Bruno; Dafi?, Natalija; Ostoji?, Dijana Mieti?; Poto?njak, Dalibor

    2015-11-01

    The concentrations of As, Cd, Cu, Hg, Pb and Zn were measured in four shellfish species (oysters, mussels, scallops, warty venus) collected along the Istria Peninsula coast during autumn 2013. Mean metal levels in shellfish ranged as follows (mg/kg): As 1.69-3.91, Cd 0.15-0.99, Hg 0.06-0.2, Pb 0.33-0.74, Cu 1.23-36.2, Zn 16.3-511. Statistical analysis showed a significant difference in As (p<0.05), Cd, Pb, Hg, Cu and Zn (p<0.01, all) levels among shellfish species. The highest metal concentrations were found in oysters (mg/kg): As 3.91, Cd 0.99, Cu 36.2 and Zn 511. The highest means of Pb and Hg were measured in (mg/kg): warty venus 0.74; scallops 0.12. The estimated daily intakes for oysters shown it as a good source of Cu and Zn. The higher contribution of Cd and As levels to the provisional tolerable weekly intake in shellfishes suggest a careful approach for consumption. PMID:26210827

  7. MODELING FISH AND SHELLFISH DISTRIBUTIONS IN THE MOBILE BAY ESTUARY, USA

    EPA Science Inventory

    Estuaries in the Gulf of Mexico provide rich habitat for many fish and shellfish, including those that have been identified as economically and ecologically important. For the Mobile Bay estuary, we developed statistical models to relate distributions of individual species and sp...

  8. Determination of brevetoxins in shellfish by LC/MS/MS: single-laboratory validation.

    PubMed

    McNabb, Paul S; Selwood, Andrew I; Van Ginkel, Roel; Boundy, Michael; Holland, Patrick T

    2012-01-01

    A single-laboratory validation is reported for an LC/MS/MS quantification of six brevetoxins in four matrixes (Greenshell mussel, eastern oyster, hard clam, and Pacific oyster). Recovery and precision data were collected from seven analytical batches using shellfish flesh at 0.05 mg/kg. Method recoveries and within-laboratory reproducibility ranged from 73 to 112%, with an RSD between 14 and 18% for brevetoxin-3, brevetoxin B5, brevetoxin B2, and S-desoxy brevetoxin B2. The recovery and within-laboratory reproducibility for brevetoxin-2 was 61%, with an RSD of 27%. Brevetoxin B1 gave an RSD of 12%, but no reference material was available and this toxin was only recorded in a hard clam sample naturally contaminated with brevetoxins. One naturally contaminated sample of each shellfish matrix, with brevetoxin levels ranging from 0.012 to 9.9 mg/kg, was tested in multiple batches, and the RSDs were similar to those for fortified samples at 0.05 mg/kg. Comparisons with limited data for the neurotoxic shellfish poisoning mouse bioassay for four naturally contaminated shellfish samples showed that the regulatory action limit of 0.8 mg/kg is conservative with respect to the bioassay regulatory limit of 20 mouse units/100 g. PMID:22970578

  9. The quantitative bacteriology of some commercial bivalve shellfish entering British markets.

    PubMed Central

    Ayres, P. A.

    1975-01-01

    Incidents of non-specific illness associated with the consumption of oysters have highlighted the lack of published information on the bacteriology of shellfish suitable for consumption. Investigations showed that the majority of molluscan shellfish entering English markets conform to the accepted standard of less than 5 Escherichia coli/ml. tissue. The numbers of E. coli were related to the sanitary quality of the growing area but no relation could be established between numbers of E. coli and coliforms, faecal streptococci or Clostridium welchii. The numbers of non-specific bacteria varied considerably but shellfish from sources associated with non-specific illness yielded relatively high counts at 37 degrees C. The results showed that there was no justification for a standard based on total plate counts, which often exceeded 10(6)/g. Such a standard would have to be coupled with spoilage or the incidence of non-specific illness. The relation between the numbers of non-specific bacteria growing at 20 and 37 degrees C. appears to be a useful measure for assessing the likelihood that raw shellfish are a public health risk. PMID:168251

  10. Fluorogenic membrane overlays to enumerate total coliforms, Escherichia coli, and total Vibrionaceae in shellfish and seawater

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three assays were developed to enumerate total coliforms, Escherichia coli, and total Vibrionaceae in shellfish and other foods and in seawater and other environmental samples. Assays involve membrane overlays of overnight colonies on non-selective agar plates to detect ß-glucuronidase and lysyl am...

  11. Occurrence of lipophilic marine toxins in shellfish from Galicia (NW of Spain) and synergies among them.

    PubMed

    Rodrguez, Laura P; Gonzlez, Virginia; Martnez, Anbal; Paz, Beatriz; Lago, Jorge; Cordeiro, Victoria; Blanco, Luca; Vieites, Juan Manuel; Cabado, Ana G

    2015-04-01

    Lipophilic marine toxins pose a serious threat for consumers and an enormous economic problem for shellfish producers. Synergistic interaction among toxins may play an important role in the toxicity of shellfish and consequently in human intoxications. In order to study the toxic profile of molluscs, sampled during toxic episodes occurring in different locations in Galicia in 2014, shellfish were analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS), the official method for the detection of lipophilic toxins. The performance of this procedure was demonstrated to be fit for purpose and was validated in house following European guidelines. The vast majority of toxins present in shellfish belonged to the okadaic acid (OA) group and some samples from a particular area contained yessotoxin (YTX). Since these toxins occur very often with other lipophilic toxins, we evaluated the potential interactions among them. A human neuroblastoma cell line was used to study the possible synergies of OA with other lipophilic toxins. Results show that combination of OA with dinophysistoxin 2 (DTX2) or YTX enhances the toxicity triggered by OA, decreasing cell viability and cell proliferation, depending on the toxin concentration and incubation time. The effects of other lipophilic toxins as 13-desmethyl Spirolide C were also evaluated in vitro. PMID:25815891

  12. Prevalence and antimicrobial susceptibility of Vibrio parahaemolyticus isolated from retail shellfish in Shanghai

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vibrio parahaemolyticus is a marine and estuarine bacterium that poses a large threat to human health worldwide. It has been the leading bacterial cause of seafood-borne illness. This study investigated the prevalence and drug resistance of V. parahaemolyticus isolated from retail shellfish in Shang...

  13. Norovirus, hepatitis A virus and enterovirus presence in shellfish from high quality harvesting areas in Portugal.

    PubMed

    Mesquita, Joo R; Vaz, Lisa; Cerqueira, Snia; Castilho, Fernanda; Santos, Ricardo; Monteiro, Slvia; Manso, Carmen F; Romalde, Jesus L; Nascimento, Maria So Jos

    2011-08-01

    This is the first report on the screening of shellfish from Portugal for the presence of human enteropathogenic viruses. Approximately 2000 shellfish (Curbicula fluminea, Ruditapes decussatus, Tellina crassa, Spisula solida, Dosinia exoleta, Ensis spp., Mytilus spp., Ostrea edulis and Cerastoderma edule), organized in 49 batches, were collected between March 2008 and February 2009. They were tested for norovirus (NoV), hepatitis A virus (HAV) and enterovirus (EV) by RT-PCR followed by nucleotide sequencing. Bacterial contamination was also evaluated by Escherichia coli counts. Viral contamination was detected throughout the year in all shellfish species and in all collection areas, independently of their harvesting areas classification. Overall, 67% of all analyzed batches were contaminated by at least one of the studied viruses while the simultaneous presence of two and three viruses was detected in 22% and 6% batches, respectively. Of the three viruses, NoV was detected in 37% of the batches, followed by EV in 35%, and HAV in 33%. Nucleotide sequencing of the NoV and HAV RT-PCR products demonstrated that all strains belonged to NoV genotype GII.4 and HAV subgenotype 1B. The presence of NoV and HAV in shellfish from "A class" harvesting areas of Portugal can represent a potential health risk. PMID:21569936

  14. 78 FR 42820 - Agency Information Collection (Purchase of Shellfish) Activities Under OMB Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-17

    ....Regulations.gov ; or to VA's OMB Desk Officer, OMB Human Resources and Housing Branch, New Executive Office... ensure that the shellfish is packaged in a container that is marked with the packer's State certificate number and State abbreviation. In addition, the firm must ensure that the container is tagged ]...

  15. Heavy metal monitoring using bivalved shellfish from Zhejiang coastal waters, East China Sea.

    PubMed

    Huang, H; Wu, J Y; Wu, J H

    2007-06-01

    The interest of culturing bivalved shellfish (including mussels, clams, oysters etc.), has increased in recent years, but the consumption has been hampered both by high levels of heavy metals and toxic algae. The levels of heavy metals (Hg, Cd, Pb, Zn, Cu and As) were determined in soft tissues of different shellfish from Zhejiang coastal waters, East China Sea. The average concentrations of the heavy metals analyzed exhibited the following decreasing order: Zn > Cu > As > Cd > Pb > Hg. Comparison of heavy metals concentrations among species indicated that Bivalves clearly have significant potential as useful bioindicators; however, the results indicated that no one species is universally suitable, as is true of any organism used in these studies. The distribution of the metals was also investigated along the Zhejiang coast, which the results showed the mean concentration of Hg and Cd detected did not vary greatly and presented a similar spatial pattern at different sampling stations, the concentrations of Zn and Pb were highly variable at different sampling sites. The amounts of heavy metals in soft tissue of shellfish were also compared with those from the related species from other seas in China and world marine waters. The results suggested that the coastal area might be considered relatively unpolluted with heavy metals and the concentrations of metals in shellfish also below the seafood safety limits for human consumption. PMID:17057972

  16. 75 FR 13211 - Proposed Information Collection (Purchase of Shellfish) Activity: Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-18

    ... AFFAIRS Proposed Information Collection (Purchase of Shellfish) Activity: Comment Request AGENCY: Office of Acquisition and Logistics, Department of Veterans Affairs. ACTION: Notice. SUMMARY: The Office of Acquisition and Logistics (OA&L), Department of Veterans Affairs (VA), is announcing an opportunity for...

  17. 78 FR 22366 - Proposed Information Collection (Purchase of Shellfish) Activity: Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-15

    ... AFFAIRS Proposed Information Collection (Purchase of Shellfish) Activity: Comment Request AGENCY: Office of Acquisition and Logistics, Department of Veterans Affairs. ACTION: Notice. SUMMARY: The Office of Acquisition and Logistics (OA&L), Department of Veterans Affairs (VA), is announcing an opportunity for...

  18. First episode of shellfish contamination by palytoxin-like compounds from Ostreopsis species (Aegean Sea, Greece).

    PubMed

    Aligizaki, Katerina; Katikou, Panagiota; Nikolaidis, Georgios; Panou, Alexandra

    2008-03-01

    In order to investigate the toxicity of Ostreopsis species present in Greek coastal waters, cultures of Ostreopsis sp. and Ostreopsis ovata, mixed Ostreopsis field populations and shellfish collected from coastal waters of North Aegean Sea during late summer and autumn periods of 2004, 2005 and 2006 were examined by both mouse bioassay (MBA) and hemolysis neutralization assay (HNA). MBA testing was based on two different extraction protocols, while HNA also included the use of ouabain, a known palytoxin (PLT) antagonist. Results indicated the presence of a compound in both Ostreopsis cells and shellfish tissues, which was strongly toxic to mice. This compound exhibited characteristic symptomatology in mice (death, numbness, waddling gait and blindness) to that of PLT, as well as delayed hemolytic activity, which was neutralized by ouabain. HNA indicated that Ostreopsis cells contained a PLT-like compound (putative PLT, p-PLT) at concentrations ranging between 0.4 and 0.9 pg/cell, whereas concentration in shellfish tissues was estimated to range from about 33.3 to 97.0 microg p-PLT/kg tissue. To our knowledge, this is the first report of p-PLT contamination of shellfish by natural Ostreopsis species populations in European coastal waters and possibly globally, and also the first evidence on Ostreopsis cells' toxicity in the Eastern Mediterranean Sea. PMID:18067938

  19. Draft Genome Sequence of the Shellfish Larval Probiotic Bacillus pumilus RI06-95

    PubMed Central

    Hamblin, Meagan; Spinard, Edward; Gomez-Chiarri, Marta; Nelson, David R.

    2015-01-01

    Bacillus pumilus RI06-95 is a marine bacterium isolated in Narragansett, Rhode Island, which has shown probiotic activity against marine pathogens in larval shellfish. We report the genome of B. pumilus RI06-95, which provides insight into the microbe’s probiotic ability and may be used in future studies of the probiotic mechanism. PMID:26337873

  20. Draft Genome Sequence of the Shellfish Larval Probiotic Bacillus pumilus RI06-95.

    PubMed

    Hamblin, Meagan; Spinard, Edward; Gomez-Chiarri, Marta; Nelson, David R; Rowley, David C

    2015-01-01

    Bacillus pumilus RI06-95 is a marine bacterium isolated in Narragansett, Rhode Island, which has shown probiotic activity against marine pathogens in larval shellfish. We report the genome of B.pumilus RI06-95, which provides insight into the microbe's probiotic ability and may be used in future studies of the probiotic mechanism. PMID:26337873

  1. Disease management strategies for shellfish aquaculture: the important role of hatcheries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Disease management is a critical component of the successful production of bivalves. Infections by bacterial pathogens can cause rapid mortality of shellfish larvae with devastating consequences for both the hatcheries and the farmers that rely upon them. Furthermore, several bacterial and parasiti...

  2. Distribution of Marine Lipophilic Toxins in Shellfish Products Collected from the Chinese Market

    PubMed Central

    Wu, Haiyan; Yao, Jianhua; Guo, Mengmeng; Tan, Zhijun; Zhou, Deqing; Zhai, Yuxiu

    2015-01-01

    To investigate the prevalence of lipophilic marine biotoxins in shellfish from the Chinese market, we used hydrophilic interaction liquid chromatography-tandem mass spectrometry (LC-MS/MS) to measure levels of okadaic acid (OA), azaspiracid (AZA1), pectenotoxin (PTX2), gymnodimine (GYM), and spirolide (SPX1). We collected and analyzed 291 shellfish samples from main production sites along a wide latitudinal transect along the Chinese coastline from December 2008 to December 2009. Results revealed a patchy distribution of the five toxins and highlighted the specific geographical distribution and seasonal and species variation of the putative toxigenic organisms. All five lipophilic marine biotoxins were found in shellfish samples. The highest concentrations of OA, AZA1, PTX2, GYM, and SPX1 were 37.3, 5.90, 16.4, 14.4, and 8.97 μg/kg, respectively. These values were much lower than the legislation limits for lipophilic shellfish toxins. However, the value might be significantly underestimated for the limited detection toxins. Also, these toxins were found in most coastal areas of China and were present in almost all seasons of the year. Thus, these five toxins represent a potential threat to human health. Consequently, studies should be conducted and measures should be taken to ensure the safety of the harvested product. PMID:26184236

  3. 76 FR 65200 - Risk Assessment on Norovirus in Bivalve Molluscan Shellfish: Request for Comments and for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-20

    ... HUMAN SERVICES Food and Drug Administration Risk Assessment on Norovirus in Bivalve Molluscan Shellfish: Request for Comments and for Scientific Data and Information AGENCY: Food and Drug Administration, HHS. ACTION: Notice; request for comments and for scientific data and information. SUMMARY: The Food and...

  4. Occurrence and Antibiotic Resistance of Vibrio parahaemolyticus from Shellfish in Selangor, Malaysia.

    PubMed

    Letchumanan, Vengadesh; Pusparajah, Priyia; Tan, Loh Teng-Hern; Yin, Wai-Fong; Lee, Learn-Han; Chan, Kok-Gan

    2015-01-01

    High consumer demand for shellfish has led to the need for large-scale, reliable shellfish supply through aquaculture or shellfish farming. However, bacterial infections which can spread rapidly among shellfish poses a major threat to this industry. Shellfish farmers therefore often resort to extensive use of antibiotics, both prophylactically and therapeutically, in order to protect their stocks. The extensive use of antibiotics in aquaculture has been postulated to represent a major contributing factor in the rising incidence of antimicrobial resistant pathogenic bacteria in shellfish. This study aimed to investigate the incidence of pathogenic Vibrio parahaemolyticus and determine the antibiotic resistance profile as well as to perform plasmid curing in order to determine the antibiotic resistance mediation. Based on colony morphology, all 450 samples tested were positive for Vibrio sp; however, tox-R assay showed that only 44.4% (200/450) of these were V. parahaemolyticus. Out of these 200 samples, 6.5% (13/200) were trh-positive while none were tdh-positive. Antibiotic resistance was determined for all V. parahaemolyticus identified against 14 commonly used antibiotics and the multiple antibiotic resistance index (MAR) was calculated. The isolates demonstrated high resistance to several antibiotics tested- including second and third-line antibiotics- with 88% resistant to ampicillin, 81% to amikacin,70.5% to kanamycin, 73% to cefotaxime, and 51.5% to ceftazidime. The MAR index ranged from 0.00 to 0.79 with the majority of samples having an index of 0.36 (resistant to five antibiotics). Among the 13 trh-positive strains, almost 70% (9/13) demonstrated resistance to 4 or more antibiotics. Plasmid profiling for all V. parahaemolyticus isolates revealed that 86.5% (173/200) contained plasmids - ranging from 1 to 7 plasmids with DNA band sizes ranging from 1.2 kb to greater than 10 kb. 6/13 of the pathogenic V. pathogenic strains contained plasmid. After plasmid curing, the plasmid containing pathogenic strains isolated in our study have chromosomally mediated ampicillin resistance while the remaining resistance phenotypes are plasmid mediated. Overall, our results indicate that while the incidence of pathogenic V. parahaemolyticus in shellfish in Selangor still appears to be at relatively reassuring levels, antibiotic resistance is a real concern and warrants ongoing surveillance. PMID:26697003

  5. Occurrence and Antibiotic Resistance of Vibrio parahaemolyticus from Shellfish in Selangor, Malaysia

    PubMed Central

    Letchumanan, Vengadesh; Pusparajah, Priyia; Tan, Loh Teng-Hern; Yin, Wai-Fong; Lee, Learn-Han; Chan, Kok-Gan

    2015-01-01

    High consumer demand for shellfish has led to the need for large-scale, reliable shellfish supply through aquaculture or shellfish farming. However, bacterial infections which can spread rapidly among shellfish poses a major threat to this industry. Shellfish farmers therefore often resort to extensive use of antibiotics, both prophylactically and therapeutically, in order to protect their stocks. The extensive use of antibiotics in aquaculture has been postulated to represent a major contributing factor in the rising incidence of antimicrobial resistant pathogenic bacteria in shellfish. This study aimed to investigate the incidence of pathogenic Vibrio parahaemolyticus and determine the antibiotic resistance profile as well as to perform plasmid curing in order to determine the antibiotic resistance mediation. Based on colony morphology, all 450 samples tested were positive for Vibrio sp; however, tox-R assay showed that only 44.4% (200/450) of these were V. parahaemolyticus. Out of these 200 samples, 6.5% (13/200) were trh-positive while none were tdh-positive. Antibiotic resistance was determined for all V. parahaemolyticus identified against 14 commonly used antibiotics and the multiple antibiotic resistance index (MAR) was calculated. The isolates demonstrated high resistance to several antibiotics tested- including second and third-line antibiotics- with 88% resistant to ampicillin, 81% to amikacin,70.5% to kanamycin, 73% to cefotaxime, and 51.5% to ceftazidime. The MAR index ranged from 0.00 to 0.79 with the majority of samples having an index of 0.36 (resistant to five antibiotics). Among the 13 trh-positive strains, almost 70% (9/13) demonstrated resistance to 4 or more antibiotics. Plasmid profiling for all V. parahaemolyticus isolates revealed that 86.5% (173/200) contained plasmids - ranging from 1 to 7 plasmids with DNA band sizes ranging from 1.2 kb to greater than 10 kb. 6/13 of the pathogenic V. pathogenic strains contained plasmid. After plasmid curing, the plasmid containing pathogenic strains isolated in our study have chromosomally mediated ampicillin resistance while the remaining resistance phenotypes are plasmid mediated. Overall, our results indicate that while the incidence of pathogenic V. parahaemolyticus in shellfish in Selangor still appears to be at relatively reassuring levels, antibiotic resistance is a real concern and warrants ongoing surveillance. PMID:26697003

  6. Spatial and temporal heterogeneity of bacteria across an intertidal shellfish bed: implications for regulatory monitoring of faecal indicator organisms.

    PubMed

    Clements, Katie; Quilliam, Richard S; Jones, David L; Wilson, James; Malham, Shelagh K

    2015-02-15

    Routine bacterial monitoring of shellfish beds using indicator species is a common global practice designed to prevent human consumption of contaminated shellfish products. However, current bacteriological monitoring procedures which focus on the quantification of faecal indicator organisms (FIOs) as a proxy for microbial pollution may not be representative of total bacterial contamination levels present in shellfish harvesting areas. The objective of this study was to critically assess the accuracy of current monitoring strategies by quantifying the spatial (lateral and longitudinal distance) and temporal (seasonality and tidal state) concentrations of FIOs (Escherichia coli and total coliforms) within a single intertidal commercially harvested shellfish bed. Spatial and temporal FIO dynamics, including the effects of tidal state and seasonality, were quantified in mussel flesh and sediment samples from a single intertidal mussel (Mytilus edulis) bed. Our results confirmed that FIO concentrations across a shellfish bed were heterogeneous over larger spatial and temporal scales, but showed no relation to the concentrations of autochthonous bacteria, such as Vibrio spp., or the physico-chemical parameters of the sediment. These results have important implications for both public health and the economic prosperity of the shellfish industry, and demonstrate the importance of accommodating both spatial and temporal fluctuations in routine bacteriological monitoring protocols. We conclude that current FIO monitoring procedures may not accurately represent levels of microbial contamination within shellfish harvesting areas and that more robust microbiological testing procedures need developing. PMID:25460933

  7. Development and use of a pepsin digestion method for analysis of shellfish for Cryptosporidium oocysts and Giardia cysts.

    PubMed

    Robertson, L J; Gjerde, B

    2008-05-01

    Investigation of shellfish for Cryptosporidium oocysts and Giardia cysts is of public health interest because shellfish may concentrate these pathogens in their bodies, and because shellfish are frequently eaten raw or lightly cooked. To date, the methods used for the analysis of shellfish for these parasites are based on those originally designed for water concentrates or fecal samples; the reported recovery efficiencies are frequently relatively low and the amount of sample examined is small. Here, we describe the development and use of a pepsin digestion method for analyzing shellfish samples for these parasites. The conditions of the isolation method did not affect subsequent parasite detection by immunofluorescent antibody test, and allowed examination of 3-g samples of shellfish homogenate, with recovery efficiencies from blue mussel homogenates of between 70 and 80%, and similar recoveries from horse mussel and oyster homogenates. Although exposure of the parasites to the conditions used in the technique affected their viability, as assessed by vital dyes, the maximum reduction in viability after 1-h incubation in digestion solution was 20%. In a preliminary survey of shellfish collected from the Norwegian coast, Cryptosporidium oocysts were detected in blue mussel homogenates in 6 (43%) of 14 batches and Giardia cysts in 7 (50%) of these batches. However, this relatively high occurrence, compared with other surveys, may be due to the higher recovery efficiency of the new method, and the relatively large sample size analyzed. A more comprehensive study of the occurrence of these parasites in shellfish would be of pertinence to the Norwegian shellfish industry. PMID:18522030

  8. Chlorinated and brominated organic pollutants in shellfish from the Yellow Sea and East China Sea.

    PubMed

    Yin, Ge; Asplund, Lillemor; Qiu, Yanling; Zhou, Yihui; Wang, Hua; Yao, Zongli; Jiang, Jianbin; Bergman, Åke

    2015-02-01

    The global contamination with persistent organic pollutants (POPs), or compounds with similar characteristics, is well known. Still there are data gaps for POP concentrations from many areas in the world. The aim of the present study is to assess several legacies POPs and also hexabromocyclododecane (HBCDD) and methoxylated polybrominated diphenyl ethers (MeO-PBDEs) in shellfish from three locations in the Yellow Sea and East China Sea. The sources of the contaminants are discussed. Pooled samples were treated by liquid-liquid extraction and acid and column cleanup prior to analysis by gas chromatogram equipped with electron capture detector (GC-ECD) and gas chromatography-mass spectrometry (GC-MS). The by far most abundant environmental contaminant originates from dichlorodiphenyltrichloroethane (DDT), independent of species analyzed or sampling site. The results indicate ongoing or at least recent discharges of DDT. The second highest concentrations were reported for HBCDD (21-40 ng/g fat) in the shellfish, independent of sampling sites. The two natural products, 6-MeO-BDE-47 and 2'-MeO-BDE-68, were also present in the shellfish (1.3-22 and 1-14 ng/g fat, respectively). The polychlorinated biphenyl (PCB) congener CB-153 (0.8-6.5 ng/g fat), hexachlorobenzene (HCB) (1.1-3.6 ng/g fat), and β-hexachlorocyclohexane (β-HCH) (2.3-4.9 ng/g fat) were all higher than the concentrations of other HCH isomers, β-endosulfan, PBDE congeners, and mirex. Apart from the DDTs and HBCDDs, it is evident that the pollution of shellfish was similar to, or lower than, the contamination of shellfish in other parts of the world. PMID:24958534

  9. Bio-filler from waste shellfish shell: preparation, characterization, and its effect on the mechanical properties on polypropylene composites.

    PubMed

    Li, Hai-Yan; Tan, Ye-Qiang; Zhang, Lu; Zhang, Yun-Xiang; Song, Yi-Hu; Ye, Ying; Xia, Mei-Sheng

    2012-05-30

    Waste shellfish shell stacking with a significant odor and toxicity which are hazardous to human constitutes a serious environmental hazard. For utilization of waste shellfish shell resource, granule of shellfish shell (SS) was prepared from waste shellfish shell by removing cuticle, crushing, grinding and shearing emulsification and was introduced as a filler to reinforce polypropylene (PP). The mechanical behavior of PP/SS composite shows a higher yield strain, yield strength, tensile strength and elongation at break than traditional commercial calcium carbonate (CC) filled PP. Yield strength of PP/SS composite with 2% SS is improved by 11.1% due to the formation of ?-crystalline PP phase. Using waste SS for producing bio-filler for filling PP is an effective and prospective measure to deal with waste SS, which is valuable for industrial production and practical application as fillers for reinforcing polymers. PMID:22476096

  10. RELATIONS OF FISH AND SHELLFISH DISTRIBUTIONS TO HABITAT AND WATER QUALITY IN THE MOBILE BAY ESTUARY, USA

    EPA Science Inventory

    The Mobile Bay estuary provides rich habitat for many fish and shellfish, including those identified as economically and ecologically important. The National Estuary Program has focused on restoration of degraded estuarine habitat on which these species depend. To support this ...

  11. Brevetoxin B4 isolated from greenshell mussels Perna canaliculus, the major toxin involved in neurotoxic shellfish poisoning in New Zealand.

    PubMed

    Morohashi, A; Satake, M; Naoki, H; Kaspar, H F; Oshima, Y; Yasumoto, T

    1999-01-01

    A new brevetoxin B analog, brevetoxin B4 (BTXB4), was isolated as the major toxin in greenshell mussels, Perna canaliculus, collected in New Zealand at the time of the neurotoxic shellfish poisoning incident. The new analog accounted for nearly two-thirds of the mouse lethality of the shellfish and was determined to be a mixture of N-myristoyl-BTXB2 and N-palmitoyl-BTXB2. PMID:10495465

  12. Levels of polychlorinated biphenyls and organochlorine pesticides in edible shellfish from Xiamen (China) and estimation of human dietary intake.

    PubMed

    Zhang, Jie; Liu, Feng; Chen, Rongbin; Feng, Tao; Dong, Sijun; Shen, Heqing

    2012-12-01

    Xiamen is a representative coastal city in China. Shellfish is widely consumed by local people. A broad spectrum of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were measured in representative shellfish from Xiamen. Despite being banned many years ago, these chemicals were still detected at varying levels. The total PCB levels ranged from 0.48 to 3.28 ng/g wet wt. for the shellfish surveyed. The tetra-, penta- and hexa-PCB congeners were found to be predominant. The estimated WHO-TEQ PCB intakes through shellfish consumption ranged from 0.063 to 0.102 pg/kg body wt. for Xiamen adults and children, which were significantly lower than tolerable weekly intake. Among OCPs, DDTs were predominant, followed by aldrin-like chemicals and endosulfans. The increase in aldrin-like chemicals and endosulfans, and the decrease in DDTs were observed in this study when compared to historical data in Xiamen. HCHs, chlordanes, HCB, heptachlors and mirex were detected with low concentrations in the shellfish. The estimated intakes of OCPs were several orders lower than tolerable daily intakes. However, the high carcinogenic risk of aldrin and dieldrin were found in the measured shellfish species. p,p'-DDD, p'p-DDT, ?-HCH and ?-HCH in certain species should also be concerned for their potential carcinogenic risks. PMID:22982472

  13. Fatal paralytic shellfish poisoning in Kittlitz's Murrelet (Brachyramphus brevirostris) nestlings, Alaska, USA.

    PubMed

    Shearn-Bochsler, Valerie; Lance, Ellen W; Corcoran, Robin; Piatt, John; Bodenstein, Barbara; Frame, Elizabeth; Lawonn, James

    2014-10-01

    Paralytic shellfish poisoning (PSP) is an acute toxic illness in humans resulting from ingestion of shellfish contaminated with a suite of neurotoxins (saxitoxins) produced by marine dinoflagellates, most commonly in the genus Alexandrium. Poisoning also has been sporadically suspected and, less often, documented in marine wildlife, often in association with an outbreak in humans. Kittlitz's Murrelet (Brachyramphus brevirostris) is a small, rare seabird of the Northern Pacific with a declining population. From 2008 to 2012, as part of a breeding ecology study, multiple Kittlitz's Murrelet nests on Kodiak Island, Alaska, were monitored by remote cameras. During the 2011 and 2012 breeding seasons, nestlings from several sites died during mild weather conditions. Remote camera observations revealed that the nestlings died shortly after consuming sand lance (Ammodytes hexapterus), a fish species known to biomagnify saxitoxin. High levels of saxitoxin were subsequently documented in crop content in 87% of nestling carcasses. Marine bird deaths from PSP may be underreported. PMID:25098307

  14. PCR-based assessment of shellfish traceability and sustainability in international Mediterranean seafood markets.

    PubMed

    Galal-Khallaf, Asmaa; Ardura, Alba; Borrell, Yaisel J; Garcia-Vazquez, Eva

    2016-07-01

    Two mitochondrial markers (cytochrome oxidase COI and 16S rDNA) were employed for species identification of commercial shellfish from two Mediterranean countries. New COI Barcodes were generated for six species: Pleoticus robustus, Metapenaeopsis barbata, Parapenaeus fissuroides, Hymenopenaeus debilis, Metapenaeus affinis and Sepia aculeata. Biodiversity of the seafood species analyzed was greater in Egypt, with nine crustacean and two cephalopod species found compared with only three crustaceans and three cephalopods in Spain. In total, 17.2% and 15.2% products were mislabeled in Egypt and Spain, respectively. Population decline is a problem for some of the substitute species. Others were exotic and/or invasive in exporters' regions. This study offers the first comparable study of shellfish traceability in these Mediterranean markets. The PCR-based method used in this study proved to be reliable, effective and, therefore, could be employed for routine seafood analysis. PMID:26920298

  15. A new simple screening method for the detection of paralytic shellfish poisoning toxins

    NASA Astrophysics Data System (ADS)

    Cheng, Jinping; Pi, Shuaishuai; Ye, Shufeng; Gao, Haomin; Yao, Lei; Jiang, Zhenyi; Song, Yuling; Xi, Lei

    2012-09-01

    The current testing for paralytic shellfish poisoning (PSP) in shellfish is based on the mouse bioassay (MBA). To alleviate animal welfare concerns, we evaluated the utility of using sublethal indicators of toxicity as an alternative to measuring time to death. Live mice were injected with a PSP congener and the changes in neurotransmitter levels were measured 60, 90, and 120 min after injection. Acetylcholine (ACh) was the most sensitive marker for PSP toxicity. The changes in neurotransmitter levels were most pronounced in the blood. Thus, measurement of Ach levels in the blood may serve as a sensitive predictor for PSP that would not require sacrifice of the mice. This method was relatively simple, sensitive (less than 1 μg/kg weight, equivalent to 20 ng/mL), low maintenance, and rapid (less than 60 min).

  16. Fatal paralytic shellfish poisoning in Kittlitz's Murrelet (Brachyramphus brevirostris) nestlings, Alaska, USA

    USGS Publications Warehouse

    Shearn-Bochsler, Valerie I.; Lance, Ellen W.; Corcoran, Robin; Piatt, John; Bodenstein, Barbara; Frame, Elizabeth; Lawonn, James

    2014-01-01

    Paralytic shellfish poisoning (PSP) is an acute toxic illness in humans resulting from ingestion of shellfish contaminated with a suite of neurotoxins (saxitoxins) produced by marine dinoflagellates, most commonly in the genus Alexandrium. Poisoning also has been sporadically suspected and, less often, documented in marine wildlife, often in association with an outbreak in humans. Kittlitz's Murrelet (Brachyramphus brevirostris) is a small, rare seabird of the Northern Pacific with a declining population. From 2008 to 2012, as part of a breeding ecology study, multiple Kittlitz's Murrelet nests on Kodiak Island, Alaska, were monitored by remote cameras. During the 2011 and 2012 breeding seasons, nestlings from several sites died during mild weather conditions. Remote camera observations revealed that the nestlings died shortly after consuming sand lance (Ammodytes hexapterus), a fish species known to biomagnify saxitoxin. High levels of saxitoxin were subsequently documented in crop content in 87% of nestling carcasses. Marine bird deaths from PSP may be underreported.

  17. A Natural and Concurrent Interferent in Bolinus brandaris with Consequences on Amnesic Shellfish Poisoning Risk Management.

    PubMed

    Papiol, Gemma Gimnez

    2015-01-01

    Regulations aimed to protect public health from amnesic shellfish poisoning (ASP) are focused on the detection and accurate quantification of domoic acid (DA). The reference detection determination used by the different shellfish safety monitoring agencies worldwide is HPLC separation followed by UV detection, in which different chromatographic column lengths or brands are accepted as long as it is C18 column. A laboratory validation of this method showed different performance of two accepted chromatographic columns when analyzing Bolinus brandaris samples. A natural compound, present only in those samples that contained DA, was evidenced by one of the columns. The DA quantification obtained with the column that coelutes both compounds was approximately twice the amount obtained with the column that separates them. This difference has important consequences in the ASP toxins management for this fishery. The identity and toxicity of the compound are still unknown. PMID:25857882

  18. Evidence that mortality from Vibrio vulnificus infection results from single strains among heterogeneous populations in shellfish.

    PubMed

    Jackson, J K; Murphree, R L; Tamplin, M L

    1997-08-01

    Vibrio vulnificus is the leading cause of food-related mortality reported in the state of Florida. It is normal microflora in marine environments, where seawater and molluscan shellfish are the primary vectors of V. vulnificus disease. Risk correlates with seasonally high numbers of V. vulnificus bacteria during the summer months. Currently, the infectious dose for humans, as well as whether the disease is caused by single or multiple strains found in molluscan shellfish, is unknown. In this work, we studied pulsed-field gel electrophoresis profiles of V. vulnificus strains isolated from blood and oysters associated with V. vulnificus disease. Results showed that ca. 10(3) V. vulnificus bacteria/gram of oyster and higher concentrations were associated with human infections and that a single V. vulnificus strain, evidenced by pulsed-field gel electrophoresis profiles, was isolated from human tissues. PMID:9230389

  19. Use of Rotavirus Virus-Like Particles as Surrogates To Evaluate Virus Persistence in Shellfish

    PubMed Central

    Loisy, Fabienne; Atmar, Robert L.; Le Saux, Jean-Claude; Cohen, Jean; Caprais, Marie-Paule; Pommepuy, Monique; Le Guyader, Françoise S.

    2005-01-01

    Rotavirus virus-like particles (VLPs) and MS2 bacteriophages were bioaccumulated in bivalve mollusks to evaluate viral persistence in shellfish during depuration and relaying under natural conditions. Using this nonpathogenic surrogate virus, we were able to demonstrate that about 1 log10 of VLPs was depurated after 1 week in warm seawater (22°C). Phage MS2 was depurated more rapidly (about 2 log10 in 1 week) than were VLPs, as determined using a single-compartment model and linear regression analysis. After being relayed in the estuary under the influence of the tides, VLPs were detected in oysters for up to 82 days following seeding with high levels of VLPs (concentration range between 1010 and 109 particles per g of pancreatic tissue) and for 37 days for lower contamination levels (105 particles per g of pancreatic tissue). These data suggest that viral particles may persist in shellfish tissues for several weeks. PMID:16204520

  20. Multiple clusters of norovirus among shellfish consumers linked to symptomatic oyster harvesters.

    PubMed

    McIntyre, Lorraine; Galanis, Eleni; Mattison, Kirsten; Mykytczuk, Oksana; Buenaventura, Enrico; Wong, Julie; Prystajecky, Natalie; Ritson, Mark; Stone, Jason; Moreau, Dan; Youssef, Andr

    2012-09-01

    We describe the investigation of a norovirus outbreak associated with raw oyster consumption affecting 36 people in British Columbia, Canada, in 2010. Several genotypes were found in oysters, including an exact sequence match to clinical samples in regions B and C of the norovirus genome (genogroup I genotype 4). Traceback implicated a single remotely located harvest site probably contaminated by ill shellfish workers during harvesting activities. This outbreak resulted in three recalls, one public advisory, and closure of the harvest site. PMID:22947481

  1. Biotransformations of paralytic shellfish toxins by bacteria isolated from bivalve molluscs.

    PubMed

    Smith, E A; Grant, F; Ferguson, C M; Gallacher, S

    2001-05-01

    Due to the possibility that bacteria could be involved in the clearance of paralytic shellfish toxins (PST) from bivalve molluscs, investigations into which, if any, bacteria were able to grow at the expense of PST focused on several common shellfish species. These species were blue mussels, oysters, razor fish, cockles, and queen and king scallops. Bacteria associated with these shellfish were isolated on marine agar 2216 and characterized by their carbon utilization profiles (BIOLOG). Selected isolates from groups demonstrating 90% similarity were screened for their ability to metabolize a range of PST (gonyautoxins 1 and 4 [GTX 1/4], GTX 2/3, GTX 5, saxitoxin, and neosaxitoxin) using a novel screening method and confirming its results by high-performance liquid chromatography. Results suggest that molluscan bacteria have different capacities to utilize and transform PST analogues. For example, isolates M12 and R65 were able to reductively transform GTX 1/4 with concomitant production of GTX 2/3, while isolate Q5 apparently degraded GTX 1/4 without the appearance of other GTXs. Other observed possible mechanisms of PST transformations include decarbamoylation by isolate M12 and sulfation of GTXs by isolates Q5, R65, M12, and C3. These findings raise questions as to the possible role of bacteria resident in the shellfish food transport system. Some researchers have suggested that the microflora play a role in supplying nutritional requirements of the host. This study demonstrates that bacteria may also be involved in PST transformation and elimination in molluscan species. PMID:11319121

  2. Human exposure to perfluorinated compounds in Catalonia, Spain: contribution of drinking water and fish and shellfish.

    PubMed

    Domingo, José L; Ericson-Jogsten, Ingrid; Perelló, Gemma; Nadal, Martí; Van Bavel, Bert; Kärrman, Anna

    2012-05-01

    In this study, the concentrations of 15 perfluorinated compounds (PFCs) were analyzed in 30 water samples collected in Catalonia (Spain) at three stages of the drinking water treatment process in several water purification plants. In addition, the concentrations of 13 PFCs were determined in samples of fish and shellfish collected from coastal areas of Catalonia. The intake of PFCs through both pathways, drinking water intake and fish and shellfish consumption, was also estimated. In water samples, the highest mean concentrations corresponded to perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) (1.81 and 2.40 ng/L, respectively), whereas perfluorodecanosulfonate (PFDS) and perfluorotetradecanoic acid (PFTDA) were under their respective limits of detection in all analyzed samples. The results show that although the current treatment processes caused slight reductions in PFC concentrations, these processes did not mean significant changes in the amounts of PFCs already contained in the raw water. Among the analyzed PFCs in fish and shellfish, only seven compounds could be detected in at least one composite sample. PFOS showed the highest mean concentration (2.70 ng/g fw), being detected in all species with the exception of mussels. With regard to PFOA (mean, 0.074 ng/g fw), the highest concentrations were detected in prawn and hake (0.098 and 0.091 ng/g fw, respectively). The current exposure to PFCs through consumption of fish and shellfish indicates that it should not be of concern for the consumers. The amounts ingested are well below the recommended tolerable daily intakes, at least for those PFCs for which information is available. PMID:22494245

  3. Single-Laboratory Validation of a Multitoxin Ultra-Performance LC-Hydrophilic Interaction LC-MS/MS Method for Quantitation of Paralytic Shellfish Toxins in Bivalve Shellfish.

    PubMed

    Turner, Andrew D; McNabb, Paul S; Harwood, D Tim; Selwood, Andrew I; Boundy, Michael J

    2015-01-01

    A single-laboratory validation study was conducted for the hydrophilic interaction-LC-MS/MS analysis of paralytic shellfish toxins (PSTs) in bivalve shellfish. The method was developed as an alternative to the precolumn oxidation AOAC 2005.06 and postcolumn oxidation AOAC 2011.02 LC with fluorescence detection methods, receptor binding assay AOAC 2011.27, as well as the mouse bioassay AOAC 959.08. PSTs assessed were saxitoxin, neosaxitoxin, deoxydecarbamoylsaxitoxin, decarbamoylsaxitoxin, decarbamoylneosaxitoxin, gonyautoxins 1-6, decarbamoylgonyautoxins 2-3, and N-sulfocarbamoyl gonyautoxins 2&3. The method also included the determination of decarbamoylgonyautoxins 1&4, N-sulfocarbamoyl gonyautoxins 1&4, and M toxins. Twelve commercially produced bivalve species from both New Zealand and the United Kingdom were assessed, including mussels, oysters, scallops, and clams. Validation studies demonstrated acceptable method performance characteristics for specificity, linearity, recovery, repeatability, and within-laboratory reproducibility. LOD and LOQ were significantly improved in comparison to current fluorescence-based detection methods, and the method was shown to be rugged. The method performed well in comparison to AOAC 2005.06, with evidence obtained from both comparative analysis of 1141 PST-contaminated samples and successful participation in proficiency testing schemes. The method is suitable for use in regulatory testing and will be submitted for an AOAC collaborative study. PMID:26024657

  4. Heat treatment and the use of additives to improve the stability of paralytic shellfish poisoning toxins in shellfish tissue reference materials for internal quality control and proficiency testing.

    PubMed

    Burrell, Stephen; Clion, Valentin; Auroy, Virginie; Foley, Barry; Turner, Andrew D

    2015-06-01

    The need for homogenous reference materials stable for paralytic shellfish toxins is vital for the monitoring and quality assurance of these potent neurotoxins in shellfish. Two stabilisation techniques were investigated, heat treatment through autoclaving and the addition of preserving additives into the tissue matrix. Short and long-term stability experiments as well as homogeneity determination were conducted on materials prepared by both techniques in comparison with an untreated control using two LC-FLD methods. Both techniques improved the stability of the matrix and the PSP toxins present compared to the controls. A material was prepared using the combined techniques of heat treatment followed by spiking with additives and data is presented from this optimised reference material as used over a two year period in the Irish national monitoring program and in a development exercise as part of a proficiency testing scheme operated by QUASIMEME (Quality Assurance of Information for Marine Environmental Monitoring in Europe) since 2011. The results were indicative of the long-term stability of the material as evidenced through consistent assigned values in the case of the proficiency testing scheme and a low relative standard deviation of 10.5% for total toxicity data generated over 24 months. PMID:25816999

  5. Quantitative ELISA kit for paralytic shellfish toxins coupled with sample pretreatment.

    PubMed

    Sato, Shigeru; Takata, Yoshinobu; Kondo, Sunaho; Kotoda, Akiko; Hongo, Naoto; Kodama, Masaaki

    2014-01-01

    A new ELISA kit to quantitate the level of paralytic shellfish poisoning (PSP) toxins in crude shellfish extracts was developed. A conjugate for preparing antigen and a novel antibody used in the ELISA was prepared based on the unique reactions between C11-O-sulfate toxins such as gonyautoxins 2 and 3 (GTX2,3) and various thiol compounds, followed by coupling to keyhole limpet hemocyanin. The compounds necessary for competitive ELISA, labeled toxin and an artificial standard toxin to replace saxitoxin in the analysis, were also produced by the same techniques. The resulting ELISA recognized all the toxin components tested; however, carbamoyl-N-sulfate derivatives such as B and C toxins and N1-OH toxins such as neoSTX and GTX1,4 showed low affinity to the antibody. The difference in the reactivity of the antibody observed among the toxin components prevents accurate quantification of the toxin amounts in shellfish extracts. To address this problem, the former toxin components were transformed to corresponding carbamate toxins by mild HCl treatment according to a conventional method. The reduction of N1-OH of the latter toxins to N1-H was performed by our original method using hemin as a catalyst. We report here the new ELISA kit coupled with the pretreatment process to transform the toxin components favorable for the quantitative analysis of PSP toxins. PMID:24830145

  6. Benefits to shorebirds from invasion of a non-native shellfish

    PubMed Central

    Caldow, Richard W.G; Stillman, Richard A; Durell, Sarah E.A. le V. dit; West, Andy D; McGrorty, Selwyn; Goss-Custard, John D; Wood, Philippa J; Humphreys, John

    2007-01-01

    Introductions of non-native species are seen as major threats to ecosystem function and biodiversity. However, invasions of aquatic habitats by non-native species are known to benefit generalist consumers that exhibit dietary switches and prey upon the exotic species in addition to or in preference to native ones. There is, however, little knowledge concerning the population-level implications of such dietary changes. Here, we show that the introduction of the Manila clam Tapes philippinarum into European coastal waters has presented the Eurasian oystercatcher Haematopus ostralegus ostralegus with a new food resource and resulted in a previously unknown predatorprey interaction between these species. We demonstrate, with an individuals-based simulation model, that the presence of this non-native shellfish, even at the current low density, has reduced the predicted over-winter mortality of oystercatchers at one recently invaded site. Further increases in clam population density are predicted to have even more pronounced effects on the density dependence of oystercatcher over-winter mortality. These results suggest that if the Manila clam were to spread around European coastal waters, a process which is likely to be facilitated by global warming, this could have considerable benefits for many shellfish-eating shorebird populations. PMID:17412684

  7. Viral contamination of shellfish: evaluation of methods and analysis of bacteriophages and human viruses.

    PubMed

    Muniain-Mujika, I; Girones, R; Lucena, F

    2000-09-01

    Viral outbreaks attributed to the consumption of contaminated shellfish have been clearly demonstrated. Thirty-five samples of mussels collected from areas with two different levels of faecal pollution were analysed for somatic coliphages, F-RNA phages and bacteriophages infecting Bacteroides fragilis HSP40 and RYC2056 following standardised protocols, and for enterovirus, human adenovirus and hepatitis A virus by nucleic acid amplification (Nested-PCR and RT-PCR). Four methods for viral recovery from shellfish have been compared. The first method is based on borate buffer at pH 9.5 as eluent, the second is based on glycine buffer at pH 10 as eluent, a third method is based on glycine buffer at pH 7.5 and changes in conductivity and the fourth method on nutritive broth with Tween 80 as eluent. The results obtained were analysed statistically and the method based in glycine buffer at pH 10 seems to be the most efficient and useful for the recovery of phages and human viruses. The results also show a different pattern in the proportions between the viral parameters when the source of the faecal pollution is close to or distant from the shellfish growing area. PMID:10996644

  8. [Evaluation of recovery methods of Shigella species from fresh marine fish and shellfishes].

    PubMed

    Shimotori, S; Kojima, F; Harushima, H; Amako, K

    1990-10-01

    Recovery experiments of Shigella strains from fresh marine fish and shellfishes, including fresh sea urchin, which have been artificially contaminated with the strains, were performed using the improved Shigella broth-enrichment method and the culture method reported by Mehlman et al. All of the 43 Shigella stock cultures strains tested were recovered easily by the enrichment method from sea urchin individuals inoculated with a small number of viable cells of each strain. That is, a total of 24 strains (56%) were recovered from sea urchin individuals inoculated with less than 10 viable cells per one individual, and the other 19 strains were also recovered when 10 to 1,000 cells of each strain were inoculated. Recovery of Shigella strains from fish and shellfishes by the enrichment method was hardly affected by the number of contaminated bacteria (SPC, standard plate counts) in these materials. In order to confirm reliability of the enrichment method, similar experiments were performed using S. flexneri strain B as the inoculum and more fish and shellfishes as the samples (24 specimens of fresh sea urchins, 11 specimens of fresh oysters and 5 other specimens including prawns). Except for one oyster specimen which showed an especially high SPC value, the inoculum was able to be recovered from most of the materials inoculated with less than 10 viable cells, and all of the tested samples became Shigella positive when they were inoculated with up to 1,000 viable cells.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2258650

  9. Sediment bacterial indicators in an urban shellfishing subestuary of the lower Chesapeake Bay.

    PubMed Central

    Erkenbrecher, C W

    1981-01-01

    The objectives of this study were to document the spatial and temporal distributions and compositions of bacteria in the sediments and overlying waters of an important urban shellfishing area in the lower Chesapeake Bay region, the Lynnhaven Estuary. Marked fluctuations were observed in the date of many of the physicochemical parameters and the indicator bacteria. The higher-salinity water and coarser sediment of the inlet site showed lower overall bacterial densities than did the headwater sites, where freshwater runoff and decreased tidal action were characteristic. Densities of benthic indicator bacteria, when expressed on a volumetric basis, were significantly greater than counts in the overlying waters. These counts were indicative of a fecally polluted system and were well above the safe maximum limits for shellfish-growing waters. Significantly fewer total and fecal bacteria were observed in both the water and the sediment during the warm months of May, July, and August. The primary sources of the Lynnhaven's bacterial pollution appeared to be typical of urban and agricultural runoff, although failure of septic tank systems was suspected as a problem in the Lynnhaven's western branch. These results illustrated that sediments in shellfishing areas could serve as a reservoir for high densities of indicator bacteria and that, potentially, pathogens could pose a health hazard. PMID:7294785

  10. New insights into the causes of human illness due to consumption of azaspiracid contaminated shellfish

    PubMed Central

    Chevallier, O. P.; Graham, S. F.; Alonso, E.; Duffy, C.; Silke, J.; Campbell, K.; Botana, L. M.; Elliott, C. T.

    2015-01-01

    Azaspiracid (AZA) poisoning was unknown until 1995 when shellfish harvested in Ireland caused illness manifesting by vomiting and diarrhoea. Further in vivo/vitro studies showed neurotoxicity linked with AZA exposure. However, the biological target of the toxin which will help explain such potent neurological activity is still unknown. A region of Irish coastline was selected and shellfish were sampled and tested for AZA using mass spectrometry. An outbreak was identified in 2010 and samples collected before and after the contamination episode were compared for their metabolite profile using high resolution mass spectrometry. Twenty eight ions were identified at higher concentration in the contaminated samples. Stringent bioinformatic analysis revealed putative identifications for seven compounds including, glutarylcarnitine, a glutaric acid metabolite. Glutaric acid, the parent compound linked with human neurological manifestations was subjected to toxicological investigations but was found to have no specific effect on the sodium channel (as was the case with AZA). However in combination, glutaric acid (1mM) and azaspiracid (50nM) inhibited the activity of the sodium channel by over 50%. Glutaric acid was subsequently detected in all shellfish employed in the study. For the first time a viable mechanism for how AZA manifests itself as a toxin is presented. PMID:25928256

  11. Indirect human impacts turn off reciprocal feedbacks and decrease ecosystem resilience.

    PubMed

    Bertness, Mark D; Brisson, Caitlin P; Crotty, Sinead M

    2015-05-01

    Creek bank salt marsh die-off is a conservation problem in New England, driven by predator depletion, which releases herbivores from consumer control. Many marshes, however, have begun to recover from die-off. We examined the hypothesis that the loss of the foundation species Spartina alterniflora has decreased facilitator populations, weakening reciprocal positive plant/animal feedbacks, resilience, and slowing recovery. Field surveys and experiments revealed that loss of Spartina leads to decreased biodiversity, and increased mortality and decreased growth of the ribbed mussel Geukensia demissa, a key facilitator of Spartina. Experimental addition of Geukensia facilitators to creek banks accelerated Spartina recovery, showing that their loss limits recovery and the reciprocal feedbacks that drive community resilience. Reciprocal positive feedbacks involving foundation species, often lost to human impacts, may be a common, but generally overlooked mechanism of ecosystem resilience, making their reestablishment a valuable restoration tool. PMID:25432574

  12. On the Frontline: Tracking Ocean Acidification in an Alaskan Shellfish Hatchery

    PubMed Central

    Evans, Wiley; Mathis, Jeremy T.; Ramsay, Jacqueline; Hetrick, Jeff

    2015-01-01

    The invasion of anthropogenic carbon dioxide (CO2) into the ocean is shifting the marine carbonate system such that saturation states of calcium carbonate (CaCO3) minerals are decreasing, and this is having a detrimental impact on early life stages of select shellfish species. The global, secular decrease in CaCO3 saturation states is occurring on top of a backdrop of large natural variability in coastal settings; progressively shifting the envelope of variability and leading to longer and more frequent exposure to adverse conditions. This is a great concern in the State of Alaska, a high-latitude setting vulnerable to rapid changes in the marine carbonate system, where an emerging shellfish industry plans major growth over the coming decades. Currently, the Alutiiq Pride Shellfish Hatchery (APSH) in Seward, Alaska is the only hatchery in the state, and produces many shellfish species with early life stages known to be sensitive to low CaCO3 saturation states. Here we present the first land-based OA measurements made in an Alaskan shellfish hatchery, and detail the trends in the saturation state of aragonite (?arag), the more soluble form of CaCO3, over a 10-month period in the APSH seawater supply. These data indicate the largest changes are on the seasonal time scale, with extended periods of sub-optimal ?arag levels (?arag < 1.5) in winter and autumn associated with elevated water column respiration and short-lived runoff events, respectively. The data pinpoint a 5-month window of reprieve with favorable ?arag conditions above the sub-optimal ?arag threshold, which under predicted upper-bound CO2 emissions trajectories is estimated to close by 2040. To date, many species in production at APSH remain untested in their response to OA, and the data presented here establish the current conditions at APSH as well as provide a framework for hatchery-based measurements in Alaska. The current and expected conditions seen at APSH are essential to consider for this developing Alaskan industry. PMID:26131723

  13. Chemical risks associated with consumption of shellfish harvested on the north shore of the St. Lawrence River's lower estuary.

    PubMed

    Gagnon, Fabien; Tremblay, Thierry; Rouette, Justine; Cartier, Jacques-Franois

    2004-06-01

    Shellfish have the capacity to accumulate chemical contaminants found in their biotope and therefore present a potential risk for consumers. This study was conducted to assess the chemical risks associated with consumption of shellfish harvested on the north shore of the St. Lawrence River's lower estuary. A survey was carried out on 162 recreational harvesters, and shellfish were sampled for chemical contaminant analysis. We quantified 10 metals, 22 polycyclic aromatic hydrocarbons (PAHs), 14 polychlorinated biphenyls (PCBs), and 10 chlorinated pesticides. We subsequently evaluated cancer and noncancer risks for four consumption scenarios based on our survey results and published results. Soft-shell clams (Mya arenaria) were by far the most consumed shellfish species. Of the 56 selected contaminants, 36 were detected in the 23 homogenates of soft-shell clam meat. None of the contaminants found in the soft-shell clams were associated with intakes that exceed the main exposure limit recommendations proposed to prevent noncancer effects. However, several limits must be considered before drawing conclusions about the relative safety of shellfish consumption regarding this end point. Furthermore, inorganic arsenic and PCBs were present in sufficient concentrations to lead to cancer risks exceeding the level often considered acceptable for environmental exposure (1 x 10 (-4) to 1 x 10(-6)) in each of the four scenarios, even for the lowest observed scenario of 15 meals of soft-shell clams per year. PMID:15175177

  14. Development and evaluation of a RT-LAMP assay for rapid detection of hepatitis E virus from shellfish.

    PubMed

    Gao, Shenyang; Li, Dandan; Liu, Ying; Zha, Enhui; Wang, Shen; Li, Yonggang; Zhou, Tiezhong; Yue, Xiqing

    2016-03-01

    Hepatitis E virus (HEV) has becoming a well known zoonotic enteric pathogen and circulated widely inter human-animal-water-food. Generally, detection of the virus has relied on conventional reverse transcription-PCR (RT-PCR) and TaqMan/SYBR quantitative real-time RT-PCR (RT-qPCR), but these tools are usually disadvantages in time-consuming and expensive instruments required. In the present study, we report here on the development of a one-step single-tube reverse transcription-loop-mediated isothermal amplification (RT-LAMP) assay for rapid detection of HEV contamination in shellfish. The amplification is completed under the isothermal condition (63C) for 60min, and can be visually evaluated by staining at a time in about 1h. In addition, a total of 315 shellfish (80 Anadara granosa, 115 Scapharca subcrenata and 120 Ruditapes philippinarum) collected monthly from the Jinzhou coastal estuary of China Bohai gulf were investigated for HEV contamination by the RT-LAMP compared with a standard RT-qPCR. It was found that genotype 4 HEV was detected in all three species of shellfish sampled using the RT-LAMP assay and was in accordance with RT-qPCR detection of HEV in shellfish. Summarily, our results indicate that the RT-LAMP is a rapid, specific, sensitive and reliable method. This method offers a new tool for the routine monitoring of HEV contamination in shellfish or its harvesting waters in field. PMID:26741532

  15. Chemical risks associated with consumption of shellfish harvested on the north shore of the St. Lawrence River's lower estuary.

    PubMed Central

    Gagnon, Fabien; Tremblay, Thierry; Rouette, Justine; Cartier, Jacques-François

    2004-01-01

    Shellfish have the capacity to accumulate chemical contaminants found in their biotope and therefore present a potential risk for consumers. This study was conducted to assess the chemical risks associated with consumption of shellfish harvested on the north shore of the St. Lawrence River's lower estuary. A survey was carried out on 162 recreational harvesters, and shellfish were sampled for chemical contaminant analysis. We quantified 10 metals, 22 polycyclic aromatic hydrocarbons (PAHs), 14 polychlorinated biphenyls (PCBs), and 10 chlorinated pesticides. We subsequently evaluated cancer and noncancer risks for four consumption scenarios based on our survey results and published results. Soft-shell clams (Mya arenaria) were by far the most consumed shellfish species. Of the 56 selected contaminants, 36 were detected in the 23 homogenates of soft-shell clam meat. None of the contaminants found in the soft-shell clams were associated with intakes that exceed the main exposure limit recommendations proposed to prevent noncancer effects. However, several limits must be considered before drawing conclusions about the relative safety of shellfish consumption regarding this end point. Furthermore, inorganic arsenic and PCBs were present in sufficient concentrations to lead to cancer risks exceeding the level often considered acceptable for environmental exposure (1 x 10 (-4) to 1 x 10(-6)) in each of the four scenarios, even for the lowest observed scenario of 15 meals of soft-shell clams per year. PMID:15175177

  16. Application of the Pearl model to analyze fecal coliform data from conditionally approved shellfish harvest areas in seven Texas bays.

    PubMed

    Conte, F S; Ahmadi, A

    2014-09-01

    The U.S. National Shellfish Sanitation Program (NSSP) 14/43 standard states that conditionally approved shellfish growing areas must be closed for harvest when the geometric mean of fecal coliform concentration exceeds the NSSP limit of 14 most probable number (MPN)/100 mL, or the estimated 90th percentile of fecal coliform concentrations exceeds 43 MPN/100 mL for a five-tube test. The authors hypothesized that the NSSP 14/43 standard is not sufficient to protect the public from risks from consumption of biologically contaminated shellfish and the standard should be modified to 8/26 MPN/100 mL. To verify this hypothesis, the authors analyzed fecal coliform data from conditionally approved shellfish harvest areas of seven Texas bays using the Pearl sanitation model. Results showed that the shellfish closure rules mandated by the Texas Department of State Health Services actually enforced the "Pearl" limits of 8/26 MPN/100 mL, and not the NSSP limit of 14/43 MPN/100 mL. PMID:25226781

  17. FishMicrosat: a microsatellite database of commercially important fishes and shellfishes of the Indian subcontinent

    PubMed Central

    2013-01-01

    Background Microsatellite DNA is one of many powerful genetic markers used for the construction of genetic linkage maps and the study of population genetics. The biological databases in public domain hold vast numbers of microsatellite sequences for many organisms including fishes. The microsatellite data available in these data sources were extracted and managed into a database that facilitates sequences analysis and browsing relevant information. The system also helps to design primer sequences for flanking regions of repeat loci for PCR identification of polymorphism within populations. Description FishMicrosat is a database of microsatellite sequences of fishes and shellfishes that includes important aquaculture species such as Lates calcarifer, Ctenopharyngodon idella, Hypophthalmichthys molitrix, Penaeus monodon, Labeo rohita, Oreochromis niloticus, Fenneropenaeus indicus and Macrobrachium rosenbergii. The database contains 4398 microsatellite sequences of 41 species belonging to 15 families from the Indian subcontinent. GenBank of NCBI was used as a prime data source for developing the database. The database presents information about simple and compound microsatellites, their clusters and locus orientation within sequences. The database has been integrated with different tools in a web interface such as primer designing, locus finding, mapping repeats, detecting similarities among sequences across species, and searching using motifs and keywords. In addition, the database has the ability to browse information on the top 10 families and the top 10 species, through record overview. Conclusions FishMicrosat database is a useful resource for fish and shellfish microsatellite analyses and locus identification across species, which has important applications in population genetics, evolutionary studies and genetic relatedness among species. The database can be expanded further to include the microsatellite data of fishes and shellfishes from other regions and available information on genome sequencing project of species of aquaculture importance. PMID:24047532

  18. Uptake, transfer and elimination kinetics of paralytic shellfish toxins in common octopus (Octopus vulgaris).

    PubMed

    Lopes, Vanessa M; Baptista, Miguel; Repolho, Tiago; Rosa, Rui; Costa, Pedro Reis

    2014-01-01

    Marine phycotoxins derived from harmful algal blooms are known to be associated with mass mortalities in the higher trophic levels of marine food webs. Bivalve mollusks and planktivorous fish are the most studied vectors of marine phycotoxins. However, field surveys recently showed that cephalopod mollusks also constitute potential vectors of toxins. Thus, here we determine, for the first time, the time course of accumulation and depuration of paralytic shellfish toxins (PSTs) in the common octopus (Octopus vulgaris). Concomitantly, the underlying kinetics of toxin transfer between tissue compartments was also calculated. Naturally contaminated clams were used to orally expose the octopus to PSTs during 6 days. Afterwards, octopus specimens were fed with non-contaminated shellfish during 10 days of depuration period. Toxins reached the highest concentrations in the digestive gland surpassing the levels in the kidney by three orders of magnitude. PSTs were not detected in any other tissue analyzed. Net accumulation efficiencies of 42% for GTX5, 36% for dcSTX and 23% for C1+2 were calculated for the digestive gland. These compounds were the most abundant toxins in both digestive gland and the contaminated shellfish diet. The small differences in relative abundance of each toxin observed between the prey and the cephalopod predator indicates low conversion rates of these toxins. The depuration period was better described using an exponential decay model comprising a single compartment - the entire viscera. It is worth noting that since octopuses' excretion and depuration rates are low, the digestive gland is able to accumulate very high toxin concentrations for long periods of time. Therefore, the present study clearly shows that O. vulgaris is a high-potential vector of PSTs during and even after the occurrence of these toxic algal blooms. PMID:24316438

  19. Chlordane contamination in selected estuarine and coastal marine finfish and shellfish of New Jersey, USA.

    PubMed

    Kennish, M J; Ruppel, B E

    1996-01-01

    Analysis of chlordane contamination in selected finfish and shellfish species from estuarine and coastal marine waters of New Jersey, USA, indicates consistently highest organochlorine pesticide levels in samples from the north and northeast regions of the state. Gas chromatographic analysis of tissue samples from four finfish species (American eel, Anguilla rostrata; bluefish, Pomatomus saltatrix; striped bass, Morone saxatilis; and weakfish, Cynoscion regalis) and one shellfish species (blue crab, Callinectes sapidus) collected at 28 stations throughout the state during the 1986-1987 sampling period and 42 stations during the 1988-1991 sampling period revealed chlordane concentrations ranging from 5 to 2150 ppb wet weight (wet wt). Highest mean concentrations of chlordane (300 ppb wet wt) occurred in American eel from the Camden region, with secondary maxima (100 ppb wet wt) observed in the northeast region. Lower mean concentrations of chlordane (< 100 ppb wet wt) were recorded in tissue samples of other species collected elsewhere in the state. In general, the lowest levels of chlordane contamination (mean < 50 ppb wet wt) were found in samples from the south coast and Delaware regions. A major conclusion of this study is that some commercially and recreationally important finfish and shellfish species in New Jersey waters, especially those which are lipid-rich, have continued to accumulate chlordane from the environment long after restrictive regulations were first placed on its use in the US. The greatest impact of chlordane contamination is nearby metropolitan centers of the state (i.e., New York, Newark, Camden), although the total concentrations of chlordane in tissue samples from these areas are currently far less than the US Food and Drug Administration action level of 300 ppb wet wt. PMID:15093520

  20. The ecological role of bivalve shellfish aquaculture in the estuarine environment: A review with application to oyster and clam culture in West Coast (USA) estuaries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aquaculture is viewed as a potential mechanism to meet the growing demand for seafood around the world. The future of bivalve shellfish aquaculture in the U.S. hinges on sustainable practices on the part of industry and a more consistent regulatory regime. Bivalve shellfish aquaculture is a recent...

  1. Route of metabolization and detoxication of paralytic shellfish toxins in humans.

    PubMed

    Garca, Carlos; Barriga, Andrs; Daz, Juan Carlos; Lagos, Marcelo; Lagos, Nstor

    2010-01-01

    Paralytic shellfish toxins (PST) are a collection of over 26 structurally related imidazoline guanidinium derivatives produced by marine dinoflagellates and freshwater cyanobacteria. Glucuronidation of drugs by UDP-glucuronosyltransferase (UGT) is the major phase II conjugation reaction in mammalian liver. In this study, using human liver microsomes, the in vitro paralytic shellfish toxins oxidation and sequential glucuronidation are achieved. Neosaxitoxin (neoSTX), Gonyautoxin 3/2 epimers (GTX3/GTX2) and Saxitoxin (STX) are used as starting enzymatic substrates. The enzymatic reaction final product metabolites are identified by using HPLC-FLD and HPLC/ESI-IT/MS. Four metabolites from GTX3/GTX2 epimers precursors, three of neoSTX and two of STX are clearly identified after incubating with UDPGA/NADPH and fresh liver microsomes. The glucuronic-Paralytic Shellfish Toxins were completely hydrolysed by treatment with beta-glucuronidase. All toxin analogs were identified comparing their HPLC retention time with those of analytical standard reference samples and further confirmed by HPLC/ESI-IT/MS. Paralytic Shellfish Toxins (PST) were widely metabolized by human microsomes and less than 15% of the original PST, incubated as substrate, stayed behind at the end of the incubation. The apparent V(max) and Km formation values for the respective glucuronides of neoSTX, GTX3/GTX2 epimers and STX were determined. The V(max) formation values for Glucuronic-GTX3 and Glucuronic-GTX2 were lower than Glucuronic-neoSTX and Glucuronic-STX (6.8+/-1.9x10(-3); 8.3+/-2.8x10(-3) and 9.7+/-2.8x10(-3)pmol/min/mg protein respectively). Km of the glucuronidation reaction for GTX3/GTX2 epimers was less than that of glucuronidation of neoSTX and STX (20.2+/-0.12; 27.06+/-0.23 and 32.02+/-0.64microM respectively). In conclusion, these data show for the first time, direct evidence for the sequential oxidation and glucuronidation of PST in vitro, both being the initial detoxication reactions for the excretion of these toxins in humans. The PST oxidation and glucuronidation pathway showed here, is the hepatic conversion of its properly glucuronic-PST synthesized, and the sequential route of PST detoxication in human. PMID:19632259

  2. In situ detection of hepatitis A virus in cell cultures and shellfish tissues.

    PubMed Central

    Romalde, J L; Estes, M K; Szcs, G; Atmar, R L; Woodley, C M; Metcalf, T G

    1994-01-01

    An in situ transcription method was developed to detect hepatitis A virus RNA in both cell cultures and shellfish tissues. Radiolabeled cDNA copies were synthesized in situ by reverse transcriptase-directed transcription after annealing with a specific primer to the viral RNA. Both tritium (3H) and 35S were useful in the in situ transcription reaction, but the use of 3H resulted in a lower background and finer detail in the localization of viral particles. Application of the method to different organs of oysters which had bioaccumulated hepatitis A virus allowed the first in situ localization of the virus, specifically in stomach and hepatopancreatic tissues. Images PMID:8031087

  3. Bacterial influence on the production of paralytic shellfish toxins by dinoflagellated algae.

    PubMed

    Dantzer, W R; Levin, R E

    1997-10-01

    This study investigated the role of intracellular and extracellular bacteria in the production of paralytic shellfish toxins by dinoflagellated algal cells. Three strains of the toxic dinoflagellate species, Alexandrium tamarense, were purified by external bacteria using penicillin G (Pen. G) at levels of 500 and 1000 p.p.m. Levels of toxicity of the resulting purified dinoflagellate cultures were similar to those of the original strains contaminated with external bacteria, indicating that the external bacteria had no influence on toxicity. No bacterial colony forming units (cfu) arose from disruption of algal cells derived from penicillin-treated cultures, indicating that intracellular bacteria were not responsible for the toxicity of cultures. PMID:9351228

  4. Antibiotic Resistance Among Coliform and Fecal Coliform Bacteria Isolated from Sewage, Seawater, and Marine Shellfish

    PubMed Central

    Cooke, Marylyn D.

    1976-01-01

    Seawater and shellfish samples collected in the vicinity of a marine sewage outfall were examined for the incidence of antibiotic resistance among coliform and fecal coliform bacteria over a 2-year period. Seventy percent or more of these two groups of bacteria from both sources were resistant to one or more antibiotics. Forty-five percent of the isolates resistant to streptomycin or tetracycline were capable of transferring all or part of their resistance pattern to an antibiotic-susceptible strain of Escherichia coli K-12. PMID:779632

  5. Coliform risk assessment through use of the clam Anomalocardia brasiliana as animal sentinel for shellfish harvesting areas in Brazil's northeast.

    PubMed

    Lima-Filho, Jos Vitor; Interaminense, Juliana A; Batista, Jacqueline E; Vaz, Renata V; Ventura, Roberta F; Oliveira, Isabella B; Soares, Roberta B; Peixoto, Slvio M

    2015-08-01

    Outbreaks of food-borne diseases related to consumption of contaminated shellfish have been reported in many countries, but not in Brazil, possibly due to deficient reporting. Here we investigated the suitability of the clam Anomalocardia brasiliana as an animal sentinel for coliform monitoring in shellfish harvesting areas of Brazil's northeast. Samples of shellfish meats (40 clams per sample; n?=?8 per collection) were collected at random from April 2009 through March 2010 in the bay area of Mangue Seco (state of Pernambuco). The numbers of thermotolerant coliforms were analyzed through the most probable number technique, and these contamination levels were tentatively correlated with the precipitation recorded on the day of sampling or 24 to 48h beforehand. A. brasiliana shellfish meats from local retail shops (250g per sample/ n?=?3 per market) sold frozen were also investigated from August 2010 through June 2011. We found that the highest coliform contamination levels were correlated with recent rainfall events, limited to 24h before sampling. However, irrespective of the rainfall level, the mean contamination above the Brazilian legal threshold of shellfish harvesting areas ranged from 18.7 to 93.7% of samples analyzed monthly. Additionally, a large number of samples obtained from retail shops were also highly contaminated by coliforms during rainy periods, and therefore were not proper for human consumption. We conclude that A. brasiliana can be successfully used to monitor the contamination levels of coliforms in shellfish harvesting areas in Brazil's northeast coast. PMID:26243967

  6. Onboard screening dockside testing as a new means of managing paralytic shellfish poisoning risks in federally closed waters

    NASA Astrophysics Data System (ADS)

    DeGrasse, Stacey; Conrad, Stephen; DiStefano, Paul; Vanegas, Camilo; Wallace, David; Jensen, Pete; Hickey, J. Michael; Cenci, Florence; Pitt, Jaclyn; Deardorff, Dave; Rubio, Fernando; Easy, Dorothy; Donovan, Mary Anne; Laycock, Maurice; Rouse, Debbie; Mullen, John

    2014-05-01

    Paralytic shellfish poisoning (PSP) is the foodborne intoxication associated with the consumption of seafood contaminated with naturally occurring neurotoxins known as paralytic shellfish toxins. To protect public health from this potentially fatal syndrome, harvesting closures are implemented when toxins exceed the regulatory action level. Traditional monitoring programs established by state shellfish authorities allow for timely closures in state waters with minimal negative impacts on industry. However, such monitoring programs are not feasible in federal offshore waters given their distance from shore and the range of their spatial coverage. Thus innovative management strategies were investigated for these offshore resources. Georges Bank, an offshore resource with an estimated market value of more than 3 billion in Atlantic surfclams and ocean quahogs, has been closed to harvesting following a temporary ban in 1989 and a subsequent indefinite closure in 1990 due to the risk of PSP. As a means of managing this risk and allowing harvest of safe shellfish from this important resource, the Onboard Screening Dockside Testing Protocol (referred to as the Protocol) was developed by the US Food and Drug Administration (FDA), National Marine Fisheries Service (NMFS), state shellfish control authorities, and industry. The Protocol, which sets forth control measures to ensure product safety and public health protection, was endorsed by the Interstate Shellfish Sanitation Conference (ISSC) for pilot testing. Briefly, the pilot study Protocol required that (1) the fishing vessel receive a permit from NMFS to harvest in closed waters, (2) a miniμm of five shellfish samples per intended harvest lot be tested for PSP toxins onboard, and (3) harvesting only occur when the samples tested from the intended fishing area are negative using the Jellett Rapid Tests or Abraxis Shipboard ELISA kits. Finally, product landed under the Protocol was confirmed to be safe for consumption using the mouse bioassay (MBA) prior to its introduction into commerce. This paper presents data from the pilot study, with primary focus on the advantages and challenges of the field kits employed onboard compared to the dockside MBA, which has served as the longstanding regulatory method for PSP toxins. In 2010 alone, the successful pilot study resulted in the safe harvest of over 2.7 million worth of surfclams in an area that has otherwise been unavailable for decades. Due to the success of this pilot study, the Protocol was adopted into the National Shellfish Sanitation Program Model Ordinance as an approved marine biotoxin control strategy for use in federal waters at the 2011 ISSC Biennial Meeting. In January 2013 a portion of Georges Bank was reopened for the harvest of Atlantic surfclams and ocean quahogs to fishermen following the Protocol.

  7. Bioaccumulation Efficiency, Tissue Distribution, and Environmental Occurrence of Hepatitis E Virus in Bivalve Shellfish from France

    PubMed Central

    Grodzki, Marco; Schaeffer, Julien; Piquet, Jean-Cme; Le Saux, Jean-Claude; Chev, Julien; Ollivier, Joanna; Le Pendu, Jacques

    2014-01-01

    Hepatitis E virus (HEV), an enteric pathogen of both humans and animals, is excreted by infected individuals and is therefore present in wastewaters and coastal waters. As bivalve molluscan shellfish are known to concentrate viral particles during the process of filter feeding, they may accumulate this virus. The bioaccumulation efficiencies of oysters (Crassostrea gigas), flat oysters (Ostrea edulis), mussels (Mytilus edulis), and clams (Ruditapes philippinarum) were compared at different time points during the year. Tissue distribution analysis showed that most of the viruses were concentrated in the digestive tissues of the four species. Mussels and clams were found to be more sensitive to sporadic contamination events, as demonstrated by rapid bioaccumulation in less than 1 h compared to species of oysters. For oysters, concentrations increased during the 24-h bioaccumulation period. Additionally, to evaluate environmental occurrence of HEV in shellfish, an environmental investigation was undertaken at sites potentially impacted by pigs, wild boars, and human waste. Of the 286 samples collected, none were contaminated with hepatitis E virus, despite evidence that this virus is circulating in some French areas. It is possible that the number of hepatitis E viral particles discharged into the environment is too low to detect or that the virus may have a very short period of persistence in pig manure and human waste. PMID:24795382

  8. Aquaculture: Incorporating risk assessment and risk management into public policies on genetically modified finfish and shellfish

    SciTech Connect

    Hallerman, E.M.; Kapuscinski, A.R.

    1995-12-31

    Genetically modified finfish and shellfish pose economic benefits to aquaculture, but also pose ecological and genetic risks to ecosystems receiving such organisms. Realization of benefits with minimization of risks posed by a new technology can be addressed through the processes of risk assessment and risk management. Public policies adopted by individual countries will reflect differences in the outocme of risk assessment and risk management processes resulting from differences among the receiving ecosystems and sets of human values at issue. A number of countries and international institutions have begun development of policies for oversight of genetically modified aquatic organisms. In the United States, a working group commissioned by the U.S. Department of Agriculture incorporated risk assessment and risk management principles into draft performance standards for safely conducting research with genetically modified finfish and shellfish. The performance standards address research with a broad range of aquatic GMO`s and compliance is intended to be voluntary. In contrast, the Canadian policy mandates adherence to specified guidelines for experiments with transgenic aquatic organisms; establishment as national policy is expended soon.

  9. [Paralytic shellfish poisoning by Spondylus calcifer contaminated with Pyrodinium bahamense, Costa Rica, 1989-1990].

    PubMed

    Mata, L; Abarca, G; Marranghello, L; Vquez, R

    1990-06-01

    This paper describes an outbreak of paralytic shellfish poisoning (PSP), affecting human populations on the Pacific Coast of Costa Rica in October 1989. Numbness in arms, face and legs occurred 30 to 45 minutes after ingestion of the large clam Spondylus calcifer. Paralysis of legs and respiratory symptoms followed, often persisting for one week. Large amounts of the dinoflagellate Pyrodinium bahamense were found in the intestine of the mollusk. A toxin was detected in crude or filtered and heated macerates of intestine, muscle, mantle and hepatopancreas of S. calcifer, and to a lesser extent Tagelus sp., by injection of its crude or diluted extracts in white mice. The effects in mice consisted in paralysis and asphyxia generally leading to death in less than 5 minutes, compatible with saxitoxin. Mice were killed by the toxin in macerates diluted 1:100 to 1:1000. No toxin was detected in Anadara tuberculosa (Bivalvia) or in peneids. Prevention rests on intersectoral actions between state and private sectors in charge of fishing, distribution and marketing of shellfish, as well as on education of the population at large. PMID:2093952

  10. Evaluation of Passive Samplers as a Monitoring Tool for Early Warning of Dinophysis Toxins in Shellfish

    PubMed Central

    Pizarro, Gemita; Moroño, Ángeles; Paz, Beatriz; Franco, José M.; Pazos, Yolanda; Reguera, Beatriz

    2013-01-01

    From June 2006 to January 2007 passive samplers (solid phase adsorbing toxin tracking, SPATT) were tested as a monitoring tool with weekly monitoring of phytoplankton and toxin content (liquid chromatography–mass spectrometry, LC-MS) in picked cells of Dinophysis and plankton concentrates. Successive blooms of Dinophysis acuminata, D. acuta and D. caudata in 2006 caused a long mussel harvesting closure (4.5 months) in the Galician Rías (NW Spain) and a record (up to 9246 ng·g resin-week−1) accumulation of toxins in SPATT discs. Best fit of a toxin accumulation model was between toxin accumulation in SPATT and the product of cell densities by a constant value, for each species of Dinophysis, of toxin content (average) in picked cells. Detection of Dinophysis populations provided earlier warning of oncoming diarrhetic shellfish poisoning (DSP) outbreaks than the SPATT, which at times overestimated the expected toxin levels in shellfish because: (i) SPATT accumulated toxins did not include biotransformation and depuration loss terms and (ii) accumulation of toxins not available to mussels continued for weeks after Dinophysis cells were undetectable and mussels were toxin-free. SPATT may be a valuable environmental monitoring and research tool for toxin dynamics, in particular in areas with no aquaculture, but does not provide a practical gain for early warning of DSP outbreaks. PMID:24152559

  11. Improved method and test strategy for recovery of enteric viruses from shellfish.

    PubMed Central

    Metcalf, T G; Moulton, E; Eckerson, D

    1980-01-01

    An improved recovery method and testing strategy were devised for recovery of low numbers of enteric viruses from each of three commercially important shellfish species. Effective recovery of virus depended as much upon details of the test strategy adopted for use of the improved method with each species as on the method itself. The most important test details involved sample composition, pool size, and method of use of cell cultures. Recovery sensitivity measured permitted detection of 25 to 3 plaque-forming units of enteroviruses and 100 to 27 plaque-forming units of reovirus through their recovery in cell culture, with effectivenesses averaging 64 and 46%, respectively. Test samples prepared by the improved recovery method were virtually cytotoxicity free. Optimal recovery of virus on 45-cm2 cell culture monolayers was obtained with 1-ml inocula adsorbed for 2 h. The most effective recovery of virus from shellfish samples was made by a sequential adsorption procedure which allowed equal exposure of an entire sample to each of two or more cell cultures. Removal of nonviral contaminants from test samples by antibiotic treatment was preferable to the use of ether or membrane filtration procedures. PMID:6243902

  12. Building heat conservation and the feasibility of solar hot water heating in Long Island shellfish hatcheries

    SciTech Connect

    Berg, D.L.

    1980-01-01

    Temperature regulation is a vital component of any aquaculture system. Existing facilities can be retrofitted with extra insulation, waste heat recovery systems and in some cases, active solar water heating. Those aquaculture ventures that seek to raise organisms to market size under controlled conditions are currently hindered by high operating costs, including fuel. These outfits can also benefit from conservation and alternative energy technologies. In addition, the industry may be more willing to cultivate species normally restricted by climatic conditions if a less expensive source of heating were available. This report focuses on three of the bivalve shellfish aquaculture enterprises of Long Island, New York. In the 1978 to 1979 growing season, Long Island shellfish growers collectively burned over 50,000 gallons of heating oil to warm their hatchery waters and buildings. Since then, heating oil prices have doubled. Currently, some growers are limited by these fuel costs from beginning production earlier in the season. In this report, several heat conservation measures are discussed, and the feasibility of active solar hot water is examined.

  13. Detection of Cryptosporidium oocysts in green mussels (Perna viridis) from shell-fish markets of Thailand.

    PubMed

    Srisuphanunt, M; Wiwanitkit, Viroj; Saksirisampant, W; Karanis, P

    2009-09-01

    Mussels filter large volumes of water and can concentrate pathogenic organisms, which may act as potential vehicles of transmission to the consumer. A survey study was carried out to investigate the presence of Cryptosporidium protozoan parasites in green mussels (Perna viridis), the smussles pecies most destined for consumption in Thailand. In total, 56 samples were examined from Bangkok (n = 24) and Samut Prakan (n = 32) a wholesale shell-fish markets located at the mouth of the Chao Phraya River. The market for green mussels was closed to the mussel culture placed along the coastal line and this localization may have significant economical impact if the mussels' cultures are found contaminated. Cryptosporidium spp. oocysts were detected by the immunofluorescence antibody method (IFA) in 12.5% of the samples examined. The detection of Cryptosporidium oocysts in green mussels' population of Samut Prakan was higher (15.6%) than in Bangkok market (8.3%). These differences in positive samples from the two locations may be caused by physical, ecological and anthropogenic conditions. This could relay to different contamination levels of marine water by Cryptosporidium oocysts and consequently to contamination of harvested shellfish populations. The results demonstrate that the Cryptosporidium spp. oocysts were found indigenous in mussels from the coastal line of Thailand, indicating that mussels may act as a reservoir of Cryptosporidium foodborne infections for humans. PMID:19839271

  14. Radioactive contamination of fish, shellfish, and waterfowl exposed to Hanford effluents: Annual summaries, 1945--1972

    SciTech Connect

    Hanf, R.W.; Dirkes, R.L.; Duncan, J.P.

    1992-07-01

    The objective of the Hanford Environmental Dose Reconstruction Project (HEDR) is to estimate the potential radiation doses received by people living within the sphere of influence of the Hanford Site. A potential critical pathway for human radiation exposure is through the consumption of waterfowl that frequent onsite waste-water ponds or through eating of fish, shellfish, and waterfowl that reside in/on the Columbia River and its tributaries downstream of the reactors. This document summarizes information on fish, shellfish, and waterfowl radiation contamination for samples collected by Hanford monitoring personnel and offsite agencies for the period 1945 to 1972. Specific information includes the types of organisms sampled, the kinds of tissues and organs analyzed, the sampling locations, and the radionuclides reported. Some tissue concentrations are also included. We anticipate that these yearly summaries will be helpful to individuals and organizations interested in evaluating aquatic pathway information for locations impacted by Hanford operations and will be useful for planning the direction of future HEDR studies.

  15. Bioaccumulation efficiency, tissue distribution, and environmental occurrence of hepatitis E virus in bivalve shellfish from France.

    PubMed

    Grodzki, Marco; Schaeffer, Julien; Piquet, Jean-Cme; Le Saux, Jean-Claude; Chev, Julien; Ollivier, Joanna; Le Pendu, Jacques; Le Guyader, Franoise S

    2014-07-01

    Hepatitis E virus (HEV), an enteric pathogen of both humans and animals, is excreted by infected individuals and is therefore present in wastewaters and coastal waters. As bivalve molluscan shellfish are known to concentrate viral particles during the process of filter feeding, they may accumulate this virus. The bioaccumulation efficiencies of oysters (Crassostrea gigas), flat oysters (Ostrea edulis), mussels (Mytilus edulis), and clams (Ruditapes philippinarum) were compared at different time points during the year. Tissue distribution analysis showed that most of the viruses were concentrated in the digestive tissues of the four species. Mussels and clams were found to be more sensitive to sporadic contamination events, as demonstrated by rapid bioaccumulation in less than 1 h compared to species of oysters. For oysters, concentrations increased during the 24-h bioaccumulation period. Additionally, to evaluate environmental occurrence of HEV in shellfish, an environmental investigation was undertaken at sites potentially impacted by pigs, wild boars, and human waste. Of the 286 samples collected, none were contaminated with hepatitis E virus, despite evidence that this virus is circulating in some French areas. It is possible that the number of hepatitis E viral particles discharged into the environment is too low to detect or that the virus may have a very short period of persistence in pig manure and human waste. PMID:24795382

  16. BMAA in shellfish from two Portuguese transitional water bodies suggests the marine dinoflagellate Gymnodinium catenatum as a potential BMAA source.

    PubMed

    Lage, Sandra; Costa, Pedro Reis; Moita, Teresa; Eriksson, Johan; Rasmussen, Ulla; Rydberg, Sara Jonasson

    2014-07-01

    The neurotoxin ?-N-methylamino-l-alanine (BMAA) and its putative role in multiple neurodegenerative diseases have been intensely studied since 2005 when the toxin was discovered to be produced by worldwide-distributed cyanobacterial species inhabiting terrestrial, marine, brackish, and freshwater ecosystems. Recently, BMAA production was also associated with one eukaryotic group, namely, diatoms, raising questions about its production by other phytoplanktonic groups. To test for BMAA bioavailability in ecosystems where abundant phytoplanktonic blooms regularly occur, samples of filter-feeding shellfish were collected in two Portuguese transitional water bodies. BMAA content in cockles (Cerastoderma edule) collected weekly between September and November 2009 from Ria de Aveiro and at least once a month from May to November from Ria Formosa, fluctuated from 0.0790.055 to 0.3540.066?g/g DW and from below the limit of detection to 0.4340.110?g/g DW, respectively. Simultaneously to BMAA occurrence in cockles, paralytic shellfish toxins were detected in shellfish as a result of Gymnodinium catenatum blooms indicating a possible link between this marine dinoflagellate and BMAA production. Moreover, considerable high BMAA levels, 0.4570.186?g/g DW, were then determined in a laboratory grown culture of G. catenatum. This work reveals for the first time the presence of BMAA in shellfish from Atlantic transitional water bodies and consubstantiate evidences of G. catenatum as one of the main sources of BMAA in these ecosystems. PMID:24747603

  17. Vitamin D levels in fish and shellfish determined by liquid chromatography with ultraviolet detection and mass spectrometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vitamin D3 (cholecalciferol) levels were determined in finfish and shellfish using UV detection at 265nm (combined with auxiliary full scan UV detection) and selected ion monitoring (SIM) mass spectrometry (MS), using vitamin D2 (ergocalciferol) as an internal standard. Analysis of standard referen...

  18. UTILIZING SHELLFISH RESPONSES TO SET TARGET WATER QUALITY CONDITIONS FOR THE RESTORATION OF OYSTER REEFS IN THE CALOOSAHATCHEE ESTUARY, FLORIDA.

    EPA Science Inventory

    Volety, Aswani K., S.G. Tolley and James T. Winstead. 2002. Utilizing Shellfish Responses to Set Target Water Quality Conditions for the Restoration of Oyster Reefs in the Caloosahatchee Estuary, Florida. Presented at the International Workshop on Restoration of Benthic Invertebr...

  19. Higher Water Temperature and Incubation under Aerobic and Microaerobic Conditions Increase the Recovery and Diversity of Arcobacter spp. from Shellfish

    PubMed Central

    Levican, Arturo; Collado, Luis; Yustes, Clara; Aguilar, Carme

    2014-01-01

    Some Arcobacter species are considered emerging food-borne and waterborne pathogens, and shellfish have been suggested as one of their reservoirs. However, only a few studies have investigated the presence of Arcobacter in this kind of food. This study assesses the prevalence and diversity of Arcobacter spp. in shellfish by multiplex PCR (m-PCR) and culturing methods (under different atmospheric conditions) and evaluates the possible influence of environmental parameters (temperature, salinity, and harvesting bay). Arcobacter was detected by m-PCR and/or culturing in 61 (29.9%) of 204 shellfish samples. Of the positive samples by culturing, 41.1% were obtained under only aerobic incubation conditions, while 23.2% were obtained under only microaerobic conditions. Of 476 investigated isolates, 118 belonged to different enterobacterial repetitive intergenic consensus (ERIC)-PCR genotypes (strains) and to 11 different species. This study shows the highest diversity of Arcobacter species ever observed in samples from any origin. The most prevalent species was Arcobacter butzleri (60.2%), followed by Arcobacter molluscorum (21.2%). The prevalence of Arcobacter was significantly higher during the summer than in other seasons, being associated with an increase in water temperature. Results confirm that shellfish are a reservoir for a remarkable diversity of Arcobacter spp. PMID:24185851

  20. COASTAL*FISH user's guide--a finfish/shellfish information base for Mississippi Sound and Mobile Bay

    USGS Publications Warehouse

    Jones, B.; Benson, N.

    1982-01-01

    COASTAL *FISH is a computerized database that includes current information on spawning, nursery areas, migrations, distribution, and environmental requirements of finfish and shellfish. This User's Guide was prepared to access and query the finfish and shell fish database. It provides basic information required to query the database.

  1. Use of sodium dodecyl sulfate-polymyxin B-sucrose medium for isolation of Vibrio vulnificus from shellfish.

    PubMed

    Bryant, R G; Jarvis, J; Janda, J M

    1987-07-01

    The differential and selective sodium dodecyl sulfate-polymyxin B-sucrose medium (SPS) of Kitaura et al. (T. Kitaura, S. Doke, I. Azuma, M. Imaida, K. Miyano, K. Harada, and E. Yabuuchii, FEMS Microbiol. Lett. 17:205-209, 1983), which highlights alkylsulfatase activity, was evaluated for its potential use in the direct isolation and enumeration of Vibrio vulnificus from shellfish. V. vulnificus was detected by this method in six of nine shellfish samples collected from diverse geographic locales during the summer of 1986. Direct enumeration of V. vulnificus at 7.0 X 10(2) to 2.2 X 10(4) CFU/g of shellfish was achieved on SPS agar. All sample results were confirmed in parallel examinations by using conventional glucose-salt-Teepol (Shell Oil Co.) broth and alkaline peptone water enrichment with plating onto thiosulfate-citrate-bile salts-sucrose agar. Additionally, alkylsulfatase activity was evaluated in vitro for 97 strains representing 14 Vibrio spp. V. vulnificus and Vibrio cholerae-01 were the only species consistently found to possess this activity. The range of plating efficiencies for random V. vulnificus strains analyzed on SPS was 11 to 74% (mean, 39%). The use of SPS shows great promise for the study of shellfish and other environmental sources for V. vulnificus. PMID:3662506

  2. Shellfish Allergy

    MedlinePLUS

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  3. Climate relationships to fecal bacterial densities in Maryland shellfish harvest waters.

    PubMed

    Leight, A K; Hood, R; Wood, R; Brohawn, K

    2016-02-01

    Coastal states of the United States (US) routinely monitor shellfish harvest waters for types of bacteria that indicate the potential presence of fecal pollution. The densities of these indicator bacteria in natural waters may be related to climate in several ways, including through runoff from precipitation and survival related to water temperatures. The relationship between interannual precipitation and air temperature patterns and the densities of fecal indicator bacteria in shellfish harvest waters in Maryland's portion of the Chesapeake Bay was quantified using 34 years of data (1979-2013). Annual and seasonal precipitation totals had a strong positive relationship with average fecal coliform levels (R(2) = 0.69) and the proportion of samples with bacterial densities above the FDA regulatory criteria (R(2) = 0.77). Fecal coliform levels were also significantly and negatively related to average annual air temperature (R(2) = -0.43) and the average air temperature of the warmest month (R(2) = -0.57), while average seasonal air temperature was only significantly related to fecal coliform levels in the summer. River and regional fecal coliform levels displayed a wide range of relationships with precipitation and air temperature patterns, with stronger relationships in rural areas and mainstem Bay stations. Fecal coliform levels tended to be higher in years when the bulk of precipitation occurred throughout the summer and/or fall (August to September). Fecal coliform levels often peaked in late fall and winter, with precipitation peaking in summer and early fall. Continental-scale sea level pressure (SLP) analysis revealed an association between atmospheric patterns that influence both extratropical and tropical storm tracks and very high fecal coliform years, while regional precipitation was found to be significantly correlated with the Atlantic Multidecadal Oscillation and the Pacific North American Pattern. These findings indicate that management of shellfish harvest waters should account for changes in climate conditions and that SLP patterns may be particularly important for predicting years with extremely high levels of fecal coliforms. PMID:26689664

  4. Toxic marine microalgae and shellfish poisoning in the British isles: history, review of epidemiology, and future implications

    PubMed Central

    2011-01-01

    The relationship between toxic marine microalgae species and climate change has become a high profile and well discussed topic in recent years, with research focusing on the possible future impacts of changing hydrological conditions on Harmful Algal Bloom (HAB) species around the world. However, there is very little literature concerning the epidemiology of these species on marine organisms and human health. Here, we examine the current state of toxic microalgae species around the UK, in two ways: first we describe the key toxic syndromes and gather together the disparate reported data on their epidemiology from UK records and monitoring procedures. Secondly, using NHS hospital admissions and GP records from Wales, we attempt to quantify the incidence of shellfish poisoning from an independent source. We show that within the UK, outbreaks of shellfish poisoning are rare but occurring on a yearly basis in different regions and affecting a diverse range of molluscan shellfish and other marine organisms. We also show that the abundance of a species does not necessarily correlate to the rate of toxic events. Based on routine hospital records, the numbers of shellfish poisonings in the UK are very low, but the identification of the toxin involved, or even a confirmation of a poisoning event is extremely difficult to diagnose. An effective shellfish monitoring system, which shuts down aquaculture sites when toxins exceed regularity limits, has clearly prevented serious impact to human health, and remains the only viable means of monitoring the potential threat to human health. However, the closure of these sites has an adverse economic impact, and the monitoring system does not include all toxic plankton. The possible geographic spreading of toxic microalgae species is therefore a concern, as warmer waters in the Atlantic could suit several species with southern biogeographical affinities enabling them to occupy the coastal regions of the UK, but which are not yet monitored or considered to be detrimental. PMID:21645342

  5. Environmental links to interannual variability in shellfish toxicity in Cobscook Bay and eastern Maine, a strongly tidally mixed coastal region

    NASA Astrophysics Data System (ADS)

    Horecka, Hannah M.; Thomas, Andrew C.; Weatherbee, Ryan A.

    2014-05-01

    The Gulf of Maine experiences annual closures of shellfish harvesting due to the accumulation of toxins produced by dinoflagellates of the genus Alexandrium. Factors controlling the timing, location, and magnitude of these events in eastern Maine remain poorly understood. Previous work identified possible linkages between interannual variability of oceanographic variables and shellfish toxicity along the western Maine coastline but no such linkages were evident along the eastern Maine coast in the vicinity of Cobscook Bay, where strong tidal mixing tends to reduce seasonal variability in oceanographic properties. Using 21 years (1985-2005) of shellfish toxicity data, interannual variability in two metrics of annual toxicity, maximum magnitude and total annual toxicity, from stations in the Cobscook Bay region are examined for relationships to a suite of available environmental variables. Consistent with earlier work, no (or only weak) correlations were found between toxicity and oceanographic variables, even those very proximate to the stations such as local sea surface temperature. Similarly no correlations were evident between toxicity and air temperature, precipitation or relative humidity. The data suggest possible connections to local river discharge, but plausible mechanisms are not obvious. Correlations between toxicity and two variables indicative of local meteorological conditions, dew point and atmospheric pressure, both suggest a link between increased toxicity in these eastern Maine stations and weather conditions characterized by clearer skies/drier air (or less stormy/humid conditions). As no correlation of opposite sign was evident between toxicity and local precipitation, one plausible link is through light availability and its positive impact on phytoplankton production in this persistently foggy section of coast. These preliminary findings point to both the value of maintaining long-term shellfish toxicity sampling and a need for inclusion of weather variability in future modeling studies aimed at development of a more mechanistic understanding of factors controlling interannual differences in eastern Gulf of Maine shellfish toxicity.

  6. Paralytic shellfish poisoning toxin profile of mussels Perna perna from southern Atlantic coasts of Morocco.

    PubMed

    Abouabdellah, Rachid; Taleb, Hamid; Bennouna, Asmae; Erler, Katrin; Chafik, Abdeghani; Moukrim, Abdelatif

    2008-04-01

    During the monitoring programme of harmful algal blooms established along the south Atlantic coast of Morocco, a bimonthly determination of harmful algae and phycotoxins analysis in Perna perna was carried out from May 2003 to December 2004. Results of mouse bioassay (in organs and whole flesh) showed a seasonal evolution of paralytic shellfish poisoning (PSP) toxin. The mussel's contamination was associated with the occurrence in water of Alexandrium minutum. The PSP toxin profile obtained with high-performance liquid chromatography (HPLC/FD) revealed the dominance of gonyautoxins GTX2 and GTX3 and a minority of GTX1, GTX4 and saxitoxin (STX). This profile explains that the toxicity was mainly associated with A. minutum. PMID:18237757

  7. Trace metal residues in shellfish from Maryland waters, 1976-1980

    SciTech Connect

    Eisenberg, M.; Topping, J.J.

    1984-10-01

    Levels of seven heavy metal residues, arsenic, cadmium, chromium, copper, lead, mercury and zinc were monitored in samples of the American oyster (Crassostrea virginica), the soft shell clam (Mya arenaria), the hard shell clam (Mercenaria mercenaria) and the blue crab (Callinectes sapidus). The study was conducted from 1976 through 1980. In cases where the Food and Drug Administration has established action levels, mean and median yearly values were significantly below these levels. In cases where no action level exists, heavy metal residues in the shellfish samples were well below levels which are generally regarded as safe. No significant yearly trends in heavy metal residues were discovered. Apparent increases in arsenic levels merit further study. 22 references, 1 figure, 3 tables.

  8. Effects of “paralytic shellfish poison” on frog nerve and muscle

    PubMed Central

    Evans, M. H.

    1964-01-01

    A purified extract of toxic lamellibranchs, Saxidomus giganteus (Deshayes), containing “paralytic shellfish poison,” has been tested for its effects on conduction and contraction in frog nerve and muscle. The poison was very toxic and concentrations within the range 0.025 to 0.1 μg/ml. paralysed isolated muscle preparations, with abolition of the muscle action potential. The poison did not readily penetrate the perineurium, but in desheathed sciatic nerves the conduction of nerve impulses was rapidly blocked by concentrations of 0.05 to 0.1 μg/ml. There was no evidence that the poison had any specific curarizing action at the neuromuscular junction, and the paralysis was not accompanied by any appreciable depolarization of the muscle membrane. PMID:14211678

  9. Levels of perfluorinated compounds in raw and cooked Mediterranean finfish and shellfish.

    PubMed

    Vassiliadou, Irene; Costopoulou, Danae; Kalogeropoulos, Nick; Karavoltsos, Sotirios; Sakellari, Aikaterini; Zafeiraki, Effrosyni; Dassenakis, Manos; Leondiadis, Leondios

    2015-05-01

    Perfluorinated compounds (PFCs) were analyzed in several species of small Mediterranean fish and shellfish, all of which are popular in Greek diet. Analysis was conducted in raw samples and in samples cooked by the two ways preferred in Greek cuisine, i.e. fried in olive oil and grilled. PFCs above the detection limit were found in all raw samples except sardine, mussel and squid. The predominant PFC was PFOS (perfluorooctane sulfonate), the highest concentration of which was measured in picarel (20.4 ng g(-1) fresh weight). The PFOS values for the rest of the samples were between

  10. Mercury, arsenic, lead and cadmium in fish and shellfish from the Adriatic Sea.

    PubMed

    Juresa, D; Blanusa, M

    2003-03-01

    The aim was to measure concentrations of total mercury, total arsenic, lead and cadmium in common edible fresh fish and shellfish from various areas of the Adriatic Sea. Estimates of intake of these elements were made through seafood consumption by the general population. Samples were either wet digested for mercury and arsenic, or dry ashed for lead and cadmium analysis. Mercury was measured by cold vapour atomic absorption spectrometry (CV AAS) and arsenic, lead and cadmium by electrothermal atomic absorption spectrometry (ET AAS). Quality control procedures of analytical methods, which included analyses of dogfish muscle-certified reference material DORM-2, confirmed the acceptability of methods. The highest mercury and arsenic concentrations were found in hake (Merluccius merluccius) and the lowest in mackerel (Scomber scombrus). The respective values in hake were 0.373 +/- 0.075 and 23.3 +/- 3.6, and in mackerel 0.153 +/- 0.028 and 1.06 +/- 0.29 mg x kg(-1) fresh weight (mean +/- SD). Lead and cadmium concentrations were about 10 times higher in shellfish than in analysed fish. The highest lead and cadmium concentrations were found in mussel (Mytilus galloprovincialis) and the lowest in hake. Respective lead and cadmium values in mussel were 0.150 +/- 0.009 and 0.142 +/- 0.017, and in hake were 0.007 +/- 0.004 and 0.002 +/- 0.001 mg x kg(-1) fresh weight. The concentrations of analysed elements were below acceptable levels for human consumption set by the Croatian Ministry of Health, except for total arsenic. The estimated intake of those trace elements included in this study through seafood consumption by the general population did not exceed the provisional tolerable weekly intake recommended by the Joint FAO/WHO Expert Committee on Food Additives. PMID:12623648

  11. Long-Term Study of Vibrio parahaemolyticus Prevalence and Distribution in New Zealand Shellfish

    PubMed Central

    Hedderley, D.; Fletcher, G. C.

    2015-01-01

    The food-borne pathogen Vibrio parahaemolyticus has been reported as being present in New Zealand (NZ) seawaters, but there have been no reported outbreaks of food-borne infection from commercially grown NZ seafood. Our study determined the current incidence of V. parahaemolyticus in NZ oysters and Greenshell mussels and the prevalence of V. parahaemolyticus tdh and trh strains. Pacific (235) and dredge (21) oyster samples and mussel samples (55) were obtained from commercial shellfish-growing areas between December 2009 and June 2012. Total V. parahaemolyticus numbers and the presence of pathogenic genes tdh and trh were determined using the FDA most-probable-number (MPN) method and confirmed using PCR analysis. In samples from the North Island of NZ, V. parahaemolyticus was detected in 81% of Pacific oysters and 34% of mussel samples, while the numbers of V. parahaemolyticus tdh and trh strains were low, with just 3/215 Pacific oyster samples carrying the tdh gene. V. parahaemolyticus organisms carrying tdh and trh were not detected in South Island samples, and V. parahaemolyticus was detected in just 1/21 dredge oyster and 2/16 mussel samples. Numbers of V. parahaemolyticus organisms increased when seawater temperatures were high, the season when most commercial shellfish-growing areas are not harvested. The numbers of V. parahaemolyticus organisms in samples exceeded 1,000 MPN/g only when the seawater temperatures exceeded 19°C, so this environmental parameter could be used as a trigger warning of potential hazard. There is some evidence that the total V. parahaemolyticus numbers increased compared with those reported from a previous 1981 to 1984 study, but the analytical methods differed significantly. PMID:25616790

  12. Prevalence and Antimicrobial Resistance of Vibrio parahaemolyticus Isolated from Raw Shellfish in Poland.

    PubMed

    Lopatek, Magdalena; Wieczorek, Kinga; Osek, Jacek

    2015-05-01

    Vibrio parahaemolyticus is a marine bacterium recognized as an important cause of gastroenteritis in humans consuming contaminated shellfish. In recent years, increasing resistance to ampicillin and aminoglycosides has been observed among V. parahaemolyticus isolates. However, the first-line antimicrobials such as tetracyclines and fluoroquinolones remained highly effective against these bacteria. The aim of this study was to evaluate the occurrence of V. parahaemolyticus in live bivalve molluscs available on the Polish market and to determine the antimicrobial resistance of the recovered isolates. A total of 400 shellfish samples (mussels, oysters, clams, and scallops) from 2009 to 2012 were tested using the International Organization for Standardization standard 21872-1 method and PCR for the species-specific toxR gene. Antimicrobial susceptibility of the isolates was determined using a microbroth dilution method. V. parahaemolyticus was identified in 70 (17.5%) of the 400 samples, and the toxR gene was confirmed in 64 (91.4%) of these isolates. Most of the isolates were recovered from clams (31 isolates; 48.4% prevalence) followed by mussels (17 isolates; 26.6% prevalence). More V. parahaemolyticus-positive samples were found between May and September (22.7% prevalence) than between October and April (11.4% prevalence). Antibiotic profiling revealed that most isolates were resistant to ampicillin (56 isolates; 87.5%) and to streptomycin (45 isolates; 70.3%), but all of them were susceptible to tetracycline and chloramphenicol. Forty-one isolates (64.1%) were resistant to two or more antimicrobials; however, only one isolate (1.6%) was resistant to three antimicrobial classes. The antimicrobials used in treatment of human V. parahaemolyticus infection had high efficacy against the bacterial isolates tested. This study is the first concerning antibiotic resistance of V. parahaemolyticus isolates in Poland, and the results obtained indicate that these bacteria may pose a health risk to consumers. PMID:25951402

  13. Development of shellfish removing machine for large-diameter sea-water piping

    SciTech Connect

    Murakami, Seiichi; Nakazawa, Toyohiko; Watanabe, Seiji

    1996-08-01

    At nuclear and thermal power plants, the large amount of marine organisms that grow on the inside of condenser cooling, sea-water pipes, such as blue mussels and barnacles, significantly increases the pressure loss of the fluid in the pipes. This causes a deterioration in pumping efficiency and causes damage and corrosion to the paint coating on the inside of the pipes. These marine organisms must be removed, and this takes place by hand during each scheduled outage of the power plants. The working environment within these long lengths of large-diameter pipes is very harsh, requiring a great deal of time and physical labor to remove these organisms. Moreover, finding people to perform this task is becoming difficult. For these reasons. There has been a strong desire to mechanize this task. And this led to the development of a shellfish removing machine for these large-diameter sea-water pipes. The most important considerations in developing this machine were that the removal of the marine organisms be efficient and that the method of removal cause minimum damage to the coating on the inside of the pipes. Good results were obtained using a special cleaning brush that has a removing fixture attached to the end of a wire rope. After several application tests, the machine was used to remove shellfish from condenser cooling sea-water pipes during the sixth scheduled outage of the Japan Atomic Power Company`s Tsuruga No. 2 Unit in September, 1994. There, the capability and reliability of this machine were verified

  14. Detection of Cryptosporidium and Giardia in molluscan shellfish by multiplexed nested-PCR.

    PubMed

    Gmez-Couso, H; Freire-Santos, F; Amar, C F L; Grant, K A; Williamson, K; Ares-Mazs, M E; McLauchlin, J

    2004-03-15

    A multiplexed nested-PCR procedure (ABC-PCR) previously developed to detect Cryptosporidium spp. and Giardia duodenalis assemblages A and B in whole human faeces was applied to DNA extracted from filter-feeding molluscs. Species of Cryptosporidium and G. duodenalis were identified by restriction fragment analysis of the PCR products and by DNA sequencing. The extraction and ABC-PCR procedures were shown to be suitable for application to shellfish by amplification of specific target sequences using DNA from Cryptosporidium parvum genotype 2 and G. duodenalis assemblages A and B which were spiked into DNA extracted from mussels. Using 49 molluscan shellfish specimens (18 clam, 22 mussel and 9 oyster samples) from Spain, cryptosporidial oocysts were detected in 56% by immunofluorescence microscopy, and in 44% by ABC-PCR. For detection of Cryptosporidium, there was a significant association, but not total agreement, between the results of microscopy and PCR. G. duodenalis assemblage B was detected from one oyster sample by PCR. Amongst 38 specimens (20 mussel and 18 cockle samples) collected in the UK and tested by the ABC-PCR, G. duodenalis was not detected, and Cryptosporidium was detected in 11% of the samples. Overall, the 26 samples where Cryptosporidium was detected, C. hominis/C. parvum genotype 1 was detected in 1, C. parvum genotype 2 in 22, and the remaining three samples contained either sequences similar to C. parvum genotype 2 or heterogeneous mixtures of Cryptosporidium species. There was no significant association between the level of Escherichia coli detected by conventional microbiological methods and the presence of Cryptosporidium detected by ABC-PCR. PMID:14984775

  15. Lethal paralytic shellfish poisoning from consumption of green mussel broth, Western Samar, Philippines, August 2013

    PubMed Central

    Ramos, Ruth Alma; de los Reyes, Vikki Carr; Sucaldito, Ma Nemia; Tayag, Enrique

    2015-01-01

    Background In July 2013, the Philippines’ Event-Based Surveillance & Response Unit received a paralytic shellfish poisoning (PSP) report from Tarangnan, Western Samar. A team from the Department of Health conducted an outbreak investigation to identify the implicated source and risk factors in coastal villages known for green mussel production and exportation. Methods A case was defined as a previously well individual from Tarangan, Western Samar who developed gastrointestinal symptoms and any motor and/or sensory symptoms after consumption of shellfish from 29 June to 4 July 2013 in the absence of any known cause. The team reviewed medical records, conducted active case finding and a case-control study. Relatives of cases who died were interviewed. Sera and urine specimens, green mussel and seawater samples were tested for saxitoxin levels using high performance liquid chromatography. Results Thirty-one cases and two deaths were identified. Consumption of > 1 cup of green mussel broth was associated with being a case. Seawater sample was positive for Pyrodinium bahamense var. compressum and green mussel samples were positive for saxitoxin. Inspection revealed villagers practice open defecation and improper garbage disposal. Conclusion This PSP outbreak was caused by the consumption of the green mussel broth contaminated by saxitoxin. As a result of this outbreak, dinoflagellate and saxitoxin surveillance was established, and since the outbreak, there have been no harmful algal blooms event or PSP case reported since. A “Save Cambatutay Bay” movement, focusing on proper waste disposal practice and clean-up drives has been mobilized. PMID:26306212

  16. Climate change impacts on natural toxins in food production systems, exemplified by deoxynivalenol in wheat and diarrhetic shellfish toxins.

    PubMed

    van der Fels-Klerx, H J; Olesen, J E; Naustvoll, L-J; Friocourt, Y; Mengelers, M J B; Christensen, J H

    2012-01-01

    Climate change is expected to affect food and feed safety, including the occurrence of natural toxins in primary crop and seafood production; however, to date, quantitative estimates are scarce. This study aimed to estimate the impact of climate change effects on mycotoxin contamination of cereal grains cultivated in the terrestrial area of north west Europe, and on the frequency of harmful algal blooms and contamination of shellfish with marine biotoxins in the North Sea coastal zone. The study focused on contamination of wheat with deoxynivalenol, and on abundance of Dinophysis spp. and the possible relationship with diarrhetic shellfish toxins. The study used currently available data and models. Global and regional climate models were combined with models of crop phenology, mycotoxin prediction models, hydrodynamic models and ecological models, with the output of one model being used as input for the other. In addition, statistical data analyses using existing national datasets from the study area were performed to obtain information on the relationships between Dinophysis spp. cell counts and contamination of shellfish with diarrhetic shellfish toxins as well as on frequency of cereal cropping. In this paper, a summary of the study is presented, and overall conclusions and recommendations are given. Climate change projections for the years 2031-2050 were used as the starting point of the analyses relative to a preceding 20-year baseline period from which the climate change signal was calculated. Results showed that, in general, climate change effects lead to advanced flowering and harvest of wheat, and increased risk of contamination of wheat with deoxynivalenol. Blooms of dinoflagellates were estimated to occur more often. If the group of Dinophysis spp. behaves similarly to other flagellates in the future then frequency of harmful algal blooms of Dinophysis spp. may also increase, but consequences for contamination of shellfish with diarrhetic shellfish toxins are uncertain. Climate change will also have indirect effects on toxin contamination, which may be equally important. For example, the frequency of cropping of wheat and maize in north Europe was projected to increase under climate change, which will also increase the risk of contamination of the grains with deoxynivalenol. Risk managers are encouraged to consider the entire range of the predictions of climate change effects on food safety hazards, rather than median or average values only. Furthermore, it is recommended to closely monitor levels of mycotoxins and marine biotoxins in the future, in particular related to risky situations associated with favourable climatic conditions for toxin producing organisms. In particular, it is important to pay attention to the continuity of collecting the right data, and the availability and accessibility of databases. On a European level, it is important to stress the need for harmonisation of terminology and data collection. PMID:22891967

  17. A tentative national reference procedure for isolation and enumeration of Escherichia coli from bivalve molluscan shellfish by most probable number method.

    PubMed

    West, P A; Coleman, M R

    1986-12-01

    In the UK several quantitative methods exist for the examination of bivalve molluscan shellfish for sewage contamination. These methods include roll tubes, pour plates and most probable number (MPN) techniques, but there is no national standard method. A comparative study was made of the most commonly used methods for detection of Escherichia coli in bivalve shellfish. Schemes employing solid media, such as the roll tube and pour plate methods, underestimated faecal contamination in shellfish tissue compared with a liquid MPN multiple test-tube method using minerals-modified-glutamate broth (MMGB) as primary enrichment medium. The composition of MMGB apparently permits repair of sublethally injured cells of E. coli. Incorporation of resuscitation stages into the pour plate technique did not yield higher counts. A standardized MPN technique for examination of bivalve molluscan shellfish for E. coli content is proposed as a possible national reference procedure pending further collaborative assessment. PMID:3549664

  18. Most-probable-number loop-mediated isothermal amplification-based procedure enhanced with K antigen-specific immunomagnetic separation for quantifying tdh(+) Vibrio parahaemolyticus in molluscan Shellfish.

    PubMed

    Tanaka, Natsuko; Iwade, Yoshito; Yamazaki, Wataru; Gondaira, Fumio; Vuddhakul, Varaporn; Nakaguchi, Yoshitsugu; Nishibuchi, Mitsuaki

    2014-07-01

    Although thermostable direct hemolysin-producing (tdh(+)) Vibrio parahaemolyticus is the leading cause of seafood-borne gastroenteritis, the enumeration of tdh(+) V. parahaemolyticus remains challenging due to its low densities in the environment. In this study, we developed a most-probable-number (MPN)-based procedure designated A-IS(1)-LAMP, in which an immunomagnetic separation (IMS) technique targeting as many as 69 established K antigens and a loop-mediated isothermal amplification (LAMP) assay targeting the thermostable direct hemolysin (tdh) gene were applied in an MPN format. Our IMS employed PickPen, an eight-channel intrasolution magnetic particle separation device, which enabled a straightforward microtiter plate-based IMS procedure (designated as PickPen-IMS). The ability of the procedure to quantify a wide range of tdh(+) V. parahaemolyticus levels was evaluated by testing shellfish samples in Japan and southern Thailand, where shellfish products are known to contain relatively low and high levels of total V. parahaemolyticus, respectively. The Japanese and Thai shellfish samples showed, respectively, relatively low (< 3 to 11 MPN/10 g) and considerably higher (930 to 110,000 MPN/10 g) levels of tdh(+) V. parahaemolyticus, raising concern about the safety of Thai shellfish products sold to domestic consumers at local morning markets. LAMP showed similar or higher performance than conventional PCR in the detection and quantification of a wide range of tdh(+) V. parahaemolyticus levels in shellfish products. Whereas a positive effect of PickPen-IMS was not observed in MPN determination, PickPen-IMS was able to concentrate tdh(+) V. parahaemolyticus 32-fold on average from the Japanese shellfish samples at an individual tube level, suggesting a possibility of using PickPen-IMS as an optional tool for specific shellfish samples. The A-IS(1)-LAMP procedure can be used by any health authority in the world to measure the tdh(+) V. parahaemolyticus levels in shellfish products. PMID:24988012

  19. Methyl mercury concentrations in edible fish and shellfish from Dunedin, and other regions around the South Island, New Zealand.

    PubMed

    Sadhu, Ashish K; Kim, Jonathan P; Furrell, Hamish; Bostock, Ben

    2015-12-15

    Methyl mercury (MeHg) concentrations were determined in edible fish and shellfish available in local markets in Dunedin, New Zealand. While most of the fish species were sourced in Dunedin, some specimens of fish were also collected from waters off Picton, around Stewart Island and also off-shore of the South Island in the Puysegur and Subantarctic regions. The concentrations of MeHg were analysed in 25 different fish species and shellfish (103 muscle tissue samples). Total mercury (HgT) levels were also analysed in a few (n=12) selected fish samples. Most of the Hg was in the form of MeHg (≥96%). Higher MeHg concentrations were found in fish at higher trophic levels, particularly in predatory fish species such as ling, school shark, spiny dogfish and albacore tuna. Concentrations of MeHg in all samples ranged from 0.002 to 2.515μgMeHg/g. PMID:26478458

  20. Gas chromatography combined with mass spectrometry for the identification of organic sulfur compounds in shellfish and fish

    SciTech Connect

    Ogata, M.; Miyake, Y.

    1980-11-01

    The authors determined that the organic sulfur compounds usually contained in crude oil can be used as a marker of oil pollution in shellfish and fish. Short-necked clams and eels were maintained in a controlled laboratory environment in water with suspension of crude oil. Mass spectra and mass chromatograms of short-necked clam extract showed the presence of organic sulfur compounds. Capillary column gas chromatography-mass chromatograms of crude oil and extract from the soft body of a short-necked clam showed the presence of organic sulfur compounds. Besides sulfur components, various other compounds were contained in crude oil and short-necked clam. Mass chromatograms of crude oil and the extract from eel flesh showed the presence of alkyl benzothiophene, dibenzothiophene, naphthalene, and alkyl naphthalene. Data indicated that the organic sulfur compounds and polyaromatic compounds could serve as markers of oil pollution in shellfish and fish.

  1. Azaspiracid Shellfish Poisoning: A Review on the Chemistry, Ecology, and Toxicology with an Emphasis on Human Health Impacts

    PubMed Central

    Twiner, Michael J.; Rehmann, Nils; Hess, Philipp; Doucette, Gregory J.

    2008-01-01

    Azaspiracids (AZA) are polyether marine toxins that accumulate in various shellfish species and have been associated with severe gastrointestinal human intoxications since 1995. This toxin class has since been reported from several countries, including Morocco and much of western Europe. A regulatory limit of 160 μg AZA/kg whole shellfish flesh was established by the EU in order to protect human health; however, in some cases, AZA concentrations far exceed the action level. Herein we discuss recent advances on the chemistry of various AZA analogs, review the ecology of AZAs, including the putative progenitor algal species, collectively interpret the in vitro and in vivo data on the toxicology of AZAs relating to human health issues, and outline the European legislature associated with AZAs. PMID:18728760

  2. Trading green backs for green crabs: evaluating the commercial shellfish harvest at risk from European green crab invasion

    PubMed Central

    Mach, Megan E; Chan, Kai MA

    2014-01-01

    Nonnative species pose a threat to native biodiversity and can have immense impacts on biological communities, altering the function of ecosystems. How much value is at risk from high-impact invasive species, and which parameters determine variation in that value, constitutes critical knowledge for directing both management and research, but it is rarely available. We evaluated the value of the commercial shellfish harvest that is at risk in nearshore ecosystems of Puget Sound, Washington State, USA, from the invasive European green crab, Carcinus maenas. We assessed this value using a simple static ecological model combined with an economic model using data from Puget Sound’s shellfish harvest and revenue and the relationship between C. maenas abundance and the consumption rate of shellfish. The model incorporates a range in C. maenas diet preference, calories consumed per year, and crab densities. C. maenas is likely to prey on commercially harvested hardshell clams, oysters, and mussels, which would likely reduce additional revenue from processing and distribution, and the number of jobs associated with these fisheries. The model results suggest possible revenue losses of these shellfish ranging from $1.03-23.8 million USD year -1 (2.8-64% losses), with additional processing and distribution losses up to $17.6 million USD and 442 job positions each year associated with a range of plausible parameter values. The broad range of values reflects the uncertainty in key factors underlying impacts, factors that are highly variable across invaded regions and so not knowable a priori. However, future research evaluating species invasions can reduce the uncertainty of impacts by characterizing several key parameters: density of individuals, number of arrivals, predation and competition interactions, and economic impacts. This study therefore provides direction for research to inform more accurate estimates of value-at-risk, and suggests substantial motivation for strong measures to prevent, monitor, and manage the possible invasion of C. maenas. PMID:25408891

  3. Water pollution: Uptake of heavy metals by shellfish and marine plants. (Latest citations from Oceanic abstracts). Published Search

    SciTech Connect

    Not Available

    1994-02-01

    The bibliography contains citations concerning heavy metal contamination of shellfish and marine plants. Toxicity levels and the long term effects on the ecology of the marine environment are discussed. The growth rate of marine life as a function of metal concentration and the long term effects on the food chain are also considered. (Contains 250 citations and includes a subject term index and title list.)

  4. Multidetection of paralytic, diarrheic, and amnesic shellfish toxins by an inhibition immunoassay using a microsphere-flow cytometry system.

    PubMed

    Fraga, Mara; Vilario, Natalia; Louzao, M Carmen; Rodrguez, Paula; Campbell, Katrina; Elliott, Christopher T; Botana, Luis M

    2013-08-20

    The presence of paralytic shellfish poisoning (PSP), diarrheic shellfish poisoning (DSP), and amnesic shellfish poisoning (ASP) toxins in seafood is a severe and growing threat to human health. In order to minimize the risks of human exposure, the maximum content of these toxins in seafood has been limited by legal regulations worldwide. The regulated limits are established in equivalents of the main representatives of the groups: saxitoxin (STX), okadaic acid (OA), and domoic acid (DA), for PSP, DSP, and ASP, respectively. In this study a multidetection method to screen shellfish samples for the presence of these toxins simultaneously was developed. Multiplexing was achieved using a solid-phase microsphere assay coupled to flow-fluorimetry detection, based on the Luminex xMap technology. The multidetection method consists of three simultaneous competition immunoassays. Free toxins in solution compete with STX, OA, or DA immobilized on the surface of three different classes of microspheres for binding to specific monoclonal antibodies. The IC50 obtained in the buffer was similar in single- and multidetection: 5.6 1.1 ng/mL for STX, 1.1 0.03 ng/mL for OA, and 1.9 0.1 ng/mL for DA. The sample preparation protocol was optimized for the simultaneous extraction of STX, OA, and DA with a mixture of methanol and acetate buffer. The three immunoassays performed well with mussel and scallop matrixes displaying adequate dynamic ranges and recovery rates (around 90% for STX, 80% for OA, and 100% for DA). This microsphere-based multidetection immunoassay provides an easy and rapid screening method capable of detecting simultaneously in the same sample three regulated groups of marine toxins. PMID:23859142

  5. Trading green backs for green crabs: evaluating the commercial shellfish harvest at risk from European green crab invasion.

    PubMed

    Mach, Megan E; Chan, Kai Ma

    2013-01-01

    Nonnative species pose a threat to native biodiversity and can have immense impacts on biological communities, altering the function of ecosystems. How much value is at risk from high-impact invasive species, and which parameters determine variation in that value, constitutes critical knowledge for directing both management and research, but it is rarely available. We evaluated the value of the commercial shellfish harvest that is at risk in nearshore ecosystems of Puget Sound, Washington State, USA, from the invasive European green crab, Carcinus maenas. We assessed this value using a simple static ecological model combined with an economic model using data from Puget Sound's shellfish harvest and revenue and the relationship between C. maenas abundance and the consumption rate of shellfish. The model incorporates a range in C. maenas diet preference, calories consumed per year, and crab densities. C. maenas is likely to prey on commercially harvested hardshell clams, oysters, and mussels, which would likely reduce additional revenue from processing and distribution, and the number of jobs associated with these fisheries. The model results suggest possible revenue losses of these shellfish ranging from $1.03-23.8 million USD year (-1) (2.8-64% losses), with additional processing and distribution losses up to $17.6 million USD and 442 job positions each year associated with a range of plausible parameter values. The broad range of values reflects the uncertainty in key factors underlying impacts, factors that are highly variable across invaded regions and so not knowable a priori. However, future research evaluating species invasions can reduce the uncertainty of impacts by characterizing several key parameters: density of individuals, number of arrivals, predation and competition interactions, and economic impacts. This study therefore provides direction for research to inform more accurate estimates of value-at-risk, and suggests substantial motivation for strong measures to prevent, monitor, and manage the possible invasion of C. maenas. PMID:25408891

  6. Application of rapid test kits for the determination of Diarrhetic Shellfish Poisoning (DSP) toxins in bivalve molluscs from Great Britain.

    PubMed

    Johnson, Sarah; Harrison, Keith; Turner, Andrew D

    2016-03-01

    Four commercial rapid screening methods for Diarrhetic Shellfish Poisoning were applied to the analysis of naturally contaminated shellfish samples from GB. The performance of each kit was assessed through comparison with the reference LC-MS/MS method on a range of both positive and negative bivalve mollusc samples. A quantitative PP2A protein phosphatase assay was the only assay to show the complete absence of false negative results. It showed a fair correlation with LC-MS/MS but with an overall overestimation of sample toxicity together with some indications of interference from sample matrix, most notably within oyster species. A quantitative competitive ELISA also gave a fair correlation with LC-MS/MS, with no evidence of toxicity overestimation and with a good response to samples containing little or no DST's, although one false negative was recorded. The two qualitative lateral flow assays both provided a high percentage agreement with the LC-MS/MS results and there were no indications of false positive results, although both kits also returned one false negative result. The false negative results returned by the three assays were all associated with samples containing high proportions of DTX2, a toxin which occurs commonly in UK shellfish. The scanners provided with both lateral flow assays were easy to use and the provision of numerical results enables a semi-quantitative assessment of toxicities which would significantly benefit the end user. Whilst key differences exist between the proposed assays they are all rapid, do not require expensive equipment and the work here has provided some evidence for suitability for indicative testing for some species of bivalve shellfish from GB. Further work is required however using a larger number of test kit batches on a greater number of samples, particularly for those containing high proportions of DTX2. PMID:26792713

  7. Thirty years - Alexandrium fundyense cyst, bloom dynamics and shellfish toxicity in the Bay of Fundy, eastern Canada

    NASA Astrophysics Data System (ADS)

    Martin, Jennifer L.; LeGresley, Murielle M.; Hanke, Alex R.

    2014-05-01

    Sediment and water samples were collected for Alexandrium fundyense spatial and temporal distribution and abundance at more than 120 locations throughout the Bay of Fundy during the summers and winters of 1980-1984. These broad surveys have been repeated at various times through the past 30 years, with more regular sampling since 2004. In addition, A. fundyense abundance has been monitored at several locations within the Bay of Fundy at weekly intervals from April to November and monthly during the remaining months since 1988. Paralytic Shellfish Poisoning (PSP) toxins in shellfish (notably Mya arenaria) have also been monitored at multiple locations in the Bay of Fundy since 1943. The datasets were examined to determine relationships and roles between overwintering resting cysts, bloom initiation, bloom decline, motile cell dispersal and A. fundyense motile populations and resulting shellfish toxicity since 1980. Cysts are widely dispersed throughout the Bay of Fundy in the offshore, inshore and intertidal zones with the largest deposits located in the offshore in silt/clay sediments to the east and north of Grand Manan Island at depths of 60-180 m. Results show that there is a constant stable source of cysts in the Bay of Fundy with highest concentrations of cysts (9780 cysts cm-3) observed in 2010 and highest concentrations of A. fundyense motile cells (18×106 cells L-1) observed in 1980. Interannual changes in abundance in A. fundyense populations, resting cysts and the temporal trends in M. arenaria toxicity are discussed. Results show that there was no relationship between the abundance of overwintering cysts and the magnitude of A. fundyense blooms. The offshore seed beds appear to be relatively constant in cyst density among most years and serve as an important source for the motile cells that lead to initiation of major blooms and resulting shellfish toxicity throughout the Bay of Fundy.

  8. Water pollution: Uptake of heavy metals by shellfish and marine plants. (Latest citations from Oceanic Abstracts). Published Search

    SciTech Connect

    Not Available

    1992-07-01

    The bibliography contains citations concerning heavy metal contamination of shellfish and marine plants. Toxicity levels and the long term effects on the ecology of the marine environment are discussed. The growth rate of marine life as a function of metal concentration and the long term effects on the food chain are also considered. (Contains 250 citations and includes a subject term index and title list.)

  9. Seasonal abundance and composition of finfish and shellfish seeds inmangroves of Gangolli estuary, off south-west coast of India.

    PubMed

    Rajesh, K M; Thomas, Sujitha; Dineshbabu, A R; PrathibhaRohit; Sridhara, B; Nataraja, G D

    2015-11-01

    The composition and seasonal abundance of the fin and shellfish seeds in mangrove areas of Gangoli estuary were studied for one year from January to December, 2013. Monthly day time sampling was conducted with a rectangular dragnet of 75 m2 length having 5 mm mesh size. The mean monthly density was highest in January (Avg. of 12,996/haul) and lowest during May (Avg. of 859/haul). Thirty species of fish, four species of shrimps and two species of crabs belonging to 26 families were recorded during the study. Ambasis sp., Feneropenaeus indicus, Etroplus suratensis,Leognathus sp., Liza sp., Stolephorus vaganensis, Hemiramphus sp., Terapon sp. and Gerres sp. were the most abundant species/taxa. A total of 10 commercially important species comprising F. indicus, Etroplus suratensis, Liza sp., Gerres sp.,Siganus sp., Lutjanus russei, Macrobrachium rosenbergii, Lutjanus argentimaculatus, Sillago sp. and Penaeus monodon constituted 8.5% (April, 2013) to 93.7% (October, 2013) with an average of 37.2% of the total fish and shellfish seeds. Higher Species diversity (H') and Species richness (D) was recorded during January. The result of the present investigation gives an insight of the abundance and seasonality of commercially important fish and shellfish seeds, which may facilitate the brackishwater fish farmers to exploitthe seeds more pragmatically for their culture practice. PMID:26688975

  10. Capillary electrophoresis-based immunoassay for the determination of brevetoxin-B in shellfish using electrochemical detection.

    PubMed

    Zhang, Xiaowei; Zhang, Zhaoxiang

    2013-02-01

    Neurotoxic shellfish poisoning is a significant food-borne disease caused by potent cyclic polyether toxins (brevetoxins) that accumulate in the flesh of shellfish. Here we report a new procedure for brevetoxin analysis by capillary electrophoresis-based immunoassay (CE-IA) with electrochemical (EC) detection. In this method, after the competitive immunoreaction in liquid phase, the horseradish peroxidase (HRP)-labeled antigen and the bound enzyme-labeled complex were separated and then the system of HRP catalyzing H(2)O(2)-o-aminophenol reaction was adopted. The limits of detection (signal-to-noise = 3) was determined to be 0.1 ng/mL. Intra-day relative standard deviations (RSD, n = 5) for migration time and peak area were 3.6 and 4.5%, respectively. Inter-day RSD was 6.9 and 7.8% for migration time and peak area, respectively. The CE-IA with EC detection provides a sensitive analytical approach, not previously available, for the determination of brevetoxin-B in shellfish samples. PMID:22781183

  11. Confirmation by LC-MS/MS of azaspiracids in shellfish from the Portuguese north-western coast.

    PubMed

    Vale, Paulo; Bire, Ronel; Hess, Philipp

    2008-06-15

    The search for azaspiracids (AZAs) in shellfish on the Portuguese coast started in 2002, but the presence of these toxins could not be demonstrated until the summer of 2006. Analysis by liquid-chromatography-tandem mass spectrometry (LC-MS/MS) allowed the confirmation of AZA2 as a dominant compound, followed by AZA1, in blue mussel (Mytilus galloprovincialis), common cockle (Cerastoderma edule), clams (Venerupis senegalensis, Ruditapes decussatus), razor clam (Solen marginatus) and oyster (Crassostrea spp). Traces of AZA3 were found only in blue mussel. Total levels of AZA1-3 determined in the whole flesh by LC-MS/MS ranged from 1.6 to 6.1 microg/kg. The finding of low levels of AZAs since 2002 suggests a low risk level when compared with the highest risks posed by diarrhetic shellfish poisoning (DSP) and paralytic shellfish poisoning (PSP) toxins. However, the limited number of years studied might generate a misleading conclusion. The contamination with PSP is an example, as no contamination occurred for an extended period of time between 1996 and 2004, despite high levels having occurred outside this period. Thus, there appears overall a moderate likelihood of occurrence of AZAs in the range that may be relevant to consumers. PMID:18471847

  12. Determination of toxic elements (mercury, cadmium, lead, tin and arsenic) in fish and shellfish samples. Risk assessment for the consumers.

    PubMed

    Olmedo, P; Pla, A; Hernndez, A F; Barbier, F; Ayouni, L; Gil, F

    2013-09-01

    Although fish intake has potential health benefits, the presence of metal contamination in seafood has raised public health concerns. In this study, levels of mercury, cadmium, lead, tin and arsenic have been determined in fresh, canned and frozen fish and shellfish products and compared with the maximum levels currently in force. In a further step, potential human health risks for the consumers were assessed. A total of 485 samples of the 43 most frequently consumed fish and shellfish species in Andalusia (Southern Spain) were analyzed for their toxic elements content. High mercury concentrations were found in some predatory species (blue shark, cat shark, swordfish and tuna), although they were below the regulatory maximum levels. In the case of cadmium, bivalve mollusks such as canned clams and mussels presented higher concentrations than fish, but almost none of the samples analyzed exceeded the maximum levels. Lead concentrations were almost negligible with the exception of frozen common sole, which showed median levels above the legal limit. Tin levels in canned products were far below the maximum regulatory limit, indicating that no significant tin was transferred from the can. Arsenic concentrations were higher in crustaceans such as fresh and frozen shrimps. The risk assessment performed indicated that fish and shellfish products were safe for the average consumer, although a potential risk cannot be dismissed for regular or excessive consumers of particular fish species, such as tuna, swordfish, blue shark and cat shark (for mercury) and common sole (for lead). PMID:23792415

  13. Mathematical model for viral depuration kinetics in shellfish: an useful tool to estimate the risk for the consumers.

    PubMed

    Polo, David; Feal, Xabier; Romalde, Jess L

    2015-08-01

    Enteric virus depuration from shellfish is a complex biological process that may be influenced by biological properties of the mollusc and/or virus species. On the basis of previous experimental data, a mathematical model was developed to characterize the kinetics of viral elimination during the depuration process. The experimental data consisted on twenty depuration trials, each with 60 kg of Manila clams (Venerupis philippinarum) and mediterranean mussels (Mytilus galloprovincialis) previously subjected to bioaccumulation with HAV or MNV-1 (as a surrogate for human norovirus), that were performed in an experimental depuration system during 7 days. It was observed that although viral loads decay along depuration, a residual viral load remains at the end of the process suggesting a decomposition of viral load in a diluted load (susceptible of depuration) and a non-diluted load (unavailable to depurate). The model yielded a general equation, which can predict the viral load at any depuration time knowing the specific filtration rate, dependent on the bivalve species, and specific viral properties. The mathematical model can be combined with quantitative risk assessment calculations to determine the safety of the depurated shellfish, which can be very helpful not only for shellfish producers but also to public health authorities. PMID:25846934

  14. Characterization of organochlorine pesticides, brominated flame retardants and dioxin-like compounds in shellfish and eel from Fiji.

    PubMed

    Lal, Vincent; Bridgen, Phil; Votadroka, Waisea; Raju, Rupantri; Aalbersberg, William

    2014-09-01

    This article gives an overview of a range of persistent organic pollutant chemical levels in shellfish (Batissa violacea and Anadara antiquata) species and eel (Gymnothorax flavimarginatus) from Fiji. As there is limited data in published literature to date, this paper reports first data on a range of persistent organic pollutants and highlights the more prominent POP chemicals present in marine biota in Fiji. A significant number of POP chemicals were detected (e.g. 17 PCDD/PCDF, 12dl-PCBs, organochlorine pesticides and brominated flame retardants), the concentrations found were generally low (e.g. parts per billion level). The low levels of contamination are indicative of a low input from long range and short-range transport as well as few local point sources. Also concentrations of POPs in eel and shellfish from Fiji are low in comparison to wild species in other regions and are within acceptable limits for POP chemicals in fish and fishery products set by the European Union. It describes also results of early studies on basic POPs levels in shellfish in several Pacific Island Countries, which generally show relatively low levels. PMID:24568747

  15. Nutrients and Chemical Pollutants in Fish and Shellfish. Balancing Health Benefits and Risks of Regular Fish Consumption.

    PubMed

    Domingo, Jos L

    2014-12-01

    Dietary patterns and lifestyle factors are clearly associated with at least five of the ten leading causes of death, including coronary heart disease, certain types of cancer, stroke, non-insulin dependent diabetes mellitus, and atherosclerosis. Concerning specifically fish and seafood consumption, its beneficial health effects in humans are clearly supported by an important number of studies performed in the last 30years. These studies have repeatedly linked fish consumption, especially those species whose contents in omega-3 fatty acids are high, with healthier hearts in the aging population. The nutritional benefits of fish and seafood are also due to the content of high-quality protein, vitamins, as well as other essential nutrients. However, a number of studies, particularly investigations performed in recent years, have shown that the unavoidable presence of environmental contaminants in fish and shellfish can also mean a certain risk for the health of some consumers. While prestigious international associations as the American Heart Association have recommended eating fish at least two times (two serving a week), based on our own experimental results, as well as in results from other laboratories, we cannot be in total agreement with that recommendation. Although a regular consumption of most fish and shellfish species should not mean adverse health effects for the consumers, the specific fish and shellfish species consumed, the frequency of consumption, as well as the meal size, are essential issues for adequately balancing the health benefits and risks of regular fish consumption. PMID:25486051

  16. A graphene-based electrochemical competitive immunosensor for the sensitive detection of okadaic acid in shellfish

    NASA Astrophysics Data System (ADS)

    Eissa, Shimaa; Zourob, Mohammed

    2012-11-01

    A novel graphene-based voltammetric immunosensor for sensitive detection of okadaic acid (OA) was developed. A simple and efficient electrografting method was utilized to functionalize graphene-modified screen-printed carbon electrodes (GSPE) by the electrochemical reduction of in situ generated 4-carboxyphenyl diazonium salt in acidic aqueous solution. Next, the okadaic acid antibody was covalently immobilized on the carboxyphenyl modified graphene electrodes via carbodiimide chemistry. Square wave voltammetry (SWV) was used to investigate the stepwise assembly of the immunosensor. A competitive assay between OA and a fixed concentration of okadaic acid-ovalbumin conjugate (OA-OVA) for the immobilized antibodies was employed for the detection of okadaic acid. The decrease of the [Fe(CN)6]3-/4- reduction peak current in the square wave voltammetry for various concentrations of okadaic acid was used for establishing the calibration curve. A linear relationship between the SWV peak current difference and OA concentration was obtained up to ~5000 ng L-1. The developed immunosensor allowed a detection limit of 19 ng L-1 of OA in PBS buffer. The matrix effect studied with spiked shellfish tissue extracts showed a good percentage of recovery and the method was also validated with certified reference mussel samples.A novel graphene-based voltammetric immunosensor for sensitive detection of okadaic acid (OA) was developed. A simple and efficient electrografting method was utilized to functionalize graphene-modified screen-printed carbon electrodes (GSPE) by the electrochemical reduction of in situ generated 4-carboxyphenyl diazonium salt in acidic aqueous solution. Next, the okadaic acid antibody was covalently immobilized on the carboxyphenyl modified graphene electrodes via carbodiimide chemistry. Square wave voltammetry (SWV) was used to investigate the stepwise assembly of the immunosensor. A competitive assay between OA and a fixed concentration of okadaic acid-ovalbumin conjugate (OA-OVA) for the immobilized antibodies was employed for the detection of okadaic acid. The decrease of the [Fe(CN)6]3-/4- reduction peak current in the square wave voltammetry for various concentrations of okadaic acid was used for establishing the calibration curve. A linear relationship between the SWV peak current difference and OA concentration was obtained up to ~5000 ng L-1. The developed immunosensor allowed a detection limit of 19 ng L-1 of OA in PBS buffer. The matrix effect studied with spiked shellfish tissue extracts showed a good percentage of recovery and the method was also validated with certified reference mussel samples. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr32146g

  17. The seasonality of fecal coliform bacteria pollution and its influence on closures of shellfish harvesting areas in Mississippi Sound.

    PubMed

    Chigbu, Paulinus; Gordon, Scott; Tchounwou, Paul B

    2005-08-01

    Runoff from agricultural lands and farm animal feedlots is one of the major sources of fecal coliforms in surface waters, and fecal coliform (FC) bacteria concentrations tend to vary with season because of seasonal variations in climatic factors. However, El Nio--Southern Oscillation (ENSO) events may affect the extent and patterns of seasonality in FC levels in coastal waters. Water quality monitoring data for shellfish management collected during El Nio (1990, 1992, 1997), and La Nia (1999, 2000) years were analyzed to evaluate the extent to which these events influenced Pearl River stage, and bacterial levels, water temperature, and salinity in the western part of Mississippi Sound. Models to predict FC levels in relation to various environmental factors were also developed. In 1990, 1992 and 1997, FC geometric mean counts peaked in late winter (January/February) reaching 120 MPN (February 1990), 165 MPN (January 1992), and 86 MPN (January 1997), and then decreased considerably during spring and summer (1.2 - 19 MPN). Thereafter, FC abundance increased slightly in fall and early winter (1.9 - 24 MPN). Fecal coliform abundance during the 2000 La Nia year was much lower (1.0 -10.3 MPN) than in 1992 (1.2 - 165 MPN), and showed no seasonal pattern from January to August, perhaps due to the relative scarcity of rainfall in 2000. In 1995 (ENSO neutral year), peak geometric mean FC count (46 MPN) was lower than during El Nio years and occurred in early spring (March). The seasonal and between year variations in FC levels determined the number of days during which the conditionally approved shellfish growing area was opened for harvesting shellfish. For example, from January to April 1997, the area was not opened for shellfish harvesting, whereas in 2000, the number of days during which the area was opened ranged from 6 - 27 (January to April) to 24 - 26 (October to December). ENSO events thus influenced the extent and timing of the peak levels of fecal coliforms in Mississippi Sound. Models consisting of one or more of the variables: Pearl River stage, water temperature, and salinity were developed to predict FC concentrations in the Sound. The model parameter(s) explained 56 to 91% of the variations in FC counts. Management of shellfish in Mississippi Sound can be improved by utilizing information on the forecasted three to seven years occurrence of ENSO events. In addition, since Pearl River stage was the most important variable predicting FC concentration in the Sound, a study of the levels and sources of FC bacteria in the river, especially the middle and lower sections, is needed for developing a management plan for reducing FC bacteria pollution in the Sound. PMID:16705840

  18. A graphene-based electrochemical competitive immunosensor for the sensitive detection of okadaic acid in shellfish.

    PubMed

    Eissa, Shimaa; Zourob, Mohammed

    2012-12-01

    A novel graphene-based voltammetric immunosensor for sensitive detection of okadaic acid (OA) was developed. A simple and efficient electrografting method was utilized to functionalize graphene-modified screen-printed carbon electrodes (GSPE) by the electrochemical reduction of in situ generated 4-carboxyphenyl diazonium salt in acidic aqueous solution. Next, the okadaic acid antibody was covalently immobilized on the carboxyphenyl modified graphene electrodes via carbodiimide chemistry. Square wave voltammetry (SWV) was used to investigate the stepwise assembly of the immunosensor. A competitive assay between OA and a fixed concentration of okadaic acid-ovalbumin conjugate (OA-OVA) for the immobilized antibodies was employed for the detection of okadaic acid. The decrease of the [Fe(CN)(6)](3-/4-) reduction peak current in the square wave voltammetry for various concentrations of okadaic acid was used for establishing the calibration curve. A linear relationship between the SWV peak current difference and OA concentration was obtained up to ~5000 ng L(-1). The developed immunosensor allowed a detection limit of 19 ng L(-1) of OA in PBS buffer. The matrix effect studied with spiked shellfish tissue extracts showed a good percentage of recovery and the method was also validated with certified reference mussel samples. PMID:23108911

  19. Neutralizing effect of hemolymph from the shore crab, Thalamita crenata, on paralytic shellfish toxins.

    PubMed

    Lin, Huajuan; Zhang, Chaohua; Liao, Jianmeng; Yang, Feng; Zhong, Saiyi; Jiang, Peihong; Chen, Xiao; Nagashima, Yuji

    2015-06-01

    Several species of crabs are resistant to paralytic shellfish toxins (PSTs) and/or pufferfish toxin, tetrodotoxin, regardless of toxification by the toxins. The shore crab Thalamita crenata, which inhabits Leizhou Peninsula, China, is tolerant to PST toxicity, and the hemolymph has neutralizing effects against the lethal activity of PST. In the present study, we investigated the PST neutralizing factors in the hemolymph from T.crenata and successfully separated PST-binding proteins by PST-ligand affinity chromatography. The neutralization factors, obtained in the fraction with a molecular weight over 10kDa by ultrafiltration, were susceptible to proteases such as alcalase, animal complex proteases, pancreatin, and papain. The PST-binding protein had high dose-dependent neutralization effects on PST toxicity. The PST-binding activity of the protein was stable at 25C and then decreased with an increase in temperature; heating at 65C for 60min eliminated the initial activity by two-thirds. The PST-binding activity was strongly inhibited in the presence of Mg(2+) and Ca(2+), but not Na(+) and K(+). The PST-binding capability of the protein differed among PST components in descending order of neosaxitoxin, gonyautoxins 1 and 4, saxitoxin, and gonyautoxins 2 and 3, suggesting a structure-activity relationship in PST binding. PMID:25797318

  20. Helminth parasites of fish and shellfish from the Santa Gilla Lagoon in southern Sardinia, Italy.

    PubMed

    Culurgioni, J; Sabatini, A; De Murtas, R; Mattiucci, S; Figus, V

    2014-12-01

    An extensive survey of helminth parasites in fish and shellfish species from Santa Gilla, a brackish water lagoon in southern Sardinia (western Mediterranean), resulted in the identification of 69 helminth parasite taxa and/or species from 13 fish species (n=515) and seven bivalve species (n=2322) examined between September 2001 and July 2011. The list summarizes information on the helminth parasites harboured by fish and molluscs contained in the available literature. Digenea species (37), both adults and larvae, dominated the parasite fauna, whereas Cestoda were the least represented class (three species). Monogenea, Nematoda and Acanthocephala were present with 17, 6 and 6 species, respectively, which were mainly adults. The most widespread parasite species was the generalist Contracaecum rudolphii A (Nematoda). Other species, such as the Haploporidae and Ascocotyle (Phagicola) spp. 1 and 2 (Digenea), showed a high family specificity in Mugilidae. Importantly, the study recorded the occurrence of potential zoonotic agents, such as Heterophyes heterophyes, Ascocotyle (Phagicola) spp. and C. rudolphii A, the latter two reaching the highest indices of infection in the highly marketed fish grey mullet and sea bass, respectively. The highest parasite richness was detected in Dicentrarchus labrax, which harboured 17 helminth species, whereas the lowest value was observed in Atherina boyeri, infected by only three species. The list includes the first geographical record in Italian coastal waters of Robinia aurata and Stictodora sawakinensis, and 30 reports of new host-parasite complexes, including the larval stages of Ascocotyle (Ascocotyle) sp. and Southwellina hispida in D. labrax. PMID:23790066

  1. Fate of Human Noroviruses in Shellfish and Water Impacted by Frequent Sewage Pollution Events.

    PubMed

    Campos, Carlos J A; Avant, Justin; Gustar, Nicole; Lowther, James; Powell, Andy; Stockley, Louise; Lees, David N

    2015-07-21

    Knowledge of the fate of human noroviruses (NoV) in the marine environment is key to better controlling shellfish-related NoV gastroenteritis. We quantified NoV and Escherichia coli in sewage from storm tank discharges and treated effluent processed by a UV-disinfection plant following activated sludge treatment and studied the fate of these microorganisms in an oyster harvesting area impacted by frequent stormwater discharges and infrequent freshwater discharges. Oyster monitoring sites were positioned at intervals downstream from the wastewater treatment works (WwTW) outfall impacting the harvesting area. The decay rates of NoV in oysters as a function of the distance from the outfall were less rapid than those for E. coli that had concentrations of NoV of the same order of magnitude and were over 7 km away from the outfall. Levels of E. coli in oysters from more tidally influenced areas of the estuary were higher around high water than around low water, whereas tidal flows had no influence on NoV contamination in the oysters. The study provides comparative data on the contamination profiles and loadings of NoV and E. coli in a commercial oyster fishery impacted by a WwTW. PMID:26125679

  2. Predator lipids induce paralytic shellfish toxins in bloom-forming algae

    PubMed Central

    Selander, Erik; Kubanek, Julia; Hamberg, Mats; Andersson, Mats X.; Cervin, Gunnar; Pavia, Henrik

    2015-01-01

    Interactions among microscopic planktonic organisms underpin the functioning of open ocean ecosystems. With few exceptions, these organisms lack advanced eyes and thus rely largely on chemical sensing to perceive their surroundings. However, few of the signaling molecules involved in interactions among marine plankton have been identified. We report a group of eight small molecules released by copepods, the most abundant zooplankton in the sea, which play a central role in food webs and biogeochemical cycles. The compounds, named copepodamides, are polar lipids connecting taurine via an amide to isoprenoid fatty acid conjugate of varying composition. The bloom-forming dinoflagellate Alexandrium minutum responds to pico- to nanomolar concentrations of copepodamides with up to a 20-fold increase in production of paralytic shellfish toxins. Different copepod species exude distinct copepodamide blends that contribute to the species-specific defensive responses observed in phytoplankton. The signaling system described here has far reaching implications for marine ecosystems by redirecting grazing pressure and facilitating the formation of large scale harmful algal blooms. PMID:25918403

  3. [Microphytobenthos assemblage mapping by spatial visible-infrared remote sensing in a shellfish ecosystem].

    PubMed

    Mlder, Vona; Launeau, Patrick; Barill, Laurent; Rinc, Yves

    2003-04-01

    The aim of this work is to assess the use of (SPOT) multispectral visible infrared remote sensing to study microphytobentos assemblages in a shellfish ecosystem (Bay of Bourgneuf, France). SPOT satellite images (acquired at low tide in spring or autumn between 1986 and 1998) were calibrated using in situ radiometric data, and the normalised vegetation index (NDVI) obtained from these images showed microphytobenthos on bay mudflats. Proliferation was mainly along a north-south strip, essentially localised around the +2 m isobath and covering a surface area of 19 to 25% of the total mudflat area studied (420 to 550 ha). Three factors seem to be responsible for the spatial structure of the assemblages: bathymetry, nutrient input from the Falleron River and its channel, and the location of oyster-farming areas. Although spatial and spectral resolutions of multispectral remote sensing data have certain limitations, this approach opens up a new field of application for hyperspectral remote sensing, particularly for synoptic mapping of biomass distribution. PMID:12876890

  4. Shellfish Dredging Pushes a Flexible Avian Top Predator out of a Marine Protected Area

    PubMed Central

    van Gils, Jan A; Piersma, Theunis; Dekinga, Anne; Spaans, Bernard; Kraan, Casper

    2006-01-01

    There is a widespread concern about the direct and indirect effects of industrial fisheries; this concern is particularly pertinent for so-called “marine protected areas” (MPAs), which should be safeguarded by national and international law. The intertidal flats of the Dutch Wadden Sea are a State Nature Monument and are protected under the Ramsar convention and the European Union's Habitat and Birds Directives. Until 2004, the Dutch government granted permission for ~75% of the intertidal flats to be exploited by mechanical dredgers for edible cockles (Cerastoderma edule). Here we show that dredged areas belonged to the limited area of intertidal flats that were of sufficient quality for red knots (Calidris canutus islandica), a long-distance migrant molluscivore specialist, to feed. Dredging led to relatively lower settlement rates of cockles and also reduced their quality (ratio of flesh to shell). From 1998 to 2002, red knots increased gizzard mass to compensate for a gradual loss in shellfish quality, but this compensation was not sufficient and led to decreases in local survival. Therefore, the gradual destruction of the necessary intertidal resources explains both the loss of red knots from the Dutch Wadden Sea and the decline of the European wintering population. This study shows that MPAs that do not provide adequate protection from fishing may fail in their conservation objectives. PMID:17105350

  5. DDT contamination in selected estuarine and coastal marine finfish and shellfish of New Jersey.

    PubMed

    Kennish, M J; Ruppel, B E

    1996-08-01

    Analysis of DDT contamination in selected finfish and shellfish species from estuarine and coastal marine waters of New Jersey (USA) reveals consistently highest organochlorine pesticide levels in samples from the north and northeast regions of the state. The mean concentrations of DDT and its metabolites, DDE and DDD, in bluefish, striped bass, weakfish, and blue crabs collected at 27 stations throughout the state between 1988 and 1991 ranged from <25 to >300 microg/kg wet weight (wet wt). Gas chromatographic analysis of 175 tissue samples from these four species showed that the highest levels of DDTs (DDT plus DDE and DDD), exceeding 300 microg/kg wet wt, occurred in blue crabs (hepatopancreas) from the Hudson-Newark-Raritan Bay complex in the northeast region. Lower mean concentrations of DDTs (<200 microg/kg wet wt) were recorded in tissue samples of these species from all other regions of the state. The lowest levels of DDT contamination (mean <110 microg/kg wet wt) were found in samples from the south coast region. The greatest impact of DDT contamination is nearby metropolitan areas of the state, although the total concentrations of DDT in tissue samples from these areas are far less than the U.S. Food and Drug Administration action level of 5,000 microg/kg wet wt for this contaminant. PMID:8781078

  6. In vitro bioaccessibility of the marine biotoxin okadaic acid in shellfish.

    PubMed

    Braga, Ana C; Alves, Ricardo N; Maulvault, Ana L; Barbosa, Vera; Marques, António; Costa, Pedro R

    2016-03-01

    Okadaic acid (OA) and their derivatives are marine toxins responsible for the human diarrhetic shellfish poisoning (DSP). To date the amount of toxins ingested in food has been considered equal to the amount of toxins available for uptake by the human body. In this study, the OA fraction released from the food matrix into the digestive fluids (bioaccessibility) was assessed using a static in vitro digestion model. Naturally contaminated mussels (Mytilus galloprovincialis) and donax clams (Donax sp.), collected from the Portuguese coast, containing OA and dinophysistoxin-3 (DTX3) were used in this study. Bioaccessibility of OA total content was 88% and 75% in mussels and donax clams, respectively. Conversion of DTX3 into its parent compound was verified during the simulated digestive process and no degradation of these toxins was found during the process. This is the first study assessing the bioaccessibility of OA-group toxins in naturally contaminated seafood. This study provides relevant new data that can improve and lead to more accurate food safety risk assessment studies concerning these toxins. PMID:26783635

  7. Influence of upwelling relaxation on dinoflagellates and shellfish toxicity in Ria de Vigo, Spain

    NASA Astrophysics Data System (ADS)

    Fraga, Santiago; Anderson, Donald M.; Bravo, Isabel; Reguera, Beatriz; Steidinger, Karen A.; Yentsch, Clarice M.

    1988-10-01

    Outbreaks of paralytic shellfish poisoning (PSP) along the north-west coast of Spain have become a serious threat to the extensive mussel farming industry in that region over the last decade. During the summer, high phytoplankton productivity is supported by the sustained upwelling of nutrient-rich deep water into the rias. An episode of PSP in the autumn of 1985 in Ria de Vigo coincided with the sudden appearance, rapid numerical increase, and dominance of two chain-forming dinoflagellates, Gymnodinium catenatum and Protogonyaulax affinis. Field data suggest that warm offshore surface water was transported into the ria as the summer upwelling ceased. This occurred when winds changed from northerly (upwelling favourable) to southerly or westerly (upwelling unfavourable); the injected water contained established populations of oceanic and neritic dinoflagellates. The simultaneous appearance and dominance of two dinoflagellates that form long chains leads us to speculate that the small-scale downwelling of water within the ria favoured efficient swimmers among the phytoplankton. These data not only implicate these two species as possible sources of the PSP toxins in local mussels, but they also suggest the feasibility of developing a bloom prediction capability for some dinoflagellate species based in part on an upwelling index that can indicate when offshore surface waters might be forced into the rias.

  8. Paralytic shellfish toxins, including deoxydecarbamoyl-STX, in wild-caught Tasmanian abalone (Haliotis rubra).

    PubMed

    Harwood, D Tim; Selwood, Andrew I; van Ginkel, Roel; Waugh, Craig; McNabb, Paul S; Munday, Rex; Hay, Brenda; Thomas, Krista; Quilliam, Michael A; Malhi, Navreet; Dowsett, Natalie; McLeod, Catherine

    2014-11-01

    For the first time wild-caught Tasmanian abalone, Haliotis rubra, have been reported to contain paralytic shellfish toxins (PSTs). This observation followed blooms of the toxic dinoflagellate Gymnodinium catenatum. No illnesses were reported, but harvesting restrictions were enforced in commercial areas. Abalone were assayed using HPLC-FLD methodology based on AOAC official method 2005.06. An uncommon congener, deoxydecarbamoyl-STX (doSTX), was observed in addition to regulated PSTs as unassigned chromatographic peaks. A quantitative reference material was prepared from contaminated Tasmanian abalone viscera and ampouled at 54.2 μmol/L. The LD50 of doSTX via intraperitoneal injection was 1069 nmol/kg (95% confidence limits 983-1100 nmol/kg), indicating it is nearly 40 times less toxic than STX. A toxicity equivalence factor of 0.042 was generated using the mouse bioassay. Levels of PSTs varied among individuals from the same site, although the toxin profile remained relatively consistent. In the foot tissue, STX, decarbamoyl-STX and doSTX were identified. On a molar basis doSTX was the dominant congener in both foot and viscera samples. The viscera toxin profile was more complex, with other less toxic PST congeners observed and was similar to mussels from the same site. This finding implicates localised dinoflagellate blooms as the PST source in Tasmanian abalone. PMID:25157803

  9. Temporal variation in biodeposit organic content and sinking velocity in long-line shellfish culture

    NASA Astrophysics Data System (ADS)

    Ren, Lihua; Zhang, Jihong

    2016-01-01

    We measured the organic content and sinking velocities of biodeposits from two scallop species (Chlamys farreri, Patinopecten yessoensis) and abalone (Haliotis discus hannai) that were cultured on suspended long-lines. Measurements were conducted every two months from April 2010 to February 2011. The shellfish were divided into three size groups (small, middle, and big sizes). At each sample point, we assessed biodeposit organic content, average sinking velocity, the frequency distribution of sinking velocities, and the correlation between organic content and sinking velocity. The organic content of biodeposits varied significantly among months (P < 0.05) and the pattern of change varied among species. Sinking velocities varied significantly, ranging from <0.5 cm/s to >1.9 cm/s. The sinking velocities of biodeposits from C. farreri and P. yessoensis were 0.5-1.5 cm/s and from H. discus hannai were <0.7 cm/s. The organic content was significantly negatively correlated to the sinking velocity of biodeposits in C. farreri (P < 0.001) and P. yessoensis (P < 0.05).

  10. Depuration of shellfish by irradiation: Final technical report, October 1, 1987--March 31, 1989

    SciTech Connect

    Beghian, L.E.; Mallett, J.C.

    1989-01-01

    Studies by the University of Lowell Radiation Laboratory and the US National Marine Fisheries Service N.E. Laboratory in Gloucester, MA on softshelled clams (Mya arenaria) demonstrated the effectiveness of low to medium doses of Cobalt 60 source gamma irradiation in the inactivation of Escherichia coli, Salmonella typhimurium, Staphylococcus aureus and Streptococcus faecalis. Post-irradiation survival and organoleptic studies when extended to hardshelled clams (Mercinaria mercenaria) and American oysters (Crassostrea virginica) showed no significant decline in consumer qualities or 6 day post irradiation survival in oysters at doses of up to 3.0 kGy. The capacities of the American oyster to sustain relatively high doses of gamma irradiation were demonstrated by 6 day post-exposure survivorship values of greater than 90% for samples receiving 3.0, 5.0 and 7.0 kGy. Initial studies of inactivation of Polio I virus and a simian rotavirus (SA-11) was conducted in both hardshelled clams and oysters. Of greatest interest was the behavior of Hepatitis A virus (HAV), in live, irradiated shellfish. The average log decrement value for HAV in oysters was calculated at 2.0 kGy. From these data it appears that doses of up to 2 kGy can be applied to: reduce or eliminate bacterial pathogens, reduce the infectivity of human viral pathogens by one or more orders of magnitude, and preserve market qualities of longevity, appearance, odor, taste and texture. 23 refs., 11 figs., 3 tabs.

  11. Metal concentrations in Maryland`s shellfish: 1970s--1990s

    SciTech Connect

    Murphy, D.L.

    1995-12-31

    Maryland has been monitoring arsenic, cadmium, chromium, copper, lead, mercury and zinc in bivalve shellfish from state waters since the 1960s. The primary bivalve species monitored in Maryland waters are the oyster, Crassostrea virginica and the softshell clam, Mya arenaria. These data have been evaluated for temporal trends. In order to insure that temporal evaluations be based upon data produced using comparable analytical methods, the time period evaluated is not the same for all analytes. For example, while most evaluations are for the period 1974 through 1994, arsenic data were evaluated for the period 1980 through 1994. Data for oyster tissue indicate declines in levels of mercury, cadmium, arsenic, copper and zinc on the order of 70--90%. The major portion of these reductions occurred prior to 1985. These declines are evident from data collected from Maryland`s lower eastern shore, a relatively remote area, as well as from waters closer to larger population centers. Past detection levels for lead and chromium were insufficiently low to detect temporal changes.

  12. Predictive mechanistic bioenergetics to model habitat suitability of shellfish culture in coastal lakes

    NASA Astrophysics Data System (ADS)

    Rinaldi, A.; Montalto, V.; Manganaro, A.; Mazzola, A.; Mirto, S.; Sanfilippo, M.; Sar, G.

    2014-05-01

    Quantitative tools based on mechanistic modelling of functional traits able to enhance the sustainability of aquaculture and most other human activities (i.e. reducing the likelihood of detrimental impacts optimising productions), are especially important factors in the decision to site aquaculture facilities in coastal lakes, ponds and lagoons and, in the case of detrimental impact, to adopt mitigation measures. We tested the ability of mechanistic functional trait based models to predict life history traits of cultivable shellfish in shallow coastal lakes. Dynamic Energy Budget (DEB) models were run to generate spatially explicit predictions of Mytilus galloprovincialis life history (LH) traits (e.g. body size and fecundity). Using fortnightly data of food supply and hourly data of body temperatures, and exploiting the power of mechanistic rules, we estimated the amount of faeces ejected by a fixed quantity of organisms cultivated in two shallow Southern Mediterranean (Sicily) lakes. These differed in terms of temperature and food density, implying large differences in life history traits of mussels in the two study areas. This information could help facilitate the selection of sites where environmental conditions are more suitable for aquaculture and contextually compatible with sustainability. The validation exercise obtained by comparing the predicted and observed data was nearly consistent. Therefore, a mechanistic functional traits-based model seems able to capture the link between habitat characteristics and functional traits of organisms, delineating the fundamental portion of an ecological niche, the possibility of predicting LH traits and potential ecological applications in the management of natural coastal resources.

  13. Intertidal Concentrations of Microplastics and Their Influence on Ammonium Cycling as Related to the Shellfish Industry.

    PubMed

    Cluzard, Melanie; Kazmiruk, Tamara N; Kazmiruk, Vasily D; Bendell, L I

    2015-10-01

    Microplastics are ubiquitous within the marine environment. The last 10 years have seen research directed at understanding the fate and effect of microplastics within the marine environment; however, no studies have yet addressed how concentrations of these particles could affect sedimentary processes such as nutrient cycling. Herein we first determine the concentration and spatial distribution of microplastics within Baynes Sound, a key shellfish-growing area within coastal British Columbia (BC). We also determined sediment grain size and % organic matter (OM) such that we could relate spatial patterns in sediment microplastic concentrations to sedimentary processes that determine zones of accretion and erosion. Using field-determined concentrations of microplastics, we applied laboratory microcosms studies, which manipulated sediment concentrations of microplastics, OM, and bivalves to determine the influence of sediment microplastics on ammonium cycling within intertidal sediments. Concentrations of microplastics determined within the intertidal sediment varied spatially and were similar to those found in other coastal regions of high urban use. Concentrations were independent of grain size and OM suggesting that physical processes other than those that govern natural sediment components determine the fate of microplastics within sediments. Under laboratory conditions, concentrations of ammonium were significantly greater in the overlying water of treatments with microplastics, clams, and OM compared with treatments without microplastics. These preliminary studies suggest that high concentrations of microplastics have the potential to alter key sedimentary processes such as ammonium flux. This could have serious implications, for example, contributing to eutrophication events in regions of the coast that are highly urbanized. PMID:25916196

  14. Shellfish depuration by gamma irradiation: Final report for the period October 1, 1985-September 30, 1986

    SciTech Connect

    Beghian, L.; Melnick, J.

    1986-11-01

    Irradiation of live bivalve molluscs is a promising new technique to reduce the public health threats of viral and bacterial pathogens in the consumption of raw shellfish. In studies conducted within the past year, live hardshelled clams and oysters were innoculated with Simian Rotavirus SA-11, Poliovirus I, and Hepatitis-A virus and treated with gamma ray ionizing radiation from University of Lowell/DOE 800,000 Curie /sup 60/Co source over a dose range of 0.5--10 kiloGray (50--1000 kilorad) to determine the effectiveness of the process in eliminating viral activity and thus easing the potential viral health threats associated with uncooked bivalves. Two viral strains, SA-11 and Poliovirus I, were employed as models to perfect laboratory technique and to estimate the most appropriate range of dose exposures necessary for optimal inactivation of the infectious pathogen, Hepatitis A. Post-irradiation survivorship of the oysters and quahogs was assessed over a range of exposures, and showed an exceptionally high degree of radioresistance for these molluscan species. 7 refs., 7 figs., 14 tabs.

  15. Trace metal residues in shellfish from Maryland waters, 1976-1980.

    PubMed

    Eisenberg, M; Topping, J J

    1984-10-01

    Levels of seven heavy metal residues, arsenic, cadmium, chromium, copper, lead, mercury and zinc were monitored in samples of the American oyster (Crassostrea virginica), the soft shell clam (Mya arenaria), the hard shell clam (Mercinaria mercinaria) and the blue crab (Callinectes sapidus). Samples were taken from the Maryland section of the Chesapeake Bay and its tributaries over a five year period (1976-80). This study was undertaken to provide an estimate of a baseline for values of trace heavy metals. Also, the oyster, being a non-mobile filter feeder, provides information regarding the level of metal residues in its environment (water and sediment), because heavy metal uptake is related to the surrounding metal concentrations. Additionally, this type of monitoring program is essential to ensure that shellfish sold for human consumption are within safe limits established for toxic substances by the United States Food and Drug Administration. Results of the study are consistent with data from previous years and no statistically significant year-to-year trends were observed over the period of the investigation. PMID:6501792

  16. Sea otter mortality in fish and shellfish traps: Estimating potential impacts and exploring possible solutions

    USGS Publications Warehouse

    Hatfield, B.B.; Ames, J.A.; Estes, J.A.; Tinker, M.T.; Johnson, A.B.; Staedler, M.M.; Harris, M.D.

    2011-01-01

    Sea otters Enhydra lutris can be bycaught and drowned in fishing pots and traps, which may pose a threat to the welfare of otter populations. We explored this potential problem and its solutions using a wide variety of analyses. We exposed live California (USA) sea otters to finfish traps, lobster traps, and mock Dungeness crab traps in captive trials and found that the animals attempted to enter the circular and rectangular fyke openings, with some becoming entrapped. Using both live and dead sea otters, we found that a 3 ?? 9 inch (7.6 ?? 22.9 cm) fyke opening (1 inch narrower than the 4 ?? 9 inch [10.2 ?? 22.9 cm] openings currently used in California's commercial Dungeness crab fishery) would exclude most free-living (i.e. weaned from their mothers) otters while permitting the undiminished capture of crabs. Observer programs do not currently exist in California for these fisheries, so we calculated the effort required by an observer program to document sea otter bycatch over a range of hypothetical levels and evaluated the impact of those mortality rates on population growth. These analyses demonstrate that significant mortality from bycatch might easily go undetected, even with seemingly high levels of observer effort. As sea otters reoccupy portions of their former habitat in California, co-occurrence with finfish and shellfish traps with relatively large fyke openings will increase. ?? Inter-Research 2011.

  17. Arsenic, cadmium, and manganese levels in shellfish from Map Ta Phut, an industrial area in Thailand, and the potential toxic effects on human cells.

    PubMed

    Rangkadilok, Nuchanart; Siripriwon, Pantaree; Nookabkaew, Sumontha; Suriyo, Tawit; Satayavivad, Jutamaad

    2015-01-01

    Map Ta Phut Industrial Estate is a major industrial area in Thailand for both petrochemical and heavy industries. The release of hazardous wastes and other pollutants from these industries increases the potential for contamination in foods in the surrounding area, especially farmed shellfish. This study determined the arsenic (As), cadmium (Cd), and manganese (Mn) concentrations in the edible flesh of farmed shellfish, including Perna viridis, Meretrix meretrix, and Scapharca inaequivalvis, around the Map Ta Phut area using inductively coupled plasma mass spectrometry. The results showed that shellfish samples contained high levels of total As [1.84-6.42 mg kg(-1) wet weight (ww)]. High Mn concentrations were found in P. viridis and M. meretrix, whereas S. inaequivalis contained the highest Cd. Arsenobetaine (AsB) was found to be the major As species in shellfish (>45% of total As). The in vitro cytotoxicity of these elements was evaluated using human cancer cells (T47D, A549, and Jurkat cells). An observed decrease in cell viability in T47D and Jurkat cells was mainly caused by exposure to inorganic As (iAs) or Mn but not to AsB or Cd. The combined elements (AsB+Mn+Cd) at concentrations predicted to result from the estimated daily intake of shellfish flesh by the local people showed significant cytotoxicity in T47D and Jurkat cells. PMID:24986306

  18. Dinophysis caudata generated lipophilic shellfish toxins in bivalves from the Nanji Islands, East China Sea

    NASA Astrophysics Data System (ADS)

    Jiang, Tao; Xu, Yixiao; Li, Yang; Qi, Yuzao; Jiang, Tianjiu; Wu, Feng; Zhang, Fan

    2014-01-01

    A 12-month program of monitoring potentially toxic microalgae (that produce lipophilic shellfish toxins; LSTs) and their toxins in bivalves was conducted from April 2006 to March 2007 in the Nanji Islands, East China Sea. Two Dinophysis species, D. caudata and D. acuminata, were identified, and D. caudata was found to be the dominant species. D. caudata was detected in water samples between April and June 2006, and between February and March 2007. It reached its highest abundances in May, with a mean abundance of 1.38102 cells/L in surface water and 1.25102 cells/L in bottom water (<10 m deep). The temporal distribution of D. caudata was associated with the occurrence of LSTs in bivalve samples, which mostly occurred at the same time as D. caudata blooms, between April and July 2006. All of the cultured bivalves sampled between April and June were contaminated with LSTs, with an average toxicity of 85 ?g okadaic acid (OA) eq./100 g meat, which was four times higher than the Chinese regulatory limit (20 ?g OA eq./100 g meat). Ten out of fifteen wild samples (66.7%) collected during the same period were positive for LSTs, and contained an average LST toxicity of 45 ?g OA eq./100 g meat (more than twice the regulatory value). Cultured Patinopecten yessoensis collected on 15 May 2006 had the highest toxicity, 320 ?g OA eq./100 g meat, and relatively high toxicities (80 to 160 ?g OA eq./100 g meat) were found in bivalves until the end of July.

  19. Environmental effects of modified clay flocculation on Alexandrium tamarense and paralytic shellfish poisoning toxins (PSTs).

    PubMed

    Lu, Guangyuan; Song, Xiuxian; Yu, Zhiming; Cao, Xihua; Yuan, Yongquan

    2015-05-01

    Among various mitigation strategies for harmful algal blooms (HABs), the flocculation of algal cells by using modified clay (MC) has been widely applied in the field, particularly in Japan, Korea and China. However, to examine the long-term effects and the environmental safety of this method, we investigated alterations in macronutrients and paralytic shellfish poisoning toxins (PSTs) induced by the application of MC treatment to a toxic bloom, Alexandrium tamarense. The control, algal cells grew in nature condition (A1), was compared to the only MC flocculation (A2) and the MC-sediment co-matrix systems of A. tamarense (A3). The low-dosage of 0.25 g L(-1) MC could efficiently remove >90% of the A. tamarense cells within 3.5h. The mechanisms underlying the effects elicited by MC flocculation on nutrient cycling, PSTs and Chl-a degradation were also discussed. This study demonstrated that MC treatment was able to significantly remove the macronutrients (43-60% TP removal and 17-30% TN removal) and scavenge most of the PSTs from seawater, thereby speeding up the nutrient settling and the transformation and degradation of PSTs (83% decreasing in A2). Simultaneously, the study firstly demonstrated the potential detoxification of PSTs by using MC treatment, from the high toxicity of gonyautoxin 1 and 4 (GTX1 and GTX4) to the lower toxicity decarbamoyl gonyautoxins (dcGTX3) and gonyautoxin 2 (GTX2), particularly within the water-sediment environment during the two month incubation. PMID:25721022

  20. Phylogeography of cylindrospermopsin and paralytic shellfish toxin-producing nostocales cyanobacteria from mediterranean europe (Spain).

    PubMed

    Cirs, Samuel; Wrmer, Lars; Ballot, Andreas; Agha, Ramsy; Wiedner, Claudia; Velzquez, David; Casero, Mara Cristina; Quesada, Antonio

    2014-02-01

    Planktonic Nostocales cyanobacteria represent a challenge for microbiological research because of the wide range of cyanotoxins that they synthesize and their invasive behavior, which is presumably enhanced by global warming. To gain insight into the phylogeography of potentially toxic Nostocales from Mediterranean Europe, 31 strains of Anabaena (Anabaena crassa, A. lemmermannii, A. mendotae, and A. planctonica), Aphanizomenon (Aphanizomenon gracile, A. ovalisporum), and Cylindrospermopsis raciborskii were isolated from 14 freshwater bodies in Spain and polyphasically analyzed for their phylogeography, cyanotoxin production, and the presence of cyanotoxin biosynthesis genes. The potent cytotoxin cylindrospermopsin (CYN) was produced by all 6 Aphanizomenon ovalisporum strains at high levels (5.7 to 9.1 ?g CYN mg(-1) [dry weight]) with low variation between strains (1.5 to 3.9-fold) and a marked extracellular release (19 to 41% dissolved CYN) during exponential growth. Paralytic shellfish poisoning (PSP) neurotoxins (saxitoxin, neosaxitoxin, and decarbamoylsaxitoxin) were detected in 2 Aphanizomenon gracile strains, both containing the sxtA gene. This gene was also amplified in non-PSP toxin-producing Aphanizomenon gracile and Aphanizomenon ovalisporum. Phylogenetic analyses supported the species identification and confirmed the high similarity of Spanish Anabaena and Aphanizomenon strains with other European strains. In contrast, Cylindrospermopsis raciborskii from Spain grouped together with American strains and was clearly separate from the rest of the European strains, raising questions about the current assumptions of the phylogeography and spreading routes of C. raciborskii. The present study confirms that the nostocalean genus Aphanizomenon is a major source of CYN and PSP toxins in Europe and demonstrates the presence of the sxtA gene in CYN-producing Aphanizomenon ovalisporum. PMID:24334673

  1. Matrix effect on paralytic shellfish toxins quantification and toxicity estimation in mussels exposed to Gymnodinium catenatum.

    PubMed

    Botelho, M J; Vale, C; Mota, A M; Rodrigues, S M; Costa, P R; Simes Gonalves, M L S

    2010-12-01

    Paralytic shellfish toxins were quantified in whole tissues of the mussel Mytilus galloprovincialis exposed to blooms of the dinoflagellate Gymnodinium catenatum in Portuguese coastal waters. A validated liquid chromatography method with fluorescence detection, involving pre-chromatographic oxidation was used to quantify carbamoyl, N-sulfocarbamoyl and decarbamoyl toxins. In order to test for any matrix effect in the quantification of those toxins, concentrations obtained from solvent and matrix matched calibration curves were compared. A suppression of the fluorescence signal was observed in mussel extract or fraction in comparison to solvent for the compounds dcGTX2 + 3, GTX2 + 3 and GTX1 + 4, while an enhancement was found for C1 + 2, dcSTX, STX, B1, dcNEO and NEO. These results showed that a matrix effect varies among compounds. The difference of concentrations between solvent and matrix matched calibration curves for C1 + 2 (median = 421 ng g?) exceeded largely the values for the other quantified compounds (0.09-58 ng g?). Those differences were converted into toxicity differences, using Oshima toxicity equivalence factors. The compounds C1 + 2 and dcNEO were the major contributors to the differences of total toxicity in the mussel samples. The differences of total toxicity were calculated in ten mussel samples collected during a 10-week blooming period in Portuguese coastal lagoon. Values varied between 53 and 218 g STX equivalents kg?. The positive differences mean that the estimated toxicity using solvent calibration curves exceed the values taking into account the matrix. For the toxicity interval 200-800 g STX equivalents kg? an increase was found between 44 and 28%. PMID:21108093

  2. Ancient Clam Gardens Increased Shellfish Production: Adaptive Strategies from the Past Can Inform Food Security Today

    PubMed Central

    Groesbeck, Amy S.; Rowell, Kirsten; Lepofsky, Dana; Salomon, Anne K.

    2014-01-01

    Maintaining food production while sustaining productive ecosystems is among the central challenges of our time, yet, it has been for millennia. Ancient clam gardens, intertidal rock-walled terraces constructed by humans during the late Holocene, are thought to have improved the growing conditions for clams. We tested this hypothesis by comparing the beach slope, intertidal height, and biomass and density of bivalves at replicate clam garden and non-walled clam beaches in British Columbia, Canada. We also quantified the variation in growth and survival rates of littleneck clams (Leukoma staminea) we experimentally transplanted across these two beach types. We found that clam gardens had significantly shallower slopes than non-walled beaches and greater densities of L. staminea and Saxidomus giganteus, particularly at smaller size classes. Overall, clam gardens contained 4 times as many butter clams and over twice as many littleneck clams relative to non-walled beaches. As predicted, this relationship varied as a function of intertidal height, whereby clam density and biomass tended to be greater in clam gardens compared to non-walled beaches at relatively higher intertidal heights. Transplanted juvenile L. staminea grew 1.7 times faster and smaller size classes were more likely to survive in clam gardens than non-walled beaches, specifically at the top and bottom of beaches. Consequently, we provide strong evidence that ancient clam gardens likely increased clam productivity by altering the slope of soft-sediment beaches, expanding optimal intertidal clam habitat, thereby enhancing growing conditions for clams. These results reveal how ancient shellfish aquaculture practices may have supported food security strategies in the past and provide insight into tools for the conservation, management, and governance of intertidal seascapes today. PMID:24618748

  3. Paralytic Shellfish Poisoning Toxin-Producing Cyanobacterium Aphanizomenon gracile in Northeast Germany▿ †

    PubMed Central

    Ballot, Andreas; Fastner, Jutta; Wiedner, Claudia

    2010-01-01

    Neurotoxic paralytic shellfish poisoning (PSP) toxins, anatoxin-a (ATX), and hepatotoxic cylindrospermopsin (CYN) have been detected in several lakes in northeast Germany during the last 2 decades. They are produced worldwide by members of the nostocalean genera Anabaena, Cylindrospermopsis, and Aphanizomenon. Although no additional sources of PSP toxins and ATX have been identified in German water bodies to date, the observed CYN concentrations cannot be produced solely by Aphanizomenon flos-aquae, the only known CYN producer in Germany. Therefore, we attempted to identify PSP toxin, ATX, and CYN producers by isolating and characterizing 92 Anabaena, Aphanizomenon, and Anabaenopsis strains from five lakes in northeast Germany. In a polyphasic approach, all strains were morphologically and phylogenetically classified and then tested for PSP toxins, ATX, and CYN by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and enzyme-linked immunosorbent assay (ELISA) and screened for the presence of PSP toxin- and CYN-encoding gene fragments. As demonstrated by ELISA and LC-MS, 14 Aphanizomenon gracile strains from Lakes Melang and Scharmützel produced four PSP toxin variants (gonyautoxin 5 [GTX5], decarbamoylsaxitoxin [dcSTX], saxitoxin [STX], and neosaxitoxin [NEO]). GTX5 was the most prevalent PSP toxin variant among the seven strains from Lake Scharmützel, and NEO was the most prevalent among the seven strains from Lake Melang. The sxtA gene, which is part of the saxitoxin gene cluster, was found in the 14 PSP toxin-producing A. gracile strains and in 11 non-PSP toxin-producing Aphanizomenon issatschenkoi, A. flos-aquae, Anabaena planktonica, and Anabaenopsis elenkinii strains. ATX and CYN were not detected in any of the isolated strains. This study is the first confirming the role of A. gracile as a PSP toxin producer in German water bodies. PMID:20048055

  4. Paralytic shellfish poisoning toxin-producing cyanobacterium Aphanizomenon gracile in northeast Germany.

    PubMed

    Ballot, Andreas; Fastner, Jutta; Wiedner, Claudia

    2010-02-01

    Neurotoxic paralytic shellfish poisoning (PSP) toxins, anatoxin-a (ATX), and hepatotoxic cylindrospermopsin (CYN) have been detected in several lakes in northeast Germany during the last 2 decades. They are produced worldwide by members of the nostocalean genera Anabaena, Cylindrospermopsis, and Aphanizomenon. Although no additional sources of PSP toxins and ATX have been identified in German water bodies to date, the observed CYN concentrations cannot be produced solely by Aphanizomenon flos-aquae, the only known CYN producer in Germany. Therefore, we attempted to identify PSP toxin, ATX, and CYN producers by isolating and characterizing 92 Anabaena, Aphanizomenon, and Anabaenopsis strains from five lakes in northeast Germany. In a polyphasic approach, all strains were morphologically and phylogenetically classified and then tested for PSP toxins, ATX, and CYN by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and enzyme-linked immunosorbent assay (ELISA) and screened for the presence of PSP toxin- and CYN-encoding gene fragments. As demonstrated by ELISA and LC-MS, 14 Aphanizomenon gracile strains from Lakes Melang and Scharmtzel produced four PSP toxin variants (gonyautoxin 5 [GTX5], decarbamoylsaxitoxin [dcSTX], saxitoxin [STX], and neosaxitoxin [NEO]). GTX5 was the most prevalent PSP toxin variant among the seven strains from Lake Scharmtzel, and NEO was the most prevalent among the seven strains from Lake Melang. The sxtA gene, which is part of the saxitoxin gene cluster, was found in the 14 PSP toxin-producing A. gracile strains and in 11 non-PSP toxin-producing Aphanizomenon issatschenkoi, A. flos-aquae, Anabaena planktonica, and Anabaenopsis elenkinii strains. ATX and CYN were not detected in any of the isolated strains. This study is the first confirming the role of A. gracile as a PSP toxin producer in German water bodies. PMID:20048055

  5. Prevalence of human noroviruses in frozen marketed shellfish, red fruits and fresh vegetables.

    TOXLINE Toxicology Bibliographic Information

    Loutreul J; Cazeaux C; Levert D; Nicolas A; Vautier S; Le Sauvage AL; Perelle S; Morin T

    2014-09-01

    Noroviruses (NoVs), currently recognised as the most common human food-borne pathogens, are ubiquitous in the environment and can be transmitted to humans through multiple foodstuffs. In this study, we evaluated the prevalence of human NoV genogroups I (GI) and II (GII) in 493 food samples including soft red fruits (n = 200), salad vegetables (n = 210) and bivalve mollusc shellfish (n = 83), using the Bovine Enterovirus type 1 as process extraction control for the first time. Viral extractions were performed by elution concentration and genome detection by TaqMan Real-Time RT-PCR (RT-qPCR). Experimental contamination using hepatitis A virus (HAV) was used to determine the limit of detection (LOD) of the extraction methods. Positive detections were obtained from 2 g of digestive tissues of oysters or mussels kept for 16 h in seawater containing 2.0-2.7 log10 plaque-forming units (PFU)/L of HAV. For lettuces and raspberries, the LOD was, respectively, estimated at 2.2 and 2.9 log10 PFU per 25 g. Of the molluscs tested, 8.4 and 14.4% were, respectively, positive for the presence of GI NoV and GII NoV RNA. Prevalence in GI NoVs varied from 11.9% for the salad vegetables samples to 15.5% for the red soft fruits. Only 0.5% of the salad and red soft fruits samples were positive for GII NoVs. These results highlight the high occurrence of human NoVs in foodstuffs that can be eaten raw or after a moderate technological processing or treatment. The determination of the risk of infection associated with an RT-qPCR positive sample remains an important challenge for the future.

  6. Phylogeography of Cylindrospermopsin and Paralytic Shellfish Toxin-Producing Nostocales Cyanobacteria from Mediterranean Europe (Spain)

    PubMed Central

    Cirés, Samuel; Wörmer, Lars; Ballot, Andreas; Agha, Ramsy; Wiedner, Claudia; Velázquez, David; Casero, María Cristina

    2014-01-01

    Planktonic Nostocales cyanobacteria represent a challenge for microbiological research because of the wide range of cyanotoxins that they synthesize and their invasive behavior, which is presumably enhanced by global warming. To gain insight into the phylogeography of potentially toxic Nostocales from Mediterranean Europe, 31 strains of Anabaena (Anabaena crassa, A. lemmermannii, A. mendotae, and A. planctonica), Aphanizomenon (Aphanizomenon gracile, A. ovalisporum), and Cylindrospermopsis raciborskii were isolated from 14 freshwater bodies in Spain and polyphasically analyzed for their phylogeography, cyanotoxin production, and the presence of cyanotoxin biosynthesis genes. The potent cytotoxin cylindrospermopsin (CYN) was produced by all 6 Aphanizomenon ovalisporum strains at high levels (5.7 to 9.1 μg CYN mg−1 [dry weight]) with low variation between strains (1.5 to 3.9-fold) and a marked extracellular release (19 to 41% dissolved CYN) during exponential growth. Paralytic shellfish poisoning (PSP) neurotoxins (saxitoxin, neosaxitoxin, and decarbamoylsaxitoxin) were detected in 2 Aphanizomenon gracile strains, both containing the sxtA gene. This gene was also amplified in non-PSP toxin-producing Aphanizomenon gracile and Aphanizomenon ovalisporum. Phylogenetic analyses supported the species identification and confirmed the high similarity of Spanish Anabaena and Aphanizomenon strains with other European strains. In contrast, Cylindrospermopsis raciborskii from Spain grouped together with American strains and was clearly separate from the rest of the European strains, raising questions about the current assumptions of the phylogeography and spreading routes of C. raciborskii. The present study confirms that the nostocalean genus Aphanizomenon is a major source of CYN and PSP toxins in Europe and demonstrates the presence of the sxtA gene in CYN-producing Aphanizomenon ovalisporum. PMID:24334673

  7. Mercury in UK imported fish and shellfish and UK-farmed fish and their products.

    PubMed

    Knowles, T G; Farrington, D; Kestin, S C

    2003-09-01

    Total mercury concentrations were measured in fish and shellfish and their products imported into the UK and also in UK-produced farmed salmon and trout. Three hundred and thirty-six samples were collected using a two-stage sampling plan. The sample plan was weighted to reflect consumption, but with some bias towards fish that might accumulate higher levels of mercury, such as large predatory fish at the top of the food chain. The highest levels of total mercury were found in billfish (swordfish and marlin) and shark. Mercury concentrations in the five samples of fresh/frozen shark ranged from 1.006 to 2.200 mg kg(-1), all above the European Commission limit for the species, and concentrations in 20 samples of fresh/frozen billfish ranged from 0.153 to 2.706 mg kg(-1) with 13 samples above the 1.0 mg kg(-1) limit for the species. One sample of Antarctic ice fish was collected and had a mercury concentration of 0.664 mg kg(-1). The limit for this species was 0.5 mg kg(-1). One sample of fresh/frozen tuna out of the 20 collected had a mercury concentration above the limit of 1.0 mg kg(-1) (1.5 mg kg(-1)), but all other fresh tuna samples were well within the regulatory limit (average 0.4 mg kg(-1)). Mercury concentrations in canned tuna were lower with concentrations on average half that measured in fresh/frozen tuna. Mercury concentrations in UK-farmed salmon and trout were relatively low. The maximum concentration found in 46 samples of fresh/frozen or smoked trout and salmon was 0.103 mg kg(-1). PMID:13129776

  8. Occurrence of legacy and emerging halogenated organic contaminants in marine shellfish along French coasts.

    PubMed

    Munschy, C; Olivier, N; Veyrand, B; Marchand, P

    2015-01-01

    Current contamination levels of selected legacy, currently-used and emerging halogenated contaminants were monitored in marine shellfish along French coastlines. The studied contaminants included polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDDs), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), decabromodiphenylethane (DBDPE), hexabromobenzene (HBB), 2,2′,4,4′,5,5′-hexabromobiphenyl (BB-153) and perfluorinated compounds (PFCs).BDE-47, BDE-209, BTBPE, HBB and α-HBCDD were detected in 100% of the analyzed samples, whereas BB-153, DBDPE and PFOS were detected at frequencies of 97%, 90% and 55%, respectively. Concentrations were in the pg g−1 ww range and varied as follows: PFOS > BDE-47 ∼ α-HBCDD > BDE-209 > BTBPE ∼ DBDPE > HBB ∼ BB-153. Overall, non-PBDE Brominated Flame Retardants (BFRs) revealed concentrations between 3 and 59 times lower than those of PBDEs.PBDE pattern was dominated by BDE-47, followed by BDE-99 > BDE-100 > BDE-49 > BDE-209 > BDE-154; these 6 congeners represented 94% of the summed ten PBDEs. PFC pattern determination revealed PFOS as the predominant PFC in samples from the English Channel and Atlantic, whereas perfluorocarboxylic acids (PFCAs) prevailed in Mediterranean samples. Temporal trend investigations on archived samples from the Mediterranean coast collected between 1981 and 2012 showed a prevalence of PFOS until 1998; PFCAs subsequently increased and became more abundant than PFOS. High levels of PFCAs were observed until 2008, followed by a decrease and stabilization in 2010–2012. Amongst PFCAs, perfluorotridecanoic acid (PFTrDA) and perfluoroundecanoic acid (PFUnA) were predominant and exhibited similar time trends, suggesting similar sources at the investigated site, home to major industrial activity. PMID:25463258

  9. Freeze-drying for the stabilisation of shellfish toxins in mussel tissue (Mytilus edulis) reference materials.

    PubMed

    McCarron, Pearse; Emteborg, Hkan; Hess, Philipp

    2007-04-01

    Two samples of mussels (Mytilus edulis) were collected from the southwest of Ireland. One sample contained domoic acid, the other sample contained okadaic acid, dinophysistoxin-2 and azaspiracid-1, -2 and -3. Wet and freeze-dried reference materials were prepared from each of the two samples to test for differences in homogeneity, stability and extractability of the analytes in either condition. Wet materials were homogenised, aliquoted and hermetically sealed under argon and subsequently frozen at -80 degrees C. Dry materials were similarly homogenised but frozen in flat cakes prior to freeze-drying. After grinding, sieving and further homogenisation, the resulting powder was aliquoted and hermetically sealed. Domoic acid materials were characterised using HPLC-UV, while LC-MS was used for the determination of lipophilic toxins. The extractabilities of all phycotoxins studied were comparable for wet and freeze-dried materials once a sonication step had been carried out for reconstitution of the freeze-dried materials prior to extraction. Homogeneity was assessed through replicate analysis of the phycotoxins (n = 10), and was found to be similar for wet and freeze-dried materials, for both hydrophilic and lipophilic toxins. Water contents were determined for both wet and freeze-dried materials, and particle size was determined for the freeze-dried materials. Stability was evaluated isochronously over eight months at four temperatures (-20, +4, +20 and +40 degrees C). The freeze-dried material containing domoic acid was stable over the whole duration at all temperatures, while in the wet material domoic acid degraded to some extent at all temperatures except -20 degrees C. In freeze-dried and wet materials containing lipophilic toxins, okadaic acid, dinophysistoxin-2, azaspiracid-1 and azaspiracid-2 were stable over the whole duration at all conditions, while concentrations of azaspiracid-3 changed significantly in both materials at some storage temperatures. Figure Aliquots of freeze-dried and wet mussel tissue reference materials containing the various shellfish toxins examined in the study. PMID:17256111

  10. Categorizing the severity of paralytic shellfish poisoning outbreaks in the Gulf of Maine for forecasting and management.

    PubMed

    Kleindinst, Judith L; Anderson, Donald M; McGillicuddy, Dennis J; Stumpf, Richard P; Fisher, Kathleen M; Couture, Darcie A; Hickey, J Michael; Nash, Christopher

    2014-05-01

    Development of forecasting systems for harmful algal blooms (HABs) has been a long-standing research and management goal. Significant progress has been made in the Gulf of Maine, where seasonal bloom forecasts are now being issued annually using Alexandrium fundyense cyst abundance maps and a population dynamics model developed for that organism. Thus far, these forecasts have used terms such as "significant", "moderately large" or "moderate" to convey the extent of forecasted paralytic shellfish poisoning (PSP) outbreaks. In this study, historical shellfish harvesting closure data along the coast of the Gulf of Maine were used to derive a series of bloom severity levels that are analogous to those used to define major storms like hurricanes or tornados. Thirty-four years of PSP-related shellfish closure data for Maine, Massachusetts and New Hampshire were collected and mapped to depict the extent of coastline closure in each year. Due to fractal considerations, different methods were explored for measuring length of coastline closed. Ultimately, a simple procedure was developed using arbitrary straight-line segments to represent specific sections of the coastline. This method was consistently applied to each year's PSP toxicity closure map to calculate the total length of coastline closed. Maps were then clustered together statistically to yield distinct groups of years with similar characteristics. A series of categories or levels was defined ("Level 1: Limited", "Level 2: Moderate", and "Level 3: Extensive") each with an associated range of expected coastline closed, which can now be used instead of vague descriptors in future forecasts. This will provide scientifically consistent and simply defined information to the public as well as resource managers who make decisions on the basis of the forecasts. PMID:25076815

  11. Categorizing the severity of paralytic shellfish poisoning outbreaks in the Gulf of Maine for forecasting and management

    PubMed Central

    Kleindinst, Judith L.; Anderson, Donald M.; McGillicuddy, Dennis J.; Stumpf, Richard P.; Fisher, Kathleen M.; Couture, Darcie A.; Hickey, J. Michael; Nash, Christopher

    2014-01-01

    Development of forecasting systems for harmful algal blooms (HABs) has been a long-standing research and management goal. Significant progress has been made in the Gulf of Maine, where seasonal bloom forecasts are now being issued annually using Alexandrium fundyense cyst abundance maps and a population dynamics model developed for that organism. Thus far, these forecasts have used terms such as significant, moderately large or moderate to convey the extent of forecasted paralytic shellfish poisoning (PSP) outbreaks. In this study, historical shellfish harvesting closure data along the coast of the Gulf of Maine were used to derive a series of bloom severity levels that are analogous to those used to define major storms like hurricanes or tornados. Thirty-four years of PSP-related shellfish closure data for Maine, Massachusetts and New Hampshire were collected and mapped to depict the extent of coastline closure in each year. Due to fractal considerations, different methods were explored for measuring length of coastline closed. Ultimately, a simple procedure was developed using arbitrary straight-line segments to represent specific sections of the coastline. This method was consistently applied to each years PSP toxicity closure map to calculate the total length of coastline closed. Maps were then clustered together statistically to yield distinct groups of years with similar characteristics. A series of categories or levels was defined (Level 1: Limited, Level 2: Moderate, and Level 3: Extensive) each with an associated range of expected coastline closed, which can now be used instead of vague descriptors in future forecasts. This will provide scientifically consistent and simply defined information to the public as well as resource managers who make decisions on the basis of the forecasts. PMID:25076815

  12. Snapshot of Vibrio parahaemolyticus densities in open and closed shellfish beds in Coastal South Carolina and Mississippi.

    PubMed

    Moore, J Gooch; Ruple, A; Ballenger-Bass, K; Bell, S; Pennington, P L; Scott, G I

    2014-11-01

    Vibrio parahaemolyticus is a Gram negative, halophilic bacterium that is ubiquitous in warm, tropical waters throughout the world. It is a major cause of seafood-associated gastroenteritis and is generally associated with consumption of raw or undercooked seafood, especially oysters. This study presents a snapshot of total V. parahaemolyticus densities in surface waters and shellstock American oysters (Crassostrea virginica) from open and closed shellfish harvesting areas, as well as "more rural areas" on two different US coasts, the Atlantic and the Gulf. Sampling was conducted from 2001 to 2003 at five sites near Charleston/Georgetown, SC and at four locations in the Gulfport/Pascagoula, MS area. V. parahaemolyticus numbers were determined by a direct plating method using an alkaline-phosphatase-labeled DNA probe targeting the species-specific thermolabile hemolysin gene (tlh) that was used for identification of bacterial isolates. The greatest difference between the two coasts was salinity; mean salinity in SC surface waters was 32.9ppt, whereas the mean salinity in MS waters was 19.2ppt, indicating more freshwater input into MS shellfish harvesting areas during the study period. The mean V. parahaemolyticus numbers in oysters were almost identical between the two states (567.4 vs. 560.1CFU/g). Bacterial numbers in the majority of surface water samples from both states were at or below the limit of detection (LOD?=?<10CFU/mL). The bacterial concentrations determined during this study predict a low public health risk from consumption of oysters in shellfish growing areas on either the Gulf or the Atlantic US coast. PMID:25106119

  13. Effects of storage on microbial loads of two commercially important shellfish species, Crassostrea virginica and Mercenaria campechiensis.

    PubMed

    Hood, M A; Ness, G E; Rodrick, G E; Blake, N J

    1983-04-01

    The effects of storage on the microbial load in two commercially important species of shellfish were examined. Oysters (Crassostrea virginica) were stored as shellstock, shucked meats, and fully processed meats at four temperatures for up to 21 days, and clams (Mercenaria campechiensis) were stored only as shellstock. The concentrations of most microbiological groups of organisms increased with the duration and temperature of storage in both shellfish species, although the increases were significantly lower in claims. Concentrations of Vibrio cholerae rose by approximately 1 log in oysters stored as shellstock after 7 days at 2 degrees C, and Lac+ vibrios increased 2 logs at 8 degrees C. Total counts of bacteria, fungi, coliforms, fecal streptococci, Aeromonas hydrophila, and clostridia were significantly higher in shucked oysters than in those stored as shellstock. Fecal coliforms were statistically the same, but V. cholerae, Vibrio parahaemolyticus, and the Lac+ vibrios were higher in oysters stored as shellstock. The concentrations of all microbial groups were higher in fully processed oysters than in shucked meats, with the exception of the vibrios, which showed no significant difference among the treatments. The results showed that although traditional methods of storing shellfish resulted in an overall increase in the microbial load, vibrio levels increased only in oysters stored as shellstock. Although fecal coliform and total bacterial counts did not correlate with those for vibrios in fresh oysters, strong correlations were observed in oysters stored for 7 days, suggesting that these indicators may be useful in monitoring oyster quality when meats are stored for a limited time as shellstock. PMID:6859844

  14. Categorizing the severity of paralytic shellfish poisoning outbreaks in the Gulf of Maine for forecasting and management

    NASA Astrophysics Data System (ADS)

    Kleindinst, Judith L.; Anderson, Donald M.; McGillicuddy, Dennis J.; Stumpf, Richard P.; Fisher, Kathleen M.; Couture, Darcie A.; Michael Hickey, J.; Nash, Christopher

    2014-05-01

    Development of forecasting systems for harmful algal blooms (HABs) has been a long-standing research and management goal. Significant progress has been made in the Gulf of Maine, where seasonal bloom forecasts are now being issued annually using Alexandrium fundyense cyst abundance maps and a population dynamics model developed for that organism. Thus far, these forecasts have used terms such as “significant”, “moderately large” or “moderate” to convey the extent of forecasted paralytic shellfish poisoning (PSP) outbreaks. In this study, historical shellfish harvesting closure data along the coast of the Gulf of Maine were used to derive a series of bloom severity levels that are analogous to those used to define major storms like hurricanes or tornados. Thirty-four years of PSP-related shellfish closure data for Maine, Massachusetts and New Hampshire were collected and mapped to depict the extent of coastline closure in each year. Due to fractal considerations, different methods were explored for measuring length of coastline closed. Ultimately, a simple procedure was developed using arbitrary straight-line segments to represent specific sections of the coastline. This method was consistently applied to each year’s PSP toxicity closure map to calculate the total length of coastline closed. Maps were then clustered together statistically to yield distinct groups of years with similar characteristics. A series of categories or levels was defined (“Level 1: Limited”, “Level 2: Moderate”, and “Level 3: Extensive”) each with an associated range of expected coastline closed, which can now be used instead of vague descriptors in future forecasts. This will provide scientifically consistent and simply defined information to the public as well as resource managers who make decisions on the basis of the forecasts.

  15. Removal of lipids and diarrhetic shellfish poisoning toxins from blue mussels (Mytilus edulis) during acid and alkaline isolation of proteins.

    PubMed

    Vareltzis, Patroklos; Undeland, Ingrid

    2008-05-28

    Diarrhetic shellfish poisoning (DSP) toxins pose a serious health risk for consumers of bivalves and other shellfish, as well as a huge economic burden for the bivalve-producing farmers. In this work, the aim was to utilize a solubilization-based protein-isolation method to produce a low-DSP toxin protein isolate from toxic blue mussels that are unsuitable for the whole shellfish market. A homogenate of whole mussel meat was solubilized at low pH (2.8) or high pH (11.1), followed by centrifugation and reprecipitation of the solubilized mussel proteins at the isoelectric pH. In a second centrifugation, precipitated proteins were collected. These processes resulted in 81 (acid solubilization) and 72% (alkaline solubilization) reduction in the initial DTX-1 toxin content of the mussel meat. No other DSP toxins were found in the protein isolates. Acid processing of mussel meat resulted in 50% reduction in the total lipid content, while alkaline treatment did not significantly affect the lipid content. The effect of citric acid and calcium chloride addition to the mussel meat-water homogenate on lipid and toxin content was also investigated. A poor correlation factor was surprisingly obtained between reductions in DTX-1 toxin and lipids in protein isolates from processed toxic mussels. Results from an analytical mass balance of the DTX-1 toxin during acid processing showed that 61% of this toxin ended up in the aqueous supernatant after the second centrifugation. The present study presents a promising alternative way of utilizing mussels for food production in periods when they are toxic. PMID:18454548

  16. Temporal and Spatial Variation in the Abundance of Total and Pathogenic Vibrio parahaemolyticus in Shellfish in China

    PubMed Central

    Han, Haihong; Li, Fengqin; Yan, Weixing; Guo, Yunchang; Li, Ning; Liu, Xiumei; Zhu, Jianghui; Xu, Jin; Chen, Yan; Li, Xiugui; Lv, Hong; Zhang, Yiqian; Cai, Te; Chen, Yuzhen

    2015-01-01

    We investigated the abundance of total and pathogenic Vibrio parahaemolyticus in shellfish sampled from four provinces in China during May 2013 and March 2014 using the most probable number-polymerase chain reaction (MPN-PCR) method. Total V. parahaemolyticus was detected in 67.7% of 496 samples. A total of 38.1% and 10.1% of samples exceeded 1,000 MPN g-1 and 10,000 MPN g-1, respectively. V. parahaemolyticus densities followed a seasonal and geographical trend, with Guangxi and Sichuan shellfish possessing total V. parahaemolyticus levels that were 100-fold higher than those of the Liaoning and Shandong regions. Moreover, the levels of V. parahaemolyticus were at least 10-fold higher in the summer and autumn than in the cooler seasons. Pathogenic V. parahaemolyticus levels were generally lower than total V. parahaemolyticus levels by several log units and tended to be high in samples contaminated with high total V. parahaemolyticus levels. The aqua farms had a lower prevalence but higher abundance of total V. parahaemolyticus compared to retail markets. The catering markets showed the lowest levels of total V. parahaemolyticus, but 20.0% of samples exceeded 1,000 MPN g-1. The levels of both total and pathogenic V. parahaemolyticus in oysters were higher than in clams. The log-transformed abundance of V. parahaemolyticus was significantly correlated with both water temperature and air temperature but not water salinity. These results provide baseline contamination data of V. parahaemolyticus in shellfish in China, which can be applied to local risk assessments to prioritize risk control to key sectors and evaluate the effectiveness of future control measures. PMID:26061712

  17. Use of genomic probes to detect hepatitis A virus and enterovirus RNAs in wild shellfish and relationship of viral contamination to bacterial contamination.

    PubMed Central

    Le Guyader, F; Apaire-Marchais, V; Brillet, J; Billaudel, S

    1993-01-01

    Genomic probes were used to investigate hepatitis A virus (HAV) and enterovirus RNAs in two types of shellfish from natural beds (Atlantic coast, France). After elution concentration, nucleic acid extracted by proteinase K and purified by phenol-chloroform and ethanol precipitation was assayed by dot blot hybridization. The probes used were a specific HAV probe corresponding to the 3' end (3D polymerase coding region) and an enterovirus probe corresponding to the 5' noncoding region. The method was first tested under experimental conditions by using virus-spiked shellfish before being applied under field conditions. Our results show that shellfish were highly contaminated: enterovirus and HAV RNAs were found in 63 and 67%, respectively, of samples examined with the riboprobes. On the same site, viral (HAV and enterovirus) RNAs were found in a larger fraction of cockles than mussels. Statistical tests of dependence showed no relationship between viral contamination and bacterial contamination (evaluated by fecal coliform counts). Images PMID:8285700

  18. Temporal genetic variability and host sources of Escherichia coli associated with fecal pollution from domesticated animals in the shellfish culture environment of Xiangshan Bay, East China Sea.

    PubMed

    Fu, Ling-Lin; Shuai, Jiang-Bing; Wang, Yanbo; Ma, Hong-Jia; Li, Jian-Rong

    2011-10-01

    This study was conducted to analyze the genetic variability of Escherichia coli from domesticated animal wastes for microbial source tracking (MST) application in fecal contaminated shellfish growing waters of Xiangshan Bay, East China Sea. (GTG)(5) primer was used to generate 1363 fingerprints from E. coli isolated from feces of known 9 domesticated animal sources around this shellfish culture area. Jackknife analysis of the complete (GTG)(5)-PCR DNA fingerprint library indicated that isolates were assigned to the correct source groups with an 84.28% average rate of correct classification. Based on one-year source tracking data, the dominant sources of E. coli were swine, chickens, ducks and cows in this water area. Moreover, annual and spatial changes of E. coli concentrations and host sources may affect the level and distribution of zoonotic pathogen species in waters. Our findings will further contribute to preventing fecal pollution in aquatic environments and quality control of shellfish. PMID:21645948

  19. Identification of 19-epi-okadaic acid, a new diarrhetic shellfish poisoning toxin, by liquid chromatography with mass spectrometry detection.

    PubMed

    Paz, Beatriz; Daranas, Antonio H; Cruz, Patricia G; Franco, Jos M; Norte, Manuel; Fernndez, Jos J

    2008-01-01

    Okadaic acid (1) (OA) and its congeners are mainly responsible for diarrhetic shellfish poisoning (DSP) syndrome. The presence of several OA derivatives have already been confirmed in Prorocentrum and Dinophysis spp. In this paper, we report on the detection and identification of a new DSP toxin, the OA isomer 19-epi-okadaic acid (2) (19-epi-OA), isolated from cultures of Prorocentrum belizeanum, by determining its retention time (RT) and fragmentation pattern using liquid chromatography coupled with mass spectrometry (LC-MS/MS). PMID:19005581

  20. Identification of 19-epi-okadaic Acid, a New Diarrhetic Shellfish Poisoning Toxin, by Liquid Chromatography with Mass Spectrometry Detection

    PubMed Central

    Paz, Beatriz; Daranas, Antonio H.; Cruz, Patricia G.; Franco, Jos M.; Norte, Manuel; Fernndez, Jos J.

    2008-01-01

    Okadaic acid (1) (OA) and its congeners are mainly responsible for diarrhetic shellfish poisoning (DSP) syndrome. The presence of several OA derivatives have already been confirmed in Prorocentrum and Dinophysis spp. In this paper, we report on the detection and identification of a new DSP toxin, the OA isomer 19-epi-okadaic acid (2) (19-epi-OA), isolated from cultures of Prorocentrum belizeanum, by determining its retention time (RT) and fragmentation pattern using liquid chromatography coupled with mass spectrometry (LCMS/MS). PMID:19005581

  1. Understanding interannual, decadal level variability in paralytic shellfish poisoning toxicity in the Gulf of Maine: the HAB Index

    PubMed Central

    Anderson, Donald M.; Couture, Darcie A.; Kleindinst, Judith L.; Keafer, Bruce A.; McGillicuddy, Dennis J.; Martin, Jennifer L.; Richlen, Mindy L.; Hickey, J. Michael; Solow, Andrew R.

    2013-01-01

    A major goal in harmful algal bloom (HAB) research has been to identify mechanisms underlying interannual variability in bloom magnitude and impact. Here the focus is on variability in Alexandrium fundyense blooms and paralytic shellfish poisoning (PSP) toxicity in Maine, USA, over 34 years (1978 2011). The Maine coastline was divided into two regions -eastern and western Maine, and within those two regions, three measures of PSP toxicity (the percent of stations showing detectable toxicity over the year, the cumulative amount of toxicity per station measured in all shellfish (mussel) samples during that year, and the duration of measurable toxicity) were examined for each year in the time series. These metrics were combined into a simple HAB Index that provides a single measure of annual toxin severity across each region. The three toxin metrics, as well as the HAB Index that integrates them, reveal significant variability in overall toxicity between individual years as well as long-term, decadal patterns or regimes. Based on different conceptual models of the system, we considered three trend formulations to characterize the long-term patterns in the Index a three-phase (mean-shift) model, a linear two-phase model, and a pulse-decline model. The first represents a regime shift or multiple equilibria formulation as might occur with alternating periods of sustained high and low cyst abundance or favorable and unfavorable growth conditions, the second depicts a scenario of more gradual transitions in cyst abundance or growth conditions of vegetative cells, and the third characterizes a sawtooth pattern in which upward shifts in toxicity are associated with major cyst recruitment events, followed by a gradual but continuous decline until the next pulse. The fitted models were compared using both residual sum of squares and Akaike's Information Criterion. There were some differences between model fits, but none consistently gave a better fit than the others. This statistical underpinning can guide efforts to identify physical and/or biological mechanisms underlying the patterns revealed by the HAB Index. Although A. fundyense cyst survey data (limited to 9 years) do not span the entire interval of the shellfish toxicity records, this analysis leads us to hypothesize that major changes in the abundance of A. fundyense cysts may be a primary factor contributing to the decadal trends in shellfish toxicity in this region. The HAB Index approach taken here is simple but represents a novel and potentially useful tool for resource managers in many areas of the world subject to toxic HABs. PMID:24948849

  2. Understanding interannual, decadal level variability in paralytic shellfish poisoning toxicity in the Gulf of Maine: The HAB Index

    NASA Astrophysics Data System (ADS)

    Anderson, Donald M.; Couture, Darcie A.; Kleindinst, Judith L.; Keafer, Bruce A.; McGillicuddy, Dennis J., Jr.; Martin, Jennifer L.; Richlen, Mindy L.; Hickey, J. Michael; Solow, Andrew R.

    2014-05-01

    A major goal in harmful algal bloom (HAB) research has been to identify mechanisms underlying interannual variability in bloom magnitude and impact. Here the focus is on variability in Alexandrium fundyense blooms and paralytic shellfish poisoning (PSP) toxicity in Maine, USA, over 34 years (1978-2011). The Maine coastline was divided into two regions - eastern and western Maine, and within those two regions, three measures of PSP toxicity (the percent of stations showing detectable toxicity over the year, the cumulative amount of toxicity per station measured in all shellfish (mussel) samples during that year, and the duration of measurable toxicity) were examined for each year in the time series. These metrics were combined into a simple HAB Index that provides a single measure of annual toxin severity across each region. The three toxin metrics, as well as the HAB Index that integrates them, reveal significant variability in overall toxicity between individual years as well as long-term, decadal patterns or regimes. Based on different conceptual models of the system, we considered three trend formulations to characterize the long-term patterns in the Index - a three-phase (mean-shift) model, a linear two-phase model, and a pulse-decline model. The first represents a regime shift or multiple equilibria formulation as might occur with alternating periods of sustained high and low cyst abundance or favorable and unfavorable growth conditions, the second depicts a scenario of more gradual transitions in cyst abundance or growth conditions of vegetative cells, and the third characterizes a sawtooth pattern in which upward shifts in toxicity are associated with major cyst recruitment events, followed by a gradual but continuous decline until the next pulse. The fitted models were compared using both residual sum of squares and Akaike's Information Criterion. There were some differences between model fits, but none consistently gave a better fit than the others. This statistical underpinning can guide efforts to identify physical and/or biological mechanisms underlying the patterns revealed by the HAB Index. Although A. fundyense cyst survey data (limited to 9 years) do not span the entire interval of the shellfish toxicity records, this analysis leads us to hypothesize that major changes in the abundance of A. fundyense cysts may be a primary factor contributing to the decadal trends in shellfish toxicity in this region. The HAB Index approach taken here is simple but represents a novel and potentially useful tool for resource managers in many areas of the world subject to toxic HABs.

  3. Paralytic shellfish poisoning toxins accumulation in purple clam Hiatula rostrata and toxic effect on milkfish Chanos chanos larval fish.

    PubMed

    Chen, C Y

    2001-11-01

    In an attempt to feed purple clams (Hiatula rostrata) with dinoglagellate Alexandrium minutum, the maximal accumulation toxicity of paralytic shellfish poisoning (PSP) toxins reached 40.6 MU/g on day 5 of feeding. Subsequently, the toxicity increased no further, although purple clams ingested more toxic algae. Furthermore, when milkfish (Chanos chanos) larvae were treated with toxic, nontoxic A. minutum or PSP toxin-containing extract in the water medium, it was found that the mortality of fish increased with the increasing concentrations of toxic algae. PSP toxin-containing extract did not show any toxic effect on milkfish larvae. PMID:11695819

  4. Suitability of postcolumn oxidation liquid chromatography method AOAC 2011.02 for monitoring paralytic shellfish toxins in Alaskan shellfish--initial pilot study versus mouse bioassay and in-house validation.

    PubMed

    Hignutt, Emanuel

    2014-01-01

    An in-house study was conducted to confirm the suitability of the postcolumn oxidation (PCOX) LC method, AOAC 2011.02, for regulatory monitoring of paralytic shellfish toxins (PSTs) in Alaskan shellfish. The following parameters were evaluated: calibration linearity, linear range, retention time stability, accuracy, repeatability, LOQ, and comparability with AOAC 959.08, the mouse bioassay (MBA) for PSTs. Mean recoveries for oyster homogenate spiked at 66 microg saxitoxin (STX) diHCI eq./100 g and 5 microg STX diHCI eq./100 g were 95 (n = 8) and 104%, respectively. Repeatability (n = 8) was 1.6 and 7% RSD, respectively. LOQ was estimated at 5 microg STX diHCl eq./100 g with S/N = 6 for STX. Comparability with the MBA was evaluated by duplicate analysis of regulatory samples using the original homogenate for both methods. Forty-one samples with MBA results varying between 40 and 500 microg STX diHCl eq./100 g were compared to corresponding PCOX values. The correlation coefficient (r2) = 0.96, with a slope of 2.1. The slope indicates an average 2X higher total toxicity result for PCOX versus MBA, a result that is consistent with prior literature showing low recoveries using the MBA. PMID:24830139

  5. Detection of cyanobacterial neurotoxin ?-N-methylamino-l-alanine within shellfish in the diet of an ALS patient in Florida.

    PubMed

    Banack, Sandra Anne; Metcalf, James S; Bradley, Walter G; Cox, Paul Alan

    2014-11-01

    Cyanobacteria produce the neurotoxic amino acid ?-N-methylamino-l-alanine (BMAA), which in contaminated marine waters has been found to accumulate in shellfish. Exposure to BMAA has been associated with an increased risk of neurodegenerative disease. Analysis of blinded samples found BMAA to be present in neuroproteins of individuals who died from ALS and ALS/PDC, but generally not in the brains of patients who died of causes unrelated to neurodegeneration or Huntington's disease, an autosomal dominant neurodegenerative disease. We here report support for a link between a patient with ALS and chronic exposure to the cyanobacterial neurotoxin BMAA via shellfish consumption. The patient had frequently eaten lobsters collected in Florida Bay for approximately 30 years. LC-MS/MS analysis of two lobsters which this ALS patient had placed in his freezer revealed BMAA at concentrations of 27 and 4 ?g/g, respectively, as well as the presence of 2,4-diaminobutyric acid (DAB), a BMAA isomer. Two additional lobsters recently collected from Florida Bay also contained the neurotoxins BMAA and DAB. These data suggest that invertebrates collected in water where cyanobacterial blooms are present, if consumed, may result in direct human exposure to these neurotoxic amino acids. The data support the assertion that prolonged exposure to BMAA may have played a role in the etiology of ALS in this patient. PMID:25123936

  6. Viral pollution in the environment and in shellfish: human adenovirus detection by PCR as an index of human viruses.

    PubMed

    Pina, S; Puig, M; Lucena, F; Jofre, J; Girones, R

    1998-09-01

    A study of the presence of human viruses (adenoviruses, enteroviruses, and hepatitis A viruses [HAVs]) in environmental and shellfish samples was carried out by applying DNA and cDNA amplification techniques by PCR. The detection of human adenoviruses by PCR was also examined as a potential molecular test to monitor viral pollution. The samples studied were urban and slaughterhouse sewage, river water, seawater, and shellfish. Enteroviruses were quantified by PFU in Buffalo green monkey kidney cells and fecal coliforms and phages of Bacteroides fragilis HSP40 were also evaluated in some of the samples. The amplification of viral DNA and cDNA has shown a high prevalence of human viruses that would not be detected by the use of classical techniques, such as the quantification of PFU in cell lines. The results of the analysis of slaughterhouse sewage samples together with the test of farm animal feces indicate that the adenoviruses and the HAVs detected in the environment are mostly of human origin. A significative correlation between the detection of human viruses by PCR and the values of bacteriophages of B. fragilis HSP40 in urban raw sewage was observed. Human adenoviruses were the viruses most frequently detected throughout the year, and all the samples that were positive for enteroviruses or HAVs were also positive for human adenoviruses. The results suggest that the detection of adenoviruses by PCR could be used as an index of the presence of human viruses in the environment where a molecular index is acceptable. PMID:9726885

  7. Human health risk assessment of heavy metals in tropical fish and shellfish collected from the river Buriganga, Bangladesh.

    PubMed

    Ahmed, Md Kawser; Baki, Mohammad Abdul; Islam, Md Saiful; Kundu, Goutam Kumar; Habibullah-Al-Mamun, Md; Sarkar, Santosh Kumar; Hossain, Md Muzammel

    2015-10-01

    Although fish, crustacean, and shellfish are significant sources of protein, they are currently affected by rapid industrialization, resulting in increased concentrations of heavy metals. Accumulation of heavy metals (V, Cr, Mn, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Sb, Ba, and Pb) and associated human health risk were investigated in three fish species, namely Ailia coila, Gagata youssoufi, and Mastacembelus pancalus; one crustacean (prawn), Macrobrachium rosenbergii; and one Gastropoda, Indoplanorbis exustus, collected from the Buriganga River, Bangladesh. Samples were collected from the professional fishermen. Cu was the most accumulated metal in M. rosenbergii. Ni, As, Ag, and Sb were in relatively lower concentrations, whereas relatively higher accumulation of Cr, Mn, Zn, and Se were recorded. Mn, Zn, and Pb were present in higher concentrations than the guidelines of various authorities. There were significant differences in metal accumulation among different fish, prawn, or shellfish species. Target hazard quotient (THQ) and target cancer risk (TR) were calculated to estimate the non-carcinogenic and carcinogenic health risks, respectively. The THQ for individual heavy metals were below 1 suggesting no potential health risk. But combined impact, estimated by hazard index (HI), suggested health risk for M. pancalus consumption. Although consumption of fish at current accumulation level is safe but continuous and excess consumption for a life time of more than 70 years has probability of target cancer risk. PMID:26044144

  8. Two quantitative real-time PCR assays for the detection of penaeid shrimp and blue crab, crustacean shellfish allergens.

    PubMed

    Eischeid, Anne C; Kim, Bang-hyun; Kasko, Sasha M

    2013-06-19

    Food allergen detection methods must be able to specifically detect minute quantities of an allergenic food in a complex food matrix. One technique that can be used is real-time PCR. For the work described here, real-time PCR assays were developed to detect penaeid shrimp and blue crab, crustacean shellfish allergens. The method was tested using shrimp meat and crab meat spiked into several types of foods, including canned soups, deli foods, meat, seafood, and prepared seafood products. Foods were spiked with either shrimp or crab at levels ranging from 0.1 to 10⁶ parts per million (ppm) and analyzed either raw or cooked by a variety of methods. Real-time PCR data were used to generate linear standard curves, and assays were evaluated with respect to linear range and reaction efficiency. Results indicate that both assays performed well in a variety of food types. High reaction efficiencies were achieved across a linear range of 6-8 orders of magnitude. Limits of detection were generally between 0.1 and 1 ppm. Cooking methods used to simulate thermal processing of foods had little effect on assay performance. This work demonstrates that real-time PCR can be a valuable tool in the detection of crustacean shellfish. PMID:23190158

  9. Methods for routine control of irradiated food: Determination of the irradiation status of shellfish by thermoluminescence analysis

    NASA Astrophysics Data System (ADS)

    Schreiber, G. A.; Hoffmann, A.; Helle, N.; Bgl, K. W.

    1994-06-01

    In some countries, clearance has been given for treating certain types of shellfish by ionizing radiation in order to increase the shelf-life and to reduce health hazards which might be caused by contaminating microorganisms. In the present study, thermoluminescence (TL) analysis was used to examine the irradiation status of shellfish products purchased from local suppliers. For analysis minerals were isolated from the guts of the animals. Although on none of the examined products an irradiation treatment prior to analysis could be shown, the results obtained on non-irradiated and irradiated products have revealed that irradiation within the commercially used dose range can clearly be detected. Already first glow TL intensities of minerald indicated irradiation treatments. Normalized TL signals of non-irradiated and irradiated samples were clearly separated. By calculation of differences of TL intensities and TL signals between non-irradiated and irradiated samples in dependency of integration temperature an optimized integration area for glow curves was determined. The result of this study agree well with results obtained by two large-scale intercomparisons between food control laboratories to detect irradiation treatment of spices and herbal products as well as of fruit and vegetables by TL analysis of contaminating minerals.

  10. Effects of past, present, and future ocean carbon dioxide concentrations on the growth and survival of larval shellfish

    PubMed Central

    Gobler, Christopher J.

    2010-01-01

    The combustion of fossil fuels has enriched levels of CO2 in the worlds oceans and decreased ocean pH. Although the continuation of these processes may alter the growth, survival, and diversity of marine organisms that synthesize CaCO3 shells, the effects of ocean acidification since the dawn of the industrial revolution are not clear. Here we present experiments that examined the effects of the oceans past, present, and future (21st and 22nd centuries) CO2 concentrations on the growth, survival, and condition of larvae of two species of commercially and ecologically valuable bivalve shellfish (Mercenaria mercenaria and Argopecten irradians). Larvae grown under near preindustrial CO2 concentrations (250 ppm) displayed significantly faster growth and metamorphosis as well as higher survival and lipid accumulation rates compared with individuals reared under modern day CO2 levels. Bivalves grown under near preindustrial CO2 levels displayed thicker, more robust shells than individuals grown at present CO2 concentrations, whereas bivalves exposed to CO2 levels expected later this century had shells that were malformed and eroded. These results suggest that the ocean acidification that has occurred during the past two centuries may be inhibiting the development and survival of larval shellfish and contributing to global declines of some bivalve populations. PMID:20855590

  11. Spatial distribution and multiannual trends of potentially toxic microalgae in shellfish farms along the Sardinian coast (NW Mediterranean Sea).

    PubMed

    Bazzoni, Anna Maria; Caddeo, Tiziana; Pulina, Silvia; Padedda, Bachisio M; Satta, Cecilia T; Sechi, Nicola; Lugli, Antonella

    2015-03-01

    In this study, the geographical distribution and multiannual trends of potentially toxic harmful algal species (HAS)were analysed at 18 mussel farms in Sardinia (Italy, North-Western Mediterranean Sea) using data derived from the Sardinian Regional Monitoring Programme (1988-2012). The results showed an increasing number of potentially toxic microalgae over the study period. Alexandrium catenella and Alexandrium minutum were the most harmful species detected. From 2002 to 2009, these species caused eight paralytic shellfish poisoning-positive events which temporarily stopped commercial trade of mussels. The statistical analysis indicated that some taxa exhibited temporal increasing trends in their abundance (e.g. Pseudo-nitzschia spp.), significant decrements (e.g. Dinophysis sp.), or both increasing and decreasing significant trends (e.g. A. minutum) at different sites, indicating the necessity of further in-depth studies, especially on certain taxa. Overall, the statistical elaboration of the long-term data provided useful signals for early detection of shellfish contamination by different potentially toxic HAS in defined sites. These signals can be used to develop best management practices. PMID:25655125

  12. Upwelling of Acidified Water: Not Just an Issue for Shellfish Hatcheries on the West Coast of the US

    NASA Astrophysics Data System (ADS)

    Poach, M.; Munroe, D.; Abrahamsen, I.

    2014-12-01

    Periodic upwelling events are known to occur off the coast of New Jersey during the summer. As with upwelling off the US West Coast, these events can transport acidified water to the surface and shoreward. To determine if upwelling events have the potential to impact shellfish hatcheries in New Jersey, a monitoring study was conducted at the Aquaculture Innovation Center (AIC) of Rutgers University. The AIC is an important hatchery supporting the New Jersey oyster aquaculture industry through the production of disease resistant seed oysters. Starting in June of 2014, temperature, salinity, dissolved oxygen and pH were continuously monitored at the AIC's intake pipe. Periodic grab samples were also collected at the intake and at locations within the facility. Grab samples were preserved and analyzed for pH and dissolved inorganic carbon (DIC). DIC and pH were used to calculate the aragonite saturation state of the sampled water. During an upwelling event in early July a drop in pH was measured at the intake. Grab samples showed that water of lower pH and aragonite saturation was entering the facility. These results show that hatcheries along the NJ coast need to be aware that upwelling events may bring conditions detrimental for shellfish production.

  13. Survey of subsistence fish and shellfish for exposure to oil spilled from the Exxon Valdez. First year: 1989. Technical memo

    SciTech Connect

    Varanasi, U.; Chan, S.L.; MacLeod, W.D.; Stein, J.E.; Brown, D.W.

    1990-12-01

    More than 500 fish and shellfish samples collected from native Alaskan fishing grounds were analyzed for aromatic contaminants (ACs) from petroleum (alkylated and unsubstituted aromatic hydrocarbons with 2-7 benzenoid rings and dibenzothiophenes). Intertidal molluscs (mussels, clams, chitons, and snails) from Windy Bay, Kodiak (City), Chenega Bay, and Old Harbor consistently had more than 100 parts-per-billion (ppb) ACs, with levels in mussels from Windy Bay and Kodiak as high as 12,000 to 18,000 ppb. Levels of ACs in molluscs, crabs, and sea urchins from other villages were less than 10 ppb, a level comparable to that measured in shellfish from the designated reference area in Southeast Alaska near Angoon. Nonparametric statistics on 147 samples of molluscs showed that levels of ACs in molluscs from Windy Bay, Kodiak, and Chenega Bay were significantly higher (p = or < 0.05) than those in the Angoon molluscs sampled. In an unofficial advisory opinion, the Food and Drug Administration has indicated that little risk is involved in the consumption of the nonsmoked subsistence foods studied.

  14. Fluorogenic Membrane Overlays to Enumerate Total and Fecal Escherichia coli and Total Vibrionaceae in Shellfish and Seawater.

    PubMed

    Richards, Gary P; Watson, Michael A

    2010-01-01

    Three assays were developed to enumerate total and fecal Escherichia coli and total Vibrionaceae in shellfish, seawater, and other foods and environmental samples. Assays involve membrane overlays of overnight colonies on nonselective agar plates to detect beta-glucuronidase and lysyl aminopeptidase activities for E. coli and Vibrionaceae, respectively. Cellulose membranes containing the substrates 4-methylumbeferyl-beta-D-glucuronide (MUG) produced a bright blue fluorescence when overlaid onto E. coli, while L-lysyl-7-amino-4-trifluoromethylcoumarin produced green fluorescent foci when overlaid onto Vibrionaceae family members. A multiplex assay was also developed for simultaneously enumerating total E. coli and total Vibrionaceae in oysters and seawater. Overall, 65% of overlaid E. coli (non-O157:H7) were MUG-positive, compared with 62% as determined by the most-probable-number-MUG assay. The overlays are rapid, simple, and cost effective for quantification purposes. This research provides practical alternatives for monitoring bacterial indicators and potential pathogens in complex samples, including molluscan shellfish. PMID:20396663

  15. Relation of fish and shellfish distributions to habitat and water quality in the Mobile Bay estuary, USA.

    PubMed

    Rashleigh, Brenda; Cyterski, Mike; Smith, Lisa M; Nestlerode, Janet A

    2009-03-01

    The Mobile Bay estuary in the northern Gulf of Mexico provides a rich habitat for many fish and shellfish, including those identified as economically and ecologically important. The National Estuary Program in Mobile Bay has focused on restoration of degraded estuarine habitat on which these species depend. To support this effort, we used statistical techniques of ordination, cluster analysis, and discriminant analysis to relate distributions of individual fish and shellfish species and species assemblages to two dozen water quality and habitat variables in a geo-referenced database. Species appeared to respond to dominant gradients of low to high salinity and upland to offshore habitat area; many of the 15 communities identified via cluster analysis showed aggregated spatial distributions that could be related to habitat characteristics. Species in the Mobile River Delta were distinct from those in other areas of the estuary. This analysis supports habitat management in the Mobile Bay estuary; however, due to mobility of organisms among sampling locations and the dynamic environmental conditions in estuaries, we conclude that the analyses presented here are most appropriate for an evaluation of the estuary as a whole. PMID:19083112

  16. Analytical methodology for the determination of Kepone residues in fish, shellfish, and Hi-Vol air filters.

    PubMed

    Hodgson, D W; Kantor, E J; Mann, J B

    1978-01-01

    The recent discovery of the pollution of the environment with Kepone has resulted in a tremendous interest in the development of residue methodology for the compound. Current multiresidue methods for the determination of the common organochlorinated pesticides do not yield good quantitative analytical results for Kepone. The extracting solvents are usually of insufficient polarity to extract Kepone from the various media. This article describes some of the recently developed methodology for Kepone in air filters, finfish, finfish livers and entrails, shellfish, and archival oyster samples. The finfish and archival oyster samples were Soxhlet extracted using diethyl ether/petroleum ether (1:1 v/v) as the extracting solvent. The finfish livers and entrails were macerated in a Duall tissue grinder containing acetonitrile followed by partitioning of the Kepone into benzene. Shellfish samples were analyzed after extracting the sample with acetonitrile and partitioning the Kepone into benzene. The Hi-Vol air samples were extracted with methanol/benzene (1:1 v/v). The coextracting contaminants were removed by micro-Florisil column chromatography and/or acid digestion. The procedural recovery of Kepone from fortified samples averaged 82%. PMID:78687

  17. [Modeling the occurrence of shellfish poisoning outbreaks caused by Gymnodinium catenatum (Dinophyceae) through electromagnetic signal triggering].

    PubMed

    Vale, Pulo

    2014-01-01

    Accumulation of paralytic shellfish poisoning toxins (PSTs) in bivalves attributed to Gymnodinium catenatum blooms at the NW Portuguese coast was previously associated with periods of low solar activity (measured by the radio flux [R]), or low geomagnetic A(a) index. It was also observed that reduction of R preceded the occurrence of toxin accumulation, while A(a) index increase could be related to its absence during periods of low activity. For modeling toxin accumulation, the monthly decrease in R was studied along the decade 2003-2012. A match that helped explaining the highly toxic years of 2007 and 2008 was obtained by plotting the formula: ?R = (R(n-1) - R(n))/(R(n) - 65)2, where 65 represented the lowest radio activity known to date. The complex denominator was required to take into account the sunspot cycle. A 1-2 month lag was observed between maximal relative decline and maximal PSTs accumulation. PSTs in bivalves from the Portuguese south coast were related with natural electromagnetic cycles for the first time, and were not statistically associated with low R. A statistically significant association with low A(a) index also was not achieved, due to the low number of occurrences, although the 25-75 percentile was restricted to low Aa indexes in a similar way to that found for the NW coast. PSTs accumulation outside solar minima could be triggered by a steep decline in the A(a) index (?A), but no lag was observed in this case. While ?R amplitude helped explaining the highly toxic years of 2007 and 2008 at the NW coast, the amplitude of ?A was not related to the severity of the accumulation. Other kind of local electromagnetic signaling was investigated resorting to the occurrence of seismologic phenomena, because these events can trigger electric activities. No statistical association was found between seism number or magnitude and PSTs at the south coast, located near the boundary between the African and Eurasian plates, and marked by moderate seismicity. PMID:25715602

  18. In Silico Analysis of Putative Paralytic Shellfish Poisoning Toxins Export Proteins in Cyanobacteria

    PubMed Central

    Soto-Liebe, Katia; Lpez-Corts, Xaviera A.; Fuentes-Valdes, Juan Jos; Stucken, Karina; Gonzalez-Nilo, Fernando; Vsquez, Mnica

    2013-01-01

    Paralytic shellfish poisoning toxins (PSTs) are a family of more than 30 natural alkaloids synthesized by dinoflagellates and cyanobacteria whose toxicity in animals is mediated by voltage-gated Na+ channel blocking. The export of PST analogues may be through SxtF and SxtM, two putative MATE (multidrug and toxic compound extrusion) family transporters encoded in PSTs biosynthetic gene cluster (sxt). sxtM is present in every sxt cluster analyzed; however, sxtF is only present in the Cylindrospermopsis-Raphidiopsis clade. These transporters are energetically coupled with an electrochemical gradient of proton (H+) or sodium (Na+) ions across membranes. Because the functional role of PSTs remains unknown and methods for genetic manipulation in PST-producing organisms have not yet been developed, protein structure analyses will allow us to understand their function. By analyzing the sxt cluster of eight PST-producing cyanobacteria, we found no correlation between the presence of sxtF or sxtM and a specific PSTs profile. Phylogenetic analyses of SxtF/M showed a high conservation of SxtF in the Cylindrospermopsis-Raphidiopsis clade, suggesting conserved substrate affinity. Two domains involved in Na+ and drug recognition from NorM proteins (MATE family) of Vibrio parahaemolyticus and V. cholerae are present in SxtF/M. The Na+ recognition domain was conserved in both SxtF/M, indicating that Na+ can maintain the role as a cation anti-transporter. Consensus motifs for toxin binding differed between SxtF and SxtM implying differential substrate binding. Through protein modeling and docking analysis, we found that there is no marked affinity between the recognition domain and a specific PST analogue. This agrees with our previous results of PST export in R. brookii D9, where we observed that the response to Na+ incubation was similar to different analogues. These results reassert the hypothesis regarding the involvement of Na+ in toxin export, as well as the motifs L398XGLQD403 (SxtM) and L390VGLRD395 (SxtF) in toxin recognition. PMID:23457475

  19. Toxic effects, pharmacokinetics and clearance of saxitoxin, a component of paralytic shellfish poison (PSP), in cats.

    PubMed

    Andrinolo, D; Michea, L F; Lagos, N

    1999-03-01

    Saxitoxin (STX) was the first known and most studied toxic component of paralytic shellfish poisoning (PSP). This toxin blocks neuronal transmission by binding to the voltage-gated Na+ channel. Although the toxin's mechanism of action is well known at the molecular level, there are still many unresolved questions about its pharmacokinetics and the PSP intoxication syndrome in mammals. Some of these questions are addressed in the present paper, which describes an experimental design which allowed us to follow the dynamics of STX poisoning in vivo. Adult cats were anaesthetized and permanently coupled to artificial ventilation, they were then intravenously injected with Low (2.7 microg of STX/kg) and high doses (10 microg of STX/kg) of toxin. Cardiovascular parameters such as blood pressure and electrocardiograms were recorded, urine and blood samples were collected during the four hours of experimental time. In order to quantify mass amount of STX, we used the post-column derivatization HPLC method. Urine and blood samples were cleansed using a C-18 Sep-Pack cartridge and ultrafree microcentrifuge filters. At the end of each experiment, the animals were killed and tissue samples from brain, liver, spleen and medulla oblongata were extracted to measure the amount of STX. As compared to control period, Low doses of STX made no difference in hemodynamics parameters. In contrast, high doses drastically reduced blood pressure, produced myocardial failure and finally cardiac arrest. Administration of 2.5 microg/kg x min of dobutamine restored hemodynamics parameters and allowed the animal to overcome the shock. With high doses, the calculated STX renal clearance in cats is 0.81 ml/min x kg(-1). This valued corresponds to 20.25% of the reported inulin renal clearance. Nevertheless with Low doses the STX renal clearance is 3.99 ml/min x kg(-1). This data suggest that in cats with normal cardiovascular parameters and diuresis, the STX excretion mainly involves glomerular filtration. During experimental time, no PSP toxins other than STX was detected in the body fluids and tissue samples analyzed, indicating that the mammals can not metabolize this molecule. STX was found in intensely irrigated organs such as the liver and spleen but also in the central nervous system (brain and medulla oblongata), showing that STX was capable of crossing the blood brain barrier. PMID:10080350

  20. Temperature effects on kinetics of paralytic shellfish toxin elimination in Atlantic surfclams, Spisula solidissima

    NASA Astrophysics Data System (ADS)

    Monica Bricelj, V.; Cembella, Allan D.; Laby, David

    2014-05-01

    Surfclams, Spisula solidissima, pose a particular health risk for human consumption as they are characterized by accumulation of extremely high levels of toxins associated with paralytic shellfish poisoning (PSP), slow toxin elimination and an extremely high post-ingestive capacity for toxin bioconversion. Surfclam populations experience a wide range of temperatures along the NW Atlantic continental shelf, and are undergoing range contraction that has been attributed to global warming. In this study the influence of temperature (5, 12 and 21 °C) on detoxification kinetics of individual PSP toxins in two tissue compartments of juvenile surfclams (∼35 mm shell length) was determined under controlled laboratory conditions, over prolonged (2.4 months) depuration. Clams were toxified with a representative regional Gulf of Maine isolate of the dinoflagellate Alexandrium fundyense of known toxin profile, allowing tracking of changes in toxin composition and calculated toxicity in surfclam tissues. The visceral mass detoxified at all temperatures, although toxin loss rate increased with increasing temperature. In contrast, total toxin content and calculated toxicities in other tissues remained constant or even increased during depuration, suggesting a physiological or biochemical toxin-retention mechanism in this tissue pool and temperature-independent detoxification. In vivo toxin compositional changes in surfclam tissues found in this study provide evidence of specific toxin conversion pathways, involving both reductive and decarbamoylation pathways. We conclude that such toxin biotransformations, especially in non-visceral tissues, may introduce a discrepancy in describing kinetics of total toxicity (in saxitoxin equivalents [STXeq]) of S. solidissima over prolonged detoxification. Nevertheless, use of total toxicity values generated by routine regulatory monitoring based upon mouse bioassays or calculated from chemical analytical determination of molar toxin concentrations is adequate for first-order modeling of toxin kinetics in this species. Furthermore, the differential detoxification response of viscera and other tissues in relation to temperature emphasizes the need for two-compartment modeling to describe the fate of PSP toxins in this species. Finally, key parameters were identified that may prove useful in hindcasting the timing of toxic blooms or new toxin input in deep offshore waters where routine monitoring of toxic phytoplankton is impractical.

  1. The Seasonality of Fecal Coliform Bacteria Pollution and its Influence on Closures of Shellfish Harvesting Areas in Mississippi Sound

    PubMed Central

    Chigbu, Paulinus; Gordon, Scott; Tchounwou, Paul B.

    2005-01-01

    Runoff from agricultural lands and farm animal feedlots is one of the major sources of fecal coliforms in surface waters, and fecal coliform (FC) bacteria concentrations tend to vary with season because of seasonal variations in climatic factors. However, El Niño -Southern Oscillation (ENSO) events may affect the extent and patterns of seasonality in FC levels in coastal waters. Water quality monitoring data for shellfish management collected during El Niño (1990, 1992, 1997), and La Niña (1999, 2000) years were analyzed to evaluate the extent to which these events influenced Pearl River stage, and bacterial levels, water temperature, and salinity in the western part of Mississippi Sound. Models to predict FC levels in relation to various environmental factors were also developed. In 1990, 1992 and 1997, FC geometric mean counts peaked in late winter (January/February) reaching 120 MPN (February 1990), 165 MPN (January 1992), and 86 MPN (January 1997), and then decreased considerably during spring and summer (1.2 – 19 MPN). Thereafter, FC abundance increased slightly in fall and early winter (1.9 – 24 MPN). Fecal coliform abundance during the 2000 La Niña year was much lower (1.0 – 10.3 MPN) than in 1992 (1.2 – 165 MPN), and showed no seasonal pattern from January to August, perhaps due to the relative scarcity of rainfall in 2000. In 1995 (ENSO neutral year), peak geometric mean FC count (46 MPN) was lower than during El Niño years and occurred in early spring (March). The seasonal and between year variations in FC levels determined the number of days during which the conditionally approved shellfish growing area was opened for harvesting shellfish. For example, from January to April 1997, the area was not opened for shellfish harvesting, whereas in 2000, the number of days during which the area was opened ranged from 6 – 27 (January to April) to 24 – 26 (October to December). ENSO events thus influenced the extent and timing of the peak levels of fecal coliforms in Mississippi Sound. Models consisting of one or more of the variables: Pearl River stage, water temperature, and salinity were developed to predict FC concentrations in the Sound. The model parameter(s) explained 56 to 91% of the variations in FC counts. Management of shellfish in Mississippi Sound can be improved by utilizing information on the forecasted three to seven years occurrence of ENSO events. In addition, since Pearl River stage was the most important variable predicting FC concentration in the Sound, a study of the levels and sources of FC bacteria in the river, especially the middle and lower sections, is needed for developing a management plan for reducing FC bacteria pollution in the Sound. PMID:16705840

  2. Rapid and Sensitive Detection of Noroviruses by Using TaqMan-Based One-Step Reverse Transcription-PCR Assays and Application to Naturally Contaminated Shellfish Samples

    PubMed Central

    Jothikumar, Narayanan; Lowther, James A.; Henshilwood, Kathleen; Lees, David N.; Hill, Vincent R.; Vinj, Jan

    2005-01-01

    Noroviruses (NoV), which are members of the family Caliciviridae, are the most important cause of outbreaks of acute gastroenteritis worldwide and are commonly found in shellfish grown in polluted waters. In the present study, we developed broadly reactive one-step TaqMan reverse transcription (RT)-PCR assays for the detection of genogroup I (GI) and GII NoV in fecal samples, as well as shellfish samples. The specificity and sensitivity of all steps of the assays were systematically evaluated, and in the final format, the monoplex assays were validated by using RNA extracted from a panel of 84 stool specimens, which included NoV strains representing 19 different genotypes (7 GI, 11 GII, and 1 GIV strains). The assays were further validated with 38 shellfish cDNA extracts previously tested by nested PCR. Comparison with a recently described real-time assay showed that our assay had significantly higher sensitivity and was at least as sensitive as the nested PCR. For stool specimens, a one-step duplex TaqMan RT-PCR assay performed as well as individual genogroup-specific monoplex assays. All other enteric viruses examined were negative, and no cross-reaction between genogroups was observed. These TaqMan RT-PCR assays provide rapid (less than 90 min), sensitive, and reliable detection of NoV and should prove to be useful for routine monitoring of both clinical and shellfish samples. PMID:15812014

  3. Detection of Diarrheic Shellfish Poisoning and Azaspiracid Toxins in Moroccan Mussels: Comparison of the LC-MS Method with the Commercial Immunoassay Kit

    PubMed Central

    Elgarch, Adra; Vale, Paulo; Rifai, Saida; Fassouane, Aziz

    2008-01-01

    Diarrheic shellfish poisoning (DSP) is a recurrent gastrointestinal illness in Morocco, resulting from consumption of contaminated shellfish. In order to develop a rapid and reliable technique for toxins detection, we have compared the results obtained by a commercial immunoassay-DSP-Check kit with those obtained by LC-MS. Both techniques are capable of detecting the toxins in the whole flesh extract which was subjected to prior alkaline hydrolysis in order to detect simultaneously the esterified and non esterified toxin forms. The LC-MS method was found to be able to detect a high level of okadaic acid (OA), low level of dinophysistoxin-2 (DTX2), and surprisingly, traces of azaspiracids 2 (AZA2) in mussels. This is the first report of a survey carried out for azaspiracid (AZP) contamination of shellfish harvested in the coastal areas of Morocco. The DSP-Check kit was found to detect quantitatively DSP toxins in all contaminated samples containing only OA, provided that the parent toxins were within the range of detection and was not in an ester form. A good correlation was observed between the two methods when appropriate dilutions were performed. The immunoassay kit appeared to be more sensitive, specific and faster than LC-MS for determination of DSP in total shellfish extract. PMID:19172196

  4. Possible Influence of Natural Events on Heavy Metals Exposure from Shellfish Consumption: A Case Study in the North-East of Italy

    PubMed Central

    Losasso, Carmen; Bille, Laura; Patuzzi, Ilaria; Lorenzetto, Monica; Binato, Giovanni; Dalla Pozza, Manuela; Ferrè, Nicola; Ricci, Antonia

    2015-01-01

    The objective of this study was the estimation of the exposure over time to heavy metals (cadmium, mercury, and lead) due to shellfish consumption in the Veneto Region, Italy. Shellfish consumption was investigated by a food frequency consumption survey. Altogether, 1949 households, stratified into the five most populated areas of the Veneto Region, were involved in the study. Exposure estimation to heavy metals was carried out taking into account the level of metal measured in samples of Manila clams (Ruditapes philippinarum) and grooved carpet shell (Ruditapes decussatus), collected in the frame of the monitoring activities of mollusk production areas of Veneto Region, between January 2007 and December 2012. A general high contribution of the considered shellfish to the Tolerable Weekly Intake was noticed in the case of cadmium, especially in 2011, when a considerable increase in cadmium intake was estimated. This was probably due to a heavy rainfall event that triggered catastrophic flooding with high impact on shellfish capture areas in November 2010. The results strongly emphasize the importance of dealing with food safety in a holistic way, taking into account the potential impact of extraordinary natural events on food chain contamination, in order to identify food hazards at an early stage, before developing into a real risk for consumers. PMID:25699249

  5. Clean and safe supply of fish and shellfish to clear the HACCP regulation by use of clean and cold deep ocean water in Rausu, Hokkaido, Japan

    NASA Astrophysics Data System (ADS)

    Mac Takahashi, Masayuki; Yamashita, Kazunori

    2005-07-01

    For the supply of fish and shellfish to consumers in fresh condition, clean handling after catch from the sea is essential. According to HACCP (Hazard Analysis and Critical Control Points), it is important to meet such requirement by keeping fish and shellfish under a certain low temperature and clean conditions after catching. The deep ocean water (DOW) characterized by low temperature and cleanliness has been chosen for fish and shellfish handlings, particularly for salmon, cod, and sea urchin in Town Rausu in Hokkaido, Japan. DOW below 2.9C of an amount of nearly 5 000m3 is planned to be pumped up every day from a depth of about 350 m, and temporarily stored in a large simulated tank on land. DOW is then supplied to fish boats through hydrants distributed throughout the harbor and used for keeping salmon in clean and cold conditions. Ice made from DOW is also used for lowering temperature if necessary. DOW and ice made from DOW are also used during the transportation of fish and shellfish. The entire system is scheduled to be completed by the summer of 2005.

  6. Possible influence of natural events on heavy metals exposure from shellfish consumption: a case study in the north-East of Italy.

    PubMed

    Losasso, Carmen; Bille, Laura; Patuzzi, Ilaria; Lorenzetto, Monica; Binato, Giovanni; Dalla Pozza, Manuela; Ferr, Nicola; Ricci, Antonia

    2015-01-01

    The objective of this study was the estimation of the exposure over time to heavy metals (cadmium, mercury, and lead) due to shellfish consumption in the Veneto Region, Italy. Shellfish consumption was investigated by a food frequency consumption survey. Altogether, 1949 households, stratified into the five most populated areas of the Veneto Region, were involved in the study. Exposure estimation to heavy metals was carried out taking into account the level of metal measured in samples of Manila clams (Ruditapes philippinarum) and grooved carpet shell (Ruditapes decussatus), collected in the frame of the monitoring activities of mollusk production areas of Veneto Region, between January 2007 and December 2012. A general high contribution of the considered shellfish to the Tolerable Weekly Intake was noticed in the case of cadmium, especially in 2011, when a considerable increase in cadmium intake was estimated. This was probably due to a heavy rainfall event that triggered catastrophic flooding with high impact on shellfish capture areas in November 2010. The results strongly emphasize the importance of dealing with food safety in a holistic way, taking into account the potential impact of extraordinary natural events on food chain contamination, in order to identify food hazards at an early stage, before developing into a real risk for consumers. PMID:25699249

  7. Assessing and managing the health risk due to ingestion of inorganic arsenic from fish and shellfish farmed in blackfoot disease areas for general Taiwanese.

    PubMed

    Liang, Ching-Ping; Liu, Chen-Wuing; Jang, Cheng-Shin; Wang, Sheng-Wei; Lee, Jin-Jing

    2011-02-15

    This paper assesses health risks due to the ingestion of inorganic arsenic from fish and shellfish farmed in blackfoot disease areas by general public in Taiwan. The provisional tolerable weekly intake of arsenic set by FAO/WHO and the target cancer risk assessment model proposed by USEPA were integrated to evaluate the acceptable consumption rate. Five aquacultural species, tilapia (Oreochromis mossambicus), milkfish (Chanos chanos), mullet (Mugil cephalus), clam (Meretrix lusoria) and oyster (Crassostrea gigas) were included. Monte Carlo analysis was used to propagate the parameter uncertainty and to probabilistically assess the health risk associated with the daily intake of inorganic As from farmed fish and shellfish. The integrated risk-based analysis indicates that the associated 50th and 95th percentile health risk are 2.0610(-5) and 8.7710(-5), respectively. Moreover, the acceptable intakes of inorganic As are defined and illustrated by a two dimensional graphical model. According to the relationship between C(inorg) and IR(f) derived from this study, two risk-based curves are constructed. An acceptable risk zone is determined (risk ranging from 110(-5) to 6.0710(-5)) which is recommended for acceptable consumption rates of fish and shellfish. To manage the health risk due to the ingestion of inorganic As from fish and shellfish in BFD areas, a risk-based management scheme is derived which provide a convenient way for general public to self-determine the acceptable seafood consumption rate. PMID:21134715

  8. Development of a sensitive and selective liquid chromatography-mass spectrometry method for high throughput analysis of paralytic shellfish toxins using graphitised carbon solid phase extraction.

    PubMed

    Boundy, Michael J; Selwood, Andrew I; Harwood, D Tim; McNabb, Paul S; Turner, Andrew D

    2015-03-27

    Routine regulatory monitoring of paralytic shellfish toxins (PST) commonly employs oxidative derivitisation and complex liquid chromatography fluorescence detection methods (LC-FL). The pre-column oxidation LC-FL method is currently implemented in New Zealand and the United Kingdom. When using this method positive samples are fractionated and two different oxidations are required to confirm the identity and quantity of each PST analogue present. There is a need for alternative methods that are simpler, provide faster turnaround times and have improved detection limits. Hydrophilic interaction liquid chromatography (HILIC) HPLC-MS/MS analysis of PST has been used for research purposes, but high detection limits and substantial sample matrix issues have prevented it from becoming a viable alternative for routine monitoring purposes. We have developed a HILIC UPLC-MS/MS method for paralytic shellfish toxins with an optimised desalting clean-up procedure on inexpensive carbon solid phase extraction cartridges for reduction of matrix interferences. This represents a major technical breakthrough and allows sensitive, selective and rapid analysis of paralytic shellfish toxins from a variety of sample types, including many commercially produced bivalve molluscan shellfish species. Additionally, this analytical approach avoids the need for complex calculations to determine sample toxicity, as unlike other methods each PST analogue is able to be quantified as a single resolved peak. This article presents the method development and optimisation information. A thorough single laboratory validation study has subsequently been performed and this data will be presented elsewhere. PMID:25704772

  9. Paralytic shellfish toxins in clinical matrices: Extension of AOAC official method 2005.06 to human urine and serum and application to a 2007 case study in Maine

    NASA Astrophysics Data System (ADS)

    DeGrasse, Stacey; Rivera, Victor; Roach, John; White, Kevin; Callahan, John; Couture, Darcie; Simone, Karen; Peredy, Tamas; Poli, Mark

    2014-05-01

    Paralytic shellfish poisoning (PSP), a potentially fatal foodborne illness, is often diagnosed anecdotally based on symptoms and dietary history. The neurotoxins responsible for PSP, collectively referred to as the saxitoxins or paralytic shellfish toxins (PSTs), are natural toxins, produced by certain dinoflagellates, that may accumulate in seafood, particularly filter-feeding bivalves. Illnesses are rare because of effective monitoring programs, yet occasional poisonings occur. Rarely are contaminated food and human clinical samples (e.g., urine and serum) available for testing. There are currently few methods, none of which are validated, for determining PSTs in clinical matrices. This study evaluated AOAC (Association of Analytical Communities) Official Method of Analysis (OMA) 2005.06. [AOAC Official Method 2005.06 Paralytic Shellfish Poisoning Toxins in Shellfish: Prechormatographic Oxidation and Liquid Chromatography with Fluorescence Detection. In Official Methods of Analysis of AOAC International ], validated only for shellfish extracts, for its extension to human urine and serum samples. Initial assessment of control urine and serum matrices resulted in a sample cleanup modification when working with urine to remove hippuric acid, a natural urinary compound of environmental/dietary origin, which co-eluted with saxitoxin. Commercially available urine and serum matrices were then quantitatively spiked with PSTs that were available as certified reference materials (STX, dcSTX, B1, GTX2/3, C1/2, NEO, and GTX1/4) to assess method performance characteristics. The method was subsequently applied successfully to a PSP case study that occurred in July 2007 in Maine. Not only were PSTs identified in the patient urine and serum samples, the measured time series also led to the first report of human PST-specific urinary elimination rates. The LC-FD data generated from this case study compared remarkably well to results obtained using AOAC OMA 2011.27 [AOAC Official Method 2011.27 Paralytic Shellfish Toxins (PSTs) in Shellfish, Receptor Binding Assay. In Official Methods of Analysis of AOAC International ], further demonstrating successful extension of the LC-FD method to these clinical matrices. Moreover, data generated from this poisoning event reiterated that urine is a preferable clinical matrix, compared to serum, for diagnostic purposes due to higher accumulation and longer residence times in urine.

  10. Evidence of in vitro glucuronidation and enzymatic transformation of paralytic shellfish toxins by healthy human liver microsomes fraction.

    PubMed

    Garca, Carlos; Rodriguez-Navarro, Alberto; Daz, Juan Carlos; Torres, Rafael; Lagos, Nstor

    2009-02-01

    Paralytic Shellfish Toxins (PST) are endemic components found in filter bivalves in Southern Chile. Post-mortems analysis of fluid and tissue samples has shown biotransformation of PST in humans. The Gonyautoxin 3 (GTX3) and Gonyautoxin 2 (GTX2) are the major PST components in the toxin profile found in Chilean shellfish extracts, being as much as 65% of the total content of PST in filter bivalves. Therefore, they are the major accountable components of the human intoxication by shellfish consumption. The aim of this study is to show in vitro glucuronidation and biotransformation of GTX3 and GTX2 when they are incubated with microsomal fraction isolated from healthy human livers. Microsomes fractions isolated from human livers were incubated with GTX3 and GTX2 purified from contaminated mussels. After different incubation times, incubated samples were extracted and analyzed by HPLC with fluorescent on line detection and HPLC-MS analysis. The results revealed that GTX3 and GTX2, only when they were incubated with microsomal fraction and appropriated cofactors, showed to be enzymatic transformed in vitro. The glucuronidation of GTX3 and GTX2 followed typical Michaelis-Menten kinetics, resulting in apparent kinetic parameters of Km=39.4+/-0.24 microM and Vmax=6.0x10(-3) pmol/min/mg protein. In addition, the microsomes fraction also oxidized GTX3 and GTX2 into Gonyautoxin 4 (GTX 4) and Gonyautoxin 1 (GTX 1) resulting in 0.339x10(-3) pmol/min/mg protein. In conclusion, this study reports oxidation and glucuronidation of GTX3 and GTX2 when they are incubated with human liver microsomal fraction. The metabolism occurs via a glucuronidation reaction, the basis first step of biotransformation in human liver. Also it is showed that GTX4 and GTX1 came by biotransformation from GTX3 and GTX2 in humans. This data confirm human biotransformation found in human post-mortem fluid and tissue samples described previously. This data is the first evidence of in vitro glucuronidation of PST, given a metabolic pathway of detoxification and excretion of PST in human. PMID:19041885

  11. Determination of essential elements (copper, manganese, selenium and zinc) in fish and shellfish samples. Risk and nutritional assessment and mercury-selenium balance.

    PubMed

    Olmedo, P; Hernández, A F; Pla, A; Femia, P; Navas-Acien, A; Gil, F

    2013-12-01

    Fish and shellfish are an important source not only of toxic heavy metals, but also of essential elements in the diet. In this study, levels of Cu, Mn, Se and Zn have been determined in fresh, canned and frozen fish and shellfish products. A total of 485 samples of the 43 most frequently consumed fish and shellfish species in Andalusia (Southern Spain) were analyzed for essential elements content. The potential human health risks for the consumers and the nutritional value of the products analyzed were assessed. Furthermore, the mercury-selenium ratios and the selenium health benefit value (Se-HBVs) were calculated. The highest concentrations of Cu were found in crustaceans species (shrimp and prawn) as they have hemocyanin (a copper-containing protein) that functions as an oxygen-transport molecule. Mn levels were higher in canned bivalve molluscs, such as cockle and clam, and in fresh common sole. Concerning Se, two fresh predatory fish species (tuna and swordfish) presented the most remarkable concentrations of this element. The highest concentration of the essential metals analysed was found for Zn, especially in fresh and canned mussels. All the species analyzed showed beneficial Hg:Se ratios and Se-HBVs, except for the shark species (blue shark and cat shark) and gilt-head bream because of their high Hg levels and low Se content, respectively. Nevertheless, the biomagnification usually observed in hazardous metals such as Hg would not occur for the essential elements measured in predatory species. The estimated daily intakes of the elements studied represented very low percentages of their reference values, ranging from 0.1% (Se) to 3.9% (Cu) for person weighting 60 kg, so the intake of these elements through fish and shellfish would not pose any risk for the average consumer. Moreover, the contribution of fish and shellfish products to the recommended daily allowances and adequate intakes of these mineral elements ranges from 2.5% (Mn) to 25.4% (Se). PMID:24007738

  12. Differentiation of fecal Escherichia coli from human, livestock, and poultry sources by rep-PCR DNA fingerprinting on the shellfish culture area of East China Sea.

    PubMed

    Ma, Hong-Jia; Fu, Ling-Lin; Li, Jian-Rong

    2011-05-01

    The rep-PCR DNA fingerprinting performed with REP, BOX A1R, and (GTG)(5) primers was investigated as a way to differentiate between human, livestock, and poultry sources of fecal pollution on the area of Xiangshan Bay, East China Sea. Of the three methods, the BOX-PCR DNA fingerprints analyzed by jack-knife algorithm were revealed high rate of correct classification (RCC) with 91.30, 80.39, 89.39, 86.14, 93.24, 87.72, and 89.28% of human, cattle, swine, chicken, duck, sheep, and goose E. coli isolates classified into the correct host source, respectively. The average rate of correct classification (ARCC) of REP-, BOX-, and (GTG)(5)-PCR patterns was 79.88, 88.21, and 86.39%, respectively. Although the highest amount of bands in (GTG)(5)-PCR fingerprints could be observed, the discriminatory efficacy of BOX-PCR was superior to both REP- and (GTG)(5)-PCR. Moreover, the similarity of 459 isolates originated from shellfish and growing water was compared with fecal-obtained strains. The results showed that 92.4 and 96.2% E. coli strains isolated from midstream and downstream shellfish samples, respectively, had a ? 80% similarity with corresponding strains isolated from fecal samples. It was indicated that E. coli in feces could spread from human sewage or domestic farms to the surrounding shellfish culture water, and potentially affect the quality of shellfish. This work suggests that rep-PCR fingerprinting can be a promising genotypic tool applied in the shellfish growing water management on East China Sea for source identification of fecal pollution. PMID:21279641

  13. Comparison of toxicity between saxitoxin and decarbamoyl saxitoxin in the mouse bioassay for paralytic shellfish poisoning toxins.

    PubMed

    Suzuki, Hodaka; Machii, Kenji

    2014-11-01

    The mouse bioassay (MBA) for paralytic shellfish poisoning (PSP) toxins has been used in the AOAC Official Method and the official Japanese method. In the AOAC Official Method, the saxitoxin (STX) standard provided by the U.S. Food and Drug Administration (FDA) is used, but no standard is used in the official Japanese method. The objective of this study was to compare the toxicity of decarbamoyl STX (dcSTX), one of the derivatives of STX and a candidate standard for the MBA for PSP toxins in Japan, to that of FDA STX in the MBA platform. In this study, the toxicity of dcSTX was 918.0 44.9 mouse units/mol, and the relative toxicity ratio of dcSTX to FDA STX based on moles was 0.478. PMID:25213205

  14. Synthesis of a tricyclic bisguanidine compound structurally related to saxitoxin and its identification in paralytic shellfish toxin-producing microorganisms.

    PubMed

    Tsuchiya, Shigeki; Cho, Yuko; Konoki, Keiichi; Nagasawa, Kazuo; Oshima, Yasukatsu; Yotsu-Yamashita, Mari

    2015-05-18

    We recently reported the chemical synthesis and identification of the genetically predicted biosynthetic intermediates of saxitoxin (STX), including a 2-aminoimidazole-bearing monoguanidine compound (Int-C'2) in two paralytic shellfish toxin (PST)-producing microorganisms. In this study, we achieved the direct conversion of Int-C'2 into a tricyclic bisguanidine compound (called Cyclic-C'), which is structurally related to STX, through oxidative intramolecular guanidine transfer to 2-aminoimidazole catalyzed by Pd/C under basic conditions in air. By using HPLC-MS analysis, Cyclic-C' was also identified in the PST-producing microorganisms, suggesting that Cyclic-C' is either another biosynthetic intermediate or a shunt product of PSTs. In addition, a weak inhibitory activity of Cyclic-C' to the voltage-gated sodium channels was detected by using a cell-based assay. PMID:25873235

  15. Mercury, cadmium and lead levels in samples of the main traded fish and shellfish species in Galicia, Spain.

    PubMed

    Blanco, Sonia Luca; Gonzlez, Jos Carlos; Vieites, Juan M

    2008-01-01

    The presence of mercury, cadmium and lead has been studied in raw and processed fish and shellfish of the main traded species in Galicia (Spain) from at least 40 commercial outlets between January 2002 and October 2003. The results show that, according to European legislation, the products on the market are generally "safe", although the high levels of mercury in swordfish and shark are notable, with 22% of samples (n = 37) over the limit. We also indicate the relatively important contribution to mercury ingestion of widely consumed species, such as tuna, with 25% of samples (n = 378) over 0.25 mg kg?. Cadmium was over the limit (1.0 mg kg?) in 15% of the tested cephalopods (n = 79) and 29% of Chlamys sp. bivalves (n = 17). PMID:24784533

  16. Quantitative determination of fatty acids in marine fish and shellfish from warm water of Straits of Malacca for nutraceutical purposes.

    PubMed

    Abd Aziz, Nurnadia; Azlan, Azrina; Ismail, Amin; Mohd Alinafiah, Suryati; Razman, Muhammad Rizal

    2013-01-01

    This study was conducted to quantitatively determine the fatty acid contents of 20 species of marine fish and four species of shellfish from Straits of Malacca. Most samples contained fairly high amounts of polyunsaturated fatty acids (PUFAs), especially alpha-linolenic acid (ALA, C18:3 n3), eicosapentaenoic acid (EPA, C20:5 n3), and docosahexaenoic acid (DHA, C22:6 n3). Longtail shad, yellowstripe scad, and moonfish contained significantly higher (P < 0.05) amounts of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha-linolenic acid (ALA), respectively. Meanwhile, fringescale sardinella, malabar red snapper, black pomfret, Japanese threadfin bream, giant seaperch, and sixbar grouper showed considerably high content (537.2-944.1 mg/100 g wet sample) of desirable omega-3 fatty acids. The polyunsaturated-fatty-acids/saturated-fatty-acids (P/S) ratios for most samples were higher than that of Menhaden oil (P/S = 0.58), a recommended PUFA supplement which may help to lower blood pressure. Yellowstripe scad (highest DHA, ω - 3/ω - 6 = 6.4, P/S = 1.7), moonfish (highest ALA, ω - 3/ω - 6 = 1.9, P/S = 1.0), and longtail shad (highest EPA, ω - 3/ω - 6 = 0.8, P/S = 0.4) were the samples with an outstandingly desirable overall composition of fatty acids. Overall, the marine fish and shellfish from the area contained good composition of fatty acids which offer health benefits and may be used for nutraceutical purposes in the future. PMID:23509703

  17. Validation of a confirmatory method for lipophilic marine toxins in shellfish using UHPLC-HR-Orbitrap MS.

    PubMed

    Orellana, Gabriel; Vanden Bussche, Julie; Van Meulebroek, Lieven; Vandegehuchte, Michiel; Janssen, Colin; Vanhaecke, Lynn

    2014-09-01

    Lipophilic marine toxins are produced by harmful microalgae and can accumulate in edible filter feeders such as shellfish, leading to an introduction of toxins into the human food chain, causing different poisoning effects. During the last years, analytical methods, based on liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), have been consolidated by interlaboratory validations. However, the main drawback of LC-MS/MS methods remains the limited number of compounds that can be analyzed in a single run. Due to the targeted nature of these methods, only known toxins, previously considered during method optimization, will be detected. Therefore in this study, a method based on ultra-high-performance liquid chromatography coupled to high-resolution Orbitrap mass spectrometry (UHPLC-HR-Orbitrap MS) was developed. Its quantitative performance was evaluated for confirmatory analysis of regulated lipophilic marine toxins in shellfish flesh according to Commission Decision 2002/657/EC. Okadaic acid (OA), dinophysistoxin-1 (DTX-1), pectenotoxin-2 (PTX-2), azaspiracid-1 (AZA-1), yessotoxin (YTX), and 13-desmethyl spirolide C (SPX-1) were quantified using matrix-matched calibration curves (MMS). For all compounds, the reproducibility ranged from 2.9 to 4.9%, repeatability from 2.9 to 4.9%, and recoveries from 82.9 to 113% at the three different spiked levels. In addition, confirmatory identification of the compounds was effectively performed by the presence of a second diagnostic ion ((13)C). In conclusion, UHPLC-HR-Orbitrap MS permitted more accurate and faster detection of the target toxins than previously described LC-MS/MS methods. Furthermore, HRMS allows to retrospectively screen for many analogues and metabolites using its full-scan capabilities but also untargeted screening through the use of metabolomics software. PMID:24939136

  18. Fit-for-purpose shellfish reference materials for internal and external quality control in the analysis of phycotoxins.

    PubMed

    Hess, Philipp; McCarron, Pearse; Quilliam, Michael A

    2007-04-01

    The need for reference materials for quality control of analysis of foodstuffs has been stressed frequently. This has been particularly true in the phycotoxins field, where there is a great shortage of both pure calibration standards and reference materials. Worldwide there are very few independent bodies that produce certified reference materials for phycotoxins, the main producers currently being the National Research Council Canada and the Japanese Food Research Laboratory. Limited availability of contaminated shellfish and algae, as well as the time and knowledge necessary for the production of adequate reference materials, continuously lead to limited editions of certified reference materials and even more limited production of in-house reference materials. The restricted availability of in-house quality control materials promotes the rapid use of the limited certified reference materials, which in turn hampers the production of the suite of materials required globally for complete protection of public health. This paper outlines the various options that analysts can pursue in the use of reference materials for internal and external quality control, with a view to optimising the efforts of both reference materials users and reference materials producers. For this purpose, the logical sequence is reviewed from the discovery of a new bioactive compound in shellfish, through initial method development up to regulation for food safety purposes including accepted reference methods. Subsequently, the requirements for and efforts typically spent in the production and characterisation of laboratory reference materials, certified reference materials and other test materials used in inter-laboratory studies or proficiency testing, in the area of marine biotoxins are evaluated. Particular emphasis is put on practical advice for the preparation of in-house reference materials. The intricate link between reference material characterisation and method performance is outlined to give guidance on the appropriate in-house method validation in the rapidly developing field of phycotoxins. PMID:17004057

  19. Distribution of heavy metals in internal organs and tissues of Korean molluscan shellfish and potential risk to human health.

    PubMed

    Mok, Jong Soo; Kwon, Ji Young; Son, Kwang Tae; Choi, Woo Seok; Kim, Poong Ho; Lee, Tae Seek; Kim, Ji Hoe

    2015-09-01

    Molluscan shellfish (gastropods and bivalves) were collected from major fish markets on the Korean coast and analyzed for mercury by direct Hg analyzer and for other metals, such as cadmium, lead, chromium, silver, nickel, copper and zinc, using inductively coupled plasma mass spectrometry. Distribution of heavy metals in muscles, internal organs and whole tissues were determined and a potential risk assessment was conducted to evaluate their hazard for human consumption. Heavy metals were accumulated significantly higher (P < 0.05) in internal organs than in muscles for all species. The mean Cd level, which had the highest level of three hazardous metals (Cd, Pb, and Hg) in all internal-organ samples were above the regulatory limit of Korea and the mean level in whole tissue samples of the selected gastropod species, bay scallop and comb pen shell, exceeded the limit (except in a few cases). The sum of the estimated dietary intake of Cd, Pb and Hg for each part of all tested species accounted for 1.59-16.94, 0.02-0.36, and 0.07-0.16% respectively, of the provisional tolerable daily intake adopted by the Joint FAO/WHO Expert Committee on Food Additives. The hazard index for each part of gastropods and bivalves was below 1.0, however, the maximum HI for internal organs of all analysed species was quite high (0.71). These results suggest that consumption of flesh after removing the internal organs of some molluscan shellfish (all gastropod species, bay scallop and comb pen shell) is a suitable way for reducing Cd exposure. PMID:26521561

  20. Quantitative Determination of Fatty Acids in Marine Fish and Shellfish from Warm Water of Straits of Malacca for Nutraceutical Purposes

    PubMed Central

    Abd Aziz, Nurnadia; Azlan, Azrina; Ismail, Amin; Mohd Alinafiah, Suryati; Razman, Muhammad Rizal

    2013-01-01

    This study was conducted to quantitatively determine the fatty acid contents of 20 species of marine fish and four species of shellfish from Straits of Malacca. Most samples contained fairly high amounts of polyunsaturated fatty acids (PUFAs), especially alpha-linolenic acid (ALA, C18:3 n3), eicosapentaenoic acid (EPA, C20:5 n3), and docosahexaenoic acid (DHA, C22:6 n3). Longtail shad, yellowstripe scad, and moonfish contained significantly higher (P < 0.05) amounts of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha-linolenic acid (ALA), respectively. Meanwhile, fringescale sardinella, malabar red snapper, black pomfret, Japanese threadfin bream, giant seaperch, and sixbar grouper showed considerably high content (537.2944.1?mg/100g wet sample) of desirable omega-3 fatty acids. The polyunsaturated-fatty-acids/saturated-fatty-acids (P/S) ratios for most samples were higher than that of Menhaden oil (P/S = 0.58), a recommended PUFA supplement which may help to lower blood pressure. Yellowstripe scad (highest DHA, ? ? 3/? ? 6 = 6.4, P/S = 1.7), moonfish (highest ALA, ? ? 3/? ? 6 = 1.9, P/S = 1.0), and longtail shad (highest EPA, ? ? 3/? ? 6 = 0.8, P/S = 0.4) were the samples with an outstandingly desirable overall composition of fatty acids. Overall, the marine fish and shellfish from the area contained good composition of fatty acids which offer health benefits and may be used for nutraceutical purposes in the future. PMID:23509703

  1. Minimal incorporation of Deepwater Horizon oil by estuarine filter feeders.

    PubMed

    Fry, Brian; Anderson, Laurie C

    2014-03-15

    Natural abundance carbon isotope analyses are sensitive tracers for fates and use of oil in aquatic environments. Use of oil carbon in estuarine food webs should lead to isotope values approaching those of oil itself, -27 for stable carbon isotopes reflecting oil origins and -1000 for carbon-14 reflecting oil age. To test for transfer of oil from the 2010 Deepwater Horizon spill into estuarine food webs, filter-feeding barnacles (Balanus sp.) and marsh mussels (Geukensia demissa) were collected from Louisiana estuaries near the site of the oil spill. Carbon-14 analyses of these animals from open waters and oiled marshes showed that oil use was <1% and near detection limits estimated at 0.3% oil incorporation. Respiration studies showed no evidence for enhanced microbial activity in bay waters. Results are consistent with low dietary impacts of oil for filter feeders and little overall impact on respiration in the productive Louisiana estuarine systems. PMID:24461698

  2. Predator-prey interactions between blue crabs and ribbed mussels living in clumps

    NASA Astrophysics Data System (ADS)

    Lin, Junda

    1991-01-01

    Predator-prey interactions between blue crabs ( Callinectes sapidus) and ribbed mussels ( Geukensia demissa) were studied by manipulating different components of mussel clump structure in the laboratory to test their effects on the mussels' susceptibility to crab predation. Mussels with stronger attachment strength or those buried deeper in the sediment suffered lower mortality. Blue crabs showed no significant size selectivity when two size classes of mussles (30-40 and 50-60 mm in shell heights) were offered. When juvenile mussels were attached to adult conspecifics and completely buried in the centres of clumps as in the field, blue crabs did not actively search for them. The crabs, however, did consume juveniles as by-products when they preyed upon the adult mussels to which the juveniles were attached.

  3. Multiple stable isotopes used to trace the flow of organic matter in estuarine food webs.

    PubMed

    Peterson, B J; Howarth, R W; Garritt, R H

    1985-03-15

    The use of a combination of the stable isotopes of sulfur, carbon, and nitrogen allows the flow of organic matter and trophic relations in salt marshes and estuaries to be traced while eliminating many ambiguities that accompany the use of a single isotopic tracer. Salt-marsh grasses take up the isotopically light sulfides formed during sulfate reduction, and the transfer of this light sulfur through the marsh food web is illustrated with data on the ribbed mussel (Geukensia demissa) from various locations in a New England marsh. The multiple isotope approach shows that this filter feeder consumes both marsh grass ( Spartina) detritus and plankton, with the relative proportions of each determined by the location of the mussels in the marsh. PMID:17793771

  4. Multiple Stable Isotopes Used to Trace the Flow of Organic Matter in Estuarine Food Webs

    NASA Astrophysics Data System (ADS)

    Peterson, Bruce J.; Howarth, Robert W.; Garritt, Robert H.

    1985-03-01

    The use of a combination of the stable isotopes of sulfur, carbon, and nitrogen allows the flow of organic matter and trophic relations in salt marshes and estuaries to be traced while eliminating many ambiguities that accompany the use of a single isotopic tracer. Salt-marsh grasses take up the isotopically light sulfides formed during sulfate reduction, and the transfer of this light sulfur through the marsh food web is illustrated with data on the ribbed mussel (Geukensia demissa) from various locations in a New England marsh. The multiple isotope approach shows that this filter feeder consumes both marsh grass (Spartina) detritus and plankton, with the relative proportions of each determined by the location of the mussels in the marsh.

  5. Use of two-dimensional gel electrophoresis to differentiate morphospecies of Alexandrium minutum, a paralytic shellfish poisoning toxin-producing dinoflagellate of harmful algal blooms.

    PubMed

    Chan, Leo Lai; Hodgkiss, Ivor John; Lam, Paul Kwan-Sing; Wan, Jennifer Man-Fan; Chou, Hong-Nong; Lum, John Hon-Kei; Lo, Maria Gar-Yee; Mak, Abby Sin-Chi; Sit, Wai-Hung; Lo, Samuel Chun-Lap

    2005-04-01

    Contamination of shellfish with paralytic shellfish poisoning toxins (PST) produced by toxic harmful algal blooms (HABs) have been negatively affecting the shellfish and aquaculture industries worldwide. Therefore, accurate and early identification of toxic phytoplankton species is crucial in HABs surveillance programs that allow fish-farmers to take appropriate preventive measures in shellfish harvesting and other aquaculture activities to overcome the negative impacts of HABs on human health. The identification of toxic dinoflagellates present in the water is currently a time-consuming operation since it requires skillful taxonomists and toxicologists equipped with optical and scanning electron microscopes as well as sophisticated equipment, for example, high-performance liquid chromotography-fluorescence detection. In this paper, a two-dimensional gel electrophoresis (2-DE)-based proteomic approach was applied to discriminate between toxic and nontoxic strains of Alexandrium minutum. Variation in morphological features between toxic and nontoxic strains was minimal and not significant. Also, variation in 2-DE protein patterns within either toxic or nontoxic strains was low, but pronounced differences were detected between toxic and nontoxic strains. The most notable differences between these strains were several abundant proteins with pIs ranging from 4.8 to 5.3 and apparent molecular masses between 17.5 and 21.5 kDa. Groups of proteins, namely NT1, NT2, NT3, and NT4, were consistently found in all nontoxic strains, while T1 and T2 were prominent in the toxic strains. These specific protein spots characteristic for toxic and nontoxic strains remained clearly distinguishable irrespective of the various growth conditions tested. Therefore, they have the potential to serve as "taxonomic markers" to distinguish toxic and nontoxic strains within A. minutum. Initial studies revealed that the expression pattern of T1 was tightly correlated to toxin biosynthesis in the examined alga and may be used to serve as a potential toxin indicator. PMID:15800974

  6. First Detection of Tetrodotoxin in Greek Shellfish by UPLC-MS/MS Potentially Linked to the Presence of the Dinoflagellate Prorocentrum minimum

    PubMed Central

    Vlamis, Aristidis; Katikou, Panagiota; Rodriguez, Ines; Rey, Verónica; Alfonso, Amparo; Papazachariou, Angelos; Zacharaki, Thetis; Botana, Ana M.; Botana, Luis M.

    2015-01-01

    During official shellfish control for the presence of marine biotoxins in Greece in year 2012, a series of unexplained positive mouse bioassays (MBA) for lipophilic toxins with nervous symptomatology prior to mice death was observed in mussels from Vistonikos Bay–Lagos, Rodopi. This atypical toxicity coincided with (a) absence or low levels of regulated and some non-regulated toxins in mussels and (b) the simultaneous presence of the potentially toxic microalgal species Prorocentrum minimum at levels up to 1.89 × 103 cells/L in the area’s seawater. Further analyses by different MBA protocols indicated that the unknown toxin was hydrophilic, whereas UPLC-MS/MS analyses revealed the presence of tetrodotoxins (TTXs) at levels up to 222.9 μg/kg. Reviewing of official control data from previous years (2006–2012) identified a number of sample cases with atypical positive to asymptomatic negative MBAs for lipophilic toxins in different Greek production areas, coinciding with periods of P. minimum blooms. UPLC-MS/MS analysis of retained sub-samples from these cases revealed that TTXs were already present in Greek shellfish since 2006, in concentrations ranging between 61.0 and 194.7 μg/kg. To our knowledge, this is the earliest reported detection of TTXs in European bivalve shellfish, while it is also the first work to indicate a possible link between presence of the toxic dinoflagellate P. minimum in seawater and that of TTXs in bivalves. Confirmed presence of TTX, a very heat-stable toxin, in filter-feeding mollusks of the Mediterranean Sea, even at lower levels to those inducing symptomatology to humans, indicates that this emerging risk should be seriously taken into account by the EU to protect the health of shellfish consumers. PMID:26008234

  7. Assessment of the hydrolysis process for the determination of okadaic acid-group toxin ester: presence of okadaic acid 7-O-acyl-ester derivates in Spanish shellfish.

    PubMed

    Villar-Gonzlez, A; Rodrguez-Velasco, M L; Ben-Gigirey, B; Yasumoto, T; Botana, L M

    2008-04-01

    The contamination of different types of shellfish by okadaic acid (OA)-group toxin esters is an important problem that presents serious risk for human health. During previous investigations carried out in our laboratory by liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS), the occurrence of a high percentage of esters in relation to the total OA equivalents has been observed in several shellfish species. The determination of these kinds of toxins using LC/MS or other chemical methods requires a hydrolysis step in order to convert the sterified compounds into the parent toxins, OA, dinophysistoxins-1 (DTX-1) and dinophysistoxins-2 (DTX-2). Most of the hydrolysis procedures are based on an alkaline hydrolysis reaction. However, despite hydrolysis being a critical step within the analysis, it has not been studied in depth up to now. The present paper reports the results obtained after evaluating the hydrolysis process of an esterified form of OA by using a standard of 7-O-acyl ester with palmitoyl as the fatty acid (palOA). Investigations were focused on checking the effectiveness of the hydrolysis for palOA using methanol as solvent standard and matrices matched standards. From the results obtained, no matrix influence on the hydrolysis process was observed and the quantity of palOA converted into OA was always above 80%. The analyses of different Spanish shellfish samples showed percentages of palOA in relation to the total OA esters ranging from 27% to 90%, depending on the shellfish specie. PMID:18243269

  8. Evaluation of optimal conditions for determination of low selenium content in shellfish samples collected at Todos os Santos Bay, Bahia, Brazil using HG-AFS.

    PubMed

    Lopes Dos Santos, Walter Nei; Macedo, Samuel Marques; Teixeira da Rocha, Sofia Negreiros; Souza de Jesus, Caio Niela; Cavalcante, Dannuza Dias; Hatje, Vanessa

    2014-08-01

    This work proposes a procedure for the determination of total selenium content in shellfish after digestion of samples in block using cold finger system and detection using atomic fluorescent spectrometry coupled hydride generation (HG AFS). The optimal conditions for HG such as effect and volume of prereduction KBr 10% (m/v) (1.0 and 2.0ml) and concentration of hydrochloric acid (3.0 and 6.0molL(-1)) were evaluated. The best results were obtained using 3mL of HCl (6molL(-1)) and 1mL of KBr 10% (m/v), followed by 30min of prereduction for the volume of 1mL of the digested sample. The precision and accuracy were assessed by the analysis of the Certified Reference Material NIST 1566b. Under the optimized conditions, the detection and quantification limits were 6.06 and 21.21?gkg(-1), respectively. The developed method was applied to samples of shellfish (oysters, clams, and mussels) collected at Todos os Santos Bay, Bahia, Brazil. Selenium concentrations ranged from 0.23??0.02 to 3.70??0.27mgkg(-1) for Mytella guyanensis and Anomalocardia brasiliana, respectively. The developed method proved to be accurate, precise, cheap, fast, and could be used for monitoring Se in shellfish samples. PMID:24771464

  9. Simultaneous determination of 2-naphthol and 1-hydroxypyrene in fish and shellfish contaminated with crude oil by gas chromatography-mass spectrometry.

    PubMed

    Lim, Hyun-Hee; Shin, Ho-Sang

    2013-06-01

    This paper describes a gas chromatography-mass spectrometric method of l-hydroxypyrene (1-HOP) and 2-naphthol (2-NAP) in fish and shellfish. Alkali hydrolysis method in this study was chosen and optimized to the reaction condition for 90 min at 90°C in a 2.0M KOH solution. For five independent determinations at 0.2 and 1.0 μg/kg, the coefficient of variation was less than 5.1%. This method was used to assess the long-term influence of spilled crude oil on marine ecosystems and analyze fifty-two shellfish samples taken in the near of the accident region of the Hebei Spirit oil spill. 2-NAP and 1-HOP were detected in the mean concentration range of 0.09-12.42 and 0.03-0.06 μg/kg, respectively. 2-NAP was detected in a high concentration range in shellfishes gathered in 2 months after the accident and it decreased rapidly to 6 months after that. The results showed that 2-NAP might be an important biomarker in biota contaminated with crude oil. PMID:23411178

  10. Rapid liquid chromatography for paralytic shellfish toxin analysis using superficially porous chromatography with AOAC Official Method 2005.06.

    PubMed

    Hatfield, Robert G; Turner, Andrew D

    2012-01-01

    The bioaccumulation of paralytic shellfish toxins in mussels, oysters, cockles, hard clams, razors, and king scallops is monitored in England, Scotland, and Wales by AOAC Official Method 2005.06 LC-with fluorescence detection (FLD). One of the commonly perceived disadvantages of using this method is the long turnaround time and low throughput in a busy laboratory environment. The chromatographic analysis of each sample typically utilizes a 15 min cycle time to achieve toxin oxidation product separation and column equilibration prior to subsequent analysis. A standard RP C18 analytical column, used successfully in recent years, achieves good separation with a long column lifetime. The analysis of a 40 sample qualitative screening batch takes approximately 18 h, including blanks, standards, and other QC samples. The availability of superficially porous column technology has offered the potential to reduce analysis time while retaining column performance on existing hardware. In this study, AOAC Official Method 2005.06 with LC-FLD was transferred to two different commercially available superficially porous columns, and the method performance characteristics were evaluated. Both columns separated all toxins adequately with cycle times less than half that of the existing method. Linearity for each toxin was acceptable up to two times the European maximum permitted limit of 800 microg di-HCl saxitoxin equivalent/kg flesh. LOD and LOQ values were substantially improved for the majority of toxins, with gonyautoxin 1&4 and neosaxitoxin showing up to a two- and fourfold improvement, respectively, depending on the column used. Quantification results obtained from parallel analysis of contaminated samples were acceptable on both columns. Comparative screen results gave a slight increase in the occurrence of contaminated samples, which was attributed to the improved detection limit for most toxins. Issues with rapidly increasing back pressure, however, were identified with both columns, with a limit of around 500 injections. This compares to the >3000 cycles routinely obtained with the standard RP-C18 HPLC columns currently in use. Overall, the gain achieved with these columns through shorter analysis time and improved analytical sensitivity is potentially of benefit in a high-throughput environment. For the routine high-throughput screening of shellfish samples, however, an improved column lifetime is desirable. PMID:22970577

  11. Transformation of paralytic shellfish poisoning toxins in UK surf clams (Spisula solida) for targeted production of reference materials.

    PubMed

    Turner, Andrew D; Lewis, Adam M; O'Neil, Alison; Hatfield, Robert G

    2013-04-01

    The periodic occurrence of Paralytic Shellfish Poisoning (PSP) toxins in UK surf clams and the recent move away from biological assays for PSP testing resulted in the need to determine method performance characteristics for the replacement analytical method in this species. With the requirement for laboratory reference materials to aid this validation together with known issues relating to toxin transformation in live clams and homogenised tissue, there was the need to assess the toxin transformation characteristics of PSP toxins in surf clam tissue. Initial work examined the rates of toxin transformation in UK surf clam tissue incubated with toxin standards, showing rapid transformation of N-sulfocarbamoyl toxins with slower transformation of carbamate toxins. Full transformational pathways were determined using a combination of three different analytical methods and confirmed the major expected transformations involving decarbamoylation, with some evidence for additional reaction pathways. Results obtained from the analysis of surf clam and oyster tissues incubated with varying concentrations of toxic Alexandrium algae highlighted expected transformation reactions, although significant differences were observed in the extent of the transformations amongst the range of toxins studied, with less efficient transformation of N-hydroxylated toxins as compared with other carbamate and N-sulfocarbamoyl toxins. Analysis of PSP-toxic incurred oyster, scallop and mussel tissues incubated with variable proportions of surf clam tissue showed large differences in the extent of the transformations. Total conversion of N-sulfocarbamoyl toxins was confirmed at low relative proportions of surf clam tissue in all three species, whereas transformation of carbamate toxins was found to occur only in the presence of higher proportions of surf clam tissue in oysters and mussels in comparison with scallops. Results enabled the production of three laboratory reference materials prepared following incubation of incurred homogenates with optimum proportions of surf clam tissue, resulting in materials containing a large number of PSP toxins. Stability experiments provided good preliminary evidence for the stability of these targeted materials under storage conditions. The work therefore provides both additional information relating to the transformational activity in UK surf clams and highlights a good potential method for the targeted production of reference materials which include a wider range of toxins than normally present in naturally incurred shellfish. PMID:23369833

  12. Stanols as a tool to track the origin of microbial contamination of oysters, Crassostrea gigas, in shellfish areas.

    NASA Astrophysics Data System (ADS)

    Harrault, Loc; Jard, Emilie; Jeanneau, Laurent; Petitjean, Patrice

    2013-04-01

    Runoff of cattle manures (cows, pigs, sheeps) or discharge of effluent from wastewater treatment plants (WWTP) into aquatic ecosystems can lead to microbiological contamination of waters and living organisms. In coastal ecosystems and particularly in shellfish harvesting areas, the presence of pathogen microorganisms in waters induces fecal contamination of filter feeding bivalves (oysters, mussels, scallops), therefore leading to human health risks associated to the consumption of these contaminated organisms. Watershed management plans that aim at limiting these risks require the development of tools able to identify fecal contamination sources. The fecal indicator bacteria used in the regulations to determine fecal contamination are not source specific since they are found in the feces of most warm-blooded animals. Thus, microbiological biomarkers have been developed in association with chemical biomarkers as Microbial Source Tracking (MST) methods. Fecal stanols, by-products of sterols obtained by human and animal microbial gut flora, are found in considerable amounts in feces with different relative proportions depending on their animal or human source. Recently, in association with microbiological biomarkers, the stanol fingerprint of contaminated waters has been successfully used to determine the main source of fecal contamination (cow, pig or human sources) in rural watersheds (Brittany, France). Up to now, the use of the stanol fingerprint to track the fecal contamination in shellfish tissues, especially bivalves, has been limited to the analysis of coprostanol, a stanol commonly associated to human contamination. Therefore, whether the stanol fingerprint can be used as a MST method in bivalves or not is still unknown. The first aim of this study was to compare several organic extraction procedures of stanols in the oyster Crassostrea gigas to determine a reliable method for stanol fingerprint analysis in bivalves. Solvent extraction and purification steps have been carried out with attention as they are critical for stanol quantification. Secondly, the evolution of the stanol fingerprint of oysters with time was evaluated during 6 days by artificially contaminating microcosms with two concentrations of a WWTP effluent. In the microcosms, the fingerprint of stanols as a chemical biomarkers of fecal (human) contamination was compared to counts of Escherichia coli, a commonly used microbial indicator. In association with microbial markers, the method developed from the two previous steps will be applied at the watershed scale in order to identify sources of fecal contamination in Brittany and Normandy (France).

  13. Maternal fish and shellfish consumption and wheeze, eczema and food allergy at age two: a prospective cohort study in Brittany, France

    PubMed Central

    2013-01-01

    Background Environmental exposures, including dietary contaminants, may influence the developing immune system. This study assesses the association between maternal pre-parturition consumption of seafood and wheeze, eczema, and food allergy in preschool children. Fish and shellfish were studied separately as they differ according to their levels of omega-3 polyunsaturated fatty acids (which have anti-allergic properties) and their levels of contaminants. Methods The PELAGIE cohort included 3421 women recruited at the beginning of pregnancy. Maternal fish and shellfish intake was measured at inclusion by a food frequency questionnaire. Wheeze, eczema, and food allergy were evaluated by a questionnaire completed by the mother when the child was 2 years old (n = 1500). Examination of the associations between seafood intake and outcomes took major confounders into account. Complementary sensitivity analyses with multiple imputation enabled us to handle missing data, due mostly to attrition. Results Moderate maternal pre-parturition fish intake (1 to 4 times a month) was, at borderline significance, associated with a lower risk of wheeze (adjusted OR = 0.69 (0.45-1.05)) before age 2, compared with low intake (< once/month). This result was not, however, consistent: after multiple imputation, the adjusted OR was 0.86 (0.63-1.17). Shellfish intake at least once a month was associated with a higher risk of food allergy before age 2 (adjusted OR = 1.62 (1.11-2.37)) compared to low or no intake (< once/month). Multiple imputation confirmed this association (adjusted OR = 1.52 (1.05-2.21)). Conclusions This study suggests that maternal pre-parturition shellfish consumption may increase the risk of food allergy. Further large-scale epidemiologic studies are needed to corroborate these results, identify the contaminants or components of shellfish responsible for the effects observed, determine the persistence of the associations seen at age 2, and investigate potential associations with health effects observable at later ages, such as allergic asthma. PMID:24295221

  14. Persistent Contamination of Octopuses and Mussels with Lipophilic Shellfish Toxins during Spring Dinophysis Blooms in a Subtropical Estuary

    PubMed Central

    Mafra, Luiz L.; Lopes, Daiana; Bonilauri, Vanessa C.; Uchida, Hajime; Suzuki, Toshiyuki

    2015-01-01

    This study investigates the occurrence of diarrhetic shellfish toxins (DSTs) and their producing phytoplankton species in southern Brazil, as well as the potential for toxin accumulation in co-occurring mussels (Perna perna) and octopuses (Octopus vulgaris). During the spring in 2012 and 2013, cells of Dinophysis acuminata complex were always present, sometimes at relatively high abundances (max. 1143 cells L−1), likely the main source of okadaic acid (OA) in the plankton (max. 34 ng L−1). Dinophysis caudata occurred at lower cell densities in 2013 when the lipophilic toxins pectenotoxin-2 (PTX-2) and PTX-2 seco acid were detected in plankton and mussel samples. Here, we report for the first time the accumulation of DSTs in octopuses, probably linked to the consumption of contaminated bivalves. Perna perna mussels were consistently contaminated with different DSTs (max. 42 µg kg−1), and all octopuses analyzed (n = 5) accumulated OA in different organs/tissues: digestive glands (DGs) > arms > gills > kidneys > stomach + intestine. Additionally, similar concentrations of 7-O-palmytoyl OA and 7-O-palmytoly dinophysistoxin-1 (DTX-1) were frequently detected in the hepatopancreas of P. perna and DGs of O. vulgaris. Therefore, octopuses can be considered a potential vector of DSTs to both humans and top predators such as marine mammals. PMID:26096277

  15. Paralytic shellfish poisoning (PSP) toxin binders for optical biosensor technology: problems and possibilities for the future: a review

    PubMed Central

    Campbell, K.; Rawn, D.F.K.; Niedzwiadek, B.; Elliott, C.T.

    2011-01-01

    This review examines the developments in optical biosensor technology, which uses the phenomenon of surface plasmon resonance, for the detection of paralytic shellfish poisoning (PSP) toxins. Optical biosensor technology measures the competitive biomolecular interaction of a specific biological recognition element or binder with a target toxin immobilised onto a sensor chip surface against toxin in a sample. Different binders such as receptors and antibodies previously employed in functional and immunological assays have been assessed. Highlighted are the difficulties in detecting this range of low molecular weight toxins, with analogues differing at four chemical substitution sites, using a single binder. The complications that arise with the toxicity factors of each toxin relative to the parent compound, saxitoxin, for the measurement of total toxicity relative to the mouse bioassay are also considered. For antibodies, the cross-reactivity profile does not always correlate to toxic potency, but rather to the toxin structure to which it was produced. Restrictions and availability of the toxins makes alternative chemical strategies for the synthesis of protein conjugate derivatives for antibody production a difficult task. However, when two antibodies with different cross-reactivity profiles are employed, with a toxin chip surface generic to both antibodies, it was demonstrated that the cross-reactivity profile of each could be combined into a single-assay format. Difficulties with receptors for optical biosensor analysis of low molecular weight compounds are discussed, as are the potential of alternative non-antibody-based binders for future assay development in this area. PMID:21623494

  16. Immunoassay of paralytic shellfish toxins by moving magnetic particles in a stationary liquid-phase lab-on-a-chip.

    PubMed

    Kim, Myoung-Ho; Choi, Suk-Jung

    2015-04-15

    In this study, we devised a stationary liquid-phase lab-on-a-chip (SLP LOC), which was operated by moving solid-phase magnetic particles in the stationary liquid phase. The SLP LOC consisted of a sample chamber to which a sample and reactants were added, a detection chamber containing enzyme substrate solution, and a narrow channel connecting the two chambers and filled with buffer. As a model system, competitive immunoassays of saxitoxin (STX), a paralytic shellfish toxin, were conducted in the SLP LOC using protein G-coupled magnetic particles (G-MPs) as the solid phase. Anti-STX antibodies, STX-horseradish peroxidase conjugate, G-MPs, and a STX sample were added to the sample chamber and reacted by shaking. While liquids were in the stationary state, G-MPs were transported from the sample chamber to the detection chamber by moving a magnet below the LOC. After incubation to allow the enzymatic reaction to occur, the absorbance of the detection chamber solution was found to be reciprocally related to the STX concentration of the sample. Thus, the SLP LOC may represent a novel, simple format for point-of-care testing applications of enzyme-linked immunosorbent assays by eliminating complicated liquid handling steps. PMID:25460894

  17. Apoptosis of hemocytes from lions-paw scallop Nodipecten subnodosus induced with paralyzing shellfish poison from Gymnodinium catenatum.

    PubMed

    Estrada, Norma; Ascencio, Felipe; Shoshani, Liora; Contreras, Rubn G

    2014-12-01

    The toxic dinoflagellate Gymnodinium catenatum produces paralyzing shellfish poisons (PSPs) that are consumed and accumulated by bivalves. Previously, we recorded a decrease in hemocytes 24h after injection of PSPs (gonyautoxin 2/3 epimers, GTX2/3) in the adductor muscle in the lions-paw scallop Nodipecten subnodosus. In this work, qualitative and quantitative analyses, in in vivo and in vitro experiments, revealed that the lower count of hemocytes results from cells undergoing typical apoptosis when exposed to GTX 2/3 epimers. This includes visible morphological alterations of the cytoplasmic membrane, damage to the nuclear membrane, condensation of chromatin, DNA fragmentation, and release of DNA fragments into the cytoplasm. Induction of apoptosis was accompanied by phosphatidylserine exposure to the outer cell membrane and activation of cysteine-aspartic proteases, caspase 3 and caspase 8. Addition of an inhibitor of caspase to the medium suppressed activation in hemocytes exposed to the toxins, suggesting that cell death was induced by a caspase-dependent apoptotic pathway. The results are important for future investigation of the scallop's immune system and should provide new insights into apoptotic processes in immune cells of scallops exposed to PSPs. PMID:25097151

  18. Paralytic shellfish toxin content is related to genomic sxtA4 copy number in Alexandrium minutum strains.

    PubMed

    Stüken, Anke; Riobó, Pilar; Franco, José; Jakobsen, Kjetill S; Guillou, Laure; Figueroa, Rosa I

    2015-01-01

    Dinoflagellates are microscopic aquatic eukaryotes with huge genomes and an unusual cell regulation. For example, most genes are present in numerous copies and all copies seem to be obligatorily transcribed. The consequence of the gene copy number (CPN) for final protein synthesis is, however, not clear. One such gene is sxtA, the starting gene of paralytic shellfish toxin (PST) synthesis. PSTs are small neurotoxic compounds that can accumulate in the food chain and cause serious poisoning incidences when ingested. They are produced by dinoflagellates of the genera Alexandrium, Gymnodium, and Pyrodinium. Here we investigated if the genomic CPN of sxtA4 is related to PST content in Alexandrium minutum cells. SxtA4 is the 4th domain of the sxtA gene and its presence is essential for PST synthesis in dinoflagellates. We used PST and genome size measurements as well as quantitative PCR to analyze sxtA4 CPN and toxin content in 15 A. minutum strains. Our results show a strong positive correlation between the sxtA4 CPN and the total amount of PST produced in actively growing A. minutum cells. This correlation was independent of the toxin profile produced, as long as the strain contained the genomic domains sxtA1 and sxtA4. PMID:25983733

  19. Paralytic shellfish toxin content is related to genomic sxtA4 copy number in Alexandrium minutum strains

    PubMed Central

    Stüken, Anke; Riobó, Pilar; Franco, José; Jakobsen, Kjetill S.; Guillou, Laure; Figueroa, Rosa I.

    2015-01-01

    Dinoflagellates are microscopic aquatic eukaryotes with huge genomes and an unusual cell regulation. For example, most genes are present in numerous copies and all copies seem to be obligatorily transcribed. The consequence of the gene copy number (CPN) for final protein synthesis is, however, not clear. One such gene is sxtA, the starting gene of paralytic shellfish toxin (PST) synthesis. PSTs are small neurotoxic compounds that can accumulate in the food chain and cause serious poisoning incidences when ingested. They are produced by dinoflagellates of the genera Alexandrium, Gymnodium, and Pyrodinium. Here we investigated if the genomic CPN of sxtA4 is related to PST content in Alexandrium minutum cells. SxtA4 is the 4th domain of the sxtA gene and its presence is essential for PST synthesis in dinoflagellates. We used PST and genome size measurements as well as quantitative PCR to analyze sxtA4 CPN and toxin content in 15 A. minutum strains. Our results show a strong positive correlation between the sxtA4 CPN and the total amount of PST produced in actively growing A. minutum cells. This correlation was independent of the toxin profile produced, as long as the strain contained the genomic domains sxtA1 and sxtA4. PMID:25983733

  20. Persicobacter psychrovividus sp. nov., isolated from shellfish, and emended descriptions of the genus Persicobacter and Persicobacter diffluens.

    PubMed

    Muramatsu, Yuki; Takahashi, Mai; Kaneyasu, Mika; Iino, Takao; Suzuki, Ken-ichiro; Nakagawa, Yasuyoshi

    2010-08-01

    The taxonomic position of three bacterial strains, Asr22-19T, NBRC 101035 and NBRC 101041, isolated from shellfish in Japan, was determined by using a polyphasic taxonomic approach. The strains were facultatively anaerobic, motile by gliding and Gram-staining-negative slender rods. Their major respiratory quinone was menaquinone-7 and their predominant cellular fatty acids were iso-C15:0, iso-C17:0 3-OH, iso-C15:0 3-OH, C16:0 3-OH, and C16:0. The G+C content of the genomic DNA was 42.0-42.7 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that the strains clustered with the genus Persicobacter in the family 'Flammeovirgaceae'. DNA-DNA relatedness values were higher than 68% among strains Asr22-19T, NBRC 101035 and NBRC 101041, and were lower than 28% between strain Asr22-19T and Persicobacter diffluens NBRC 15940T. The three novel strains could be differentiated from Persicobacter diffluens by several phenotypic characteristics. On the basis of these results, the novel species Persicobacter psychrovividus sp. nov. (type strain Asr22-19T=NBRC 101262T=CIP 109100T) is proposed and emended descriptions are given for the genus Persicobacter and for Persicobacter diffluens. PMID:19734280

  1. Diversity of Infectious Pancreatic Necrosis Virus Strains Isolated from Fish, Shellfish, and Other Reservoirs in Northwestern Spain

    PubMed Central

    Cutrin, J. M.; Olveira, J. G.; Barja, J. L.; Dopazo, C. P.

    2000-01-01

    A comparison was done of 231 strains of birnavirus isolated from fish, shellfish, and other reservoirs in a survey study that began in 1986 in Galicia (northwestern Spain). Reference strains from all of the infectious pancreatic necrosis virus serotypes were included in the comparison, which was done by neutralization tests and agarose and polyacrylamide gel electrophoresis of the viral genome. The neutralization tests with antisera against the West Buxton, Spajarup (Sp), and Abild (Ab) strains showed that most of the Galician isolates were European types Sp and Ab; however, many isolates (30%) could not be typed. Results from agarose gels did not provided information for grouping of the strains, since all were found to have genomic segments of similar sizes. Analysis of polyacrylamide gels, however, allowed six electropherogroups (EGs) to be differentiated on the basis of genome mobility and separation among segments, and a certain relationship between EGs and serotypes was observed. A wide diversity of electropherotypes was observed among the Galician isolates, and as neutralization tests showed, most of the isolates were included in EGs corresponding to European types Ab and Sp. Only 6.5% of the isolates had the electropherotype characteristic of American strains. PMID:10653762

  2. The sxt Gene and Paralytic Shellfish Poisoning Toxins as Markers for the Monitoring of Toxic Alexandrium Species Blooms.

    PubMed

    Penna, Antonella; Perini, Federico; Dell'Aversano, Carmela; Capellacci, Samuela; Tartaglione, Luciana; Giacobbe, Maria Grazia; Casabianca, Silvia; Fraga, Santiago; Ciminiello, Patrizia; Scardi, Michele

    2015-12-15

    Paralytic shellfish poisoning (PSP) is a serious human illness caused by the ingestion of seafood contaminated with saxitoxin and its derivatives (STXs). These toxins are produced by some species of marine dinoflagellates within the genus Alexandrium. In the Mediterranean Sea, toxic Alexandrium spp. blooms, especially of A. minutum, are frequent and intense with negative impact to coastal ecosystem, aquaculture practices and other economic activities. We conducted a large scale study on the sxt gene and toxin distribution and content in toxic dinoflagellate A. minutum of the Mediterranean Sea using both quantitative PCR (qPCR) and HILIC-HRMS techniques. We developed a new qPCR assay for the estimation of the sxtA1 gene copy number in seawater samples during a bloom event in Syracuse Bay (Mediterranean Sea) with an analytical sensitivity of 2.0 × 10° sxtA1 gene copy number per reaction. The linear correlation between sxtA1 gene copy number and microalgal abundance and between the sxtA1 gene and STX content allowed us to rapidly determine the STX-producing cell concentrations of two Alexandrium species in environmental samples. In these samples, the amount of sxtA1 gene was in the range of 1.38 × 10(5) - 2.55 × 10(8) copies/L and the STX concentrations ranged from 41-201 nmol/L. This study described a potential PSP scenario in the Mediterranean Sea. PMID:26580419

  3. Persistent Contamination of Octopuses and Mussels with Lipophilic Shellfish Toxins during Spring Dinophysis Blooms in a Subtropical Estuary.

    PubMed

    Mafra, Luiz L; Lopes, Daiana; Bonilauri, Vanessa C; Uchida, Hajime; Suzuki, Toshiyuki

    2015-06-01

    This study investigates the occurrence of diarrhetic shellfish toxins (DSTs) and their producing phytoplankton species in southern Brazil, as well as the potential for toxin accumulation in co-occurring mussels (Perna perna) and octopuses (Octopus vulgaris). During the spring in 2012 and 2013, cells of Dinophysis acuminata complex were always present, sometimes at relatively high abundances (max. 1143 cells L-1), likely the main source of okadaic acid (OA) in the plankton (max. 34 ng L-1). Dinophysis caudata occurred at lower cell densities in 2013 when the lipophilic toxins pectenotoxin-2 (PTX-2) and PTX-2 seco acid were detected in plankton and mussel samples. Here, we report for the first time the accumulation of DSTs in octopuses, probably linked to the consumption of contaminated bivalves. Perna perna mussels were consistently contaminated with different DSTs (max. 42 µg kg-1), and all octopuses analyzed (n = 5) accumulated OA in different organs/tissues: digestive glands (DGs) > arms > gills > kidneys > stomach + intestine. Additionally, similar concentrations of 7-O-palmytoyl OA and 7-O-palmytoly dinophysistoxin-1 (DTX-1) were frequently detected in the hepatopancreas of P. perna and DGs of O. vulgaris. Therefore, octopuses can be considered a potential vector of DSTs to both humans and top predators such as marine mammals. PMID:26096277

  4. Future oceanic warming and acidification alter immune response and disease status in a commercial shellfish species, Mytilus edulis L.

    PubMed

    Mackenzie, Clara L; Lynch, Sharon A; Culloty, Sarah C; Malham, Shelagh K

    2014-01-01

    Increases in atmospheric carbon dioxide are leading to physical changes in marine environments including parallel decreases in ocean pH and increases in seawater temperature. This study examined the impacts of a six month exposure to combined decreased pH and increased temperature on the immune response and disease status in the blue mussel, Mytilus edulis L. Results provide the first confirmation that exposure to future acidification and warming conditions via aquarium-based simulation may have parallel implications for bivalve health. Collectively, the data suggests that temperature more than pH may be the key driver affecting immune response in M. edulis. Data also suggests that both increases in temperature and/or lowered pH conditions may lead to changes in parasite abundance and diversity, pathological conditions, and bacterial incidence in M. edulis. These results have implications for future management of shellfish under a predicted climate change scenario and future sustainability of shellfisheries. Examination of the combined effects of two stressors over an extended exposure period provides key preliminary data and thus, this work represents a unique and vital contribution to current research efforts towards a collective understanding of expected near-future impacts of climate change on marine environments. PMID:24927423

  5. Pectenotoxin-2 seco acid, 7-epi-pectenotoxin-2 seco acid and pectenotoxin-2 in shellfish and plankton from Portugal.

    PubMed

    Vale, Paulo; de M Sampayo, Maria Antónia

    2002-07-01

    Pectenotoxin-2 seco acid (PTX2sa) and 7-epi-pectenotoxin-2 seco acid (7-epi-PTX2sa) were found in Portuguese shellfish both by fluorescence detection after ADAM derivatisation and, liquid chromatography coupled with mass spectrometry detection. Two time-series both with blue mussel (Mytilus edulis) and common cockle (Cerastoderma edule) from Aveiro lagoon illustrate how PTX2sa has a strong association with Dinophysis acuta occurrence in the plankton, as well as Dinophysis fortii. Data so far excludes D. acuminata from contributing to contamination with pectenotoxins. It also shows that mussel may not be the best indicator of contamination with PTX2sa. At Aveiro lagoon also oyster, razor clam and clams were all less toxic than cockle. Pectenotoxin-2 seco acid was not involved in a previously reported incident of human poisoning that took place in February 1998 after consumption of Donax trunculus. In plankton extracts the most abundant pectenotoxin found was PTX2. Concentration of PTX2sa was around 10% of PTX2, and 7-epi-PTX2sa was not detected. PMID:12076652

  6. Paralytic shellfish toxin profiles and toxin variability of the genus Alexandrium (Dinophyceae) isolated from the Southeast China Sea.

    PubMed

    Wang, Da-Zhi; Zhang, Shu-Gang; Gu, Hai-Feng; Chan, Leo Lai; Hong, Hua-Sheng

    2006-08-01

    Paralytic shellfish toxin (PST) profiles of 16 Alexandrium isolates from the Southeast China Sea were analyzed by high-pressure liquid chromatography. Toxin content and composition of three A. tamarense isolates, ATDH01, ATGX02 and ATMJ02, were also investigated at different growth phases and under various culture conditions. Our results showed that six strains of A. affine were non-toxic, while 10 strains of A. tamarense and A. catenella were toxic. These toxic isolates grown in the same culture conditions consistently produced an unusually high proportion of the N-sulfocarbamoyl toxin C1/2 (around 60-80% of total toxins) and medium amounts of gonyautoxin GTX5 (around 15-30% of total) with only trace quantities (<5% of total) of other saxitoxin derivatives (i.e. GTX1, GTX3, GTX4 and neoSTX). The toxin composition of three A. tamarense isolates did not vary with the growth phases, although higher toxin contents (Qt, fmolcell(-1)) were found in the exponential phase. Variations in temperature, salinity and nutrient levels affected toxin content of three A. tamarense isolates but they did not have pronounced effects on the toxin composition (mole %). These results indicate that toxin composition remained relatively constant under various culture conditions, suggesting that toxin composition could be used as a stable biomarker for the Alexandrium species in this region. However, comparison of toxin profiles between isolates from different localities require special caution since isolates even from the same region can have distinct toxin profiles. PMID:16859722

  7. Analysis of paralytic shellfish toxins, potential chemical threat agents, in food using hydrophilic interaction liquid chromatography-mass spectrometry.

    PubMed

    Jansson, Daniel; Åstot, Crister

    2015-10-23

    A novel method for determining paralytic shellfish toxin (PST) profiles in food was developed using a combination of silica and strong cation exchange (SCX) solid phase extraction (SPE) coupled to hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS). Besides the risk for natural contamination of seafood and drinking water, PSTs also pose potent threats through intentional contamination of food, due to their high toxicity and the wide distributions of toxin-producing algae. The new preparation method aim to maintain the samples' original toxin profiles by avoiding conditions known to induce interconversion or degradation of the PSTs. The method was evaluated for PST extraction from water, milk, orange juice, apple purée, baby food, and blue mussels (Mytilus edulis). The extracts were found to produce reproducible retention times in HILIC-MS/MS analysis. When an authentic toxic mussel sample was analyzed using the novel method, saxitoxin and gonyautoxin-3 were identified, in agreement with data acquired using the Lawrence pre-column oxidation high-performance liquid chromatography-fluorescence detection (HPLC-FLD) method. Overall recoveries of the PSTs from tested foods by the novel method ranged from 36% to 111%. PMID:26404910

  8. Graphene based pipette tip solid phase extraction of marine toxins in shellfish muscle followed by UPLC-MS/MS analysis.

    PubMed

    Shen, Qing; Gong, Like; Baibado, Joewel T; Dong, Wei; Wang, Yixuan; Dai, Zhiyuan; Cheung, Hon-Yeung

    2013-11-15

    Graphene is a novel carbonic material with great potentials for the use as sorbent due to its ultrahigh surface area. Herein, we report the use of graphene as sorbent in solid-phase extraction (SPE) using pipette tip as cartridge namely GPT-SPE, together with ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS), for the analysis of lipophilic marine toxins (LMTs), including yessotoxins (YTX), okadaic acid (OA), dinophysistoxin-1 (DTX1), gymnodimine (GYM), spirolides-1 (SPX1), pectenotoxin-2 (PTX2) and azaspiracid-1 (AZA1) in shellfish. The GPT-SPE procedure was optimized and the performance of graphene was fully validated. Results with high-sensitivity and good reproducibility was obtained and compared with that of other sorbents like C18 silica, multi-walled carbon nanotubes (MWCNTs), commercial Oasis HLB, and Strata-X for the extraction of LMTs, which showed superiority and advantages of graphene, such as good recoveries, stability and compatibility with various solvents. In order to exhibit the potentials of graphene as an excellent sorbent material, 67 mussel samples from six coastal cities of China were analyzed. OA was found to be the dominant contaminant, while YTX was also detected with low level. PMID:24148472

  9. Exposure to the Paralytic Shellfish Toxin Producer Alexandrium catenella Increases the Susceptibility of the Oyster Crassostrea gigas to Pathogenic Vibrios.

    PubMed

    Abi-Khalil, Celina; Lopez-Joven, Carmen; Abadie, Eric; Savar, Veronique; Amzil, Zouher; Laabir, Mohamed; Rolland, Jean-Luc

    2016-01-01

    The multifactorial etiology of massive Crassostrea gigas summer mortalities results from complex interactions between oysters, opportunistic pathogens and environmental factors. In a field survey conducted in 2014 in the Mediterranean Thau Lagoon (France), we evidenced that the development of the toxic dinoflagellate Alexandrium catenella, which produces paralytic shellfish toxins (PSTs), was concomitant with the accumulation of PSTs in oyster flesh and the occurrence of C. gigas mortalities. In order to investigate the possible role of toxic algae in this complex disease, we experimentally infected C. gigas oyster juveniles with Vibrio tasmaniensis strain LGP32, a strain associated with oyster summer mortalities, after oysters were exposed to Alexandrium catenella. Exposure of oysters to A. catenella significantly increased the susceptibility of oysters to V. tasmaniensis LGP32. On the contrary, exposure to the non-toxic dinoflagellate Alexandrium tamarense or to the haptophyte Tisochrysis lutea used as a foraging alga did not increase susceptibility to V. tasmaniensis LGP32. This study shows for the first time that A. catenella increases the susceptibility of Crassostrea gigas to pathogenic vibrios. Therefore, in addition to complex environmental factors explaining the mass mortalities of bivalve mollusks, feeding on neurotoxic dinoflagellates should now be considered as an environmental factor that potentially increases the severity of oyster mortality events. PMID:26784228

  10. Future Oceanic Warming and Acidification Alter Immune Response and Disease Status in a Commercial Shellfish Species, Mytilus edulis L.

    PubMed Central

    Mackenzie, Clara L.; Lynch, Sharon A.; Culloty, Sarah C.; Malham, Shelagh K.

    2014-01-01

    Increases in atmospheric carbon dioxide are leading to physical changes in marine environments including parallel decreases in ocean pH and increases in seawater temperature. This study examined the impacts of a six month exposure to combined decreased pH and increased temperature on the immune response and disease status in the blue mussel, Mytilus edulis L. Results provide the first confirmation that exposure to future acidification and warming conditions via aquarium-based simulation may have parallel implications for bivalve health. Collectively, the data suggests that temperature more than pH may be the key driver affecting immune response in M. edulis. Data also suggests that both increases in temperature and/or lowered pH conditions may lead to changes in parasite abundance and diversity, pathological conditions, and bacterial incidence in M. edulis. These results have implications for future management of shellfish under a predicted climate change scenario and future sustainability of shellfisheries. Examination of the combined effects of two stressors over an extended exposure period provides key preliminary data and thus, this work represents a unique and vital contribution to current research efforts towards a collective understanding of expected near-future impacts of climate change on marine environments. PMID:24927423

  11. Exposure to the Paralytic Shellfish Toxin Producer Alexandrium catenella Increases the Susceptibility of the Oyster Crassostrea gigas to Pathogenic Vibrios

    PubMed Central

    Abi-Khalil, Celina; Lopez-Joven, Carmen; Abadie, Eric; Savar, Veronique; Amzil, Zouher; Laabir, Mohamed; Rolland, Jean-Luc

    2016-01-01

    The multifactorial etiology of massive Crassostrea gigas summer mortalities results from complex interactions between oysters, opportunistic pathogens and environmental factors. In a field survey conducted in 2014 in the Mediterranean Thau Lagoon (France), we evidenced that the development of the toxic dinoflagellate Alexandrium catenella, which produces paralytic shellfish toxins (PSTs), was concomitant with the accumulation of PSTs in oyster flesh and the occurrence of C. gigas mortalities. In order to investigate the possible role of toxic algae in this complex disease, we experimentally infected C. gigas oyster juveniles with Vibrio tasmaniensis strain LGP32, a strain associated with oyster summer mortalities, after oysters were exposed to Alexandrium catenella. Exposure of oysters to A. catenella significantly increased the susceptibility of oysters to V. tasmaniensis LGP32. On the contrary, exposure to the non-toxic dinoflagellate Alexandrium tamarense or to the haptophyte Tisochrysis lutea used as a foraging alga did not increase susceptibility to V. tasmaniensis LGP32. This study shows for the first time that A. catenella increases the susceptibility of Crassostrea gigas to pathogenic vibrios. Therefore, in addition to complex environmental factors explaining the mass mortalities of bivalve mollusks, feeding on neurotoxic dinoflagellates should now be considered as an environmental factor that potentially increases the severity of oyster mortality events. PMID:26784228

  12. Paralytic shellfish poisoning due to ingestion of Gymnodinium catenatum contaminated cockles--application of the AOAC HPLC official method.

    PubMed

    Rodrigues, Susana Margarida; de Carvalho, Mamede; Mestre, Tiago; Ferreira, Joaquim J; Coelho, Miguel; Peralta, Rita; Vale, Paulo

    2012-04-01

    The potent paralytic shellfish toxins (PSTs) produced by Gymnodinium catenatum have appeared irregularly since the onset in 1986 of a monitoring program aimed at preventing contaminated bivalves from the Portuguese coast to reaching the consumer. In years where high contamination levels were attained, sporadic episodes of human poisonings were also recorded, as in 1994. The reappearance of high contamination led to the appearance of new cases during 2007. This study reports details of toxin ingestion, symptomatology and toxin presence in the fluids of one of these victims, an adult male who ingested several kilograms of cockles. In cockle samples collected the week before and during the week when the intoxication took place, the major PSTs detected by the HPLC method based on AOAC Official Method 2005.06 belonged to the sulfamate (81-68molar percent) and decarbamoyl groups (19-32molar percent), comprising GTX5, GTX6, C1,2, C3,4, dcNeo, and dcSTX. In the patient urine sample sulfamate and decarbamoyl derivatives were also found, comprising by GTX5 (28%), GTX6 (25%), dcSTX (24%) and dcNeo (22%), but no C toxins and no dcGTX2,3 were detected. Compared to the cockle samples, there was an increase in the proportion of dcSTX, dcNeo and GTX5 (molar percentage) in the urine sample, but not of GTX6. Overall, compounds which had the presence of an O-sulfate at C11 were absent in urine while being relatively abundant in the bivalve (36.5-47.0 molar percent). In blood plasma PSTs were not detected. PMID:22326725

  13. Acoustic habitat and shellfish mapping and monitoring in shallow coastal water - Sidescan sonar experiences in The Netherlands

    NASA Astrophysics Data System (ADS)

    van Overmeeren, Ronnie; Craeymeersch, Johan; van Dalfsen, Jan; Fey, Frouke; van Heteren, Sytze; Meesters, Erik

    2009-11-01

    Sidescan sonar has been applied in a number of shallow water environments along the Dutch coast to map and monitor shellfish and seabed habitats. The littoral setting of these surveys may hamper data acquisition flying the towfish in zones of turbulence and waves, but also offers valuable opportunities for understanding, interpreting and validating sidescan sonar images because of the ability to ground-truth during low water periods, enabling easy identification and validation. Acoustical images of some of the mussel banks on the tidal flats of the Wadden Sea, recorded at high tide, show a marked resemblance with optical Google Earth images of the same banks. These sonar images may thus serve as ' acoustic type signatures' for the interpretation of sonar patterns recorded in deeper water where ground-truthing is more difficult and more expensive. Similarly, acoustic type signatures of (Japanese) oyster banks were obtained in the estuaries in the southwest of the Netherlands. Automated acoustic pattern recognition of different habitats and acoustical estimation of faunal cover and density are possible applications of sidescan sonar. Both require that the backscattering observed on the sidescan sonar images is directly caused by the biological component of the seafloor. Filtering offers a simple and effective pre-processing technique to separate the faunal signals from linear trends such as emanating from wave ripples or the central tracks of the towfish. Acoustically estimating the faunal density is approached by in-situ counting peaks in backscattering in unit squares. These counts must be calibrated by ground-truthing. Ground-truthing on littoral mussel banks in the Wadden Sea has been carried out by measuring their cover along lines during low tide. Due to its capacity of yielding full-cover, high resolution images of large surfaces, sidescan sonar proves to be an excellent, cost-effective tool for quantitative time-lapse monitoring of habitats.

  14. Amnesic shellfish poisoning biotoxin detection in seawater using pure or amino-functionalized Ag nanoparticles and SERS.

    PubMed

    Mller, Csilla; Glamuzina, Branko; Pozniak, Iva; Weber, Karina; Cialla, Dana; Popp, Jrgen; Cnt? Pnzaru, Simona

    2014-12-01

    Domoic acid (DA) biotoxin responsible for the amnesic shellfish poisoning (ASP) has been unambiguously detected in seawater in a broad range of concentration, with both pure and amino-functionalized Ag nanoparticles employed for surface enhanced Raman scattering (SERS). To achieve this, a comprehensive SERS study on DA dissolved in distilled water has been conducted. SERS of DA dissolved in seawater in concentrations ranging from 3.3 10(-4) to 3.3 10(-8) mol l(-1) exhibited specific signal, completely different to those of the corresponding DA aqueous solutions, due to the seawater interference in the overall SERS effect. In order to assess the capability of the technique as a cheaper alternative for rapid and unambiguous detection of the DA biotoxin in seawater, three detection schemes have been proposed. DA was detectable at 0.33 nmoll(-1) concentration (0.33) dissolved in distilled water and 0.033 nmol l(-1) (0.033 ppb) in seawater respectively, much lower than the admitted level by the current regulation. A solvent specific interaction of DA with the NPs was concluded, since DA aqueous solution added to Ag nanoparticles provided different SERS signal compared to that of DA directly dissolved in seawater. Employing amino-functionalized Ag nanoparticles with 4-aminothiophenol as SERS tag, SERS signal of DA on amino-AgNPs revealed significant specificity associated with the aromatic primary amine interaction of the SERS tag with DA, thus allowing DA detection in seawater at 4.16 10(-4) mol l(-1) concentration, much higher than in the case of pure NPs. To highlight the findings, a brief literature review to date on the DA biotoxin detection was also provided. PMID:25159386

  15. Influence of Different Shellfish Matrices on the Separation of PSP Toxins Using a Postcolumn Oxidation Liquid Chromatography Method

    PubMed Central

    Rey, Verónica; Alfonso, Amparo; Botana, Luis M.; Botana, Ana M.

    2015-01-01

    The separation of PSP toxins using liquid chromatography with a post-column oxidation fluorescence detection method was performed with different matrices. The separation of PSP toxins depends on several factors, and it is crucial to take into account the presence of interfering matrix peaks to produce a good separation. The matrix peaks are not always the same, which is a significant issue when it comes to producing good, reliable results regarding resolution and toxicity information. Different real shellfish matrices (mussel, scallop, clam and oyster) were studied, and it was seen that the interference is not the same for each individual matrix. It also depends on the species, sampling location and the date of collection. It was proposed that separation should be accomplished taking into account the type of matrix, as well as the concentration of heptane sulfonate in both solvents, since the mobile phase varies regarding the matrix. Scallop and oyster matrices needed a decrease in the concentration of heptane sulfonate to separate GTX4 from matrix peaks, as well as dcGTX3 for oysters, with a concentration of 6.5 mM for solvent A and 6.25 mM for solvent B. For mussel and clam matrices, interfering peaks are not as large as they are in the other group, and the heptane sulfonate concentration was 8.25 mM for both solvents. Also, for scallops and oysters, matrix interferences depend not only on the sampling site but also on the date of collection as well as the species; for mussels and clams, differences are noted only when the sampling site varies. PMID:25884908

  16. Accumulation trends of petroleum hydrocarbons in commercial shellfish from the Galician coast (NW Spain) affected by the Prestige oil spill.

    PubMed

    Viñas, L; Franco, M A; Soriano, J A; González, J J; Ortiz, L; Bayona, J M; Albaigés, J

    2009-04-01

    Aliphatic and aromatic hydrocarbons were determined in three species of commercial shellfish, namely razor shells (Ensis arcuatus and Ensis siliqua), goose barnacle (Pollicipes cornucopia) and sea urchin (Paracentrotus lividus), living in different habitats and exhibiting different feeding behaviors. The samples were collected monthly, from January 2003 to October 2004, in three stations of the Galicia coast (NW Spain), following the Prestige oil spill, with the aim of assessing their response to the spill and, therefore, their suitability for monitoring purposes. The aliphatic fractions were mostly dominated by biogenic hydrocarbons, reflecting the diet composition of the organisms and their low metabolic capacity. The presence of oil was assessed by the determination of chemical markers. The analysis of the aromatic fractions revealed the occurrence of 3-6 ring parent and alkylated PAHs, consistent with a mixed petrogenic-pyrolytic origin, with the common feature of the predominance of chrysene in all samples collected after the spill. However, the distributions exhibited both temporal and interspecies variations. The PAH concentrations (Sigma13) increased significantly after the spill and decreased 6-7 months later close to background levels for the region. One year after the accident, the median values were: 58 microg/kg for razor shells, 26 microg/kg for barnacles, and 25 microg/kg for sea urchins. The temporal evolution of the PAH concentrations along the survey period was used to estimate loss rates for bioavailable PAHs in barnacles and sea urchins after the spill. Half-life values were in the order of 30 and 60 d, respectively. The results of the study demonstrate that barnacles can be suitable species for oil spill monitoring. PMID:19150729

  17. Analysis of paralytic shellfish toxins using high-field asymmetric waveform ion mobility spectrometry with liquid chromatography-mass spectrometry.

    PubMed

    Beach, Daniel G; Melanson, Jeremy E; Purves, Randy W

    2015-03-01

    The analysis of paralytic shellfish toxins (PSTs) by liquid chromatography-mass spectrometry remains a challenge because of their high polarity, large number of analogues and the complex matrix in which they occur. Here we investigate the potential utility of high-field asymmetric waveform ion mobility spectrometry (FAIMS) as a gas-phase ion separation tool for analysis of PSTs by mass spectrometry. We investigate the separation of PSTs using FAIMS with two divergent goals: using FAIMS as a primary separation tool for rapid screening by electrospray ionization (ESI)-FAIMS-MS or combined with LC in a multidimensional LC-ESI-FAIMS-MS separation. First, a survey of the parameters that affect the sensitivity and selectivity of PST analysis by FAIMS was carried out using ESI-FAIMS-MS. In particular, the use of acetonitrile as a gas additive in the carrier gas flow offered good separation of all PST epimeric pairs. A second set of FAIMS conditions was also identified, which focussed PSTs to a relatively narrow CV range allowing development of an LC-ESI-FAIMS-MS method for analysis of PST toxins in complex mussel tissue extracts. The quantitative capabilities of this method were evaluated by analysing a PST containing mussel tissue matrix material. Results compared favourably with analysis by an established LC-post-column oxidation-fluorescence method with recoveries ranging from 70 to 106%, although sensitivity was somewhat reduced. The current work represents the first successful separation of PST isomers using ion mobility and shows the promise of FAIMS as a tool for analysis of algal biotoxins in complex samples and outlines some critical requirements for its future improvement. PMID:25619987

  18. Carcinogen adducts as an indicator for the public health risks of consuming carcinogen-exposed fish and shellfish

    SciTech Connect

    Dunn, B.P. )

    1991-01-01

    A large variety of environmental carcinogens are metabolically activated to electrophilic metabolites that can bind to nucleic acids and protein, forming covalent adducts. The formation of DNA-carcinogen adducts is thought to be a necessary step in the action of most carcinogens. Recently, a variety of new fluorescence, immunochemical, and radioactive-postlabeling procedures have been developed that allow the sensitive measurement of DNA-carcinogen adducts in organisms exposed to environmental carcinogens. In some cases, similar procedures have been developed for protein-carcinogen adducts. In an organism with active metabolic systems for a given carcinogen, adducts are generally much longer lived than the carcinogens that formed them. Thus, the detection of DNA- or protein-carcinogen adducts in aquatic foodstuffs can act as an indicator of prior carcinogen exposure. The presence of DNA adducts would, in addition, suggest a mutagenic/carcinogenic risk to the aquatic organism itself. Vertebrate fish are characterized by high levels of carcinogen metabolism, low body burdens of carcinogen, the formation of carcinogen-macromolecule adducts, and the occurrence of pollution-related tumors. Shellfish, on the other hand, have low levels of carcinogen metabolism, high body burdens of carcinogen, and have little or no evidence of carcinogen-macromolecule adducts or tumors. The consumption of carcinogen adducts in aquatic foodstuffs is unlikely to represent a human health hazard. There are no metabolic pathways by which protein-carcinogen or DNA-carcinogen adducts could reform carcinogens. Incorporation via salvage pathways of preformed nucleoside-carcinogen adducts from foodstuffs into newly synthesized human DNA is theoretically possible.

  19. Evaluation of variability and quality control procedures for a receptor-binding assay for paralytic shellfish poisoning toxins.

    PubMed

    Ruberu, S R; Langlois, G W; Masuda, M; Perera, S Kusum

    2012-01-01

    The receptor-binding assay (RBA) method for determining saxatoxin (STX) and its numerous analogues, which cause paralytic shellfish poisoning (PSP) in humans, was evaluated in a single laboratory study. Each step of the assay preparation procedure including the performance of the multi-detector TopCount instrument was evaluated for its contribution to method variability. The overall inherent RBA variability was determined to be 17%. Variability within the 12 detectors was observed; however, there was no reproducible pattern in detector performance. This observed variability among detectors could be attributed to other factors, such as pipetting errors. In an attempt to reduce the number of plates rejected due to excessive variability in the method's quality control parameters, a statistical approach was evaluated using either Grubbs' test or the Student's t-test for rejecting outliers in the measurement of triplicate wells. This approach improved the ratio of accepted versus rejected plates, saving cost and time for rerunning the assay. However, the potential reduction in accuracy and the lack of improvement in precision suggests caution when using this approach. The current study has recommended an alternate quality control procedure for accepting or rejecting plates in place of the criteria currently used in the published assay, or the alternative of outlier testing. The recommended procedure involves the development of control charts to monitor the critical parameters identified in the published method (QC sample, EC??, slope of calibration curve), with the addition of a fourth critical parameter which is the top value (100% binding) of the calibration curve. PMID:22928711

  20. Seasonal dynamics of trophic relationships among co-occurring suspension-feeders in two shellfish culture dominated ecosystems

    NASA Astrophysics Data System (ADS)

    Lefebvre, Sébastien; Marín Leal, Julio César; Dubois, Stanislas; Orvain, Francis; Blin, Jean-Louis; Bataillé, Marie-Paule; Ourry, Alain; Galois, Robert

    2009-04-01

    The temporal dynamics of carbon and nitrogen isotope values of co-occurring suspension-feeders in two shellfish culture areas (Normandy, France) were investigated over two years to evaluate the inter-specific trophic partitioning and relative contributions of organic matter sources to benthic suspension-feeders' diet. Oysters ( Crassostrea gigas), mussels ( Mytilus edulis), cockles ( Cerastoderma edule), slipper limpets ( Crepidula fornicata), and sand-mason worms ( Lanice conchilega) were sampled in an estuarine environment (Baie des Veys, east Cotentin, Normandy), while oysters, mussels, slipper limpets, and honeycomb worms ( Sabellaria alveolata) were sampled in an open-marine environment (Lingreville-sur-mer, west Cotentin, Normandy). Whatever the sampling period, the bivalves, C. gigas and M. edulis, exhibited the lowest values of δ13C and δ15N compared with the other species. Feeding relationships among suspension-feeders in both C. gigas culture areas exhibited temporal variations due to the marine/estuarine influence and seasonal changes in food supply. In the open-marine ecosystem, the contribution of phytoplankton remained the most important for all species except S. alveolata, while in the estuarine ecosystem, microphytobenthos and/or macroalgae detritus contributed a larger extent to the organisms' diets. During phytoplankton bloom periods (e.g. May and July) suspension-feeders, except for S. alveolata, relied strongly on phytoplankton; however, the majority of suspension-feeders exhibited different opportunistic behaviour in winter when phytoplankton biomass might be a limiting factor. We hypothesized that differences in particle capture and selection by the suspension-feeders influenced their isotopic values. Feeding ecology of suspension-feeders partly explained why competition was limited and why ecosystems can often support unexpectedly large numbers of suspension-feeders. We also showed that understanding ecosystem characteristics of the organic matter sources is of primary importance to determine the extent to which members of the suspension-feeding guild potentially compete for food.

  1. Assessment of a semiquantitative liquid chromatography-fluorescence detection method for the determination of paralytic shellfish poisoning toxin levels in bivalve molluscs from Great Britain.

    PubMed

    Turner, Andrew D; Dhanji-Rapkova, Monika; Baker, Clothilde; Algoet, Myriam

    2014-01-01

    AOAC Official Method 2005.06 precolumn oxidation LC-fluorescence detection method has been used for many years for the detection and quantitation of paralytic shellfish poisoning (PSP) toxins in bivalve molluscs. After extensive single- and multiple-laboratory validation, the method has been slowly gaining acceptance worldwide as a useful and practical tool for official control testing. In Great Britain, the method has become routine since 2008, with no requirement since then for reverting back to the bioassay reference method. Although the method has been refined to be semiautomated, faster, and more reproducible, the quantitation step can be complex and time-consuming. An alternative approach was developed to utilize the qualitative screening results for generating a semiquantitative results assessment. Data obtained over 5 years enabled the comparison of semiquantitative and fully quantitative PSP results in over 15 000 shellfish samples comprising eight different species showed that the semiquantitative approach resulted in over-estimated paralytic shellfish toxin levels by an average factor close to two in comparison with the fully quantified levels. No temporal trends were observed in the data or relating to species type, with the exception of surf clams. The comparison suggested a semiquantitative threshold of 800 microg saxitoxin (STX) eq/kg should provide a safe limit for the determination of samples to be forwarded to full quantitation. However, the decision was taken to halve this limit to include an additional safety factor of 2, resulting in the use of a semiquantitative threshold of 400 microg STX eq/kg. Implementation of the semiquantitative method into routine testing would result in a significant reduction in the numbers of samples requiring quantitation and have a positive impact on the overall turnaround of reported PSP results. The refined method would be appropriate for any monitoring laboratory faced with high throughput requirements. PMID:24830161

  2. Association between fish and shellfish, and omega-3 PUFAs intake and CVD risk factors in middle-aged female patients with type 2 diabetes

    PubMed Central

    Kim, Hyesook; Park, Seokyung; Yang, Hyesu; Choi, Young Ju; Huh, Kap Bum

    2015-01-01

    BACKGROUND/OBJECTIVES This study was performed to investigate the association between the dietary intake of fish and shellfish, and omega-3 polyunsaturated fatty acids (PUFAs) and cardiovascular disease (CVD) risk factors in the middle-aged Korean female patients with Type 2 diabetes (T2D). SUBJECTS/METHODS A cross-sectional analysis was performed with 356 female patients (means age: 55.5 years), who were recruited from the Huh's Diabetes Clinic in Seoul, Korea between 2005 and 2011. The dietary intake was assessed by a validated semi-quantitative food frequency questionnaire and analyzed using the Computer Aided Nutritional Analysis program (CAN-Pro) version 4.0 software. RESULTS In a multiple regression analysis after the adjustment for confounding factors such as age, BMI, duration of diagnosed T2D, alcohol consumption, fiber intake, sodium intake, and total energy intake, fish and shellfish intake of the subjects was negatively associated with triglyceride and pulse wave velocity (PWV). Omega-3 PUFAs intake was negatively associated with triglyceride, systolic blood pressures, diastolic blood pressures, and PWV. The multiple logistic regression analysis with the covariates showed a significant inverse relationship between the omega-3 PUFAs consumption and prevalence of hypertriglyceridemia [OR (95% CI) for greater than the median compared to less than the median: 0.395 (0.207-0.753)]. CONCLUSIONS These results suggest that the consumption of fish and shellfish, good sources of omega-3 PUFAs, may reduce the risk factors for CVD in the middle-aged female patients with T2D. PMID:26425279

  3. Confirmation of brevetoxin metabolism in cockle, Austrovenus stutchburyi, and greenshell mussel, Perna canaliculus, associated with New Zealand neurotoxic shellfish poisoning, by controlled exposure to Karenia brevis culture.

    PubMed

    Ishida, Hitoshi; Nozawa, Akira; Nukaya, Haruo; Rhodes, Lesley; McNabb, Paul; Holland, Patrick T; Tsuji, Kuniro

    2004-05-01

    We examined metabolism of PbTxs in New Zealand cockle, Austrovenus (A.) stutchburyi, and greenshell mussel, Perna (P.) canaliculus, by means of liquid chromatography coupled with tandem mass spectrometry. PbTx-2, PbTx-3 and BTX-B5 were detected in Karenia (K.) brevis culture medium in the ratio of ca. 50:2:5. The amounts of PbTx-3 and BTX-B5 were greatly increased in both seawater and shellfish exposed to K. brevis cultures or supernatant prepared by disruption of K. brevis under appropriate condition, while those of PbTx-2 were decreased. Some PbTx-2 was present in P. canaliculus, but not in A. stutchburyi. Low levels of BTX-B1 were detected in A. stutchburyi, but not P. canaliculus. Levels of PbTx-3 and BTX-B5 were highest immediately after exposure and then declined rapidly in both shellfish. BTX-B1 increased in concentration after exposure, and was then gradually eliminated from A. stutchburyi. Three successive exposures of A. stutchburyi to K. brevis cultures resulted in similar initial levels of PbTx-3 and BTX-B5, while BTX-B1 accumulated after each dose. In P. canaliculus, initial levels of PbTx-3 were similar, while PbTx-2 and BTX-B5 accumulated after each dose. PbTx-3 and BTX-B5 are proposed to be suitable markers for monitoring shellfish toxicity after a red tide event. PMID:15109891

  4. Systematic detection of BMAA (β-N-methylamino-l-alanine) and DAB (2,4-diaminobutyric acid) in mollusks collected in shellfish production areas along the French coasts.

    PubMed

    Réveillon, Damien; Séchet, Véronique; Hess, Philipp; Amzil, Zouher

    2016-02-01

    The neurotoxin β-N-methylamino-l-alanine (BMAA) is naturally present in some microalgal species in the marine environment. The accumulation of BMAA has widely been observed in filter-feeding bivalves that are known to consume primary producers constituting the base of complex aquatic food webs. This study was performed to assess the occurrence of BMAA and isomers in mollusks collected from nine representative shellfish production areas located on the three French coasts (Channel, Atlantic and Mediterranean sites). The use of a highly selective and sensitive HILIC-MS/MS method, with D5DAB as internal standard, revealed the systematic detection of BMAA and DAB, in concentrations ranging from 0.20 to 6.7 μg g(-1) dry weight of digestive gland tissues of mollusks. While we detected BMAA in four strains of diatoms in a previous study, here BMAA was only detected in one diatom species previously not investigated out of the 23 microalgal species examined (belonging to seven classes). The concentrations of BMAA and DAB in mussels and oysters were similar at different sampling locations and despite the high diversity of phytoplankton populations that mollusks feed on at these locations. Only small variations of BMAA and DAB levels were observed and these were not correlated to any of the phytoplankton species reported. Therefore, extensive research should be performed on both origin and metabolism of BMAA in shellfish. The levels observed in this study are similar to those found in other studies in France or elsewhere. A previous study had related such levels to a cluster of Amyotrophic Lateral Sclerosis in the South of France; hence the widespread occurrence of BMAA in shellfish from all coasts in France found in this study suggests the need for further epidemiological and toxicological studies to establish the levels that are relevant for a link between the consumption of BMAA-containing foodstuffs and neurodegenerative diseases. PMID:26615827

  5. Development and validation of the first high performance-lateral flow immunoassay (HP-LFIA) for the rapid screening of domoic acid from shellfish extracts.

    PubMed

    Jawaid, Waqass; Meneely, Julie; Campbell, Katrina; Hooper, Mark; Melville, Karrie; Holmes, Stephen; Rice, Jennifer; Elliott, Christopher

    2013-11-15

    A lateral flow immunoassay (LFIA) has been developed and fully validated to detect the primary amnesic shellfish poisoning (ASP) toxin, domoic acid (DA). The performance characteristics of two versions of the test were investigated using spiked and naturally contaminated shellfish (mussels, scallops, oysters, clams, and cockles). The tests provide a qualitative result, to indicate the absence or presence of DA in extracts of shellfish tissues, at concentrations that are relevant to regulatory limits. The new rapid assay (LFIA version 2) was designed to overcome the performance limitations identified in the first version of the assay. The improved test uses an electronic reader to remove the subjective nature of the generated results, and the positive cut-off for screening of DA in shellfish was increased from 10 ppm (version 1) to 17.5 ppm (version 2). A simple extraction and test procedure was employed, which required minimal equipment and materials; results were available 15 min after sample preparation. Stability of the aqueous extracts at room temperature (22 C) at four time points (up to 245 min after extraction) and across a range of DA concentrations was 100.31.3% and 98.82.4% for pre- and post-buffered extracts, respectively. The assay can be used both within laboratory settings and in remote locations. The accuracy of the new assay, to indicate negative results at or below 10 ppm DA, and positive results at or above 17.5 ppm, was 99.5% (n=216 tests). Validation data were obtained from a 2-day, randomised, blind study consisting of multiple LFIA lots (n=3), readers (n=3) and operators (n=3), carrying out multiple extractions of mussel tissue (n=3) at each concentration (0, 10, 17.5, and 20 ppm). No matrix effects were observed on the performance of the assay with different species (mussels, scallops, oysters, clams, and cockles). There was no impact on accuracy or interference from other phycotoxins, glutamic acid or glutamine with various strip incubations (8, 10, and 12 min). The accuracy of the assay, using naturally contaminated samples to indicate negative results at or below 12.5 ppm and positive results at or above 17.5 ppm, was 100%. Variability between three LFIA lots across a range of DA concentrations, expressed as coefficient of variation (% CV), was 1.10.4% (n=2 days) based on quantitative readings from the electronic reader. During an 8 week stability study, accuracy of the method with test strips stored at various temperatures (6, 22, 37 and 50 C) was 100%. Validation for both versions included comparisons with results obtained using reference LC-UV methods. PMID:24148459

  6. A tyrosine-containing analog of mu-conotoxin GIIIA as ligand in the receptor binding assay for paralytic shellfish poisons.

    PubMed

    Mendoza, Aileen D L; Sombrito, Elvira Z; Cruz, Lourdes J

    2015-06-01

    Development of novel analytical tools to detect marine biotoxins has been warranted in view of the apparent global pervasiveness of algal-derived shellfish poisoning, and the limitations of existing methods. Here, we describe the initial phase in the development and evaluation of a tyrosine-containing analog of ?-conotoxin (?-CTX) GIIIA as an alternative to saxitoxin (STX) in a receptor binding assay (RBA) for paralytic shellfish poisons. The peptide analog was synthesized and characterized for structure and bioactivity. The major product of oxidation elicited paralytic symptoms in mice at a minimum dose of 1.31 mg kg(-1) (i.p.). Mass spectrometry analysis of the bioactive peptide gave a molecular mass of 2637.52 Da that was close to the predicted value. Iodination via chloramine-T produced non-, mono- and di-iodinated peptides (respectively, NIP, MIP and DIP). Competition assays against (3)H-STX revealed higher Ki and EC50 (P < 0.0001, ANOVA) indicating reduced affinity for the receptor, and limited displacement of receptor-bound STX. However, subsequent use of MIP may extend the application of RBA to detect small changes in toxin levels owing to its likely enhanced displacement by STX. This may be useful in analyzing samples with toxicities near the regulatory limit, or in establishing baseline values in high risk environments. PMID:25817004

  7. Liquid chromatography/mass spectrometry of domoic acid and lipophilic shellfish toxins with selected reaction monitoring and optional confirmation by library searching of product ion spectra.

    PubMed

    McCarron, Pearse; Wright, Elliott; Quilliam, Michael A

    2014-01-01

    LC/MS methodology for the analysis of domoic acid and lipophilic toxins in shellfish was developed using a hybrid triple quadrupole linear ion trap mass spectrometer. For routine quantitation a scheduled selected reaction monitoring (SRM) method for the analysis of domoic acid, okadaic acid, dinophysistoxins, azaspiracids, pectenotoxins, yessotoxins, gymnodimines, spirolides, and pinnatoxins was developed and validated. The method performed well in terms of LOD, linearity, precision, and trueness. Taking advantage of the high instrument sensitivity, matrix effects were mitigated by reducing the amount of sample introduced to the mass spectrometer. Optionally, samples can be analyzed using information dependent acquisition (IDA) methods, either in positive or negative mode, which can provide an extra level of confirmation by matching the full product ion spectra acquired for a sample with those from a specially constructed spectral library. Methods were applied to the analysis df a new certified reference material and Canadian mussels (Mytilus edulis) implicated in a 2011 diarrhetic shellfish poisoning (DSP) incident. The scheduled SRM method enabled the screening and quantitation of multiple phycotoxins. As DSP had not previously been observed in this area of Canada, positive identification of putative toxins was accomplished using the IDA and spectral search method. Analysis of the 2011 toxic mussel samples revealed the presence of high levels of dinophysistoxin-1, which explained the DSP symptoms, as well as pectenotoxins, yessotoxins, and variety of cyclic imines. PMID:24830142

  8. Single-laboratory validation study of rapid analysis method for multi-class veterinary drugs in milk, fish and shellfish by LC-MS/MS.

    PubMed

    Nakajima, Takayuki; Nagano, Chieko; Kanda, Maki; Hayashi, Hiroshi; Hashimoto, Tsuneo; Kanai, Setsuko; Matsushima, Yoko; Tateishi, Yukinari; Sasamoto, Takeo; Takano, Ichiro

    2013-01-01

    A method of rapid analysis of multi-class residual veterinary drugs in milk, fish and shellfish was validated in accordance with Japanese guidelines for the validation of analytical methods for residual agricultural chemicals in food. Using LC-MS/MS, 43 multi-class veterinary drugs, including sulfonamides, quinolones, coccidiostats and antiparasites, could be analyzed in one injection. Analytes were extracted from samples with two kinds of solvent, acetonitrile containing 1 vol% formic acid and anhydrous acetonitrile, and salted out with 4.0 g of magnesium sulfate, 1.5 g of trisodium citrate and 2.0 g of sodium chloride. This method was assessed by performing recovery tests in retail milk and 4 kinds of fresh cultured fish and shellfish (salmon, tiger shrimp, red sea bream and bastard halibut) spiked with the 43 target analytes at the levels of 10 and 100 ?g/kg. Using this method, 40 out of 43 drugs satisfied the guideline criteria in milk, 37 drugs in salmon, 42 drugs in tiger shrimp, 41 drugs in red sea bream and 39 drugs in bastard halibut. PMID:24025214

  9. Report on the development of the FAO/INFOODS user database for fish and shellfish (uFiSh) - Challenges and possible solutions.

    PubMed

    Rittenschober, Doris; Stadlmayr, Barbara; Nowak, Verena; Du, Juan; Charrondiere, U Ruth

    2016-02-15

    Reliable food composition data are required for virtually all nutrition-related programs and policies. In many food composition tables, fish are included to a limited extent. Therefore, FAO/INFOODS decided to compile and publish a user databases for fish and shellfish (uFiSh), considering the following main objectives: to develop a global database for fish, crustaceans and molluscs with raw, cooked and processed foods; to base the database preferable on analytical data; to include major as well as minor species consumed; and to capture intra-species variation due to habitat, edible part, season or region. The development of the uFiSh is based on FAO/INFOODS international standards and guidelines. The paper describes challenges and possible solution of data compilation specific to fish and shellfish, as well as the uFiSh in terms of its structure, including coverage of nutrients, documentation and format of publication. The first edition is intended to be published in 2015. PMID:26433296

  10. Changes of paralytic shellfish toxins in gills and digestive glands of the cockle Cerastoderma edule under post-bloom natural conditions.

    PubMed

    Costa, Sara T; Vale, Carlos; Raimundo, Joana; Matias, Domitília; Botelho, Maria João

    2016-04-01

    Concentrations of the paralytic shellfish toxins C1+2, C3+4, GTX5, GTX6, dcGTX2+3, dcSTX, dcNEO, GTX2+3, GTX1+4, STX and NEO were determined by LC-FLD in composite samples of digestive glands and gills of Cerastoderma edule cockle. The specimens were sampled in Aveiro lagoon, Portugal, under natural depuration conditions (days 0, 8, 12, 14, 19, 21 and 25) after exposure to a bloom of Gymnodinium catenatum. Individual paralytic shellfish toxins indicated different pathways of elimination and biotransformation in digestive gland and gills. Toxin concentrations in gills were lower than in digestive gland. Most of the quantified toxins in digestive gland decreased during the 25 days of observation according to negative exponential curves, and only GTX5, GTX6 and NEO showed slight irregularities with time. Concentrations of C1+2, C3+4 and dcGTX2+3 in gills decreased progressively, however GTX5, GTX6 and dcSTX showed pronounced increases. Higher concentrations of those toxins in days 8 and 12 in comparison to the initial value (day 0) indicate conversion of other toxins into GTX5, GTX6 and dcSTX during those periods. It appears that inter-conversion of toxins occurs as G. catenatum cells are retained in gills before being transferred to other compartments. PMID:26874623

  11. Development and Validation of a Lateral Flow Immunoassay for the Rapid Screening of Okadaic Acid and All Dinophysis Toxins from Shellfish Extracts.

    PubMed

    Jawaid, Waqass; Meneely, Julie P; Campbell, Katrina; Melville, Karrie; Holmes, Stephen J; Rice, Jennifer; Elliott, Christopher T

    2015-09-30

    A single-step lateral flow immunoassay was developed and validated to detect okadaic acid (OA) and dinophysis toxins (DTXs), which cause diarrhetic shellfish poisoning. The performance characteristics of the test were investigated, in comparison to reference methods (liquid chromatography tandem mass spectrometry and/or bioassay), using both spiked and naturally contaminated shellfish. A portable reader was used to generate a qualitative result, indicating the absence or presence of OA-group toxins, at concentrations relevant to the maximum permitted level (MPL). Sample homogenates could be screened in 20 min (including extraction and assay time) for the presence of free toxins (OA, DTX1, DTX2). DTX3 detection could be included with the addition of a hydrolysis procedure. No matrix effects were observed from the species evaluated (mussels, scallops, oysters, and clams). Results from naturally contaminated samples (n = 72) indicated no false compliant results and no false noncompliant results at <50% MPL. Thus, the development of a new low-cost but highly effective tool for monitoring a range of important phycotoxins has been demonstrated. PMID:26287989

  12. Radioactive contamination of fish, shellfish, and waterfowl exposed to Hanford effluents: Annual summaries, 1945--1972. Hanford Environmental Dose Reconstruction Project

    SciTech Connect

    Hanf, R.W.; Dirkes, R.L.; Duncan, J.P.

    1992-07-01

    The objective of the Hanford Environmental Dose Reconstruction Project (HEDR) is to estimate the potential radiation doses received by people living within the sphere of influence of the Hanford Site. A potential critical pathway for human radiation exposure is through the consumption of waterfowl that frequent onsite waste-water ponds or through eating of fish, shellfish, and waterfowl that reside in/on the Columbia River and its tributaries downstream of the reactors. This document summarizes information on fish, shellfish, and waterfowl radiation contamination for samples collected by Hanford monitoring personnel and offsite agencies for the period 1945 to 1972. Specific information includes the types of organisms sampled, the kinds of tissues and organs analyzed, the sampling locations, and the radionuclides reported. Some tissue concentrations are also included. We anticipate that these yearly summaries will be helpful to individuals and organizations interested in evaluating aquatic pathway information for locations impacted by Hanford operations and will be useful for planning the direction of future HEDR studies.

  13. Brominated and chlorinated dioxins, PCBs and brominated flame retardants in Scottish shellfish: methodology, occurrence and human dietary exposure.

    PubMed

    Fernandes, Alwyn; Dicks, Pamela; Mortimer, David; Gem, Martin; Smith, Frankie; Driffield, Malcolm; White, Shaun; Rose, Martin

    2008-02-01

    The most commonly consumed shellfish species produced in Scotland - mussels, oysters and scallops - were investigated for the occurrence of a range of brominated and chlorinated contaminants in order to establish current levels and estimate human dietary exposure. Flesh from individual sub-samples was representatively pooled and 35 composites were analysed for brominated and chlorinated dioxins (PBDD/Fs, PCDD/Fs), brominated and chlorinated biphenyls (PBBs, PCBs), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs) and tetrabromobisphenol A (TBBPA). The analytical methodology used (13)C(12) labelled surrogates of the target compounds, with GC coupled to (usually) high resolution MS, and LC-MS/MS for HBCD and TBBPA analysis. Positive identifications were made in the majority of samples for most analytes with the exception of TBBPA and most PBDD congeners measured. None of the levels detected for PCDD/F and PCB were above the maximum permitted levels specified in European Union regulations. The levels of brominated furans predominated over brominated dioxins, reflecting the environmental distribution and source emission profiles of these contaminants, and relatively high levels of the tri-brominated congeners were observed. Levels of the flame retardant chemicals reflected current and legacy use, with appreciable concentrations of PBDEs and HBCDs (predominantly alpha-HBCD) but far lower levels of PBBs. TBBPA was not detected in any of the species. In general, mussels and oysters displayed relatively higher levels of contamination than scallops, although the gonad tissue of the latter showed significant levels of brominated dioxins. The estimated adult dietary intakes of PCDD/Fs and PCBs arising from the consumption of a typical portion of these foods in combination with an otherwise average UK diet were in the range 0.5-0.6 pg World Health Organisation (WHO)-toxic equivalent (TEQ)(2005)/kg bodyweight per day. These estimated dietary intakes are well within the Tolerable Daily Intake for dioxins and dioxin-like PCBs of 2 pg WHO-TEQ(2005)/kg bodyweight/day endorsed by the independent expert Committee on Toxicology of Chemicals in Food, Consumer Products and the Environment. The corresponding intakes for sumPBDEs and sumHBCDs were 5.6-6.1 and 5.9-7.9 ng/kg bodyweight/day respectively. PMID:18186102

  14. Buying, Preparing, and Cooking Shellfish. Learning Activity Pack and Instructor's Guide 5.13c. Commercial Foods and Culinary Arts Competency-Based Series. Section 5: Basic Food Preparation.

    ERIC Educational Resources Information Center

    Florida State Univ., Tallahassee. Center for Studies in Vocational Education.

    This document consists of a learning activity packet (LAP) for the student and an instructor's guide for the teacher. The LAP is intended to acquaint occupational home economics students with the various market forms of shellfish and how to clean, prepare, and cook them. Illustrated information sheets and learning activities are provided in these

  15. Introduction to Fish and Shellfish. Learning Activity Pack and Instructor's Guide 5.13a. Commercial Foods and Culinary Arts Competency-Based Series. Section 5: Basic Food Preparation.

    ERIC Educational Resources Information Center

    Florida State Univ., Tallahassee. Center for Studies in Vocational Education.

    This document consists of a learning activity packet (LAP) for the student and an instructor's guide for the teacher. The LAP is intended to acquaint occupational home economics students with fish and shellfish for restaurant use. Illustrated information sheets and learning activities are provided in these areas: buying and storing fish and

  16. Buying, Preparing, and Cooking Shellfish. Learning Activity Pack and Instructor's Guide 5.13c. Commercial Foods and Culinary Arts Competency-Based Series. Section 5: Basic Food Preparation.

    ERIC Educational Resources Information Center

    Florida State Univ., Tallahassee. Center for Studies in Vocational Education.

    This document consists of a learning activity packet (LAP) for the student and an instructor's guide for the teacher. The LAP is intended to acquaint occupational home economics students with the various market forms of shellfish and how to clean, prepare, and cook them. Illustrated information sheets and learning activities are provided in these…

  17. Poisoning - fish and shellfish

    MedlinePLUS

    ... contaminated waters. Scombroid poisoning usually occurs from large, dark meat fish such as tuna, mackerel, mahi mahi, and albacore. Because this poison develops after a fish is caught and dies, it does not matter where the fish is caught. The main factor ...

  18. Investigations into matrix components affecting the performance of the official bioassay reference method for quantitation of paralytic shellfish poisoning toxins in oysters.

    PubMed

    Turner, Andrew D; Dhanji-Rapkova, Monika; Algoet, Myriam; Suarez-Isla, Benjamin A; Cordova, Marco; Caceres, Catherine; Murphy, Cory J; Casey, Melanie; Lees, David N

    2012-02-01

    Significant differences previously observed in the determination of paralytic shellfish poisoning toxins (PSTs) in oysters using official method AOAC 2005.06 and 959.08 were investigated in detail with regard to possible matrix effects. Method AOAC 2005.06 gave results 2-3 times higher than the mouse bioassay method, 959.08, differences thought to be due to underestimation of PSTs by the mouse bioassay. In order to prove the cause of these large differences, work was conducted here to examine the presence and effects of matrix components on the performance of each of the two assays. A range of oyster, cockle and mussel samples were extracted using the AOAC 959.08 hydrochloric acid (HCl) extraction method and analysed for PSP by both MBA and LC-FLD. In addition, extracts were analysed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) for metals as well as being subjected to a range of nutritional testing methods. Whilst there was no evidence for effect of nutritional components on either assay, ICP-MS analysis revealed a relationship between samples exhibiting the largest differences in relative method performance, specifically those with the largest LC-FLD/MBA toxicity ratio, and samples containing the highest concentrations of zinc and manganese. In order to prove the potential effect of the metals on either the LC-FLD and/or MBA assays, HCl extracts of a range of shellfish were subjected to a number of matrix modifications. Firstly, a number of PSP-positive oyster samples were processed to reduce the concentrations of metals within the extracts, without significantly reducing the concentrations of PSTs. Secondly, a range of mussel and cockle extracts, plus a standard solution of saxitoxin di-hydrochloride were spiked at variable concentrations of zinc. All treated and non-treated extracts, plus a number of controls were subjected to ICP-MS, LC-FLD and MBA testing. Results proved the absence of any effect of metals on the performance of the LC-FLD, whilst showing a large suppressive effect of the metals on the MBA. As such, the results show the performance of the official MBA is potentially unsafe for application to the routine monitoring of PSP toxicity in oysters or in any other shellfish found to contain high concentrations of metal ions. PMID:22138287

  19. Liquid chromatography post-column oxidation (PCOX) method for the determination of paralytic shellfish toxins in mussels, clams, oysters, and scallops: collaborative study.

    PubMed

    van de Riet, Jeffrey; Gibbs, Ryan S; Muggah, Patricia M; Rourke, Wade A; MacNeil, James D; Quilliam, Michael A

    2011-01-01

    Sixteen laboratories participated in a collaborative study to evaluate method performance parameters of a liquid chromatographic method of analysis for paralytic shellfish toxins (PST) in blue mussels (Mytilus edulis), soft shell clams (Mya arenaria), sea scallops (Placopectin magellanicus), and American oysters (Crassostrea virginicus). The specific analogs tested included saxitoxin, neosaxitoxin, gonyautoxins-1 to -5, decarbamoyl-gonyautoxins-2 and -3, decarbamoyl-saxitoxin, and N-sulfocarbamoyl-gonyautoxin-2 and -3. This instrumental technique has been developed as a replacement for the current AOAC biological method (AOAC Official Method 959.08) and an alternative to the pre-column oxidation LC method (AOAC Official Method 2005.06). The method is based on reversed-phase liquid chromatography with post-column oxidation and fluorescence detection (excitation 330 nm and emission 390 nm). The shellfish samples used in the study were prepared from the edible tissues of clams, mussels, oysters, and scallops to contain concentrations of PST representative of low, medium, and high toxicities and with varying profiles of individual toxins. These concentrations are approximately equivalent to 1/2 maximum level (ML), ML, or 2xML established by regulatory authorities (0.40, 0.80, and 1.60 mg STX diHCl eq/kg, respectively). Recovery for the individual toxins ranged from 104 to 127%, and recovery of total toxin averaged 116%. Horwitz Ratio (HorRat) values for individual toxins in the materials included in the study were generally within the desired range of 0.3 to 2.0. For the estimation of total toxicity in the test materials, the reproducibility relative standard deviation ranged from 4.6 to 20%. A bridging study comparing the results from the study participants using the post-column oxidation (PCOX) method with the results obtained in the study director's laboratory on the same test materials using the accepted reference method, the mouse bioassay (MBA; AOAC Official Method 959.08), showed that the average ratio of results obtained from the two methods was 1.0. A good match of values was also achieved with a new certified reference material. The results from this study demonstrated that the PCOX method is a suitable method of analysis for PST in shellfish tissue and provides both an estimate of total toxicity, equivalent to that determined using the MBAAOAC Official Method 959.08, and a detailed profile of the individual toxin present in the sample. PMID:21919349

  20. Inorganic carbon dynamics in the upwelling system off the Oregon coast and implications for commercial shellfish hatcheries

    NASA Astrophysics Data System (ADS)

    Vance, J. M.; Hales, B. R.

    2010-12-01

    The increasing absorption of anthropogenic CO2 by the global ocean and concomitant decrease in pH will alter seawater carbonate chemistry in ways that may negatively impact calcifying organisms. In particular, the change in saturation state (Ω) of calcium carbonate minerals calcite and aragonite may be energetically unfavorable for shell formation while favoring shell dissolution. Eastern boundary upwelling systems may provide insights into how ecosystems respond to future conditions of ocean acidification when deep water with high dissolved inorganic carbon (DIC), low pH and low Ω is forced toward the surface. Mortality in commercial seed stock and reduced wild set of the oyster Crassostrea gigas in the northeast Pacific during 2005-2009 reinforced the need for understanding biological responses to acidified ocean water. In response, a long-term strategy to understand local carbonate chemistry dynamics, seasonal perturbations and the effects on development of calcifying bivalves was developed. At present, a time-series of pCO2 measurements was implemented in April 2010 in Netarts Bay, Oregon at Whiskey Creek Shellfish Hatchery (WCH). The intake sits at a depth of 0.5-8ft and water is pumped in at 100gpm. A line taken off the intake is run continuously through a thermosalinograph at approximately 1.5gpm into a showerhead style equilibrator in which the headspace is recirculated by aerating the water for enhanced gas exchange. CO2 in equilibrated air is analyzed by NDIR. Additionally two discrete samples of intake seawater were taken across tidal cycles weekly and analyzed for total CO2 (TCO2) according to the methods of Hales et al. (2004) and pCO2 for quality control. The pCO2 in the bay exhibits a diurnal cycle representative of daytime photosynthesis and nighttime respiration. However, the phasing and profiles of these cycles are dominated by tidal mixing and are affected by the introduction of high pCO2 water during upwelling events. Diurnal pCO2 during periods of low wind stress ranges from 100-700µatm. When strong equatorward winds induce upwelling, pCO2 levels exhibit a higher daily range of 300-2000µatm. The saturation state was calculated from the pCO2/TCO2 measurements of the discrete samples. The Ω for calcite and aragonite ranged from 2.07 and 1.15 to 8.58 and 4.69 respectively from April through August. Increased pCO2 and decreased pH have been shown to negatively impact larval development in C. gigas (Kurihara, 2007). Periods of elevated pCO2 in May and June 2010 correlated with commercial losses at WCH. The use of precise pCO2 measurements in real time has proven to be a valuable tool for use in aquaculture. As a commercial practice WCH has elected to only use source water that is below empirical pCO2 thresholds for spawning and culturing larvae. This has resulted in continued production and cost saving in an industry crucial to coast economies. A continuous TCO2/pCO2 monitoring system will be integrated into this long time-series to constrain inorganic carbon providing insight into carbonate chemistry dynamics in Netarts Bay, effects of ocean acidification on bivalve development and possible water treatment approaches for commercial aquaculture.

  1. Strategies for the elimination of matrix effects in the liquid chromatography tandem mass spectrometry analysis of the lipophilic toxins okadaic acid and azaspiracid-1 in molluscan shellfish.

    PubMed

    Kilcoyne, Jane; Fux, Elie

    2010-11-01

    Considerable efforts are being made worldwide to replace in vivo assays with instrumental methods of analysis for the monitoring of marine biotoxins in shellfish. Analysis of these compounds by the preferred technique of liquid chromatography tandem mass spectrometry (LC-MS/MS) is challenged by matrix effects associated with the shellfish tissues. In methods validation, assessment of matrix interferences is imperative to ensure the validity and accuracy of results being produced. Matrix interferences for the analysis of okadaic acid (OA) and azaspiracid 1 (AZA1) were assessed using acidic methods on electrospray triple stage quadrupole (TSQ) and hybrid quadrupole time of flight (QToF) instruments by the use of matrix matched standards for different tissue types. Using an acidic method no matrix interference and suppression was observed on the TSQ for OA and AZA1 respectively, whilst the opposite was observed on the QToF; matrix enhancement for OA and no matrix interference for AZA1. The suppression of AZAs on the TSQ was found to be due to interfering compounds being carried over from previous injections. The degree of suppression is very much dependant on the tissue type ranging from 15 to 70%. Several strategies were evaluated to eliminate these interferences, including the partitioning of the extract with hexane, optimisation of the chromatographic method and the use of on-line SPE. Hexane clean up did not have any impact on matrix effects. The use of an alkaline method and a modified acidic method eliminated matrix suppression for AZA1 on the TSQ instrument while an on-line SPE method proved to be effective for matrix enhancement of OA on the QToF. PMID:20926091

  2. [Can solar/geomagnetic activity restrict the occurrence of some shellfish poisoning outbreaks? The example of PSP caused by Gymnodinium catenatum at the Atlantic Portuguese coast].

    PubMed

    Vale, P

    2013-01-01

    Cyclic outbreaks of accumulation of paralytic shellfish poisoning (PSP) toxins in mussels attributed to Gymnodinium catenatum blooms displayed several of the highest inter-annual maxima coincidental with minima of the 11-year solar sunspot number (SSN) cycle. The monthly distribution of PSP was associated with low levels of the solar radio flux, a more quantitative approach than SSN for fluctuations in solar activity. A comparison between monthly distribution of PSP and other common biotoxins (okadaic acid (OA), dinophysistoxin-2 (DTX2) and amnesic shellfish poisoning (ASP) toxins) demonstrated that only PSP was significantly associated with low levels of radio flux (p < 0.01). PSP occurrence suggests a prior decline in solar activity could be required to act as a trigger, in a similar manner to a photoperiodic signal. The seasonal frequency increased towards autumn during the study period, which might be related to the progressive atmospheric cut-off of deleterious radiation associated with the seasonal change in solar declination, and might play an additional role in seasonal signal-triggering. PSP distribution was also associated with low levels of the geomagnetic index Aa. A comparison between monthly distribution of PSP and other common biotoxins, also demonstrated that only PSP was significantly associated with low levels of the Aa index (p < 0.01). In some years of SSN minima no significant PSP-outbreaks in mussels were detected. This was attributed to a steady rise in geomagnetic activity that could disrupt the triggering signal. Global distribution patterns show that hotspots for G. catenatum blooms are regions with deficient crustal magnetic anomalies. In addition to the variable magnetic field mostly of solar origin, static fields related to magnetized rocks in the crust and upper mantle might play a role in restricting worldwide geographic distribution. PMID:24455892

  3. Liquid chromatographic post-column oxidation method for analysis of paralytic shellfish toxins in mussels, clams, scallops, and oysters: single-laboratory validation.

    PubMed

    Van de Riet, Jeffrey M; Gibbs, Ryan S; Chou, Faith W; Muggah, Patricia M; Rourke, Wade A; Burns, Garth; Thomas, Krista; Quilliam, Michael A

    2009-01-01

    A single-laboratory validation study was conducted for the LC post-column oxidation analysis of paralytic shellfish toxins (PST): saxitoxin (STX); neosaxitoxin (NEO); gonyautoxins (GTX) 1-5; decarbamoyl gonyautoxins (dcGTX) 2 and 3; decarbamoyl saxitoxin (dcSTX); and N-sulfocarbamoyl-gonyautoxin-2 and 3 (C1 and C2) in mussels (Mytilus edulis), soft shell clams (Mya arenaria), scallops (Placopectin magellanicus), and oysters (Crassostrea virginicus). The instrumental technique was developed for the analysis of PST in shellfish as an alternative to the precolumn oxidation method, AOAC Official Method 2005.06, and a replacement for the current AOAC biological method 959.08. The method used reversed-phase LC with post-column oxidation and fluorescence detection. Test materials for method recovery were prepared by fortification of blank material with a cocktail of PST. Materials used to determine method repeatability and intermediate precision were prepared by blending blank material with naturally incurred material. The target total toxicity levels evaluated in the study were 0.40, 0.80, and 1.60 mg STX x diHCl equivalents per kilogram [(eq/kg) 1%, 1, and 2 times the regulatory limit]. Linearity, recovery, and within-laboratory precision parameters of the method were evaluated. Correlation coefficients of the calibration curves for all toxins studied were > 0.99. Total toxin recovery ranged from 94 to 106% at the three levels of interest. Repeatability and intermediate precision RSD ranged from 2 to 7% and 2 to 8%, respectively. The method LOD and LOQ (assuming the presence of all toxins) were determined to be equivalent to 0.18 and 0.39 mg STX x diHCl eq/kg. The method is intended for a regulatory framework and will be submitted for an AOAC collaborative study. PMID:20166587

  4. Effect of UV light on the inactivation of recombinant human adenovirus and murine norovirus seeded in seawater in shellfish depuration tanks.

    PubMed

    Garcia, Lucas A T; Nascimento, Mariana A; Barardi, Clia R M

    2015-03-01

    Shellfish depuration is a process that aims to eliminate pathogens from mollusk tissues. Seawater disinfection during the depuration process is important and ultraviolet (UV) light treatment is the most used method worldwide. Viral models are usually employed as surrogates of fastidious viruses in viability studies. The aim of this study was to employ methods based on green fluorescent protein (GFP) fluorescence and plaque forming units to detect, respectively, recombinant adenovirus (rAdV-GFP) and murine norovirus (MNV) artificially seeded in environmental matrices. These assays were applied to assess the inactivation of rAdV-GFP and MNV in seawater in recirculation shellfish depuration tanks with and without UV light treatment. Kinetics of rAdV GFP-expression was previously measured by UV-spectrophotometer. Flow cytometry (FC), fluorescence microscopy (FM), and plaque assay were used to determine virus titer and detection limits. The influence of the environmental matrix on the performance of the methods was prior determined using either drinking water or filtered seawater seeded with rAdV-GFP. Disinfection of seeded seawater was evaluated with and without UV treatment. The time of 24-h post-infection was established as ideal for fluorescence detection on rAdV-GFP infected cells. FC showed lower sensitivity, when compared to FM, which was similar to plaque assay. Seawater disinfection on depuration tanks was promising and rAdV-GFP declined 99.99 % after 24 and 48 h with and without UV treatment, respectively. MNV was completely inactivated after 24 h in both treatments. As conclusion, the depuration tanks were effective to inactivate rAdV-GFP and MNV and the UV disinfection treatment accelerated the process. PMID:25528135

  5. COMPARISON OF GENKENSIA DEMISSA (DILLWYN) POPULATIONS IN RHODE ISLAND FRINGE MARSHES WITH VARYING NITROGEN LOADS

    EPA Science Inventory

    Increased residential development in coastal watersheds has led to increases in anthropogenic nitrogen inputs into estuaries. Sessile bivalves are good candidate organisms to examine animal condition in nutrient-enriched areas because they contribute significantly to energy flow...

  6. Collaborative study for the detection of toxic compounds in shellfish extracts using cell-based assays. Part I: screening strategy and pre-validation study with lipophilic marine toxins.

    PubMed

    Srandour, Anne-Laure; Ledreux, Aurlie; Morin, Bndicte; Derick, Sylvain; Augier, Elie; Lanceleur, Rachelle; Hamlaoui, Sahima; Moukha, Serge; Furger, Christophe; Bir, Ronel; Krys, Sophie; Fessard, Valrie; Troussellier, Marc; Bernard, Ccile

    2012-06-01

    Human poisoning due to consumption of seafood contaminated with phycotoxins is a worldwide problem, and routine monitoring programs have been implemented in various countries to protect human consumers. Following successive episodes of unexplained shellfish toxicity since 2005 in the Arcachon Bay on the French Atlantic coast, a national research program was set up to investigate these atypical toxic events. Part of this program was devoted to fit-for-purpose cell-based assays (CBA) as complementary tools to collect toxicity data on atypical positive-mouse bioassay shellfish extracts. A collaborative study involving five laboratories was conducted. The responses of human hepatic (HepG2), human intestinal (Caco2), and mouse neuronal (Neuro2a) cell lines exposed to three known lipophilic phycotoxins-okadaic acid (OA), azaspiracid-1 (AZA1), and pectenotoxin-2 (PTX2)-were investigated. A screening strategy composed of standard operating procedures and a decision tree for dose-response modeling and assay validation were designed after a round of "trial-and-error" process. For each toxin, the shape of the concentration-response curves and the IC(50) values were determined on the three cell lines. Whereas OA induced a similar response irrespective of the cell line (complete sigmoid), PTX2 was shown to be less toxic. AZA1 induced cytotoxicity only on HepG2 and Neuro2a, but not on Caco2. Intra- and inter-laboratory coefficients of variation of cell responses were large, with mean values ranging from 35 to 54 % and from 37 to 48 %, respectively. Investigating the responses of the selected cell lines to well-known toxins is the first step supporting the use of CBA among the panel of methods for characterizing atypical shellfish toxicity. Considering these successful results, the CBA strategy will be further applied to extracts of negative, spiked, and naturally contaminated shellfish tissues. PMID:22538779

  7. Performance Characteristics of AOAC Method 2005.06 for the Determination of Paralytic Shellfish Toxins in Manila Clams, European Otter Clams, Grooved Carpet Shell Clams, Surf Clams, and Processed King Scallops.

    PubMed

    O'Neill, Alison; Turner, Andrew D

    2015-01-01

    An approach was developed for the verification of method performance of the AOAC 2005.06 LC-fluorescence detector (FLD) method for determination of paralytic shellfish poisoning (PSP) toxins in bivalve shellfish. This was developed following advice published by the Analytical Laboratory Accreditation Criteria Committee and applied to shellfish species that had not been previously subjected to a full single-laboratory validation scheme. The refined approach was developed following the need to assess performance in a number of shellfish species infrequently monitored through the UK statutory monitoring program, while reducing the impact and cost of the studies, most notably in terms of the use of valuable reference standards. The species assessed were manila clams (Ruditapes philippinarum), European otter clams (Lutraria lutraria), grooved carpet shell clams (R. decussatus), surf clams (Spisula solida), and king scallops (Pecten maximus) presented as adductor only or adductor plus roe. The method was assessed for sensitivity in terms of LOD and LOQ, toxin recovery, and method precision in each species. It incorporated the PSP toxins deemed toxic and/or prevalent in UK samples and commercially available as certified reference standards. The toxins studied included GTX1-5, dcSTX, STX, C1&2, and NEO. The toxins dcGTX2&3 were included for surf clams due to the prevalence of these toxins in this species as a result of toxin decarbamoylation. Method performance targets were met for each of the characteristics investigated. Consequently, the method was deemed fit for purpose for the screening and quantification of these clam and scallop species for PSP toxins by AOAC Method 2005.06 LC-FLD. PMID:26024751

  8. Winter-summer nutrient composition linkage to algae-produced toxins in shellfish at a eutrophic coastal lagoon (bidos lagoon, Portugal)

    NASA Astrophysics Data System (ADS)

    Pereira, Patrcia; Botelho, Maria Joo; Cabrita, Maria Teresa; Vale, Carlos; Moita, Maria Teresa; Gonalves, Clia

    2012-10-01

    The current work examines the linkage of pronounced winter-summer fluctuations on the nutrient composition with phytoplankton assemblages and mussel toxicity produced by the presence of toxic dinoflagellates. The work was performed at the bidos lagoon, a coastal eutrophic ecosystem that is permanently connected to an area characterized by frequent upwelling episodes. The lagoon and adjoining coastal area exhibit recurrent incidents of diarrhetic and paralytic shellfish poisoning. The conclusions are based on: (1) inorganic and organic nutrients at five sites of the lower, middle and upper bidos lagoon, and inorganic nutrients at two sites of the adjacent coastal area; biannual campaigns were performed in winter and summer between 2006 and 2010; (2) phytoplankton assemblages at three sites of the lagoon (located at lower and upper areas) in winter and summer of 2009; (3) algae-derived toxicity of wild mussels from the lower lagoon and coastal area, on a 1-2 week time scale, over 2006 and 2009. Nutrient molar ratios in bidos lagoon contrast between winter and summer. The lower median ratios DIN:P (31 and 0.8) and Si:P (11 and 3.3) in summer reflect the excess of phosphate. Excess was mainly attributed to phosphorus regeneration in sediments of the upper lagoon with accentuated symptoms of eutrophication. Dissolved organic nitrogen and dissolved organic phosphorus were also higher in summer, particularly in this area. No significant winter-summer differences were recorded for nutrient ratios in the adjacent coastal area. Phytoplankton assemblages pointed to a winter-summer contrast characterized by a shift of non-siliceous-based phytoplankton to diatoms. The toxic dinoflagellate species (Gymnodinium catenatum, Dinophysis cf. acuminata and Dinophysis acuta), presumably imported from the adjacent coast following upwelling episodes in summer, were observed in the lower lagoon. In summer of the two surveyed years, toxins produced by dinoflagellates occurred in mussels from the lower lagoon and coastal area. However, mussel toxicity in the lagoon exceeded values of the coastal area suggesting that high cell density of toxic dinoflagellates resulted from favourable nutrient conditions. We conclude that connectivity between eutrophic lagoons and upwelling systems stimulates the increase of toxic algae and consequently enhancing shellfish toxicity.

  9. Histopathological survey of potential biomarkers for the assessment of contaminant related biological effects in species of fish and shellfish collected from Kuwait Bay, Arabian Gulf.

    PubMed

    Stentiford, G D; Massoud, M S; Al-Mudhhi, S; Al-Sarawi, M A; Al-Enezi, M; Lyons, B P

    2014-07-01

    The marine environment in Kuwait is dominated by Kuwait Bay, a shallow, depositional habitat vital for the breeding and propagation of marine organisms. The bay receives effluent inputs from industrial centres, ports, sewage outflows along with discharges from power and desalination plants. The major classes of pollutant discharged into the bay include petroleum hydrocarbons, metals, nutrients, cooling water and hyper-saline water. Further, the bay has been historically impacted by a deliberate release of oil and contamination with ordnance and shipwrecks during the 1991 Gulf war. With an aim to establish an integrated pollution effects monitoring programme in Kuwait, this paper describes the application of a quality assured approach to conduct a histopathology baseline survey in oriental sole (Synaptura orientalis) and the large-toothed flounder (Pseudorhombus arsius), which are two potential sentinel flatfish species present in the Arabian Gulf. Liver and gonadal histopathology revealed a range of pathologies similar to those previously observed in European and American pollution effects surveys that utilise flatfish (including pathology markers indicative of possible carcinogenesis and endocrine disruption). Further, we extended these studies to invertebrates (Jinga prawn, Metapenaeus affinis and the grooved tiger prawn, Penaeus semisulcatus) found within the Arabian Gulf. Such baseline data is essential before attempts are made to develop integrated monitoring programmes that aim to assess the health of fish and shellfish in relation to chemical contamination. PMID:24680107

  10. Accumulation of paralytic shellfish toxins by surfclams, Spisula solidissima (Dillwyn, 1897) in the Gulf of Maine: seasonal changes, distribution between tissues, and notes on feeding habits.

    PubMed

    Shumway, S E; Sherman, S A; Cembella, A D; Selvin, R

    1994-01-01

    Accumulation of paralytic shellfish poisoning (PSP) toxins by surfclams, Spisula solidissima, was studied over a period of two years at two inshore locations in southern Maine and at six stations on Georges Bank in the Gulf of Maine. Whole animals as well as individual tissues (siphon, mantle, digestive gland, foot, adductor muscle, gill) were analyzed for PSP-toxicity levels using the standard AOAC mouse bioassay. Analyses of gut contents were carried out on surfclams from both inshore and offshore locations to identify the type of particles ingested. Surfclams feed primarily on phytoplankton and detrital material characteristic of the overlying seawater and surface sediment. No evidence was found for any selection based on particle size or type. Elevated levels of PSP toxins were noted in surfclams from Georges Bank more than two years after initial toxification. Toxins were not evenly distributed among the various tissues of surfclams. Initially, maximum toxicity among surfclam tissues was found in digestive glands; however, subsequent analyses of samples collected later in the year indicated that toxicity in gill and mantle tissues had increased relative to initial values. No toxicity was detected in adductor muscles. Surfclams are characterized by a high variation in total toxin load among individual animals, with a tendency for decreasing variation as toxin levels increase. Archived data from the Main Department of Marine Resources revealed annual and seasonal patterns of toxin accumulation by surfclams, i.e., toxin accumulation is an annual event, with initial increases in toxicity usually occurring in early spring. PMID:7952949

  11. Evaluation of toxicity equivalent factors of paralytic shellfish poisoning toxins in seven human sodium channels types by an automated high throughput electrophysiology system.

    PubMed

    Alonso, Eva; Alfonso, Amparo; Vieytes, Mercedes R; Botana, Luis M

    2016-02-01

    Although voltage-gated sodium channels (Na v ) are the cellular target of paralytic shellfish poisoning (PSP) toxins and that patch clamp electrophysiology is the most effective way of studying direct interaction of molecules with these channels, nowadays, this technique is still reduced to more specific analysis due to the difficulties of transforming it in a reliable throughput system. Actual functional methods for PSP detection are based in binding assays using receptors but not functional Na v channels. Currently, the availability of automated patch clamp platforms and also of stably transfected cell lines with human Na v channels allow us to introduce this specific and selective method for fast screenings in marine toxin detection. Taking advantage of the accessibility to pure PSP standards, we calculated the toxicity equivalent factors (TEFs) for nine PSP analogs obtaining reliable TEFs in human targets to fulfill the deficiencies of the official analytic methods and to verify automated patch clamp technology as a fast and reliable screening method for marine toxins that interact with the sodium channel. The main observation of this work was the large variation of TEFs depending on the channel subtype selected, being remarkable the variation of potency in the 1.7 channel subtype and the suitability of Na v 1.6 and 1.2 channels for PSP screening. PMID:25572188

  12. A Feedback Mechanism to Control Apoptosis Occurs in the Digestive Gland of the Oyster Crassostrea gigas Exposed to the Paralytic Shellfish Toxins Producer Alexandrium catenella

    PubMed Central

    Rolland, Jean-Luc; Medhioub, Walid; Vergnes, Agnes; Abi-khalil, Celina; Savar, Véronique; Abadie, Eric; Masseret, Estelle; Amzil, Zouher; Laabir, Mohamed

    2014-01-01

    To better understand the effect of Paralytic Shellfish Toxins (PSTs) accumulation in the digestive gland of the Pacific oyster, Crassostrea gigas, we experimentally exposed individual oysters for 48 h to a PSTs producer, the dinoflagellate Alexandrium catenella. In comparison to the effect of the non-toxic Alexandrium tamarense, on the eight apoptotic related genes tested, Bax and BI.1 were significantly upregulated in oysters exposed 48 h to A. catenella. Among the five detoxification related genes tested, the expression of cytochrome P450 (CYP1A) was shown to be correlated with toxin concentration in the digestive gland of oysters exposed to the toxic dinoflagellate. Beside this, we observed a significant increase in ROS production, a decrease in caspase-3/7 activity and normal percentage of apoptotic cells in this tissue. Taken together, these results suggest a feedback mechanism, which may occur in the digestive gland where BI.1 could play a key role in preventing the induction of apoptosis by PSTs. Moreover, the expression of CYP1A, Bax and BI.1 were found to be significantly correlated to the occurrence of natural toxic events, suggesting that the expression of these genes together could be used as biomarker to assess the biological responses of oysters to stress caused by PSTs. PMID:25257788

  13. [Analysis of the source, potential biological toxicity of heavy metals in the surface sediments from shellfish culture mudflats of Rudong Country, Jiangsu Province].

    PubMed

    Li, Lei; Wang, Yun-long; Jiang, Mei; Yuan, Qi; Shen, Xin-qiang

    2012-08-01

    Concentrations of six heavy metals were measured in the surface sediments from shellfish culture mudflats of Rudong Country, Jiangsu Province in 2010. The geo-accumulation index (Igeo) was employed to evaluate the pollution level of heavy metals and the results showed that the heavy metal contamination could be divided into three groups: no contamination (Igeo), as in the case of Cu, Cd, Hg; light to moderate contamination (0 < Igeo, < 1), as in the case of Pb, As; and moderate contamination (1 < Igeo, < 2), as in the case of Zn. The pollution level of heavy metals followed the order of Zn > As > Pb > Cd > Cu > Hg. The potential biological toxicity was analyzed using sediment quality guidelines (SQG), as the guideline values, Cd showed no potential biological toxicity, As showed occasional potential biological toxicity in all sampling stations, Cu, Pb, Zn, Hg showed potential biological toxicity in some sampling stations, whereas Zn was the only one showing frequent potential biological toxicity in some sampling stations. Sigma TUs revealed that only one of the sampling stations showed significant acute toxicity, whereas the others showed no acute toxicity. Analysis of heavy metal contamination source through principal component analysis (PCA) revealed that the contribution rates of the top two principal components were 37.56% and 33.71%, respectively, indicating that the two main sources of heavy metals were industrial waste water and pollution from transportation and shipping. PMID:23213880

  14. Paralytic shellfish toxins in the chocolata clam, Megapitaria squalida (Bivalvia: Veneridae), in Bahía de La Paz, Gulf of California.

    PubMed

    Gárate-Lizárraga, I; Bustillos-Guzmán, J J; Erler, K; Muñetón-Gómez, M S; Luckas, B; Tripp-Quezada, A

    2004-09-01

    Occurrence and toxic profiles of paralytic shellfish toxins (PST) in the chocolata clam Megapitaria squalida were investigated. From December 2001 to December 2002, 25 clams were obtained monthly from Bahia de La Paz, Gulf of California. Additionally, net (20 microm) and bottle phytoplankton samples were also collected to identify toxic species. Toxins were analyzed by HPLC with post-column oxidation and fluorescence detection. Toxicity in the clam was low and varied from 0.14 to 5.46 microg/STXeq/100 g. Toxicity was detected in December, March, April, June, and August. Toxin profile was composed mainly by STX, GTX2, GTX3, dcGTX2, dcGTX3, C2, dcSTX and B1. Gymnodinium catenatum was the only PST-producing dinoflagellate identified in the phytoplankton samples throughout the study period. G. catenatum was observed mainly in net samples from December 2001 to December 2002; however, in bottle samples, G. catenatum was only observed in five months. Highest abundance (2600 cells l(-1)) was observed in March and the lowest (160 cells l(-1)) in June. G. catenatum mainly formed two-cell chains and rarely four or eight. The presence of PST in net phytoplankton samples support the fact that G. catenatum is the main source of PST in the clams. This study represents the first report of PST toxins in the chocolata clam from Bahia de La Paz. PMID:17465127

  15. First evidence of "paralytic shellfish toxins" and cylindrospermopsin in a Mexican freshwater system, Lago Catemaco, and apparent bioaccumulation of the toxins in "tegogolo" snails (Pomacea patula catemacensis).

    PubMed

    Berry, John P; Lind, Owen

    2010-05-01

    Exposure to cyanobacterial toxins in freshwater systems, including both direct (e.g., drinking water) and indirect (e.g., bioaccumulation in food webs) routes, is emerging as a potentially significant threat to human health. We investigated cyanobacterial toxins, specifically cylindrospermopsin (CYN), the microcystins (MCYST) and the "paralytic shellfish toxins" (PST), in Lago Catemaco (Veracruz, Mexico). Lago Catemaco is a tropical lake dominated by Cylindrospermopsis, specifically identified as Cylindrospermopsis catemaco and Cylindrospermopsis philippinensis, and characterized by an abundant, endemic species of snail (Pomacea patula catemacensis), known as "tegogolos," that is both consumed locally and commercially important. Samples of water, including dissolved and particulate fractions, as well as extracts of tegogolos, were screened using highly specific and sensitive ELISA. ELISA identified CYN and PST at low concentrations in only one sample of seston; however, both toxins were detected at appreciable quantities in tegogolos. Calculated bioaccumulation factors (BAF) support bioaccumulation of both toxins in tegogolos. The presence of CYN in the phytoplankton was further confirmed by HPLC-UV and LC-MS, following concentration and extraction of algal cells, but the toxin could not be confirmed by these methods in tegogolos. These data represent the first published evidence for CYN and the PST in Lago Catemaco and, indeed, for any freshwater system in Mexico. Identification of the apparent bioaccumulation of these toxins in tegogolos may suggest the need to further our understanding of the transfer of cyanobacterial toxins in freshwater food webs as it relates to human health. PMID:19651152

  16. Intralaboratory validation of a fast and sensitive UHPLC/MS/MS method with fast polarity switching for the analysis of lipophilic shellfish toxins.

    PubMed

    Braa-Magdalena, Ana; Leo-Martins, Jos Manuel; Glauner, Thomas; Gago-Martnez, Ana

    2014-01-01

    This paper shows the results of an intralaboratory validation of a fast method for the determination of lipophilic shellfish toxins working under acidic conditions using ultra-high performance LC (UHPLC) with MS/MS. Fourteen lipophilic marine toxins and domoic acid were acquired with fast polarity switching. Whereas azaspiracids (AZAs), pecenotoxins, 13-desmethyl spirolide C (SPX1), and gymnodimine were analyzed in the positive mode, yessotoxins (YTXs) were measured in negative mode. The okadaic acid (OA) group compounds were analyzed in both positive and negative ionization modes, and the accuracy of the results for both were compared. When using dynamic multiple reaction monitoring (MRM) in fast polarity switching, LODs were lower and reproducibility and linearity were better compared to static MRM. The UHPLC separation allowed for higher sample throughput in routine use. Compared to the previously used HPLC/MSIMS method, LODs were improved up to a factor of 10 in mussel extract. Matrix effects were evaluated by comparing standards prepared in solvent with matrix-matched calibrations in blank mussel extract. For accurate quantification matrix-matched calibrations were used when analyzing reference mussel materials, providing recoveries for OA, Dynophysis toxins (DTX)1, DTX2, YTX, AZA1, and SPX1 between 80 and 120% with RSDs below 8% over a 3-day validation procedure. PMID:24830138

  17. Exposure to the cyanotoxin microcystin arising from interspecific differences in feeding habits among fish and shellfish in the James River Estuary, Virginia.

    PubMed

    Wood, Joseph D; Franklin, Rima B; Garman, Greg; McIninch, Stephen; Porter, Aaron J; Bukaveckas, Paul A

    2014-05-01

    The cyanotoxin, microcystin (MC), is known to accumulate in the tissues of diverse aquatic biota although factors influencing exposure, such as feeding habits and seasonal patterns in toxin production, are poorly known. We analyzed seasonal variation in the MC content of primary and secondary consumers, and used dietary analysis (gut contents and stable isotopes) to improve understanding of cyanotoxin transport in food webs. Periods of elevated toxin concentration were associated with peaks in the abundance of genes specific to Microcystis and MC toxin production (mcyD). Peak toxin levels in consumer tissues coincided with peak MC concentrations in seston. However, toxins in tissues persisted in overwintering populations suggesting that potential health impacts may not be limited to bloom periods. Interspecific differences in tissue MC concentrations were related to feeding habits and organic matter sources as pelagic fishes ingested a greater proportion of algae in their diet, which resulted in greater MC content in liver and muscle tissues. Sediments contained a greater proportion of allochthonous (terrestrial) organic matter and lower concentrations of MC, resulting in lower toxin concentrations among benthic detritivores. Among shellfish, the benthic suspension feeder Rangia cuneata (wedge clam) showed seasonal avoidance of toxin ingestion due to low feeding rates during periods of elevated MC. Among predators, adult Blue Catfish had low MC concentrations, whereas Blue Crabs exhibited high levels of MC in both muscle and viscera. PMID:24694322

  18. Development of the analysis of fecal stanols in the oyster Crassostrea gigas and identification of fecal contamination in shellfish harvesting areas.

    PubMed

    Harrault, Loc; Jard, Emilie; Jeanneau, Laurent; Petitjean, Patrice

    2014-06-01

    The objective of this work was to study the effects of washing and purification steps on qualitative and quantitative analysis of fecal stanols in the oyster Crassostrea gigas using either single or a combination of lipid purification steps on silica gel or aminopropyl bonded silica gel (NH2) or a washing step. Among the three analytical pathways compared, the two including water extraction or NH2 purification did not lead to higher recoveries and decreased repeatabilities of extractions compared to the single purification on silica gel. This latter led to similar recoveries (ca. 80%) and repeatabilities (ca. 10%) for both spiked standards (coprostanol and sitostanol). This analytical pathway has been applied to oysters collected in a harvesting area in Brittany (France) where fecal contaminations are important and allowed to quantify eight stanols in oysters. The relative proportions of fecal stanols of these oysters were combined with principal component analysis in order to investigate the usefulness of their stanol fingerprints to record a fecal contamination and to distinguish its source between human, porcine and bovine contaminations. Oysters non-fecally contaminated by Escherichia coli did not present specific stanol fingerprints while oysters fecally contaminated had a bovine fingerprint, suggesting a contamination of these samples by bovine sources. As a consequence, the method developed here allows the use of stanol fingerprints of oysters as a microbial source tracking tool that can be applied to shellfish harvesting areas subjected to fecal contaminations in order to identify the different sources of contamination and improve watershed management. PMID:24771549

  19. Long-term impacts of human harvesting on shellfish: North Iberian top shells and limpets from the Upper Palaeolithic to the present

    NASA Astrophysics Data System (ADS)

    Turrero, Pablo; Muoz-Colmenero, A. Marta; Prado, Andrea; Garcia-Vazquez, Eva

    2014-11-01

    Humans have contributed to phenotypic and demographic changes in their prey from very early on in the colonization of Europe, including the harvesting of shellfish in coastal ecosystems. We estimated trends in population growth (variation in the number of individuals) from DNA sequences of modern specimens in two North Iberian molluscs, top shells (Osilinus lineatus, from 24 sequences and 14 haplotypes) and limpets (Patella vulgata, taken from the bibliography), which were subjected to very different levels of harvesting pressure during the Upper Palaeolithic (~ 20000 to ~ 6000 years ago). The less harvested Osilinus top shells experienced fluctuations in population numbers coincident with climatic oscillations. Patella limpets, which were harvested in greater numbers, suffered clear and uninterrupted decreases in their numbers during the Upper Palaeolithic. These trends coincided with morphological changes in shell size (length or width) in the same direction (i.e., shell size decreased when population size decreased and vice versa). The differing trends seen in taxa subjected to different intensities of harvesting pressure suggest that climate effects were overcome by anthropogenic selection (leading to a smaller average length) in limpets. We suggest that intense fishing pressure may have induced irreversible shell length decreases in the most exploited species.

  20. Confirmation of Pinnatoxins and Spirolides in Shellfish and Passive Samplers from Catalonia (Spain) by Liquid Chromatography Coupled with Triple Quadrupole and High-Resolution Hybrid Tandem Mass Spectrometry

    PubMed Central

    García-Altares, María; Casanova, Alexis; Bane, Vaishali; Diogène, Jorge; Furey, Ambrose; de la Iglesia, Pablo

    2014-01-01

    Cyclic imines are lipophilic marine toxins that bioaccumulate in seafood. Their structure comprises a cyclic-imino moiety, responsible for acute neurotoxicity in mice. Cyclic imines have not been linked yet to human poisonings and are not regulated in Europe, although the European Food Safety Authority requires more data to perform a conclusive risk assessment for consumers. This work presents the first detection of pinnatoxin G (PnTX-G) in Spain and 13-desmethyl spirolide C (SPX-1) in shellfish from Catalonia (Spain, NW Mediterranean Sea). Cyclic imines were found at low concentrations (2 to 60 µg/kg) in 13 samples of mussels and oysters (22 samples analyzed). Pinnatoxin G has been also detected in 17 seawater samples (out of 34) using solid phase adsorption toxin tracking devices (0.3 to 0.9 µg/kg-resin). Pinnatoxin G and SPX-1 were confirmed with both low and high resolution (<2 ppm) mass spectrometry by comparison of the response with that from reference standards. For other analogs without reference standards, we applied a strategy combining low resolution MS with a triple quadrupole mass analyzer for a fast and reliable screening, and high resolution MS LTQ Orbitrap® for unambiguous confirmation. The advantages and limitations of using high resolution MS without reference standards were discussed. PMID:24960460

  1. High Specificity of a Quantitative PCR Assay Targeting a Saxitoxin Gene for Monitoring Toxic Algae Associated with Paralytic Shellfish Toxins in the Yellow Sea.

    PubMed

    Gao, Yan; Yu, Ren-Cheng; Murray, Shauna A; Chen, Jian-Hua; Kang, Zhen-Jun; Zhang, Qing-Chun; Kong, Fan-Zhou; Zhou, Ming-Jiang

    2015-10-01

    The identification of core genes involved in the biosynthesis of saxitoxin (STX) offers a great opportunity to detect toxic algae associated with paralytic shellfish toxins (PST). In the Yellow Sea (YS) in China, both toxic and nontoxic Alexandrium species are present, which makes it a difficult issue to specifically monitor PST-producing toxic algae. In this study, a quantitative PCR (qPCR) assay targeting sxtA4, a domain in the sxt gene cluster that encodes a unique enzyme involved in STX biosynthesis, was applied to analyze samples collected from the YS in spring of 2012. The abundance of two toxic species within the Alexandrium tamarense species complex, i.e., A. fundyense and A. pacificum, was also determined with TaqMan-based qPCR assays, and PSTs in net-concentrated phytoplankton samples were analyzed with high-performance liquid chromatography coupled with a fluorescence detector. It was found that the distribution of the sxtA4 gene in the YS was consistent with the toxic algae and PSTs, and the quantitation results of sxtA4 correlated well with the abundance of the two toxic species (r=0.857). These results suggested that the two toxic species were major PST producers during the sampling season and that sxtA-based qPCR is a promising method to detect toxic algae associated with PSTs in the YS. The correlation between PST levels and sxtA-based qPCR results, however, was less significant (r=0.552), implying that sxtA-based qPCR is not accurate enough to reflect the toxicity of PST-producing toxic algae. The combination of an sxtA-based qPCR assay and chemical means might be a promising method for monitoring toxic algal blooms. PMID:26231652

  2. Partitioning of paralytic shellfish toxins in sub-cellular fractions of the digestive gland of the cockle Cerastoderma edule: Changes under post-bloom natural conditions.

    PubMed

    Botelho, Maria Joo; Raimundo, Joana; Vale, Carlos; Ferreira, Joo Gomes

    2014-06-01

    Concentrations of paralytic shellfish toxins (C1+2, B1, dcGTX2+3, dcSTX, GTX2+3 and STX) were determined by LC-FLD in composite samples of digestive glands of the cockle Cerastoderma edule and in each sub-cellular particulate fractions obtained after differential centrifugation (nuclei+debris, mitochondria, lysosomes and microsomes). The specimens were sampled during the exposure to a bloom of Gymnodinium catenatum (day 0) and in the subsequent 8, 12, 14, 19, 21 and 25 days under natural depuration conditions. Toxin profiles of digestive glands were dominated by C1+2 followed by B1 and dcGTX2+3, although the proportion between C1+2 and B1 contents decreased with the time, indicating a slower elimination of B1. All toxins, except GTX2+3 and STX, were quantified in the four sub-cellular fractions. The content of the quantified toxins decreased most markedly in nuclei+debris and microsomal fractions, during the first eight and 12 days, respectively. Conversely, different patterns were observed among toxins in mitochondrial and lysosomal fractions. The less accentuated decreases of dcGTX2+3 and dcSTX contents in the mitochondrial fraction may have resulted from the conversion of other toxins, like C1+2 and B1, associated with enzymatic activities in that fraction. The largest discrepancy was registered in lysosomal fraction for B1, since its content increased after eight days of post-bloom conditions. Input of B1 may come from the conversion of other toxins, like the abundant B2 and C1+2. These transformations are associated to the major role of lysosomes in the intra-cellular digestive process of materials acquired through vesicular transport. PMID:24736027

  3. Lipid, protein, and calorie content of different Atlantic and Mediterranean fish, shellfish, and molluscs commonly eaten in the south of Spain.

    PubMed

    Soriguer, F; Serna, S; Valverde, E; Hernando, J; Martín-Reyes, A; Soriguer, M; Pareja, A; Tinahones, F; Esteva, I

    1997-06-01

    We undertook a systematic evaluation of the lipid, protein, calorie, and fatty acid composition in 35 species of fish, shellfish and molluscs commonly consumed throughout the four seasons of the year in Andalusia, Spain. Using a portion of muscle tissue the following were measured in each study unit: total lipids (extraction using Folch's method and gravimetry), protein concentration (Kjehldal's method), total calories (direct calorimetry), and composition of fatty acids (gas chromatography). The lipid, protein, and different fatty acid concentrations found are presented in table form. There was a high degree of inter-species variability in the concentration of lipids and the various fatty acids. There was also a high degree of intra-species seasonal variability in some cases. The relative proportion of fatty acids was not independent of the total concentration of lipids, independently of the season studied. This systematic study of a large group of species shows that the cataloguing of fish as 'white' or 'blue' depends especially on the time of year they are captured. For example, in spring the mackerel (Scomber scombrus), a fish considered traditionally to be 'blue' (fatty), has the same lipid concentration as the dover sole (Solea vulgaris), commonly considered to be 'white' (little fat), and the sea pike (Merluccius merluccius) has a higher lipid concentration in autumn than the jack mackerel (Trachurus trachurus). Even greater differences existed when the fish were classified according to their richness in n-3 fatty acids. These differences in the total lipid concentration and the composition of fatty acids, as well as the inter-relations between them, may, under certain circumstances, be important for the calculation of dietary calories and nutritional values, and may explain the differences found between the various tables of food composition, as well as the divergent results in epidemiological studies on the association between fish in diets and various diseases, such as diabetes or ischaemic cardiopathy. PMID:9258553

  4. Photocatalytic properties of nanocrystalline titanium dioxide films in the degradation of domoic acid in aqueous solution: potential for use in molluscan shellfish biotoxin depuration facilities.

    PubMed

    Djaoued, Y; Robichaud, J; Thibodeau, M; Balaji, S; Tchoukanova, N; Bates, S S

    2009-02-01

    Domoic acid (DA) is a water-soluble marine neurotoxin produced and released by certain species of the diatom genus Pseudo-nitzschia. Present in coastal waters, it can be a threat to public health and marine life, and can result in severe economic losses to the molluscan shellfish and crustacean harvesting industries. Here we report on the efficiency of nanocrystalline (NC) titania (TiO(2)) thin films used as a photocatalyst in the ultraviolet light photodegradation of DA. Titanium dioxide thin films produced by a sol-gel dip-coating method in the presence of polyethylene glycol of different molecular weights (200, 400 and 600) were deposited on glass substrates and crystallised at 90 degrees C. The films were characterised using spectroscopic ellipsometry, Fourier transform infrared spectrometer (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy. The photocatalytic activity measurements were carried out by immersing the NC TiO(2) films in a DA solution (2500 ng ml(-1)) and then exposing them for various times at room temperature to UVA irradiation (lambda = approximately 350 nm). The degradation of DA, quantified by HPLC analysis, was not significant when using daylight or ultraviolet light irradiation alone, whereas the NC TiO(2) films prepared at low temperature proved to be a very efficient photocatalyst when used in conjunction with UVA light. The effectiveness of the photodegradation was improved by increasing molecular weight of polyethylene glycol, which increased the thickness of the film. The presence, transformation and degradation of three DA isomers were observed. The approach may eventually be practical for destroying DA in seawater used by aquaculture industry depuration facilities. PMID:19680896

  5. The interaction of human microbial pathogens, particulate material and nutrients in estuarine environments and their impacts on recreational and shellfish waters.

    PubMed

    Malham, Shelagh K; Rajko-Nenow, Paulina; Howlett, Eleanor; Tuson, Karen E; Perkins, Tracy L; Pallett, Denise W; Wang, Hui; Jago, Colin F; Jones, Davey L; McDonald, James E

    2014-09-20

    Anthropogenic activities have increased the load of faecal bacteria, pathogenic viruses and nutrients in rivers, estuaries and coastal areas through point and diffuse sources such as sewage discharges and agricultural runoff. These areas are used by humans for both commercial and recreational activities and are therefore protected by a range of European Directives. If water quality declines in these zones, significant economic losses can occur. Identifying the sources of pollution, however, is notoriously difficult due to the ephemeral nature of discharges, their diffuse source, and uncertainties associated with transport and transformation of the pollutants through the freshwater-marine interface. Further, significant interaction between nutrients, microorganisms and particulates can occur in the water column making prediction of the fate and potential infectivity of human pathogenic organisms difficult to ascertain. This interaction is most prevalent in estuarine environments due to the formation of flocs (suspended sediment) at the marine-freshwater interface. A range of physical, chemical and biological processes can induce the co-flocculation of microorganisms, organic matter and mineral particles resulting in pathogenic organisms becoming potentially protected from a range of biotic (e.g. predation) and abiotic stresses (e.g. UV, salinity). These flocs contain and retain macro- and micro- nutrients allowing the potential survival, growth and transfer of pathogenic organisms to commercially sensitive areas (e.g. beaches, shellfish harvesting waters). The flocs can either be transported directly to the coastal environment or can become deposited in the estuary forming cohesive sediments where pathogens can survive for long periods. Especially in response to storms, these sediments can be subsequently remobilised releasing pulses of potential pathogenic organisms back into the water column leading to contamination of marine waters long after the initial contamination event occurred. Further work, however, is still required to understand and predict the potential human infectivity of pathogenic organisms alongside the better design of early warning systems and surveillance measures for risk assessment purposes. PMID:25043898

  6. Determining the Advantages, Costs, and Trade-Offs of a Novel Sodium Channel Mutation in the Copepod Acartia hudsonica to Paralytic Shellfish Toxins (PST)

    PubMed Central

    Finiguerra, Michael; Avery, David E.; Dam, Hans G.

    2015-01-01

    The marine copepod Acartia hudsonica was shown to be adapted to dinoflagellate prey, Alexandrium fundyense, which produce paralytic shellfish toxins (PST). Adaptation to PSTs in other organisms is caused by a mutation in the sodium channel. Recently, a mutation in the sodium channel in A. hudsonica was found. In this study, we rigorously tested for advantages, costs, and trade-offs associated with the mutant isoform of A. hudsonica under toxic and non-toxic conditions. We combined fitness with wild-type: mutant isoform ratio measurements on the same individual copepod to test our hypotheses. All A. hudsonica copepods express both the wild-type and mutant sodium channel isoforms, but in different proportions; some individuals express predominantly mutant (PMI) or wild-type isoforms (PWI), while most individuals express relatively equal amounts of each (EI). There was no consistent pattern of improved performance as a function of toxin dose for egg production rate (EPR), ingestion rate (I), and gross growth efficiency (GGE) for individuals in the PMI group relative to individuals in the PWI expression group. Neither was there any evidence to indicate a fitness benefit to the mutant isoform at intermediate toxin doses. No clear advantage under toxic conditions was associated with the mutation. Using a mixed-diet approach, there was also no observed relationship between individual wild-type: mutant isoform ratios and among expression groups, on both toxic and non-toxic diets, for eggs produced over three days. Lastly, expression of the mutant isoform did not mitigate the negative effects of the toxin. That is, the reductions in EPR from a toxic to non-toxic diet for copepods were independent of expression groups. Overall, the results did not support our hypotheses; the mutant sodium channel isoform does not appear to be related to adaptation to PST in A. hudsonica. Other potential mechanisms responsible for the adaptation are discussed. PMID:26075900

  7. Profiles of paralytic shellfish toxins in bivalves of low and elevated toxicities following exposure to Gymnodinium catenatum blooms in Portuguese estuarine and coastal waters.

    PubMed

    Botelho, Maria Joo; Vale, Carlos; Ferreira, Joo Gomes

    2015-11-01

    Profiles of paralytic shellfish toxins (PSTs) were examined in 405 composite samples of Mytilus spp., Cerastoderma edule, Donax trunculus and Spisula solida collected between 2007 and 2012 from natural production areas in two estuaries (Aveiro and Mondego), two coastal lagoons (bidos and Formosa), and three open coastal areas (Aguda, Comporta and Culatra). Toxin concentrations were obtained from the biotoxin monitoring programme database. Episodes of PST toxicity in Portugal have been associated with Gymnodinium catenatum blooms. Toxin profiles for each species showed no trend over the surveyed years. In general, profiles differ only slightly among areas, except for bidos. However, toxin profiles in bivalves varied between low and elevated toxicities, corresponding to below and above the PST regulatory limit, respectively. The ratio R1=(C1+2):B1, which were the main toxins produced by G. catenatum cells, decreased considerably between elevated and low toxicity cockles, indicating the elimination of C1+2 or conversion of compounds into B1. R2=[(dcSTX)+(dcGTX2+3)]:[(C1+2)+(B1)], which represents the ratio of minor to major toxins in G. catenatum cells, increased substantially in wedge clams (D. trunculus) of low toxicity and less markedly in cockles (C. edule) and mussels (Mytilus spp.). These differences are interpreted as the predominance of a biotransformation phase after exposure to the algal bloom. The toxin profile of surf clams (S. solida) was dominated by decarbamoyl compounds, reflecting intense biotransformation during exposure to blooms. The higher ratio R2 in low toxicity samples suggests that elimination of the produced decarbamoyl toxins was slower than biotransformation. PMID:25616737

  8. Contrasting Physiological Responses of Two Populations of the Razor Clam Tagelus dombeii with Different Histories of Exposure to Paralytic Shellfish Poisoning (PSP)

    PubMed Central

    Navarro, Jorge M.; González, Katerina; Cisternas, Barbara; López, Jorge A.; Chaparro, Oscar R.; Segura, Cristian J.; Córdova, Marco; Suárez-Isla, Benjamín; Fernandez-Reiriz, María J.; Labarta, Uxio

    2014-01-01

    This study describes the physiological performance of two populations of the razor clam Tagelus dombeii from two geographic areas with different histories of exposure to paralytic shellfish poisoning (PSP) linked to the toxic dinoflagellate Alexandrium catenella. Clams from Melinka-Aysén, which are frequently exposed to PSP, were not affected by the presence of toxins in the diet. However, clams from Corral-Valdivia, which have never been exposed to PSP, exhibited significantly reduced filtration activity and absorption, affecting the energy allocated to scope for growth (SFG). Ammonia excretion and oxygen uptake were not affected significantly by the presence of A. catenella in the diet. Measurements of energy acquisition and expenditure were performed during a 12-day intoxication period. According to three-way repeated measure ANOVAs, the origin of the clams had a highly significant effect on all physiological variables, and the interaction between diet and origin was significant for the clearance and absorption rates and for the scope for growth. The scope for growth index showed similar positive values for both the toxic and non-toxic individuals from the Melinka-Aysén population. However, it was significantly reduced in individuals from Corral-Valdivia when exposed to the diet containing A. catenella. The absence of differences between the physiological response of the toxic and non-toxic clams from Melinka-Aysén may be related to the frequent presence of A. catenella in the environment, indicating that this bivalve does not suffer negative consequences from PSP. By contrast, A. catenella has a negative effect on the physiological performance, primarily on the energy gained from the environment, on T. dombeii from Corral-Valdivia. This study supports the hypothesis that the history of PSP exposure plays an important role in the physiological performance and fitness of filter feeding bivalves. PMID:25153329

  9. Implication of brevetoxin B1 and PbTx-3 in neurotoxic shellfish poisoning in New Zealand by isolation and quantitative determination with liquid chromatography-tandem mass spectrometry.

    PubMed

    Nozawa, Akira; Tsuji, Kuniro; Ishida, Hitoshi

    2003-07-01

    Brevetoxin B1 (BTX-B1) was isolated from Austrovenus stutchburyi following the 1992-1993 outbreak of neurotoxic shellfish poisoning (NSP) in New Zealand. We report here the first isolation of PbTx-3 from the same shellfish and the development of a procedure for quantitative determination of PbTx-3 and BTX-B1. PbTx-3 was isolated by chromatography on columns of SiO2, ODS, and LH-20, followed by reverse-phase HPLCs. In mass spectrometry (MS) with an electrospray ionization (ESI) interface operating in the positive or negative ion mode, the abundant protonated ion [M+H]+ of PbTx-3 (m/z 897) and the de-sodiated ion [M-Na]- of BTX-B1 (m/z 1016) were generated, respectively. These served as precursor ions for collision-induced dissociation, and the product ions of m/z 725 from PbTx-3 and m/z 80 from BTX-B1 were identified, allowing unambiguous confirmation of these toxins by selected reaction monitoring liquid chromatography-tandem mass spectrometry (SRM LC-MS/MS) analysis. The determination limits were 0.4 and 2 ng/g for BTX-B1 and PbTx-3 at a signal-to-noise ratio of five, respectively. This LC-MS/MS method was successfully applied to determine BTX-B1 and PbTx-3 in the NSP-associated toxic shellfish. BTX-B1 was found in both A. stutchburyi and Perna canaliculus, but not in Crassostrea gigas, while PbTx-3 was found in all three. PMID:12893066

  10. Metal-organic framework UiO-66 modified magnetite@silica core-shell magnetic microspheres for magnetic solid-phase extraction of domoic acid from shellfish samples.

    PubMed

    Zhang, Wenmin; Yan, Zhiming; Gao, Jia; Tong, Ping; Liu, Wei; Zhang, Lan

    2015-06-26

    Fe3O4@SiO2@UiO-66 core-shell magnetic microspheres were synthesized and characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectrometry, vibrating sample magnetometry, nitrogen adsorption porosimetry and zeta potential analyzer. The synthesized Fe3O4@SiO2@UiO-66 microspheres were first used for magnetic solid-phase extraction (MSPE) of domoic acid (DA) in shellfish samples. Combined with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), a fast, simple and sensitive method for the determination of DA was established successfully. Under the optimized conditions, the developed method showed short analysis time, good linearity (r(2) = 0.9990), low limit of detection (1.45 pg mL(-1); S/N = 3:1), low limit of quantification (4.82 pg mL(-1); S/N = 10:1), and good extraction repeatability (RSD ≤ 5.0%; n = 5). Real shellfish samples were processed using the developed method, and trace level of DA was detected. The results demonstrate that Fe3O4@SiO2@UiO-66 core-shell magnetic microspheres are the promising sorbents for rapid and efficient extraction of polar analytes from complex biological samples. PMID:25997847

  11. Development of the fecal coliform total maximum daily load using Loading Simulation Program C++ and tidal prism model in estuarine shellfish growing areas: a case study in the Nassawadox coastal embayment, Virginia.

    PubMed

    Shen, Jian; Sun, Shucun; Wang, Taiping

    2005-01-01

    In this study, a linked model system including the Loading Simulation Program C++ (LSPC) and the tidal prism water quality model (TPWQM) was proposed as an alternative tool for total maximum daily load (TMDL) studies. The feasibility of the model system was tested by a case study in the Nassawadox Creek, a Virginia tidal water shellfish growing area. The watershed model, driven by hourly precipitation, simulates hydrology and fecal coliform accumulation and transport processes in the watershed. The simulated surface runoff and subsurface flow as well as fecal coliform loads from the watershed are discharged to the tidal creek. The tidal prism model simulates fecal coliform transport in the Creek. The model results demonstrate the effectiveness in simulating hydrology and fecal coliform concentration in the watershed and its embayment. A series of sensitivity runs was conducted to estimate the load reduction necessary for fecal coliform concentration to meet the water quality standards. The model application to the Nassawadox Creek indicates that the model system is useful in developing fecal coliform TMDLs for estuarine shellfish growing areas. PMID:16134369

  12. 239 + 240Pu and 137Cs concentrations in fish, cephalopods, crustaceans, shellfish, and algae collected around the Japanese coast in the early 1990s.

    PubMed

    Yamada, M; Aono, T; Hirano, S

    1999-10-01

    Marine organisms, i.e. fish, cephalopods, crustaceans, shellfish, and algae, were collected in the early 1990s along the Sea of Japan coast and the Japanese Pacific coast and analyzed for their 239 + 240Pu and 137Cs concentrations. The 239 + 240Pu concentrations in muscle of fish were below 0.4 mBq/kg wet wt. and the lowest among the analyzed marine organisms. Most 137Cs concentrations in muscle of fish ranged from 100 to 300 mBq/kg wet wt. Higher concentrations of 239 + 240Pu, ranging from 1.6 to 5.7 mBq/kg wet wt., were observed in viscera of cephalopods than in their muscle. The 239 + 240Pu concentrations in whole soft tissues of bivalves varied approximately one order of magnitude from 0.8 to 6.1 mBq/kg wet wt., while 137Cs concentrations had little variation, being approximately 60 mBq/kg wet wt. The 239 + 240Pu concentrations in algae had a wide variation, ranging from 1.7 to 42.3 mBq/kg wet wt., and were higher than those of the other marine organisms. No statistically significant difference in mean concentrations of 239 + 240Pu was detected among the whole soft tissues of bivalves, viscera of cephalopods and crustaceans, and whole bodies of cephalopods and crustaceans within the 95% confidence limit. The mean concentrations of 137Cs became higher in the order, cephalopods and crustaceans and bivalves, algae, viscera of fish, muscles of fish. The mean concentrations of 239 + 240Pu were comparable for algae collected along the Japan Sea coast and the Pacific coast. Furthermore, the difference in mean concentrations of 137Cs in algae between the Japan Sea coast and the Pacific coast was not statistically significant within the 95% confidence limit. These results can be considered to indicate no definite influence from radioactive dumping into the Japan Sea by the former USSR and Russia with respect to radioactive pollution of marine organisms collected along the Japanese coast. PMID:10570839

  13. Analysis of diarrhetic shellfish poisoning toxins and pectenotoxin-2 in the bottlenose dolphin (Tursiops truncatus) by liquid chromatography-tandem mass spectrometry.

    PubMed

    Wang, Zhihong; Broadwater, Margaret H; Ramsdell, John S

    2015-10-16

    Toxins produced by harmful algae are associated with detrimental health effects and mass mortalities of marine mammals. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is generally used to confirm the presence of algal toxins in marine mammals. Sample preparation and LC-MS/MS methods for the determination of three diarrhetic shellfish poisoning (DSP) toxins (okadaic acid, OA; dinophysistoxin-1, DTX1; dinophysistoxin-2, DTX2) and pectenotoxin-2 (PTX2) in bottlenose dolphin (Tursiops truncatus) urine and tissue samples were evaluated using spike-and-recovery tests. Sample clean-up with either reversed-phase silica or polymeric solid-phase extraction (SPE) reduced interference of sample matrices and improved toxin recoveries, with polymeric SPE showing higher sample loading capacity. LC separation on Xbridge C18 columns using acetonitrile/water gradient elutions with ammonia as the additive was chosen for its high detectivity and sensitivity in the MS detection of DSP toxins in negative ion mode. The retention times of OA, DTX1, and DTX2, separated as negative ions, increased with LC column temperature while the retention time of PTX2, separated as the neutral molecule, was weakly affected. At the same column temperature, retention times of OA, DTX1, and DTX2 gradually increased as the mobile phases aged while the retention time of PTX2 remained unchanged; higher column temperatures resulted in a greater increase in the retention time of each DSP toxin with mobile phase aging. Average recoveries of the 4 toxins in bottlenose dolphin samples ranged from 80% to 130% with relative standard deviations of less than 15% using the LC mobile phases prepared within one week at a column temperature of 30°C or 40°C. The preferred column temperature was 30°C, as the retention times of DSP toxins were less affected by mobile phase aging at this temperature. The limit of detection of each toxin analyzed in bottlenose dolphin samples was 2.8 ng/g or less in tissue samples and 0.7 ng/ml or less in urine. PMID:26381568

  14. Improving early detection of exotic or emergent oyster diseases in France: identifying factors associated with shellfish farmer reporting behaviour of oyster mortality.

    PubMed

    Lupo, C; Osta Amigo, A; Mandard, Y V; Peroz, C; Renault, T

    2014-09-01

    Farmers' vigilance is essential for the detection of epidemics, including potential emerging diseases, in marine shellfish. A field study was conducted to investigate oyster farmers' reporting practices and behaviour, and to identify factors influencing the reporting process of oyster mortality, with the ultimate aim of improving early detection of unexplained oyster mortality outbreaks. A retrospective case-control study of oyster farmers from Charente-Maritime (France) was designed, based on interviews with 27 non-reporting and 89 reporting farmers, further split into 40 formerly-reporting and 49 currently-reporting farmers. Information about farmer and farm characteristics, farming practices, farm health history and related financial compensation on the farm, knowledge of the mortality reporting system and reporting behaviour was collected. Sampling design was considered in the calculations and farmers' reporting behaviour was modelled using an ordinal logistic regression (continuation-ratio model). Notification procedures were fairly well known among farmers and the reporting system was well accepted overall. Nevertheless, a lack of awareness of the aims of the reporting system was revealed, which contributed to late reporting. Factors identified as driving a farmer's decision to report oyster mortality concerned their lack of awareness of mortality reporting (production type, farm size, location of the production cycle, accessibility of the leasing grounds) and willingness to report (possibility and extent of financial compensation, a feeling of not being involved, whether it was first year of reporting). Overall classification performance of the model built in this study was 64%. In particular, financial compensation for oyster production losses appeared to be a clear incentive for reporting, but was countered by a habituation effect combined with a lack of awareness of the aims of the reporting system: oyster farmers looking for benefits for themselves in reporting, rather than early detection of a disease outbreak. Both economic compensation and the farmers' non-economic values and perceptions should be considered to improve oyster farmers' reporting compliance and sustainability of the reporting system. Education and participatory approaches could help to change these attitudes and thus improve oyster farmers' compliance with reporting duties, resulting in improved early detection of epidemics and emerging or exotic oyster diseases. PMID:24880624

  15. Improved microwave-assisted wet digestion procedures for accurate Se determination in fish and shellfish by flow injection-hydride generation-atomic absorption spectrometry.

    PubMed

    Lavilla, I; González-Costas, J M; Bendicho, C

    2007-05-22

    Accurate determination of Se in biological samples, especially fish and shellfish, by hydride generation techniques has generally proven troublesome owing to the presence of organoselenium that cannot readily converted into inorganic selenium under usual oxidising conditions. Further improvements in the oxidation procedures are needed so as to obtain accurate concentration values when this type of samples is analyzed. Microwave-assisted wet digestion (MAWD) procedures of seafood based on HNO3 or the mixture HNO3/H2O2 and further thermal reduction of the Se(VI) formed to Se(IV) were evaluated. These procedures were as follows: (I) without H2O2 and without heating to dryness; (II) without H2O2 and with heating to dryness; (III) with H2O2 and without heating to dryness; (IV) with H2O2 and with heating to dryness. In general, low recoveries of selenium are obtained for several marine species (e.g., crustaceans and cephalopods), which may be ascribed to the presence of Se forms mainly associated with nonpolar proteins and lipids. Post-digestion UV irradiation proved very efficient since not only complete organoselenium decomposition was achieved but also the final step required for prereduction of Se(VI) into Se(IV) (i.e. heating at 90 degrees C for 30 min in 6M HCl) could be avoided. With the MAWD/UV procedure, the use of strong oxidising agents (persuphate, etc.) or acids (e.g. perchloric acid) which are typically applied prior to Se determination by hydride generation techniques is overcome, and as a result, sample pre-treatment is significantly simplified. The method was successfully validated against CRM DOLT-2 (dogfish liver), CRM DORM-2 (dogfish muscle) and CRM TORT-2 (lobster hepatopancreas). Automated ultrasonic slurry sampling with electrothermal atomic absorption spectrometry was also applied for comparison. Total Se contents in ten seafood samples were established. Se levels ranged from 0.7 to 2.9 microg g(-1). PMID:17481413

  16. Paralytic shellfish toxins in the sea scallop Placopecten magellanicus on Georges Bank: Implications for an offshore roe-on and whole scallop fishery

    NASA Astrophysics Data System (ADS)

    DeGrasse, Stacey; Vanegas, Camilo; Conrad, Stephen

    2014-05-01

    To protect public health from the potential risk of paralytic shellfish poisoning (PSP) in sea scallops, Placopecten magellanicus, from the Atlantic offshore U.S. waters of Georges Bank, harvesting of roe-on or whole scallops is banned. Only adductor muscles may be sold if harvested from Georges Bank, Gulf of Maine, or the PSP closure areas as far west as 71° West Longitude. Given the limited toxicity data available for sea scallops from this region both prior to and subsequent to implementation of this management strategy, this study sought a more extensive spatial and temporal evaluation of sea scallop gonad and viscera toxicities that would inform management decisions related to the roe-on and whole scallop fishery. Both overall toxicity and toxin composition were measured for sea scallop gonads and viscera collected from 232 stations in 2007 and 23 in 2010. Overall toxicity was assessed using two screening methods: field-deployable Jellett Rapid Tests (JRT) and quantitative, laboratory-based receptor binding assays (in 2007). Additionally, a quantitative liquid chromatography with fluorescence detection (LC-FD) method was used to determine toxin composition and overall toxicity (in 2010). The at-sea qualitative JRT screening tool results, whereby a positive indicated the sample contained at least 40 μg saxitoxin (STX) equivalents 100 g-1, were often inconsistent with results obtained using the quantitative methods. Sea scallop viscera toxicity represented the majority of toxin load in the organism and was often in excess of the regulatory guidance level. Sea scallop gonads accounted for a small percentage of total toxicity, but at times reached unsafe levels. Toxin composition in both the gonads and viscera was dominated by STX and gonyautoxin 2/3, as has been reported in previous studies. No predictive indices of gonad toxicity were found. Results at this time do not support a roe-on or whole scallop fishery on Georges Bank. While access restrictions to whole scallops on Georges Bank are unlikely to change based on these results, it seems plausible that a management strategy requiring at-sea testing of scallop gonads for PSP may be necessary in order for a safe roe-on scallop fishery from this region to be feasible.

  17. Hemigrapsus sanguineus in Long Island salt marshes: experimental evaluation of the interactions between an invasive crab and resident ecosystem engineers

    PubMed Central

    Fournier, Alexa M.; Furman, Bradley T.; Carroll, John M.

    2014-01-01

    The invasive Asian shore crab, Hemigrapsus sanguineus, has recently been observed occupying salt marshes, a novel environment for this crab species. As it invades this new habitat, it is likely to interact with a number of important salt marsh species. To understand the potential effects of H. sanguineus on this ecosystem, interactions between this invasive crab and important salt marsh ecosystem engineers were examined. Laboratory experiments demonstrated competition for burrows between H. sanguineus and the native fiddler crab, Uca pugilator. Results indicate that H. sanguineus is able to displace an established fiddler crab from its burrow. Feeding experiments revealed that the presence of H. sanguineus has a significantly negative impact on the number as well as the biomass of ribbed mussels (Geukensia demissa) consumed by the green crab, Carcinus maenas, although this only occurred at high predator densities. In addition, when both crabs foraged together, there was a significant shift in the size of mussels consumed. These interactions suggests that H. sanguineus may have long-term impacts and wide-ranging negative effects on the saltmarsh ecosystem. PMID:25071995

  18. Hemigrapsus sanguineus in Long Island salt marshes: experimental evaluation of the interactions between an invasive crab and resident ecosystem engineers.

    PubMed

    Peterson, Bradley J; Fournier, Alexa M; Furman, Bradley T; Carroll, John M

    2014-01-01

    The invasive Asian shore crab, Hemigrapsus sanguineus, has recently been observed occupying salt marshes, a novel environment for this crab species. As it invades this new habitat, it is likely to interact with a number of important salt marsh species. To understand the potential effects of H. sanguineus on this ecosystem, interactions between this invasive crab and important salt marsh ecosystem engineers were examined. Laboratory experiments demonstrated competition for burrows between H. sanguineus and the native fiddler crab, Uca pugilator. Results indicate that H. sanguineus is able to displace an established fiddler crab from its burrow. Feeding experiments revealed that the presence of H. sanguineus has a significantly negative impact on the number as well as the biomass of ribbed mussels (Geukensia demissa) consumed by the green crab, Carcinus maenas, although this only occurred at high predator densities. In addition, when both crabs foraged together, there was a significant shift in the size of mussels consumed. These interactions suggests that H. sanguineus may have long-term impacts and wide-ranging negative effects on the saltmarsh ecosystem. PMID:25071995

  19. Chelal Characteristics and Foraging Behaviour of the Blue Crab Callinectes sapidusRathbun

    NASA Astrophysics Data System (ADS)

    Seed, R.; Hughes, R. N.

    1997-02-01

    This paper describes the morphological and mechanical characteristics of the chelae of Callinectes sapidus, together with the predation techniques, handling times and prey size selection of this voracious predator when presented with marsh mussels, Geukensia demissa, or fiddler crabs, Uca pugilator, in laboratory aquaria. Callinectes sapidusis heterochelous but differences in claw size and mechanical advantage between male and female crabs are statistically indistinguishable. Handling times for mussels and fiddler crabs increased steeply with prey size. Fiddler crabs are intrinsically more profitable than mussels, but the relative costs of capturing mobile prey, or excavating mussels, in natural populations is unknown. Previous laboratory experiments investigating the key stimuli used by C. sapiduswhen selecting prey are reviewed, and their results are compared with behaviour predicted by optimal foraging theory. It is concluded that crabs respond to the strongest stimuli received from the prey. Items were rejected after a given persistence time if the attack proved unsuccessful. Persistence time, however, was adjusted through experience to expectations of local prey quality and availability. The integrated result of this key-stimulus mechanism will be a close match to diets predicted by other behavioural models, including that based on optimal foraging theory.

  20. Foundation species' overlap enhances biodiversity and multifunctionality from the patch to landscape scale in southeastern United States salt marshes.

    PubMed

    Angelini, Christine; van der Heide, Tjisse; Griffin, John N; Morton, Joseph P; Derksen-Hooijberg, Marlous; Lamers, Leon P M; Smolders, Alfons J P; Silliman, Brian R

    2015-07-22

    Although there is mounting evidence that biodiversity is an important and widespread driver of ecosystem multifunctionality, much of this research has focused on small-scale biodiversity manipulations. Hence, which mechanisms maintain patches of enhanced biodiversity in natural systems and if these patches elevate ecosystem multifunctionality at both local and landscape scales remain outstanding questions. In a 17 month experiment conducted within southeastern United States salt marshes, we found that patches of enhanced biodiversity and multifunctionality arise only where habitat-forming foundation species overlap--i.e. where aggregations of ribbed mussels (Geukensia demissa) form around cordgrass (Spartina alterniflora) stems. By empirically scaling up our experimental results to the marsh platform at 12 sites, we further show that mussels--despite covering only approximately 1% of the marsh surface--strongly enhance five distinct ecosystem functions, including decomposition, primary production and water infiltration rate, at the landscape scale. Thus, mussels create conditions that support the co-occurrence of high densities of functionally distinct organisms within cordgrass and, in doing so, elevate salt marsh multifunctionality from the patch to landscape scale. Collectively, these findings suggest that patterns in foundation species' overlap drive variation in biodiversity and ecosystem functioning within and across natural ecosystems.We therefore argue that foundation species should be integrated in our conceptual understanding of forces that moderate biodiversity--ecosystem functioning relationships, approaches for conserving species diversity and strategies to improve the multifunctionality of degraded ecosystems. PMID:26136442

  1. An innovative method based on quick, easy, cheap, effective, rugged, and safe extraction coupled to desorption electrospray ionization-high resolution mass spectrometry for screening the presence of paralytic shellfish toxins in clams.

    PubMed

    Mattarozzi, Monica; Bianchi, Federica; Milioli, Marco; Cavazza, Antonella; Careri, Maria

    2016-01-15

    The capabilities of desorption electrospray ionization-high resolution mass spectrometry (DESI-HRMS) were tested for screening the presence of some paralytic shellfish toxins in clams. A quick, easy, cheap, effective, rugged, and safe (QuEChERS) approach is proposed for sample clean-up. QuEChERS extraction was optimized by using a full factorial design followed by the multicriteria method of the desirability functions. Quantitation limits in the microgram per kilogram range proved reliability of the method for the detection of the investigated toxins in accordance to the rules laid down by European legislation. The optimized QuEChERS-DESI-HRMS based-method allowed for a rapid reliable screening of the investigated compounds at levels of interest, thus being useful for high-throughput analyses. PMID:26592627

  2. Database of radionuclide measurements in Columbia River water, fish, waterfowl, gamebirds, and shellfish downstream of Hanford`s single-pass production reactors, 1960--1970. Hanford Environmental Dose Reconstruction Project

    SciTech Connect

    Thiede, M.E.; Duncan, J.P.

    1994-03-01

    This report is a result of the Hanford Environmental Dose Reconstruction (HEDR) Project. The goal of the HEDR Project is to estimate the radiation dose that individuals could have received from radionuclide emissions since 1944 at the Hanford Site near Richland, Washington. The HEDR Project is conducted by Battelle, Pacific Northwest Laboratories. The time periods of greatest interest to the HEDR study vary depending on the type of environmental media concerned. Concentrations of radionuclides in Columbia River media from 1960--1970 provide the best historical data for validation of the Columbia River pathway computer models. This report provides the historical radionuclide measurements in Columbia River water (1960--1970), fish (1960--1967), waterfowl (1960--1970), gamebirds (1967--1970), and shellfish (1960--1970). Because of the large size of the databases (845 pages), this report is being published on diskette. A diskette of this report is available from the Technical Steering Panel (c/o K. CharLee, Office of Nuclear Waste Management, Department of Ecology, Technical Support and Publication Information Section, P.O. Box 47651, Olympia, Washington 98504-7651).

  3. Using bivalves as particle collectors with PCR detection to investigate the environmental distribution of Haplosporidium nelsoni.

    PubMed

    Ford, Susan E; Allam, Bassem; Xu, Zhe

    2009-02-12

    Recently, PCR technology has been applied to search for marine microorganisms in environmental samples. Such sampling, however, has drawbacks, including the need to collect and filter large volumes of water, and the presence of substances in environmental samples that may destroy DNA or interfere with DNA isolation and amplification. We explored the possibility of using suspension-feeding bivalves in conjunction with PCR to investigate the environmental distribution of microparasites using the oyster pathogen Haplosporidium nelsoni (the MSX disease agent) with oysters and mussels in Delaware Bay, USA, as a model system. Delaware Bay oysters Crassostrea virginica have become very resistant to H. nelsoni infection development and rarely exhibit histologically detectable lesions. The ribbed mussel Geukensia demissa is also resistant. Infections were detected in only 6% of the histologically examined oysters in the present study, although PCR-positive signals for H. nelsoni were found in feces, gill or heart samples of up to 100% of oysters. Positive signals were found in the feces and gill (but not heart) samples of up to 50% of mussels. The temporal evolution of PCR signals suggested a wave-like pattern of putative infective particles, which mimicked a pattern documented in early mortality studies. The present study demonstrated that H. nelsoni persists throughout Delaware Bay, although it is rarely detected using standard histology. We propose that the use of suspension-feeding bivalves as particle collectors in combination with PCR could be a method for detecting the presence of marine microparasites and might help answer questions about factors that prevent outbreaks of epizootics in certain regions. PMID:19326797

  4. Restricting Prey Dispersal Can Overestimate the Importance of Predation in Trophic Cascades

    PubMed Central

    Geraldi, Nathan R.; Macreadie, Peter I.

    2013-01-01

    Predators can affect prey populations and, via trophic cascades, predators can indirectly impact resource populations (2 trophic levels below the predator) through consumption of prey (density-mediated indirect effects; DMIEs) and by inducing predator-avoidance behavior in prey (trait-mediated indirect effects; TMIEs). Prey often employ multiple predator-avoidance behaviors, such as dispersal or reduced foraging activity, but estimates of TMIEs are usually on individual behaviors. We assessed direct and indirect predator effects in a mesocosm experiment using a marine food chain consisting of a predator (toadfish Opsanus tau), prey (mud crab - Panopeus herbstii) and resource (ribbed mussel Geukensia demissa). We measured dispersal and foraging activity of prey separately by manipulating both the presence and absence of the predator, and whether prey could or could not disperse into a predator-free area. Consumption of prey was 9 times greater when prey could not disperse, probably because mesocosm boundaries increased predator capture success. Although predator presence did not significantly affect the number of crabs that emigrated, the presence of a predator decreased resource consumption by prey, which resulted in fewer resources consumed for each prey that emigrated in the presence of a predator, and reduced the overall TMIE. When prey were unable to disperse, TMIEs on mussel survival were 3 times higher than the DMIEs. When prey were allowed to disperse, the TMIEs on resource survival increased to 11-times the DMIEs. We found that restricting the ability of prey to disperse, or focusing on only one predator-avoidance behavior, may be underestimating TMIEs. Our results indicate that the relative contribution of behavior and consumption in food chain dynamics will depend on which predator-avoidance behaviors are allowed to occur and measured. PMID:23408957

  5. Zoonotic infections from fish and shellfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The worldwide development of aquaculture and the worldwide transport of live aquaculture products has, apart from many advantages, also worrisome consequences. Among them is the occurrence and increased recognition of zoonotic disease agents causing epidemics and carrier states in cultured fish and ...

  6. Activity measurements of a suite of radionuclides (241Am, 239,240Pu, 238Pu, 238U, 234U, 235U, 232Th, 230Th, 228Th, 228Ra, 137Cs, 210Pb, 90Sr and 40K) in biota reference material (Ocean Shellfish): CCRI(II)-S3

    NASA Astrophysics Data System (ADS)

    Nour, S.; Karam, L. R.; Inn, K. G. W.

    2012-01-01

    In 2005, the CCRI decided that a comparison undertaken from 2002 to 2008 by the NIST (under the auspices of the Inter-America Metrology System [SIM]) in the development of a new biota (Ocean Shellfish) standard reference material (SRM) was sufficiently well constructed that it could be converted into a supplementary comparison under CCRI(II), with comparison identifier CCRI(II)-S3. This would enable the comparison to be used to support calibration and measurement capability (CMC) claims for radionuclide measurements in reference materials (specifically, animal-based organic materials). Previous comparisons of radionuclides have been of single or multiple nuclides in non-complex matrices and results of such could not be extended to support capabilities to measure the same nuclides in reference materials. The results of this comparison have been used to determine the certified reference value of the SRM. The key comparison working group (KCWG) of the CCRI(II) has approved this approach as a mechanism to link all the results to certified 'reference values' in lieu of the key comparison reference value (KCRV) of these specified radionuclides in this type of matrix (shellfish) so as to support CMCs of similar materials submitted by the present participants. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  7. Comparative concentrations of brevetoxins PbTx-2, PbTx-3, BTX-B1 and BTX-B5 in cockle, Austrovenus stutchburyi, greenshell mussel, Perna canaliculus, and Pacific oyster, Crassostrea gigas, involved neurotoxic shellfish poisoning in New Zealand.

    PubMed

    Ishida, Hitoshi; Nozawa, Akira; Nukaya, Haruo; Tsuji, Kuniro

    2004-06-01

    Previously, we found brevetoxins PbTx-3, BTX-B5 and BTX-B1 in cockle, Austrovenus (A.) stutchburyi, PbTx-2, PbTx-3 and BTX-B1 in Pacific oyster, Crassostrea (C.) gigas and PbTx-3 and BTX-B1 in greenshell mussel, Perna (P.) canaliculus following outbreak of neurotoxic shellfish poisoning (NSP) in New Zealand by isolation and/or liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). In this study, procedures for quantitative determination of PbTx-2 and BTX-B5 were developed and those for PbTx-3 and BTX-B1 were further examined by LC-MS/MS. In mass spectrometry with an electrospray ionization interface operating in the positive or negative ion mode, the protonated ions [M+H]+ of PbTx-2 (m/z 895), [M+H]+ of PbTx-3 (m/z 897), [M-H]- of BTX-B5 (m/z 909), and [M-Na]- of BTX-B1 (m/z 1016) were generated abundantly, when 0.1% formic acid-acetonitrile was used as the mobile phase for column chromatography. The product ions of m/z 877, 725, 111 and 80 from PbTx-2, PbTx-3, BTX-B5 and BTX-B1 were identified, respectively, allowing unambiguous confirmation of these toxins by selective reaction monitoring LC-MS/MS analysis. High levels of PbTx-3 and BTX-B5 were detected in C. gigas, of PbTx-3, BTX-B1 and BTX-B5 in A. stutchburyi, and of PbTx-2, PbTx-3 and BTX-B5 in P. canaliculus by this LC-MS/MS method. PMID:15284012

  8. Archaeological shellfish size and later human evolution in Africa

    PubMed Central

    Klein, Richard G.; Steele, Teresa E.

    2013-01-01

    Approximately 50 ka, one or more subgroups of modern humans expanded from Africa to populate the rest of the world. Significant behavioral change accompanied this expansion, and archaeologists commonly seek its roots in the African Middle Stone Age (MSA; ∼200 to ∼50 ka). Easily recognizable art objects and “jewelry” become common only in sites that postdate the MSA in Africa and Eurasia, but some MSA sites contain possible precursors, especially including abstractly incised fragments of ocher and perforated shells interpreted as beads. These proposed art objects have convinced most specialists that MSA people were behaviorally (cognitively) modern, and many argue that population growth explains the appearance of art in the MSA and its post-MSA florescence. The average size of rocky intertidal gastropod species in MSA and later coastal middens allows a test of this idea, because smaller size implies more intense collection, and more intense collection is most readily attributed to growth in the number of human collectors. Here we demonstrate that economically important Cape turban shells and limpets from MSA layers along the south and west coasts of South Africa are consistently and significantly larger than turban shells and limpets in succeeding Later Stone Age (LSA) layers that formed under equivalent environmental conditions. We conclude that whatever cognitive capacity precocious MSA artifacts imply, it was not associated with human population growth. MSA populations remained consistently small by LSA standards, and a substantial increase in population size is obvious only near the MSA/LSA transition, when it is dramatically reflected in the Out-of-Africa expansion. PMID:23776248

  9. Should I Be Concerned about Eating Fish and Shellfish?

    MedlinePLUS

    ... menu Learn the Issues Air Chemicals and Toxics Climate Change Emergencies Greener Living Health and Safety Land and Cleanup Pesticides Waste Water Science & Technology Air Climate Change Ecosystems Health Land, Waste and Cleanup Pesticides Substances ...

  10. Committed effective dose from naturally occuring radionuclides in shellfish

    NASA Astrophysics Data System (ADS)

    Khandaker, Mayeen Uddin; Wahib, Norfadira Binti; Amin, Yusoff Mohd.; Bradley, D. A.

    2013-07-01

    Recognizing their importance in the average Malaysian daily diet, the radioactivity concentrations in mollusc- and crustacean-based food have been determined for key naturally occuring radionuclides. Fresh samples collected from various maritime locations around peninsular Malaysia have been processed using standard procedures; the radionuclide concentrations being determined using an HPGe ?-ray spectrometer. For molluscs, assuming secular equilibrium, the range of activities of 238U (226Ra), 232Th (228Ra) and 40K were found to be 3.280.35 to 5.340.52, 1.200.21 to 2.440.21 and 1186 to 28114 Bq kg-1 dry weight, respectively. The respective values for crustaceans were 3.020.57 to 4.700.52, 1.380.21 to 2.400.35 and 21611 to 31615 Bq kg-1. The estimated average daily intake of radioactivity from consumption of molluscs are 0.37 Bq kg-1 for 238U (226Ra), 0.16 Bq kg-1 for 232Th (228Ra) and 18 Bq kg-1 for 40K; the respective daily intake values from crustaceans are 0.36 Bq kg-1, 0.16 Bq kg-1 and 23 Bq kg-1. Associated annual committed effective doses from molluscs are estimated to be in the range 21.3 to 34.7 ?Sv for 226Ra, 19.3 to 39.1 ?Sv for 228Ra and 17.0 to 40.4 ?Sv for 40K. For crustaceans, the respective dose ranges are 19.6 to 30.5 ?Sv, 22.0 to 38.4 ?Sv and 31.1 to 45.5 ?Sv, being some several times world average values.

  11. Genomic resource development for shellfish of conservation concern.

    PubMed

    Timmins-Schiffman, Emma B; Friedman, Carolyn S; Metzger, Dave C; White, Samuel J; Roberts, Steven B

    2013-03-01

    Effective conservation of threatened species depends on the ability to assess organism physiology and population demography. To develop genomic resources to better understand the dynamics of two ecologically vulnerable species in the Pacific Northwest of the United States, larval transcriptomes were sequenced for the pinto abalone, Haliotis kamtschatkana kamtschatkana, and the Olympia oyster, Ostrea lurida. Based on comparative species analysis the Ostrea lurida transcriptome (41136 contigs) is relatively complete. These transcriptomes represent the first significant contribution to genomic resources for both species. Genes are described based on biological function with particular attention to those associated with temperature change, oxidative stress and immune function. In addition, transcriptome-derived genetic markers are provided. Together, these resources provide valuable tools for future studies aimed at conservation of Haliotis kamtschatkana kamtschatkana, Ostrea lurida and related species. PMID:23280275

  12. Impact of elevated CO2 on shellfish calcification

    NASA Astrophysics Data System (ADS)

    Gazeau, Frédéric; Quiblier, Christophe; Jansen, Jeroen M.; Gattuso, Jean-Pierre; Middelburg, Jack J.; Heip, Carlo H. R.

    2007-04-01

    Ocean acidification resulting from human emissions of carbon dioxide has already lowered and will further lower surface ocean pH. The consequent decrease in calcium carbonate saturation potentially threatens calcareous marine organisms. Here, we demonstrate that the calcification rates of the edible mussel (Mytilus edulis) and Pacific oyster (Crassostrea gigas) decline linearly with increasing pCO2. Mussel and oyster calcification may decrease by 25 and 10%, respectively, by the end of the century, following the IPCC IS92a scenario (~740 ppmv in 2100). Moreover, mussels dissolve at pCO2 values exceeding a threshold value of ~1800 ppmv. As these two species are important ecosystem engineers in coastal ecosystems and represent a large part of worldwide aquaculture production, the predicted decrease of calcification in response to ocean acidification will probably have an impact on coastal biodiversity and ecosystem functioning as well as potentially lead to significant economic loss.

  13. Water quality and shellfish sanitation. [Patuxent and Choptank River watersheds

    NASA Technical Reports Server (NTRS)

    Eisenberg, M.

    1978-01-01

    The use of remote sensing techniques for collecting bacteriological, physical, and chemical water quality data, locating point and nonpoint sources of pollution, and developing hydrological data was found to be valuable to the Maryland program if it could be produced effectively and rapidly with a minimum amount of ground corroboration.

  14. Allergy-induced preterm labor after the ingestion of shellfish.

    PubMed

    Romero, Roberto; Kusanovic, Juan Pedro; Muñoz, Hernan; Gomez, Ricardo; Lamont, Ronald F; Yeo, Lami

    2010-04-01

    Preterm parturition is a syndrome caused by several mechanisms of disease, including intrauterine infection/inflammation, uteroplacental ischemia, uterine overdistension, cervical disease, maternal/fetal stress, abnormal allogeneic responses, allergic reactions, and unknown insults. An allergic-like mechanism was proposed as a potential etiology for the preterm parturition syndrome, based on the observation that eosinophils were present in the amniotic fluid in a fraction of women with preterm labor and a history of allergy, coupled with the observation that conditioned media from degranulated mast cells (the effector cells of type 1 hypersensitivity) induced contractility of human myometrial strips. This communication describes a case of a pregnant woman who had an allergic reaction and regular uterine contractions after the ingestion of lobster meat, to which she was known to be allergic. Preterm labor subsided after the treatment of antihistamines and steroids. The patient subsequently delivered at term. At follow-up, the child was diagnosed with atopy and asthma, and required frequent use of inhaled corticosteroids and beta-2 adrenergic agents. The immunological basis for preterm labor induced by an allergic-like reaction (hypersensitivity) is reviewed. PMID:19900031

  15. 36 CFR 242.28 - Subsistence taking of shellfish.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... before and 14 days after State open commercial fishing seasons for red king crab, blue king crab, or... apply to subsistence taking of Dungeness crab, king crab, Tanner crab, shrimp, clams, abalone, and other... or buoys attached to subsistence crab pots also must be inscribed with the name or United...

  16. 36 CFR 242.28 - Subsistence taking of shellfish.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... before and 14 days after State open commercial fishing seasons for red king crab, blue king crab, or... to subsistence taking of Dungeness crab, king crab, Tanner crab, shrimp, clams, abalone, and other... or buoys attached to subsistence crab pots also must be inscribed with the name or United...

  17. Recent intervention and detection advances for shellfish-borne norovirus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Human norovirus strains cannot be propagated in the laboratory and current detection methods are based on RNA detection methods, such as RT-PCR. Unfortunately, current RNA-based methods cannot distinguish infectious virions from damaged virions unless the capsid has lost its integrity. In order t...

  18. Tracking responses to the 2010 Deepwater Horizon oil spill using trace elements in molluscan shells and tissues

    NASA Astrophysics Data System (ADS)

    Roopnarine, P. D.; Anderson, L.; Roopnarine, D.; Gillikin, D. P.; Goodwin, D.

    2010-12-01

    Documenting the effects of modern stressors on coastal benthic marine communities requires a combination of baseline historical data and modern dynamic data. E.g., landfall of hydrocarbons from the 2010 Deepwater Horizon rig and well explosion in the Gulf of Mexico is impacting coastal areas long affected by natural seepage, as well as petroleum exploration and development. In Louisiana, exploration in coastal areas that began in the 1920s expanded greatly with the development of the first mobile drilling barge in 1933. In total nearly 50,000 wells have been drilled in the Gulf of Mexico since the 1930s. Given this historical context, we are assessing pathways and rates at which crude oil components from the 2010 spill are incorporated into northern Gulf of Mexico coastal food webs. Sclerochronological techniques are being used to unlock the high-resolution physical and chemical records preserved within mollusc shells. We are analyzing historical specimens collected from the late 19th through late 20th centuries, baseline specimens collected in May 2010 in Louisiana and Alabama before visible hydrocarbons were present, and specimens collected in August 2010 after hydrocarbons made landfall. We are examining changes in life history traits (growth rate, recruitment, mortality, reproduction) of the commercial oyster Crassostrea virginica, and other common, co-occurring molluscs that are primary and secondary consumers in Gulf of Mexico coastal food webs. The taxa include the marsh-dwelling gastropod Littoraria irrorata and mussel Geukensia demissa, and open-water species including the bivalves Ischadium recurvum and Tellina alternata. These consumers range from epifaunal, sessile, filter feeders; to infaunal, mobile, deposit feeders; to epifaunal, mobile, omnivorous grazers. In this way, multiple potential pathways into coastal food webs are being monitored. Because environmental perturbations of many scales are recorded by the accretionary growth of mollusc shells, we can monitor the sub-monthly incorporation of hydrocarbon components into shells, such as trace metals (e.g., V, Ni, Cu and Cr), while simultaneously measuring changes in shell growth rate. We will also measure concentrations of metals in soft tissues from specimens collected since May 2010. Trace metal concentrations will be determined using ICPMS. Annual and sub-annual growth rates will be calculated from ?13C and ?18O profiles derived from ontogentic sampling of the molluscs' shells. The comparisons between historic, baseline and post-landfall specimens will allow us to assess the changing conditions of these species and their food webs as drilling expanded in the Gulf during the 20th century, and therefore distinguish the immediate impact of the Deepwater Horizon spill from these background factors. In this way, we will also trace secondary impacts (not related to fouling by direct contact) of hydrocarbons through trophic levels of the coastal ecosystem.

  19. EDUCATION WORKSHOP FOR THE FLORIDA MEDICAL COMMUNITY ON THE RISKS ASSOCIATED WITH SHELLFISH CONSUMPTION

    EPA Science Inventory

    People whose immune systems are compromised by liver disease, chemotherapy, etc. are at a substantial risk of contracting a fatal infection from the marine bacteria, Vibrio vulnificus to which they could potentially be exposed by eating raw oysters. It has proven difficult to ge...

  20. Harvesting Shellfish: Unit F#2 Grade 4. Project COULD: Career Orientation Utilizing Language Development.

    ERIC Educational Resources Information Center

    Coos County Intermediate Education District, North Bend, OR.

    Project COULD (Career Orientation Utilizing Language Development) was developed as a means of building skills, knowledges, and attitudes on elementary children's previously acquired backgrounds. Children begin to speak the grammar and vocabulary characteristic of the language heard most frequently at home and in the immediate environment. A series