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Sample records for adult fish populations

  1. Genetic correlations between adults and larvae in a marine fish: potential effects of fishery selection on population replenishment

    PubMed Central

    Johnson, Darren W; Christie, Mark R; Moye, Jessica; Hixon, Mark A

    2011-01-01

    Correlated genetic responses have been hypothesized as important components of fishery-induced evolution, although predictive data from wild populations have been difficult to obtain. Here, we demonstrate substantial genetic correlations between a trait often subjected to fishery selection (adult body length) and traits that affect survival of larvae (length and swimming performance) in a wild population of a marine fish (bicolor damselfish, Stegastes partitus). Through both genetic covariance and size-dependent maternal effects, selection on adult size may cause a considerable, correlated response in larval traits. To quantify how variation in larval traits may affect survival, we introduce a flexible method that uses information from selection measurements to account for frequency dependence and estimate the relationship between phenotype and relative survival across a broad range of phenotypic values. Using this method, we synthesize studies of selective mortality on larval size for eight species of fish and show that variation in larval size may result in considerable variation in larval survival. We predict that observed rates of fishery selection on adult marine fishes may substantially reduce larval size and survival. The evolution of smaller larvae in response to fishery selection may therefore have substantial consequences for the viability of fished populations. PMID:25568010

  2. Fishing amplifies forage fish population collapses.

    PubMed

    Essington, Timothy E; Moriarty, Pamela E; Froehlich, Halley E; Hodgson, Emma E; Koehn, Laura E; Oken, Kiva L; Siple, Margaret C; Stawitz, Christine C

    2015-05-26

    Forage fish support the largest fisheries in the world but also play key roles in marine food webs by transferring energy from plankton to upper trophic-level predators, such as large fish, seabirds, and marine mammals. Fishing can, thereby, have far reaching consequences on marine food webs unless safeguards are in place to avoid depleting forage fish to dangerously low levels, where dependent predators are most vulnerable. However, disentangling the contributions of fishing vs. natural processes on population dynamics has been difficult because of the sensitivity of these stocks to environmental conditions. Here, we overcome this difficulty by collating population time series for forage fish populations that account for nearly two-thirds of global catch of forage fish to identify the fingerprint of fisheries on their population dynamics. Forage fish population collapses shared a set of common and unique characteristics: high fishing pressure for several years before collapse, a sharp drop in natural population productivity, and a lagged response to reduce fishing pressure. Lagged response to natural productivity declines can sharply amplify the magnitude of naturally occurring population fluctuations. Finally, we show that the magnitude and frequency of collapses are greater than expected from natural productivity characteristics and therefore, likely attributed to fishing. The durations of collapses, however, were not different from those expected based on natural productivity shifts. A risk-based management scheme that reduces fishing when populations become scarce would protect forage fish and their predators from collapse with little effect on long-term average catches.

  3. Fishing amplifies forage fish population collapses

    PubMed Central

    Essington, Timothy E.; Moriarty, Pamela E.; Froehlich, Halley E.; Hodgson, Emma E.; Koehn, Laura E.; Oken, Kiva L.; Siple, Margaret C.; Stawitz, Christine C.

    2015-01-01

    Forage fish support the largest fisheries in the world but also play key roles in marine food webs by transferring energy from plankton to upper trophic-level predators, such as large fish, seabirds, and marine mammals. Fishing can, thereby, have far reaching consequences on marine food webs unless safeguards are in place to avoid depleting forage fish to dangerously low levels, where dependent predators are most vulnerable. However, disentangling the contributions of fishing vs. natural processes on population dynamics has been difficult because of the sensitivity of these stocks to environmental conditions. Here, we overcome this difficulty by collating population time series for forage fish populations that account for nearly two-thirds of global catch of forage fish to identify the fingerprint of fisheries on their population dynamics. Forage fish population collapses shared a set of common and unique characteristics: high fishing pressure for several years before collapse, a sharp drop in natural population productivity, and a lagged response to reduce fishing pressure. Lagged response to natural productivity declines can sharply amplify the magnitude of naturally occurring population fluctuations. Finally, we show that the magnitude and frequency of collapses are greater than expected from natural productivity characteristics and therefore, likely attributed to fishing. The durations of collapses, however, were not different from those expected based on natural productivity shifts. A risk-based management scheme that reduces fishing when populations become scarce would protect forage fish and their predators from collapse with little effect on long-term average catches. PMID:25848018

  4. Genomic Approaches with Natural Fish Populations

    PubMed Central

    Oleksiak, M. F.

    2011-01-01

    Natural populations versus inbred stocks provide a much richer resource for identifying the effects of nucleotide substitutions because natural populations have greater polymorphism. Additionally, natural populations offer an advantage over most common research organisms because they are subject to natural selection, and analyses of these adaptations can be used to identify biologically important changes. Among fishes, these analyses are enhanced by having a wide diversity of species (> 28,000 species, more than any other group of vertebrates) living in a huge range of environments (from below freezing to > 46° C, in fresh water to salinities > 40 ppt.). Moreover, fishes exhibit many different life history and reproductive strategies and have many different phenotypes and social structures. While fishes provide numerous advantages over other vertebrate models, there is still a dearth of available genomic tools for fishes. Fish make up approximately half of all known vertebrate species, yet less than 0.2% of fish species have significant genomic resources. Nonetheless, genomic approaches with fishes have provided some of the first measures of individual variation in gene expression and insights in to environmental and ecological adaptations. Thus, genomic approaches with natural fish populations have the potential to revolutionize fundamental studies of diverse fish species that offer myriad ecological and evolutionary questions. PMID:20409163

  5. POPULATION DECLINE IN STREAM FISH

    EPA Science Inventory

    Over half of the streams in the Mid-Atlantic Highlands have fish communities that are in fair or poor condition, and the EPA concluded that physical habitat alteration represents the greatest potential stressor across this region. A quantitative method for relating habitat quali...

  6. Stretched to the limit; can a short pelagic larval duration connect adult populations of an Indo-Pacific diadromous fish (Kuhlia rupestris)?

    PubMed

    Feutry, P; Vergnes, A; Broderick, D; Lambourdière, J; Keith, P; Ovenden, J R

    2013-03-01

    Freshwater species on tropical islands face localized extinction and the loss of genetic diversity. Their habitats can be ephemeral due to variability in freshwater run-off and erosion. Even worse, anthropogenic effects on these ecosystems are intense. Most of these species are amphidromous or catadromous (i.e. their life cycle includes a marine larval phase), which buffers them against many of these effects. A long pelagic larval duration (PLD) was thought to be critical to ensure the colonization and persistence in tropical islands, but recent findings indicated that several species with short PLDs are successful in those ecosystems. To test the potential of a short PLD in maintaining genetic connectivity and forestalling extirpation, we studied Kuhlia rupestris, a catadromous fish species with an extensive distribution in the western Pacific and Indian Oceans. Using a combination of molecular genetic markers (13 microsatellite loci and two gene regions from mtDNA) and modelling of larval dispersal, we show that a short PLD constrains genetic connectivity over a wide geographical range. Molecular markers showed that the short PLD did not prevent genetic divergence through evolutionary time and speciation has occurred or is occurring. Modelling of larvae dispersal suggested limited recent connectivity between genetically homogeneous populations across the Coral Sea. However, a short PLD can maintain connectivity on a subocean basin scale. Conservation and management of tropical diadromous species needs to take into account that population connectivity may be more limited than previously suspected in those species. PMID:23294379

  7. Coral reef fish populations can persist without immigration.

    PubMed

    Salles, Océane C; Maynard, Jeffrey A; Joannides, Marc; Barbu, Corentin M; Saenz-Agudelo, Pablo; Almany, Glenn R; Berumen, Michael L; Thorrold, Simon R; Jones, Geoffrey P; Planes, Serge

    2015-11-22

    Determining the conditions under which populations may persist requires accurate estimates of demographic parameters, including immigration, local reproductive success, and mortality rates. In marine populations, empirical estimates of these parameters are rare, due at least in part to the pelagic dispersal stage common to most marine organisms. Here, we evaluate population persistence and turnover for a population of orange clownfish, Amphiprion percula, at Kimbe Island in Papua New Guinea. All fish in the population were sampled and genotyped on five occasions at 2-year intervals spanning eight years. The genetic data enabled estimates of reproductive success retained in the same population (reproductive success to self-recruitment), reproductive success exported to other subpopulations (reproductive success to local connectivity), and immigration and mortality rates of sub-adults and adults. Approximately 50% of the recruits were assigned to parents from the Kimbe Island population and this was stable through the sampling period. Stability in the proportion of local and immigrant settlers is likely due to: low annual mortality rates and stable egg production rates, and the short larval stages and sensory capacities of reef fish larvae. Biannual mortality rates ranged from 0.09 to 0.55 and varied significantly spatially. We used these data to parametrize a model that estimated the probability of the Kimbe Island population persisting in the absence of immigration. The Kimbe Island population was found to persist without significant immigration. Model results suggest the island population persists because the largest of the subpopulations are maintained due to having low mortality and high self-recruitment rates. Our results enable managers to appropriately target and scale actions to maximize persistence likelihood as disturbance frequencies increase. PMID:26582017

  8. Coral reef fish populations can persist without immigration.

    PubMed

    Salles, Océane C; Maynard, Jeffrey A; Joannides, Marc; Barbu, Corentin M; Saenz-Agudelo, Pablo; Almany, Glenn R; Berumen, Michael L; Thorrold, Simon R; Jones, Geoffrey P; Planes, Serge

    2015-11-22

    Determining the conditions under which populations may persist requires accurate estimates of demographic parameters, including immigration, local reproductive success, and mortality rates. In marine populations, empirical estimates of these parameters are rare, due at least in part to the pelagic dispersal stage common to most marine organisms. Here, we evaluate population persistence and turnover for a population of orange clownfish, Amphiprion percula, at Kimbe Island in Papua New Guinea. All fish in the population were sampled and genotyped on five occasions at 2-year intervals spanning eight years. The genetic data enabled estimates of reproductive success retained in the same population (reproductive success to self-recruitment), reproductive success exported to other subpopulations (reproductive success to local connectivity), and immigration and mortality rates of sub-adults and adults. Approximately 50% of the recruits were assigned to parents from the Kimbe Island population and this was stable through the sampling period. Stability in the proportion of local and immigrant settlers is likely due to: low annual mortality rates and stable egg production rates, and the short larval stages and sensory capacities of reef fish larvae. Biannual mortality rates ranged from 0.09 to 0.55 and varied significantly spatially. We used these data to parametrize a model that estimated the probability of the Kimbe Island population persisting in the absence of immigration. The Kimbe Island population was found to persist without significant immigration. Model results suggest the island population persists because the largest of the subpopulations are maintained due to having low mortality and high self-recruitment rates. Our results enable managers to appropriately target and scale actions to maximize persistence likelihood as disturbance frequencies increase.

  9. Population Viability Analysis of Riverine Fishes

    SciTech Connect

    Bates, P.; Chandler, J.; Jager, H.I.; Lepla, K.; Van Winkle, W.

    1999-04-12

    Many utilities face conflkts between two goals: cost-efficient hydropower generation and protecting riverine fishes. Research to develop ecological simulation tools that can evaluate alternative mitigation strategies in terms of their benefits to fish populations is vital to informed decision-making. In this paper, we describe our approach to population viability analysis of riverine fishes in general and Snake River white sturgeon in particular. We are finding that the individual-based modeling approach used in previous in-stream flow applications is well suited to addressing questions about the viability of species of concern for several reasons. Chief among these are: (1) the abiIity to represent the effects of individual variation in life history characteristics on predicted population viabili~, (2) the flexibili~ needed to quanti~ the ecological benefits of alternative flow management options by representing spatial and temporal variation in flow and temperaturty and (3) the flexibility needed to quantifi the ecological benefits of non-flow related manipulations (i.e., passage, screening and hatchery supplementation).

  10. Replenishment of fish populations is threatened by ocean acidification

    PubMed Central

    Munday, Philip L.; Dixson, Danielle L.; McCormick, Mark I.; Meekan, Mark; Ferrari, Maud C. O.; Chivers, Douglas P.

    2010-01-01

    There is increasing concern that ocean acidification, caused by the uptake of additional CO2 at the ocean surface, could affect the functioning of marine ecosystems; however, the mechanisms by which population declines will occur have not been identified, especially for noncalcifying species such as fishes. Here, we use a combination of laboratory and field-based experiments to show that levels of dissolved CO2 predicted to occur in the ocean this century alter the behavior of larval fish and dramatically decrease their survival during recruitment to adult populations. Altered behavior of larvae was detected at 700 ppm CO2, with many individuals becoming attracted to the smell of predators. At 850 ppm CO2, the ability to sense predators was completely impaired. Larvae exposed to elevated CO2 were more active and exhibited riskier behavior in natural coral-reef habitat. As a result, they had 5–9 times higher mortality from predation than current-day controls, with mortality increasing with CO2 concentration. Our results show that additional CO2 absorbed into the ocean will reduce recruitment success and have far-reaching consequences for the sustainability of fish populations. PMID:20615968

  11. Intravenous fish oil in adult intensive care unit patients.

    PubMed

    Heller, Axel R

    2015-01-01

    Omega-3 fatty acids contained in fish oils have shown efficacy in the treatment of chronic and acute inflammatory diseases due to their pleiotropic effects on inflammatory cell signalling pathways. In a variety of experimental and clinical studies, omega-3 fatty acids attenuated hyperinflammatory conditions and induced faster recovery. This chapter will shed light on the effects of intravenous fish oil in adult intensive care unit (ICU) patients and will discuss clinical data and recent meta-analyses on the topic. While significant beneficial effects on infection rates and the lengths of ICU and hospital stays have concordantly been identified in three recent meta-analyses on non-ICU surgical patients, the level of evidence is not so clear for critically ill patients. Three meta-analyses published in 2012 or 2013 explored data on the ICU population. Although the present data suggest the consideration of enteral nutrition enriched with fish oil, borage oil and antioxidants in mild to severe acute respiratory distress syndrome, only one of the three meta-analyses found a trend (p = 0.08) of lower mortality in ICU patients receiving intravenous omega-3 fatty acids. Two of the meta-analyses indicated a significantly shorter hospital stay (5.17-9.49 days), and one meta-analysis found a significant reduction in ICU days (1.92). As a result of these effects, cost savings were postulated. Unlike in surgical patients, the effects of fish oil on infection rates were not found to be statistically significant in ICU patients, and dose-effect relationships were not established for any cohort. Thus, obvious positive secondary outcome effects with intravenous fish oil have not yet been shown to transfer to lower mortality in critically ill patients. There is a need for adequately powered, well-planned and well-conducted randomized trials to give clear recommendations on the individual utility and dosage of intravenous omega-3 fatty acids in critical illness. PMID:25471809

  12. Short winters threaten temperate fish populations

    PubMed Central

    Farmer, Troy M.; Marschall, Elizabeth A.; Dabrowski, Konrad; Ludsin, Stuart A.

    2015-01-01

    Although climate warming is expected to benefit temperate ectotherms by lengthening the summer growing season, declines in reproductive success following short, warm winters may counter such positive effects. Here we present long-term (1973–2010) field patterns for Lake Erie yellow perch, Perca flavescens, which show that failed annual recruitment events followed short, warm winters. Subsequent laboratory experimentation and field investigations revealed how reduced reproductive success following short, warm winters underlie these observed field patterns. Following short winters, females spawn at warmer temperatures and produce smaller eggs that both hatch at lower rates and produce smaller larvae than females exposed to long winters. Our research suggests that continued climate warming can lead to unanticipated, negative effects on temperate fish populations. PMID:26173734

  13. Assessing changes in amphibian population dynamics following experimental manipulations of introduced fish.

    PubMed

    Pope, Karen L

    2008-12-01

    Sport-fish introductions are now recognized as an important cause of amphibian decline, but few researchers have quantified the demographic responses of amphibians to current options in fisheries management designed to minimize effects on sensitive amphibians. Demographic analyses with mark-recapture data allow researchers to assess the relative importance of survival, local recruitment, and migration to changes in population densities. I conducted a 4-year, replicated whole-lake experiment in the Klamath Mountains of northern California (U.S.A.) to quantify changes in population density, survival, population growth rate, and recruitment of the Cascades frog (Rana cascadae) in response to manipulations of non-native fish populations. I compared responses of the frogs in lakes where fish were removed, in lakes in their naturally fish-free state, and in lakes where fish remained that were either stocked annually or no longer being stocked. Within 3 years of fish removals from 3 lakes, frog densities increased by a factor of 13.6. The survival of young adult frogs increased from 59% to 94%, and realized population growth and recruitment rates at the fish-removal lakes were more than twice as high as the rates for fish-free reference lakes and lakes that contained fish. Population growth in the fish-removal lakes was likely due to better on-site recruitment of frogs to later life stages rather than increased immigration. The effects on R. cascadae of suspending stocking were ambiguous and suggested no direct benefit to amphibians. With amphibians declining worldwide, these results show that active restoration can slow or reverse the decline of species affected by fish stocking within a short time frame.

  14. Kelp forest fish populations in marine reserves and adjacent exploited areas of central California

    USGS Publications Warehouse

    Paddack, M.J.; Estes, J.A.

    2000-01-01

    Population structure (density and size distribution) of 10 species of epibenthic kelp forest fishes was compared between three marine reserves and adjacent exploited areas in central California. We also contrasted substrate relief, algal turf cover, and kelp population density among these areas. Densities of fishes were 12-35% greater within the reserves, but this difference was not statistically) significant. Habitat features explained only 4% of the variation in fish density and did not vary consistently between reserves and nonreserves. The average length of rockfish (genus Sebastes) was significantly greater in two of the three reserve sites, as was the proportion of larger fish. Population density and size differences combined to produce substantially greater biomass and, therefore, greater reproductive potential per unit of area within the reserves. The magnitude of these effects seems to be influenced by the reserve's age. Our findings demonstrate that current levels of fishing pressure influence kelp forest rockfish populations and suggest that this effect is widespread in central California. Existing marine reserves in central California kelp forests may help sustain exploited populations both through adult emigration and larval pool augmentation. The magnitude of these effects remains uncertain, however, because the spatial scale of both larval and adult dispersal relative to the size of existing reserves is unknown.

  15. Spatial structuring within a reservoir fish population: implications for management

    USGS Publications Warehouse

    Stewart, David R.; Long, James M.; Shoup, Daniel E.

    2014-01-01

    Spatial structuring in reservoir fish populations can exist because of environmental gradients, species-specific behaviour, or even localised fishing effort. The present study investigated whether white crappie exhibited evidence of improved population structure where the northern more productive half of a lake is closed to fishing to provide waterfowl hunting opportunities. Population response to angling was modelled for each substock of white crappie (north (protected) and south (unprotected) areas), the entire lake (single-stock model) and by combining simulations of the two independent substock models (additive model). White crappie in the protected area were more abundant, consisting of larger, older individuals, and exhibited a lower total annual mortality rate than in the unprotected area. Population modelling found that fishing mortality rates between 0.1 and 0.3 resulted in sustainable populations (spawning potential ratios (SPR) >0.30). The population in the unprotected area appeared to be more resilient (SPR > 0.30) at the higher fishing intensities (0.35–0.55). Considered additively, the whole-lake fishery appeared more resilient than when modelled as a single-panmictic stock. These results provided evidence of spatial structuring in reservoir fish populations, and we recommend model assessments used to guide management decisions should consider those spatial differences in other populations where they exist.

  16. Recovery of a wild fish population from whole-lake additions of a synthetic estrogen.

    PubMed

    Blanchfield, Paul J; Kidd, Karen A; Docker, Margaret F; Palace, Vince P; Park, Brad J; Postma, Lianne D

    2015-03-01

    Despite widespread recognition that municipal wastewaters contain natural and synthetic estrogens, which interfere with development and reproduction of fishes in freshwaters worldwide, there are limited data on the extent to which natural populations of fish can recover from exposure to these compounds. We conducted whole-lake additions of an active component of the birth control pill (17α-ethynylestradiol; EE2) that resulted in the collapse of the fathead minnow (Pimephales promelas) population. Here we quantify physiological, population, and genetic characteristics of this population over the 7 years after EE2 additions stopped to determine if complete recovery was possible. By 3 years post-treatment, whole-body vitellogenin concentrations in male fathead minnow had returned to baseline, and testicular abnormalities were absent. In the spring of the fourth year, adult size-frequency distribution and abundance had returned to pretreatment levels. Microsatellite analyses clearly showed that postrecovery fish were descendants of the original EE2-treated population. Results from this whole-lake experiment demonstrate that fish can recover from EE2 exposure at the biochemical through population levels, although the timelines to do so are long for multigenerational exposures. These results suggest that wastewater treatment facilities that reduce discharges of estrogens and their mimics can improve the health of resident fish populations in their receiving environments.

  17. Recovery of a wild fish population from whole-lake additions of a synthetic estrogen.

    PubMed

    Blanchfield, Paul J; Kidd, Karen A; Docker, Margaret F; Palace, Vince P; Park, Brad J; Postma, Lianne D

    2015-03-01

    Despite widespread recognition that municipal wastewaters contain natural and synthetic estrogens, which interfere with development and reproduction of fishes in freshwaters worldwide, there are limited data on the extent to which natural populations of fish can recover from exposure to these compounds. We conducted whole-lake additions of an active component of the birth control pill (17α-ethynylestradiol; EE2) that resulted in the collapse of the fathead minnow (Pimephales promelas) population. Here we quantify physiological, population, and genetic characteristics of this population over the 7 years after EE2 additions stopped to determine if complete recovery was possible. By 3 years post-treatment, whole-body vitellogenin concentrations in male fathead minnow had returned to baseline, and testicular abnormalities were absent. In the spring of the fourth year, adult size-frequency distribution and abundance had returned to pretreatment levels. Microsatellite analyses clearly showed that postrecovery fish were descendants of the original EE2-treated population. Results from this whole-lake experiment demonstrate that fish can recover from EE2 exposure at the biochemical through population levels, although the timelines to do so are long for multigenerational exposures. These results suggest that wastewater treatment facilities that reduce discharges of estrogens and their mimics can improve the health of resident fish populations in their receiving environments. PMID:25658019

  18. General effects of climate change on Arctic fishes and fish populations.

    PubMed

    Reist, James D; Wrona, Frederick J; Prowse, Terry D; Power, Michael; Dempson, J Brian; Beamish, Richard J; King, Jacquelynne R; Carmichael, Theresa J; Sawatzky, Chantelle D

    2006-11-01

    Projected shifts in climate forcing variables such as temperature and precipitation are of great relevance to arctic freshwater ecosystems and biota. These will result in many direct and indirect effects upon the ecosystems and fish present therein. Shifts projected for fish populations will range from positive to negative in overall effect, differ among species and also among populations within species depending upon their biology and tolerances, and will be integrated by the fish within their local aquascapes. This results in a wide range of future possibilities for arctic freshwater and diadromous fishes. Owing to a dearth of basic knowledge regarding fish biology and habitat interactions in the north, complicated by scaling issues and uncertainty in future climate projections, only qualitative scenarios can be developed in most cases. This limits preparedness to meet challenges of climate change in the Arctic with respect to fish and fisheries.

  19. Longitudinal associations between fish consumption and depression in young adults.

    PubMed

    Smith, Kylie J; Sanderson, Kristy; McNaughton, Sarah A; Gall, Seana L; Dwyer, Terry; Venn, Alison J

    2014-05-15

    Few studies have examined longitudinal associations between fish consumption and depression; none have defined depression using a diagnostic tool. We investigated whether fish consumption was associated with fewer new depression episodes in a national study of Australian adults. In 2004-2006, 1,386 adults aged 26-36 years (38% males) completed a 127-item (9 fish items) food frequency questionnaire. Fish intake was examined continuously (times/week) and dichotomously (reference group: <2 times/week). During 2009-2011, the lifetime version of the Composite International Diagnostic Interview was administered by telephone. New episodes of major depression/dysthymic disorder (since baseline) were defined using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. During follow-up, 160 (18.8%) women and 70 (13.1%) men experienced depression. For women, each additional weekly serving of fish consumed at baseline decreased the risk of having a new depressive episode by 6% (adjusted relative risk = 0.94, 95% confidence interval: 0.87, 1.01). Women who ate fish ≥2 times/week at baseline had a 25% lower risk of depression during follow-up than those who ate fish <2 times/week (adjusted relative risk = 0.75, 95% confidence interval: 0.57, 0.99). Reverse causation was also suggested but appeared to be restricted to persons with recent depression. Fish consumption was not associated with depression in men. These findings provide further evidence that fish consumption may be beneficial for women's mental health.

  20. Fish population dynamics in a seasonally varying wetland

    USGS Publications Warehouse

    DeAngelis, Donald L.; Trexler, Joel C.; Cosner, Chris; Obaza, Adam; Jopp, Fred

    2010-01-01

    Small fishes in seasonally flooded environments such as the Everglades are capable of spreading into newly flooded areas and building up substantial biomass. Passive drift cannot account for the rapidity of observed population expansions. To test the reaction-diffusion mechanism for spread of the fish, we estimated their diffusion coefficient and applied a reaction-diffusion model. This mechanism was also too weak to account for the spatial dynamics. Two other hypotheses were tested through modeling. The first--the 'refuge mechanism--hypothesizes that small remnant populations of small fishes survive the dry season in small permanent bodies of water (refugia), sites where the water level is otherwise below the surface. The second mechanism, which we call the 'dynamic ideal free distribution mechanism' is that consumption by the fish creates a prey density gradient and that fish taxis along this gradient can lead to rapid population expansion in space. We examined the two alternatives and concluded that although refugia may play an important role in recolonization by the fish population during reflooding, only the second, taxis in the direction of the flooding front, seems capable of matching empirical observations. This study has important implications for management of wetlands, as fish biomass is an essential support of higher trophic levels.

  1. Adult height, nutrition, and population health.

    PubMed

    Perkins, Jessica M; Subramanian, S V; Davey Smith, George; Özaltin, Emre

    2016-03-01

    In this review, the potential causes and consequences of adult height, a measure of cumulative net nutrition, in modern populations are summarized. The mechanisms linking adult height and health are examined, with a focus on the role of potential confounders. Evidence across studies indicates that short adult height (reflecting growth retardation) in low- and middle-income countries is driven by environmental conditions, especially net nutrition during early years. Some of the associations of height with health and social outcomes potentially reflect the association between these environmental factors and such outcomes. These conditions are manifested in the substantial differences in adult height that exist between and within countries and over time. This review suggests that adult height is a useful marker of variation in cumulative net nutrition, biological deprivation, and standard of living between and within populations and should be routinely measured. Linkages between adult height and health, within and across generations, suggest that adult height may be a potential tool for monitoring health conditions and that programs focused on offspring outcomes may consider maternal height as a potentially important influence.

  2. May organic pollutants affect fish populations in the North Sea?

    PubMed

    Hylland, Ketil; Beyer, Jonny; Berntssen, Marc; Klungsøyr, Jarle; Lang, Thomas; Balk, Lennart

    2006-01-01

    The North Sea is a highly productive area with large fish populations that have been extensively harvested over the past century. North Sea fisheries remain important to the surrounding countries despite declining fish stocks over the past decades. The main reason for declining fish stocks is nearly certainly overfishing, but other environmental pressures also affect fish populations, such as eutrophication, climate change, and exposure to metals and organic pollutants, including polyaromatic hydrocarbons (PAHs), alkylphenols, and organochlorine compounds. There are three main sources of organic pollutants in the North Sea: atmospheric, land-based sources, and inputs from offshore gas and oil installations. All three sources contribute to elevated concentrations of organic pollutants in the North Sea compared to the Norwegian Sea. There is evidence that chlorinated organic contaminants were present in sufficiently high concentrations in the southern North Sea two decades ago, to alter embryonal development in fish. The results from extensive, long-term monitoring programs show that some diseases decreased whereas other increased in the southern North Sea and that, among other factors, contaminants may play a role in the temporal changes recorded in disease prevalence. Recent studies demonstrated that components in offshore effluents may affect fish reproduction and that tissues of fish near oil rigs are structurally different to tissues of fish from reference areas. Data on effluents from offshore activities have recently become available through an international workshop (BECPELAG) and follow-up studies.

  3. [New view on the population genetic structure of marine fish].

    PubMed

    Salmenkova, E A

    2011-11-01

    The view on homogeneous population genetic structure in many marine fish with high mobility has changed significantly during the last ten years. Molecular genetic population studies over the whole ranges of such species as Atlantic herring and Atlantic cod showed a complex picture of spatial differentiation both on the macrogeographic and, in many areas, on the microgeographic scale, although the differentiation for neutral molecular markers was low. It was established that the migration activity of such fish is constrained in many areas of the species range by hydrological and physicochemical transition zones (environmental gradients), as well as gyres in the spawning regions. Natal homing was recorded in a number of marine fish species. Existing in marine fish constraints of gene migration and a very high variance of reproductive success determine a significantly smaller proportion of effective reproductive size of their populations in the total population size, which generates more complex abundance dynamics than assumed earlier. The various constraints on gene migration and natal homing in marine fish promote the formation of local adaptations at ecologically important phenotypic traits. Effects of selection underlying adaptations are actively investigated in marine fish on the genomic level, using approaches of population genomics. The knowledge of adaptive intraspecific structure enables understanding the ecological and evolutionary processes, that influence biodiversity and providing spatial frames for conservation of genetic resources under commercial exploitation. Contemporary views on the population genetic and adaptive structures or biocomplexity in marine fish support and develop the main principles of the conception of systemic organization of the species and its regional populations, which were advanced by Yu.P. Altukhov and Yu.G. Rychkov.

  4. Comparative Analysis of State Fish Consumption Advisories Targeting Sensitive Populations

    PubMed Central

    Scherer, Alison C.; Tsuchiya, Ami; Younglove, Lisa R.; Burbacher, Thomas M.; Faustman, Elaine M.

    2008-01-01

    Objective Fish consumption advisories are issued to warn the public of possible toxicological threats from consuming certain fish species. Although developing fetuses and children are particularly susceptible to toxicants in fish, fish also contain valuable nutrients. Hence, formulating advice for sensitive populations poses challenges. We conducted a comparative analysis of advisory Web sites issued by states to assess health messages that sensitive populations might access. Data sources We evaluated state advisories accessed via the National Listing of Fish Advisories issued by the U.S. Environmental Protection Agency. Data extraction We created criteria to evaluate advisory attributes such as risk and benefit message clarity. Data synthesis All 48 state advisories issued at the time of this analysis targeted children, 90% (43) targeted pregnant women, and 58% (28) targeted women of childbearing age. Only six advisories addressed single contaminants, while the remainder based advice on 2–12 contaminants. Results revealed that advisories associated a dozen contaminants with specific adverse health effects. Beneficial health effects of any kind were specifically associated only with omega-3 fatty acids found in fish. Conclusions These findings highlight the complexity of assessing and communicating information about multiple contaminant exposure from fish consumption. Communication regarding potential health benefits conferred by specific fish nutrients was minimal and focused primarily on omega-3 fatty acids. This overview suggests some lessons learned and highlights a lack of both clarity and consistency in providing the breadth of information that sensitive populations such as pregnant women need to make public health decisions about fish consumption during pregnancy. PMID:19079708

  5. Oily Fish Intake and Cognitive Performance in Community-Dwelling Older Adults: The Atahualpa Project.

    PubMed

    Del Brutto, Oscar H; Mera, Robertino M; Gillman, Jennifer; Zambrano, Mauricio; Ha, Jung-eun

    2016-02-01

    Due to their high content of omega-3 polyunsaturated fatty acids, oily fish consumption is likely associated with a better cognitive performance. However, information on this association is controversial, with some studies showing a positive effect while others showing no association. We aimed to assess the effects of oily fish consumption on cognitive performance in a population of frequent fish consumers living in rural coastal Ecuador. Atahualpa residents aged ≥60 years were identified during a door-to-door survey and evaluated by the use of the Montreal Cognitive Assessment (MoCA). Oily fish servings per week were calculated in all participants. We estimated whether fish intake correlated with MoCA scores in generalized multivariate linear models adjusted for demographics, cardiovascular risk factors, edentulism and symptoms of depression. Out of 330 eligible persons, 307 (93%) were enrolled. Mean MoCA scores were 19 ± 4.8 points, and mean oily fish consumption was 8.6 ± 5.3 servings per week. In multivariate analyses, MoCA scores were related to fish servings (β 0.097, 95% CI 0.005-0.188, p = 0.038). Locally weighted scatterplot smoothing showed an inflection point in the total MoCA score curve at four fish servings per week. However, predictive margins of the MoCA score were similar across groups below and above this point, suggesting a direct linear relationship between oily fish intake and cognitive performance. Simple preventive measures, such as modifying dietary habits might be of value to reduce the rate of cognitive decline in community-dwelling older adults living in underserved populations.

  6. Toxic materials, fishing, and environmental variation: simulated effects on striped bass population trends

    SciTech Connect

    Goodyear, C.P.

    1985-01-01

    Decreased survival of larval striped bass Morone saxatilis resulting from toxic chemicals in the environment and decreased survival of adults caused by fishing both are suspected as agents contributing to the decline in the Chesapeake Bay stock since the mid-1970s. The relative power of each type of mortality to cause population declines was evaluated with simulation techniques. Equivalent levels of added mortality induced qualitatively identical and quantitatively similar trends in population simulations for all conditions examined except if strong density-dependent mortality preceded the contaminant toxicity. In this case the contaminant effect caused a greater reduction in yield, but the population did not tend toward extinction. The results indicate that the observed downward trend in the Chesapeake Bay population can be halted or reversed by a reduction in fishing mortality, even if contaminant toxicity is the proximate cause for the decline. 28 references, 1 figure, 1 table.

  7. Methylmercury in populations eating large quantities of marine fish

    SciTech Connect

    Turner, M.D.; Marsh, D.O.; Smith, J.C.; Inglis, J.B.; Clarkson, T.W.; Rubio, C.E.; Chiriboga, J.; Chiriboga, C.C.

    1980-11-01

    A Peruvian population was identified that was chronically exposed to methylmercury from the longterm consumption of ocean fish. The weekly fish intake averaged 10.1 kg per average family of 6.2 persons. Blood methylmercury concentrations ranged from 11 to 275 ng/ml, with a mean of 82 ng/ml. Paresthesias were reported by 29.5% of the population. In contrast, a nearby control population had a mean weekly fish consumption of 1.9 kg per average family of 6.4 persons. Their blood methylmercury levels were 3.3-25.1 ng/ml, with a mean of 9.9 ng/ml. Paresthesias were reported by 49.5% of this control group. No individual was identified with symptoms or signs that could be attributed to methylmercury intoxication.

  8. Frequency of Fish Intake and Diabetes among Adult Indians

    PubMed Central

    Agrawal, Sutapa; Millett, Christopher; Subramanian, S. V.; Ebrahim, Shah

    2014-01-01

    Objectives: Recent studies have shown that the choice of foods plays a role in diabetes prevention. However, little empirical evidence on this association exists in developing countries. We aimed to examine the association between frequency of fish intake and self-reported diabetes status among adult men and women in India. Methods: Analysis of cross-sectional data from participants in India's third National Family Health Survey conducted during 2005–2006 was performed. Associations between fish intake, determined by frequency of consumption (daily, weekly, occasionally, and never), and self-reported diabetes were estimated using multivariable-adjusted models in 99,574 women, 56,742 men, and 39,257 couples aged 20–49 years after adjusting for frequency of consumption of other food items, body mass index (BMI) status, tobacco smoking, alcohol drinking, watching television, age, education, living standard of the household, and place of residence. Results: After adjustment for other dietary, lifestyle, and socioeconomic and demographic characteristics, odds of diabetes were 2 times higher (odds ratio [OR]: 2.02; 95% confidence interval [CI], 1.59–2.57; p < 0.0001) among those who reported consuming fish daily compared to those who never consumed fish. Weekly fish intake was also associated with a higher odds of having diabetes (OR: 1.55; 95% CI, 1.25–1.93; p < 0.0001). The adjusted effect of daily fish intake on diabetes was greater among men (OR: 2.46; 95% CI, 1.66–3.65) than among women (OR: 1.72; 95% CI, 1.26–2.33). In cross-spousal sensitivity analysis, the odds of a husband having diabetes was also associated with wife's daily/weekly consumption of fish (OR: 1.36; 95% CI, 0.92–2.01) and the odds of a wife having diabetes was also associated with husband's daily/weekly consumption of fish (OR: 1.21; 95% CI, 0.87–1.68). Conclusions: In a large nationally representative sample of adult men and women in India, daily or weekly fish intake was

  9. Multimodel robust observer for an uncertain fish population model.

    PubMed

    Ait Kaddour, Achraf; Benjelloun, Khalid; Elalami, Noureddine; El Mazoudi, El Houssine

    2014-10-01

    In this paper, a new method is proposed to design an observer for a nonlinear and uncertain system describing a continuous stage structured model of a harvested fish population. The aim is to get an estimation of the biomass of fishes by stage class. In the studied model the fishing effort is considered as a control term, the stage classes as states and the quantity of captured fish as a measured output. A Takagi-Sugeno multimodel first represents the uncertain non-linear model. Next, we develop a technique for designing a multimodel observer corresponding to this system, which attenuates the effect of modelling uncertainties and measurement noise on the state estimation. The design conditions are given in linear matrix inequalities (LMIs) terms that can be solved efficiently using existing numerical tools. The validity of the proposed method is illustrated by the simulation results.

  10. Evaluation of general response patterns as a diagnostic tool to determining contaminant impacts on fish populations

    SciTech Connect

    Jaworska, J.S.; Barnthouse, L.W.; Rose, K.A.

    1995-12-31

    Five General Response Patterns by fish populations exposed to stress were hypothesized by P. Colby and K. Munkittrick and D. Dixon. The authors used an individual based model of walleye and yellow perch configured for Oneida Lake, NY to test the generality of these patterns. They compared the yellow perch population responses in mean age, size at age, fraction mature at age, individual fecundity and density under 5 stress conditions. The stresses imposed were: (1) adults mortality; (2) eggs mortality (3) metabolic impacts on juveniles; (4) indirect effects from predator level -- increased predator mortality; (5) indirect effects form prey level -- reduced carrying capacity. Modeled yellow perch responses different from the responses hypothesized by Colby/Munkittrick and Dixon. Their analysis shows that the strength of predator-prey coupling must be considered when using patterns of growth, mortality and reproduction to infer the identity of stressors influencing fish populations.

  11. Population size and genome size in fishes: a closer look.

    PubMed

    Gregory, T Ryan; Witt, Jonathan D S

    2008-04-01

    The several thousand-fold range in genome size among animals has remained a subject of active research and debate for more than half a century, but no satisfactory explanation has yet been provided. Many one-dimensional models have been postulated, but so far none has been successful in accounting for observed patterns in genome size diversity. The recent model based on differences in effective population size appeared to gain empirical support with a study of genome size and inferred effective population size in fishes, but there were several questionable aspects of the analysis. First, it was based on an assumption that microsatellite heterozygosity indicates long-term effective population size, whereas in actuality these markers evolve quickly and are sensitive to demographic events. Second, it included both ancient polyploids and non-polyploids, the former of which did not gain their current genome sizes through the accumulation of slightly deleterious mutations as required in the model. Third, the analysis neglected the tremendous influence that Pleistocene glaciation bottlenecks had on heterozygosities in freshwater (and far less so, marine) fishes. In sum, it is apparent that genomes reached their current sizes in most fishes long before contemporary microsatellite heterozygosities were shaped, and that ancient polyploidy rather than the accumulation of mildly deleterious transposon insertions in small populations is the dominant factor that has influenced the large end of the range of genome sizes among fishes.

  12. Effects of fire on fish populations: Landscape perspectives on persistance of native fishes and nonnative fish invasions

    USGS Publications Warehouse

    Dunham, J.B.; Young, M.; Gresswell, Robert E.; Rieman, B.

    2003-01-01

    Our limited understanding of the short and long-term effects of fire on fish contributes to considerable uncertainty in assessments of the risks and benefits of fire management alternatives. A primary concern among the many potential effects of fire is the effects of fire and fire management on persistence of native fish populations. Limited evidence suggests vulnerability of fish to fire is contingent upon the quality of affected habitats, the amount and distribution of habitat (habitat fragmentation), and habitat specificity of the species in question. Species with narrow habitat requirements in highly degraded and fragmented systems are likely to be most vulnerable to fire and fire-related disturbance. In addition to effects of fire on native fish, there are growing concerns about the effects of fire on nonnative fish invasions. The role of fire in facilitating invasions by nonnative fishes is unknown, but experience with other species suggests some forms of disturbance associated with fire may facilitate invasion. Management efforts to promote persistence of fishes in fire-prone landscapes can take the form of four basic alternatives: (1) pre-fire management; (2) post-fire management; (3) managing fire itself (e.g. fire fighting); and (4) monitoring and adaptive management. Among these alternatives, pre-fire management is likely to be most effective. Effective pre-fire management activities will address factors that may render fish populations more vulnerable to the effects of fire (e.g. habitat degradation, fragmentation, and nonnative species). Post-fire management is also potentially important, but suffers from being a reactive approach that may not address threats in time to avert them. Managing fire itself can be important in some contexts, but negative consequences for fish populations are possible (e.g. toxicity of fire fighting chemicals to fish). Monitoring and adaptive management can provide important new information for evaluating alternatives, but

  13. Fish Intake Is Associated with Slower Cognitive Decline in Chinese Older Adults123

    PubMed Central

    Qin, Bo; Plassman, Brenda L.; Edwards, Lloyd J.; Popkin, Barry M.; Adair, Linda S.; Mendez, Michelle A.

    2014-01-01

    Modifiable lifestyle changes, including dietary changes, could translate into a great reduction in the global burden of cognitive impairment and dementia. Few studies evaluated the benefits of fish intake for delaying cognitive decline, and no studies were conducted in a Chinese population, which may differ with respect to types, amounts, and correlates of fish consumption compared with Western populations. We hypothesized that higher consumption of fish would predict slower decline in cognitive function, independent of a wide range of potential confounders. This prospective cohort study comprised 1566 community-dwelling adults aged ≥55 y who completed a cognitive screening test at ≥2 waves of the China Health and Nutrition Survey in 1997, 2000, or 2004, with a mean follow-up of 5.3 y [age at entry (mean ± SD): 63 ± 6 y]. Diet was measured by 3-d 24-h recalls at baseline. Outcomes included repeated measures of global cognitive scores (baseline mean ± SD: 19 ± 6 points), composite cognitive Z-scores (standardized units), and standardized verbal memory scores (standardized units). Multivariable-adjusted linear mixed-effects models were used to evaluate the relation of fish intake with changes in cognitive scores. Age was found to significantly modify the association between fish consumption and cognitive change (P = 0.007). Among adults aged ≥65 y, compared with individuals who consumed <1 serving/wk (i.e., 100 g) fish, the mean annual rate of global cognitive decline was reduced by 0.35 point (95% CI: 0.13, 0.58) among those consuming ≥1 serving/wk, equivalent to the disparity associated with 1.6 y of age. Fish consumption was also associated with a slower decline in composite and verbal memory scores. No associations were observed among adults aged 55–64 y. Our findings suggest a potential role of fish consumption as a modifiable dietary factor to reduce the rate of cognitive decline in later life. PMID:25080536

  14. Empowerment of Fisher Women of Siluvaipatti Fishing Village of Tuticorin, Southeast Coast of India through Adult Education and ICT Training

    ERIC Educational Resources Information Center

    Patterson, Jamila; Linden, Eva; Bierbrier, Christin; Lofgren, Inger; Wilhelmsson, Dan; Edward, J. K. Patterson

    2008-01-01

    This paper focuses on adult education and information and communication technologies (ICT) training to fisherwomen of Siluvaipatti fishing village in Tuticorin district of Tamil Nadu State, southeastern India. The total families in this village are 209 with population 899 (Male: 442; Female: 457). The education level is generally good in…

  15. Effects of human population density and proximity to markets on coral reef fishes vulnerable to extinction by fishing.

    PubMed

    Brewer, T D; Cinner, J E; Green, A; Pressey, R L

    2013-06-01

    Coral reef fisheries are crucial to the livelihoods of tens of millions of people; yet, widespread habitat degradation and unsustainable fishing are causing severe depletion of stocks of reef fish. Understanding how social and economic factors, such as human population density, access to external markets, and modernization interact with fishing and habitat degradation to affect fish stocks is vital to sustainable management of coral reef fisheries. We used fish survey data, national social and economic data, and path analyses to assess whether these factors explain variation in biomass of coral reef fishes among 25 sites in Solomon Islands. We categorized fishes into 3 groups on the basis of life-history characteristics associated with vulnerability to extinction by fishing (high, medium, and low vulnerability). The biomass of fish with low vulnerability was positively related to habitat condition. The biomass of fishes with high vulnerability was negatively related to fishing conducted with efficient gear. Use of efficient gear, in turn, was strongly and positively related to both population density and market proximity. This result suggests local population pressure and external markets have additive negative effects on vulnerable reef fish. Biomass of the fish of medium vulnerability was not explained by fishing intensity or habitat condition, which suggests these species may be relatively resilient to both habitat degradation and fishing.

  16. Evaluation of Midwater Trawl Selectivity and its Influence on Acoustic-Based Fish Population Surveys

    NASA Astrophysics Data System (ADS)

    Williams, Kresimir

    Trawls are used extensively during fisheries abundance surveys to derive estimates of fish density and, in the case of acoustic-based surveys, to identify acoustically sampled fish populations. However, trawls are selective in what fish they retain, resulting in biased estimates of density, species, and size compositions. Selectivity of the midwater trawl used in acoustic-based surveys of walleye pollock (Theragra chalcogramma) was evaluated using multiple methods. The effects of trawl selectivity on the acoustic-based survey abundance estimates and the stock assessment were evaluated for the Gulf of Alaska walleye pollock population. Selectivity was quantified using recapture, or pocket, nets attached to the outside of the trawl. Pocket net catches were modeled using a hierarchical Bayesian model to provide uncertainty in selectivity parameter estimates. Significant under-sampling of juvenile pollock by the midwater trawl was found, with lengths at 50% retention ranging from 14--26 cm over three experiments. Escapement was found to be light dependent, with more fish escaping in dark conditions. Highest escapement rates were observed in the aft of the trawl near to the codend though the bottom panel of the trawl. The behavioral mechanisms involved in the process of herding and escapement were evaluated using stereo-cameras, a DIDSON high frequency imaging sonar, and pocket nets. Fish maintained greater distances from the trawl panel during daylight, suggesting trawl modifications such as increased visibility of netting materials may evoke stronger herding responses and increased retention of fish. Selectivity and catchability of pollock by the midwater trawl was also investigated using acoustic density as an independent estimate of fish abundance to compare with trawl catches. A modeling framework was developed to evaluate potential explanatory factors for selectivity and catchability. Selectivity estimates were dependent on which vessel was used for the survey

  17. Anaphylaxis in the young adult population.

    PubMed

    Gupta, Ruchi S

    2014-01-01

    It is critical that clinicians treating young adults understand the presentation and management of anaphylaxis. The most common trigger for anaphylaxis in this population is food. The prevalence of food allergy is growing, with 8% of US children and adolescents affected. All patients at risk for anaphylaxis should be prescribed epinephrine autoinjectors, as epinephrine is the only life-saving medication for a severe anaphylactic reaction. The presentation of anaphylaxis can involve multiple organ systems (eg, mucocutaneous, respiratory, cardiovascular, gastrointestinal) and, as such, patient education is needed to assist in prompt recognition. Appropriate training of patients and caregivers about how to identify anaphylaxis and what to do in an emergency is critical. Training of school and college staff also is essential, as 1 in 4 first-time reactions occurs outside the home. Additional counseling for adolescents at risk for anaphylactic reactions should address increased risk-taking behavior, decreased adult supervision, dating, and the transition of disease management from an adult to the patient.

  18. Prevalence of sleepwalking in an adult population

    PubMed Central

    Mume, Celestine Okorome

    2010-01-01

    Background Sleepwalking consists of a series of behavioral activities that occur during sleep. These activities may be simple, complex or aggressive in nature. They include motor activities, confusion, and amnesia for the events. Sleepwalking is a disorder of arousal from non-rapid eye movement (NREM) sleep. In children, episodes of sleepwalking are rarely violent; in adults, however, sleepwalking might include violence, which could endanger the patient or others and might precipitate legal issues. There is inadequate information on the prevalence and demographic correlates of sleepwalking in Nigeria. Objectives One objective of this study was to determine the lifetime prevalence rate of sleepwalking in an adult population in Ile-Ife, in Southwestern Nigeria. Another objective was to determine the age and sex distribution of sleepwalking among those who have experienced it at least once in their lifetime. Materials and Methods A random sample of 228 healthy individuals aged 18–60 years was obtained and the members were asked to fill out a survey form about lifetime prevalence rate of sleepwalking. Results The overall lifetime prevalence rate of sleepwalking was 7% (16 of 228 participants). It was 10.4% in males and 3.5% in females, but the difference was not statistically significant (p=0.07). Conclusion This study has shown that sleepwalking is common in the population. In view of the psychological effects of sleepwalking and the potential physical and legal problems associated with it, adequate efforts should be made for early detection and prompt management of the condition. PMID:21483553

  19. ADAPTIONS OF WILD POPULATIONS OF THE ESTUARINE FISH FUNDULUS HETEROCLITUS TO PERSISTENT ENVIRONMENTAL CONTAMINANTS

    EPA Science Inventory

    Many aquatic species, including the estuarine fish Fundulus heteroclitus (mummichogs), adapt to local environmental conditions. We conducted studies to evaluate whether highly exposed populations of mummichogs adapt to toxic environmental contaminants. These fish populations are ...

  20. Adult and larval traits as determinants of geographic range size among tropical reef fishes

    PubMed Central

    Luiz, Osmar J.; Allen, Andrew P.; Robertson, D. Ross; Floeter, Sergio R.; Kulbicki, Michel; Vigliola, Laurent; Becheler, Ronan; Madin, Joshua S.

    2013-01-01

    Most marine organisms disperse via ocean currents as larvae, so it is often assumed that larval-stage duration is the primary determinant of geographic range size. However, empirical tests of this relationship have yielded mixed results, and alternative hypotheses have rarely been considered. Here we assess the relative influence of adult and larval-traits on geographic range size using a global dataset encompassing 590 species of tropical reef fishes in 47 families, the largest compilation of such data to date for any marine group. We analyze this database using linear mixed-effect models to control for phylogeny and geographical limits on range size. Our analysis indicates that three adult traits likely to affect the capacity of new colonizers to survive and establish reproductive populations (body size, schooling behavior, and nocturnal activity) are equal or better predictors of geographic range size than pelagic larval duration. We conclude that adult life-history traits that affect the postdispersal persistence of new populations are primary determinants of successful range extension and, consequently, of geographic range size among tropical reef fishes. PMID:24065830

  1. Adult and larval traits as determinants of geographic range size among tropical reef fishes.

    PubMed

    Luiz, Osmar J; Allen, Andrew P; Robertson, D Ross; Floeter, Sergio R; Kulbicki, Michel; Vigliola, Laurent; Becheler, Ronan; Madin, Joshua S

    2013-10-01

    Most marine organisms disperse via ocean currents as larvae, so it is often assumed that larval-stage duration is the primary determinant of geographic range size. However, empirical tests of this relationship have yielded mixed results, and alternative hypotheses have rarely been considered. Here we assess the relative influence of adult and larval-traits on geographic range size using a global dataset encompassing 590 species of tropical reef fishes in 47 families, the largest compilation of such data to date for any marine group. We analyze this database using linear mixed-effect models to control for phylogeny and geographical limits on range size. Our analysis indicates that three adult traits likely to affect the capacity of new colonizers to survive and establish reproductive populations (body size, schooling behavior, and nocturnal activity) are equal or better predictors of geographic range size than pelagic larval duration. We conclude that adult life-history traits that affect the postdispersal persistence of new populations are primary determinants of successful range extension and, consequently, of geographic range size among tropical reef fishes.

  2. Evaluating and understanding fish health risks and their consequences in propagated and free-ranging fish populations

    USGS Publications Warehouse

    Moffitt, C.M.; Haukenes, A.H.; Williams, C.J.

    2005-01-01

    Fishery managers and resource conservationists are increasingly interested in understanding the fish health and disease risks of free-ranging fishes and whether propagated fishes or features and practices used at fish culture facilities pose a health risk to free-ranging populations. Disease agents are present in most both captive and all free-ranging fish populations, but the consequences and extent of infections in free-ranging populations are often difficult to measure, control, and understand. Sampling methods, protocols, and assay techniques developed to assess the health of captive populations are not as applicable for assessments of free-ranging fishes. The use of chemicals and therapeutics to control diseases and parasites in propagated fishes likely reduces the risk of introducing specific pathogens into the environment, but control measures may have localized effects on the environment surrounding fish culture facilities. To understand health risks of propagated and free ranging fishes, we must consider fish populations, culture facilities, fish releases, and their interactions within the greater geospatial features of the aquatic environment. ?? 2004 by the American Fisheries Society.

  3. Evaluation of Juvenile Fish Bypass and Adult Fish Facilities at Water Diversions in the Umatilla River; 1992 Annual Report.

    SciTech Connect

    Knapp, Suzanne M.

    1993-03-01

    We report on our progress from October 1991 through September 1992 in evaluating juvenile fish bypass facilities at Three Mile Falls and Westland dams on the Umatilla River. We also report on our progress from October 1991 through June 1992 in evaluating adult fish passage in the lower Umatilla River and adult fish passage facilities at Three Mile Falls Dam. The study is a cooperative effort by the Oregon Department of Fish and Wildlife (ODFW) and the Confederated Tribes of the Umatilla Indian Reservation (CTUIR). These are the study objectives addressed by ODFW and CTUIR: (1) Report A (ODFW): To evaluate the juvenile fish bypass facility in the West Extension Irrigation District Canal at Three Mile Falls Dam and document juvenile salmonid passage through the juvenile fish bypass facility and east-bank adult fish ladder. To measure velocity and develop trap designs at Westland Dam. (2) Report B (CTUIR): To examine the passage of adult salmonids at Three Mile Falls Dam. The study is part of a program to rehabilitate anadromous fish stocks in the Umatilla River Basin, including restoration of coho salmon (Oncorhynchus kisutch) and chinook salmon (Oncorhynchus tshawytscha), as well as enhancement of summer steelhead (Oncorhynchus mykiss).

  4. Compensatory mechanisms in fish populations: Literature reviews: Volume 2, Compensation in fish populations subject to catastrophic impact: Final report

    SciTech Connect

    Jude, D.J.; Mansfield, P.J.; Schneeberger, P.J.; Wojcik, J.A.

    1987-05-01

    This study comprises an extensive literature review, critical evaluations of case histories, and considered recommendations for future research on the mechanisms and extent of compensation by various fish species subject to catastrophic impacts. ''Catastrophic impact'' was defined as an event which removes some limitation (such as food or space) on a fish population. Those events studied included new species introduction, toxic spills, exploitation of specific fish populations, and drawdown. The fish studied each had more than one compensatory mechanism available, and thus were able to respond to a catastrophic event even if an option was removed. Predation, overfishing, competition, disease, and parasitism are all potential catastrophies, but were found not to cause a catastrophic impact (except in special cases). In general, compensatory responses were determined to vary widely, even for species which perform fairly similar functions in an ecosystem. The extensive nature of this study, however, pointed up the many data gaps in the existing literature; recommendations are therefore made for followup research and expansion of ongoing monitoring programs, based on an evaluation of their relative importance.

  5. Daily mercury intake in fish-eating populations in the Brazilian Amazon.

    PubMed

    Passos, Carlos José Sousa; Da Silva, Delaine Sampaio; Lemire, Mélanie; Fillion, Myriam; Guimarães, Jean Rémy Davée; Lucotte, Marc; Mergler, Donna

    2008-01-01

    Although high levels of fish consumption and bioindicators of mercury exposure have been reported for traditional populations in the Amazon, little is known about their actual daily intake of Hg. Using an ecosystem approach, calculate daily mercury intake in adult fish-eaters, examine the relations between mercury intake and bioindicators of exposure and the factors that influence these relations. A cross-sectional dietary survey on fish and fruit consumption frequency was carried out with 256 persons from six villages of the Tapajós River. Fish portion per meal was determined. Mercury concentration was determined for 1123 local fish specimens. Daily mercury intake (microg/kg/day) was determined for men and women from each village using the average fish-mercury concentration for the fish caught in their fishing zone, the average quantity of fish per meal, fish-species frequency consumption and participants' body weight. Fish-mercury averaged 0.33 microg/g+/-0.33. Daily mercury intake varied between 0 and 11.8 microg/kg/day (mean 0.92 microg/kg/day+/-0.89) and varied by gender and village. Mean blood- and hair-mercury were 58.7+/-36.1 microg/l and 17.9+/-11.5 microg/g, respectively. There was a strong and positive relation between blood-mercury and daily mercury intake, with an inverse relation for fruit intake and schooling; significant variations were observed with immigrant status, and among villages. Hair-mercury was directly associated with daily mercury intake and inversely related to schooling and fruit consumption. Fruit consumption modified the relation between daily mercury intake and blood-mercury levels: for the same daily mercury intake, persons eating more fruit had lower blood-mercury concentrations (ANCOVA Interaction term: F=10.9, P<0.0001). The median difference of the ratio of blood-mercury to daily mercury intake between low and high fruit consumers was 26, representing a 26.3% reduction. These findings reveal high levels of daily mercury intake

  6. Impacts of the live reef fish trade on populations of coral reef fish off northern Borneo

    PubMed Central

    Scales, Helen; Balmford, Andrew; Manica, Andrea

    2007-01-01

    The live reef fish trade (LRFT) is one of the greatest but least-quantified sources of fishing pressure for several species of large coral reef fish across the Indo-Pacific. For the first time we quantify the localized impact of the LRFT. We collected data from three LRFT traders in northern Borneo, which yielded information on daily fishing effort and the species and mass of all fishes sold every day by individual fishers or vessels over 2, 3 and 8 years. Total monthly catch and relative abundance (catch-per-unit-effort) declined significantly in several species, including the most valuable species the Napoleon wrasse (Cheilinus undulatus, estimated changes of −98 and −78% over 8 years in catch and relative abundance, respectively) and lower-value bluelined groupers (Plectropomus oligocanthus: −99 and −81%) and Epinephelus groupers (−89 and −32%). These severe declines were rapid, species-specific and occurred in the first 2–4 years of the dataset and are, we believe, directly attributable to the LRFT. This has crucial implications for future data collection and monitoring if population collapses in other parts of the LRFT and similar wildlife trades are to be successfully detected. PMID:17251096

  7. Impacts of the live reef fish trade on populations of coral reef fish off northern Borneo.

    PubMed

    Scales, Helen; Balmford, Andrew; Manica, Andrea

    2007-04-01

    The live reef fish trade (LRFT) is one of the greatest but least-quantified sources of fishing pressure for several species of large coral reef fish across the Indo-Pacific. For the first time we quantify the localized impact of the LRFT. We collected data from three LRFT traders in northern Borneo, which yielded information on daily fishing effort and the species and mass of all fishes sold every day by individual fishers or vessels over 2, 3 and 8 years. Total monthly catch and relative abundance (catch-per-unit-effort) declined significantly in several species, including the most valuable species the Napoleon wrasse (Cheilinus undulatus, estimated changes of -98 and -78% over 8 years in catch and relative abundance, respectively) and lower-value bluelined groupers (Plectropomus oligocanthus: -99 and -81%) and Epinephelus groupers (-89 and -32%). These severe declines were rapid, species-specific and occurred in the first 2-4 years of the dataset and are, we believe, directly attributable to the LRFT. This has crucial implications for future data collection and monitoring if population collapses in other parts of the LRFT and similar wildlife trades are to be successfully detected.

  8. An analysis of mercury exposures among the adult population in New York State.

    PubMed

    Fletcher, Alicia M; Gelberg, Kitty H

    2013-06-01

    The extent of methylmercury exposures among adults in New York State (NYS) has not been well characterized. Over the past few years, the NYS Heavy Metals Registry (HMR) has seen an increase in both blood mercury tests being reported, and nonoccupational exposures to mercury, which appear primarily due to fish consumption. This study will, (1) Characterize the adults who are tested for blood mercury in NYS; (2) Examine the circumstances for blood mercury testing; and (3) Characterize this population in terms of exposure history, specifically those individuals who are non-occupationally exposed through a diet of seafood consumption in reference to blood mercury levels. Data available from HMR laboratory results, including basic demographics and test results, were combined with data from telephone interviews. The interview contains information on the reasons for testing, possible sources of exposure, and the individual's work and home environment. Approximately 99 % of adults reported to the HMR, with identifiable exposures to mercury, had non-occupational exposures resulting from seafood consumption. Common types of fish consumed include salmon, tuna, and swordfish, with 90 % of adults eating seafood a few times or more per week. Information will be provided on the reasons for being tested and the range of blood mercury levels in relation to their seafood consumption. NYS residents who frequently eat fish should be aware of what types of fish contain mercury and avoid or reduce consumption of fish with high mercury levels. PMID:23264151

  9. Long-Term Changes in the Distributions of Larval and Adult Fish in the Northeast U.S. Shelf Ecosystem.

    PubMed

    Walsh, Harvey J; Richardson, David E; Marancik, Katrin E; Hare, Jonathan A

    2015-01-01

    Many studies have documented long-term changes in adult marine fish distributions and linked these changes to climate change and multi-decadal climate variability. Most marine fish, however, have complex life histories with morphologically distinct stages, which use different habitats. Shifts in distribution of one stage may affect the connectivity between life stages and thereby impact population processes including spawning and recruitment. Specifically, many marine fish species have a planktonic larval stage, which lasts from weeks to months. We compared the spatial distribution and seasonal occurrence of larval fish in the Northeast U.S. Shelf Ecosystem to test whether spatial and temporal distributions changed between two decades. Two large-scale ichthyoplankton programs sampled using similar methods and spatial domain each decade. Adult distributions from a long-term bottom trawl survey over the same time period and spatial area were also analyzed using the same analytical framework to compare changes in larval and adult distributions between the two decades. Changes in spatial distribution of larvae occurred for 43% of taxa, with shifts predominately northward (i.e., along-shelf). Timing of larval occurrence shifted for 49% of the larval taxa, with shifts evenly split between occurring earlier and later in the season. Where both larvae and adults of the same species were analyzed, 48% exhibited different shifts between larval and adult stages. Overall, these results demonstrate that larval fish distributions are changing in the ecosystem. The spatial changes are largely consistent with expectations from a changing climate. The temporal changes are more complex, indicating we need a better understanding of reproductive timing of fishes in the ecosystem. These changes may impact population productivity through changes in life history connectivity and recruitment, and add to the accumulating evidence for changes in the Northeast U.S. Shelf Ecosystem with

  10. Long-Term Changes in the Distributions of Larval and Adult Fish in the Northeast U.S. Shelf Ecosystem

    PubMed Central

    2015-01-01

    Many studies have documented long-term changes in adult marine fish distributions and linked these changes to climate change and multi-decadal climate variability. Most marine fish, however, have complex life histories with morphologically distinct stages, which use different habitats. Shifts in distribution of one stage may affect the connectivity between life stages and thereby impact population processes including spawning and recruitment. Specifically, many marine fish species have a planktonic larval stage, which lasts from weeks to months. We compared the spatial distribution and seasonal occurrence of larval fish in the Northeast U.S. Shelf Ecosystem to test whether spatial and temporal distributions changed between two decades. Two large-scale ichthyoplankton programs sampled using similar methods and spatial domain each decade. Adult distributions from a long-term bottom trawl survey over the same time period and spatial area were also analyzed using the same analytical framework to compare changes in larval and adult distributions between the two decades. Changes in spatial distribution of larvae occurred for 43% of taxa, with shifts predominately northward (i.e., along-shelf). Timing of larval occurrence shifted for 49% of the larval taxa, with shifts evenly split between occurring earlier and later in the season. Where both larvae and adults of the same species were analyzed, 48% exhibited different shifts between larval and adult stages. Overall, these results demonstrate that larval fish distributions are changing in the ecosystem. The spatial changes are largely consistent with expectations from a changing climate. The temporal changes are more complex, indicating we need a better understanding of reproductive timing of fishes in the ecosystem. These changes may impact population productivity through changes in life history connectivity and recruitment, and add to the accumulating evidence for changes in the Northeast U.S. Shelf Ecosystem with

  11. The Release Rate of Environmental DNA from Juvenile and Adult Fish

    PubMed Central

    Maruyama, Atsushi; Nakamura, Keisuke; Yamanaka, Hiroki; Kondoh, Michio; Minamoto, Toshifumi

    2014-01-01

    The environmental DNA (eDNA) technique is expected to become a powerful, non-invasive tool for estimating the distribution and biomass of organisms. This technique was recently shown to be applicable to aquatic vertebrates by collecting extraorganismal DNA floating in the water or absorbed onto suspended particles. However, basic information on eDNA release rate is lacking, despite it being essential for practical applications. In this series of experiments with bluegill sunfish (Lepomis macrochirus), we examined the effect of fish developmental stage on eDNA release rate. eDNA concentration reached equilibrium 3 days after the individual fish were introduced into the separate containers, enabling calculation of the eDNA release rate (copies h−1) from individual fish on the assumption that the number of eDNA released from the fish per unit time equals total degradation in the container (copies h−1). The eDNA release rate was 3–4 times higher in the adult (body weight: 30–75 g) than in the juvenile group (0.5–2.0 g). Such positive relationship between fish size and eDNA release rate support the possibility of biomass rather than density estimation using eDNA techniques. However, the eDNA release rate per fish body weight (copies h−1 g−1) was slightly higher in the juvenile than the adult group, which is likely because of the ontogenetic reduction in metabolic activity. Therefore, quantitative eDNA data should be carefully interpreted to avoid overestimating biomass when the population is dominated by juveniles, because the age structure of the focal population is often variable and unseen in the field. eDNA degradation rates (copies l−1 h−1), calculated by curve fitting of time-dependent changes in eDNA concentrations after fish removal, were 5.1–15.9% per hour (half-life: 6.3 h). This suggests that quantitative eDNA data should be corrected using a degradation curve attained in the target field. PMID:25479160

  12. Intensive studies of stream fish populations in Maine. Final report

    SciTech Connect

    Haines, T.A.; Norton, S.A.; Kahl, J.S.; Fay, C.W.; Pauwels, S.J.

    1990-05-01

    The National Acid Precipitation Assessment Program (NAPAP) was established by the Acid Precipitation Act of 1980 to develop and implement a program to increase understanding of the causes and effects of acidic deposition, and their history and prognosis. The objectives of the project were to determine the influence of precipitation chemistry, precipitation amount and character, and stream hydrologic components on biologically important stream chemistry parameters; and to determine the response of fish to episodic and chronic changes in these parameters. The authors selected six streams in eastern Maine for intensive monitoring of stream discharge, temperature, major chemical variables, and fish populations. The chronic effects of acid and Al on two Atlantic salmon life history stages were tested.

  13. Energetic and ecological constraints on population density of reef fishes.

    PubMed

    Barneche, D R; Kulbicki, M; Floeter, S R; Friedlander, A M; Allen, A P

    2016-01-27

    Population ecology has classically focused on pairwise species interactions, hindering the description of general patterns and processes of population abundance at large spatial scales. Here we use the metabolic theory of ecology as a framework to formulate and test a model that yields predictions linking population density to the physiological constraints of body size and temperature on individual metabolism, and the ecological constraints of trophic structure and species richness on energy partitioning among species. Our model was tested by applying Bayesian quantile regression to a comprehensive reef-fish community database, from which we extracted density data for 5609 populations spread across 49 sites around the world. Our results indicate that population density declines markedly with increases in community species richness and that, after accounting for richness, energetic constraints are manifested most strongly for the most abundant species, which generally are of small body size and occupy lower trophic groups. Overall, our findings suggest that, at the global scale, factors associated with community species richness are the major drivers of variation in population density. Given that populations of species-rich tropical systems exhibit markedly lower maximum densities, they may be particularly susceptible to stochastic extinction. PMID:26791611

  14. Energetic and ecological constraints on population density of reef fishes.

    PubMed

    Barneche, D R; Kulbicki, M; Floeter, S R; Friedlander, A M; Allen, A P

    2016-01-27

    Population ecology has classically focused on pairwise species interactions, hindering the description of general patterns and processes of population abundance at large spatial scales. Here we use the metabolic theory of ecology as a framework to formulate and test a model that yields predictions linking population density to the physiological constraints of body size and temperature on individual metabolism, and the ecological constraints of trophic structure and species richness on energy partitioning among species. Our model was tested by applying Bayesian quantile regression to a comprehensive reef-fish community database, from which we extracted density data for 5609 populations spread across 49 sites around the world. Our results indicate that population density declines markedly with increases in community species richness and that, after accounting for richness, energetic constraints are manifested most strongly for the most abundant species, which generally are of small body size and occupy lower trophic groups. Overall, our findings suggest that, at the global scale, factors associated with community species richness are the major drivers of variation in population density. Given that populations of species-rich tropical systems exhibit markedly lower maximum densities, they may be particularly susceptible to stochastic extinction.

  15. Evidence of population resistance to extreme low flows in a fluvial-dependent fish species

    USGS Publications Warehouse

    Katz, Rachel A.; Freeman, Mary C.

    2015-01-01

    Extreme low streamflows are natural disturbances to aquatic populations. Species in naturally intermittent streams display adaptations that enhance persistence during extreme events; however, the fate of populations in perennial streams during unprecedented low-flow periods is not well-understood. Biota requiring swift-flowing habitats may be especially vulnerable to flow reductions. We estimated the abundance and local survival of a native fluvial-dependent fish species (Etheostoma inscriptum) across 5 years encompassing historic low flows in a sixth-order southeastern USA perennial river. Based on capturemark-recapture data, the study shoal may have acted as a refuge during severe drought, with increased young-of-the-year (YOY) recruitment and occasionally high adult immigration. Contrary to expectations, summer and autumn survival rates (30 days) were not strongly depressed during low-flow periods, despite 25%-80% reductions in monthly discharge. Instead, YOY survival increased with lower minimum discharge and in response to small rain events that increased low-flow variability. Age-1+ fish showed the opposite pattern, with survival decreasing in response to increasing low-flow variability. Results from this population dynamics study of a small fish in a perennial river suggest that fluvial-dependent species can be resistant to extreme flow reductions through enhanced YOY recruitment and high survival

  16. Life-history correlates of maximum population growth rates in marine fishes.

    PubMed

    Denney, Nicola H; Jennings, Simon; Reynolds, John D

    2002-11-01

    Theory predicts that populations of animals with late maturity, low fecundity, large body size and low body growth rates will have low potential rates of population increase at low abundance. If this is true, then these traits may be used to predict the intrinsic rate of increase for species or populations, as well as extinction risks. We used life-history and population data for 63 stocks of commercially exploited fish species from the northeast Atlantic to test relationships between life-history parameters and the rate of population increase at low abundance. We used cross-taxonomic analyses among stocks and among species, and analyses that accounted for phylogenetic relationships. These analyses confirmed that large-bodied, slow-growing stocks and species had significantly lower rates of recruitment and adult production per spawning adult at low abundance. Furthermore, high ages at maturity were significantly correlated with low maximum recruit production. Contrary to expectation, fecundity was significantly negatively related to recruit production, due to its positive relationship with maximum body size. Our results support theoretical predictions, and suggest that a simply measured life-history parameter can provide a useful tool for predicting rates of recovery from low population abundance.

  17. Serum apolipoproteins in relation to intakes of fish in population of Arkhangelsk County

    PubMed Central

    2012-01-01

    Background Diets rich in omega-3 fatty acids and low in saturated fat were found beneficially associated with blood lipids and cardio-vascular health. Lean reindeer meet and local cold water white-fish species high in omega-3 are among the main sources of nutrients in the rural area of the Nenets Autonomous Okrug (NAO) in Russia and are not normally consumed by the urban population from the same region. The aims of the study were firstly, to compare serum lipid profiles of residents of urban (Arkhangelsk city) and rural (NAO) regions of Arkhangelsk County, and secondly, to investigate the effects of fish consumption on the predictor of cardiovascular events apolipoprotein (Apo) B/ApoA-I ratio in these populations. Methods A cross-sectional study conducted in Arkhangelsk County, Russia. Sample size of 249 adults: 132 subjects from Arkhangelsk city, aged 21–70 and 117 subject (87% Ethnic Nenets) from NAO, aged 18–69. Results We observed more favorable lipid levels in NAO compared to Arkhangelsk participants. Age-adjusted geometric means of ApoB/ApoA-I ratio were 1.02 and 0.98 in men and women from Arkhangelsk; 0.84 and 0.91 in men and women from NAO respectively. Age and consumption of animal fat were positively associated with ApoB/ApoA-I ratio in women (pooled samples from Arkhangelsk and NAO). Body mass index and low levels of physical activity were positively associated with ApoB/ApoA-I ratio in men (pooled samples from Arkhangelsk and NAO). Reported oily fish consumption was not significantly correlated with ApoB/ApoA-I ratio. Conclusion The population sample from rural NAO, consisting largely of the indigenous Arctic population Nenets with healthier dietary sources, had a relatively less atherogenic lipid profile compared to the urban Arkhangelsk group. Fish consumption had no effect on apolipoproteins profile. PMID:22681916

  18. Ocean acidification alters fish populations indirectly through habitat modification

    NASA Astrophysics Data System (ADS)

    Nagelkerken, Ivan; Russell, Bayden D.; Gillanders, Bronwyn M.; Connell, Sean D.

    2016-01-01

    Ocean ecosystems are predicted to lose biodiversity and productivity from increasing ocean acidification. Although laboratory experiments reveal negative effects of acidification on the behaviour and performance of species, more comprehensive predictions have been hampered by a lack of in situ studies that incorporate the complexity of interactions between species and their environment. We studied CO2 vents from both Northern and Southern hemispheres, using such natural laboratories to investigate the effect of ocean acidification on plant-animal associations embedded within all their natural complexity. Although we substantiate simple direct effects of reduced predator-avoidance behaviour by fishes, as observed in laboratory experiments, we here show that this negative effect is naturally dampened when fish reside in shelter-rich habitats. Importantly, elevated CO2 drove strong increases in the abundance of some fish species through major habitat shifts, associated increases in resources such as habitat and prey availability, and reduced predator abundances. The indirect effects of acidification via resource and predator alterations may have far-reaching consequences for population abundances, and its study provides a framework for a more comprehensive understanding of increasing CO2 emissions as a driver of ecological change.

  19. Large scale, synchronous variability of marine fish populations driven by commercial exploitation.

    PubMed

    Frank, Kenneth T; Petrie, Brian; Leggett, William C; Boyce, Daniel G

    2016-07-19

    Synchronous variations in the abundance of geographically distinct marine fish populations are known to occur across spatial scales on the order of 1,000 km and greater. The prevailing assumption is that this large-scale coherent variability is a response to coupled atmosphere-ocean dynamics, commonly represented by climate indexes, such as the Atlantic Multidecadal Oscillation and North Atlantic Oscillation. On the other hand, it has been suggested that exploitation might contribute to this coherent variability. This possibility has been generally ignored or dismissed on the grounds that exploitation is unlikely to operate synchronously at such large spatial scales. Our analysis of adult fishing mortality and spawning stock biomass of 22 North Atlantic cod (Gadus morhua) stocks revealed that both the temporal and spatial scales in fishing mortality and spawning stock biomass were equivalent to those of the climate drivers. From these results, we conclude that greater consideration must be given to the potential of exploitation as a driving force behind broad, coherent variability of heavily exploited fish species.

  20. Using Fish Population Metrics to Compare the Effects of Artificial Reef Density

    PubMed Central

    2015-01-01

    Artificial reefs continue to be added as habitat throughout the world, yet questions remain about how reef design affects fish diversity and abundance. In the present study, the effects of reef density were assessed for fish communities and sizes of economically valuable Lutjanus campechanus 13 km off Port Mansfield, Texas, at a reef composed of more than 4000 concrete culverts. The study spanned from May to June in 2013 and 2014, and sites sampled included natural reefs, bare areas, and varying culvert patch density categories, ranging from 1–190 culverts. Abundances of adults and species evenness of juvenile populations differed between the years. Fish communities did not significantly differ among density categories; however, highest species richness and total abundances were observed at intermediate culvert densities and at natural reefs. Whereas the abundance of L. campechanus did not differ among density categories, mean total lengths of L. campechanus were greatest at the lower density. Our findings suggest that reefs should be deployed with intermediate patch density of 71–120 culverts in a 30-m radius to yield the highest fish abundances. PMID:26422472

  1. Using Fish Population Metrics to Compare the Effects of Artificial Reef Density.

    PubMed

    Froehlich, Catheline Y M; Kline, Richard J

    2015-01-01

    Artificial reefs continue to be added as habitat throughout the world, yet questions remain about how reef design affects fish diversity and abundance. In the present study, the effects of reef density were assessed for fish communities and sizes of economically valuable Lutjanus campechanus 13 km off Port Mansfield, Texas, at a reef composed of more than 4000 concrete culverts. The study spanned from May to June in 2013 and 2014, and sites sampled included natural reefs, bare areas, and varying culvert patch density categories, ranging from 1-190 culverts. Abundances of adults and species evenness of juvenile populations differed between the years. Fish communities did not significantly differ among density categories; however, highest species richness and total abundances were observed at intermediate culvert densities and at natural reefs. Whereas the abundance of L. campechanus did not differ among density categories, mean total lengths of L. campechanus were greatest at the lower density. Our findings suggest that reefs should be deployed with intermediate patch density of 71-120 culverts in a 30-m radius to yield the highest fish abundances.

  2. Use of rehabilitation experiments to understand the recovery dynamics of acid-stressed fish populations.

    PubMed

    Snucins, Ed; Gunn, John M

    2003-04-01

    We used rehabilitation experiments involving the stocking of 2 native sportfish, lake trout (Salvelinus namaycush) and smallmouth bass (Micropterus dolomieu), in combination with recent fish community surveys, to study the recovery dynamics of fish populations in acid-stressed lakes near Sudbury and Killarney, Ontario, Canada. Population recovery rates differed between the 2 species. Introduced lake trout did poorly in species-rich lakes and exhibited slower growth, lower survival and delayed recruitment. Smallmouth bass, in contrast, readily colonized species-rich lakes. The biomass of natural smallmouth bass recruits increased to reference lake levels within 5 years following water quality recovery and spawning by stocked fish, whereas the biomass of natural lake trout recruits remained well below reference levels 5-15 years after water quality recovery and spawning by adults occurred. We document introductions by anglers of smallmouth bass into acid-damaged lake trout lakes, including some lakes that did not contain bass prior to acidification. This range expansion of a warm-water species (bass) that can alter food-web structure and reduce the growth of a cold-water species (trout), illustrates the potential for the combination of climate warming and species introductions to greatly alter the biological recovery endpoints in acid-stressed lakes.

  3. Evaluation of Juvenile Fish Bypass and Adult Fish Passage Facilities at Water Diversions in the Umatilla River; 1993 Annual Report.

    SciTech Connect

    Knapp, Suzanne M.

    1994-03-01

    This report presents progress from October 1992 through September 1993 in evaluating juvenile fish bypass facilities at Three Mile Falls, Maxwell, Westland, and Feed Canal dams on the Umatilla River, and in evaluating adult fish passage in the lower Umatilla River. Also reported is an effort to evaluate delayed mortality and stress responses of juvenile salmonids resulting from trapping and transport at high temperatures. These studies are part of a program to rehabilitate anadromous fish stocks in the matilla River Basin, including restoration of coho salmon and chinook salmon, as well as enhancement of summer steelhead.

  4. Mapping the Misunderstood Population of Adult Students

    ERIC Educational Resources Information Center

    Ashburn, Elyse

    2007-01-01

    Adult students are not well documented, are frequently left out of discussions of higher-education policy, and are not fully understood by the colleges they attend, says a report ("Returning to Learning: Adults' Success in College is Key to America's Future") released this week by the Lumina Foundation for Education. As a result, those students…

  5. Consumption dynamics of the adult piscivorous fish community in Spirit Lake, Iowa

    USGS Publications Warehouse

    Liao, H.; Pierce, C.L.; Larscheid, J.G.

    2004-01-01

    At Spirit Lake, one of Iowa's most important fisheries, walleye Sander vitreus (formerly Stizostedion vitreum) is one of the most popular species with anglers. Despite a century of walleye stocking and management in Spirit Lake, walleye growth rate, size structure, and angler harvest continue to decline. Our purpose was to determine the magnitude and dynamics of walleye population consumption relative to those of other piscivorous species in Spirit Lake, which would allow managers to judge the feasibility of increasing the abundance, growth rate, and size structure of the walleye population. We quantified food consumption by the adult piscivorous fish community in Spirit Lake over a 3-year period. Data on population dynamics, diet, energy density, and water temperature from 1995 to 1997 were used in bioenergetics models to estimate total consumption by walleye, yellow perch Perca flavescens, smallmouth bass Micropterus dolomieu, largemouth bass Micropterus salmoides, black crappie Pomoxis nigromaculatus, and northern pike Esox lucius. Estimated annual consumption by the piscivorous community varied roughly fourfold, ranging from 154,752 kg in 1995 to 662,776 kg in 1997. Walleyes dominated total consumption, accounting for 68, 73, and 90% (1995-1997, respectively) of total food consumption. Walleyes were also the dominant consumers of fish, accounting for 76, 86, and 97% of piscivorous consumption; yellow perch followed, accounting for 16% of piscivorous consumption in 1995 and 12% in 1996. Yellow perch were the predominant fish prey species in all 3 years, accounting for 68, 52, and 36% of the total prey consumed. Natural reproduction is weak, so high walleye densities are maintained by intensive stocking. Walleye stocking drives piscivorous consumption in Spirit Lake, and yearly variation in the cannibalism of stocked walleye fry may be an important determinant of walleye year-class strength and angler success. Reducing walleye stocking intensity, varying stocking

  6. Life cycle ecophysiology of small pelagic fish and climate-driven changes in populations

    NASA Astrophysics Data System (ADS)

    Peck, Myron A.; Reglero, Patricia; Takahashi, Motomitsu; Catalán, Ignacio A.

    2013-09-01

    Due to their population characteristics and trophodynamic role, small pelagic fishes are excellent bio-indicators of climate-driven changes in marine systems world-wide. We argue that making robust projections of future changes in the productivity and distribution of small pelagics will require a cause-and-effect understanding of historical changes based upon physiological principles. Here, we reviewed the ecophysiology of small pelagic (clupeiform) fishes including a matrix of abiotic and biotic extrinsic factors (e.g., temperature, salinity, light, and prey characteristics) and stage-specific vital rates: (1) adult spawning, (2) survival and development of eggs and yolk sac larvae, and (3) feeding and growth of larvae, post-larvae and juveniles. Emphasis was placed on species inhabiting Northwest Pacific and Northeast Atlantic (European) waters for which summary papers are particularly scarce compared to anchovy and sardine in upwelling systems. Our review revealed that thermal niches (optimal and sub-optimal ranges in temperatures) were species- and stage-specific but that temperature effects only partly explained observed changes in the distribution and/or productivity of populations in the Northwest Pacific and Northeast Atlantic; changes in temperature may be necessary but not sufficient to induce population-level shifts. Prey availability during the late larval and early juvenile period was a common, density-dependent mechanism linked to fluctuations in populations but recruitment mechanisms were system-specific suggesting that generalizations of climate drivers across systems should be avoided. We identified gaps in knowledge regarding basic elements of the growth physiology of each life stage that will require additional field and laboratory study. Avenues of research are recommended that will aid the development of models that provide more robust, physiological-based projections of the population dynamics of these and other small pelagic fish. In our

  7. Archaeological evidence of validity of fish populations on unexploited reefs as proxy targets for modern populations.

    PubMed

    Longenecker, Ken; Chan, Yvonne L; Toonen, Robert J; Carlon, David B; Hunt, Terry L; Friedlander, Alan M; Demartini, Edward E

    2014-10-01

    Reef-fish management and conservation is hindered by a lack of information on fish populations prior to large-scale contemporary human impacts. As a result, relatively pristine sites are often used as conservation baselines for populations near sites affected by humans. This space-for-time approach can only be validated by sampling assemblages through time. We used archaeological remains to evaluate whether the remote, uninhabited Northwestern Hawaiian Islands (NWHI) might provide a reasonable proxy for a lightly exploited baseline in the Main Hawaiian Islands (MHI). We used molecular and morphological techniques to describe the taxonomic and size composition of the scarine parrotfish catches present in 2 archaeological assemblages from the MHI, compared metrics of these catches with modern estimates of reproductive parameters to evaluate whether catches represented by the archaeological material were consistent with sustainable fishing, and evaluated overlap between size structures represented by the archaeological material and modern survey data from the MHI and the NWHI to assess whether a space-for-time substitution is reasonable. The parrotfish catches represented by archaeological remains were consistent with sustainable fishing because they were dominated by large, mature individuals whose average size remained stable from prehistoric (AD approximately 1400-1700) through historic (AD 1700-1960) periods. The ancient catches were unlike populations in the MHI today. Overlap between the size structure of ancient MHI catches and modern survey data from the NWHI or the MHI was an order of magnitude greater for the NWHI comparison, a result that supports the validity of using the NWHI parrotfish data as a proxy for the MHI before accelerated, heavy human impacts in modern times.

  8. Subtle genetic structure reveals restricted connectivity among populations of a coral reef fish inhabiting remote atolls.

    PubMed

    Underwood, Jim N; Travers, Michael J; Gilmour, James P

    2012-03-01

    We utilized a spatial and temporal analyses of genetic structure, supplemented with ecological and oceanographic analysis, to assess patterns of population connectivity in a coral reef fish Chromis margaritifer among the unique and remote atolls in the eastern Indian Ocean. A subtle, but significant genetic discontinuity at 10 microsatellite DNA loci was detected between atoll systems corresponding with a low (≤ 1%) probability of advection across the hundreds of kilometers of open ocean that separates them. Thus, although genetic connections between systems are likely maintained by occasional long-distance dispersal of C. margaritifer larvae, ecological population connectivity at this spatial scale appears to be restricted. Further, within one of these atoll systems, significant spatial differentiation among samples was accompanied by a lack of temporal pairwise differentiation between recruit and adult samples, indicating that restrictions to connectivity also occur at a local scale (tens of kilometers). In contrast, a signal of panmixia was detected at the other atoll system studied. Lastly, greater relatedness and reduced genetic diversity within recruit samples was associated with relatively large differences among them, indicating the presence of sweepstakes reproduction whereby a small proportion of adults contributes to recruitment in the next generation. These results are congruent with earlier work on hard corals, suggesting that local production of larvae drives population replenishment in these atoll systems for a range of coral reef species. PMID:22822442

  9. Subtle genetic structure reveals restricted connectivity among populations of a coral reef fish inhabiting remote atolls.

    PubMed

    Underwood, Jim N; Travers, Michael J; Gilmour, James P

    2012-03-01

    We utilized a spatial and temporal analyses of genetic structure, supplemented with ecological and oceanographic analysis, to assess patterns of population connectivity in a coral reef fish Chromis margaritifer among the unique and remote atolls in the eastern Indian Ocean. A subtle, but significant genetic discontinuity at 10 microsatellite DNA loci was detected between atoll systems corresponding with a low (≤ 1%) probability of advection across the hundreds of kilometers of open ocean that separates them. Thus, although genetic connections between systems are likely maintained by occasional long-distance dispersal of C. margaritifer larvae, ecological population connectivity at this spatial scale appears to be restricted. Further, within one of these atoll systems, significant spatial differentiation among samples was accompanied by a lack of temporal pairwise differentiation between recruit and adult samples, indicating that restrictions to connectivity also occur at a local scale (tens of kilometers). In contrast, a signal of panmixia was detected at the other atoll system studied. Lastly, greater relatedness and reduced genetic diversity within recruit samples was associated with relatively large differences among them, indicating the presence of sweepstakes reproduction whereby a small proportion of adults contributes to recruitment in the next generation. These results are congruent with earlier work on hard corals, suggesting that local production of larvae drives population replenishment in these atoll systems for a range of coral reef species.

  10. Subtle genetic structure reveals restricted connectivity among populations of a coral reef fish inhabiting remote atolls

    PubMed Central

    Underwood, Jim N; Travers, Michael J; Gilmour, James P

    2012-01-01

    We utilized a spatial and temporal analyses of genetic structure, supplemented with ecological and oceanographic analysis, to assess patterns of population connectivity in a coral reef fish Chromis margaritifer among the unique and remote atolls in the eastern Indian Ocean. A subtle, but significant genetic discontinuity at 10 microsatellite DNA loci was detected between atoll systems corresponding with a low (≤ 1%) probability of advection across the hundreds of kilometers of open ocean that separates them. Thus, although genetic connections between systems are likely maintained by occasional long-distance dispersal of C. margaritifer larvae, ecological population connectivity at this spatial scale appears to be restricted. Further, within one of these atoll systems, significant spatial differentiation among samples was accompanied by a lack of temporal pairwise differentiation between recruit and adult samples, indicating that restrictions to connectivity also occur at a local scale (tens of kilometers). In contrast, a signal of panmixia was detected at the other atoll system studied. Lastly, greater relatedness and reduced genetic diversity within recruit samples was associated with relatively large differences among them, indicating the presence of sweepstakes reproduction whereby a small proportion of adults contributes to recruitment in the next generation. These results are congruent with earlier work on hard corals, suggesting that local production of larvae drives population replenishment in these atoll systems for a range of coral reef species. PMID:22822442

  11. Fish collagen is an important panallergen in the Japanese population.

    PubMed

    Kobayashi, Y; Akiyama, H; Huge, J; Kubota, H; Chikazawa, S; Satoh, T; Miyake, T; Uhara, H; Okuyama, R; Nakagawara, R; Aihara, M; Hamada-Sato, N

    2016-05-01

    Collagen was identified as a fish allergen in early 2000s. Although its allergenic potential has been suggested to be low, risks associated with collagen as a fish allergen have not been evaluated to a greater extent. In this study, we aimed to clarify the importance of collagen as a fish allergen. Our results showed that 50% of Japanese patients with fish allergy had immunoglobulin E (IgE) against mackerel collagen, whereas 44% had IgE against mackerel parvalbumin. IgE inhibition assay revealed high cross-reactivity of mackerel collagen to 22 fish species (inhibition rates: 87-98%). Furthermore, a recently developed allergy test demonstrated that collagen triggered IgE cross-linking on mast cells. These data indicate that fish collagen is an important and very common panallergen in fish consumed in Japan. The high rate of individuals' collagen allergy may be attributable to the traditional Japanese custom of raw fish consumption. PMID:26785247

  12. RSV infection in the adult population.

    PubMed

    Ramirez, Julio A

    2008-11-01

    RSV is a significant and unrecognized cause of seasonal RTIs in adults, accounting for as much as 25 percent of excess wintertime mortality usually attributed to influenza. Nearly 80 percent of RSV-associated underlying respiratory and circulatory deaths occur among the elderly, and RSV is estimated to account for about 180,000 hospital admissions each year at a cost exceeding $1 billion. RSV also is recognized as an important cause of viral pneumonia in adults. Preventive measures, such as hand washing, are paramount, especially in hospitals and nursing homes where many immunocompromised patients reside. When RSV is circulating, it is advisable to minimize contact between high-risk patients and children.

  13. Toxicology across scales: Cell population growth in vitro predicts reduced fish growth

    PubMed Central

    Stadnicka-Michalak, Julita; Schirmer, Kristin; Ashauer, Roman

    2015-01-01

    Environmental risk assessment of chemicals is essential but often relies on ethically controversial and expensive methods. We show that tests using cell cultures, combined with modeling of toxicological effects, can replace tests with juvenile fish. Hundreds of thousands of fish at this developmental stage are annually used to assess the influence of chemicals on growth. Juveniles are more sensitive than adult fish, and their growth can affect their chances to survive and reproduce. Thus, to reduce the number of fish used for such tests, we propose a method that can quantitatively predict chemical impact on fish growth based on in vitro data. Our model predicts reduced fish growth in two fish species in excellent agreement with measured in vivo data of two pesticides. This promising step toward alternatives to fish toxicity testing is simple, inexpensive, and fast and only requires in vitro data for model calibration. PMID:26601229

  14. Fish population dynamics revealed by instantaneous continental-shelf scale acoustic imaging

    NASA Astrophysics Data System (ADS)

    Ratilal, Purnima; Symonds, Deanelle; Makris, Nicholas C.; Nero, Redwood

    2005-04-01

    Video images of fish population densities over vast areas of the New Jersey continental shelf have been produced from acoustic data collected on a long range bistatic sonar system during the Acoustic Clutter 2003 experiment. Areal fish population densities were obtained after correcting the acoustic data for two-way transmission loss modeled using the range-dependent parabolic equation, spatially varying beampattern of the array, source level and mean target strength per fish. The wide-area fish density images reveal the temporal evolution of fish school distributions, their migration, as well as shoal formation and fragmentation at 50 s interval. Time series of the fish population within various density thresholds were made over the period of a day in an area containing millions of fish that at some instances formed a massive shoal extending over 12 km. The analysis shows that fish population in the area can be decomposed into a stable ambient population from lower-fish-density regions and a time-varying population composed from higher-density regions. Estimates of the differential speed between population centers of various shoals show that the average speed is on the order of a slow-moving surface vessel or submarine.

  15. Fish consumption pattern among adults of different ethnics in Peninsular Malaysia

    PubMed Central

    Ahmad, Nurul Izzah; Wan Mahiyuddin, Wan Rozita; Tengku Mohamad, Tengku Rozaina; Ling, Cheong Yoon; Daud, Siti Fatimah; Hussein, Nasriyah Che; Abdullah, Nor Aini; Shaharudin, Rafiza; Sulaiman, Lokman Hakim

    2016-01-01

    Background Understanding different patterns of fish consumption is an important component for risk assessment of contaminants in fish. A few studies on food consumption had been conducted in Malaysia, but none of them focused specifically on fish consumption. The objectives of this study were to document the meal pattern among three major ethnics in Malaysia with respect to fish/seafood consumption, identify most frequently consumed fish and cooking method, and examine the influence of demographic factors on pattern of fish consumption among study subjects. Methods A cross-sectional survey was conducted between February 2008 and May 2009 to investigate patterns of fish consumption among Malaysian adults in Peninsular Malaysia. Adults aged 18 years and above were randomly selected and fish consumption data were collected using a 3-day prospective food diary. Results A total of 2,675 subjects, comprising male (44.2%) and female (55.7%) participants from major ethnics (Malays, 76.9%; Chinese, 14.7%; Indians, 8.3%) with a mean age of 43.4±16.2 years, were involved in this study. The results revealed 10 most frequently consumed marine fish in descending order: Indian mackerel, anchovy, yellowtail and yellow-stripe scads, tuna, sardines, torpedo scad, Indian and short-fin scads, pomfret, red snapper, and king mackerel. Prawn and squid were also among the most preferred seafood by study subjects. The most frequently consumed freshwater fish were freshwater catfish and snakehead. The most preferred cooking style by Malaysians was deep-fried fish, followed by fish cooked in thick and/or thin chili gravy, fish curry, and fish cooked with coconut milk mixed with other spices and flavorings. Overall, Malaysians consumed 168 g/day fish, with Malay ethnics’ (175±143 g/day) consumption of fish significantly (p<0.001) higher compared with the other two ethnic groups (Chinese=152±133 g/day, Indians=136±141 g/day). Conclusion Fish consumption was significantly associated with

  16. Sex change and effective population size: implications for population genetic studies in marine fish.

    PubMed

    Coscia, I; Chopelet, J; Waples, R S; Mann, B Q; Mariani, S

    2016-10-01

    Large variance in reproductive success is the primary factor that reduces effective population size (Ne) in natural populations. In sequentially hermaphroditic (sex-changing) fish, the sex ratio is typically skewed and biased towards the 'first' sex, while reproductive success increases considerably after sex change. Therefore, sex-changing fish populations are theoretically expected to have lower Ne than gonochorists (separate sexes), assuming all other parameters are essentially equal. In this study, we estimate Ne from genetic data collected from two ecologically similar species living along the eastern coast of South Africa: one gonochoristic, the 'santer' sea bream Cheimerius nufar, and one protogynous (female-first) sex changer, the 'slinger' sea bream Chrysoblephus puniceus. For both species, no evidence of genetic structuring, nor significant variation in genetic diversity, was found in the study area. Estimates of contemporary Ne were significantly lower in the protogynous species, but the same pattern was not apparent over historical timescales. Overall, our results show that sequential hermaphroditism may affect Ne differently over varying time frames, and that demographic signatures inferred from genetic markers with different inheritance modes also need to be interpreted cautiously, in relation to sex-changing life histories.

  17. Sex change and effective population size: implications for population genetic studies in marine fish.

    PubMed

    Coscia, I; Chopelet, J; Waples, R S; Mann, B Q; Mariani, S

    2016-10-01

    Large variance in reproductive success is the primary factor that reduces effective population size (Ne) in natural populations. In sequentially hermaphroditic (sex-changing) fish, the sex ratio is typically skewed and biased towards the 'first' sex, while reproductive success increases considerably after sex change. Therefore, sex-changing fish populations are theoretically expected to have lower Ne than gonochorists (separate sexes), assuming all other parameters are essentially equal. In this study, we estimate Ne from genetic data collected from two ecologically similar species living along the eastern coast of South Africa: one gonochoristic, the 'santer' sea bream Cheimerius nufar, and one protogynous (female-first) sex changer, the 'slinger' sea bream Chrysoblephus puniceus. For both species, no evidence of genetic structuring, nor significant variation in genetic diversity, was found in the study area. Estimates of contemporary Ne were significantly lower in the protogynous species, but the same pattern was not apparent over historical timescales. Overall, our results show that sequential hermaphroditism may affect Ne differently over varying time frames, and that demographic signatures inferred from genetic markers with different inheritance modes also need to be interpreted cautiously, in relation to sex-changing life histories. PMID:27507184

  18. Population level impacts of cooling water withdrawals on harvested fish stocks.

    PubMed

    Newbold, Stephen C; Iovanna, Rich

    2007-04-01

    Trillions of gallons are withdrawn every year from U.S. rivers, estuaries, lakes, and coastal waters to cool the turbines of power plants and other equipment in manufacturing facilities. In the process, large numbers of aquatic organisms die from entrainment into the plant or impingement against the outer portion of the intake structure. In this paper, we develop a generalized age-structured population model with density dependent survival of sub-adult age classes, and we use the model to perform a screening analysis of the effects of entrainment and impingement for 15 harvested fish stocks off the California and Atlantic coasts. Stock sizes are estimated to be depressed by entrainment and impingement by less than 1% in 10 of the 15 cases considered, between 1 and 3% in two cases, and between 20 and 80% in three cases. A variety of sensitivity analyses are conducted to evaluate the influence of several sources of model and parameter uncertainties. PMID:17438750

  19. A review of the effects of azole compounds in fish and their possible involvement in masculinization of wild fish populations.

    PubMed

    Matthiessen, Peter; Weltje, Lennart

    2015-05-01

    Endocrine-mediated effects in fish populations have been widely documented. Most attention has been focused on feminization caused by estrogenic substances, but this paper reviews evidence for the effects of a group of fungicides and pharmaceuticals, the azoles, which have been reported to cause masculinization in fish. The paper considers information from laboratory studies on the effects of azole compounds on fish endocrinology, and on the potential existence of such effects in wild fish. The occurrence of some azoles in effluents and surface waters has also been briefly reviewed. Under laboratory conditions, many azoles are able to cause masculinization or defeminization in fish by inhibition of the P450 enzyme aromatase (CYP19). However, in no case where such effects have been observed in the field has a link been established with this group of substances. In most instances, other more convincing explanations have been proposed. Peak concentrations of some azoles in surface waters can approach those which, under continuous long-term exposure in the laboratory, might lead to some aromatase inhibition. However, available data on exposure and effects provide reassurance that the concentrations of azoles found in surface waters are too low to cause adverse effects in fish by interference with their endocrine system. Compared to the widespread observations of feminization and estrogenic effects in (male) fish, there are relatively few papers describing masculinization or defeminization in (female) wild fish populations, suggesting that this is quite a rare phenomenon. The significance of this result is emphasized by the fact that fish are among the best studied organisms in the environment. PMID:25899164

  20. A review of the effects of azole compounds in fish and their possible involvement in masculinization of wild fish populations.

    PubMed

    Matthiessen, Peter; Weltje, Lennart

    2015-05-01

    Endocrine-mediated effects in fish populations have been widely documented. Most attention has been focused on feminization caused by estrogenic substances, but this paper reviews evidence for the effects of a group of fungicides and pharmaceuticals, the azoles, which have been reported to cause masculinization in fish. The paper considers information from laboratory studies on the effects of azole compounds on fish endocrinology, and on the potential existence of such effects in wild fish. The occurrence of some azoles in effluents and surface waters has also been briefly reviewed. Under laboratory conditions, many azoles are able to cause masculinization or defeminization in fish by inhibition of the P450 enzyme aromatase (CYP19). However, in no case where such effects have been observed in the field has a link been established with this group of substances. In most instances, other more convincing explanations have been proposed. Peak concentrations of some azoles in surface waters can approach those which, under continuous long-term exposure in the laboratory, might lead to some aromatase inhibition. However, available data on exposure and effects provide reassurance that the concentrations of azoles found in surface waters are too low to cause adverse effects in fish by interference with their endocrine system. Compared to the widespread observations of feminization and estrogenic effects in (male) fish, there are relatively few papers describing masculinization or defeminization in (female) wild fish populations, suggesting that this is quite a rare phenomenon. The significance of this result is emphasized by the fact that fish are among the best studied organisms in the environment.

  1. Spatial Stability of Adult Aedes aegypti Populations

    PubMed Central

    Barrera, Roberto

    2011-01-01

    Vector control programs could be more efficient by identifying the location of highly productive sites of Aedes aegypti. This study explored if the number of female adults of Ae. aegypti in BG-Sentinel traps was clustered and if their spatial distribution changed in time in two neighborhoods in San Juan, Puerto Rico. Traps were uniformly distributed across each neighborhood (130 m from each other), and samples were taken every 3 weeks. Global and local spatial autocorrelations were explored. Spatial stability existed if the rank order of trap captures was kept in time. There was lack of global autocorrelation in both neighborhoods, precluding their stratification for control purposes. Hot and cold spots were identified, revealing the highly focal nature of Ae. aegypti. There was significant spatial stability throughout the study in both locations. The consistency in trap productivity in time could be used to increase the effectiveness of vector and dengue control programs. PMID:22144449

  2. Development of a spatially distributed model of fish population density for habitat assessment of rivers

    NASA Astrophysics Data System (ADS)

    Sui, Pengzhe; Iwasaki, Akito; Ryo, Masahiro; Saavedra, Oliver; Yoshimura, Chihiro

    2013-04-01

    Flow conditions play an important role in sustaining biodiversity of river ecosystem. However, their relations to freshwater fishes, especially to fish population density, have not been clearly described. This study, therefore, aimed to propose a new methodology to quantitatively link habitat conditions, including flow conditions and other physical conditions, to population density of fish species. We developed a basin-scale fish distribution model by integrating the concept of habitat suitability assessment with a distributed hydrological model (DHM) in order to estimate fish population density with particular attention to flow conditions. Generalized linear model (GLM) was employed to evaluate the relationship between population density of fish species and major environmental factors. The target basin was Sagami River in central Japan, where the river reach was divided into 10 sections by estuary, confluences of tributaries, and river-crossing structures (dams, weirs). The DHM was employed to simulate river discharge from 1998 to 2005, which was used to calculate 10 flow indices including mean discharge, 25th and 75th percentile discharge, duration of low and high flows, number of floods. In addition, 5 water quality parameters and 13 other physical conditions (such as basin area, river width, mean diameter of riverbed material, and number of river-crossing structures upstream and downstream) of each river section were considered as environmental variables. In case of Sagami River, 10 habitat variables among them were then selected based on their correlations to avoid multicollinearity. Finally, the best GLM was developed for each species based on Akaike's information criterion. As results, population densities of 16 fish species in Sagami River were modelled, and correlation coefficients between observed and calculated population densities for 10 species were more than 0.70. The key habitat factors for population density varied among fish species. Minimum

  3. Foodborne Trematode Metacercariae in Fish from Northern Vietnam and Their Adults Recovered from Experimental Hamsters

    PubMed Central

    Chai, Jong-Yil; De, Nguyen Van

    2012-01-01

    The prevalence of foodborne trematode (FBT) metacercariae was investigated in fish from 2 localities of northern Vietnam in 2004-2005. Freshwater fish (9 species) were collected from local markets in Hanoi City (n=76) and Nam Dinh Province (n=79), and were examined for FBT metacercariae using the artificial digestion technique. Adult flukes were obtained from hamsters experimentally infected with the metacercariae at day 8 post-infection. Three (Haplorchis pumilio, Centrocestus formosanus, and Procerovum varium) and 6 (Haplorchis taichui, H. pumilio, C. formosanus, P. varium, Stellantchasmus falcatus, and Heterophyopsis continua) species of FBT metacercariae were detected in the 2 regions, respectively. Overall, among the positive fish species, H. pumilio metacercariae were detected in 104 (80.0%) of 130 fish examined (metacercarial density per infected fish; 64.2). C. formosanus metacercariae were found in 37 (40.2%) of 92 fish (metacercarial density; 14.7). P. varium metacercariae were detected in 19 (63.3%) of 30 fish (Anabas testudineus and Mugil cephalus) (metacercarial density; 247.7). S. falcatus metacercariae were found in all 10 M. cephalus examined (metacercarial density; 84.4). H. continua metacercariae (2 in number) were detected in 1 fish of Coilia lindmani. Morphologic characteristics of the FBT metacercariae and their experimentally obtained adults were described. The results have demonstrated that various FBT species are prevalent in northen parts of Vietnam. PMID:23230329

  4. Measles, mumps, rubella and chickenpox in the adult population.

    PubMed

    Boodley, C A; Jaquis, J L

    1989-02-01

    The common "childhood diseases" of measles, mumps, rubella and chickenpox do appear in the adult population. It is important for health care practitioners to recognize these diseases in adults and be alert for possible complications which may be more serious than those found in children. This article discusses epidemiology, transmission, signs and symptoms, treatment, possible complications, confirmatory tests and immunization recommendations for each of the four diseases.

  5. Management of fish populations in large rivers: a review of tools and approaches

    USGS Publications Warehouse

    Petts, Geoffrey E.; Imhoff, Jack G.; Manny, Bruce A.; Maher, John F. B.; Weisberg, Stephen B.

    1989-01-01

    In common with most branches of science, the management of riverine fish populations is characterised by reductionist and isolationist philosophies. Traditional fish management focuses on stocking and controls on fishing. This paper presents a concensus of scientists involved in the LARS workshop on the management of fish populations in large rivers. A move towards a more holistic philosophy is advocated, with fish management forming an integral part of sustainable river development. Based upon a questionnaire survey of LARS members, with wide-ranging expertise and experience from all parts of the world, lists of management tools currently in use are presented. Four categories of tools are described: flow, water-quality, habitat, and biological. The potential applications of tools for fish management in large rivers is discussed and research needs are identified. The lack of scientific evaluations of the different tools remains the major constraint to their wider application.

  6. MODELING THE RESPONSE OF FISH POPULATIONS TO EUTROPHICATION

    EPA Science Inventory

    Eutrophication resulting from nonpoint source pollution is one of the largest environmental problems in lakes and reservoirs around the world. Two characteristics of eutrophication, decreased dissolved oxygen and increased concentration of ammonia, are known to affect fishes, yet...

  7. Climate change effects on North American inland fish populations and assemblages

    USGS Publications Warehouse

    Lynch, Abigail J.; Myers, Bonnie; Chu, Cindy; Eby, Lisa A.; Falke, Jeffrey A.; Kovach, Ryan P.; Krabbenhoft, Trevor J.; Kwak, Thomas J.; Lyons, John; Paukert, Craig P.; Whitney, James E.

    2016-01-01

    Climate is a critical driver of many fish populations, assemblages, and aquatic communities. However, direct observational studies of climate change impacts on North American inland fishes are rare. In this synthesis, we (1) summarize climate trends that may influence North American inland fish populations and assemblages, (2) compile 31 peer-reviewed studies of documented climate change effects on North American inland fish populations and assemblages, and (3) highlight four case studies representing a variety of observed responses ranging from warmwater systems in the southwestern and southeastern United States to coldwater systems along the Pacific Coast and Canadian Shield. We conclude by identifying key data gaps and research needs to inform adaptive, ecosystem-based approaches to managing North American inland fishes and fisheries in a changing climate.

  8. Using passive acoustic telemetry to infer mortality events in adult herbivorous coral reef fishes

    NASA Astrophysics Data System (ADS)

    Khan, J. A.; Welsh, J. Q.; Bellwood, D. R.

    2016-06-01

    Mortality is considered to be an important factor shaping the structure of coral reef fish communities, but data on the rate and nature of mortality of adult coral reef fishes are sparse. Mortality on coral reefs is intrinsically linked with predation, with most evidence suggesting that predation is highest during crepuscular periods. We tested this hypothesis using passive acoustic telemetry data to determine the time of day of potential mortality events (PMEs) of adult herbivorous reef fishes. A total of 94 fishes were tagged with acoustic transmitters, of which 43 exhibited a PME. Furthermore, we identified five categories of PMEs based on the nature of change in acoustic signal detections from tagged fishes. The majority of PMEs were characterised by an abrupt stop in detections, possibly as a result of a large, mobile predator. Overall, mortality rates were estimated to be approximately 59 % per year using passive acoustic telemetry. The time of day of PMEs suggests that predation was highest during the day and crepuscular periods and lowest at night, offering only partial support for the crepuscular predation hypothesis. Visually oriented, diurnal and crepuscular predators appear to be more important than their nocturnal counterparts in terms of predation on adult reef fishes. By timing PMEs, passive acoustic telemetry may offer an important new tool for investigating the nature of predation on coral reefs.

  9. Density-dependent processes in the life history of fishes: evidence from laboratory populations of zebrafish Danio rerio.

    PubMed

    Hazlerigg, Charles R E; Lorenzen, Kai; Thorbek, Pernille; Wheeler, James R; Tyler, Charles R

    2012-01-01

    Population regulation is fundamental to the long-term persistence of populations and their responses to harvesting, habitat modification, and exposure to toxic chemicals. In fish and other organisms with complex life histories, regulation may involve density dependence in different life-stages and vital rates. We studied density dependence in body growth and mortality through the life-cycle of laboratory populations of zebrafish Danio rerio. When feed input was held constant at population-level (leading to resource limitation), body growth was strongly density-dependent in the late juvenile and adult phases of the life-cycle. Density dependence in mortality was strong during the early juvenile phase but declined thereafter and virtually ceased prior to maturation. Provision of feed in proportion to individual requirements (easing resource limitation) removed density dependence in growth and substantially reduced density dependence in mortality, thus indicating that 'bottom-up' effects act on growth as well as mortality, but most strongly on growth. Both growth and mortality played an important role in population regulation, with density-dependent growth having the greater impact on population biomass while mortality had the greatest impact on numbers. We demonstrate a clear ontogenic pattern of change in density-dependent processes within populations of a very small (maximum length 5 mm) fish, maintained in constant homogeneous laboratory conditions. The patterns are consistent with those distilled from studies on wild fish populations, indicating the presence of broad ontogenic patterns in density-dependent processes that are invariant to maximum body size and hold in homogeneous laboratory, as well as complex natural environments. PMID:22655056

  10. Ecosystem context for estimating stress-induced reductions in fish populations

    SciTech Connect

    Bartell, S.M. )

    1990-01-01

    Methods are described for extrapolating acute toxicity data to expected effects of toxic substances on fish populations in pelagic ecosystems. The methods are based on a physiological process equation for fish growth; the equation was modified to express sublethal toxic effects. The methods are exemplified by an estimation of the risks posed to fish populations by chloroparaffins, risk being defined as the probability of observing a specified decrease in annual fish production. At exposure concentrations as low as 0.01-0.05 mg chloroparaffins/L, the risks of a 25 or 50% decrease in annual piscivore production were approximately 1.0. Analysis of 2,500 chloroparaffin simulations showed that indirect food web effects were a primary cause of modeled reductions in fish populations. The effects of phenol on production of largemouth bass Micropterus salmoides that were predicted by the ecosystem risk methods were compared with effects predicted by a largemouth bass population model. Both models predicted minimal effects at low exposures and severe mortality at high exposure concentrations. At intermediate exposures, the ecosystem model predicted more severe population reductions than did the population model. The model results demonstrated that ecosystem processes, not accounted for in laboratory toxicity assays, can strongly influence the effects of chemical stress on fish populations.

  11. Sublethal exposure to crude oil during embryonic development alters cardiac morphology and reduces aerobic capacity in adult fish

    PubMed Central

    Hicken, Corinne E.; Linbo, Tiffany L.; Baldwin, David H.; Willis, Maryjean L.; Myers, Mark S.; Holland, Larry; Larsen, Marie; Stekoll, Michael S.; Rice, Stanley D.; Collier, Tracy K.; Scholz, Nathaniel L.; Incardona, John P.

    2011-01-01

    Exposure to high concentrations of crude oil produces a lethal syndrome of heart failure in fish embryos. Mortality is caused by cardiotoxic polycyclic aromatic hydrocarbons (PAHs), ubiquitous components of petroleum. Here, we show that transient embryonic exposure to very low concentrations of oil causes toxicity that is sublethal, delayed, and not counteracted by the protective effects of cytochrome P450 induction. Nearly a year after embryonic oil exposure, adult zebrafish showed subtle changes in heart shape and a significant reduction in swimming performance, indicative of reduced cardiac output. These delayed physiological impacts on cardiovascular performance at later life stages provide a potential mechanism linking reduced individual survival to population-level ecosystem responses of fish species to chronic, low-level oil pollution. PMID:21482755

  12. Vulnerability and diet breadth predict larval and adult parasite diversity in fish of the Bothnian Bay.

    PubMed

    Locke, Sean A; Marcogliese, David J; Valtonen, E Tellervo

    2014-01-01

    Recent studies of aquatic food webs show that parasite diversity is concentrated in nodes that likely favour transmission. Various aspects of parasite diversity have been observed to be correlated with the trophic level, size, diet breadth, and vulnerability to predation of hosts. However, no study has attempted to distinguish among all four correlates, which may have differential importance for trophically transmitted parasites occurring as larvae or adults. We searched for factors that best predict the diversity of larval and adult endoparasites in 4105 fish in 25 species studied over a three-year period in the Bothnian Bay, Finland. Local predator-prey relationships were determined from stomach contents, parasites, and published data in 8,229 fish in 31 species and in seals and piscivorous birds. Fish that consumed more species of prey had more diverse trophically transmitted adult parasites. Larval parasite diversity increased with the diversity of both prey and predators, but increases in predator diversity had a greater effect. Prey diversity was more strongly associated with the diversity of adult parasites than with that of larvae. The proportion of parasite species present as larvae in a host species was correlated with the diversity of its predators. There was a notable lack of association with the diversity of any parasite guild and fish length, trophic level, or trophic category. Thus, diversity is associated with different nodal properties in larval and adult parasites, and association strengths also differ, strongly reflecting the life cycles of parasites and the food chains they follow to complete transmission.

  13. Estimating Consumption to Biomass Ratio in Non-Stationary Harvested Fish Populations

    PubMed Central

    Wiff, Rodrigo; Roa-Ureta, Ruben H.; Borchers, David L.; Milessi, Andrés C.; Barrientos, Mauricio A.

    2015-01-01

    The food consumption to biomass ratio (C) is one of the most important population parameters in ecosystem modelling because its quantifies the interactions between predator and prey. Existing models for estimating C in fish populations are per-recruit cohort models or empirical models, valid only for stationary populations. Moreover, empirical models lack theoretical support. Here we develop a theory and derive a general modelling framework to estimate C in fish populations, based on length frequency data and the generalised von Bertalanffy growth function, in which models for stationary populations with a stable-age distributions are special cases. Estimates using our method are compared with estimates from per-recruit cohort models for C using simulated harvested fish populations of different lifespans. The models proposed here are also applied to three fish populations that are targets of commercial fisheries in southern Chile. Uncertainty in the estimation of C was evaluated using a resampling approach. Simulations showed that stationary and non-stationary population models produce different estimates for C and those differences depend on the lifespan, fishing mortality and recruitment variations. Estimates of C using the new model exhibited smoother inter-annual variation in comparison with a per-recruit model estimates and they were also smaller than C predicted by the empirical equations in all population assessed. PMID:26528721

  14. Estimating Consumption to Biomass Ratio in Non-Stationary Harvested Fish Populations.

    PubMed

    Wiff, Rodrigo; Roa-Ureta, Ruben H; Borchers, David L; Milessi, Andrés C; Barrientos, Mauricio A

    2015-01-01

    The food consumption to biomass ratio (C) is one of the most important population parameters in ecosystem modelling because its quantifies the interactions between predator and prey. Existing models for estimating C in fish populations are per-recruit cohort models or empirical models, valid only for stationary populations. Moreover, empirical models lack theoretical support. Here we develop a theory and derive a general modelling framework to estimate C in fish populations, based on length frequency data and the generalised von Bertalanffy growth function, in which models for stationary populations with a stable-age distributions are special cases. Estimates using our method are compared with estimates from per-recruit cohort models for C using simulated harvested fish populations of different lifespans. The models proposed here are also applied to three fish populations that are targets of commercial fisheries in southern Chile. Uncertainty in the estimation of C was evaluated using a resampling approach. Simulations showed that stationary and non-stationary population models produce different estimates for C and those differences depend on the lifespan, fishing mortality and recruitment variations. Estimates of C using the new model exhibited smoother inter-annual variation in comparison with a per-recruit model estimates and they were also smaller than C predicted by the empirical equations in all population assessed.

  15. PREDICTING THE OCCURRANCE OF ADAPTATION TO DIOXINLIKE COMPOUNDS IN POPULATIONS OF THE ESTUARINE FISH FUNDULUS HETEROCLITUS

    EPA Science Inventory

    A population of the non-migratory estuarine fish species Fundulus heteroclitus (mummichog) indigenous to a polychlorinated biphenyl (PCB)-contaminated Superfund site (New Bedford Harbor, NBH, MA, USA) demonstrates an inherited tolerance to local, dioxin-like contaminants (DLCs). ...

  16. Population Variation in the Life History of a Land Fish, Alticus arnoldorum, and the Effects of Predation and Density

    PubMed Central

    Platt, Edward R. M.; Ord, Terry J.

    2015-01-01

    Life history variation can often reflect differences in age-specific mortality within populations, with the general expectation that reproduction should be shifted away from ages experiencing increased mortality. Investigators of life history in vertebrates frequently focus on the impact of predation, but there is increasing evidence that predation may have unexpected impacts on population density that in turn prompt unexpected changes in life history. There are also other reasons why density might impact life history independently of predation or mortality more generally. We investigated the consequences of predation and density on life history variation among populations of the Pacific leaping blenny, Alticus arnoldorum. This fish from the island of Guam spends its adult life out of the water on rocks in the splash zone, where it is vulnerable to predation and can be expected to be sensitive to changes in population density that impact resource availability. We found populations invested more in reproduction as predation decreased, while growth rate varied primarily in response to population density. These differences in life history among populations are likely plastic given the extensive gene flow among populations revealed by a previous study. The influence of predation and density on life history was unlikely to have operated independently of each other, with predation rate tending to be associated with reduced population densities. Taken together, our results suggest predation and density can have complex influences on life history, and that plastic life history traits could allow populations to persist in new or rapidly changing environments. PMID:26398191

  17. Population Variation in the Life History of a Land Fish, Alticus arnoldorum, and the Effects of Predation and Density.

    PubMed

    Platt, Edward R M; Ord, Terry J

    2015-01-01

    Life history variation can often reflect differences in age-specific mortality within populations, with the general expectation that reproduction should be shifted away from ages experiencing increased mortality. Investigators of life history in vertebrates frequently focus on the impact of predation, but there is increasing evidence that predation may have unexpected impacts on population density that in turn prompt unexpected changes in life history. There are also other reasons why density might impact life history independently of predation or mortality more generally. We investigated the consequences of predation and density on life history variation among populations of the Pacific leaping blenny, Alticus arnoldorum. This fish from the island of Guam spends its adult life out of the water on rocks in the splash zone, where it is vulnerable to predation and can be expected to be sensitive to changes in population density that impact resource availability. We found populations invested more in reproduction as predation decreased, while growth rate varied primarily in response to population density. These differences in life history among populations are likely plastic given the extensive gene flow among populations revealed by a previous study. The influence of predation and density on life history was unlikely to have operated independently of each other, with predation rate tending to be associated with reduced population densities. Taken together, our results suggest predation and density can have complex influences on life history, and that plastic life history traits could allow populations to persist in new or rapidly changing environments.

  18. Population Variation in the Life History of a Land Fish, Alticus arnoldorum, and the Effects of Predation and Density.

    PubMed

    Platt, Edward R M; Ord, Terry J

    2015-01-01

    Life history variation can often reflect differences in age-specific mortality within populations, with the general expectation that reproduction should be shifted away from ages experiencing increased mortality. Investigators of life history in vertebrates frequently focus on the impact of predation, but there is increasing evidence that predation may have unexpected impacts on population density that in turn prompt unexpected changes in life history. There are also other reasons why density might impact life history independently of predation or mortality more generally. We investigated the consequences of predation and density on life history variation among populations of the Pacific leaping blenny, Alticus arnoldorum. This fish from the island of Guam spends its adult life out of the water on rocks in the splash zone, where it is vulnerable to predation and can be expected to be sensitive to changes in population density that impact resource availability. We found populations invested more in reproduction as predation decreased, while growth rate varied primarily in response to population density. These differences in life history among populations are likely plastic given the extensive gene flow among populations revealed by a previous study. The influence of predation and density on life history was unlikely to have operated independently of each other, with predation rate tending to be associated with reduced population densities. Taken together, our results suggest predation and density can have complex influences on life history, and that plastic life history traits could allow populations to persist in new or rapidly changing environments. PMID:26398191

  19. Estimated Full Scale IQ in an Adult Heroin Addict Population.

    ERIC Educational Resources Information Center

    Chastain, Robert L.; And Others

    The research concerning intellectual functioning in addict populations has not addressed basic questions concerning why and how intelligence quotients (IQ) might be related to drug addiction. A study was undertaken to estimate intellectual functioning based upon a demographic profile for Wechsler Adult Intelligence Scale-Revised (WAIS-R) Full…

  20. Evaluation of Juvenile Fish Bypass and Adult Fish Passage Facilities at Water Diversions on the Umatilla River; 1994 Annual Report.

    SciTech Connect

    Knapp, Suzanne M.

    1995-01-01

    We report on our progress from October 1993 through September 1994 in evaluating juvenile salmonid bypass facilities and juvenile salmonid passage through ladder facilities, and investigating passage conditions for juvenile fish at diversion dam facilities on the lower Umatilla River in northeastern Oregon. We also report on our progress in evaluating adult salmonid passage at and between dams on the lower Umatilla River and upriver migration using radio telemetry. Two principal studies are also included. Report A (ODFW): To evaluate the juvenile salmonid bypass facilities a Feed and Furnish canals, juvenile salmonid passage through fish ladders at Stanfield, Feed Canal, Westland, and Three Mile Falls dams, and the juvenile salmonid trap and haul procedures at Westland Canal. To investigate passage conditions at all passage facilities. Report B (CTUIR): To examine the passage of adult salmonids past diversions in the lower Umatilla River and their movement in the upper river after transport, using radio telemetry, and to assess factors for successful homing. These studies are part of a program to rehabilitate anadromous fish stocks in the Umatilla River Basin, including restoration of coho salmon (Oncorhynchus kisutch) and chinook salmon (Oncorhynchus tshawytscha), as well as enhancement of summer steelhead (Oncorhynchus mykiss).

  1. Adaptation to sea level rise: does local adaptation influence the demography of coastal fish populations?

    PubMed

    Purcell, K M; Klerks, P L; Leberg, P L

    2010-10-01

    This study compared the growth of two western mosquitofish Gambusia affinis populations that were previously demonstrated to have genetic adaptations that increased survival under lethal salinity exposures. The objective was to evaluate how genetic adaptations to lethal salinity stress affect population demography when exposed to sublethal salinity stress. Results indicate that chronic salinity exposure had a generally negative impact on population size, but fish originating from one of the two populations established with fish from a brackish site exhibited an increase in population size. Saltwater intrusion seems to result in reduced population size for most populations. Some populations inhabiting more saline sites, however, may develop localized adaptations, mitigating the consequences of increased salinity on population productivity. PMID:21039500

  2. Genotypic structure of a Drosophila population for adult locomotor activity

    SciTech Connect

    Grechanyi, G.V.; Korzun, V.M.

    1995-01-01

    Analysis of the variation of adult locomotor activity in four samples taken at different times from a natural population of Drosophila melanogaster showed that the total variation of this trait is relatively stable in time and has a substantial genetic component. Genotypic structure of the population for locomotor activity is characterized by the presence of large groups of genotypes with high and low values of this trait. A possible explanation for the presence of such groups in a population is cyclic density-dependent selection.

  3. Deleterious effects in mice of fish-associated methylmercury contained in a diet mimicking the Western populations' average fish consumption.

    PubMed

    Bourdineaud, Jean-Paul; Fujimura, Masatake; Laclau, Muriel; Sawada, Masumi; Yasutake, Akira

    2011-02-01

    Methylmercury (MeHg) is a potent neurotoxin, and human beings are mainly exposed to this pollutant through fish consumption. Only a few contradictory epidemiological studies are currently available examining the impact of fish consumption on human populations. In the present study, we wanted to address whether a diet mimicking the fish consumption of Western populations could result in observable adverse effects in mice, and whether beneficial nutriments from fish were able to counterbalance the deleterious effects of MeHg, if any. In Europe and the United States, fish consumption varies widely between countries, from 11 to 100 g fish/day. A mid-range value of 25 g fish/day corresponds to a fish contribution to the total diet of 1.25% on a dry weight basis. We decided to supplement a vegetarian-based mouse diet with 1.25% of lyophilized salmon flesh (SAL diet), or 1.25% of a blend of lyophilized cod, tuna, and swordfish (CTS diet). Total mercury contents were 1.15±0.15, 2.3±0.1 and 35.75±0.15 ng Hg/g of food pellets for the control, SAL and CTS diets, respectively. After two months feeding, the CTS diet resulted in significant observable effects as compared to the control and SAL diets, encompassing decreased body growth, altered behavioral performance and increased anxiety level, modification of mitochondrial respiratory protein subunit concentrations in kidney and brain structures, modified gene expression patterns in kidneys, liver and muscles, and a decrease of dopamine concentrations in the hypothalamus and striatum. Our findings have health implications, firstly because 1.25% of CTS flesh in the diet corresponds to an average exposure to MeHg below the WHO provisory tolerable weekly intake (PTWI) (1.6 μg MeHg/kg of body weight/week), and secondly because many people in Western populations, among them women of child-bearing age, are exceeding the PTWI value (for instance, 35% of the French population inhabiting the Atlantic and Mediterranean coasts). PMID

  4. Effects of stream acidification and habitat on fish populations of a North American river

    USGS Publications Warehouse

    Baldigo, Barry P.; Lawrence, G.B.

    2001-01-01

    Water quality, physical habitat, and fisheries at sixteen reaches in the Neversink River Basin were studied during 1991-95 to identify the effects of acidic precipitation on stream-water chemistry and on selected fish-species populations, and to test the hypothesis that the degree of stream acidification affected the spatial distribution of each fish-species population. Most sites on the East Branch Neversink were strongly to severely acidified, whereas most sites on the West Branch were minimally to moderately acidified. Mean density of fish populations ranged from 0 to 2.15 fish/m2; biomass ranged from 0 to 17.5 g/m2. Where brook trout were present, their population density ranged from 0.04 to 1.09 fish/m2, biomass ranged from 0.76 to 12.2 g/m2, and condition (K) ranged from 0.94 to 1.07. Regression analyses revealed strong relations (r2 ?? 0.41 to 0.99; p ??? 0.05) between characteristics of the two most common species (brook trout and slimy sculpin) populations and mean concentrations of inorganic monomeric aluminum (Alim), pH, Si, K+, NO3/-, NH4/+, DOC, Ca2+, and Na+; acid neutralizing capacity (ANC); and water temperature. Stream acidification may have adversely affected fish populations at most East Branch sites, but in other parts of the Neversink River Basin these effects were masked or mitigated by other physical habitat, geochemical, and biological factors.

  5. Variation in aggressive behaviour in the poeciliid fish Brachyrhaphis episcopi: population and sex differences.

    PubMed

    Archard, Gabrielle A; Braithwaite, Victoria A

    2011-01-01

    Aggression is often positively correlated with other behavioural traits such as boldness and activity levels. Comparisons across populations can help to determine factors that promote the evolution of such traits. We quantified these behaviours by testing the responses of wild-caught poeciliid fish, Brachyrhaphis episcopi, to mirror image stimuli. This species occurs in populations that experience either high or low levels of predation pressure. Previous studies have shown that B. episcopi from low predation environments are less bold than those that occur with many predators. We therefore predicted that fish from high predation populations would be more aggressive and more active than fish from low predation populations. However, we found the opposite - low predation fish approached a mirror and a novel object more frequently than high predation fish suggesting that 'boldness' and aggression were higher in low predation populations, and that population-level boldness measures may vary depending on context. When tested individually, low predation fish inspected their mirror image more frequently. Females, but not males, from low predation sites were also more aggressive towards their mirror image. Variation in female aggression may be driven by a trade-off between food availability and predation risk. This suggests that the relationship between aggression and boldness has been shaped by adaptation to environmental conditions, and not genetic constraints.

  6. STREAM FISH HABITAT SUITABILITY AND THE RISK OF POPULATION DECLINE

    EPA Science Inventory

    Over half of the streams in the Mid-Atlantic Highlands have fish communities that are in fair or poor condition, and the EPA concluded that physical habitat alteration represents the greatest potential stressor across this region. A quantitative method for relating habitat quali...

  7. Sampling characteristics and calibration of snorkel counts to estimate stream fish populations

    USGS Publications Warehouse

    Weaver, D.; Kwak, Thomas J.; Pollock, Kenneth

    2014-01-01

    Snorkeling is a versatile technique for estimating lotic fish population characteristics; however, few investigators have evaluated its accuracy at population or assemblage levels. We evaluated the accuracy of snorkeling using prepositioned areal electrofishing (PAE) for estimating fish populations in a medium-sized Appalachian Mountain river during fall 2008 and summer 2009. Strip-transect snorkel counts were calibrated with PAE counts in identical locations among macrohabitats, fish species or taxa, and seasons. Mean snorkeling efficiency (i.e., the proportion of individuals counted from the true population) among all taxa and seasons was 14.7% (SE, 2.5%), and the highest efficiencies were for River Chub Nocomis micropogon at 21.1% (SE, 5.9%), Central Stoneroller Campostoma anomalum at 20.3% (SE, 9.6%), and darters (Percidae) at 17.1% (SE, 3.7%), whereas efficiencies were lower for shiners (Notropis spp., Cyprinella spp., Luxilus spp.) at 8.2% (SE, 2.2%) and suckers (Catostomidae) at 6.6% (SE, 3.2%). Macrohabitat type, fish taxon, or sampling season did not significantly explain variance in snorkeling efficiency. Mean snorkeling detection probability (i.e., probability of detecting at least one individual of a taxon) among fish taxa and seasons was 58.4% (SE, 6.1%). We applied the efficiencies from our calibration study to adjust snorkel counts from an intensive snorkeling survey conducted in a nearby reach. Total fish density estimates from strip-transect counts adjusted for snorkeling efficiency were 7,288 fish/ha (SE, 1,564) during summer and 15,805 fish/ha (SE, 4,947) during fall. Precision of fish density estimates is influenced by variation in snorkeling efficiency and sample size and may be increased with additional sampling effort. These results demonstrate the sampling properties and utility of snorkeling to characterize lotic fish assemblages with acceptable efficiency and detection probability, less effort, and no mortality, compared with traditional

  8. Importance of floodplain connectivity to fish populations in the Apalachicola River, Florida

    USGS Publications Warehouse

    Burgess, O.T.; Pine, William E.; Walsh, S.J.

    2013-01-01

    Floodplain habitats provide critical spawning and rearing habitats for many large-river fishes. The paradigm that floodplains are essential habitats is often a key reason for restoring altered rivers to natural flow regimes. However, few studies have documented spatial and temporal utilization of floodplain habitats by adult fish of sport or commercial management interest or assessed obligatory access to floodplain habitats for species' persistence. In this study, we applied telemetry techniques to examine adult fish movements between floodplain and mainstem habitats, paired with intensive light trap sampling of larval fish in these same habitats, to assess the relationships between riverine flows and fish movement and spawning patterns in restored and unmodified floodplain distributaries of the Apalachicola River, Florida. Our intent is to inform resource managers on the relationships between the timing, magnitude and duration of flow events and fish spawning as part of river management actions. Our results demonstrate spawning by all study species in floodplain and mainstem river habitat types, apparent migratory movements of some species between these habitats, and distinct spawning events for each study species on the basis of fish movement patterns and light trap catches. Additionally, Micropterus spp., Lepomis spp. and, to a lesser degree, Minytrema melanops used floodplain channel habitat that was experimentally reconnected to the mainstem within a few weeks of completing the restoration. This result is of interest to managers assessing restoration activities to reconnect these habitats as part of riverine restoration programmes globally.

  9. Estimating mortality rates of adult fish from entrainment through the propellers of river towboats

    USGS Publications Warehouse

    Gutreuter, S.; Dettmers, J.M.; Wahl, David H.

    2003-01-01

    We developed a method to estimate mortality rates of adult fish caused by entrainment through the propellers of commercial towboats operating in river channels. The method combines trawling while following towboats (to recover a fraction of the kills) and application of a hydrodynamic model of diffusion (to estimate the fraction of the total kills collected in the trawls). The sampling problem is unusual and required quantifying relatively rare events. We first examined key statistical properties of the entrainment mortality rate estimators using Monte Carlo simulation, which demonstrated that a design-based estimator and a new ad hoc estimator are both unbiased and converge to the true value as the sample size becomes large. Next, we estimated the entrainment mortality rates of adult fishes in Pool 26 of the Mississippi River and the Alton Pool of the Illinois River, where we observed kills that we attributed to entrainment. Our estimates of entrainment mortality rates were 2.52 fish/km of towboat travel (80% confidence interval, 1.00-6.09 fish/km) for gizzard shad Dorosoma cepedianum, 0.13 fish/km (0.00-0.41) for skipjack herring Alosa chrysochloris, and 0.53 fish/km (0.00-1.33) for both shovelnose sturgeon Scaphirhynchus platorynchus and smallmouth buffalo Ictiobus bubalus. Our approach applies more broadly to commercial vessels operating in confined channels, including other large rivers and intracoastal waterways.

  10. Consequences of the size structure of fish populations for their effects on a generalist avian predator.

    PubMed

    Kloskowski, Janusz

    2011-06-01

    Size-structured interspecific interactions can shift between predation and competition, depending on ontogenetic changes in size relationships. I examined the effects of common carp (Cyprinus carpio), an omnivorous fish, on the reproductive success of the red-necked grebe (Podiceps grisegena), an avian gape-limited predator, along a fish size gradient created by stocking distinct age-cohorts in seminatural ponds. Young-of-the-year (0+) carp were an essential food source for young grebes. Only adult birds were able to consume 1-year-old (1+) fish, while 2-year-old (2+) fish attained a size refuge from grebes. Amphibian larvae were the principal alternative prey to fish, followed by macroinvertebrates, but the abundance of both dramatically decreased along the carp size gradient. Fledging success was 2.8 times greater in ponds with 0+ versus 1+ carp; in ponds with 1+ carp, chicks received on average 2.6-3 times less prey biomass from their parents, and over 1/3 of broods suffered total failure. Breeding birds avoided settling on 2+ ponds. These results show that changes in prey fish size structure can account for shifts from positive trophic effects on the avian predator to a negative impact on the predator's alternative resources. However, competition did not fully explain the decrease in grebe food resources in the presence of large fish, as carp and grebes overlapped little in diet. In experimental cages, 1+ carp totally eliminated young larvae of amphibians palatable to fish. In field conditions, breeding adults of palatable taxa avoided ponds with 1+ and older carp. Non-trophic interactions such as habitat selection by amphibians or macroinvertebrates to avoid large fish may provide an indirect mechanism strengthening the adverse bottom-up effects of fish on birds.

  11. Space-time investigation of the effects of fishing on fish populations.

    PubMed

    Ono, Kotaro; Shelton, Andrew O; Ward, Eric J; Thorson, James T; Feist, Blake E; Hilborn, Ray

    2016-03-01

    Species distribution models (SDMs) are important statistical tools for obtaining ecological insight into species-habitat relationships and providing advice for natural resource management. Many SDMs have been developed over the past decades, with a focus on space- and more recently, time-dependence. However, most of these studies have been on terrestrial species and applications to marine species have been limited. In this study, we used three large spatio-temporal data sources (habitat maps, survey-based fish density estimates, and fishery catch data) and a novel space-time model to study how the distribution of fishing may affect the seasonal dynamics of a commercially important fish species (Pacific Dover sole, Microstomus pacificus) off the west coast of the USA. Dover sole showed a large scale change in seasonal and annual distribution of biomass, and its distribution shifted from mid-depth zones to inshore or deeper waters during late summer/early fall. In many cases, the scale of fishery removal was small compared to these broader changes in biomass, suggesting that seasonal dynamics were primarily driven by movement and not by fishing. The increasing availability of appropriate data and space-time modeling software should facilitate extending this work to many other species, particularly those in marine ecosystems, and help tease apart the role of growth, natural mortality, recruitment, movement, and fishing on spatial patterns of species distribution in marine systems. PMID:27209782

  12. Space-time investigation of the effects of fishing on fish populations.

    PubMed

    Ono, Kotaro; Shelton, Andrew O; Ward, Eric J; Thorson, James T; Feist, Blake E; Hilborn, Ray

    2016-03-01

    Species distribution models (SDMs) are important statistical tools for obtaining ecological insight into species-habitat relationships and providing advice for natural resource management. Many SDMs have been developed over the past decades, with a focus on space- and more recently, time-dependence. However, most of these studies have been on terrestrial species and applications to marine species have been limited. In this study, we used three large spatio-temporal data sources (habitat maps, survey-based fish density estimates, and fishery catch data) and a novel space-time model to study how the distribution of fishing may affect the seasonal dynamics of a commercially important fish species (Pacific Dover sole, Microstomus pacificus) off the west coast of the USA. Dover sole showed a large scale change in seasonal and annual distribution of biomass, and its distribution shifted from mid-depth zones to inshore or deeper waters during late summer/early fall. In many cases, the scale of fishery removal was small compared to these broader changes in biomass, suggesting that seasonal dynamics were primarily driven by movement and not by fishing. The increasing availability of appropriate data and space-time modeling software should facilitate extending this work to many other species, particularly those in marine ecosystems, and help tease apart the role of growth, natural mortality, recruitment, movement, and fishing on spatial patterns of species distribution in marine systems.

  13. Dissection of complex adult traits in a mouse synthetic population.

    PubMed

    Burke, David T; Kozloff, Kenneth M; Chen, Shu; West, Joshua L; Wilkowski, Jodi M; Goldstein, Steven A; Miller, Richard A; Galecki, Andrzej T

    2012-08-01

    Finding the causative genetic variations that underlie complex adult traits is a significant experimental challenge. The unbiased search strategy of genome-wide association (GWAS) has been used extensively in recent human population studies. These efforts, however, typically find only a minor fraction of the genetic loci that are predicted to affect variation. As an experimental model for the analysis of adult polygenic traits, we measured a mouse population for multiple phenotypes and conducted a genome-wide search for effector loci. Complex adult phenotypes, related to body size and bone structure, were measured as component phenotypes, and each subphenotype was associated with a genomic spectrum of candidate effector loci. The strategy successfully detected several loci for the phenotypes, at genome-wide significance, using a single, modest-sized population (N = 505). The effector loci each explain 2%-10% of the measured trait variation and, taken together, the loci can account for over 25% of a trait's total population variation. A replicate population (N = 378) was used to confirm initially observed loci for one trait (femur length), and, when the two groups were merged, the combined population demonstrated increased power to detect loci. In contrast to human population studies, our mouse genome-wide searches find loci that individually explain a larger fraction of the observed variation. Also, the additive effects of our detected mouse loci more closely match the predicted genetic component of variation. The genetic loci discovered are logical candidates for components of the genetic networks having evolutionary conservation with human biology. PMID:22588897

  14. Linking temporal changes in the demographic structure and individual growth to the decline in the population of a tropical fish

    NASA Astrophysics Data System (ADS)

    Sirot, Charlotte; Darnaude, Audrey M.; Guilhaumon, François; Ramos-Miranda, Julia; Flores-Hernandez, Domingo; Panfili, Jacques

    2015-11-01

    The exceptional biodiversity and productivity of tropical coastal lagoons can only be preserved by identifying the causes for the decline in the populations living in these vulnerable ecosystems. The Terminos lagoon in Mexico provided an opportunity for studying this issue as some of its fish populations, in particular the Silver Perch (Bairdiella chrysoura), have declined significantly since the 1980s. Fish sampling campaigns carried out over the whole lagoon area in 1979-81 and again in 2006-2011 revealed the mechanisms which may have been responsible for this decline. Based on biometrical data for 295 juveniles and adults from the two periods and on somatic growth derived from 173 otoliths, a study of the temporal changes in the demographic structure and life history traits (individual growth and body condition) made it possible to distinguish the causes of the decline in the B. chrysoura population. Growth models for the lagoon in 1980-1981 and 2006-2011 showed no significant change in the growth parameters of the population over the last 30 years with a logistic model giving an accurate estimate (R2 = 0.66) of the size-at-age for both periods. The decline in the B. chrysoura population could not be explained by an overall decrease in individual size and condition in the lagoon, the average standard length (SL) and Fulton index (FI) having increased slightly since 1980-1981 (4.6 mm and 0.02 for juveniles and 5.42 mm and 0.07 for adults). However, the size structure of the population in the lagoon has changed, with a significant shift in the size distribution of juveniles with a marked reduction in the proportion of juveniles ≤ 60 mm in the captures (90.9% fewer than in 1980-1981). As the otolith growth rate of fish during the first 4 months also decreased significantly between the two sampling periods (-15%), it is suggested that the main reason for the decline in the abundance and biomass of B. chrysoura within this system may be that its habitats are less

  15. Fishery-Independent Data Reveal Negative Effect of Human Population Density on Caribbean Predatory Fish Communities

    PubMed Central

    Stallings, Christopher D.

    2009-01-01

    Background Understanding the current status of predatory fish communities, and the effects fishing has on them, is vitally important information for management. However, data are often insufficient at region-wide scales to assess the effects of extraction in coral reef ecosystems of developing nations. Methodology/Principal Findings Here, I overcome this difficulty by using a publicly accessible, fisheries-independent database to provide a broad scale, comprehensive analysis of human impacts on predatory reef fish communities across the greater Caribbean region. Specifically, this study analyzed presence and diversity of predatory reef fishes over a gradient of human population density. Across the region, as human population density increases, presence of large-bodied fishes declines, and fish communities become dominated by a few smaller-bodied species. Conclusions/Significance Complete disappearance of several large-bodied fishes indicates ecological and local extinctions have occurred in some densely populated areas. These findings fill a fundamentally important gap in our knowledge of the ecosystem effects of artisanal fisheries in developing nations, and provide support for multiple approaches to data collection where they are commonly unavailable. PMID:19421312

  16. Physiological responses of adult rainbow trout experimentally released through a unique fish conveyance device

    USGS Publications Warehouse

    Mesa, Matthew G.; Gee, Lisa P.; Weiland, Lisa K.; Christiansen, Helena E.

    2013-01-01

    We assessed the physiological stress responses (i.e., plasma levels of cortisol, glucose, and lactate) of adult Rainbow Trout Oncorhynchus mykiss at selected time intervals after they had passed a distance of 15 m through a unique fish conveyance device (treatment fish) or not (controls). This device differs from traditional fish pumps in two important ways: (1) it transports objects in air, rather than pumping them from and with water; and (2) it uses a unique tube for transport that has a series of soft, deformable baffles spaced evenly apart and situated perpendicular within a rigid, but flexible outer shell. Mean concentrations of the plasma constituents never differed (P > 0.05) between control and treatment fish at 0, 1, 4, 8, or 24 h after passage, and only minor differences were apparent between the different time intervals within a group. We observed no obvious injuries on any of our fish. Our results indicate that passage through this device did not severely stress or injure fish and it may allow for the rapid and safe movement of fish at hatcheries, sorting or handling facilities, or passage obstacles.

  17. Length-based assessment of coral reef fish populations in the main and northwestern Hawaiian islands.

    PubMed

    Nadon, Marc O; Ault, Jerald S; Williams, Ivor D; Smith, Steven G; DiNardo, Gerard T

    2015-01-01

    The coral reef fish community of Hawaii is composed of hundreds of species, supports a multimillion dollar fishing and tourism industry, and is of great cultural importance to the local population. However, a major stock assessment of Hawaiian coral reef fish populations has not yet been conducted. Here we used the robust indicator variable "average length in the exploited phase of the population ([Formula: see text])", estimated from size composition data from commercial fisheries trip reports and fishery-independent diver surveys, to evaluate exploitation rates for 19 Hawaiian reef fishes. By and large, the average lengths obtained from diver surveys agreed well with those from commercial data. We used the estimated exploitation rates coupled with life history parameters synthesized from the literature to parameterize a numerical population model and generate stock sustainability metrics such as spawning potential ratios (SPR). We found good agreement between predicted average lengths in an unfished population (from our population model) and those observed from diver surveys in the largely unexploited Northwestern Hawaiian Islands. Of 19 exploited reef fish species assessed in the main Hawaiian Islands, 9 had SPRs close to or below the 30% overfishing threshold. In general, longer-lived species such as surgeonfishes, the redlip parrotfish (Scarus rubroviolaceus), and the gray snapper (Aprion virescens) had the lowest SPRs, while short-lived species such as goatfishes and jacks, as well as two invasive species (Lutjanus kasmira and Cephalopholis argus), had SPRs above the 30% threshold. PMID:26267473

  18. Length-Based Assessment of Coral Reef Fish Populations in the Main and Northwestern Hawaiian Islands

    PubMed Central

    Nadon, Marc O.; Ault, Jerald S.; Williams, Ivor D.; Smith, Steven G.; DiNardo, Gerard T.

    2015-01-01

    The coral reef fish community of Hawaii is composed of hundreds of species, supports a multimillion dollar fishing and tourism industry, and is of great cultural importance to the local population. However, a major stock assessment of Hawaiian coral reef fish populations has not yet been conducted. Here we used the robust indicator variable “average length in the exploited phase of the population (L¯)”, estimated from size composition data from commercial fisheries trip reports and fishery-independent diver surveys, to evaluate exploitation rates for 19 Hawaiian reef fishes. By and large, the average lengths obtained from diver surveys agreed well with those from commercial data. We used the estimated exploitation rates coupled with life history parameters synthesized from the literature to parameterize a numerical population model and generate stock sustainability metrics such as spawning potential ratios (SPR). We found good agreement between predicted average lengths in an unfished population (from our population model) and those observed from diver surveys in the largely unexploited Northwestern Hawaiian Islands. Of 19 exploited reef fish species assessed in the main Hawaiian Islands, 9 had SPRs close to or below the 30% overfishing threshold. In general, longer-lived species such as surgeonfishes, the redlip parrotfish (Scarus rubroviolaceus), and the gray snapper (Aprion virescens) had the lowest SPRs, while short-lived species such as goatfishes and jacks, as well as two invasive species (Lutjanus kasmira and Cephalopholis argus), had SPRs above the 30% threshold. PMID:26267473

  19. Ocean Acidification Effects on Atlantic Cod Larval Survival and Recruitment to the Fished Population.

    PubMed

    Stiasny, Martina H; Mittermayer, Felix H; Sswat, Michael; Voss, Rüdiger; Jutfelt, Fredrik; Chierici, Melissa; Puvanendran, Velmurugu; Mortensen, Atle; Reusch, Thorsten B H; Clemmesen, Catriona

    2016-01-01

    How fisheries will be impacted by climate change is far from understood. While some fish populations may be able to escape global warming via range shifts, they cannot escape ocean acidification (OA), an inevitable consequence of the dissolution of anthropogenic carbon dioxide (CO2) emissions in marine waters. How ocean acidification affects population dynamics of commercially important fish species is critical for adapting management practices of exploited fish populations. Ocean acidification has been shown to impair fish larvae's sensory abilities, affect the morphology of otoliths, cause tissue damage and cause behavioural changes. Here, we obtain first experimental mortality estimates for Atlantic cod larvae under OA and incorporate these effects into recruitment models. End-of-century levels of ocean acidification (~1100 μatm according to the IPCC RCP 8.5) resulted in a doubling of daily mortality rates compared to present-day CO2 concentrations during the first 25 days post hatching (dph), a critical phase for population recruitment. These results were consistent under different feeding regimes, stocking densities and in two cod populations (Western Baltic and Barents Sea stock). When mortality data were included into Ricker-type stock-recruitment models, recruitment was reduced to an average of 8 and 24% of current recruitment for the two populations, respectively. Our results highlight the importance of including vulnerable early life stages when addressing effects of climate change on fish stocks.

  20. Length-based assessment of coral reef fish populations in the main and northwestern Hawaiian islands.

    PubMed

    Nadon, Marc O; Ault, Jerald S; Williams, Ivor D; Smith, Steven G; DiNardo, Gerard T

    2015-01-01

    The coral reef fish community of Hawaii is composed of hundreds of species, supports a multimillion dollar fishing and tourism industry, and is of great cultural importance to the local population. However, a major stock assessment of Hawaiian coral reef fish populations has not yet been conducted. Here we used the robust indicator variable "average length in the exploited phase of the population ([Formula: see text])", estimated from size composition data from commercial fisheries trip reports and fishery-independent diver surveys, to evaluate exploitation rates for 19 Hawaiian reef fishes. By and large, the average lengths obtained from diver surveys agreed well with those from commercial data. We used the estimated exploitation rates coupled with life history parameters synthesized from the literature to parameterize a numerical population model and generate stock sustainability metrics such as spawning potential ratios (SPR). We found good agreement between predicted average lengths in an unfished population (from our population model) and those observed from diver surveys in the largely unexploited Northwestern Hawaiian Islands. Of 19 exploited reef fish species assessed in the main Hawaiian Islands, 9 had SPRs close to or below the 30% overfishing threshold. In general, longer-lived species such as surgeonfishes, the redlip parrotfish (Scarus rubroviolaceus), and the gray snapper (Aprion virescens) had the lowest SPRs, while short-lived species such as goatfishes and jacks, as well as two invasive species (Lutjanus kasmira and Cephalopholis argus), had SPRs above the 30% threshold.

  1. Ocean Acidification Effects on Atlantic Cod Larval Survival and Recruitment to the Fished Population.

    PubMed

    Stiasny, Martina H; Mittermayer, Felix H; Sswat, Michael; Voss, Rüdiger; Jutfelt, Fredrik; Chierici, Melissa; Puvanendran, Velmurugu; Mortensen, Atle; Reusch, Thorsten B H; Clemmesen, Catriona

    2016-01-01

    How fisheries will be impacted by climate change is far from understood. While some fish populations may be able to escape global warming via range shifts, they cannot escape ocean acidification (OA), an inevitable consequence of the dissolution of anthropogenic carbon dioxide (CO2) emissions in marine waters. How ocean acidification affects population dynamics of commercially important fish species is critical for adapting management practices of exploited fish populations. Ocean acidification has been shown to impair fish larvae's sensory abilities, affect the morphology of otoliths, cause tissue damage and cause behavioural changes. Here, we obtain first experimental mortality estimates for Atlantic cod larvae under OA and incorporate these effects into recruitment models. End-of-century levels of ocean acidification (~1100 μatm according to the IPCC RCP 8.5) resulted in a doubling of daily mortality rates compared to present-day CO2 concentrations during the first 25 days post hatching (dph), a critical phase for population recruitment. These results were consistent under different feeding regimes, stocking densities and in two cod populations (Western Baltic and Barents Sea stock). When mortality data were included into Ricker-type stock-recruitment models, recruitment was reduced to an average of 8 and 24% of current recruitment for the two populations, respectively. Our results highlight the importance of including vulnerable early life stages when addressing effects of climate change on fish stocks. PMID:27551924

  2. Ocean Acidification Effects on Atlantic Cod Larval Survival and Recruitment to the Fished Population

    PubMed Central

    Stiasny, Martina H.; Mittermayer, Felix H.; Sswat, Michael; Voss, Rüdiger; Jutfelt, Fredrik; Chierici, Melissa; Puvanendran, Velmurugu; Mortensen, Atle; Reusch, Thorsten B. H.; Clemmesen, Catriona

    2016-01-01

    How fisheries will be impacted by climate change is far from understood. While some fish populations may be able to escape global warming via range shifts, they cannot escape ocean acidification (OA), an inevitable consequence of the dissolution of anthropogenic carbon dioxide (CO2) emissions in marine waters. How ocean acidification affects population dynamics of commercially important fish species is critical for adapting management practices of exploited fish populations. Ocean acidification has been shown to impair fish larvae’s sensory abilities, affect the morphology of otoliths, cause tissue damage and cause behavioural changes. Here, we obtain first experimental mortality estimates for Atlantic cod larvae under OA and incorporate these effects into recruitment models. End-of-century levels of ocean acidification (~1100 μatm according to the IPCC RCP 8.5) resulted in a doubling of daily mortality rates compared to present-day CO2 concentrations during the first 25 days post hatching (dph), a critical phase for population recruitment. These results were consistent under different feeding regimes, stocking densities and in two cod populations (Western Baltic and Barents Sea stock). When mortality data were included into Ricker-type stock-recruitment models, recruitment was reduced to an average of 8 and 24% of current recruitment for the two populations, respectively. Our results highlight the importance of including vulnerable early life stages when addressing effects of climate change on fish stocks. PMID:27551924

  3. Orthodontic treatment need in a Spanish young adult population

    PubMed Central

    Montiel-Company, José M.; Manzanera-Pastor, David; Almerich-Silla, José M.

    2012-01-01

    Objectives: Orthodontic treatment need has often been assessed in child populations, but few studies employing internationally-recognized indices have been conducted in adult or young adult populations. The aim of this study was to determine the orthodontic treatment need of a young adult population in Spain by means of the Dental Aesthetic Index (DAI), the Index of Orthodontic Treatment Need (IOTN) and the need perceived by the patients. Study design: A cross-sectional epidemiological study was conducted in a broad, representative sample of 671 adults aged between 35 and 44 years using health centers in the Valencia Region of Spain, following the recommendations of the World Health Organization (WHO). Results: Orthodontic treatment was required by 31.3% of the sample according to the DAI and 19.2% according to the IOTN (DHC). The orthodontic treatment need perceived by the patients was 21.1%. On relating treatment need to different variables, significant differences in patient perception were encountered by gender, as women perceived a greater need (23.9%) than men (14.4%). Significant differences in previous orthodontic treatment history were found between middle/high (15%) and low (9%) social class and between secondary/tertiary (14%) and primary (3.3%) education. Conclusions: There was no agreement between the treatment need assessed objectively by the indices and that perceived by the patient, or between the indices themselves. The decision to undergo orthodontic treatment can depend on socioeconomic and psychological factors and on values and principles that do not easily lend themselves to objective measurement. Key words:Orthodontics, epidemiology, adult, malocclusion. PMID:22322504

  4. Assessing risks to fish populations near a proposed disposal facility for used nuclear fuel

    SciTech Connect

    Hart, D.; Miesenheimer, P.; Hull, R.

    1995-12-31

    The concept of used nuclear fuel disposal in the Canadian Shield is currently undergoing a federal environmental assessment review process. As part of this review, potential risks to brook trout populations in the vicinity of such an underground repository were considered. Chemical fate, transport and exposure models have been utilized to estimate the dose rates from released radionuclides and other fuel constituents, and these likely will not be sufficient to harm fish in nearby streams. However, other stressors such as habitat alteration (e.g., loss of upwelling) and/or fishing pressure associated with increased public access could have significant population impacts if the site is located in a pristine northern region. Population models are utilized to explore the risks of local population reduction for different combinations of fishing pressure and habitat degradation.

  5. Tidal management sffects sub-adult fish assemblages in impounded South Carolina Marshes

    USGS Publications Warehouse

    Carswell, Ben L.; Peterson, James T.; Jennings, Cecil A.

    2015-01-01

    In coastal South Carolina, most impounded marshes are managed for waterfowl; fewer are managed for fishes. Tidal control is central to each strategy but raises concerns that nursery function could be impaired. This research examined the assemblage composition of fishes during early-life stages. We sampled two impoundments of each management type monthly in 2008 and 2009. We used light traps to collect 61,527 sub-adult fish representing 21 species and 16 families and push nets to collect 12,670 sub-adult fish representing 13 species and 11 families. The effective number of species detected at larval stage in “fish” impoundments (summer mean = 2.52 ± 0.20, winter mean = 2.02 ± 0.66) was greater than in “waterfowl” impoundments (summer mean = 1.27 ± 0.14, winter mean = 1.06 ± 0.09); CI = 90 %. Species richness did not differ between management types, but hierarchical linear models predicted differences in assemblage composition. These findings underscore the importance of frequent water exchange for maintaining diverse assemblages of early-life-stage fishes in marsh impoundments.

  6. Recovery in the health of fish populations and communities following remedial activities at a bleached kraft mill facility

    SciTech Connect

    Greeley, M.S. Jr.; Adams, S.M.; Saylor, C.F.

    1995-12-31

    Fish populations and communities were studied over a seven year period in a river receiving bleached kraft mill effluent (BKME). The period of these investigations preceded and accompanied the extensive modernization of mill facilities and the implementation of design changes to reduce contaminant discharges and minimize impacts on the river ecology. Before modernization, reaches of the river downstream of the discharges were characterized by depauperate fish communities and severely skewed population distributions. The relative condition of both individual fish and fish populations in the river prior to remediation was consistent with effects frequently attributed to exposure to endocrine disrupting agents, including a sex ratio strongly skewed towards male fish, alterations in reproductive hormone levels, pronounced atresia of the developing oocytes in female fish, and a general absence of young fish suggesting near total reproductive failure in a sentinel fish population. Following modernization, sex ratios have trended towards normality, young fish have returned to the mainstream river, and fish communities have become more diverse coincident with corresponding decreases in body burdens of dioxin and other indirect indicators of contaminant exposure, including liver detoxification enzyme activity. The significance of these studies lie in the establishment of distinct links between both: (1) the exposure of individual wild fish to BKME and alterations in fish population and community structure, and (2) the implementation of process changes in a mill producing BKME and noticeable improvements in fish health from the individual to community levels of biological organization.

  7. Fish population losses from Adirondack Lakes: The role of surface water acidity and acidification

    NASA Astrophysics Data System (ADS)

    Baker, Joan P.; Warren-Hicks, William J.; Gallagher, James; Christensen, Sigurd W.

    1993-04-01

    Changes over time in the species composition of fish communities in Adirondack lakes were assessed to determine (1) the approximate numbers offish populations that have been lost and (2) the degree to which fish population losses may have resulted from surface water acidification and acidic deposition. Information on the present-day status offish communities was obtained by the Adirondack Lakes Survey Corporation, which surveyed 1469 Adirondack lakes in 1984-1987 (53% of the total ponded waters in the Adirondack ecological zone). Two hundred and ninety-five of these lakes had been surveyed in 1929-1934 during the first statewide biological survey; 720 had been surveyed in one or more years prior to 1970. Sixteen to 19% of the lakes with adequate historical data appeared to have lost one or more fish populations as a result of acidification. Brook trout and acid-sensitive minnow species had experienced the most widespread effects. Populations of brook trout and acid-sensitive minnows had been lost apparently as a result of acidification from 11% and 19%, respectively, of the lakes with confirmed historical occurrence of these taxa. By contrast, fish species that tend to occur primarily in lower elevation and larger lakes, such as largemouth and smallmouth bass and brown trout, have experienced little to no documented adverse effects. Lakes that were judged to have lost fish populations as a result of acidification had significantly lower; pH and, in most cases, also had higher estimated concentrations of inorganic aluminum and occurred at higher elevations than did lakes with the fish species still present. No other lake characteristics were consistently associated with fish population losses attributed to acidification. The exact numbers and proportions of fish populations affected could not be determined because of limitations on the quantity and quality of historical data. Lakes for which we had adequate historical data to assess long-term trends in fish

  8. Evaluation of Juvenile Fish Bypass and Adult Fish Passage Facilities at Three-Mile Falls Dam; Umatilla River, Oregon, 1989 Annual Report.

    SciTech Connect

    Nigro, Anthony A.

    1990-09-01

    We report on our progress from October 1989 through September 1990 on evaluating juvenile fish bypass and adult fish passage facilities at Three Mile Falls Dam on the Umatilla River. The study is a cooperative effort by the Oregon Department of Fish and Wildlife (ODFW) and the Confederated Tribes of the Umatilla Indian Reservation (CTUIR). Study objectives addressed by ODFW and CTUIR are: (1) ODFW (Report A): Operate and evaluate the juvenile fish bypass system in the West Extension Irrigation District canal at Three Mile Falls Dam; and (2) CTUIR (Report 8): Examine the passage of adult salmonids at Three Mile Falls Dam. The study is part of a program to rehabilitate anadromous fish stocks in the Umatilla River Basin that includes restorations of coho salmon Oncorhynchus Wsutch and chinook salmon 0. tshawytscha and enhancement of summer steelhead 0. mytiss.

  9. Putting pharmaceuticals into the wider context of challenges to fish populations in rivers

    PubMed Central

    Johnson, Andrew C.; Sumpter, John P.

    2014-01-01

    The natural range of fish species in our rivers is related to flow, elevation, temperature, local habitat and connectivity. For over 2000 years, humans have altered to varying degrees the river habitat. In the past 200 years, we added to the environmental disruption by discharging poorly treated sewage, nutrients and industrial waste into our rivers. For many rivers, the low point arrived during the period of 1950s–1970s, when rapid economic development overrode environmental concerns and dissolved oxygen concentrations dropped to zero. In these more enlightened times, gross river pollution is a thing of the past in the Developed World. However, persistent legacy chemical contaminants can be found in fish long after their discharge ceased. Changes in habitat quality and morphology caused and continue to cause the disappearance of fish species. The range of fish stressors has now increased as temperatures rise, and non-native fish introductions bring new diseases. The threat from pharmaceuticals to fish populations remains hypothetical, and no studies have yet linked change in fish populations to exposure. PMID:25405969

  10. Contaminant effects on Great Lakes' fish-eating birds: a population perspective

    USGS Publications Warehouse

    Heinz, G.H.; Kendall, Ronald J.; Dickerson, Richard L.; Giesy, John P.; Suk, William P.

    1998-01-01

    Preventing environmental contaminants from reducing wildlife populations is the greatest concern in wildlife toxicology. In the Great Lakes, environmental contaminants have a history of reducing populations of many species of fish-eating birds. Endocrine effects may have contributed to declines in fish-eating bird populations, but the overriding harm was caused by DDE-induced eggshell thinning. Toxic effects may still be occurring today, but apparently they are not of a sufficient magnitude to depress populations of most fish-eating birds. Once DDE levels in the Great Lakes declined, eggshells of birds began to get thicker and reproductive success improved. Populations of double-crested cormorants (Phalacrocorax auritus) and ring-billed gulls (Larus delawarensis) have increased dramatically since the bans on DDT and other organochlorine pesticides. Bald eagles (Haliaeetus leucocephalus) are still not reproducing at a normal rate along the shores of the Great Lakes, but success is much improved compared to earlier records when eggshell thinning was worse. Other species, such as herring gulls (Larus argentatus) and black-crowned night-herons (Nycticorax nycticorax), seem to be having improved reproductive success, but data on Great Lakes'-wide population changes are incomplete. Reproductive success of common terns (Sterna hirundo), Caspian terns (Sterna caspia), and Forster's terns (Sterna forsteri) seems to have improved in recent years, but, again, data on population changes are not very complete, and these birds face many habitat related problems as well as contaminant problems. Although contaminants are still producing toxic effects, and these effects may include endocrine disfunction, fish-eating birds in the Great Lakes seem to be largely weathering these effects, at least as far as populations are concerned. A lack of obvious contaminant effects on populations of fish-eating birds in the Great Lakes, however, should not be equated with a lack of any harm to

  11. High intake of fatty fish, but not of lean fish, affects serum concentrations of TAG and HDL-cholesterol in healthy, normal-weight adults: a randomised trial.

    PubMed

    Hagen, Ingrid V; Helland, Anita; Bratlie, Marianne; Brokstad, Karl A; Rosenlund, Grethe; Sveier, Harald; Mellgren, Gunnar; Gudbrandsen, Oddrun A

    2016-08-01

    The aim of the present study was to examine whether high intake of lean or fatty fish (cod and farmed salmon, respectively) by healthy, normal-weight adults would affect risk factors of type 2 diabetes and CVD when compared with lean meat (chicken). More knowledge is needed concerning the potential health effects of high fish intake (>300 g/week) in normal-weight adults. In this randomised clinical trial, thirty-eight young, healthy, normal-weight participants consumed 750 g/week of lean or fatty fish or lean meat (as control) for 4 weeks at dinner according to provided recipes to ensure similar ways of preparations and choices of side dishes between the groups. Energy and macronutrient intakes at baseline and end point were similar in all groups, and there were no changes in energy and macronutrient intakes within any of the groups during the course of the study. High intake of fatty fish, but not lean fish, significantly reduced TAG and increased HDL-cholesterol concentrations in fasting serum when compared with lean meat intake. When compared with lean fish intake, fatty fish intake increased serum HDL-cholesterol. No differences were observed between lean fish, fatty fish and lean meat groups regarding fasting and postprandial glucose regulation. These findings suggest that high intake of fatty fish, but not of lean fish, could beneficially affect serum concentrations of TAG and HDL-cholesterol, which are CVD risk factors, in healthy, normal-weight adults, when compared with high intake of lean meat. PMID:27363518

  12. High intake of fatty fish, but not of lean fish, affects serum concentrations of TAG and HDL-cholesterol in healthy, normal-weight adults: a randomised trial.

    PubMed

    Hagen, Ingrid V; Helland, Anita; Bratlie, Marianne; Brokstad, Karl A; Rosenlund, Grethe; Sveier, Harald; Mellgren, Gunnar; Gudbrandsen, Oddrun A

    2016-08-01

    The aim of the present study was to examine whether high intake of lean or fatty fish (cod and farmed salmon, respectively) by healthy, normal-weight adults would affect risk factors of type 2 diabetes and CVD when compared with lean meat (chicken). More knowledge is needed concerning the potential health effects of high fish intake (>300 g/week) in normal-weight adults. In this randomised clinical trial, thirty-eight young, healthy, normal-weight participants consumed 750 g/week of lean or fatty fish or lean meat (as control) for 4 weeks at dinner according to provided recipes to ensure similar ways of preparations and choices of side dishes between the groups. Energy and macronutrient intakes at baseline and end point were similar in all groups, and there were no changes in energy and macronutrient intakes within any of the groups during the course of the study. High intake of fatty fish, but not lean fish, significantly reduced TAG and increased HDL-cholesterol concentrations in fasting serum when compared with lean meat intake. When compared with lean fish intake, fatty fish intake increased serum HDL-cholesterol. No differences were observed between lean fish, fatty fish and lean meat groups regarding fasting and postprandial glucose regulation. These findings suggest that high intake of fatty fish, but not of lean fish, could beneficially affect serum concentrations of TAG and HDL-cholesterol, which are CVD risk factors, in healthy, normal-weight adults, when compared with high intake of lean meat.

  13. Is fishing selective for physiological and energetic characteristics in migratory adult sockeye salmon?

    PubMed

    Cooke, Steven J; Donaldson, Michael R; Hinch, Scott G; Crossin, Glenn T; Patterson, David A; Hanson, Kyle C; English, Karl K; Shrimpton, J Mark; Farrell, Anthony P

    2009-08-01

    There is extensive evidence that fishing is often selective for specific phenotypic characteristics, and that selective harvest can thus result in genotypic change. To date, however, there are no studies that evaluate whether fishing is selective for certain physiological or energetic characteristics that may influence fish behaviour and thus vulnerability to capture. Here, adult sockeye salmon (Oncorhynchus nerka) were used as a model to test the null hypothesis that fishing is not selective for specific physiological or energetic traits. Fish were intercepted during their spawning migrations, implanted with a gastric radio transmitter, and biopsied (i.e., non-lethally sampled for blood, gill tissue and quantification of energetic status). In both 2003 and 2006, we tagged and biopsied 301 and 770 sockeye salmon, respectively, in the marine environment en route to their natal river system to spawn. In 2006 an additional 378 individuals were tagged and biopsied in freshwater. We found that 23 (7.6%) of the marine fish tagged in 2003, 78 (10.1%) of the marine fish tagged in 2006 and 57 (15.1%) of the freshwater fish tagged in 2006 were harvested by one of three fisheries sectors that operate in the coastal marine environment and the Fraser River (i.e. commercial, recreational or First Nations fisheries between the site of release and Hell's Gate in the Fraser River, approximately 250 km upriver and 465 km from the ocean tagging site). However, fisheries were not open continually or consistently in different locations and for different fisheries sectors necessitating a paired analytical approach. As such, for statistical analyses we paired individual fish that were harvested with another fish of the same genetic stock that was released on the same date and exhibited similar migration behaviour, except that they successfully evaded capture and reached natal spawning grounds. Using two-tailed Wilcoxon matched pairs signed-rank tests, we revealed that the physiological

  14. Vicariance and dispersal across Baja California in disjunct marine fish populations.

    PubMed

    Bernardi, Giacomo; Findley, Lloyd; Rocha-Olivares, Axayacatl

    2003-07-01

    Population disjunctions, as a first step toward complete allopatry, present an interesting situation to study incipient speciation. The geological formation of the Baja California Peninsula currently divides 19 species of fish into disjunct populations that are found on its Pacific Coast and in the northern part of the Gulf of California (also called the Sea of Cortez), but are absent from the Cape (Cabo San Lucas) region. We studied the genetic makeup of disjunct populations for 12 of these 19 fish species. Phylogeographic patterns for the 12 species can be separated into two major classes: a first group (eight species) showed reciprocal monophyly and high genetic divergence between disjunct populations. A second group (four species) displayed what appeared to be panmictic populations. Population structure between Pacific Coast populations, across the Punta Eugenia biogeographic boundary, was also evaluated. While dispersal potential (inferred by pelagic larval duration) was a poor predictor of population structure between Gulf of California and Pacific populations, we found that population genetic subdivision along the Pacific Coast at Punta Eugenia was always positively correlated with differentiation between Pacific and Gulf of California populations. Vicariant events, ongoing gene flow, and ecological characteristics played essential roles in shaping the population structures observed in this study.

  15. Effects of Spearfishing on Reef Fish Populations in a Multi-Use Conservation Area

    PubMed Central

    Frisch, Ashley J.; Cole, Andrew J.; Hobbs, Jean-Paul A.; Rizzari, Justin R.; Munkres, Katherine P.

    2012-01-01

    Although spearfishing is a popular method of capturing fish, its ecological effects on fish populations are poorly understood, which makes it difficult to assess the legitimacy and desirability of spearfishing in multi-use marine reserves. Recent management changes within the Great Barrier Reef Marine Park (GBRMP) fortuitously created a unique scenario by which to quantify the effects of spearfishing on fish populations. As such, we employed underwater visual surveys and a before-after-control-impact experimental design to investigate the effects of spearfishing on the density and size structure of target and non-target fishes in a multi-use conservation park zone (CPZ) within the GBRMP. Three years after spearfishing was first allowed in the CPZ, there was a 54% reduction in density and a 27% reduction in mean size of coral trout (Plectropomus spp.), the primary target species. These changes were attributed to spearfishing because benthic habitat characteristics and the density of non-target fishes were stable through time, and the density and mean size of coral trout in a nearby control zone (where spearfishing was prohibited) remained unchanged. We conclude that spearfishing, like other forms of fishing, can have rapid and substantial negative effects on target fish populations. Careful management of spearfishing is therefore needed to ensure that conservation obligations are achieved and that fishery resources are harvested sustainably. This is particularly important both for the GBRMP, due to its extraordinarily high conservation value and world heritage status, and for tropical island nations where people depend on spearfishing for food and income. To minimize the effects of spearfishing on target species and to enhance protection of functionally important fishes (herbivores), we recommend that fishery managers adjust output controls such as size- and catch-limits, rather than prohibit spearfishing altogether. This will preserve the cultural and social

  16. [Prolonged fever: specific issues in the young adult population].

    PubMed

    Carmoi, T; Grateau, G; Billhot, M; Dumas, G; Biale, L; Perrot, G; Algayres, J-P

    2010-12-01

    Early studies on prolonged fever date back to the 1960s. Fifty years later, prolonged unexplained fever remains a diagnostic challenge to the general internists. Although the aetiologies of prolonged fevers have not changed much in the general population, the distribution between the various causes is not the same anymore. A regular decrease in infectious and neoplastic causes is noticed whatever the age. Prolonged fevers related to inflammatory disorders and fevers that remain of unknown origin still represent approximately 30 to 50% of the cases. In the young adult population, as in the older patients, prolonged fevers can be attributed to four groups: infection, inflammation, neoplasic and other aetiologies (including drug-related fevers). In the young adult population, the management of prolonged fever presents some specific issues that are the purpose of this review coupled with our own experience. The prognosis of undiagnosed prolonged fever is usually favourable, as a life-threatening aetiology is exceptionally diagnosed during the follow-up if the initial management was complete and accurate.

  17. It is the economy, stupid! Projecting the fate of fish populations using ecological-economic modeling.

    PubMed

    Quaas, Martin F; Reusch, Thorsten B H; Schmidt, Jörn O; Tahvonen, Olli; Voss, Rudi

    2016-01-01

    Four marine fish species are among the most important on the world market: cod, salmon, tuna, and sea bass. While the supply of North American and European markets for two of these species - Atlantic salmon and European sea bass - mainly comes from fish farming, Atlantic cod and tunas are mainly caught from wild stocks. We address the question what will be the status of these wild stocks in the midterm future, in the year 2048, to be specific. Whereas the effects of climate change and ecological driving forces on fish stocks have already gained much attention, our prime interest is in studying the effects of changing economic drivers, as well as the impact of variable management effectiveness. Using a process-based ecological-economic multispecies optimization model, we assess the future stock status under different scenarios of change. We simulate (i) technological progress in fishing, (ii) increasing demand for fish, and (iii) increasing supply of farmed fish, as well as the interplay of these driving forces under different scenarios of (limited) fishery management effectiveness. We find that economic change has a substantial effect on fish populations. Increasing aquaculture production can dampen the fishing pressure on wild stocks, but this effect is likely to be overwhelmed by increasing demand and technological progress, both increasing fishing pressure. The only solution to avoid collapse of the majority of stocks is institutional change to improve management effectiveness significantly above the current state. We conclude that full recognition of economic drivers of change will be needed to successfully develop an integrated ecosystem management and to sustain the wild fish stocks until 2048 and beyond. PMID:26348787

  18. It is the economy, stupid! Projecting the fate of fish populations using ecological-economic modeling.

    PubMed

    Quaas, Martin F; Reusch, Thorsten B H; Schmidt, Jörn O; Tahvonen, Olli; Voss, Rudi

    2016-01-01

    Four marine fish species are among the most important on the world market: cod, salmon, tuna, and sea bass. While the supply of North American and European markets for two of these species - Atlantic salmon and European sea bass - mainly comes from fish farming, Atlantic cod and tunas are mainly caught from wild stocks. We address the question what will be the status of these wild stocks in the midterm future, in the year 2048, to be specific. Whereas the effects of climate change and ecological driving forces on fish stocks have already gained much attention, our prime interest is in studying the effects of changing economic drivers, as well as the impact of variable management effectiveness. Using a process-based ecological-economic multispecies optimization model, we assess the future stock status under different scenarios of change. We simulate (i) technological progress in fishing, (ii) increasing demand for fish, and (iii) increasing supply of farmed fish, as well as the interplay of these driving forces under different scenarios of (limited) fishery management effectiveness. We find that economic change has a substantial effect on fish populations. Increasing aquaculture production can dampen the fishing pressure on wild stocks, but this effect is likely to be overwhelmed by increasing demand and technological progress, both increasing fishing pressure. The only solution to avoid collapse of the majority of stocks is institutional change to improve management effectiveness significantly above the current state. We conclude that full recognition of economic drivers of change will be needed to successfully develop an integrated ecosystem management and to sustain the wild fish stocks until 2048 and beyond.

  19. The influence of density on adults and juveniles of the estuarine fish, the sheepshead minnow (cyprinodon variegatus)

    EPA Science Inventory

    The relationship between population density and demographic rates (e.g. survival, reproduction, growth) is critical to understand population dynamics and has been widely studied in fishes. Estuarine species are regularly exposed to dramatic changes in density with daily, monthly,...

  20. An empirical model for estimating annual consumption by freshwater fish populations

    USGS Publications Warehouse

    Liao, H.; Pierce, C.L.; Larscheid, J.G.

    2005-01-01

    Population consumption is an important process linking predator populations to their prey resources. Simple tools are needed to enable fisheries managers to estimate population consumption. We assembled 74 individual estimates of annual consumption by freshwater fish populations and their mean annual population size, 41 of which also included estimates of mean annual biomass. The data set included 14 freshwater fish species from 10 different bodies of water. From this data set we developed two simple linear regression models predicting annual population consumption. Log-transformed population size explained 94% of the variation in log-transformed annual population consumption. Log-transformed biomass explained 98% of the variation in log-transformed annual population consumption. We quantified the accuracy of our regressions and three alternative consumption models as the mean percent difference from observed (bioenergetics-derived) estimates in a test data set. Predictions from our population-size regression matched observed consumption estimates poorly (mean percent difference = 222%). Predictions from our biomass regression matched observed consumption reasonably well (mean percent difference = 24%). The biomass regression was superior to an alternative model, similar in complexity, and comparable to two alternative models that were more complex and difficult to apply. Our biomass regression model, log10(consumption) = 0.5442 + 0.9962??log10(biomass), will be a useful tool for fishery managers, enabling them to make reasonably accurate annual population consumption predictions from mean annual biomass estimates. ?? Copyright by the American Fisheries Society 2005.

  1. Discrimination of fish populations using parasites: Random Forests on a 'predictable' host-parasite system.

    PubMed

    Pérez-Del-Olmo, A; Montero, F E; Fernández, M; Barrett, J; Raga, J A; Kostadinova, A

    2010-10-01

    We address the effect of spatial scale and temporal variation on model generality when forming predictive models for fish assignment using a new data mining approach, Random Forests (RF), to variable biological markers (parasite community data). Models were implemented for a fish host-parasite system sampled along the Mediterranean and Atlantic coasts of Spain and were validated using independent datasets. We considered 2 basic classification problems in evaluating the importance of variations in parasite infracommunities for assignment of individual fish to their populations of origin: multiclass (2-5 population models, using 2 seasonal replicates from each of the populations) and 2-class task (using 4 seasonal replicates from 1 Atlantic and 1 Mediterranean population each). The main results are that (i) RF are well suited for multiclass population assignment using parasite communities in non-migratory fish; (ii) RF provide an efficient means for model cross-validation on the baseline data and this allows sample size limitations in parasite tag studies to be tackled effectively; (iii) the performance of RF is dependent on the complexity and spatial extent/configuration of the problem; and (iv) the development of predictive models is strongly influenced by seasonal change and this stresses the importance of both temporal replication and model validation in parasite tagging studies.

  2. Compensatory mechanisms in fish populations: Literature reviews: Volume 1, Critical evaluation of case histories of fish populations experiencing chronic exploitation or impact: Final report

    SciTech Connect

    Saila, S.B.; Chen, X.; Erzini, K.; Martin, B.

    1987-05-01

    This study includes case histories of certain fish species which are experiencing chronic perturbations and related literature pertaining to compensation processes. ''Compensation'' has been defined as the ability of fish to offset the population reduction caused by natural or man-induced stresses. Certain compensation methods are widely accepted, and include cannibalism, competition, disease, growth and predation, among others. These compensation methods are examined in relation to each fish species included in the study. Stock-recruit relationships and empirical observations of changes in growth and mortality have been the focus of much of the background on compensation. One of the conclusions drawn from this study is that a significant amount of recruitment variability exists and can be attributed to environmental (rather than compensatory) factors. The stock-recruitment problem appears to be the most significant scientific problem related to compensation in the types of fish included in this study. Results of the most recent studies of the American shad support this theory. Life histories, breeding biology and other pertinent data relating to each species included in the study will be found in the appendices.

  3. Patterns of connectivity among populations of a coral reef fish

    NASA Astrophysics Data System (ADS)

    Chittaro, P. M.; Hogan, J. D.

    2013-06-01

    Knowledge of the patterns and scale of connectivity among populations is essential for the effective management of species, but our understanding is still poor for marine species. We used otolith microchemistry of newly settled bicolor damselfish ( Stegastes partitus) in the Mesoamerican Reef System (MRS), Western Caribbean, to investigate patterns of connectivity among populations over 2 years. First, we assessed spatial and temporal variability in trace elemental concentrations from the otolith edge to make a `chemical map' of potential source reef(s) in the region. Significant otolith chemical differences were detected at three spatial scales (within-atoll, between-atolls, and region-wide), such that individuals were classified to locations with moderate (52 % jackknife classification) to high (99 %) accuracy. Most sites at Turneffe Atoll, Belize showed significant temporal variability in otolith concentrations on the scale of 1-2 months. Using a maximum likelihood approach, we estimated the natal source of larvae recruiting to reefs across the MRS by comparing `natal' chemical signatures from the otolith of recruits to the `chemical map' of potential source reef(s). Our results indicated that populations at both Turneffe Atoll and Banco Chinchorro supply a substantial amount of individuals to their own reefs (i.e., self-recruitment) and thus emphasize that marine conservation and management in the MRS region would benefit from localized management efforts as well as international cooperation.

  4. Tuning stochastic matrix models with hydrologic data to predict the population dynamics of a riverine fish

    USGS Publications Warehouse

    Sakaris, P.C.; Irwin, E.R.

    2010-01-01

    We developed stochastic matrix models to evaluate the effects of hydrologic alteration and variable mortality on the population dynamics of a lotie fish in a regulated river system. Models were applied to a representative lotic fish species, the flathead catfish (Pylodictis olivaris), for which two populations were examined: a native population from a regulated reach of the Coosa River (Alabama, USA) and an introduced population from an unregulated section of the Ocmulgee River (Georgia, USA). Size-classified matrix models were constructed for both populations, and residuals from catch-curve regressions were used as indices of year class strength (i.e., recruitment). A multiple regression model indicated that recruitment of flathead catfish in the Coosa River was positively related to the frequency of spring pulses between 283 and 566 m3/s. For the Ocmulgee River population, multiple regression models indicated that year class strength was negatively related to mean March discharge and positively related to June low flow. When the Coosa population was modeled to experience five consecutive years of favorable hydrologic conditions during a 50-year projection period, it exhibited a substantial spike in size and increased at an overall 0.2% annual rate. When modeled to experience five years of unfavorable hydrologic conditions, the Coosa population initially exhibited a decrease in size but later stabilized and increased at a 0.4% annual rate following the decline. When the Ocmulgee River population was modeled to experience five years of favorable conditions, it exhibited a substantial spike in size and increased at an overall 0.4% annual rate. After the Ocmulgee population experienced five years of unfavorable conditions, a sharp decline in population size was predicted. However, the population quickly recovered, with population size increasing at a 0.3% annual rate following the decline. In general, stochastic population growth in the Ocmulgee River was more

  5. Impacts of invasive fish removal through angling on population characteristics and juvenile growth rate

    PubMed Central

    Evangelista, Charlotte; Britton, Robert J; Cucherousset, Julien

    2015-01-01

    Exploitation can modify the characteristics of fish populations through the selective harvesting of individuals, with this potentially leading to rapid ecological and evolutionary changes. Despite the well-known effects of invasive fishes on aquatic ecosystems generally, the potential effects of their selective removal through angling, a strategy commonly used to manage invasive fish, are poorly understood. The aim of this field-based study was to use the North American pumpkinseed Lepomis gibbosus as the model species to investigate the consequences of selective removal on their population characteristics and juvenile growth rates across 10 populations in artificial lakes in southern France. We found that the maximal individual mass in populations decreased as removal pressure through angling increased, whereas we did not observed any changes in the maximal individual length in populations as removal pressure increased. Total population abundance did not decrease as removal pressure increased; instead, here was a U-shaped relationship between removal pressure and the abundance of medium-bodied individuals. In addition, population biomass had a U-shaped curve response to removal pressure, implying that invasive fish populations can modulate their characteristics to compensate for the negative effects of selective removals. In addition, individual lengths at age 2 and juvenile growth rates decreased as removal pressure through angling increased, suggesting a shift toward an earlier size at maturity and an overall slower growing phenotype. Therefore, these outputs challenge the efficiency of selective management methods, suggesting the use of more proactive strategies to control invasive populations, and the need to investigate the potential ecological and evolutionary repercussions of nonrandom removal. PMID:26078856

  6. Flow management and fish density regulate salmonid recruitment and adult size in tailwaters across western North America.

    PubMed

    Dibble, Kimberly L; Yackulic, Charles B; Kennedy, Theodore A; Budy, Phaedra

    2015-12-01

    Rainbow and brown trout have been intentionally introduced into tailwaters downriver of dams globally and provide billions of dollars in economic benefits. At the same time, recruitment and maximum length of trout populations in tailwaters often fluctuate erratically, which negatively affects the value of fisheries. Large recruitment events may increase dispersal downriver where other fish species may be a priority (e.g., endangered species). There is an urgent need to understand the drivers of trout population dynamics in tailwaters, in particular the role of flow management. Here, we evaluate how flow, fish density, and other physical factors of the river influence recruitment and mean adult length in tailwaters across western North America, using data from 29 dams spanning 1-19 years. Rainbow trout recruitment was negatively correlated with high annual, summer, and spring flow and dam latitude, and positively correlated with high winter flow, subadult brown trout catch, and reservoir storage capacity. Brown trout recruitment was negatively correlated with high water velocity and daily fluctuations in flow (i.e., hydropeaking) and positively correlated with adult rainbow trout catch. Among these many drivers, rainbow trout recruitment was primarily correlated with high winter flow combined with low spring flow, whereas brown trout recruitment was most related to high water velocity. The mean lengths of adult rainbow and brown trout were influenced by similar flow and catch metrics. Length in both species was positively correlated with high annual flow but declined in tailwaters with high daily fluctuations in flow, high catch rates of conspecifics, and when large cohorts recruited to adult size. Whereas brown trout did not respond to the proportion of water allocated between seasons, rainbow trout length increased in rivers that released more water during winter than in spring. Rainbow trout length was primarily related to high catch rates of conspecifics

  7. A novel population health approach: Using fish retinoblastoma gene profiles as a surrogate for humans.

    PubMed

    Rotchell, Jeanette M; du Corbier, Frances A; Stentiford, Grant D; Lyons, Brett P; Liddle, Andrew R; Ostrander, Gary K

    2009-03-01

    Retinoblastoma, a tumor suppressor gene, is frequently mutated in diverse types of human tumors. We have previously shown that two types of fish tumor, eye and liver, also possess mutant Rb genes. Our aim is to determine if the Rb allele status is linked to environmentally-induced cancer and whether this information in fish can be used to predict future phenotype. This is a proof-of-concept investigation to elucidate if fish may act as surrogates in assessing pollution-induced tumor incidence and inform regulatory authorities of potential long-term population health consequences. Marine flatfish, Limanda limanda, that display either normal liver histopathology, liver adenoma or liver hepatocellular carcinoma were analysed for the presence of Rb gene alterations. Several Rb alterations were detected in the fish displaying adenoma and carcinoma, and not in the surrounding normal tissue from the same individuals. The profile is similar to that reported in humans in that they spread across the gene, particularly exons 8-23, and a functionally important region of the protein. This Rb allele data was then used to build statistical classifier sets, linking Rb status with tumor pathology. Further flatfish caught from coastal-water areas of differing contaminant burden around the UK were subsequently analysed for the presence of Rb alterations. Using novel pattern matching statistics of the classifier sets compared with the coastal samples, the coastal fish were considered more similar to the characterised disease phenotype than the normal phenotype. Preliminary data suggests that using a statistical approach, based on classifying sets of histopathologically-defined tumor states, makes it possible to predict the phenotype of wild fish based on the status of the Rb allele. Since the Rb gene is orthologous, fish populations could act as surrogates for human populations in an eco-epidemiological investigation of the combined roles of genetics and environmental exposures in the

  8. Educating and Training out of Poverty? Adult Provision and the Informal Sector in Fishing Communities, South Africa

    ERIC Educational Resources Information Center

    Petersen, Carolyn

    2007-01-01

    This paper looks at access to adult education and vocational education and training (VET) provision in fishing communities in the Western Cape, South Africa. Fishing communities are being disadvantaged due to geographical and socio-political marginalisation, and the predominance of informal sector employment in the context of worldwide marine…

  9. Serum concentrations of perfluorinated compounds (PFC) among selected populations of children and Adults in California

    PubMed Central

    Wu, Xiangmei (May); Bennett, Deborah H.; Calafat, Antonia M.; Kato, Kayoko; Strynar, Mark; Andersen, Erik; Moran, Rebecca E.; Tancredi, Daniel J.; Tulve, Nicolle S.; Hertz-Picciotto, Irva

    2016-01-01

    Perfluorinated compounds (PFCs) have been widely used in industrial applications and consumer products. Their persistent nature and potential health impacts are of concern. Given the high cost of collecting serum samples, this study is to understand whether we can quantify PFC serum concentrations using factors extracted from questionnaire responses and indirect measurements, and whether a single serum measurement can be used to classify an individual’s exposure over a one-year period. The study population included three demographic groups: young children (2–8 years old) (N=67), parents of young children (<55 years old) (N=90), and older adults (>55 years old) (N=59). PFC serum concentrations, house dust concentrations, and questionnaires were collected. The geometric mean of perfluorooctane sulfonic acid (PFOS) was highest for the older adults. In contrast, the geometric mean of perfluorooctanoic acid (PFOA) was highest for children. Serum concentrations of the parent and the child from the same family were moderately correlated (Spearman correlation (r)=0.26–0.79, p<0.05), indicating common sources within a family. For adults, age, having occupational exposure or having used fire extinguisher, frequencies of consuming butter/margarine, pork, canned meat entrées, tuna and white fish, freshwater fish, and whether they ate microwave popcorn were significantly positively associated with serum concentrations of individual PFCs. For children, residential dust concentrations, frequency of wearing waterproof clothes, frequency of having canned fish, hotdogs, chicken nuggets, French fries, and chips, and whether they ate microwave popcorn were significant positive predictors of individual PFC serum concentrations. In addition, the serum concentrations collected in a subset of young children (N=20) and the parents (N=42) one year later were strongly correlated (r=0.68–0.98, p<0.001) with the levels measured at the first visits, but showed a decreasing trend

  10. Serum concentrations of perfluorinated compounds (PFC) among selected populations of children and adults in California.

    PubMed

    Wu, Xiangmei May; Bennett, Deborah H; Calafat, Antonia M; Kato, Kayoko; Strynar, Mark; Andersen, Erik; Moran, Rebecca E; Tancredi, Daniel J; Tulve, Nicolle S; Hertz-Picciotto, Irva

    2015-01-01

    Perfluorinated compounds (PFCs) have been widely used in industrial applications and consumer products. Their persistent nature and potential health impacts are of concern. Given the high cost of collecting serum samples, this study is to understand whether we can quantify PFC serum concentrations using factors extracted from questionnaire responses and indirect measurements, and whether a single serum measurement can be used to classify an individual's exposure over a one-year period. The study population included three demographic groups: young children (2-8 years old) (N=67), parents of young children (<55 years old) (N=90), and older adults (>55 years old) (N=59). PFC serum concentrations, house dust concentrations, and questionnaires were collected. The geometric mean of perfluorooctane sulfonic acid (PFOS) was highest for the older adults. In contrast, the geometric mean of perfluorooctanoic acid (PFOA) was highest for children. Serum concentrations of the parent and the child from the same family were moderately correlated (Spearman correlation (r)=0.26-0.79, p<0.05), indicating common sources within a family. For adults, age, having occupational exposure or having used fire extinguisher, frequencies of consuming butter/margarine, pork, canned meat entrées, tuna and white fish, freshwater fish, and whether they ate microwave popcorn were significantly positively associated with serum concentrations of individual PFCs. For children, residential dust concentrations, frequency of wearing waterproof clothes, frequency of having canned fish, hotdogs, chicken nuggets, French fries, and chips, and whether they ate microwave popcorn were significant positive predictors of individual PFC serum concentrations. In addition, the serum concentrations collected in a subset of young children (N=20) and the parents (N=42) one year later were strongly correlated (r=0.68-0.98, p<0.001) with the levels measured at the first visits, but showed a decreasing trend. Children had

  11. LINKING HISTORICAL ORGANOCHLORINE EXPOSURES IN THE GREAT LAKES CAUSALLY TO MAJOR FISH POPULATION CHANGES

    EPA Science Inventory

    The Great Lakes of North America are large aquatic ecosystems that have been greatly impacted by human activities in the 20th century. Introduction of non-native species, both advertently and inadvertently; reduction in populations through commercial fishing; habitat alternation...

  12. VARIATION IN RESPONSIVENESS TO CONTAMINANTS IN WILD POPULATIONS OF ESTUARINE FISH, FUNDULUS HETERCLITUS

    EPA Science Inventory

    Populations of the non-migratory estuarine fish species Fundulus heteroclitus indigenous to a PCB-contaminated Superfund site (New Bedford Harbor, MA, USA) are markedly less sensitive to the toxic effects of local contaminants than those from a reference site. We characterized th...

  13. Contrasting environmental drivers of adult and juvenile growth in a marine fish: implications for the effects of climate change.

    PubMed

    Ong, Joyce Jia Lin; Rountrey, Adam Nicholas; Meeuwig, Jessica Jane; Newman, Stephen John; Zinke, Jens; Meekan, Mark Gregory

    2015-06-08

    Many marine fishes have life history strategies that involve ontogenetic changes in the use of coastal habitats. Such ontogenetic shifts may place these species at particular risk from climate change, because the successive environments they inhabit can differ in the type, frequency and severity of changes related to global warming. We used a dendrochronology approach to examine the physical and biological drivers of growth of adult and juvenile mangrove jack (Lutjanus argentimaculatus) from tropical north-western Australia. Juveniles of this species inhabit estuarine environments and adults reside on coastal reefs. The Niño-4 index, a measure of the status of the El Niño-Southern Oscillation (ENSO) had the highest correlation with adult growth chronologies, with La Niña years (characterised by warmer temperatures and lower salinities) having positive impacts on growth. Atmospheric and oceanographic phenomena operating at ocean-basin scales seem to be important correlates of the processes driving growth in local coastal habitats. Conversely, terrestrial factors influencing precipitation and river runoff were positively correlated with the growth of juveniles in estuaries. Our results show that the impacts of climate change on these two life history stages are likely to be different, with implications for resilience and management of populations.

  14. Contrasting environmental drivers of adult and juvenile growth in a marine fish: implications for the effects of climate change

    PubMed Central

    Ong, Joyce Jia Lin; Nicholas Rountrey, Adam; Jane Meeuwig, Jessica; John Newman, Stephen; Zinke, Jens; Gregory Meekan, Mark

    2015-01-01

    Many marine fishes have life history strategies that involve ontogenetic changes in the use of coastal habitats. Such ontogenetic shifts may place these species at particular risk from climate change, because the successive environments they inhabit can differ in the type, frequency and severity of changes related to global warming. We used a dendrochronology approach to examine the physical and biological drivers of growth of adult and juvenile mangrove jack (Lutjanus argentimaculatus) from tropical north-western Australia. Juveniles of this species inhabit estuarine environments and adults reside on coastal reefs. The Niño-4 index, a measure of the status of the El Niño-Southern Oscillation (ENSO) had the highest correlation with adult growth chronologies, with La Niña years (characterised by warmer temperatures and lower salinities) having positive impacts on growth. Atmospheric and oceanographic phenomena operating at ocean-basin scales seem to be important correlates of the processes driving growth in local coastal habitats. Conversely, terrestrial factors influencing precipitation and river runoff were positively correlated with the growth of juveniles in estuaries. Our results show that the impacts of climate change on these two life history stages are likely to be different, with implications for resilience and management of populations. PMID:26052896

  15. Contrasting environmental drivers of adult and juvenile growth in a marine fish: implications for the effects of climate change.

    PubMed

    Ong, Joyce Jia Lin; Rountrey, Adam Nicholas; Meeuwig, Jessica Jane; Newman, Stephen John; Zinke, Jens; Meekan, Mark Gregory

    2015-01-01

    Many marine fishes have life history strategies that involve ontogenetic changes in the use of coastal habitats. Such ontogenetic shifts may place these species at particular risk from climate change, because the successive environments they inhabit can differ in the type, frequency and severity of changes related to global warming. We used a dendrochronology approach to examine the physical and biological drivers of growth of adult and juvenile mangrove jack (Lutjanus argentimaculatus) from tropical north-western Australia. Juveniles of this species inhabit estuarine environments and adults reside on coastal reefs. The Niño-4 index, a measure of the status of the El Niño-Southern Oscillation (ENSO) had the highest correlation with adult growth chronologies, with La Niña years (characterised by warmer temperatures and lower salinities) having positive impacts on growth. Atmospheric and oceanographic phenomena operating at ocean-basin scales seem to be important correlates of the processes driving growth in local coastal habitats. Conversely, terrestrial factors influencing precipitation and river runoff were positively correlated with the growth of juveniles in estuaries. Our results show that the impacts of climate change on these two life history stages are likely to be different, with implications for resilience and management of populations. PMID:26052896

  16. [Alimentation dependent health disorders among adult population of Bashkortostan Republic and their relation with nutritional traits].

    PubMed

    Takaev, R M; Kondrova, N S; Baĭkina, I M; Larionova, T K

    2008-01-01

    The authors demonstrated relationship between alimentation dependent diseases among adult population of the Republic and nutritional traits of the population, defined major directions of program to optimize nutrition of the population.

  17. Predictors of Septic Arthritis in the Adult Population.

    PubMed

    Borzio, Robert; Mulchandani, Neil; Pivec, Robert; Kapadia, Bhaveen H; Leven, Dante; Harwin, Steven F; Urban, William P

    2016-07-01

    Septic arthritis is a devastating condition; well-established criteria for diagnosis exist in the pediatric population, but not for adults. This study evaluated patient factors and laboratory parameters that may be associated with the diagnosis of septic arthritis in adults. A total of 458 knee aspirates for suspected septic arthritis were evaluated with serum and synovial leukocyte counts and differentials as well as Kocher criteria for pediatric septic arthritis. Twenty-two patients (4.8%) had septic arthritis confirmed by a positive synovial fluid culture. Erythrocyte sedimentation rate (ESR) and serum white blood cell (WBC) counts were not statistically different between the 2 groups, with 64% of septic arthritis patients having a normal serum WBC count and 77% being afebrile. Mean synovial fluid WBC count was 26,758 cells/µL and 70,581 cells/µL in the nonseptic and septic groups, respectively. The likelihood ratio for a synovial fluid WBC count greater than 65,000 cells/µL was 2.8 (95% confidence interval, 1.2-6.7). Evaluation receiver operating characteristic curves using synovial WBC counts resulted in a significant area under the curve of 0.66 (P=.02). To achieve 90% specificity, a WBC cutoff of 64,000 cells/µL was required with a corresponding sensitivity of 40%. There was no significant difference in the synovial cell differential of 80% vs 90% in diagnosing infection. Synovial fluid WBC count greater than 64,000 cells/µL yielded the optimal combination of sensitivity and specificity. Polymorphonuclear leukocytes, ESR, serum WBC count, fever, and weight-bearing status were not significant predictors of septic arthritis. This study demonstrates the limited utility of Kocher criteria in the adult population and the importance of synovial leukocyte counts. [Orthopedics. 2016; 39(4):e657-e663.]. PMID:27286047

  18. Predictors of Septic Arthritis in the Adult Population.

    PubMed

    Borzio, Robert; Mulchandani, Neil; Pivec, Robert; Kapadia, Bhaveen H; Leven, Dante; Harwin, Steven F; Urban, William P

    2016-07-01

    Septic arthritis is a devastating condition; well-established criteria for diagnosis exist in the pediatric population, but not for adults. This study evaluated patient factors and laboratory parameters that may be associated with the diagnosis of septic arthritis in adults. A total of 458 knee aspirates for suspected septic arthritis were evaluated with serum and synovial leukocyte counts and differentials as well as Kocher criteria for pediatric septic arthritis. Twenty-two patients (4.8%) had septic arthritis confirmed by a positive synovial fluid culture. Erythrocyte sedimentation rate (ESR) and serum white blood cell (WBC) counts were not statistically different between the 2 groups, with 64% of septic arthritis patients having a normal serum WBC count and 77% being afebrile. Mean synovial fluid WBC count was 26,758 cells/µL and 70,581 cells/µL in the nonseptic and septic groups, respectively. The likelihood ratio for a synovial fluid WBC count greater than 65,000 cells/µL was 2.8 (95% confidence interval, 1.2-6.7). Evaluation receiver operating characteristic curves using synovial WBC counts resulted in a significant area under the curve of 0.66 (P=.02). To achieve 90% specificity, a WBC cutoff of 64,000 cells/µL was required with a corresponding sensitivity of 40%. There was no significant difference in the synovial cell differential of 80% vs 90% in diagnosing infection. Synovial fluid WBC count greater than 64,000 cells/µL yielded the optimal combination of sensitivity and specificity. Polymorphonuclear leukocytes, ESR, serum WBC count, fever, and weight-bearing status were not significant predictors of septic arthritis. This study demonstrates the limited utility of Kocher criteria in the adult population and the importance of synovial leukocyte counts. [Orthopedics. 2016; 39(4):e657-e663.].

  19. Morphological plasticity and phylogeny in a monogenean parasite transferring between wild and reared fish populations.

    PubMed

    Mladineo, Ivona; Šegvić-Bubić, Tanja; Stanić, Rino; Desdevises, Yves

    2013-01-01

    It is widely accepted that disease interactions between cultured and wild fish occur repeatedly, although reported cases have mainly relied just on the observation of similar symptoms in affected populations. Whether there is an explicit pathogen transfer between fish stocks, or each develops its own pathogen population, has been insufficiently studied and rarely supported by molecular tools. In this study, we used population dynamics and genetic structure of the monogenean Furnestinia echeneis in reared and neighbouring wild sea bream to indicate pathogen transfer, characterized by the phenotypic plasticity of the parasite attachment apparatus and the lack of phylogenetic differentiation. The observed pattern of genetic variation inferred by nuclear DNA Internal Transcribed Spacer 1 (ITS1) and mtDNA cytochrome C oxidase 1 (COI), between parasite populations is most likely caused by a recent shared demographic history like a reduced species area in the last glacial period. In spite of such recent expansion that populations underwent, F. echeneis shows differentiation in haptor morphometry as an adaptive trait in closely related populations at the aquaculture site. This suggests that differentiation in morphology may occur relatively rapidly in this species and that adaptive forces, not the speciation process, drives this monogenean parasitation. On the other hand, the observed phylogenetic inertia suggests a low to moderate gene flow (based on F ST ) between parasites in cultured and wild fish, evidencing for the first time the transfer of pathogens at the aquaculture site inferred by a molecular tool.

  20. Stabilization of population fluctuations due to cannibalism promotes resource polymorphism in fish.

    PubMed

    Andersson, Jens; Bystrom, Par; Claessen, David; Persson, Lennart; De Roos, Andre M

    2007-06-01

    Resource polymorphism is a well-known phenomenon in many taxa, assumed to be a consequence of strong competition for resources and to be facilitated by stable environments and the presence of several profitable resources on which to specialize. In fish, resource polymorphism, in the form of planktivore-benthivore pairs, is found in a number of species. We gathered literature data on life-history characteristics and population dynamics for 15 fish species and investigated factors related to the presence of such resource polymorphism. This investigation indicated that early cannibalism and low overall population variability are typically associated with the presence of resource polymorphism. These findings match previously reported patterns of population dynamics for size-structured fish populations, whereby early cannibalism has been shown to decrease temporal variation in population dynamics and to equalize the profitability of the zooplankton and macroinvertebrate resources. Our study suggests that competition alone is not a sufficient condition for the development of resource polymorphism because overly strong competition is typically associated with increased temporal variation (environmental instability). We conclude that although resource competition is an important factor regulating the development of resource polymorphism, cannibalism may also play a fundamental role by dampening population oscillations and possibly by equalizing the profitability of different resources. PMID:17479467

  1. Morphological Plasticity and Phylogeny in a Monogenean Parasite Transferring between Wild and Reared Fish Populations

    PubMed Central

    Mladineo, Ivona; Šegvić-Bubić, Tanja; Stanić, Rino; Desdevises, Yves

    2013-01-01

    It is widely accepted that disease interactions between cultured and wild fish occur repeatedly, although reported cases have mainly relied just on the observation of similar symptoms in affected populations. Whether there is an explicit pathogen transfer between fish stocks, or each develops its own pathogen population, has been insufficiently studied and rarely supported by molecular tools. In this study, we used population dynamics and genetic structure of the monogenean Furnestinia echeneis in reared and neighbouring wild sea bream to indicate pathogen transfer, characterized by the phenotypic plasticity of the parasite attachment apparatus and the lack of phylogenetic differentiation. The observed pattern of genetic variation inferred by nuclear DNA Internal Transcribed Spacer 1 (ITS1) and mtDNA cytochrome C oxidase 1 (COI), between parasite populations is most likely caused by a recent shared demographic history like a reduced species area in the last glacial period. In spite of such recent expansion that populations underwent, F. echeneis shows differentiation in haptor morphometry as an adaptive trait in closely related populations at the aquaculture site. This suggests that differentiation in morphology may occur relatively rapidly in this species and that adaptive forces, not the speciation process, drives this monogenean parasitation. On the other hand, the observed phylogenetic inertia suggests a low to moderate gene flow (based on FST) between parasites in cultured and wild fish, evidencing for the first time the transfer of pathogens at the aquaculture site inferred by a molecular tool. PMID:23620799

  2. Population persistence of stream fish in response to environmental change: integrating data and models across space

    NASA Astrophysics Data System (ADS)

    Letcher, B. H.; Schueller, P.; Bassar, R.; Coombs, J.; Rosner, A.; Sakrejda, K.; Kanno, Y.; Whiteley, A.; Nislow, K. H.

    2013-12-01

    For stream fishes, environmental variation is a key driver of individual body growth/movement/survival and, by extension, population dynamics. Identifying how stream fish respond to environmental variation can help clarify mechanisms responsible for population dynamics and can help provide tools to forecast relative resilience of populations across space. Forecasting dynamics across space is challenging, however, because it can be difficult to conduct enough studies with enough intensity to fully characterize broad-scale population response to environmental change. We have adopted a multi-scale approach, using detailed individual-based studies and analyses (integral projection matrix) to determine sensitivities of population growth to environmental variation combined with broad spatial data and analyses (occupancy and abundance models) to estimate patterns of population response across space. Population growth of brook trout was most sensitive to stream flow in the spring and winter, most sensitive to stream temperature in the fall and sensitive to both flow and temperature in the summer. High flow in the spring and winter had negative effects on population growth while high temperature had a negative effect in the fall. Flow had no effect when it was cold, but a positive effect when it was warm in the summer. Combined with occupancy and abundance models, these data give insight into the spatial structure of resilient populations and can help guide prioritization of management actions.

  3. Observations of migrant exchange and mixing in a coral reef fish metapopulation link scales of marine population connectivity.

    PubMed

    Horne, John B; van Herwerden, Lynne; Abellana, Sheena; McIlwain, Jennifer L

    2013-01-01

    Much progress has been made toward understanding marine metapopulation dynamics, largely because of multilocus microsatellite surveys able to connect related individuals within the metapopulation. However, most studies are focused on small spatial scales, tens of kilometers, while demographic exchange at larger spatial scales remains poorly documented. Additionally, many small-scale demographic studies conflict with broad-scale phylogeographic patterns concerning levels of marine population connectivity, highlighting a need for data on more intermediate scales. Here, we investigated demographic recruitment processes of a commercially important coral reef fish, the bluespine unicornfish (Naso unicornis) using a suite of mitochondrial DNA (mtDNA) and microsatellite markers. Sampling for this study ranged across the southern Marianas Islands, a linear distance of 250 km and included 386 newly settled postlarval recruits. In contrast with other studies, we report that cohorts of recruits were genetically homogeneous in space and time, with no evidence of temporally stochastic sweepstakes reproduction. The genetic diversity of recruits was high and commensurate with that of the adult population. In addition, there is substantial evidence that 2 recruits, separated by 250 km, were full siblings. This is the largest direct observation of dispersal to date for a coral reef fish. All indications suggest that subpopulations of N. unicornis experience high levels of demographic migrant exchange and metapopulation mixing on a spatial scale of hundreds of kilometers, consistent with high levels of broad-scale genetic connectivity previously reported in this species.

  4. Differences in male coloration are predicted by divergent sexual selection between populations of a cichlid fish.

    PubMed

    Selz, O M; Thommen, R; Pierotti, M E R; Anaya-Rojas, J M; Seehausen, O

    2016-05-11

    Female mating preferences can influence both intraspecific sexual selection and interspecific reproductive isolation, and have therefore been proposed to play a central role in speciation. Here, we investigate experimentally in the African cichlid fish Pundamilia nyererei if differences in male coloration between three para-allopatric populations (i.e. island populations with gene flow) of P. nyererei are predicted by differences in sexual selection by female mate choice between populations. Second, we investigate if female mating preferences are based on the same components of male coloration and go in the same direction when females choose among males of their own population, their own and other conspecific populations and a closely related para-allopatric sister-species, P. igneopinnis Mate-choice experiments revealed that females of the three populations mated species-assortatively, that populations varied in their extent of population-assortative mating and that females chose among males of their own population based on different male colours. Females of different populations exerted directional intrapopulation sexual selection on different male colours, and these differences corresponded in two of the populations to the observed differences in male coloration between the populations. Our results suggest that differences in male coloration between populations of P. nyererei can be explained by divergent sexual selection and that population-assortative mating may directly result from intrapopulation sexual selection. PMID:27147097

  5. Spatiotemporal relationship between adult census size and genetic population size across a wide population size gradient.

    PubMed

    Bernos, Thaїs A; Fraser, Dylan J

    2016-09-01

    Adult census population size (N) and effective number of breeders (Nb ) are highly relevant for designing effective conservation strategies. Both parameters are often challenging to quantify, however, making it of interest to determine whether one parameter can be generalized from the other. Yet, the spatiotemporal relationship between N and Nb has not been well characterized empirically in many taxa. We analysed this relationship for 5-7 consecutive years in twelve brook trout populations varying greatly in N (49-10032) and Nb (3-567) and identified major environmental variables affecting the two parameters. N or habitat size alone explained 47-57% of the variance in Nb , and Nb was strongly correlated with effective population size. The ratio Nb /N ranged from 0.01 to 0.45 and increased at small N or following an annual decrease in N, suggesting density-dependent constraints on Nb . We found no evidence for a consistent, directional difference between variability in Nb and/or Nb /N among small and large populations; however, small populations had more varying temporal variability in Nb /N ratios than large populations. Finally, Nb and Nb /N were 2.5- and 2.3-fold more variable among populations than temporally within populations. Our results demonstrate a clear linkage between demographic and evolutionary parameters, suggesting that Nb could be used to approximate N (or vice versa) in natural populations. Nevertheless, using one variable to infer the other to monitor trends within populations is less recommended, perhaps even less so in small populations given their less predictable Nb vs. N dynamics. PMID:27483203

  6. Determination of a site-specific reference dose for methylmercury for fish-eating populations.

    PubMed

    Shipp, A M; Gentry, P R; Lawrence, G; Van Landingham, C; Covington, T; Clewell, H J; Gribben, K; Crump, K

    2000-11-01

    methylmercury, the exposures of concern for the Point Comfort site are from the chronic consumption of relatively low concentrations of methylmercury in fish. Since the publication of the USEPA RfD, several analyses of chronic exposure to methylmercury in fish-eating populations have been reported. The purpose of the analysis reported here was to evaluate the possibility of deriving an RfD for methylmercury, specifically for the case of fish ingestion, on the basis of these new studies. In order to better support the risk-management decisions associated with developing a remediation approach for the site in question, the analysis was designed to provide information on the distribution of acceptable ingestion rates across a population, which could reasonably be expected to be consistent with the results of the epidemiological studies of other fish-eating populations. Based on a review of the available literature on the effects of methylmercury, a study conducted with a population in the Seychelles Islands was selected as the critical study for this analysis. The exposures to methylmercury in this population result from chronic, multigenerational ingestion of contaminated fish. This prospective study was carefully conducted and analyzed, included a large cohort of mother-infant pairs, and was relatively free of confounding factors. The results of this study are essentially negative, and a no-observed-adverse-effect level (NOAEL) derived from the estimated exposures has recently been used by the Agency for Toxic Substances and Disease Registry (ATSDR) as the basis for a chronic oral minimal risk level (MRL) for methylmercury. In spite of the fact that no statistically significant effects were observed in this study, the data as reported are suitable for dose-response analysis using the BMD method. Evaluation of the BMD method used in this analysis, as well as in the current USEPA RfD, has demonstrated that the resulting 95% lower bound on the 10% benchmark dose (BMDL) represents a

  7. Determination of a site-specific reference dose for methylmercury for fish-eating populations.

    PubMed

    Shipp, A M; Gentry, P R; Lawrence, G; Van Landingham, C; Covington, T; Clewell, H J; Gribben, K; Crump, K

    2000-11-01

    methylmercury, the exposures of concern for the Point Comfort site are from the chronic consumption of relatively low concentrations of methylmercury in fish. Since the publication of the USEPA RfD, several analyses of chronic exposure to methylmercury in fish-eating populations have been reported. The purpose of the analysis reported here was to evaluate the possibility of deriving an RfD for methylmercury, specifically for the case of fish ingestion, on the basis of these new studies. In order to better support the risk-management decisions associated with developing a remediation approach for the site in question, the analysis was designed to provide information on the distribution of acceptable ingestion rates across a population, which could reasonably be expected to be consistent with the results of the epidemiological studies of other fish-eating populations. Based on a review of the available literature on the effects of methylmercury, a study conducted with a population in the Seychelles Islands was selected as the critical study for this analysis. The exposures to methylmercury in this population result from chronic, multigenerational ingestion of contaminated fish. This prospective study was carefully conducted and analyzed, included a large cohort of mother-infant pairs, and was relatively free of confounding factors. The results of this study are essentially negative, and a no-observed-adverse-effect level (NOAEL) derived from the estimated exposures has recently been used by the Agency for Toxic Substances and Disease Registry (ATSDR) as the basis for a chronic oral minimal risk level (MRL) for methylmercury. In spite of the fact that no statistically significant effects were observed in this study, the data as reported are suitable for dose-response analysis using the BMD method. Evaluation of the BMD method used in this analysis, as well as in the current USEPA RfD, has demonstrated that the resulting 95% lower bound on the 10% benchmark dose (BMDL) represents a

  8. The prevalence of periodontal diseases among adult population in Georgia.

    PubMed

    Tsitaishvili, L; Margvelashvili, M; Kalandadze, M; Margvelashvili, V

    2014-09-01

    The present research was conducted to estimate the prevalence of periodontal diseases in the adult population of Georgia, to study the peculiarity of their distribution within population in different regions of the country. The survey was carried out based on cluster- stratified method derived by WHO. 2370 adults including 1289 women and 1081 men distributed in 4 age groups: I - 20-34, II - 35-44, III - 45-64, IV - 65+ the residents of the city, town and village in 9 regions of Georgia and the capital Tbilisi were examined. The assessment of periodontal status and oral hygiene was based on WHO-'s recommendation. (WHO 1997 '˜Oral Health Assessment Form') Examination was done under good natural light using a mouth mirror and a periodontal index (CPI) probe for measurements of periodontal pockets depth. Questionnaires comprised questions for revealing the following risk factors: social status and family income, existence of common diseases, people'S attitude towards oral hygiene(tooth brushing, using dental floss, mouth rinsing) acceptability of dental service, sugar consumption rate, tobacco use, consumption of dairy products. The reliable statistical data received from the study relieved high prevalence of periodontal diseases in all regions: in Achara - 71.7, Mtskheta-Mtianeti - 70.8%, Imereti - 64.9%, Qvemo Qartli - 61.6%, Tbilisi - 61.8% and Shida Qartli - 60.5%, Guria - 55.9%, Samtskhe-Javakheti - 56.0%, Kakheti - 59.1%, Samegrelo - 55.2%. Despite the variability of risk factors high prevalence of inflammatory periodontal diseases in regions of Georgia was related to more extent to the low educational medical background, less dental acceptability due to not very positive attitude towards dental service and oral hygiene skills though financial problems also played substantial role. The study confirmed that periodontal diseases represent an actual problem in Georgia and need caring out serious preventive measures to enhance peoples' referral to dental service and

  9. Young adults' trajectories of Ecstasy use: a population based study.

    PubMed

    Smirnov, Andrew; Najman, Jake M; Hayatbakhsh, Reza; Plotnikova, Maria; Wells, Helene; Legosz, Margot; Kemp, Robert

    2013-11-01

    Young adults' Ecstasy use trajectories have important implications for individual and population-level consequences of Ecstasy use, but little relevant research has been conducted. This study prospectively examines Ecstasy trajectories in a population-based sample. Data are from the Natural History Study of Drug Use, a retrospective/prospective cohort study conducted in Australia. Population screening identified a probability sample of Ecstasy users aged 19-23 years. Complete data for 30 months of follow-up, comprising 4 time intervals, were available for 297 participants (88.4% of sample). Trajectories were derived using cluster analysis based on recent Ecstasy use at each interval. Trajectory predictors were examined using a generalized ordered logit model and included Ecstasy dependence (World Mental Health Composite International Diagnostic Instrument), psychological distress (Hospital Anxiety Depression Scale), aggression (Young Adult Self Report) and contextual factors (e.g. attendance at electronic/dance music events). Three Ecstasy trajectories were identified (low, intermediate and high use). At its peak, the high-use trajectory involved 1-2 days Ecstasy use per week. Decreasing frequency of use was observed for intermediate and high-use trajectories from 12 months, independently of market factors. Intermediate and high-use trajectory membership was predicted by past Ecstasy consumption (>70 pills) and attendance at electronic/dance music events. High-use trajectory members were unlikely to have used Ecstasy for more than 3 years and tended to report consistently positive subjective effects at baseline. Given the social context and temporal course of Ecstasy use, Ecstasy trajectories might be better understood in terms of instrumental rather than addictive drug use patterns.

  10. The prevalence of periodontal diseases among adult population in Georgia.

    PubMed

    Tsitaishvili, L; Margvelashvili, M; Kalandadze, M; Margvelashvili, V

    2014-09-01

    The present research was conducted to estimate the prevalence of periodontal diseases in the adult population of Georgia, to study the peculiarity of their distribution within population in different regions of the country. The survey was carried out based on cluster- stratified method derived by WHO. 2370 adults including 1289 women and 1081 men distributed in 4 age groups: I - 20-34, II - 35-44, III - 45-64, IV - 65+ the residents of the city, town and village in 9 regions of Georgia and the capital Tbilisi were examined. The assessment of periodontal status and oral hygiene was based on WHO-'s recommendation. (WHO 1997 '˜Oral Health Assessment Form') Examination was done under good natural light using a mouth mirror and a periodontal index (CPI) probe for measurements of periodontal pockets depth. Questionnaires comprised questions for revealing the following risk factors: social status and family income, existence of common diseases, people'S attitude towards oral hygiene(tooth brushing, using dental floss, mouth rinsing) acceptability of dental service, sugar consumption rate, tobacco use, consumption of dairy products. The reliable statistical data received from the study relieved high prevalence of periodontal diseases in all regions: in Achara - 71.7, Mtskheta-Mtianeti - 70.8%, Imereti - 64.9%, Qvemo Qartli - 61.6%, Tbilisi - 61.8% and Shida Qartli - 60.5%, Guria - 55.9%, Samtskhe-Javakheti - 56.0%, Kakheti - 59.1%, Samegrelo - 55.2%. Despite the variability of risk factors high prevalence of inflammatory periodontal diseases in regions of Georgia was related to more extent to the low educational medical background, less dental acceptability due to not very positive attitude towards dental service and oral hygiene skills though financial problems also played substantial role. The study confirmed that periodontal diseases represent an actual problem in Georgia and need caring out serious preventive measures to enhance peoples' referral to dental service and

  11. Young adults' trajectories of Ecstasy use: a population based study.

    PubMed

    Smirnov, Andrew; Najman, Jake M; Hayatbakhsh, Reza; Plotnikova, Maria; Wells, Helene; Legosz, Margot; Kemp, Robert

    2013-11-01

    Young adults' Ecstasy use trajectories have important implications for individual and population-level consequences of Ecstasy use, but little relevant research has been conducted. This study prospectively examines Ecstasy trajectories in a population-based sample. Data are from the Natural History Study of Drug Use, a retrospective/prospective cohort study conducted in Australia. Population screening identified a probability sample of Ecstasy users aged 19-23 years. Complete data for 30 months of follow-up, comprising 4 time intervals, were available for 297 participants (88.4% of sample). Trajectories were derived using cluster analysis based on recent Ecstasy use at each interval. Trajectory predictors were examined using a generalized ordered logit model and included Ecstasy dependence (World Mental Health Composite International Diagnostic Instrument), psychological distress (Hospital Anxiety Depression Scale), aggression (Young Adult Self Report) and contextual factors (e.g. attendance at electronic/dance music events). Three Ecstasy trajectories were identified (low, intermediate and high use). At its peak, the high-use trajectory involved 1-2 days Ecstasy use per week. Decreasing frequency of use was observed for intermediate and high-use trajectories from 12 months, independently of market factors. Intermediate and high-use trajectory membership was predicted by past Ecstasy consumption (>70 pills) and attendance at electronic/dance music events. High-use trajectory members were unlikely to have used Ecstasy for more than 3 years and tended to report consistently positive subjective effects at baseline. Given the social context and temporal course of Ecstasy use, Ecstasy trajectories might be better understood in terms of instrumental rather than addictive drug use patterns. PMID:23899430

  12. COST AND BENEFITS OF ALTERED BENZO(A)PYRENE METABOLISM IN A PCB-ADAPTED FISH POPULATION

    EPA Science Inventory

    We examined populations of an estuarine fish species (Fundulus heteroclitus) resident to a highly contaminated site and a reference site for their ability to metabolize an important environmental pollutant. In previous work, we characterized the fish population resident to this h...

  13. Trophic status and helminth infracommunities of fish populations in Kashmir Himalayan lakes.

    PubMed

    Shah, H B; Yousuf, A R; Chishti, M Z; Shahnaz, S; Ahmad, F

    2014-09-01

    The present study considers the influence of the trophic status of three Kashmir Himalayan lakes on the patterns of helminth infracommunities in populations of three species of fish during 2006 to 2008. Data were collected from three lakes of differing trophic status in the Kashmir Himalayas, namely Anchar, a hyper(eu)trophic lake; Dal, a eutrophic lake; and Manasbal, a meso(eu)trophic lake. Three species of fish examined included the native fish Schizothorax niger Heckel and two exotic species--Carassius carassius (Linnaeus) and Cyprinus carpio Linnaeus. The analysis of data showed a clear habitat effect on the abundance pattern of helminth species, thus revealing lake-specific differences in parasite infracommunities of both S. niger and C. carassius. Helminth infracommunity richness was the highest in host populations from the Anchar lake compared to other two lakes. Low values in the Manasbal lake emphasize the low diversity of their helminth infracommunities. On the other hand, there was no observed pattern of community structure in the case of C. carpio in the three lake sites. However due to bias in sampling there was no distinct effect of fish body size on parasite infracommunity structure, although the present results do show that fish parasite data can be meaningful in diagnosing changes in the trophic condition of eutrophic lakes.

  14. Marine protected areas facilitate parasite populations among four fished host species of central Chile.

    PubMed

    Wood, Chelsea L; Micheli, Fiorenza; Fernández, Miriam; Gelcich, Stefan; Castilla, Juan Carlos; Carvajal, Juan

    2013-11-01

    1. Parasites comprise a substantial proportion of global biodiversity and exert important ecological influences on hosts, communities and ecosystems, but our knowledge of how parasite populations respond to human impacts is in its infancy. 2. Here, we present the results of a natural experiment in which we used a system of highly successful marine protected areas and matched open-access areas in central Chile to assess the influence of fishing-driven biodiversity loss on parasites of exploited fish and invertebrate hosts. We measured the burden of gill parasites for two reef fishes (Cheilodactylus variegatus and Aplodactylus punctatus), trematode parasites for a keyhole limpet (Fissurella latimarginata), and pinnotherid pea crab parasites for a sea urchin (Loxechinus albus). We also measured host density for all four hosts. 3. We found that nearly all parasite species exhibited substantially greater density (# parasites m(-2)) in protected than in open-access areas, but only one parasite species (a gill monogenean of C. variegatus) was more abundant within hosts collected from protected relative to open-access areas. 4. These data indicate that fishing can drive declines in parasite abundance at the parasite population level by reducing the availability of habitat and resources for parasites, but less commonly affects the abundance of parasites at the infrapopulation level (within individual hosts). 5. Considering the substantial ecological role that many parasites play in marine communities, fishing and other human impacts could exert cryptic but important effects on marine community structure and ecosystem functioning via reductions in parasite abundance.

  15. Geographic variations in tumor prevalence among marine fish populations.

    PubMed

    Stich, H F; Action, A B; Dunn, B P; Oishi, K; Yamazaki, F; Harada, T; Peters, G; Peters, N

    1977-11-15

    A global epidemiological study on the frequency of skin papillomas among various flatfish species (Pleuronectids), papillomas of eels and the virus induced lymphocystis disease has revealed particular distribution patterns. Skin papillomas are prevalent among at least 20 flatfish species of the northern Pacific Ocean, Bering Sea, Sea of Okhotsk, and Japan Sea but appear to be absent from the Atlantic, North Sea, and the Caribbean Sea. The opposite is found for lymphocystis, which is common among flatfish species of the Atlantic shores of Europe and North America. Similarly the skin papillomas of eels are restricted to relatively small region along the European coast extending from the Baltic countries to Denmark, Germany and Holland. Superimposed on this global distribution pattern are local variations in tumor prevalences which can vary from about 58% to 0.01%. The geographic distribution pattern points to the existence of areas around the globe in which flatfish or eels are able to develop skin papillomas. Outside these areas of "potential skin papilloma risk," flatfish and eel populations are not afflicted with papillomas even if they inhabit estuaries or rivers with a high man-made or naturally-occurring pollution. PMID:924694

  16. Primitive neuroectodermal tumor of the central nervous system with glial differentiation: a FISH study of an adult case.

    PubMed

    Alameda, F; Lloreta, J; Ariza, A; Salido, M; Espinet, B; Baro, T; Garcia-Fructoso, G; Galito, E; Munne, A; Cruz Sanchez, F F; Sole, F; Serrano, S

    2007-01-01

    Primitive neuroectodermal tumors (PNETs) of the central nervous system (CNS), a rare occurrence in adults, may show glial differentiation and can be misinterpreted as pure astrocytic neoplasms. Few fluorescence in situ hybridization (FISH) studies have been carried out on these tumors; isochromosome 17q was found to be the major chromosomal abnormality. We present the case of an adult in which we performed a FISH study of both the glial and neuronal components. A complex array of FISH changes, not including an isochromosome 17q were identified.

  17. Fish population studies using parasites from the Southeastern Pacific Ocean: considering host population changes and species body size as sources of variability of parasite communities.

    PubMed

    George-Nascimento, Mario; Oliva, Marcelo

    2015-01-01

    Research using parasites in fish population studies in the South Eastern Pacific (SEP) is summarized. There are 27 such studies (snapshots mainly) in single host species sampled at different geographic localities and at somewhat similar times. They have been devoted mainly to economically important species, though others on coastal and intertidal fish or on less- or non-commercial species provide insights on scales of temporal and spatial variation of parasite infracommunities. Later, we assess whether the probability of harbouring parasites depends on the host species body size. Our results indicate that a stronger tool for fish population studies may be developed under regular (long term) scrutiny of parasite communities, especially of small fish host species, due to their larger variability in richness, abundance and total biomass, than in large fish species. Finally, it might also be necessary to consider the effects of fishing on parasite communities as well as the natural oscillations (coupled or not) of host and parasite populations.

  18. Fish populations associated with habitat-modified piers and natural woody debris in Piedmont Carolina reservoirs

    USGS Publications Warehouse

    Barwick, R.D.; Kwak, T.J.; Noble, R.L.; Barwick, D.H.

    2004-01-01

    A primary concern associated with reservoir shoreline residential development is reduction of littoral habitat complexity and diversity. One potential approach to compensate for this is the deployment of artificial-habitat modules under existing piers, but the benefit of this practice has not been demonstrated. To evaluate the effect of pier habitat modifications on fish populations in two Piedmont Carolina reservoirs, we studied 77 piers located on forty-seven, 100-m transects that were modified using plastic "fish hab" modules augmented with brush (brushed habs), hab modules alone (habs), or left unaltered for reference purposes. We sampled fish from all piers and transects during April, July, and October 2001 using a boat-mounted electrofisher. With few exceptions, catch rates were higher at brushed-hab piers and piers with habs than at reference piers during all seasons. Similarly, during spring and summer, fish abundance was generally higher on transects containing natural woody debris, brushed habs, and habs than on reference-developed transects; however, during fall, there were exceptions. Therefore, fish abundance associated with shorelines in these reservoirs appears to be related to the structural complexity of available habitat rather than structure composition. One year after installation, 92% of pier owners responding to a mail survey expressed satisfaction with pier modifications. Supplementing piers with habitat structures is recommended to enhance littoral habitat complexity for fishes in residentially developed reservoirs.

  19. Age and Time Population Differences: Young Adults, Gen Xers, and Millennials

    ERIC Educational Resources Information Center

    Menard, Lauren A.

    2013-01-01

    Age and Time disparities in young adult research populations are common because young adults are defined by varying age spans; members of Generation X and Millennial generations may both be considered young adults; study years vary, affecting populations; and qualitative methods with limited age/year samples are frequently utilized. The current…

  20. Importance of the habitat choice behavior assumed when modeling the effects of food and temperature on fish populations

    USGS Publications Warehouse

    Wildhaber, M.L.; Lamberson, P.J.

    2004-01-01

    Various mechanisms of habitat choice in fishes based on food and/or temperature have been proposed: optimal foraging for food alone; behavioral thermoregulation for temperature alone; and behavioral energetics and discounted matching for food and temperature combined. Along with development of habitat choice mechanisms, there has been a major push to develop and apply to fish populations individual-based models that incorporate various forms of these mechanisms. However, it is not known how the wide variation in observed and hypothesized mechanisms of fish habitat choice could alter fish population predictions (e.g. growth, size distributions, etc.). We used spatially explicit, individual-based modeling to compare predicted fish populations using different submodels of patch choice behavior under various food and temperature distributions. We compared predicted growth, temperature experience, food consumption, and final spatial distribution using the different models. Our results demonstrated that the habitat choice mechanism assumed in fish population modeling simulations was critical to predictions of fish distribution and growth rates. Hence, resource managers who use modeling results to predict fish population trends should be very aware of and understand the underlying patch choice mechanisms used in their models to assure that those mechanisms correctly represent the fish populations being modeled.

  1. Trends in diet quality among adolescents, adults and older adults: A population-based study.

    PubMed

    Andrade, Samantha Caesar de; Previdelli, Ágatha Nogueira; Cesar, Chester Luiz Galvão; Marchioni, Dirce Maria Lobo; Fisberg, Regina Mara

    2016-12-01

    This study aimed to monitor diet quality and associated factors in adolescents, adults and older adults from the city of São Paulo, Brazil. We conducted a cross-sectional population-based study involving 2376 individuals surveyed in 2003, and 1662 individuals in 2008 (Health Survey of São Paulo, ISA-Capital). Participants were of both sexes and aged 12 to 19 years old (adolescents), 20 to 59 years old (adults) and 60 years old or over (older adults). Food intake was assessed using the 24-h dietary recall method while diet quality was determined by the Brazilian Healthy Eating Index (BHEI-R). The prevalence of descriptive variables for 2003 and 2008 was compared adopting a confidence interval of 95%. The means of total BHEI-R score and its components for 2003 and 2008 were compared for each age group. Associations between the BHEI-R and independent variables were evaluated for each survey year using multiple linear regression analysis. Results showed that the mean BHEI-R increased (54.9 vs. 56.4 points) over the five-year period. However, the age group evaluation showed a deterioration in diet quality of adolescents, influenced by a decrease in scores for dark-green and orange vegetables and legumes, total grains, oils and SoFAAS (solid fat, alcohol and added sugar) components. In the 2008 survey, adults had a higher BHEI-R score, by 6.1 points on average, compared to adolescents. Compared to older adults, this difference was 10.7 points. The diet quality remains a concern, especially among adolescents, that had the worst results compared to the other age groups. PMID:27547722

  2. Local retention, dispersal and fluctuating connectivity among populations of a coral reef fish.

    PubMed

    Hogan, J Derek; Thiessen, Roger J; Sale, Peter F; Heath, Daniel D

    2012-01-01

    The persistence and resilience of marine populations in the face of disturbances is directly affected by connectivity among populations. Thus, understanding the magnitude and pattern of connections among populations and the temporal variation in these patterns is critical for the effective management and conservation of marine species. Despite recent advances in our understanding of marine connectivity, few empirical studies have directly measured the magnitude or pattern of connections among populations of marine fishes, and none have explicitly investigated temporal variation in demographic connectivity. We use genetic assignment tests to track the dispersal of 456 individual larval fishes to quantify the extent of connectivity, dispersal, self-recruitment and local retention within and among seven populations of a coral reef fish (Stegastes partitus) over a three-year period. We found that some larvae do disperse long distances (~200 km); however, self-recruitment was a regular phenomenon. Importantly, we found that dispersal distances, self-recruitment, local retention and the pattern of connectivity varied significantly among years. Our data highlight the unpredictable nature of connectivity, and underscore the need for more, temporally replicated, empirical measures of connectivity to inform management decisions. PMID:21735201

  3. Population genomics of marine fishes: next-generation prospects and challenges.

    PubMed

    Hemmer-Hansen, Jakob; Therkildsen, Nina Overgaard; Pujolar, José Martin

    2014-10-01

    Over the past few years, technological advances have facilitated giant leaps forward in our ability to generate genome-wide molecular data, offering exciting opportunities for gaining new insights into the ecology and evolution of species where genomic information is still limited. Marine fishes are valuable organisms for advancing our understanding of evolution on historical and contemporary time scales, and here we highlight areas in which research on these species is likely to be particularly important in the near future. These include possibilities for gaining insights into processes on ecological time scales, identifying genomic signatures associated with population divergence under gene flow, and determining the genetic basis of phenotypic traits. We also consider future challenges pertaining to the implementation of genome-wide coverage through next-generation sequencing and genotyping methods in marine fishes. Complications associated with fast decay of linkage disequilibrium, as expected for species with large effective population sizes, and the possibility that adaptation is associated with both soft selective sweeps and polygenic selection, leaving complex genomic signatures in natural populations, are likely to challenge future studies. However, the combination of high genome coverage and new statistical developments offers promising solutions. Thus, the next generation of studies is likely to truly facilitate the transition from population genetics to population genomics in marine fishes. This transition will advance our understanding of basic evolutionary processes and will offer new possibilities for conservation and management of valuable marine resources.

  4. Overestimating Fish Counts by Non-Instantaneous Visual Censuses: Consequences for Population and Community Descriptions

    PubMed Central

    Ward-Paige, Christine; Mills Flemming, Joanna; Lotze, Heike K.

    2010-01-01

    Background Increasingly, underwater visual censuses (UVC) are used to assess fish populations. Several studies have demonstrated the effectiveness of protected areas for increasing fish abundance or provided insight into the natural abundance and structure of reef fish communities in remote areas. Recently, high apex predator densities (>100,000 individuals·km−2) and biomasses (>4 tonnes·ha−1) have been reported for some remote islands suggesting the occurrence of inverted trophic biomass pyramids. However, few studies have critically evaluated the methods used for sampling conspicuous and highly mobile fish such as sharks. Ideally, UVC are done instantaneously, however, researchers often count animals that enter the survey area after the survey has started, thus performing non-instantaneous UVC. Methodology/Principal Findings We developed a simulation model to evaluate counts obtained by divers deploying non-instantaneous belt-transect and stationary-point-count techniques. We assessed how fish speed and survey procedure (visibility, diver speed, survey time and dimensions) affect observed fish counts. Results indicate that the bias caused by fish speed alone is huge, while survey procedures had varying effects. Because the fastest fishes tend to be the largest, the bias would have significant implications on their biomass contribution. Therefore, caution is needed when describing abundance, biomass, and community structure based on non-instantaneous UVC, especially for highly mobile species such as sharks. Conclusions/Significance Based on our results, we urge that published literature state explicitly whether instantaneous counts were made and that survey procedures be accounted for when non-instantaneous counts are used. Using published density and biomass values of communities that include sharks we explore the effect of this bias and suggest that further investigation may be needed to determine pristine shark abundances and the existence of inverted

  5. Applying population genetics for authentication of marine fish: the case of saithe (Pollachius virens).

    PubMed

    Behrmann, Konstanze; Rehbein, Hartmut; von Appen, Annika; Fischer, Markus

    2015-01-28

    The number of fishery products with a quite detailed description of the origin is increasing. This trend is driven by the interest of consumers and the fight against illegal unregulated and unreported fisheries. Unfortunately, there is a lack of methods to prove this information experimentally besides the document-based traceability assessments. For marine fish population genetics is a promising strategy, but research is concentrated only on a few species. Saithe is a commercially important fish species, despite the fact that genetic knowledge is scarce regarding the specification of populations. For a comparative study cost- and time-effective strategies were tested: We found RAPD-PCR to be a useful method for low-budget research or prestudies. Adoption of microsatellites from closely related species turned out to be possible with limited success quota. Our results suggest a clustered structure of populations within the Northeast Atlantic, probably overlapping in the northern North Sea.

  6. Impact of climate change on fish population dynamics in the Baltic sea: a dynamical downscaling investigation.

    PubMed

    Mackenzie, Brian R; Meier, H E Markus; Lindegren, Martin; Neuenfeldt, Stefan; Eero, Margit; Blenckner, Thorsten; Tomczak, Maciej T; Niiranen, Susa

    2012-09-01

    Understanding how climate change, exploitation and eutrophication will affect populations and ecosystems of the Baltic Sea can be facilitated with models which realistically combine these forcings into common frameworks. Here, we evaluate sensitivity of fish recruitment and population dynamics to past and future environmental forcings provided by three ocean-biogeochemical models of the Baltic Sea. Modeled temperature explained nearly as much variability in reproductive success of sprat (Sprattus sprattus; Clupeidae) as measured temperatures during 1973-2005, and both the spawner biomass and the temperature have influenced recruitment for at least 50 years. The three Baltic Sea models estimate relatively similar developments (increases) in biomass and fishery yield during twenty-first century climate change (ca. 28 % range among models). However, this uncertainty is exceeded by the one associated with the fish population model, and by the source of global climate data used by regional models. Knowledge of processes and biases could reduce these uncertainties.

  7. Algal populations controlled by fish herbivory across a wave exposure gradient on southern temperate shores.

    PubMed

    Taylor, David I; Schiel, David R

    2010-01-01

    Consumers that forage across habitats can affect communities by altering the abundance and distribution of key species. In marine communities, studies of trophic interactions have generally focused on the effects of herbivorous and predatory invertebrates on benthic algae and mussel populations. However, large mobile consumers that move across habitats, such as fishes, can strongly affect community dynamics through consumption of habitat-dominating species, but their effects often vary over environmental gradients. On temperate rocky shores, herbivorous fishes are generally a small part of the fish fauna compared to the tropics, and there is sparse evidence that they play a major direct role in algal community dynamics, particularly of large brown algae that dominate many reefs. In New Zealand, however, a wide-ranging herbivorous fish, Odax pullus, feeds exclusively on macroalgae, including Durvillaea antarctica, a large low-intertidal fucoid reaching 10 m in length and 70 kg in mass. In four experiments we tested the extent of fish herbivory and how it was affected by algal canopy structure across a gradient of wave exposure at multiple sites. Exclusion experiments showed that fish impacts greatly reduced the cover and biomass of Durvillaea and that these effects decreased with increasing wave stress and algal canopy cover, effectively restricting the alga to exposed conditions. Almost all plants were entirely removed by fish where there was a sparse algal canopy in sheltered and semi-exposed sites, but there was significantly less grazing in exposed sites. Recruit Durvillaea beneath canopies were less affected by fish grazing, but they grew slowly. Successful natural recruitment, therefore, occurred almost exclusively on exposed shores outside canopies where many plants escaped severe grazing, and growth to maturity was far greater than elsewhere. Such large and direct impacts on the local and regional distribution of large brown algal populations by mobile

  8. Nematodes parasitic in fishes of cenotes (= sinkholes) of the Peninsula of Yucatan, Mexico. Part 1. Adults.

    PubMed

    Moravec, F; Vivas-Rodríguez, C; Scholz, T; Vargas-Vázquez, J; Mendoza-Franco, E; González-Solís, D

    1995-01-01

    The present paper comprises a systematic survey of adult nematodes collected from fishes from cenotes (= sinkholes) of the Peninsula of Yucatan, southeastern Mexico, in 1993-1994. Examinations of a total of 533 fishes (17 species) originating from 39 cenotes from the Mexican states of Yucatan and Quintana Roo revealed the presence of the following nine nematode species: Rhabdochona (Rhabdochona) kidderi, Procamallanus (Spirocamallanus) rebecae, P. (S.) neocaballeroi, Philometroides caudata, Hysterothylacium cenotue. Pseudocapillaria yucatanensis, Paracapillaria rhamdiae, P. teixerafreitasi and Capillostrongyloides sp. (only females). Four species (R. kidderi, P. rebecae, P. neocaballeroi and Capillostrongyloides sp.) are briefly described and illustrated and some problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. Taxonomic changes include Procamallanus (Spirocamallanus) neocaballeroi (Caballero-Deloya. 1977) comb. n. and Procamallanus (Spirocamallanus) rebecae (Andrade-Salas, Pineda-López et García-Magaña, 1994) comb. n. The nematode fauna of fishes in cenotes of the Yucatan Peninsula shows its appurtenance to the Neotropical fauna with close affinities with that of fish nematodes from South America, but with a considerable degree of endemism. PMID:8774767

  9. Nematodes parasitic in fishes of cenotes (= sinkholes) of the Peninsula of Yucatan, Mexico. Part 1. Adults.

    PubMed

    Moravec, F; Vivas-Rodríguez, C; Scholz, T; Vargas-Vázquez, J; Mendoza-Franco, E; González-Solís, D

    1995-01-01

    The present paper comprises a systematic survey of adult nematodes collected from fishes from cenotes (= sinkholes) of the Peninsula of Yucatan, southeastern Mexico, in 1993-1994. Examinations of a total of 533 fishes (17 species) originating from 39 cenotes from the Mexican states of Yucatan and Quintana Roo revealed the presence of the following nine nematode species: Rhabdochona (Rhabdochona) kidderi, Procamallanus (Spirocamallanus) rebecae, P. (S.) neocaballeroi, Philometroides caudata, Hysterothylacium cenotue. Pseudocapillaria yucatanensis, Paracapillaria rhamdiae, P. teixerafreitasi and Capillostrongyloides sp. (only females). Four species (R. kidderi, P. rebecae, P. neocaballeroi and Capillostrongyloides sp.) are briefly described and illustrated and some problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. Taxonomic changes include Procamallanus (Spirocamallanus) neocaballeroi (Caballero-Deloya. 1977) comb. n. and Procamallanus (Spirocamallanus) rebecae (Andrade-Salas, Pineda-López et García-Magaña, 1994) comb. n. The nematode fauna of fishes in cenotes of the Yucatan Peninsula shows its appurtenance to the Neotropical fauna with close affinities with that of fish nematodes from South America, but with a considerable degree of endemism.

  10. Metagonimus yokogawai: metacercariae survey in fishes and its development to adult worms in various rodents.

    PubMed

    Li, Ming-Hsien; Huang, Hai-I; Chen, Pei-Lain; Huang, Chiung-Hua; Chen, Yu-Hsuan; Ooi, Hong-Kean

    2013-04-01

    A parasitological survey for Metagonimus yokogawai metacercariae was carried out by examining a total of 321 freshwater fish comprising of 7 species. Of the 321 fish samples examined, 182 (56.7%) were found to be infected with M. yokogawai metacercariae. The prevalence of M. yokogawai metacercariae in Opsariichthys pachycephalus was 93.4% (86/92), Zacco platypus 75.0% (30/40), Distoechodon turmirostris 61.3% (38/62), Varicorhinus barbatulus 56.5% (13/23), Hemibarbus labeo 33.3% (1/3), Acrossocheilus formosanus 15.9% (14/88), and 0% in Sinibrama macrops (0/13), respectively. This is the first record of M. yokogawai infection in Z. platypus, D. turmirostris, V. barbatulus, and H. labeo in Taiwan. The major site of predilection of the metacercariae in the fishes was in the scale, but some metacercariae were also observed in the flesh and fins. The M. yokogawai metacercariae were orally inoculated into mice, rat, gerbil, and golden hamster to study their infectivity and also to obtain the adult worms for taxonomic study. Worm recovery in hamsters was 75.3%, in mice was 70.0%, in rats was 23.3%, and in gerbils was 6.0%, respectively. Moreover, larger worms were recovered from the golden hamster. Golden hamster was thus found to be the most susceptible experimental rodent host for the infectivity study of Metagonimus. Besides M. yokogawai, metacercariae of Centrocestus formosanus was also observed in the fishes examined. PMID:23388732

  11. Ecological risks of dioxin and PCBs to fish populations: A modeling assessment

    SciTech Connect

    Munns, W.R. Jr.; Black, D.

    1994-12-31

    The US Environmental Protection Agency is reevaluating ecological risks associated with 2,3,7,8-tetrachlorodibenzo-p-dioxin and similar chemicals using biologically based exposure-response models. As part of this reevaluation, dioxin and PCB effects on reproductive and other demographic characteristics of the mummichog (Fundulus heteroclitus) were quantified by EPA`s Environmental Research Laboratory in Narragansett, RI. Data from laboratory studies of dietary exposure to dioxin and from surveys of populations collected from a heavily PCB-contaminated harbor located in the northeast United States were used to parameterize stage-classified population projection models. Exposure-response models were then developed to relate population growth effects to exposure concentration for use in risk quantification exercises. The population models were also used to evaluate the sensitivity of mummichog population dynamics to changes in demographic rates to identify appropriate toxicity test endpoints. This work provides ecological relevant information concerning the potential risks of chlorinated compounds to estuarine fish populations.

  12. Population divergence in fish elemental phenotypes associated with trophic phenotypes and lake trophic state.

    PubMed

    Tuckett, Quenton M; Kinnison, Michael T; Saros, Jasmine E; Simon, Kevin S

    2016-11-01

    Studies of ecological stoichiometry typically emphasize the role of interspecific variation in body elemental content and the effects of species or family identity. Recent work suggests substantial variation in body stoichiometry can also exist within species. The importance of this variation will depend on insights into its origins and consequences at various ecological scales, including the distribution of elemental phenotypes across landscapes and their role in nutrient recycling. We investigated whether trophic divergence can produce predictable patterns of elemental phenotypes among populations of an invasive fish, the white perch (Morone americana), and whether elemental phenotypes predict nutrient excretion. White perch populations exhibited a gradient of trophic phenotypes associated with landscape-scale variation in lake trophic state. Perch body chemistry varied considerably among lakes (from 0.09 for % C to 0.31-fold for % P) casting doubt on the assumption of homogenous elemental phenotypes. This variation was correlated with divergence in fish body shape and other trophic traits. Elemental phenotypes covaried (r (2) up to 0.84) with lake trophic state. This covariation likely arose in contemporary time since many of these perch populations were introduced in the last century and the trophic state in many of the lakes has changed in the past few decades. Nutrient excretion varied extensively among populations, but was not readily related to fish body chemistry or lake trophic state. This suggests that predictable patterns of fish body composition can arise quickly through trophic specialization to lake conditions, but such elemental phenotypes may not translate to altered nutrient recycling by fish.

  13. Prevalence of voice quality deviations in the normal adult population.

    PubMed

    Brindle, B R; Morris, H L

    1979-11-01

    The purpose of this study was to determine the prevalence of voice quality deviations in a normal adult population. One-hundred twelve subjects, aged 17 to 80, read a short paragraph aloud into a high-fidelity tape recorder and completed a case history questionnaire. A group of 11 pretrained judges rated overall performance of each taped sample on a seven-point equal-appearing intervals scale, then designated those quality components which contributed toward deviant ratings. Eighty-two percent of the group received a mean severity rating lower than 1.99; 16% had a rating between 2.00 and 2.99; and 2% was assigned a mean rating higher than 3.00.

  14. Populations of a cyprinid fish are self-sustaining despite widespread feminization of males

    PubMed Central

    2014-01-01

    Background Treated effluents from wastewater treatment works can comprise a large proportion of the flow of rivers in the developed world. Exposure to these effluents, or the steroidal estrogens they contain, feminizes wild male fish and can reduce their reproductive fitness. Long-term experimental exposures have resulted in skewed sex ratios, reproductive failures in breeding colonies, and population collapse. This suggests that environmental estrogens could threaten the sustainability of wild fish populations. Results Here we tested this hypothesis by examining population genetic structures and effective population sizes (Ne) of wild roach (Rutilus rutilus L.) living in English rivers contaminated with estrogenic effluents. Ne was estimated from DNA microsatellite genotypes using approximate Bayesian computation and sibling assignment methods. We found no significant negative correlation between Ne and the predicted estrogen exposure at 28 sample sites. Furthermore, examination of the population genetic structure of roach in the region showed that some populations have been confined to stretches of river with a high proportion of estrogenic effluent for multiple generations and have survived, apparently without reliance on immigration of fish from less polluted sites. Conclusions These results demonstrate that roach populations living in some effluent-contaminated river stretches, where feminization is widespread, are self-sustaining. Although we found no evidence to suggest that exposure to estrogenic effluents is a significant driving factor in determining the size of roach breeding populations, a reduction in Ne of up to 65% is still possible for the most contaminated sites because of the wide confidence intervals associated with the statistical model. PMID:24417977

  15. Surface anatomy and anatomical planes in the adult turkish population.

    PubMed

    Uzun, C; Atman, E D; Ustuner, E; Mirjalili, S A; Oztuna, D; Esmer, T S

    2016-03-01

    Surface anatomy and anatomical planes are widely used in education and clinical practice. The planes are largely derived from cadaveric studies and their projections on the skin show discrepancies between and within anatomical reference textbooks. In this study, we reassessed the accuracy of common thoracic and abdominopelvic anatomical planes using computed tomography (CT) imaging in the live adult Turkish population. After patients with distorting pathologies had been excluded, CT images of 150 supine patients at the end tidal inspiration were analyzed. Sternal angle, transpyloric, subcostal, supracristal and pubic crest planes and their relationships to anatomical structures were established by dual consensus. The tracheal bifurcation, azygos vein/superior vena cava (SVC) junction and pulmonary bifurcation were usually below the sternal angle while the concavity of the aortic arch was generally within the plane. The tip of the tenth rib, the superior mesenteric artery and the portal vein were usually within the transpyloric plane while the renal hila and the fundus of the gallbladder were below it. The inferior mesenteric artery was below the subcostal plane and the aortic bifurcation was below the supracristal plane in most adults. Projectional surface anatomy is fundamental to medical education and clinical practice. Modern cross-sectional imaging techniques allow large groups of live patients to be examined. Classic textbook information regarding anatomy needs to be reviewed and updated using the data gathered from these recent studies, taking ethnic differences into consideration.

  16. Anthropometric data of adult wheelchair users for Mexican population.

    PubMed

    Lucero-Duarte, Karla; de la Vega-Bustillos, Enrique; López-Millán, Francisco; Soto-Félix, Selene

    2012-01-01

    The aim of the study was to obtain anthropometric data of adult wheelchair users at Mexico. This study count with 108 disabled people (56 men and 52 women) using the wheelchair and having the upper extremities sufficiently efficient to perform professional activities. The subjects were aged 18-60. From the measurements obtained, it can be said that in each of these measures was observed that men have larger dimensions than women, except for body depth, in which women had a slightly greater difference. When comparing the data in this study against other studies it shows that there is a significant difference between the averages of these studies. Similar results were obtained when comparing our data against data of standard population. Anthropometric data obtained through this study appear to be the only of this kind in Mexico and showed significant differences between measures of disabled persons and standard persons. the use of these data may be helpful for the proper design of workstations designed for use by adults who use.

  17. High population density enhances recruitment and survival of a harvested coral reef fish.

    PubMed

    Wormald, Clare L; Steele, Mark A; Forrester, Graham E

    2013-03-01

    A negative relationship between population growth and population density (direct density dependence) is necessary for population regulation and is assumed in most models of harvested populations. Experimental tests for density dependence are lacking for large-bodied, harvested fish because of the difficulty of manipulating population density over large areas. We studied a harvested coral reef fish, Lutjanus apodus (schoolmaster snapper), using eight large, isolated natural reefs (0.4-1.6 ha) in the Bahamas as replicates. An initial observational test for density dependence was followed by a manipulation of population density. The manipulation weakened an association between density and shelter-providing habitat features and revealed a positive effect of population density on recruitment and survival (inverse density dependence), but no effect of density on somatic growth. The snappers on an individual reef were organized into a few shoals, and we hypothesize that large shoals on high-density reefs were less vulnerable to large piscivores (groupers and barracudas) than the small shoals on low-density reefs. Reductions in predation risk for individuals in large social groups are well documented, but because snapper shoals occupied reefs the size of small marine reserves, these ecological interactions may influence the outcome of management actions. PMID:23634588

  18. Connectivity, passability and heterogeneity interact to determine fish population persistence in river networks

    PubMed Central

    Samia, Yasmine; Lutscher, Frithjof; Hastings, Alan

    2015-01-01

    The movement of fish in watersheds is frequently inhibited by human-made migration barriers such as dams or culverts. The resulting lack of connectivity of spatial subpopulations is often cited as a cause for observed population decline. We formulate a matrix model for a spatially distributed fish population in a watershed, and we investigate how location and other characteristics of a single movement barrier impact the asymptotic growth rate of the population. We find that while population growth rate often decreases with the introduction of a movement obstacle, it may also increase due to a ‘retention effect’. Furthermore, obstacle mortality greatly affects population growth rate. In practice, different connectivity indices are used to predict population effects of migration barriers, but the relation of these indices to population growth rates in demographic models is often unclear. When comparing our results with the dentritic connectivity index, we see that the index captures neither the retention effect nor the influences of obstacle mortality. We argue that structural indices cannot entirely replace more detailed demographic models to understand questions of persistence and extinction. We advocate the development of novel functional indices and characteristics. PMID:26311313

  19. [The economical and evolutionary aspects of the optimal catch of the fish population].

    PubMed

    Il'ichev, V G

    2003-01-01

    The natural interpretation of population value (internal cost) is used for the common mathematical problem of population exploitation. It is suggested that the population owner--the state--can use internal costs as a tax on fish caught by holders (fishermen). It turns out that such a tax outline make fisherman to establish an optimal long-term strategy of catch. Moreover, if there is several fishermen' the special tax, which makes them to be consistent with common cooperative strategy, can be worked out. According to the proposed hypothesis the changes in internal costs can be used as an adaptive response to the "demand and supply" deformation of the exploited population. The concept of "ecological-economical" niche (habitat + place of sale) was proposed to characterize the exploited population. Computer calculations revealed the specific variant of Gause principle: the co-existing of two similar populations is impossible within single "ecologic-economical" niche. On the contrary, exploited similar populations show co-existence while fish is sailed on different markets.

  20. Adaptive divergence between lake and stream populations of an East African cichlid fish.

    PubMed

    Theis, Anya; Ronco, Fabrizia; Indermaur, Adrian; Salzburger, Walter; Egger, Bernd

    2014-11-01

    Divergent natural selection acting in different habitats may build up barriers to gene flow and initiate speciation. This speciation continuum can range from weak or no divergence to strong genetic differentiation between populations. Here, we focus on the early phases of adaptive divergence in the East African cichlid fish Astatotilapia burtoni, which occurs in both Lake Tanganyika (LT) and inflowing rivers. We first assessed the population structure and morphological differences in A. burtoni from southern LT. We then focused on four lake-stream systems and quantified body shape, ecologically relevant traits (gill raker and lower pharyngeal jaw) as well as stomach contents. Our study revealed the presence of several divergent lake-stream populations that rest at different stages of the speciation continuum, but show the same morphological and ecological trajectories along the lake-stream gradient. Lake fish have higher bodies, a more superior mouth position, longer gill rakers and more slender pharyngeal jaws, and they show a plant/algae and zooplankton-biased diet, whereas stream fish feed more on snails, insects and plant seeds. A test for reproductive isolation between closely related lake and stream populations did not detect population-assortative mating. Analyses of F1 offspring reared under common garden conditions indicate that the detected differences in body shape and gill raker length do not constitute pure plastic responses to different environmental conditions, but also have a genetic basis. Taken together, the A. burtoni lake-stream system constitutes a new model to study the factors that enhance and constrain progress towards speciation in cichlid fishes.

  1. Removal of nonnative fish results in population expansion of a declining amphibian (mountain yellow-legged frog, Rana muscosa).

    PubMed

    Knapp, Roland A; Boiano, Daniel M; Vredenburg, Vance T

    2007-02-01

    The mountain yellow-legged frog (Rana muscosa) was once a common inhabitant of the Sierra Nevada (California, USA), but has declined precipitously during the past century due in part to the introduction of nonnative fish into naturally fishless habitats. The objectives of the current study were to describe (1) the effect of fish removal from three lakes (located in two watersheds) on the small, remnant R. muscosa populations inhabiting those lakes, and (2) the initial development of metapopulation structure in each watershed as R. muscosa from expanding populations in fish-removal lakes dispersed to adjacent habitats. At all three fish-removal lakes, R. muscosa population densities increased significantly following the removal of predatory fish. The magnitude of these increases was significantly greater than that observed over the same time period in R. muscosa populations inhabiting control lakes that remained in their natural fishless condition. Following these population increases, R. muscosa dispersed to adjacent suitable (but unoccupied) sites, moving between 200 and 900 m along streams or across dry land. Together, these results suggest that large-scale removal of introduced fish could result in at least partial reversal of the decline of R. muscosa. Continued monitoring of R. muscosa at the fish-removal sites will be necessary to determine whether the positive effects of fish eradication are sustained over the long-term, especially in light of the increasingly important role played by an emerging infectious disease (chytridiomycosis, caused by Batrachochytrium dendrobatidis) in influencing R. muscosa populations. PMID:17396156

  2. Prevalence of Dental Caries in Kosovar Adult Population

    PubMed Central

    Begzati, Agim; Kelmendi, Jeta; Ilijazi, Donika; Kqiku, Lumnije

    2016-01-01

    Objectives. The aim of this study was to assess the prevalence of dental caries in the Kosovar adult population. Materials and Methods. A cross-sectional study in Kosovo was conducted examining 9387 patients, aged 18 upwards, between January 2010 and December 2011. Clinical evaluation was done using WHO criteria for evaluation of dental health status and data collection. Results. The prevalence of caries for the whole study was 72.80%. The mean DMFT index was 9.61 (±5.12) in the 18–34-year age group, 11.6 (±6.42) in the 35–44-year age group, 13.68 (±8.12) among the 45–64-year age group, 17.98 (±9.81) in the 65–74-year age group, and 23.19 (±9.41) in the age group of 75+ years, respectively. A significant difference of mean DMFT and its each component was observed between the ages (P < 0.001). Conclusion. This study comes out with the significant levels of dental caries among young Kosovar population (18–34 years old). PMID:27516774

  3. Diabetes Mellitus and Its Correlates in an Iranian Adult Population

    PubMed Central

    Kamangar, Farin; Poutschi, Hossein; Islami, Farhad; Abnet, Christian C.; Freedman, Neal D.; Taylor, Philip R.; Pharoah, Paul; Boffetta, Paolo; Brennan, Paul J.; Dawsey, Sanford M.; Malekzadeh, Reza; Etemadi, Arash

    2011-01-01

    The rising epidemic of diabetes imposes a substantial economic burden on the Middle East. Using baseline data from a population based cohort study, we aimed to identify the correlates of diabetes mellitus (DM) in a mainly rural population from Iran. Between 2004 and 2007, 50044 adults between 30 and 87 years old from Golestan Province located in Northeast Iran were enrolled in the Golestan Cohort Study. Demographic and health-related information was collected using questionnaires. Individuals' body sizes at ages 15 and 30 were assessed by validated pictograms ranging from 1 (very lean) to 7 in men and 9 in women. DM diagnosis was based on the self-report of a physician's diagnosis. The accuracy of self-reported DM was evaluated in a subcohort of 3811 individuals using fasting plasma glucose level and medical records. Poisson regression with robust variance estimator was used to estimate prevalence ratios (PR's). The prevalence of self-reported DM standardized to the national and world population was 5.7% and 6.2%, respectively. Self-reported DM had 61.5% sensitivity and 97.6% specificity. Socioeconomic status was inversely associated with DM prevalence. Green tea and opium consumption increased the prevalence of DM. Obesity at all ages and extreme leanness in childhood increased diabetes prevalence. Being obese throughout life doubled DM prevalence in women (PR: 2.1; 95% CI: 1.8, 2.4). These findings emphasize the importance of improving DM awareness, improving general living conditions, and early lifestyle modifications in diabetes prevention. PMID:22053206

  4. EFFECTS OF BENZO[A]PYRENE EXPOSURE ON A FISH POPULATION RESISTANT TO THE TOXIC EFFECTS OF DIOXIN-LIKE COMPOUNDS

    EPA Science Inventory

    Effects of a model polycyclic aromatic hydrocarbon (PAH) were compared in populations of the estuarine fish Fundulus heteroclitus indigenous to a reference site and one highly contaminated with polychlorinated biphenyls (PCBs) and other compounds. The fish population resident to ...

  5. Increased extinction potential of insular fish populations with reduced life history variation and low genetic diversity.

    PubMed

    Hellmair, Michael; Kinziger, Andrew P

    2014-01-01

    Theoretical work has shown that reduced phenotypic heterogeneity leads to population instability and can increase extinction potential, yet few examples exist of natural populations that illustrate how varying levels expressed diversity may influence population persistence, particularly during periods of stochastic environmental fluctuation. In this study, we assess levels of expressed variation and genetic diversity among demographically independent populations of tidewater goby (Eucyclogobius newberryi), show that reductions in both factors typically coincide, and describe how low levels of diversity contribute to the extinction risk of these isolated populations. We illustrate that, for this annual species, continuous reproduction is a safeguard against reproductive failure by any one population segment, as natural, stochastically driven salinity increases frequently result in high mortality among juvenile individuals. Several study populations deviated from the natural pattern of year-round reproduction typical for the species, rendering those with severely truncated reproductive periods vulnerable to extinction in the event of environmental fluctuation. In contrast, demographically diverse populations are more likely to persist through such periods through the continuous presence of adults with broader physiological tolerance to abrupt salinity changes. Notably, we found a significant correlation between genetic diversity and demographic variation in the study populations, which could be the result of population stressors that restrict both of these diversity measures simultaneously, or suggestive of a causative relationship between these population characteristics. These findings demonstrate the importance of biocomplexity at the population level, and assert that the maintenance of diversity contributes to population resilience and conservation of this endangered species.

  6. Increased Extinction Potential of Insular Fish Populations with Reduced Life History Variation and Low Genetic Diversity

    PubMed Central

    Hellmair, Michael; Kinziger, Andrew P.

    2014-01-01

    Theoretical work has shown that reduced phenotypic heterogeneity leads to population instability and can increase extinction potential, yet few examples exist of natural populations that illustrate how varying levels expressed diversity may influence population persistence, particularly during periods of stochastic environmental fluctuation. In this study, we assess levels of expressed variation and genetic diversity among demographically independent populations of tidewater goby (Eucyclogobius newberryi), show that reductions in both factors typically coincide, and describe how low levels of diversity contribute to the extinction risk of these isolated populations. We illustrate that, for this annual species, continuous reproduction is a safeguard against reproductive failure by any one population segment, as natural, stochastically driven salinity increases frequently result in high mortality among juvenile individuals. Several study populations deviated from the natural pattern of year-round reproduction typical for the species, rendering those with severely truncated reproductive periods vulnerable to extinction in the event of environmental fluctuation. In contrast, demographically diverse populations are more likely to persist through such periods through the continuous presence of adults with broader physiological tolerance to abrupt salinity changes. Notably, we found a significant correlation between genetic diversity and demographic variation in the study populations, which could be the result of population stressors that restrict both of these diversity measures simultaneously, or suggestive of a causative relationship between these population characteristics. These findings demonstrate the importance of biocomplexity at the population level, and assert that the maintenance of diversity contributes to population resilience and conservation of this endangered species. PMID:25409501

  7. Higher freshwater fish and sea fish intake is inversely associated with colorectal cancer risk among Chinese population: a case-control study

    PubMed Central

    Xu, Ming; Fang, Yu-Jing; Chen, Yu-Ming; Lu, Min-Shan; Pan, Zhi-Zhong; Yan, Bo; Zhong, Xiao; Zhang, Cai-Xia

    2015-01-01

    The association between specific fish intake and colorectal cancer risk remains controversial. This study aimed to examine the association between specific fish intake and colorectal cancer risk in Chinese population in a large case control study. During July 2010 to November 2014, 1189 eligible colorectal cancer cases and 1189 frequency-matched controls (age and sex) completed in-person interviews. A validated food frequency questionnaire was used to estimate dietary intake. Multivariate logistical regression models were used to estimate the odds ratio (OR) and 95% confidence interval (95% CI) after adjusting for various confounders. A strong inverse association was found between freshwater fish intake and colorectal cancer risk. Compared with the lowest quartile, the highest quartile intake showed a risk reduction of 53% (OR 0.47, 95% CI = 0.36–0.60, Ptrend < 0.01) after adjustment for various confounders. The inverse association were also observed for sea fish (OR 0.79, 95%CI = 0.62–0.99, Ptrend < 0.01) and fresh fish (OR 0.49, 95%CI = 0.38–0.62, Ptrend < 0.01). No statistically significant association was found between dried/salted fish and shellfish intake and colorectal cancer risk. These results indicate that higher consumption of freshwater fish, sea fish and fresh fish is associated with a lower risk of colorectal caner. PMID:26264963

  8. Higher freshwater fish and sea fish intake is inversely associated with colorectal cancer risk among Chinese population: a case-control study.

    PubMed

    Xu, Ming; Fang, Yu-Jing; Chen, Yu-Ming; Lu, Min-Shan; Pan, Zhi-Zhong; Yan, Bo; Zhong, Xiao; Zhang, Cai-Xia

    2015-01-01

    The association between specific fish intake and colorectal cancer risk remains controversial. This study aimed to examine the association between specific fish intake and colorectal cancer risk in Chinese population in a large case control study. During July 2010 to November 2014, 1189 eligible colorectal cancer cases and 1189 frequency-matched controls (age and sex) completed in-person interviews. A validated food frequency questionnaire was used to estimate dietary intake. Multivariate logistical regression models were used to estimate the odds ratio (OR) and 95% confidence interval (95% CI) after adjusting for various confounders. A strong inverse association was found between freshwater fish intake and colorectal cancer risk. Compared with the lowest quartile, the highest quartile intake showed a risk reduction of 53% (OR 0.47, 95% CI = 0.36-0.60, Ptrend < 0.01) after adjustment for various confounders. The inverse association were also observed for sea fish (OR 0.79, 95%CI = 0.62-0.99, Ptrend < 0.01) and fresh fish (OR 0.49, 95%CI = 0.38-0.62, Ptrend < 0.01). No statistically significant association was found between dried/salted fish and shellfish intake and colorectal cancer risk. These results indicate that higher consumption of freshwater fish, sea fish and fresh fish is associated with a lower risk of colorectal caner.

  9. A moving target--incorporating knowledge of the spatial ecology of fish into the assessment and management of freshwater fish populations.

    PubMed

    Cooke, Steven J; Martins, Eduardo G; Struthers, Daniel P; Gutowsky, Lee F G; Power, Michael; Doka, Susan E; Dettmers, John M; Crook, David A; Lucas, Martyn C; Holbrook, Christopher M; Krueger, Charles C

    2016-04-01

    Freshwater fish move vertically and horizontally through the aquatic landscape for a variety of reasons, such as to find and exploit patchy resources or to locate essential habitats (e.g., for spawning). Inherent challenges exist with the assessment of fish populations because they are moving targets. We submit that quantifying and describing the spatial ecology of fish and their habitat is an important component of freshwater fishery assessment and management. With a growing number of tools available for studying the spatial ecology of fishes (e.g., telemetry, population genetics, hydroacoustics, otolith microchemistry, stable isotope analysis), new knowledge can now be generated and incorporated into biological assessment and fishery management. For example, knowing when, where, and how to deploy assessment gears is essential to inform, refine, or calibrate assessment protocols. Such information is also useful for quantifying or avoiding bycatch of imperiled species. Knowledge of habitat connectivity and usage can identify critically important migration corridors and habitats and can be used to improve our understanding of variables that influence spatial structuring of fish populations. Similarly, demographic processes are partly driven by the behavior of fish and mediated by environmental drivers. Information on these processes is critical to the development and application of realistic population dynamics models. Collectively, biological assessment, when informed by knowledge of spatial ecology, can provide managers with the ability to understand how and when fish and their habitats may be exposed to different threats. Naturally, this knowledge helps to better evaluate or develop strategies to protect the long-term viability of fishery production. Failure to understand the spatial ecology of fishes and to incorporate spatiotemporal data can bias population assessments and forecasts and potentially lead to ineffective or counterproductive management actions

  10. A moving target--incorporating knowledge of the spatial ecology of fish into the assessment and management of freshwater fish populations.

    PubMed

    Cooke, Steven J; Martins, Eduardo G; Struthers, Daniel P; Gutowsky, Lee F G; Power, Michael; Doka, Susan E; Dettmers, John M; Crook, David A; Lucas, Martyn C; Holbrook, Christopher M; Krueger, Charles C

    2016-04-01

    Freshwater fish move vertically and horizontally through the aquatic landscape for a variety of reasons, such as to find and exploit patchy resources or to locate essential habitats (e.g., for spawning). Inherent challenges exist with the assessment of fish populations because they are moving targets. We submit that quantifying and describing the spatial ecology of fish and their habitat is an important component of freshwater fishery assessment and management. With a growing number of tools available for studying the spatial ecology of fishes (e.g., telemetry, population genetics, hydroacoustics, otolith microchemistry, stable isotope analysis), new knowledge can now be generated and incorporated into biological assessment and fishery management. For example, knowing when, where, and how to deploy assessment gears is essential to inform, refine, or calibrate assessment protocols. Such information is also useful for quantifying or avoiding bycatch of imperiled species. Knowledge of habitat connectivity and usage can identify critically important migration corridors and habitats and can be used to improve our understanding of variables that influence spatial structuring of fish populations. Similarly, demographic processes are partly driven by the behavior of fish and mediated by environmental drivers. Information on these processes is critical to the development and application of realistic population dynamics models. Collectively, biological assessment, when informed by knowledge of spatial ecology, can provide managers with the ability to understand how and when fish and their habitats may be exposed to different threats. Naturally, this knowledge helps to better evaluate or develop strategies to protect the long-term viability of fishery production. Failure to understand the spatial ecology of fishes and to incorporate spatiotemporal data can bias population assessments and forecasts and potentially lead to ineffective or counterproductive management actions.

  11. A moving target—incorporating knowledge of the spatial ecology of fish into the assessment and management of freshwater fish populations

    USGS Publications Warehouse

    Cooke, Steven J.; Martins, Eduardo G; Struthers, Daniel P; Gutowsky, Lee F G; Powers, Michael H.; Doka, Susan E; Dettmers, John M.; Crook, David A; Lucas, Martyn C.; Holbrook, Christopher; Krueger, Charles C.

    2016-01-01

    Freshwater fish move vertically and horizontally through the aquatic landscape for a variety of reasons, such as to find and exploit patchy resources or to locate essential habitats (e.g., for spawning). Inherent challenges exist with the assessment of fish populations because they are moving targets. We submit that quantifying and describing the spatial ecology of fish and their habitat is an important component of freshwater fishery assessment and management. With a growing number of tools available for studying the spatial ecology of fishes (e.g., telemetry, population genetics, hydroacoustics, otolith microchemistry, stable isotope analysis), new knowledge can now be generated and incorporated into biological assessment and fishery management. For example, knowing when, where, and how to deploy assessment gears is essential to inform, refine, or calibrate assessment protocols. Such information is also useful for quantifying or avoiding bycatch of imperiled species. Knowledge of habitat connectivity and usage can identify critically important migration corridors and habitats and can be used to improve our understanding of variables that influence spatial structuring of fish populations. Similarly, demographic processes are partly driven by the behavior of fish and mediated by environmental drivers. Information on these processes is critical to the development and application of realistic population dynamics models. Collectively, biological assessment, when informed by knowledge of spatial ecology, can provide managers with the ability to understand how and when fish and their habitats may be exposed to different threats. Naturally, this knowledge helps to better evaluate or develop strategies to protect the long-term viability of fishery production. Failure to understand the spatial ecology of fishes and to incorporate spatiotemporal data can bias population assessments and forecasts and potentially lead to ineffective or counterproductive management actions.

  12. Boule Is Present in Fish and Bisexually Expressed in Adult and Embryonic Germ Cells of Medaka

    PubMed Central

    Xu, Hongyan; Li, Zhendong; Li, Mingyou; Wang, Li; Hong, Yunhan

    2009-01-01

    Background The DAZ family genes boule, daz and dazl encode RNA binding proteins essential for fertility of diverse animals including human. dazl has bisexual expression in both mitotic and meiotic germ cells, whereas daz has male premeiotic expression, and boule is largely a unisexual meiotic regulator. Although boule has been proposed as the ancestor for dazl/daz by gene duplication, it has been identified only in invertebrates and mammals. It has, however, remained unclear when and how the DAZ family has evolved in vertebrates. Methodology and Principal Findings This study was aimed at identifying and characterizing the DAZ family genes in fish as the basal vertebrate. We show that boule and dazl coexist in medaka and stickleback. Similar to the medaka dazl (Odazl), the medaka boule (Obol) is maternally supplied and segregates with primordial germ cells. Surprisingly, Obol is expressed in adult germ cells at pre-meiotic and meiotic stages of spermatogenesis and oogenesis. However, the maximal meiotic Obol expression in spermatocytes contrasts with the predominant pre-meiotic Odazl expression in spermatogonia, and the diffuse cytoplasmic Obol distribution in early oocytes contrasts with the Odazl concentration in the Balbinani's body. Conclusions The identification of fish boule and dazl genes provides direct evidence for the early gene duplication during vertebrate evolution. Our finding that Obol exhibits bisexual expression in both embryonic and adult germ cells considerably extends the diversity of boule expression patterns and offers a new insight into the evolutions of DAZ family members, expression patterns and functions in animal fertility. PMID:19564913

  13. Population dynamics of wetland fishes: Spatio-temporal patterns synchronized by hydrological disturbance?

    USGS Publications Warehouse

    Ruetz, C. R.; Trexler, J.C.; Jordan, F.; Loftus, W.F.; Perry, S.A.

    2005-01-01

    1. Drought is a natural disturbance that can cause widespread mortality of aquatic organisms in wetlands. We hypothesized that seasonal drying of marsh surfaces (i.e. hydrological disturbance) shapes spatio-temporal patterns of fish populations. 2. We tested whether population dynamics of fishes were synchronized by hydrological disturbance (Moran effect) or distance separating study sites (dispersal). Spatio-temporal patterns were examined in local populations of five abundant species at 17 sites (sampled five times per year from 1996 to 2001) in a large oligotrophic wetland. 3. Fish densities differed significantly across spatio-temporal scales for all species. For all species except eastern mosquitofish (Gambusia holbrooki), a significant portion of spatio-temporal variation in density was attributed to drying events (used as a covariate). 4. We observed three patterns of response to hydrological disturbance. Densities of bluefin killifish (Lucania goodei), least killifish (Heterandria formosa), and golden top-minnow (Fundulus chrysotus) were usually lowest after a dry down and recovered slowly. Eastern mosquitofish showed no distinct response to marsh drying (i.e. they recovered quickly). Flagfish (Jordanella floridae) density was often highest after a dry down and then declined. Population growth after a dry down was often asymptotic for bluefin killifish and golden topminnow, with greatest asymptotic density and longest time to recovery at sites that dried infrequently. 5. Fish population dynamics were synchronized by hydrological disturbance (independent of distance) and distance separating study sites (independent of hydrological disturbance). Our ability to separate the relative importance of the Moran effect from dispersal was strengthened by a weak association between hydrological synchrony and distance among study sites. Dispersal was the primary mechanism for synchronous population dynamics of flagfish, whereas hydrological disturbance was the primary

  14. Successional change in the Lake Superior fish community: population trends in ciscoes, rainbow smelt, and lake trout, 1958-2008

    USGS Publications Warehouse

    Gorman, Owen T.

    2012-01-01

    The Lake Superior fish community underwent massive changes in the second half of the 20th century. Those changes are largely reflected in changes in abundance of the adults of principal prey species, the ciscoes (Coregonus spp.), the invasive rainbow smelt (Osmerus mordax), and the principal predator, lake trout (Salvelinus namaycush). To better understand changes in species abundances, a comprehensive series of gillnet and bottom trawl data collected from 1958 to 2008 were examined. In the late 1950s/early 1960s, smelt abundance was at its maximum, wild lake trout was at its minimum, and an abundance of hatchery lake trout was increasing rapidly. The bloater (Coregonus hoyi) was the prevalent cisco in the lake; abundance was more than 300% greater than the next most abundant cisco, shortjaw cisco (C. zenithicus), followed by kiyi (C. kiyi) and lake cisco (C. artedi). By the mid-1960s, abundance of hatchery lake trout was nearing maximum, smelt abundance was beginning to decline, and abundances of all ciscoes declined, but especially that of shortjaw cisco and kiyi. By the late 1970s, recovery of wild lake trout stocks was well underway and abundances of hatchery lake trout and smelt were declining and the ciscoes were reaching their nadir. During 1980–1990, the fish community underwent a dramatic shift in organization and structure. The rapid increase in abundance of wild lake trout, concurrent with a rapid decline in hatchery lake trout, signaled the impending recovery. Rainbow smelt abundance dropped precipitously and within four years, lake cisco and bloater populations rebounded on the heels of a series of strong recruitment events. Kiyi populations showed signs of recovery by 1989, and shortjaw by 2000, though well below historic maximum abundances. High abundance of adult smelt prior to 1980 appears to be the only factor linked to recruitment failure in the ciscoes. Life history traits of the cisco species were examined to better understand their different

  15. Dietary intakes of fats, fish and nuts and olfactory impairment in older adults.

    PubMed

    Gopinath, Bamini; Sue, Carolyn M; Flood, Victoria M; Burlutsky, George; Mitchell, Paul

    2015-07-01

    It is unclear whether lifestyle modifications, such as dietary changes, should be advocated to prevent olfactory dysfunction. We investigated the association between dietary intakes of fats (saturated, mono-unsaturated and polyunsaturated fats, and cholesterol) and related food groups (nuts, fish, butter, margarine) with olfactory impairment. There were 1331 and 667 participants (older than 60 years) at baseline and 5-year follow-up, respectively, with complete olfaction and dietary data. Dietary data were collected using a validated semi-quantitative FFQ. Olfaction was measured using the San Diego Odor Identification Test. In a cross-sectional analysis of baseline data, those in the highest v. lowest quartile of n-6 PUFA intake had reduced odds of having any olfactory impairment, multivariable-adjusted OR 0.66 (95% CI 0.44, 0.97), P for trend = 0.06. Participants in the highest v. lowest quartile of margarine consumption had a 65% reduced odds of having moderate/severe olfactory impairment (P for trend = 0.02). Participants in the highest quartile compared to the lowest quartile (reference) of nut consumption had a 46% (P for trend = 0.01) and 58% (P for trend = 0.001) reduced odds of having any or mild olfactory impairment, respectively. Older adults in the highest v. lowest quartile of fish consumption had 35% (P for trend = 0.03) and 50% (P for trend = 0.01) reduced likelihood of having any or mild olfactory impairment, respectively. In longitudinal analyses, a marginally significant association was observed between nut consumption and incidence of any olfactory impairment, highest v. lowest quartile of nut consumption: OR 0.61 (95% CI 0.37, 1.00). Older adults with the highest consumption of nuts and fish had reduced odds of olfactory impairment, independent of potential confounding variables.

  16. p53 Mutation suppresses adult neurogenesis in medaka fish (Oryzias latipes)

    SciTech Connect

    Isoe, Yasuko; Okuyama, Teruhiro; Taniguchi, Yoshihito; Kubo, Takeo; Takeuchi, Hideaki

    2012-07-13

    Highlights: Black-Right-Pointing-Pointer Progenitor migration is accompanied by an increase in their numbers in the adult brain. Black-Right-Pointing-Pointer p53 Mutation suppressed an increase in the number of the migrated progenitors. Black-Right-Pointing-Pointer The decreased progenitor number is not due to enhanced cell death. Black-Right-Pointing-Pointer p53 Mutation did not affect proliferation of stem cells. -- Abstract: Tumor suppressor p53 negatively regulates self-renewal of neural stem cells in the adult murine brain. Here, we report that the p53 null mutation in medaka fish (Oryzias latipes) suppressed neurogenesis in the telencephalon, independent of cell death. By using 5-bromo-29-deoxyuridine (BrdU) immunohistochemistry, we identified 18 proliferation zones in the brains of young medaka fish; in situ hybridization showed that p53 was expressed selectively in at least 12 proliferation zones. We also compared the number of BrdU-positive cells present in the whole telencephalon of wild-type (WT) and p53 mutant fish. Immediately after BrdU exposure, the number of BrdU-positive cells did not differ significantly between them. One week after BrdU-exposure, the BrdU-positive cells migrated from the proliferation zone, which was accompanied by an increased number in the WT brain. In contrast, no significant increase was observed in the p53 mutant brain. Terminal deoxynucleotidyl transferase (dUTP) nick end-labeling revealed that there was no significant difference in the number of apoptotic cells in the telencephalon of p53 mutant and WT medaka, suggesting that the decreased number of BrdU-positive cells in the mutant may be due to the suppression of proliferation rather than the enhancement of neural cell death. These results suggest that p53 positively regulates neurogenesis via cell proliferation.

  17. Season of birth and population schizotypy: Results from a large sample of the adult general population.

    PubMed

    Konrath, Lisa; Beckius, Danièle; Tran, Ulrich S

    2016-08-30

    Although the last years have seen an increasing interest in schizotypy and its pathogenesis, there exist only a handful of studies examining the possible interaction between season of birth (SOB) and schizotypic personality structure. Available research used differing screening instruments, rendering comparisons between studies difficult, and sample sizes in adult populations may have been too small to detect a mild effect. The current study examined the association between SOB and psychometric schizotypy in the so far single-largest sample from the adult general population (N=8114), balanced for men and women, and utilizing a valid and reliable instrument for the assessment of schizotypy. Using the 12 most informative items of the Schizotypal Personality Questionnaire Brief, we obtained evidence of a small, but significant, effect of late winter and early spring births (February/March) on psychometric schizotypy. The effect was not constrained to women, but affected men and women alike. The observed association between SOB and schizotypy appears compatible with seasonal variations of temperature and influenza prevalence, and with recent evidence on seasonal variability in the activity of the human immune system. Our findings lend support to the continuum hypothesis of schizotypy and schizophrenia, for which SOB effects have been previously established. PMID:27310922

  18. Population genomics of marine fishes: identifying adaptive variation in space and time.

    PubMed

    Nielsen, Einar E; Hemmer-Hansen, Jakob; Larsen, Peter Foged; Bekkevold, Dorte

    2009-08-01

    Studies of adaptive evolution have experienced a recent revival in population genetics of natural populations and there is currently much focus on identifying genomic signatures of selection in space and time. Insights into local adaptation, adaptive response to global change and evolutionary consequences of selective harvesting can be generated through population genomics studies, allowing the separation of the effects invoked by neutral processes (drift-migration) from those due to selection. Such knowledge is important not only for improving our basic understanding of natural as well as human-induced evolutionary processes, but also for predicting future trajectories of biodiversity and for setting conservation priorities. Marine fishes possess a number of features rendering them well suited for providing general insights into adaptive genomic evolution in natural populations. These include well-described population structures, substantial and rapidly developing genomic resources and abundant archived samples enabling temporal studies. Furthermore, superior possibilities for conducting large-scale experiments under controlled conditions, due to the economic resources provided by the large and growing aquaculture industry, hold great promise for utilizing recent technological developments. Here, we review achievements in marine fish genomics to date and highlight potential avenues for future research, which will provide both general insights into evolution in high gene flow species, as well as specific knowledge which can lead to improved management of marine organisms.

  19. Population Pharmacokinetics of Benznidazole in Adult Patients with Chagas Disease

    PubMed Central

    Aldasoro, E.; Guerrero, L.; Posada, E.; Serret, N.; Mejía, T.; Urbina, J. A.; Gascón, J.

    2015-01-01

    The aim of the present study was to build a population pharmacokinetic (popPK) model to characterize benznidazole (BNZ) pharmacokinetics in adults with chronic Chagas disease. This study was a prospective, open-label, single-center clinical trial approved by the local ethics committee. Patients received BNZ at 2.5 mg/kg of body weight/12 h (Abarax, Elea Laboratory, Argentina) for 60 days. Plasma BNZ samples were taken several times during the study and analyzed by high-performance liquid chromatography with UV-visible detection (HPLC-UV). The popPK analysis was done with NONMEMv.7.3. Demographic and biological data were tested as covariates. Intraindividual, interoccasion, and residual variabilities were modeled. Internal and external validations were completed to assess the robustness of the model. Later on, simulations were performed to generate BNZ concentration-time course profiles for different dosage regimens. A total of 358 plasma BNZ concentrations from 39 patients were included in the analysis. A one-compartment PK model characterized by clearance (CL/F) and the apparent volume of distribution (V/F), with first-order absorption (Ka) and elimination, adequately described the data (CL/F, 1.73 liters/h; V/F, 89.6 liters; and Ka, 1.15 h−1). No covariates were found to be significant for CL/F and V/F. Internal and external validations of the final model showed adequate results. Data from simulations revealed that a dose of 2.5 mg/kg/12 h might lead to overexposure in most patients. A lower dose (2.5 mg/kg/24 h) was able to achieve trough BNZ plasma concentrations within the accepted therapeutic range of 3 to 6 mg/liter. In summary, we developed a population PK model for BNZ in adults with chronic Chagas disease. Dosing simulations showed that a BNZ dose of 2.5 mg/kg/24 h will adequately keep BNZ trough plasma concentrations within the recommended target range for the majority of patients. (This study has been registered at EudraCT under number 2011

  20. Contrasting Genetic Structure among Populations of Two Amphidromous Fish Species (Sicydiinae) in the Central West Pacific

    PubMed Central

    Taillebois, Laura; Castelin, Magalie; Ovenden, Jennifer R.; Bonillo, Céline; Keith, Philippe

    2013-01-01

    Both present-day and past processes can shape connectivity of populations. Pleistocene vicariant events and dispersal have shaped the present distribution and connectivity patterns of aquatic species in the Indo-Pacific region. In particular, the processes that have shaped distribution of amphidromous goby species still remain unknown. Previous studies show that phylogeographic breaks are observed between populations in the Indian and Pacific Oceans where the shallow Sunda shelf constituted a geographical barrier to dispersal, or that the large spans of open ocean that isolate the Hawaiian or Polynesian Islands are also barriers for amphidromous species even though they have great dispersal capacity. Here we assess past and present genetic structure of populations of two amphidromous fish (gobies of the Sicydiinae) that are widely distributed in the Central West Pacific and which have similar pelagic larval durations. We analysed sections of mitochondrial COI, Cytb and nuclear Rhodospine genes in individuals sampled from different locations across their entire known range. Similar to other Sicydiinae fish, intraspecific mtDNA genetic diversity was high for all species (haplotype diversity between 0.9–0.96). Spatial analyses of genetic variation in Sicyopus zosterophorum demonstrated strong isolation across the Torres Strait, which was a geologically intermittent land barrier linking Australia to Papua New Guinea. There was a clear genetic break between the northwestern and the southwestern clusters in Si. zosterophorum (φST = 0.67502 for COI) and coalescent analyses revealed that the two populations split at 306 Kyr BP (95% HPD 79–625 Kyr BP), which is consistent with a Pleistocene separation caused by the Torres Strait barrier. However, this geographical barrier did not seem to affect Sm. fehlmanni. Historical and demographic hypotheses are raised to explain the different patterns of population structure and distribution between these species. Strategies

  1. Contrasting genetic structure among populations of two amphidromous fish species (Sicydiinae) in the Central West Pacific.

    PubMed

    Taillebois, Laura; Castelin, Magalie; Ovenden, Jennifer R; Bonillo, Céline; Keith, Philippe

    2013-01-01

    Both present-day and past processes can shape connectivity of populations. Pleistocene vicariant events and dispersal have shaped the present distribution and connectivity patterns of aquatic species in the Indo-Pacific region. In particular, the processes that have shaped distribution of amphidromous goby species still remain unknown. Previous studies show that phylogeographic breaks are observed between populations in the Indian and Pacific Oceans where the shallow Sunda shelf constituted a geographical barrier to dispersal, or that the large spans of open ocean that isolate the Hawaiian or Polynesian Islands are also barriers for amphidromous species even though they have great dispersal capacity. Here we assess past and present genetic structure of populations of two amphidromous fish (gobies of the Sicydiinae) that are widely distributed in the Central West Pacific and which have similar pelagic larval durations. We analysed sections of mitochondrial COI, Cytb and nuclear Rhodospine genes in individuals sampled from different locations across their entire known range. Similar to other Sicydiinae fish, intraspecific mtDNA genetic diversity was high for all species (haplotype diversity between 0.9-0.96). Spatial analyses of genetic variation in Sicyopus zosterophorum demonstrated strong isolation across the Torres Strait, which was a geologically intermittent land barrier linking Australia to Papua New Guinea. There was a clear genetic break between the northwestern and the southwestern clusters in Si. zosterophorum (φST = 0.67502 for COI) and coalescent analyses revealed that the two populations split at 306 Kyr BP (95% HPD 79-625 Kyr BP), which is consistent with a Pleistocene separation caused by the Torres Strait barrier. However, this geographical barrier did not seem to affect Sm. fehlmanni. Historical and demographic hypotheses are raised to explain the different patterns of population structure and distribution between these species. Strategies

  2. Contrasting genetic structure among populations of two amphidromous fish species (Sicydiinae) in the Central West Pacific.

    PubMed

    Taillebois, Laura; Castelin, Magalie; Ovenden, Jennifer R; Bonillo, Céline; Keith, Philippe

    2013-01-01

    Both present-day and past processes can shape connectivity of populations. Pleistocene vicariant events and dispersal have shaped the present distribution and connectivity patterns of aquatic species in the Indo-Pacific region. In particular, the processes that have shaped distribution of amphidromous goby species still remain unknown. Previous studies show that phylogeographic breaks are observed between populations in the Indian and Pacific Oceans where the shallow Sunda shelf constituted a geographical barrier to dispersal, or that the large spans of open ocean that isolate the Hawaiian or Polynesian Islands are also barriers for amphidromous species even though they have great dispersal capacity. Here we assess past and present genetic structure of populations of two amphidromous fish (gobies of the Sicydiinae) that are widely distributed in the Central West Pacific and which have similar pelagic larval durations. We analysed sections of mitochondrial COI, Cytb and nuclear Rhodospine genes in individuals sampled from different locations across their entire known range. Similar to other Sicydiinae fish, intraspecific mtDNA genetic diversity was high for all species (haplotype diversity between 0.9-0.96). Spatial analyses of genetic variation in Sicyopus zosterophorum demonstrated strong isolation across the Torres Strait, which was a geologically intermittent land barrier linking Australia to Papua New Guinea. There was a clear genetic break between the northwestern and the southwestern clusters in Si. zosterophorum (φST = 0.67502 for COI) and coalescent analyses revealed that the two populations split at 306 Kyr BP (95% HPD 79-625 Kyr BP), which is consistent with a Pleistocene separation caused by the Torres Strait barrier. However, this geographical barrier did not seem to affect Sm. fehlmanni. Historical and demographic hypotheses are raised to explain the different patterns of population structure and distribution between these species. Strategies

  3. Genetic diversity affects the strength of population regulation in a marine fish.

    PubMed

    Johnson, D W; Freiwald, J; Bernardi, G

    2016-03-01

    Variation is an essential feature of biological populations, yet much of ecological theory treats individuals as though they are identical. This simplifying assumption is often justified by the perception that variation among individuals does not have significant effects on the dynamics of whole populations. However, this perception may be skewed by a historic focus on studying single populations. A true evaluation of the extent to which among-individual variation affects the dynamics of populations requires the study of multiple populations. In this study, we examined variation in the dynamics of populations of a live-bearing, marine fish (black surfperch; Embiotoca jacksoni). In collaboration with an organization of citizen scientists (Reef Check California), we were able to examine the dynamics of eight populations that were distributed throughout approximately 700 km of coastline, a distance that encompasses much of this species' range. We hypothesized that genetic variation within a local population would be related to the intensity of competition and to the strength of population regulation. To test this hypothesis, we examined whether genetic diversity (measured by the diversity of mitochondrial DNA haplotypes) was related to the strength of population regulation. Low-diversity populations experienced strong density dependence in population growth rates and population sizes were regulated much more tightly than they were in high-diversity populations. Mechanisms that contributed to this pattern include links between genetic diversity, habitat use, and spatial crowding. On average, low-diversity populations used less of the available habitat and exhibited greater spatial clustering (and more intense competition) for a given level of density (measured at the scale of the reef). Although the populations we studied also varied with respect to exogenous characteristics (habitat complexity, densities of predators, and interspecific competitors), none of these

  4. Genetic diversity affects the strength of population regulation in a marine fish.

    PubMed

    Johnson, D W; Freiwald, J; Bernardi, G

    2016-03-01

    Variation is an essential feature of biological populations, yet much of ecological theory treats individuals as though they are identical. This simplifying assumption is often justified by the perception that variation among individuals does not have significant effects on the dynamics of whole populations. However, this perception may be skewed by a historic focus on studying single populations. A true evaluation of the extent to which among-individual variation affects the dynamics of populations requires the study of multiple populations. In this study, we examined variation in the dynamics of populations of a live-bearing, marine fish (black surfperch; Embiotoca jacksoni). In collaboration with an organization of citizen scientists (Reef Check California), we were able to examine the dynamics of eight populations that were distributed throughout approximately 700 km of coastline, a distance that encompasses much of this species' range. We hypothesized that genetic variation within a local population would be related to the intensity of competition and to the strength of population regulation. To test this hypothesis, we examined whether genetic diversity (measured by the diversity of mitochondrial DNA haplotypes) was related to the strength of population regulation. Low-diversity populations experienced strong density dependence in population growth rates and population sizes were regulated much more tightly than they were in high-diversity populations. Mechanisms that contributed to this pattern include links between genetic diversity, habitat use, and spatial crowding. On average, low-diversity populations used less of the available habitat and exhibited greater spatial clustering (and more intense competition) for a given level of density (measured at the scale of the reef). Although the populations we studied also varied with respect to exogenous characteristics (habitat complexity, densities of predators, and interspecific competitors), none of these

  5. Framework for Evaluating Habitat Restoration Success with Respect to Fish Habitat- and Population-related Beneficial Use Impairments

    EPA Science Inventory

    A major challenge of evaluating restoration progress is establishing a cause-effect relationship between observed changes in fish abundance and ongoing aquatic habitat restoration. Since 1979, fish populations within the St. Louis River Area of Concern, which were severely degrad...

  6. Predicting adult stature from metatarsal length in a Portuguese population.

    PubMed

    Cordeiro, Cristina; Muñoz-Barús, José I; Wasterlain, Sofia; Cunha, Eugénia; Vieira, Duarte N

    2009-12-15

    Stature can be considered one of the "big four" parameters to be ascertained within the biological profile in cases of forensic anthropology. However, the most reliable available methods for stature estimation require the preservation of the long bones, but since this is very often not the case, the development of alternative methods, based on distinct bones, is mandatory. Therefore, in the present work the reliability of the first two metatarsal bones in reconstructing stature is tested. The data consist of length measurements taken from the first two metatarsals removed from documented cadavers of known stature. The sample for this study consists of 220 metatarsals, namely 110 first metatarsals and 110 second metatarsals collected during the autopsies carried out in the National Institute of Legal Medicine in Portugal. The aim was to propose regression equations for the Portuguese population and test the formulae proposed by other authors to determine adult stature using metatarsal bones. We found that when estimating stature from measurement of the metatarsals, the best correlation was that obtained from the relationship with the maximum length of the 2nd metatarsal. The corresponding regression equation is as follows: S=790.041+11.689M2.

  7. Perceived stress and mortality in a Taiwanese older adult population.

    PubMed

    Vasunilashorn, Sarinnapha; Glei, Dana A; Weinstein, Maxine; Goldman, Noreen

    2013-11-01

    Perceived stress is associated with poor health outcomes including negative affect, increased susceptibility to the common cold and cardiovascular disease; the consequences of perceived stress for mortality, however, have received less attention. This study characterizes the relationship between perceived stress and 11-year mortality in a population of Taiwanese adults aged 53+ years. Using the Survey of Health and Living Status of the Near Elderly and Elderly of Taiwan, we calculated a composite measure of perceived stress based on six items pertaining to the health, financial situation, and occupation of the respondents and their families. Proportional hazard models were used to determine whether perceived stress predicted mortality. After adjusting for sociodemographic factors only, we found that a one standard deviation increase in perceived stress was associated with a 19% increase in all-cause mortality risk during the 11-year follow-up period (hazard ratio, HR = 1.19, 95% confidence interval, CI 1.13-1.26). The relationship was greatly attenuated when perceptions of stress regarding health were excluded, and was not significant after adjusting for medical conditions, mobility limitations and depressive symptoms. We conclude that the association between perceived stress and mortality is explained by an individual's current health; however, our data do not allow us to distinguish between two possible interpretations of this conclusion: (a) the relationship between perceived stress and mortality is spurious, or (b) poor health acts as the mediator.

  8. Expansion of Dreissena into offshore waters of Lake Michigan and potential impacts on fish populations

    USGS Publications Warehouse

    Bunnell, D.B.; Madenjian, C.P.; Holuszko, J.D.; Adams, J.V.; French, J. R. P.

    2009-01-01

    Lake Michigan was invaded by zebra mussels (Dreissena polymorpha) in the late 1980s and then followed by quagga mussels (D. bugensis) around 1997. Through 2000, both species (herein Dreissena) were largely restricted to depths less than 50??m. Herein, we provide results of an annual lake-wide bottom trawl survey in Lake Michigan that reveal the relative biomass and depth distribution of Dreissena between 1999 and 2007 (although biomass estimates from a bottom trawl are biased low). Lake-wide mean biomass density (g/m2) and mean depth of collection revealed no trend between 1999 and 2003 (mean = 0.7??g/m2 and 37??m, respectively). Between 2004 and 2007, however, mean lake-wide biomass density increased from 0.8??g/m2 to 7.0??g/m2, because of increased density at depths between 30 and 110??m, and mean depth of collection increased from 42 to 77??m. This pattern was confirmed by a generalized additive model. Coincident with the Dreissena expansion that occurred beginning in 2004, fish biomass density (generally planktivores) declined 71% between 2003 and 2007. Current understanding of fish population dynamics, however, indicates that Dreissena expansion is not the primary explanation for the decline of fish, and we provide a species-specific account for more likely underlying factors. Nonetheless, future sampling and research may reveal a better understanding of the potential negative interactions between Dreissena and fish in Lake Michigan and elsewhere.

  9. The Power to Detect Trends in Missouri River Fish Populations within the Pallid Sturgeon Population Assessment Program

    USGS Publications Warehouse

    Bryan, Janice L.; Wildhaber, Mark L.; Gladish, Dan; Holan, Scott; Ellerseick, Mark

    2010-01-01

    As with all large rivers in the United States, the Missouri River has been altered, with approximately 32.5 percent of the main stem length impounded and 32.5 percent channelized. These physical alterations to the environment have had effects on the fisheries, but studies examining the effects of alterations have been localized and for short periods of time. In response to the U.S. Fish and Wildlife Service biological opinion, the U.S. Army Corps of Engineers initiated monitoring of the fish community of the Missouri River in 2003. The goal of the Pallid Sturgeon Population Assessment Program is to provide information to detect changes in populations and habitat preferences with time for pallid sturgeon (Scaphirhynchus albus) and native target species in the Missouri River Basin. To determine statistical power of the Pallid Sturgeon Population Assessment Program, a power analysis was conducted using a normal linear mixed model with variance component estimates based on the first 3 years of data (2003 to 2005). In cases where 3 years of data were unavailable, estimates were obtained using those data. It was determined that at least 20 years of data, sampling 12 bends with 8 subsamples per bend, would be required to detect a 5 percent annual decline in most of the target fish populations. Power varied between Zones. Zone 1 (upstream from Lake Sakakawea) did not have any species/gear type combinations with adequate power, whereas Zone 3 (downstream from Gavins Point Dam) had 19 species/gear type combinations with adequate power. With a slight increase in the sampling effort to 12 subsamples per bend, the Pallid Sturgeon Population Assessment Program has adequate power to detect declines in shovelnose sturgeon (S. platorynchus) throughout the entire Missouri River because of large catch rates. The lowest level of non-occurrence (in other words, zero catches) at the bend level for pallid sturgeon was 0.58 using otter trawls in Zone 1. Consequently, the power of the

  10. Microgeographic population structure of green swordail fish: genetic differentiation despite abundant migration.

    PubMed

    Tatarenkov, A; Healey, C I M; Avise, J C

    2010-01-01

    Swordtails (Xiphophorus; Poeciliidae) have figured prominently in research on fish mating behaviours, sexual selection, and carcinogenesis, but their population structures and dispersal patterns have been relatively neglected. Using nine microsatellite loci, we estimated genetic differentiation in Xiphophorus helleri within and between adjacent streams in Belize. The genetic data were complemented by a tagging study of movement within one stream. In the absence of physical dispersal barriers (waterfalls), population structure followed an isolation by distance (IBD) pattern. Genetic differentiation (F(ST) up to 0.07) was significant between and within creeks, despite high dispersal in the latter as judged by the tagging data. Such heterogeneity apparently was a result of genetic drift in local demes, due to small population sizes and highly skewed paternity. The IBD pattern was interrupted by waterfalls, boosting F(ST) above 0.30 between adjacent samples across these barriers. Overall, our results are helpful in understanding the interplay of evolutionary forces and population dynamics in a small fish living in a changeable habitat. PMID:20015140

  11. Microgeographic population structure of green swordail fish: genetic differentiation despite abundant migration.

    PubMed

    Tatarenkov, A; Healey, C I M; Avise, J C

    2010-01-01

    Swordtails (Xiphophorus; Poeciliidae) have figured prominently in research on fish mating behaviours, sexual selection, and carcinogenesis, but their population structures and dispersal patterns have been relatively neglected. Using nine microsatellite loci, we estimated genetic differentiation in Xiphophorus helleri within and between adjacent streams in Belize. The genetic data were complemented by a tagging study of movement within one stream. In the absence of physical dispersal barriers (waterfalls), population structure followed an isolation by distance (IBD) pattern. Genetic differentiation (F(ST) up to 0.07) was significant between and within creeks, despite high dispersal in the latter as judged by the tagging data. Such heterogeneity apparently was a result of genetic drift in local demes, due to small population sizes and highly skewed paternity. The IBD pattern was interrupted by waterfalls, boosting F(ST) above 0.30 between adjacent samples across these barriers. Overall, our results are helpful in understanding the interplay of evolutionary forces and population dynamics in a small fish living in a changeable habitat.

  12. Comparing climate change and species invasions as drivers of coldwater fish population extirpations.

    PubMed

    Sharma, Sapna; Vander Zanden, M Jake; Magnuson, John J; Lyons, John

    2011-01-01

    Species are influenced by multiple environmental stressors acting simultaneously. Our objective was to compare the expected effects of climate change and invasion of non-indigenous rainbow smelt (Osmerus mordax) on cisco (Coregonus artedii) population extirpations at a regional level. We assembled a database of over 13,000 lakes in Wisconsin, USA, summarising fish occurrence, lake morphology, water chemistry, and climate. We used A1, A2, and B1 scenarios from the Intergovernmental Panel on Climate Change (IPCC) of future temperature conditions for 15 general circulation models in 2046-2065 and 2081-2100 totalling 78 projections. Logistic regression indicated that cisco tended to occur in cooler, larger, and deeper lakes. Depending upon the amount of warming, 25-70% of cisco populations are predicted to be extirpated by 2100. In addition, cisco are influenced by the invasion of rainbow smelt, which prey on young cisco. Projecting current estimates of rainbow smelt spread and impact into the future will result in the extirpation of about 1% of cisco populations by 2100 in Wisconsin. Overall, the effect of climate change is expected to overshadow that of species invasion as a driver of coldwater fish population extirpations. Our results highlight the potentially dominant role of climate change as a driver of biotic change.

  13. Reversal of parenteral nutrition-associated liver disease with a fish oil-based lipid emulsion (Omegaven) in an adult dependent on home parenteral nutrition.

    PubMed

    Burns, David L; Gill, Brian M

    2013-03-01

    Patients with intestinal failure and short bowel syndrome usually require chronic parenteral nutrition (PN). PN is associated with risks, including infections, vascular thrombosis, and liver disease. PN-associated liver disease (PNALD) can progress from steatosis to chronic hepatitis and ultimately to cirrhosis. The etiology of PNALD is not completely understood. Therapies for PNALD include carbohydrate or lipid calorie reduction, antibiotics, or the use of ursodeoxycholic acid. When these efforts fail, therapeutic options are limited and liver transplantation may be required. The transition from a soybean- to a fish oil-based lipid formulation, such as the ω-3 parenteral lipid formulation (Omegaven), has shown a dramatic reversal of PNALD within the pediatric population. This is the first report of a PN-dependent adult in the United States complicated by PNALD and hepatic failure who had improvement of liver disease with an ω-3 fish oil-based parenteral formulation.

  14. Crisis Model for Older Adults: Special Considerations for an Aging Population

    ERIC Educational Resources Information Center

    Jungers, Christin M.; Slagel, Leslie

    2009-01-01

    As the U.S. population ages, counselors must begin structuring their interactions to meet the unique needs of older adults, especially in the area of crisis intervention. The purposes of this article are to draw attention to the rapidly growing, often disregarded older population and to introduce the Crisis Model for Older Adults (CM-OA), an…

  15. POPULATION GENETIC STRUCTURE OF A NON-MIGRATORY MARINE FISH FUNDULUS HETERCLITUS ACROSS A STRONG GRADIENT OF PCB CONTAMINATION

    EPA Science Inventory

    Populations of the estuarine fish Fundulus heteroclitus indigenous to contaminated sites exhibit heritable resistance to some of the toxic effects of early life-stage exposure to polychlorinated biphenyls (PCBs). This evolved tolerance provides evidence of strong selection by PCB...

  16. [Study on preferred food of adult Mylabris phalerata in different geographical populations].

    PubMed

    Mo, Rang-yu; Sun, Nian-xi; Peng, Rui

    2014-11-01

    With the deterioration of environment, and the excessive collection of wild resources, the wild populations of Myla- bris phalerata Pallas are less and less, almost extincted in many traditional distribution areas. It is necessary to breed M. phalerata artificially for sustainable utilization. Food preference of adult M. phalerata is the key to its provenance screening and domestication in the artificial breeding. In this paper, the food preference of 3 geographical populations of M. phalerata was studied. The results showed that the food preferences of adult M. phalerata in different geographical populations were different. The adult M. phalerata in Wuming preferred cucumber flowers, gourd flowers and melon flowers. The adult M. phalerata in Tianlin preferred cowpea flowers. And the adult M. phalerata in Guangzhou preferred cowpea flowers and gourd flowers. Gourd flowers were the most attractive food for the adult M. phalerata of 3 geographical populations of M. phalerata. PMID:25850255

  17. Potential role of radial glia in adult neurogenesis of teleost fish.

    PubMed

    Zupanc, Günther K H; Clint, Sorcha C

    2003-07-01

    Persistence of radial glia within the adult central nervous system is a widespread phenomenon among fish. Based on a series of studies in the teleost species Apteronotus leptorhynchus, we propose that one function of this persistence is the involvement of radial glia in adult neurogenesis, i.e., the generation and further development of new neurons in the adult central nervous system. In particular, evidence has been obtained for the involvement of radial glia in the guidance of migrating young neurons in both the intact and the regenerating brain; for a possible role as precursor cells from which new neurons arise; and for its role as a source of trophic substances promoting the generation, differentiation, and/or survival of new neurons. These functions contribute not only to the potential of the intact brain to generate new neurons continuously, and of the injured brain to replace damaged cells by newly generated ones, but they also provide an essential part of the cellular substrate of behavioral plasticity.

  18. Fish oil supplementation of rats during pregnancy reduces adult disease risks in their offspring.

    PubMed

    Joshi, Sadhana; Rao, Shobha; Golwilkar, Ajit; Patwardhan, Manisha; Bhonde, Ramesh

    2003-10-01

    Metabolic programming in utero due to maternal undernutrition is considered to increase the risk of adult diseases in offspring. It is therefore of relevance to investigate how dietary supplementation of specific nutrients can ameliorate the negative effects of maternal malnutrition. We examined the effects of supplementing fish oil or folic acid, both of which are conventional supplements in maternal intervention, on risk factors in the offspring as adults. Pregnant female rats from 4 groups (n = 6/group) were fed casein diets with 18 g/100 g protein (control diet), 12 g/100 g protein supplemented with 8 mg folic acid/kg diet (0.08 mg/kg diet) (FAS), 12 g/100 g protein without folic acid (FAD) or 12 g/100 g protein supplemented with 7 g/100 g fish oil (FOIL). Pups were weaned to a standard laboratory diet with 18 g/100 g protein. Serum glucose, insulin and cholesterol and plasma homocysteine levels were measured in the offspring at 6 and 11 mo of age. Serum glucose in 11-mo-old male and female pups was greater (P < 0.05) in both the FAS (males 2.46 +/- 0.51, females 2.49 +/- 0.29 mmol/L) and FAD groups (2.48 +/- 0.28 and 2.67 +/- 0.41 mmol/L) than in controls (2.03 +/- 0.15 and 2.02 +/- 0.18 mmol/L). Serum insulin concentrations were higher (P < 0.05) in the FAD group (males 1476 +/- 317, females 1441 +/- 220 pmol/L) but were lower in males from the FAS group (483 +/- 165 pmol/L) compared with controls (males 917 +/- 373, females 981 +/- 264 pmol/L). Glucose and insulin concentrations did not differ between the control and FOIL groups. Plasma homocysteine levels were lower (P < 0.05) only in 11-mo-old folate-deficient males; none of the other groups differed from the controls. Maternal supplementation of fish oil to a diet containing marginal protein was beneficial in maintaining circulating glucose, insulin, cholesterol and homocysteine levels in the offspring as adults.

  19. Independent and interactive effects of plant sterols and fish oil n-3 long-chain polyunsaturated fatty acids on the plasma lipid profile of mildly hyperlipidaemic Indian adults.

    PubMed

    Khandelwal, Shweta; Demonty, Isabelle; Jeemon, Panniyammakal; Lakshmy, Ramakrishnan; Mukherjee, Rajat; Gupta, Ruby; Snehi, Uma; Niveditha, Devasenapathy; Singh, Yogendra; van der Knaap, Henk C M; Passi, Santosh J; Prabhakaran, Dorairaj; Reddy, K Srinath

    2009-09-01

    The present study was designed to evaluate the independent and interactive effects of a once-a-day yoghurt drink providing 2 g plant sterols/d and capsules providing 2 g fish oil n-3 long-chain (LC) PUFA/d on plasma lipids, apolipoproteins and LDL particle size. Following a 2-week run-in period, 200 mildly hypercholesterolaemic Indian adults aged 35-55 years were randomised into one of four groups of a 2 x 2 factorial, double-blind controlled trial. The 4-week treatments consisted of (1) control yoghurt drink and control capsules, (2) control yoghurt drink and fish oil capsules, (3) plant sterol-enriched yoghurt drink and control capsules, or (4) plant sterol-enriched yoghurt drink and fish oil capsules. Blood was drawn before and after the 4-week intervention. Changes in health status, lifestyle and dietary habits, and daily compliance were recorded. The main effects of plant sterols were a 4.5 % reduction in LDL-cholesterol and a 15 % reduction in TAG without a significant change in HDL-cholesterol. Overall, fish oil n-3 LC-PUFA did not significantly affect cholesterol concentrations but reduced TAG by 15 % and increased HDL-cholesterol by 5.4 %. The combination significantly lowered TAG by 15 % v. control. No significant interaction between plant sterols and n-3 LC-PUFA was observed on plasma cholesterol concentrations. In conclusion, once-a-day intake of 2 g plant sterols/d in a yoghurt drink, 2 g fish oil n-3 LC-PUFA/d in capsules, and their combination had beneficial effects on the lipid profile of mildly hypercholesterolaemic Indian adults. The potent hypotriacylglycerolaemic effect of plant sterols observed in the present study and this population warrants additional investigation. PMID:19296875

  20. Intersex in fishes and amphibians: population implications, prevalence, mechanisms and molecular biomarkers.

    PubMed

    Abdel-Moneim, Ahmed; Coulter, David P; Mahapatra, Cecon T; Sepúlveda, Maria S

    2015-11-01

    Intersex is defined as the abnormal presence of both testicular and ovarian cells in gonads of gonochoristic animals. Its occurrence is widespread and reports on its presence in the gonads of vertebrates continues to increase. In this review, we use standardized terminology to summarize the current knowledge of intersex in gonochoristic fishes and amphibians. We describe the different indices that have been used to assess the severity of intersex and synthesize reports discussing the prevalence of intersex in relation to different types of pollutants. In addition, we evaluate the geographic distribution and chronology of the reported cases of intersex in fishes and amphibians, their pathological descriptions and severity and discuss species sensitivities. We also summarize molecular biomarkers that have been tested for early detection of intersex in wild populations and highlight additional biomarkers that target molecular pathways involved in gonadal development that require further investigation for use in the diagnosis of intersex. Finally, we discuss the needs for future research in this field.

  1. Omics and Environmental Science Genomic Approaches With Natural Fish Populations From Polluted Environments

    PubMed Central

    Bozinovic, Goran; Oleksiak, Marjorie F.

    2010-01-01

    Transcriptomics and population genomics are two complementary genomic approaches that can be used to gain insight into pollutant effects in natural populations. Transcriptomics identify altered gene expression pathways while population genomics approaches more directly target the causative genomic polymorphisms. Neither approach is restricted to a pre-determined set of genes or loci. Instead, both approaches allow a broad overview of genomic processes. Transcriptomics and population genomic approaches have been used to explore genomic responses in populations of fish from polluted environments and have identified sets of candidate genes and loci that appear biologically important in response to pollution. Often differences in gene expression or loci between polluted and reference populations are not conserved among polluted populations suggesting a biological complexity that we do not yet fully understand. As genomic approaches become less expensive with the advent of new sequencing and genotyping technologies, they will be more widely used in complimentary studies. However, while these genomic approaches are immensely powerful for identifying candidate gene and loci, the challenge of determining biological mechanisms that link genotypes and phenotypes remains. PMID:21072843

  2. Misperception of self-reported adherence to the fruit, vegetable and fish guidelines in older Dutch adults.

    PubMed

    Dijkstra, S C; Neter, J E; Brouwer, I A; Huisman, M; Visser, M

    2014-11-01

    In this study we investigated (the degree of) misperception of adherence to the fruit, vegetable and fish guidelines in older Dutch adults and examined to what extent misperception is associated with socio-economic position (SEP) and other demographic, lifestyle and nutrition-related characteristics. The sample included 1057 community dwelling adults, aged 55-85 years, who participated in the Longitudinal Aging Study Amsterdam. Respondents completed a lifestyle questionnaire which included a food frequency questionnaire to calculate fruit, vegetable and fish intake. After current dietary guidelines were explained, respondents were asked to indicate whether they believed they adhered to the fruit, vegetable and fish guidelines. Characteristics potentially associated with misperception included level of income and education, lifestyle factors, nutritional knowledge, as well as attitude, social support and self-efficacy toward healthy eating. In the total sample, 69.1% of the older adults reported to adhere to the fruit guideline, 77.5% to the vegetable guideline, and 36.4% to the fish guideline. Based on the calculated intake data, 82.6% adhered to the fruit guideline, 65.5% to the vegetable guideline and 33.8% to the fish guideline. Overestimation of adherence was most common for the vegetable guideline (18.7%). Multivariate analysis, adjusted for level of income as well as for attitude and self-efficacy toward healthy eating, showed that lower educated respondents were more likely to overestimate their adherence to the vegetable guideline (relative index of inequality (RII): 2.97 (95% CI: 1.47-6.01)). Overestimation rates for fish (3.4%) and fruit (2.3%) were lower and not associated with any of the characteristics. This study showed that overestimation in older adults was common for adherence to the vegetable guideline and especially in those with a lower education level, but not for adherence to the fruit and fish guideline.

  3. Discrimination of Astyanax altiparanae (Characiformes, Characidae) populations by applying Fourier transform-infrared photoacoustic spectroscopy in the fish scales

    NASA Astrophysics Data System (ADS)

    de Almeida, F. S.; Santana, C. A.; Lima, D. M. V.; Andrade, L. H. C.; Súarez, Y. R.; Lima, S. M.

    2016-05-01

    Astyanax altiparanae fish species is considered very generalist and opportunist, occupying different types and sizes of environments. This characteristic turns it very appropriate as bioindicator or biomarked. Therefore, in this work, A. altiparanae fish species was used to identify populations by using the Fourier transform infrared spectroscopy directly in its scales. The discriminant analysis applied in the infrared spectra demonstrated a significant differentiation among the analyzed populations, with the first and second canonical roots explain together 100% of the data variation. The obtained results were correlated with environmental descriptors and diet of fishes, and a better agreement was obtained when spectroscopic data were compared with the composition of food present in the fish stomachs. However, this study indicates that the combination of infrared absorption spectroscopy with discriminant analysis is a very appropriate methodology to be used in fish scales as bioindicator for intraspecific study.

  4. Prevalence of Common Ocular Morbidities in Adult Population of Aligarh

    PubMed Central

    Haq, Inaamul; Khan, Zulfia; Khalique, Najam; Amir, Ali; Jilani, Fatima A; Zaidi, Meena

    2009-01-01

    Aims and Objectives: To determine the prevalence of common ocular morbidities (cataract, refractive errors, glaucoma, and corneal opacities) and their demographic and sociocultural correlates. Settings and Design: The present cross-sectional study was conducted in the field practice areas of the Department of Community Medicine, JNMC, AMU, Aligarh, for a period of one year, from September 2005 to August 2006. Materials and Methods: Systematic random sampling was done to select the required sample size. All adults aged 20 years and above in the selected households were interviewed and screened using a 6/9 illiterate ‘E’ chart. Those who could not read the ‘E’ chart were referred to the respective health training center for a complete eye examination by an ophthalmologist. Statistical Analysis: Chi- square test. Results: The prevalence of visual impairment, low vision, and blindness, based on presenting visual acuity was 13.0, 7.8, and 5.3%, respectively. The prevalence of cataract was 21.7%. Bilateral cataract was present in 16.9% of the population. Cataract was significantly associated with age, education, and fuel use. The prevalence of myopia, hypermetropia, and astigmatism was 11.5, 9.8, and 3.7%, respectively. Glaucoma was diagnosed in six patients, giving a prevalence rate of 0.9%. All the six patients of glaucoma were aged above 40 years. The prevalence of corneal opacity was 4.2%. Conclusion: There is a high prevalence of treatable or preventable morbidities such as cataract, refractive errors, and corneal opacity. PMID:20049295

  5. Estimate of intake of sulfites in the Belgian adult population.

    PubMed

    Vandevijvere, S; Temme, E; Andjelkovic, M; De Wil, M; Vinkx, C; Goeyens, L; Van Loco, J

    2010-08-01

    An exposure assessment was performed to estimate the usual daily intake of sulfites in the Belgian adult population. Food consumption data were retrieved from the national food consumption survey. In a first step, individual food consumption data were multiplied with the maximum permitted use levels for sulfites, expressed as sulphur dioxide, per food group (Tier 2). In a second step, on the basis of a literature review of the occurrence of sulfites in different foods, the results of the Tier 2 exposure assessment and available occurrence data from the control programme of the competent authority, a refined list of foods was drafted for the quantification of sulphite. Quantification of sulphite was performed by a high-performance ion chromatography method with eluent conductivity detector in beers and potato products. Individual food consumption data were then multiplied with the actual average concentrations of sulfite per food group, or the maximum permitted levels in case actual levels were not available (partial Tier 3). Usual intakes were calculated using the Nusser method. The mean intake of sulfites was 0.34 mg kg(-1) bw day(-1) (Tier 2), corresponding to 49% of the acceptable daily intake (ADI) and 0.19 mg kg(-1) bw day(-1), corresponding to 27% of the ADI (partial Tier 3). The food group contributing most to the intake of sulfites was wines. The results showed that the intake of sulfites is likely to be below the ADI in Belgium. However, there are indications that high consumers of wine have an intake around the ADI.

  6. Indirect Effects of Impoundment on Migrating Fish: Temperature Gradients in Fish Ladders Slow Dam Passage by Adult Chinook Salmon and Steelhead

    PubMed Central

    Caudill, Christopher C.; Keefer, Matthew L.; Clabough, Tami S.; Naughton, George P.; Burke, Brian J.; Peery, Christopher A.

    2013-01-01

    Thermal layering in reservoirs upstream from hydroelectric dams can create temperature gradients in fishways used by upstream migrating adults. In the Snake River, Washington, federally-protected adult salmonids (Oncorhynchus spp.) often encounter relatively cool water in dam tailraces and lower ladder sections and warmer water in the upstream portions of ladders. Using radiotelemetry, we examined relationships between fish passage behavior and the temperature difference between the top and bottom of ladders (∆T) at four dams over four years. Some spring Chinook salmon (O. tshawytscha) experienced ∆T ≥ 0.5 °C. Many summer and fall Chinook salmon and summer steelhead (O. mykiss) experienced ∆T ≥ 1.0 °C, and some individuals encountered ΔT > 4.0°C. As ΔT increased, migrants were consistently more likely to move down fish ladders and exit into dam tailraces, resulting in upstream passage delays that ranged from hours to days. Fish body temperatures equilibrated to ladder temperatures and often exceeded 20°C, indicating potential negative physiological and fitness effects. Collectively, the results suggest that gradients in fishway water temperatures present a migration obstacle to many anadromous migrants. Unfavorable temperature gradients may be common at reservoir-fed fish passage facilities, especially those with seasonal thermal layering or stratification. Understanding and managing thermal heterogeneity at such sites may be important for ensuring efficient upstream passage and minimizing stress for migratory, temperature-sensitive species. PMID:24392020

  7. Indirect effects of impoundment on migrating fish: temperature gradients in fish ladders slow dam passage by adult Chinook salmon and steelhead.

    PubMed

    Caudill, Christopher C; Keefer, Matthew L; Clabough, Tami S; Naughton, George P; Burke, Brian J; Peery, Christopher A

    2013-01-01

    Thermal layering in reservoirs upstream from hydroelectric dams can create temperature gradients in fishways used by upstream migrating adults. In the Snake River, Washington, federally-protected adult salmonids (Oncorhynchus spp.) often encounter relatively cool water in dam tailraces and lower ladder sections and warmer water in the upstream portions of ladders. Using radiotelemetry, we examined relationships between fish passage behavior and the temperature difference between the top and bottom of ladders (∆T) at four dams over four years. Some spring Chinook salmon (O. tshawytscha) experienced ∆T ≥ 0.5 °C. Many summer and fall Chinook salmon and summer steelhead (O. mykiss) experienced ∆T ≥ 1.0 °C, and some individuals encountered ΔT > 4.0°C. As ΔT increased, migrants were consistently more likely to move down fish ladders and exit into dam tailraces, resulting in upstream passage delays that ranged from hours to days. Fish body temperatures equilibrated to ladder temperatures and often exceeded 20°C, indicating potential negative physiological and fitness effects. Collectively, the results suggest that gradients in fishway water temperatures present a migration obstacle to many anadromous migrants. Unfavorable temperature gradients may be common at reservoir-fed fish passage facilities, especially those with seasonal thermal layering or stratification. Understanding and managing thermal heterogeneity at such sites may be important for ensuring efficient upstream passage and minimizing stress for migratory, temperature-sensitive species. PMID:24392020

  8. Indirect effects of impoundment on migrating fish: temperature gradients in fish ladders slow dam passage by adult Chinook salmon and steelhead.

    PubMed

    Caudill, Christopher C; Keefer, Matthew L; Clabough, Tami S; Naughton, George P; Burke, Brian J; Peery, Christopher A

    2013-01-01

    Thermal layering in reservoirs upstream from hydroelectric dams can create temperature gradients in fishways used by upstream migrating adults. In the Snake River, Washington, federally-protected adult salmonids (Oncorhynchus spp.) often encounter relatively cool water in dam tailraces and lower ladder sections and warmer water in the upstream portions of ladders. Using radiotelemetry, we examined relationships between fish passage behavior and the temperature difference between the top and bottom of ladders (∆T) at four dams over four years. Some spring Chinook salmon (O. tshawytscha) experienced ∆T ≥ 0.5 °C. Many summer and fall Chinook salmon and summer steelhead (O. mykiss) experienced ∆T ≥ 1.0 °C, and some individuals encountered ΔT > 4.0°C. As ΔT increased, migrants were consistently more likely to move down fish ladders and exit into dam tailraces, resulting in upstream passage delays that ranged from hours to days. Fish body temperatures equilibrated to ladder temperatures and often exceeded 20°C, indicating potential negative physiological and fitness effects. Collectively, the results suggest that gradients in fishway water temperatures present a migration obstacle to many anadromous migrants. Unfavorable temperature gradients may be common at reservoir-fed fish passage facilities, especially those with seasonal thermal layering or stratification. Understanding and managing thermal heterogeneity at such sites may be important for ensuring efficient upstream passage and minimizing stress for migratory, temperature-sensitive species.

  9. Dietary patterns and food choices of a population sample of adults on Guam.

    PubMed

    Pobocik, Rebecca S; Trager, Alison; Monson, Lora Morrell

    2008-01-01

    This study examined dietary patterns of adults on Guam. Four hundred subjects were selected via a multistage procedure to represent the island's population. A 24-hour dietary recall was administered via telephone in 1995 to 1996. Diets were computer analyzed. There were 4,913 food items reported, representing 1,042 individual foods. Most respondents, 51.3%, had a "more-frequent" eating pattern, 36.9% had "regular" and 11.8% had "less-frequent." Energy consumption increased (p<0.05) with eating frequency. Highest levels of all nutrients (p<0.05) were at the evening meal. The sexes did not differ in nutrient proportions by meal. Grains, meats, and beverages were eaten most frequently. Meat/fish, mixed dishes, and grains supplied 68% of the energy and 47% to 91% of the micronutrients. Twenty five percent of the carbohydrate was from sweetened drinks and desserts. Rice was the most frequently consumed food. More than half of the subjects had no fruit, a third had no vegetables, and only 38.5% had dairy foods. Calcium came from multiple sources: dairy (27.6%), mixed dishes (23.8%), fish (12.6%), desserts (8.5%) and vegetables (6.6%). Most people, 91.8%, had fiesta meals with median consumption at 6 meals per year (range: 0 to 200). Betel nut was used by 12.3% of the sample with median consumption 0 whole nuts per day (range: 0 to 25). Ethnic differences (p<0.01) were observed in both fiesta meal and betel nut consumption. The Guamanian diet includes limited use of traditional foods and dietary patterns associated with increased risk for chronic disease.

  10. Cenotes (sinkholes) of the Yucatan Peninsula, Mexico, as a habitat of adult trematodes of fish.

    PubMed

    Scholz, T; Vargas-Vázquez, J; Moravec, F; Vivas-Rodríguez, C; Mendoza-Franco, E

    1995-01-01

    Examination of a total of 581 fish specimens of 15 species from 39 cenotes (sinkholes) in the Yucatan Peninsula, southeastern Mexico, revealed the presence of 10 species of adult trematodes. These were as follows: Saccocoelioides sogandaresi Lumsden, 1963, Saccocoelioides sp. (family Haploporidae), Cichlasotrema ujati Pineda et Andrade, 1989 (Angiodictyidae), Crassicutis cichlasomae Manter, 1936 (Homalometridae), Magnivitellinum simplex Kloss, 1966 (Macroderoididae), Stunkardiella minima (Stunkard, 1938) (Acanthostomidae), Oligogonotylus manteri Watson, 1976 (Cryptogonimidae), Genarchella tropica (Manter, 1936), G. astyanactis (Watson, 1976), and G. isabellae (Lamothe-Argumedo, 1977) (Derogenidae). Saccocoelioides sogandaresi is reported from Mexico for the first time. Poecilia velifera and P. latipunctata for S. sogandaresi, Cichlasoma octofasciatum for C. cichlasomae, Cichlasoma friedrichstahli and C. meeki for O. manteri, and C. meeki, C. octofasciatum and Gobiomorus dormitor for G. isabellae represent new host records. Most species found are described and figured and their host range and distribution are discussed.

  11. Pigment patterns in adult fish result from superimposition of two largely independent pigmentation mechanisms.

    PubMed

    Ceinos, Rosa M; Guillot, Raúl; Kelsh, Robert N; Cerdá-Reverter, José M; Rotllant, Josep

    2015-03-01

    Dorso-ventral pigment pattern differences are the most widespread pigmentary adaptations in vertebrates. In mammals, this pattern is controlled by regulating melanin chemistry in melanocytes using a protein, agouti-signalling peptide (ASIP). In fish, studies of pigment patterning have focused on stripe formation, identifying a core striping mechanism dependent upon interactions between different pigment cell types. In contrast, mechanisms driving the dorso-ventral countershading pattern have been overlooked. Here, we demonstrate that, in fact, zebrafish utilize two distinct adult pigment patterning mechanisms - an ancient dorso-ventral patterning mechanism, and a more recent striping mechanism based on cell-cell interactions; remarkably, the dorso-ventral patterning mechanism also utilizes ASIP. These two mechanisms function largely independently, with resultant patterns superimposed to give the full pattern.

  12. Native fishes in the Truckee River: Are in-stream structures and patterns of population genetic structure related?

    PubMed

    Peacock, Mary M; Gustin, Mae S; Kirchoff, Veronica S; Robinson, Morgan L; Hekkala, Evon; Pizzarro-Barraza, Claudia; Loux, Tim

    2016-09-01

    In-stream structures are recognized as significant impediments to movement for freshwater fishes. Apex predators such as salmonids have been the focus of much research on the impacts of such barriers to population dynamics and population viability however much less research has focused on native fishes, where in-stream structures may have a greater impact on long term population viability of these smaller, less mobile species. Patterns of genetic structure on a riverscape can provide information on which structures represent real barriers to movement for fish species and under what specific flow conditions. Here we characterize the impact of 41 dam and diversion structures on movement dynamics under varying flow conditions for a suite of six native fishes found in the Truckee River of California and Nevada. Microsatellite loci were used to estimate total allelic diversity, effective population size and assess genetic population structure. Although there is spatial overlap among species within the river there are clear differences in species distributions within the watershed. Observed population genetic structure was associated with in-stream structures, but only under low flow conditions. High total discharge in 2006 allowed fish to move over potential barriers resulting in no observed population genetic structure for any species in 2007. The efficacy of in-stream structures to impede movement and isolate fish emerged only after multiple years of low flow conditions. Our results suggest that restricted movement of fish species, as a result of in-stream barriers, can be mitigated by flow management. However, as flow dynamics are likely to be altered under global climate change, fragmentation due to barriers could isolate stream fishes into small subpopulations susceptible to both demographic losses and losses of genetic variation.

  13. Can remote high-resolution mapping help individual-based fish population models go up-scale? (Invited)

    NASA Astrophysics Data System (ADS)

    Harvey, B.; Railsback, S.

    2009-12-01

    Spatially explicit, individual-based models of fish populations show great promise for linking physical conditions and processes to population dynamics. The ability to link physical processes and population outcomes is critical for optimizing habitat restoration efforts, forecasting the consequences of climate change, evaluating flow regimes, and other activities necessary to sustain at-risk fish populations. Because individual-based models simulate habitat from the perspective of individual fish, they commonly capture variation in physical habitat on a scale of 1- 50 square meters and rely on simulations (including hydraulic modeling) at the reach scale (0.2 to 1 km). Simulated reaches can be linked in some models such that virtual fish can move among them. The significance of the size, location and arrangement of reaches included in IBM simulations of fish populations has not been investigated in detail. However, the process of reach selection clearly benefits from information on channel physical conditions at the network scale, so that reaches can be selected to well-represent the diversity of habitat at larger spatial scales. High-resolution mapping of channel topography would be a richer source of network-scale information than others used to date, such as habitat typing and simple video. Remote, high-resolution mapping data might also provide a major step forward in the capability of individual-based models to address fish population dynamics at the network scale if the mapping data could be directly used for hydraulic simulations. Challenges for this step include the need to estimate physical habitat variables included in individual-based models that may not be readily discernable from topographic data, such as the availability of cover for fish. Exploring the use of high-resolution mapping data in individual-based modeling of fish populations seems worth doing, in that the individual-based models should be a particularly effective way to derive biological

  14. Native fishes in the Truckee River: Are in-stream structures and patterns of population genetic structure related?

    PubMed

    Peacock, Mary M; Gustin, Mae S; Kirchoff, Veronica S; Robinson, Morgan L; Hekkala, Evon; Pizzarro-Barraza, Claudia; Loux, Tim

    2016-09-01

    In-stream structures are recognized as significant impediments to movement for freshwater fishes. Apex predators such as salmonids have been the focus of much research on the impacts of such barriers to population dynamics and population viability however much less research has focused on native fishes, where in-stream structures may have a greater impact on long term population viability of these smaller, less mobile species. Patterns of genetic structure on a riverscape can provide information on which structures represent real barriers to movement for fish species and under what specific flow conditions. Here we characterize the impact of 41 dam and diversion structures on movement dynamics under varying flow conditions for a suite of six native fishes found in the Truckee River of California and Nevada. Microsatellite loci were used to estimate total allelic diversity, effective population size and assess genetic population structure. Although there is spatial overlap among species within the river there are clear differences in species distributions within the watershed. Observed population genetic structure was associated with in-stream structures, but only under low flow conditions. High total discharge in 2006 allowed fish to move over potential barriers resulting in no observed population genetic structure for any species in 2007. The efficacy of in-stream structures to impede movement and isolate fish emerged only after multiple years of low flow conditions. Our results suggest that restricted movement of fish species, as a result of in-stream barriers, can be mitigated by flow management. However, as flow dynamics are likely to be altered under global climate change, fragmentation due to barriers could isolate stream fishes into small subpopulations susceptible to both demographic losses and losses of genetic variation. PMID:27135585

  15. Evidence and population consequences of shared larval dispersal histories in a marine fish.

    PubMed

    Shima, Jeffrey S; Swearer, Stephen E

    2016-01-01

    Larval dispersal is disproportionately important for marine population ecolgy and evolution, yet our inability to track individuals severely constrains our understanding of this key process. We analyze otoliths of a small reef fish, the common triplefin (Forsterygion lapillum), to reconstruct individual dispersal histories and address the following questions: (1) How many discrete sets of dispersal histories (dispersal cohorts) contribute to replenishment of focal populations; (2) When do dispersal cohorts converge (a metric of shared dispersal histories among cohorts); and (3) Do these patterns predict spatiotemporal variation in larval supply? We used light traps to quantify larval supply, and otolith microstructure and microchemistry (using laser ablation inductively coupled plasma mass spectrometry; LA-ICP-MS) to reconstruct daily environmental histories of individuals in their 30-d lead-up to settlement. Our results indicate that a variable number of dispersal cohorts replenish focal populations (range of 2-8, mean of 4.3, standard deviation of 2.8). Convergence times varied (from 0 to > 30 d prior to settlement), and larval supply was negatively correlated with cohort evenness but not with the number of cohorts, or when they converged, indicating disproportionately large contributions from some cohorts (i.e., sweepstakes events). Collectively, our results suggest that larval reef fishes may variably disperse in shoals, to drive local replenishment and connectivity within a metapopulation.

  16. Population structure among octocoral adults and recruits identifies scale dependent patterns of population isolation in The Bahamas.

    PubMed

    Lasker, Howard R; Porto-Hannes, Isabel

    2015-01-01

    Patterns of dispersal and connectivity of the Caribbean gorgonian Antillogorgia elisabethae in The Bahamas were assessed in both adults and recently settled recruits from 13 sites using microsatellite loci. Adult populations along the Little Bahama Bank (LBB) exhibited a clear pattern of isolation by distance (IBD) which described 86% of the variance in pairwise genetic distances. Estimates of dispersal based on the IBD model suggested dispersal distances along the LBB on the order of 100 m. Increasing the spatial scale to include sites separated by open ocean generated an apparent IBD signal but the relationship had a greater slope and explained less of the variance. This relationship with distance reflected both stepping stone based IBD and regional differentiation probably created by ocean currents and barriers to dispersal that are correlated with geographic distance. Analysis of recruits from 4 sites on the LBB from up to 6 years did not detect differences between years nor differences with adult populations. The result suggests that neither selection on recruits nor inter-annual variation in dispersal affected adult population structure. Assignment tests of recruits indicated the most likely sources of the recruits were the local or adjacent populations. Most of the patterning in population structure in the northern Bahamas can be explained by geographic distance and oceanographic connectivity. Recognition of these complex patterns is important in developing management plans for A. elisabethae and in understanding the effects of disturbance to adult populations of A. elisabethae and similar species with limited dispersal. PMID:26157606

  17. Population structure among octocoral adults and recruits identifies scale dependent patterns of population isolation in The Bahamas

    PubMed Central

    Porto-Hannes, Isabel

    2015-01-01

    Patterns of dispersal and connectivity of the Caribbean gorgonian Antillogorgia elisabethae in The Bahamas were assessed in both adults and recently settled recruits from 13 sites using microsatellite loci. Adult populations along the Little Bahama Bank (LBB) exhibited a clear pattern of isolation by distance (IBD) which described 86% of the variance in pairwise genetic distances. Estimates of dispersal based on the IBD model suggested dispersal distances along the LBB on the order of 100 m. Increasing the spatial scale to include sites separated by open ocean generated an apparent IBD signal but the relationship had a greater slope and explained less of the variance. This relationship with distance reflected both stepping stone based IBD and regional differentiation probably created by ocean currents and barriers to dispersal that are correlated with geographic distance. Analysis of recruits from 4 sites on the LBB from up to 6 years did not detect differences between years nor differences with adult populations. The result suggests that neither selection on recruits nor inter-annual variation in dispersal affected adult population structure. Assignment tests of recruits indicated the most likely sources of the recruits were the local or adjacent populations. Most of the patterning in population structure in the northern Bahamas can be explained by geographic distance and oceanographic connectivity. Recognition of these complex patterns is important in developing management plans for A. elisabethae and in understanding the effects of disturbance to adult populations of A. elisabethae and similar species with limited dispersal. PMID:26157606

  18. Diet dynamics of the adult piscivorous fish community in Spirit Lake, Iowa, USA 1995-1997

    USGS Publications Warehouse

    Liao, H.; Pierce, C.L.; Larscheid, J.G.

    2002-01-01

    Diets of adults of six important piscivorous fish species, black crappie Pomoxis nigromaculatus, largemouth bass Micropterus salmoides, northern pike Esox lucius, smallmouth bass Micropterus dolomieui, walleye Stizostedion vitreum, and yellow perch Perca flavescens were quantified in Spirit Lake, Iowa, USA from May to October in 1995-1997. Forty-one prey taxa were found in the diets of these species, including 19 species of fish. The most important prey taxa overall were yellow perch, amphipods and dipterans. Diets of northern pike and walleye were dominated by yellow perch. Largemouth bass diets included large percentages of both yellow perch and black bullhead Ameiurus melas. Smallmouth bass diets included large percentages of both yellow perch and crayfish. Black crappie and yellow perch diets were dominated by invertebrates, primarily amphipods and dipterans. There were pronounced differences in diets among species, among size classes within species and over time. Most of the dominant prey taxa we documented in the diets of piscivorous species were in accordance with previous studies, but a few deviated significantly from expectations. Many of the temporal diet changes were asynchronous among piscivorous species and size classes, suggesting different responses to common prey resources over time.

  19. Female fecundity traits in wild populations of African annual fish: the role of the aridity gradient.

    PubMed

    Vrtílek, Milan; Reichard, Martin

    2016-08-01

    The evolution of life history is shaped by life expectancy. Life-history traits coevolve, and optimal states for particular traits are constrained by trade-offs with other life-history traits. Life histories contrast among species, but may also diverge intraspecifically, at the level of populations. We studied the evolution of female reproductive allocation strategy, using natural populations of two sympatric species of African annual fishes, Nothobranchius furzeri and Nothobranchius orthonotus. These species inhabit pools in the Mozambican savanna that are formed in the rainy season and persist for only 2-10 months. Using 207 female N. furzeri from 11 populations and 243 female N. orthonotus from 14 populations, we tested the effects of genetic background (intraspecific lineage) and life expectancy (position on the aridity gradient determining maximum duration of their temporary habitat) on female fecundity traits. First, we found that variation in female body mass was small within populations, but varied considerably among populations. Second, we found that fecundity was largely defined by female body mass and that females spawned most of their eggs in the morning. Third, we found that the trade-off between egg size and egg number varied among lineages of N. furzeri and this outcome has been confirmed by data from two separate years. Overall, we demonstrate that local conditions were important determinants for Nothobranchius growth and fecundity and that eggs size in arid region was less limited by female fecundity than in humid region. PMID:27547365

  20. Demographic Demise: The Declining Young Adult Population in New England

    ERIC Educational Resources Information Center

    Gittell, Ross

    2007-01-01

    Young adult workers provide businesses with the dynamic labor force and fresh ideas they need to innovate and grow. With their contributions to cultural, intellectual and social life, young adults also make New England a vibrant and interesting place to live. Young families support local schools and demand a strong educational system. Yet New…

  1. Does mobility explain variation in colonisation and population recovery among stream fishes?

    USGS Publications Warehouse

    Angermeier, Paul L.; Albanese, Brett; Peterson, James T.

    2009-01-01

    1. Colonisation and population recovery are crucial to species persistence in environmentally variable ecosystems, but are poorly understood processes. After documenting movement rates for several species of stream fish, we predicted that this variable would influence colonisation rates more strongly than local abundance, per cent occupancy, body size and taxonomic family. We also predicted that populations of species with higher movement rates would recover more rapidly than species with lower movement rates and that assemblage structure would change accordingly. 2. To test these predictions, we removed fishes from a headwater and a mainstem creek in southwest Virginia and monitored colonisation over a 2-year period. Using an information–theoretic approach, we evaluated the relative plausibility of 15 alternative models containing different combinations of our predictor variables. Our best-supported model contained movement rate and abundance and was 41 times more likely to account for observed patterns in colonisation rates than the next-best model. Movement rate and abundance were both positively related to colonisation rates and explained 88% of the variation in colonisation rates among species. 3. Population recovery, measured as the per cent of initial abundance restored, was also positively associated with movement rate. One species recovered within 3 months, most recovered within 2 years, but two species still had not recovered after 2 years. Despite high variation in recovery, the removal had only a slight impact on assemblage structure because species that were abundant in pre-removal samples were also abundant in post-removal samples. 4. The significance of interspecific variation in colonisation and recovery rates has been underappreciated because of the widely documented recovery of stream fish assemblages following fish kills and small-scale experimental defaunations. Our results indicate that recovery of the overall assemblage does not imply

  2. Visual Basic, Excel-based fish population modeling tool—The pallid sturgeon example

    USGS Publications Warehouse

    Moran, Edward H.; Wildhaber, Mark L.; Green, Nicholas S.; Albers, Janice L.

    2016-02-10

    The model presented in this report is a spreadsheet-based model using Visual Basic for Applications within Microsoft Excel (http://dx.doi.org/10.5066/F7057D0Z) prepared in cooperation with the U.S. Army Corps of Engineers and U.S. Fish and Wildlife Service. It uses the same model structure and, initially, parameters as used by Wildhaber and others (2015) for pallid sturgeon. The difference between the model structure used for this report and that used by Wildhaber and others (2015) is that variance is not partitioned. For the model of this report, all variance is applied at the iteration and time-step levels of the model. Wildhaber and others (2015) partition variance into parameter variance (uncertainty about the value of a parameter itself) applied at the iteration level and temporal variance (uncertainty caused by random environmental fluctuations with time) applied at the time-step level. They included implicit individual variance (uncertainty caused by differences between individuals) within the time-step level.The interface developed for the model of this report is designed to allow the user the flexibility to change population model structure and parameter values and uncertainty separately for every component of the model. This flexibility makes the modeling tool potentially applicable to any fish species; however, the flexibility inherent in this modeling tool makes it possible for the user to obtain spurious outputs. The value and reliability of the model outputs are only as good as the model inputs. Using this modeling tool with improper or inaccurate parameter values, or for species for which the structure of the model is inappropriate, could lead to untenable management decisions. By facilitating fish population modeling, this modeling tool allows the user to evaluate a range of management options and implications. The goal of this modeling tool is to be a user-friendly modeling tool for developing fish population models useful to natural resource

  3. Effects of stocking hatchery fish on the phenotype of indigenous populations in the amago salmon Oncorhynchus masou ishikawae in Japan.

    PubMed

    Kawamura, K; Furukawa, M; Kubota, M; Harada, Y

    2012-07-01

    The expression of colour marks (parr marks, red and black spots) of the amago salmon Oncorhynchus masou ishikawae was compared with microsatellite information, to see the effects of stocking hatchery fish on the phenotype of indigenous populations, which face extinction through extensive stocking. A Bayesian-based assignment test suggested introgression of two exotic clusters into one indigenous cluster in the stocked area and its vicinity. The number of parr marks was significantly higher in one hatchery-origin population, which exclusively comprised one exotic cluster. An increased number of red spots in stocked hatchery fish was probably a consequence of hatchery feeding conditions. The number of black spots was correlated with body size in many populations, except for hatchery and heavily introgressed populations. Coefficients of correlation and regression of black spots with body size, which were largest in indigenous populations, decreased with an increase of introgression by hatchery fish. As indigenous populations have low genetic diversity with high relatedness, it was inferred that the height of correlation and regression coefficients in black spots is caused by high genetic homogeneity and fixation of alleles in loci related to the increase of black spots, both of which might have collapsed with introgression by hatchery fish. These results suggest the possibility that introgression by stocked fish causes a change of phenotype in indigenous populations.

  4. Community-Based Adult Education for the Fisherwomen of Rajapalyam Fishing Village in Tuticorin, Southeast Coast of India

    ERIC Educational Resources Information Center

    Patterson, Jamila; Linden, Eva; Bierbrier, Christin; Lofgren, Inger; Edward, J. K. Patterson

    2008-01-01

    Rajapalyam village is located in the Tuticorin district along the biodiversity rich Gulf of Mannar coast in southeastern India. The people of this village are economically backward and most of the men are engaged in fishing. The fisherwomen of this village are less literate than the men, or illiterate. Adult education has been introduced to the…

  5. Factors and Mechanisms for Pharmacokinetic Differences between Pediatric Population and Adults

    PubMed Central

    Fernandez, Eva; Perez, Raul; Hernandez, Alfredo; Tejada, Pilar; Arteta, Marta; Ramos, Jose T.

    2011-01-01

    Many physiologic differences between children and adults may result in age-related changes in pharmacokinetics and pharmacodynamics. Factors such as gastric pH and emptying time, intestinal transit time, immaturity of secretion and activity of bile and pancreatic fluid among other factors determine the oral bioavailability of pediatric and adult populations. Anatomical, physiological and biochemical characteristics in children also affect the bioavailability of other routes of administration. Key factors explaining differences in drug distribution between the pediatric population and adults are membrane permeability, plasma protein binding and total body water. As far as drug metabolism is concerned, important differences have been found in the pediatric population compared with adults both for phase I and phase II metabolic enzymes. Immaturity of glomerular filtration, renal tubular secretion and tubular reabsorption at birth and their maturation determine the different excretion of drugs in the pediatric population compared to adults. PMID:24310425

  6. Population Connectivity and Phylogeography of a Coastal Fish, Atractoscion aequidens (Sciaenidae), across the Benguela Current Region: Evidence of an Ancient Vicariant Event

    PubMed Central

    Henriques, Romina; Potts, Warren M.; Santos, Carmen V.; Sauer, Warwick H. H.; Shaw, Paul W.

    2014-01-01

    Contemporary patterns of genetic diversity and population connectivity within species can be influenced by both historical and contemporary barriers to gene flow. In the marine environment, present day oceanographic features such as currents, fronts and upwelling systems can influence dispersal of eggs/larvae and/juveniles/adults, shaping population substructuring. The Benguela Current system in the southeastern Atlantic is one of the oldest upwelling systems in the world, and provides a unique opportunity to investigate the relative influence of contemporary and historical mechanisms shaping the evolutionary history of warm-temperate fish species. Using the genetic variation in the mitochondrial DNA Control Region and eight nuclear microsatellite DNA loci, we identified the presence of two highly divergent populations in a vagile and warm-temperate fish species, Atractoscion aequidens, across the Benguela region. The geographical distributions of the two populations, on either side of the perennial upwelling cell, suggest a strong correlation between the oceanographic features of the system and the breakdown of gene flow within this species. Genetic divergence (mtDNA φST = 0.902, microsatellite FST = 0.055: probability of genetic homogeneity for either marker = p<0.001), absence of migrants (less than 1% per generation) between populations and coalescent estimates of time since most recent common ancestor suggest that the establishment of the main oceanographic features of the system (2 million years ago), particularly the strengthening and position of the perennial upwelling cell, is the most likely mechanism behind the observed isolation. Concordance between mitochondrial and nuclear genetic markers indicates that isolation and divergence of the northern and southern Benguela populations of A. aequidens occurred deep in the past and has continued to the present day. These findings suggest that the Benguela Current system may constitute an ancient

  7. Genetic structuring among silverside fish (Atherinella brasiliensis) populations from different Brazilian regions

    NASA Astrophysics Data System (ADS)

    da Silva Cortinhas, Maria Cristina; Kersanach, Ralf; Proietti, Maíra; Dumont, Luiz Felipe Cestari; D'Incao, Fernando; Lacerda, Ana Luzia F.; Prata, Pedro Sanmartin; Matoso, Daniele Aparecida; Noleto, Rafael Bueno; Ramsdorf, Wanessa; Boni, Talge Aiex; Prioli, Alberto José; Cestari, Marta Margarete

    2016-09-01

    Estuaries are dynamic environments, key for the survival of innumerous ecologically or economically important fish species. Among these species are Neotropical silversides (Atherinella brasiliensis), which are resident and abundant in Brazilian estuaries and used as a complementary source of income and food for local communities. To better understand silverside populations in Brazil, we evaluated the genetic diversity, structure and demography of fish sampled at six estuaries from the northeastern to the southern coast, using Random Amplified Polymorphic DNA and mitochondrial DNA (D-loop) markers. High haplotype diversities (h ranging from 0.75 to 0.99) were found in all populations except Carapebus, located in Southeast Brazil (h = 0.54). A total of 69 mtDNA haplotypes were found, with Itaparica (Northeast Brazil) and Carapebus presenting only exclusive haplotypes, while some were shared among populations in the South. Strong regional structure was observed, with very high differentiation between Itaparica and Carapebus, as well as among these two populations and the ones from the Southern region (Paranaguá, Conceição, Camacho and Patos). Among southern areas, low/moderate structure was detected. Most populations showed unimodal mismatch distributions indicating recent demographic expansion, while Carapebus presented a multimodal distribution characteristic of a stable or bottlenecked population. Times since possible population expansion were highest in Itaparica (32,500 ya) and Carapebus (29,540 ya), while in the Southern region longest time was observed at Conceição (25,540 ya) and shortest at Patos (9720 ya). In a general manner, haplotype diversities were directly related to times since population expansions; again, Carapebus was the exception, displaying long time since expansion but low diversity, possibly due to a recent bottleneck caused by the isolation and human impacts this lagoon is subject to. Isolation by Distance was significant for Itaparica

  8. Seasonal weather patterns drive population vital rates and persistence in a stream fish.

    PubMed

    Kanno, Yoichiro; Letcher, Benjamin H; Hitt, Nathaniel P; Boughton, David A; Wofford, John E B; Zipkin, Elise F

    2015-05-01

    Climate change affects seasonal weather patterns, but little is known about the relative importance of seasonal weather patterns on animal population vital rates. Even when such information exists, data are typically only available from intensive fieldwork (e.g., mark-recapture studies) at a limited spatial extent. Here, we investigated effects of seasonal air temperature and precipitation (fall, winter, and spring) on survival and recruitment of brook trout (Salvelinus fontinalis) at a broad spatial scale using a novel stage-structured population model. The data were a 15-year record of brook trout abundance from 72 sites distributed across a 170-km-long mountain range in Shenandoah National Park, Virginia, USA. Population vital rates responded differently to weather and site-specific conditions. Specifically, young-of-year survival was most strongly affected by spring temperature, adult survival by elevation and per-capita recruitment by winter precipitation. Low fall precipitation and high winter precipitation, the latter of which is predicted to increase under climate change for the study region, had the strongest negative effects on trout populations. Simulations show that trout abundance could be greatly reduced under constant high winter precipitation, consistent with the expected effects of gravel-scouring flows on eggs and newly hatched individuals. However, high-elevation sites would be less vulnerable to local extinction because they supported higher adult survival. Furthermore, the majority of brook trout populations are projected to persist if high winter precipitation occurs only intermittently (≤3 of 5 years) due to density-dependent recruitment. Variable drivers of vital rates should be commonly found in animal populations characterized by ontogenetic changes in habitat, and such stage-structured effects may increase population persistence to changing climate by not affecting all life stages simultaneously. Yet, our results also demonstrate that

  9. Seasonal weather patterns drive population vital rates and persistence in a stream fish.

    PubMed

    Kanno, Yoichiro; Letcher, Benjamin H; Hitt, Nathaniel P; Boughton, David A; Wofford, John E B; Zipkin, Elise F

    2015-05-01

    Climate change affects seasonal weather patterns, but little is known about the relative importance of seasonal weather patterns on animal population vital rates. Even when such information exists, data are typically only available from intensive fieldwork (e.g., mark-recapture studies) at a limited spatial extent. Here, we investigated effects of seasonal air temperature and precipitation (fall, winter, and spring) on survival and recruitment of brook trout (Salvelinus fontinalis) at a broad spatial scale using a novel stage-structured population model. The data were a 15-year record of brook trout abundance from 72 sites distributed across a 170-km-long mountain range in Shenandoah National Park, Virginia, USA. Population vital rates responded differently to weather and site-specific conditions. Specifically, young-of-year survival was most strongly affected by spring temperature, adult survival by elevation and per-capita recruitment by winter precipitation. Low fall precipitation and high winter precipitation, the latter of which is predicted to increase under climate change for the study region, had the strongest negative effects on trout populations. Simulations show that trout abundance could be greatly reduced under constant high winter precipitation, consistent with the expected effects of gravel-scouring flows on eggs and newly hatched individuals. However, high-elevation sites would be less vulnerable to local extinction because they supported higher adult survival. Furthermore, the majority of brook trout populations are projected to persist if high winter precipitation occurs only intermittently (≤3 of 5 years) due to density-dependent recruitment. Variable drivers of vital rates should be commonly found in animal populations characterized by ontogenetic changes in habitat, and such stage-structured effects may increase population persistence to changing climate by not affecting all life stages simultaneously. Yet, our results also demonstrate that

  10. Population dynamics of a parasite Pallisentis in two species of fish Channa punctatus and Channa striatus.

    PubMed

    Gupta, N; Singhal, P; Gupta, D K

    2012-03-01

    In an aquatic environment, there is a profound and inverse relationship between environment quality and disease status of fish. Parasites are one of the most serious limiting factors in aquaculture. Therefore, the present investigation has been undertaken to sort out the population dynamics of Pallisentis (Acanthocephala), in relation to host sex from freshwater fishes, Channa of Rohilkhand region. A total of 517 fishes (Channa punctatus, n = 198 and C. striatus, n = 319) were examined regularly from August 2006 to February 2010. Overall prevalence of Pallisentis in C. striatus was higher in females (67.78%) as compared to males (63.52%). In case of C. punctatus, overall prevalence of Pallisentis was higher in males (53.77%) as compared to females (52.17%) whereas, relative density was higher in females (61.41%) than in males (52.72%). Intensity (2-3 parasite/host, in both sexes), density (1.36 in males and 1.69 in females) and infection index (0.73 in males and 0.88 in females) were recorded.

  11. Adult survival and population growth rate in Colorado big brown bats (Eptesicus fuscus)

    USGS Publications Warehouse

    O'Shea, T.J.; Ellison, L.E.; Stanley, T.R.

    2011-01-01

    We studied adult survival and population growth at multiple maternity colonies of big brown bats (Eptesicus fuscus) in Fort Collins, Colorado. We investigated hypotheses about survival using information-theoretic methods and mark-recapture analyses based on passive detection of adult females tagged with passive integrated transponders. We constructed a 3-stage life-history matrix model to estimate population growth rate (??) and assessed the relative importance of adult survival and other life-history parameters to population growth through elasticity and sensitivity analysis. Annual adult survival at 5 maternity colonies monitored from 2001 to 2005 was estimated at 0.79 (95% confidence interval [95% CI] = 0.77-0.82). Adult survival varied by year and roost, with low survival during an extreme drought year, a finding with negative implications for bat populations because of the likelihood of increasing drought in western North America due to global climate change. Adult survival during winter was higher than in summer, and mean life expectancies calculated from survival estimates were lower than maximum longevity records. We modeled adult survival with recruitment parameter estimates from the same population. The study population was growing (?? = 1.096; 95% CI = 1.057-1.135). Adult survival was the most important demographic parameter for population growth. Growth clearly had the highest elasticity to adult survival, followed by juvenile survival and adult fecundity (approximately equivalent in rank). Elasticity was lowest for fecundity of yearlings. The relative importances of the various life-history parameters for population growth rate are similar to those of large mammals. ?? 2011 American Society of Mammalogists.

  12. Association of blood mercury concentrations with atopic dermatitis in adults: a population-based study in Korea.

    PubMed

    Park, Hyejin; Kim, Kisok

    2011-05-01

    Atopic dermatitis is one of the most common inflammatory skin diseases among children and adults. Although the risk factors for atopic dermatitis have not yet been fully identified, exposure to mercury may be an important environmental risk factor. The objective of this study was to evaluate the association between mercury body burden and prevalence of atopic dermatitis in an adult population. We recruited participants (n=1990) aged 20 years or older, using stratified random sampling of Korean census blocks. Demographic characteristics and medical history of atopic dermatitis were collected from participants by questionnaire, and mercury levels were determined by an analysis of blood samples. We found that demographic factors such as sex, age, alcohol drinking status, income, and fish or shellfish consumption were important covariates determining blood mercury concentration. Sex and cigarette smoking status were important demographic variables affecting the prevalence of atopic dermatitis. After adjusting for demographic factors, blood mercury concentrations were positively associated with lifetime prevalence of atopic dermatitis [odds ratio (OR), highest vs. lowest tertile=1.50; 95% confidence interval (CI), 1.02-2.21; p for trend=0.057]. This association became stronger for 1-year prevalence of atopic dermatitis (OR, highest vs. lowest tertile=1.82; 95% CI, 1.17-2.83; p for trend=0.026). Mercury body burden and atopic dermatitis prevalence vary across demographic characteristics, and increased blood level of mercury was related to an incidence of atopic dermatitis in this adult population.

  13. Eggshell and egg yolk proteins in fish: hepatic proteins for the next generation: oogenetic, population, and evolutionary implications of endocrine disruption

    PubMed Central

    Arukwe, Augustine; Goksøyr, Anders

    2003-01-01

    The oocyte is the starting point for a new generation. Most of the machinery for DNA and protein synthesis needed for the developing embryo is made autonomously by the fertilized oocyte. However, in fish and in many other oviparous vertebrates, the major constituents of the egg, i.e. yolk and eggshell proteins, are synthesized in the liver and transported to the oocyte for uptake. Vitellogenesis, the process of yolk protein (vitellogenin) synthesis, transport, and uptake into the oocyte, and zonagenesis, the synthesis of eggshell zona radiata proteins, their transport and deposition by the maturing oocyte, are important aspects of oogenesis. The many molecular events involved in these processes require tight, coordinated regulation that is under strict endocrine control, with the female sex steroid hormone estradiol-17β in a central role. The ability of many synthetic chemical compounds to mimic this estrogen can lead to unscheduled hepatic synthesis of vitellogenin and zona radiata proteins, with potentially detrimental effects to the adult, the egg, the developing embryo and, hence, to the recruitment to the fish population. This has led to the development of specific and sensitive assays for these proteins in fish, and the application of vitellogenin and zona radiata proteins as informative biomarkers for endocrine disrupting effects of chemicals and effluents using fish as test organisms. The genes encoding these important reproductive proteins are conserved in the animal kingdom and are products of several hundred million years of evolution. PMID:12685931

  14. Genetic diversity despite population collapse in a critically endangered marine fish: the smalltooth sawfish (Pristis pectinata).

    PubMed

    Chapman, Demian D; Simpfendorfer, Colin A; Wiley, Tonya R; Poulakis, Gregg R; Curtis, Caitlin; Tringali, Michael; Carlson, John K; Feldheim, Kevin A

    2011-01-01

    Sawfish (family Pristidae) are among the most critically endangered marine fish in the world, yet very little is known about how genetic bottlenecks, genetic drift, and inbreeding depression may be affecting these elasmobranchs. In the US Atlantic, the smalltooth sawfish (Pristis pectinata) has declined to 1-5% of its abundance in the 1900s, and its core distribution has contracted to southwest Florida. We used 8 polymorphic microsatellite markers to show that this remnant population still exhibits high genetic diversity in terms of average allelic richness (18.23), average alleles per locus (18.75, standard deviation [SD] 6.6) and observed heterozygosity (0.43-0.98). Inbreeding is rare (mean individual internal relatedness = -0.02, SD 0.14; F(IS) = -0.011, 95% confidence interval [CI] = -0.039 to 0.011), even though the estimated effective population size (N(e)) is modest (250-350, 95% CI = 142-955). Simulations suggest that the remnant smalltooth sawfish population will probably retain >90% of its current genetic diversity over the next century even at the lower estimate of N(e). There is no evidence of a genetic bottleneck accompanying last century's demographic bottleneck, and we discuss hypotheses that could explain this. We also discuss features of elasmobranch life history and population biology that could make them less vulnerable than other large marine vertebrates to genetic change associated with reduced population size.

  15. Population genetic structure of Earth's largest fish, the whale shark (Rhincodon typus).

    PubMed

    Castro, A L F; Stewart, B S; Wilson, S G; Hueter, R E; Meekan, M G; Motta, P J; Bowen, B W; Karl, S A

    2007-12-01

    Large pelagic vertebrates pose special conservation challenges because their movements generally exceed the boundaries of any single jurisdiction. To assess the population structure of whale sharks (Rhincodon typus), we sequenced complete mitochondrial DNA control regions from individuals collected across a global distribution. We observed 51 single site polymorphisms and 8 regions with indels comprising 44 haplotypes in 70 individuals, with high haplotype (h = 0.974 +/- 0.008) and nucleotide diversity (pi = 0.011 +/- 0.006). The control region has the largest length variation yet reported for an elasmobranch (1143-1332 bp). Phylogenetic analyses reveal no geographical clustering of lineages and the most common haplotype was distributed globally. The absence of population structure across the Indian and Pacific basins indicates that oceanic expanses and land barriers in Southeast Asia are not impediments to whale shark dispersal. We did, however, find significant haplotype frequency differences (AMOVA, Phi(ST) = 0.107, P < 0.001) principally between the Atlantic and Indo-Pacific populations. In contrast to other recent surveys of globally distributed sharks, we find much less population subdivision and no evidence for cryptic evolutionary partitions. Discovery of the mating and pupping areas of whale sharks is key to further population genetic studies. The global pattern of shared haplotypes in whale sharks provides a compelling argument for development of broad international approaches for management and conservation of Earth's largest fish.

  16. The impact of United States recreational fisheries on marine fish populations.

    PubMed

    Coleman, Felicia C; Figueira, Will F; Ueland, Jeffrey S; Crowder, Larry B

    2004-09-24

    We evaluated the commercial and recreational fishery landings over the past 22 years, first at the national level, then for populations of concern (those that are overfished or experiencing overfishing), and finally by region. Recreational landings in 2002 account for 4% of total marine fish landed in the United States. With large industrial fisheries excluded (e.g., menhaden and pollock), the recreational component rises to 10%. Among populations of concern, recreational landings in 2002 account for 23% of the total nationwide, rising to 38% in the South Atlantic and 64% in the Gulf of Mexico. Moreover, it affects many of the most-valued overfished species-including red drum, bocaccio, and red snapper-all of which are taken primarily in the recreational fishery.

  17. [Advanced approaches to studying the population diversity of marine fishes: new opportunities for fisheries control and management].

    PubMed

    Zelenina, D A; Martinson, Ia T; Ogden, R; Volkov, A A; Zelenina, I A; Carvalho, G R

    2011-12-01

    Recent conceptual and technological advances now enable fisheries geneticists to detect and monitor the dynamics and distribution of marine fish populations more effectively than ever before. Information on the extent of genetically-based divergence among populations, so-called "population diversity", is crucial in the quest to manage exploited living resources sustainably since it endows evolutionary potential in the face of environmental change. The generally limited dialogue between scientists, fisheries managers and policy makers, however, continues to constrain integration of population genetic data into tangible policy applications. Largely drawing on the approach and outputs from a European research project, FishPopTrace, we provide an example how the uncovering of marine fish population diversity enables players from genetics, forensics, management and the policy realm to generate a framework tackling key policy-led questions relating to illegal fishing and traceability. We focus on the use of single-nucleotide polymorphisms (SNPs) in European populations of cod, herring, hake and common sole, and explore how forensics together with a range of analytical approaches, and combined with improved communication of research results to stakeholders, can be used to secure sufficiently robust, tractable and targeted data for effective engagement between science and policy. The essentially binary nature of SNPs, together with generally elevated signals of population discrimination by SNPs under selection, allowed assignment of fish to populations from more areas and with higher certainty than previously possible, reaching standards suitable for use in a court of law. We argue that the use of such tools in enforcement and deterrence, together with the greater integration of population genetic principles and methods into fisheries management, provide tractable elements in the arsenal of tools to achieve sustainable exploitation and conservation of depleted marine fish

  18. Cognitive performance in older adults is inversely associated with fish consumption but not erythrocyte membrane n-3 fatty acids.

    PubMed

    Danthiir, Vanessa; Hosking, Diane; Burns, Nicholas R; Wilson, Carlene; Nettelbeck, Ted; Calvaresi, Eva; Clifton, Peter; Wittert, Gary A

    2014-03-01

    Higher n-3 (ω-3) polyunsaturated fatty acids (PUFAs) and fish intake may help maintain cognitive function in older age. However, evidence is inconsistent; few studies have examined the relation in cognitively healthy individuals across numerous cognitive domains, and none to our knowledge have considered lifetime fish intake. We examined associations between multiple domains of cognition and erythrocyte membrane n-3 PUFA proportions and historical and contemporary fish intake in 390 normal older adults, analyzing baseline data from the Older People, Omega-3, and Cognitive Health trial. We measured n-3 PUFA in erythrocyte membranes, and we assessed historical and contemporary fish intake by food-frequency questionnaires. We assessed cognitive performance on reasoning, working memory, short-term memory, retrieval fluency, perceptual speed, simple/choice reaction time, speed of memory-scanning, reasoning speed, inhibition, and psychomotor speed. Cognitive outcomes for each construct were factor scores from confirmatory factor analysis. Multiple linear regression models controlled for a number of potential confounding factors, including age, education, sex, apolipoprotein E-ε 4 allele, physical activity, smoking, alcohol intake, socioeconomic variables, and other health-related variables. Higher erythrocyte membrane eicosapaentonoic acid proportions predicted slower perceptual and reasoning speed in females, which was attenuated once current fish intake was controlled. No other associations were present between n-3 PUFA proportions and cognitive performance. Higher current fish consumption predicted worse performance on several cognitive speed constructs. Greater fish consumption in childhood predicted slower perceptual speed and simple/choice reaction time. We found no evidence to support the hypothesis that higher proportions of long-chain n-3 fatty acids or fish intake benefits cognitive performance in normal older adults.

  19. Impact of entrainment and impingement on fish populations in the Hudson River estuary. Volume I. Entrainment-impact estimates for six fish populations inhabiting the Hudson River estuary

    SciTech Connect

    Boreman, J.; Barnthouse, L.W.; Vaughn, D.S.; Goodyear, C.P.; Christensen, S.W.; Kumar, K.D.; Kirk, B.L.; Van Winkle, W.

    1982-01-01

    This volume is concerned with the estimation of the direct (or annual) entrainment impact of power plants on populations of striped bass, white perch, Alosa spp. (blueback herring and alewife), American shad, Atlantic tomcod, and bay anchovy in the Hudson River estuary. Entrainment impact results from the killing of fish eggs, larvae, and young juveniles that are contained in the cooling water cycled through a power plant. An Empirical Transport Model (ETM) is presented as the means of estimating a conditional entrainment mortality rate (defined as the fraction of a year class which would be killed due to entrainment in the absence of any other source of mortality). Most of this volume is concerned with the estimation of several parameters required by the ETM: physical input parameters (e.g., power-plant withdrawal flow rates); the longitudinal distribution of ichthyoplankton in time and space; the duration of susceptibility of the vulnerable organisms; the W-factors, which express the ratios of densities of organisms in power plant intakes to densities of organisms in the river; and the entrainment mortality factors (f-factors), which express the probability that an organism will be killed if it is entrained. Once these values are obtained, the ETM is used to estimate entrainment impact for both historical and projected conditions.

  20. Larval retention and connectivity among populations of corals and reef fishes: history, advances and challenges

    NASA Astrophysics Data System (ADS)

    Jones, G. P.; Almany, G. R.; Russ, G. R.; Sale, P. F.; Steneck, R. S.; van Oppen, M. J. H.; Willis, B. L.

    2009-06-01

    The extent of larval dispersal on coral reefs has important implications for the persistence of coral reef metapopulations, their resilience and recovery from an increasing array of threats, and the success of protective measures. This article highlights a recent dramatic increase in research effort and a growing diversity of approaches to the study of larval retention within (self-recruitment) and dispersal among (connectivity) isolated coral reef populations. Historically, researchers were motivated by alternative hypotheses concerning the processes limiting populations and structuring coral reef assemblages, whereas the recent impetus has come largely from the need to incorporate dispersal information into the design of no-take marine protected area (MPA) networks. Although the majority of studies continue to rely on population genetic approaches to make inferences about dispersal, a wide range of techniques are now being employed, from small-scale larval tagging and paternity analyses, to large-scale biophysical circulation models. Multiple approaches are increasingly being applied to cross-validate and provide more realistic estimates of larval dispersal. The vast majority of empirical studies have focused on corals and fishes, where evidence for both extremely local scale patterns of self-recruitment and ecologically significant connectivity among reefs at scales of tens of kilometers (and in some cases hundreds of kilometers) is accumulating. Levels of larval retention and the spatial extent of connectivity in both corals and fishes appear to be largely independent of larval duration or reef size, but may be strongly influenced by geographic setting. It is argued that high levels of both self-recruitment and larval import can contribute to the resilience of reef populations and MPA networks, but these benefits will erode in degrading reef environments.

  1. Effects of metal contamination from mine tailings on allozyme distributions of populations of Great Plains fishes

    SciTech Connect

    Brown, K.; Roark, S.

    1995-12-31

    This study was conducted to assess the effects of zinc and lead on genetic variability of minnow populations (Gambusia affinis, Pimephales notatus, and Fundulus notatus) sampled from two creeks, one receiving mine drainage (Willow Creek) and one reference (Brush Creek), in the Tri-State Mining district in Kansas. Zinc and lead concentrations were greater in water samples taken from sites in Willow Creek compared to sites sampled in Brush Creek. While total numbers of fish captured from Willow Creek were smaller than numbers taken from Brush Creek, there were no differences in these fish communities for estimates of species diversity, richness and evenness. Genetic differentiation within creeks was rare. However, there was significant differentiation between creeks for allozymes of the enzymes glucose phosphate isomerase (GPI) in F. notatus and P. notatus, malate dehydrogenase (MDH) in G. affinis, and phosphogluconate dehydrogenase (PGDH) in F. notatus. Proportions of heterozygous genotypes of P. notatus and G. affinis were higher in Willow Creek compared to Brush Creek. In vitro experiments were conducted to assess the effects of zinc and lead on sensitivity of enzyme staining during electrophoresis. Results indicated allozyme sensitivity to zinc for GPI and PGDH loci. Other studies suggest that zinc competitively competes with magnesium as a cofactor for these enzymes. Allozymes did not exhibit differential sensitivity to lead. The significant differentiation between creek populations and the results of the in vitro tests indicate a selective effect of zinc on allozymic distributions of these fishes. These results demonstrate the potential use of genetic variability as a bioindicator of heavy metal contamination.

  2. Effects of metal contamination from mine tailings on allozyme distributions of populations of Great Plains fishes

    SciTech Connect

    Roark, S.; Brown, K.

    1996-06-01

    This study was conducted to assess the effects of zinc and lead on genetic variability of minnow populations (Gambusia affinis, Pimephales notatus, and Fundulus notatus) sampled from two creeks, one receiving mine drainage (Willow Creek) and one reference (Brush Creek), in the Tri-State Mining District in Kansas. Zinc and lead concentrations were greater in water samples taken from sites in Willow Creek compared to sites sampled in Brush Creek. Although total numbers of fish captured from Willow Creek were smaller than numbers taken from Brush Creek, there were no differences in these fish communities for estimates of species diversity, richness, and evenness. Genetic differentiation within creeks was rare. However, there was significant differentiation between creeks for allozymes of the enzymes glucose phosphate isomerase (Gpi) in F. notatus and P. notatus, malate dehydrogenase (Mdh) in G. affinis, and phosphogluconate dehydrogenase (Pgdh) in F. notatus. Proportions of heterozygous genotypes of P. notatus and G. affinis were higher in Willow Creek compared to Brush Creek. In vitro experiments were conducted to assess the effects of zinc and lead on sensitivity of enzyme staining during electrophoresis. Results indicated allozyme sensitivity to zinc for Gpi and Pgdh loci, but not for products of the Mdh locus. No sensitivity to lead was noted for allozymes. The significant differentiation between creek populations and the results of the in vitro tests indicate a selective effect of zinc on allozymic distributions of these fishes. These results provide additional support for the use of genetic structure and variability as a bioindicator of heavy metal contamination.

  3. Disruptive sexual selection on male nuptial coloration in an experimental hybrid population of cichlid fish.

    PubMed

    Stelkens, Rike B; Pierotti, Michele E R; Joyce, Domino A; Smith, Alan M; van der Sluijs, Inke; Seehausen, Ole

    2008-09-12

    Theory suggests that genetic polymorphisms in female mating preferences may cause disruptive selection on male traits, facilitating phenotypic differentiation despite gene flow, as in reinforcement or other models of speciation with gene flow. Very little experimental data have been published to test the assumptions regarding the genetics of mate choice that such theory relies on. We generated a population segregating for female mating preferences and male colour dissociated from other species differences by breeding hybrids between species of the cichlid fish genus Pundamilia. We measured male mating success as a function of male colour. First, we demonstrate that non-hybrid females of both species use male nuptial coloration for choosing mates, but with inversed preferences. Second, we show that variation in female mating preferences in an F2 hybrid population generates a quadratic fitness function for male coloration suggestive of disruptive selection: intermediate males obtained fewer matings than males at either extreme of the colour range. If the genetics of female mate choice in Pundamilia are representative for those in other species of Lake Victoria cichlid fish, it may help explain the origin and maintenance of phenotypic diversity despite some gene flow.

  4. Habitat Discontinuities Separate Genetically Divergent Populations of a Rocky Shore Marine Fish

    PubMed Central

    Knutsen, Halvor; Jorde, Per Erik

    2016-01-01

    Habitat fragmentation has been suggested to be responsible for major genetic differentiations in a range of marine organisms. In this study, we combined genetic data and environmental information to unravel the relative role of geography and habitat heterogeneity on patterns of genetic population structure of corkwing wrasse (Symphodus melops), a rocky shore species at the northern limit of its distribution range in Scandinavia. Our results revealed a major genetic break separating populations inhabiting the western and southern coasts of Norway. This genetic break coincides with the longest stretch of sand in the whole study area, suggesting habitat fragmentation as a major driver of genetic differentiation of this obligate rocky shore benthic fish in Scandinavia. The complex fjords systems extending along the western coast of Norway appeared responsible for further regional genetic structuring. Our findings indicate that habitat discontinuities may lead to significant genetic fragmentation over short geographical distances, even for marine species with a pelagic larval phase, as for this rocky shore fish. PMID:27706178

  5. Disruptive sexual selection on male nuptial coloration in an experimental hybrid population of cichlid fish.

    PubMed

    Stelkens, Rike B; Pierotti, Michele E R; Joyce, Domino A; Smith, Alan M; van der Sluijs, Inke; Seehausen, Ole

    2008-09-12

    Theory suggests that genetic polymorphisms in female mating preferences may cause disruptive selection on male traits, facilitating phenotypic differentiation despite gene flow, as in reinforcement or other models of speciation with gene flow. Very little experimental data have been published to test the assumptions regarding the genetics of mate choice that such theory relies on. We generated a population segregating for female mating preferences and male colour dissociated from other species differences by breeding hybrids between species of the cichlid fish genus Pundamilia. We measured male mating success as a function of male colour. First, we demonstrate that non-hybrid females of both species use male nuptial coloration for choosing mates, but with inversed preferences. Second, we show that variation in female mating preferences in an F2 hybrid population generates a quadratic fitness function for male coloration suggestive of disruptive selection: intermediate males obtained fewer matings than males at either extreme of the colour range. If the genetics of female mate choice in Pundamilia are representative for those in other species of Lake Victoria cichlid fish, it may help explain the origin and maintenance of phenotypic diversity despite some gene flow. PMID:18522918

  6. Big Spring spinedace and associated fish populations and habitat conditions in Condor Canyon, Meadow Valley Wash, Nevada

    USGS Publications Warehouse

    Jezorek, Ian G.; Connolly, Patrick J.; Munz, Carrie S.; Dixon, Chris

    2011-01-01

    Executive Summary: This project was designed to document habitat conditions and populations of native and non-native fish within the 8-kilometer Condor Canyon section of Meadow Valley Wash, Nevada, with an emphasis on Big Spring spinedace (Lepidomeda mollispinis pratensis). Other native fish present were speckled dace (Rhinichthys osculus) and desert sucker (Catostomus clarki). Big Spring spinedace were known to exist only within this drainage and were known to have been extirpated from a portion of their former habitat located downstream of Condor Canyon. Because of this extirpation and the limited distribution of Big Spring spinedace, the U.S. Fish and Wildlife Service listed this species as threatened under the Endangered Species Act in 1985. Prior to our effort, little was known about Big Spring spinedace populations or life histories and habitat associations. In 2008, personnel from the U.S. Geological Survey's Columbia River Research Laboratory began surveys of Meadow Valley Wash in Condor Canyon. Habitat surveys characterized numerous variables within 13 reaches, thermologgers were deployed at 9 locations to record water temperatures, and fish populations were surveyed at 22 individual sites. Additionally, fish were tagged with Passive Integrated Transponder (PIT) tags, which allowed movement and growth information to be collected on individual fish. The movements of tagged fish were monitored with a combination of recapture events and stationary in-stream antennas, which detected tagged fish. Meadow Valley Wash within Condor Canyon was divided by a 12-meter (m) waterfall known as Delmue Falls. About 6,100 m of stream were surveyed downstream of the falls and about 2,200 m of stream were surveyed upstream of the falls. Although about three-quarters of the surveyed stream length was downstream of Delmue Falls, the highest densities and abundance of native fish were upstream of the falls. Big Spring spinedace and desert sucker populations were highest near the

  7. CREATION OF A GEOGRAPHIC INFORMATION SYSTEM TO IDENTIFY AT-RISK POPULATIONS IN NEW JERSEY AND NEW YORK FOR CONSUMPTION OF CONTAMINATED FISH AND SEAFOOD

    EPA Science Inventory

    Project Objective: To identify at-risk populations, particularly women of child bearing years and young children, for consumption of contaminated fish and seafood via the use of geographically and demographically defined seafood consumption patterns and fish/seafood contaminatio...

  8. A phylogenetic analysis of egg size, clutch size, spawning mode, adult body size, and latitude in reef fishes

    NASA Astrophysics Data System (ADS)

    Kasimatis, Katja; Riginos, Cynthia

    2016-06-01

    Theoretical treatments of egg size in fishes suggest that constraints on reproductive output should create trade-offs between the size and number of eggs produced per spawn. For marine reef fishes, the observation of distinct reproductive care strategies (demersal guarding, egg scattering, and pelagic spawning) has additionally prompted speculation that these strategies reflect alternative fitness optima with selection on egg size differing by reproductive mode and perhaps latitude. Here, we aggregate data from 278 reef fish species and test whether clutch size, reproductive care, adult body size, and latitudinal bands (i.e., tropical, subtropical, and temperate) predict egg size, using a statistically unified framework that accounts for phylogenetic correlations among traits. We find no inverse relationship between species egg size and clutch size, but rather that egg size differs by reproductive mode (mean volume for demersal eggs = 1.22 mm3, scattered eggs = 0.18 mm3, pelagic eggs = 0.52 mm3) and that clutch size is strongly correlated with adult body size. Larger eggs were found in temperate species compared with tropical species in both demersal guarders and pelagic spawners, but this difference was not strong when accounting for phylogenetic correlations, suggesting that differences in species composition underlies regional differences in egg size. In summary, demersal guarders are generally small fishes with small clutch sizes that produce large eggs. Pelagic spawners and egg scatterers are variable in adult and clutch size. Although pelagic spawned eggs are variable in size, those of scatterers are consistently small.

  9. Characterization of fish assemblages and population structure of freshwater fish in two Tunisian reservoirs: implications for fishery management.

    PubMed

    Mili, Sami; Ennouri, Rym; Dhib, Amel; Laouar, Houcine; Missaoui, Hechmi; Aleya, Lotfi

    2016-06-01

    To monitor and assess the state of Tunisian freshwater fisheries, two surveys were undertaken at Ghezala and Lahjar reservoirs. Samples were taken in April and May 2013, a period when the fish catchability is high. The selected reservoirs have different surface areas and bathymetries. Using multi-mesh gill nets (EN 14575 amended) designed for sampling fish in lakes, standard fishing methods were applied to estimate species composition, abundance, biomass, and size distribution. Four species were caught in the two reservoirs: barbel, mullet, pike-perch, and roach. Fish abundance showed significant change according to sampling sites, depth strata, and the different mesh sizes used. From the reservoir to the tributary, it was concluded that fish biomass distribution was governed by depth and was most abundant in the upper water layers. Species size distribution differed significantly between the two reservoirs, exceeding the length at first maturity. Species composition and abundance were greater in Lahjar reservoir than in Ghezala. Both reservoirs require support actions to improve fish productivity. PMID:27220503

  10. Characterization of fish assemblages and population structure of freshwater fish in two Tunisian reservoirs: implications for fishery management.

    PubMed

    Mili, Sami; Ennouri, Rym; Dhib, Amel; Laouar, Houcine; Missaoui, Hechmi; Aleya, Lotfi

    2016-06-01

    To monitor and assess the state of Tunisian freshwater fisheries, two surveys were undertaken at Ghezala and Lahjar reservoirs. Samples were taken in April and May 2013, a period when the fish catchability is high. The selected reservoirs have different surface areas and bathymetries. Using multi-mesh gill nets (EN 14575 amended) designed for sampling fish in lakes, standard fishing methods were applied to estimate species composition, abundance, biomass, and size distribution. Four species were caught in the two reservoirs: barbel, mullet, pike-perch, and roach. Fish abundance showed significant change according to sampling sites, depth strata, and the different mesh sizes used. From the reservoir to the tributary, it was concluded that fish biomass distribution was governed by depth and was most abundant in the upper water layers. Species size distribution differed significantly between the two reservoirs, exceeding the length at first maturity. Species composition and abundance were greater in Lahjar reservoir than in Ghezala. Both reservoirs require support actions to improve fish productivity.

  11. Does mating behaviour affect connectivity in marine fishes? Comparative population genetics of two protogynous groupers (Family Serranidae).

    PubMed

    Portnoy, D S; Hollenbeck, C M; Renshaw, M A; Cummings, N J; Gold, J R

    2013-01-01

    Pelagic larval duration (PLD) has been hypothesized to be the primary predictor of connectivity in marine fishes; however, few studies have examined the effects that adult reproductive behaviour may have on realized dispersal. We assessed gene flow (connectivity) by documenting variation in microsatellites and mitochondrial DNA sequences in two protogynous species of groupers, the aggregate spawning red hind, Epinephelus guttatus, and the single-male, harem-spawning coney, Cephalopholis fulva, to ask whether reproductive strategy affects connectivity. Samples of both species were obtained from waters off three islands (Puerto Rico, St. Thomas and St. Croix) in the Caribbean Sea. Despite the notion that aggregate spawning of red hind may facilitate larval retention, stronger signals of population structure were detected in the harem-spawning coney. Heterogeneity and/or inferred barriers, based on microsatellites, involved St. Croix (red hind and coney) and the west coast of Puerto Rico (coney). Heterogeneity and/or inferred barriers, based on mitochondrial DNA, involved St. Croix (coney only). Genetic divergence in both species was stronger for microsatellites than for mitochondrial DNA, suggesting sex-biased dispersal in both species. Long-term migration rates, based on microsatellites, indicated asymmetric gene flow for both species in the same direction as mean surface currents in the region. Red hind had higher levels of variation in microsatellites and lower levels of variation in mitochondrial DNA. Long-term effective size and effective number of breeders were greater for red hind; estimates of θ(f) , a proxy for long-term effective female size, were the same in both species. Patterns of gene flow in both species appear to stem in part from shared aspects of larval and adult biology, local bathymetry and surface current patterns. Differences in connectivity and levels of genetic variation between the species, however, likely stem from differences in behaviour

  12. Does mating behaviour affect connectivity in marine fishes? Comparative population genetics of two protogynous groupers (Family Serranidae).

    PubMed

    Portnoy, D S; Hollenbeck, C M; Renshaw, M A; Cummings, N J; Gold, J R

    2013-01-01

    Pelagic larval duration (PLD) has been hypothesized to be the primary predictor of connectivity in marine fishes; however, few studies have examined the effects that adult reproductive behaviour may have on realized dispersal. We assessed gene flow (connectivity) by documenting variation in microsatellites and mitochondrial DNA sequences in two protogynous species of groupers, the aggregate spawning red hind, Epinephelus guttatus, and the single-male, harem-spawning coney, Cephalopholis fulva, to ask whether reproductive strategy affects connectivity. Samples of both species were obtained from waters off three islands (Puerto Rico, St. Thomas and St. Croix) in the Caribbean Sea. Despite the notion that aggregate spawning of red hind may facilitate larval retention, stronger signals of population structure were detected in the harem-spawning coney. Heterogeneity and/or inferred barriers, based on microsatellites, involved St. Croix (red hind and coney) and the west coast of Puerto Rico (coney). Heterogeneity and/or inferred barriers, based on mitochondrial DNA, involved St. Croix (coney only). Genetic divergence in both species was stronger for microsatellites than for mitochondrial DNA, suggesting sex-biased dispersal in both species. Long-term migration rates, based on microsatellites, indicated asymmetric gene flow for both species in the same direction as mean surface currents in the region. Red hind had higher levels of variation in microsatellites and lower levels of variation in mitochondrial DNA. Long-term effective size and effective number of breeders were greater for red hind; estimates of θ(f) , a proxy for long-term effective female size, were the same in both species. Patterns of gene flow in both species appear to stem in part from shared aspects of larval and adult biology, local bathymetry and surface current patterns. Differences in connectivity and levels of genetic variation between the species, however, likely stem from differences in behaviour

  13. Validation of a U.S. Adult Social Self-Efficacy Inventory in Chinese Populations

    ERIC Educational Resources Information Center

    Fan, Jinyan; Meng, Hui; Gao, Xiangping; Lopez, Felix J.; Liu, Cong

    2010-01-01

    The authors report a series of efforts to validate a U.S. adult social self-efficacy inventory, the Perceived Social Self-Efficacy scale (PSSE), in Chinese populations. They argue that the construct underlying the PSSE scale constitutes an important component of Chinese adult social self-efficacy, which was confirmed in focus group discussions.…

  14. The National Blueprint for Promoting Physical Activity in the Mid-Life and Older Adult Population

    ERIC Educational Resources Information Center

    Chodzko-Zajko, Wojtek; Sheppard, Lisa; Senior, Jane; Park, Chae-Hee; Mockenhaupt, Robin; Bazzarre, Terry

    2005-01-01

    The National Blueprint: Increasing Physical Activity Among Adults Age 50 and Older was designed to develop a national strategy for the promotion of physically active lifestyles among the mid-life and older adult population. The Blueprint identifies barriers to physical activity in the areas of research, home and community programs, medical…

  15. Prevalence of Chronic Medical Conditions in Adults with Mental Retardation: Comparison with the General Population.

    ERIC Educational Resources Information Center

    Kapell, Deborah; Nightingale, Beryle; Rodriguez, Ana; Lee, Joseph H.; Zigman, Warren B.; Schupf, Nicole

    1998-01-01

    A study interviewed caregivers and reviewed medical records of 278 adults with mental retardation with and without Down syndrome. The adults with mental retardation had age-related disorders comparable to those in the general population, but there was an increased frequency of thyroid disorders, nonischemic heart disorders, and sensory impairment.…

  16. Resilience and tipping points of an exploited fish population over six decades.

    PubMed

    Vasilakopoulos, Paraskevas; Marshall, C Tara

    2015-05-01

    Complex natural systems with eroded resilience, such as populations, ecosystems and socio-ecological systems, respond to small perturbations with abrupt, discontinuous state shifts, or critical transitions. Theory of critical transitions suggests that such systems exhibit fold bifurcations featuring folded response curves, tipping points and alternate attractors. However, there is little empirical evidence of fold bifurcations occurring in actual complex natural systems impacted by multiple stressors. Moreover, resilience of complex systems to change currently lacks clear operational measures with generic application. Here, we provide empirical evidence for the occurrence of a fold bifurcation in an exploited fish population and introduce a generic measure of ecological resilience based on the observed fold bifurcation attributes. We analyse the multivariate development of Barents Sea cod (Gadus morhua), which is currently the world's largest cod stock, over six decades (1949-2009), and identify a population state shift in 1981. By plotting a multivariate population index against a multivariate stressor index, the shift mechanism was revealed suggesting that the observed population shift was a nonlinear response to the combined effects of overfishing and climate change. Annual resilience values were estimated based on the position of each year in relation to the fitted attractors and assumed tipping points of the fold bifurcation. By interpolating the annual resilience values, a folded stability landscape was fit, which was shaped as predicted by theory. The resilience assessment suggested that the population may be close to another tipping point. This study illustrates how a multivariate analysis, supported by theory of critical transitions and accompanied by a quantitative resilience assessment, can clarify shift mechanisms in data-rich complex natural systems. PMID:25545249

  17. Resilience and tipping points of an exploited fish population over six decades.

    PubMed

    Vasilakopoulos, Paraskevas; Marshall, C Tara

    2015-05-01

    Complex natural systems with eroded resilience, such as populations, ecosystems and socio-ecological systems, respond to small perturbations with abrupt, discontinuous state shifts, or critical transitions. Theory of critical transitions suggests that such systems exhibit fold bifurcations featuring folded response curves, tipping points and alternate attractors. However, there is little empirical evidence of fold bifurcations occurring in actual complex natural systems impacted by multiple stressors. Moreover, resilience of complex systems to change currently lacks clear operational measures with generic application. Here, we provide empirical evidence for the occurrence of a fold bifurcation in an exploited fish population and introduce a generic measure of ecological resilience based on the observed fold bifurcation attributes. We analyse the multivariate development of Barents Sea cod (Gadus morhua), which is currently the world's largest cod stock, over six decades (1949-2009), and identify a population state shift in 1981. By plotting a multivariate population index against a multivariate stressor index, the shift mechanism was revealed suggesting that the observed population shift was a nonlinear response to the combined effects of overfishing and climate change. Annual resilience values were estimated based on the position of each year in relation to the fitted attractors and assumed tipping points of the fold bifurcation. By interpolating the annual resilience values, a folded stability landscape was fit, which was shaped as predicted by theory. The resilience assessment suggested that the population may be close to another tipping point. This study illustrates how a multivariate analysis, supported by theory of critical transitions and accompanied by a quantitative resilience assessment, can clarify shift mechanisms in data-rich complex natural systems.

  18. Cardiorespiratory performance and blood chemistry during swimming and recovery in three populations of elite swimmers: Adult sockeye salmon.

    PubMed

    Eliason, Erika J; Clark, Timothy D; Hinch, Scott G; Farrell, Anthony P

    2013-10-01

    Every year, millions of adult sockeye salmon (Oncorhynchus nerka) perform an arduous, once-in-a-lifetime migration up the Fraser River (BC, Canada) to return to their natal stream to spawn. The changes in heart rate, stroke volume, and arterio-venous oxygen extraction (i.e., factors determining rates of oxygen delivery to the tissues by the cardiovascular system) have never been directly and simultaneously measured along with whole animal oxygen uptake in a maximally swimming fish. Here, such measurements were made using three sockeye salmon populations (Early Stuart, Chilko and Quesnel), which each performed two consecutive critical swimming speed (Ucrit) challenges to provide a comprehensive quantification of cardiovascular physiology, oxygen status and blood chemistry associated with swimming and recovery. Swim performance, oxygen uptake, cardiac output, heart rate and stroke volume did not significantly vary at rest, during swimming or during recovery between populations or sexes. Despite incomplete metabolic recovery between swim challenges, all fish repeated their swim performance and similar quantitative changes in the cardiorespiratory variables were observed for each swim challenge. The high maximum cardiorespiratory performance and excellent repeat swim performance are clearly beneficial in allowing the salmon to maintain steady ground speeds and reach the distant spawning grounds in a timely manner. PMID:23880060

  19. Cardiorespiratory performance and blood chemistry during swimming and recovery in three populations of elite swimmers: Adult sockeye salmon.

    PubMed

    Eliason, Erika J; Clark, Timothy D; Hinch, Scott G; Farrell, Anthony P

    2013-10-01

    Every year, millions of adult sockeye salmon (Oncorhynchus nerka) perform an arduous, once-in-a-lifetime migration up the Fraser River (BC, Canada) to return to their natal stream to spawn. The changes in heart rate, stroke volume, and arterio-venous oxygen extraction (i.e., factors determining rates of oxygen delivery to the tissues by the cardiovascular system) have never been directly and simultaneously measured along with whole animal oxygen uptake in a maximally swimming fish. Here, such measurements were made using three sockeye salmon populations (Early Stuart, Chilko and Quesnel), which each performed two consecutive critical swimming speed (Ucrit) challenges to provide a comprehensive quantification of cardiovascular physiology, oxygen status and blood chemistry associated with swimming and recovery. Swim performance, oxygen uptake, cardiac output, heart rate and stroke volume did not significantly vary at rest, during swimming or during recovery between populations or sexes. Despite incomplete metabolic recovery between swim challenges, all fish repeated their swim performance and similar quantitative changes in the cardiorespiratory variables were observed for each swim challenge. The high maximum cardiorespiratory performance and excellent repeat swim performance are clearly beneficial in allowing the salmon to maintain steady ground speeds and reach the distant spawning grounds in a timely manner.

  20. Correlates of Suicide in the Older Adult Population in Quebec

    ERIC Educational Resources Information Center

    Preville, Michel; Boyer, Richard; Hebert, Rejean; Bravo, Gina; Seguin, Monique

    2005-01-01

    This study was undertaken to describe the characteristics of adults aged 60 years and over who committed suicide in Quebec in 1998?1999. In this study, 42.6% of the suicide cases presented mental disorders at the time of their death, mainly depression. Sixty-five (65.3%) percent of the suicide cases would have been considered as having a mental…

  1. Evidence for behavioral preference toward environmental concentrations of urban-use herbicides in a model adult fish.

    PubMed

    Tierney, Keith B; Sekela, Mark A; Cobbler, Christine E; Xhabija, Besa; Gledhill, Melissa; Ananvoranich, Sirinart; Zielinski, Barbara S

    2011-09-01

    Fish live in waters of contaminant flux. In three urban, fish-bearing waterways of British Columbia, Canada, we found the active ingredients of WeedEx, KillEx, and Roundup herbicide formulations (2,4-D, dicamba, glyphosate, and mecoprop) at low to high ng/L concentrations (0.26 to 309 ng/L) in routine conditions, i.e., no rain for at least one week. Following rain, these concentrations increased by an average of eightfold, suggesting runoff as a major route of herbicide introduction in these waterways. To determine whether fish might be able to limit point-source exposures through sensory-driven behaviors, we introduced pulses of representative herbicide mixtures to individual adult zebrafish (a model species) in flow-through tanks. Fish did the opposite of limit exposure; they chose to spend more time in pulses of herbicide mixtures representative of those that may occur with rain events. This attraction response was not altered by a previous 4-d exposure to lower concentrations of the mixtures, suggesting fish will not learn from previous exposures. However, previous exposures did alter an attraction response to an amino acid prevalent in food (L-alanine). The present study demonstrates that fish living within urban waterways may elect to place themselves in herbicide-contaminated environments and that these exposures may alter their behavioral responses to cues necessary for survival.

  2. The impacts of mobile fishing gear on seafloor habitats in the gulf of maine (Northwest Atlantic): Implications for conservation of fish populations

    USGS Publications Warehouse

    Auster, P.J.; Malatesta, R.J.; Langton, R.W.; Watling, Les; Valentine, P.C.; Donaldson, C.L.S.; Langton, E.W.; Shepard, A.N.; Babb, Ivar G.

    1996-01-01

    Fishing gear alters seafloor habitats, but the extent of these alterations, and their effects, have not been quantified extensively in the northwest Atlantic. Understanding the extent of these impacts, and their effects on populations of living marine resources, is needed to properly manage current and future levels of fishing effort and fishing power. For example, the entire U.S. side of the Gulf of Maine was impacted annually by mobile fishing gear between 1984 and 1990, based on calculations of area swept by trawl and dredge gear. Georges Bank was impacted three to nearly four times annually during the same period. Studies at three sites in the Gulf of Maine (off Swans Island, Jeffreys Bank, and Stellwagen Bank) showed that mobile fishing gear altered the physical structure (=complexity) of benthic habitats. Complexity was reduced by direct removal of biogenic (e.g., sponges, hydrozoans, bryozoans, amphipod tubes, holothurians, shell aggregates) and sedimentary (e.g., sand waves, depressions) structures. Also, removal of organisms that create structures (e.g., crabs, scallops) indirectly reduced complexity. Reductions in habitat complexity may lead to increased predation on juveniles of harvested species and ultimately recruitment to the harvestable stock. Because of a lack of reference sites, where use of mobile fishing is prohibited, no empirical studies have yet been conducted on a scale that could demonstrate population level effects of habitat-management options. If marine fisheries management is to evolve toward an ecosystem or habitat management approach, experiments are required on the effects of habitat change, both anthropogenic and natural.

  3. The impacts of mobile fishing gear on seafloor habitats in the Gulf of Maine (Northwest Atlantic): implications for conservation of fish populations

    USGS Publications Warehouse

    Auster, Peter J.; Malatesta, Richard J.; Langton, Richard W.; Watting, Les; Valentine, Page C.; Donaldson, Carol Lee S.; Langton, Elizabeth W.; Shepard, Andrew N.; Babb, War G.

    1997-01-01

    Fishing gear alters seafloor habitats, but the extent of these alterations, and their effects, have not been quantified extensively in the northwest Atlantic. Understanding the extent of these impacts, and their effects on populations of living marine resources, is needed to properly manage current and future levels of fishing effort and fishing power. For example, the entire U.S. side of the Gulf of Maine was impacted annually by mobile fishing gear between 1984 and 1990, based on calculations of area swept by trawl and dredge gear. Georges Bank was imparted three to nearly four times annually during the same period. Studies at three sites in the Gulf of Maine (off Swans Island, Jeffreys Bank, and Stellwagen Bank) showed that mobile fishing gear altered the physical structure (=complexity) of benthic habitats. Complexity was reduced by direct removal of biogenic (e.g., sponges, hydrozoans, bryozoans, amphipod tubes, holothurians, shell aggregates) and‐ sedimentary (e.g., sand waves, depressions) structures. Also, removal of organisms that create.structures (e.g., crabs, scallops) indirectly reduced complexity. Reductions in habitat complexity may lead to increased predation on juveniles of harvested species and ultimately recruitment to the harvestable stock. Because of a lack of reference sites, where use of mobile fishing is prohibited, no empirical studies have yet been conducted on a scale that could demonstrate population level effects of habitat‐management options. If marine fisheries management is to evolve toward an ecosystem or habitat management approach, experiments are required on the effects of habitat change, both anthropogenic and natural.

  4. Intersex in fishes and amphibians: population implications, prevalence, mechanisms and molecular biomarkers.

    PubMed

    Abdel-Moneim, Ahmed; Coulter, David P; Mahapatra, Cecon T; Sepúlveda, Maria S

    2015-11-01

    Intersex is defined as the abnormal presence of both testicular and ovarian cells in gonads of gonochoristic animals. Its occurrence is widespread and reports on its presence in the gonads of vertebrates continues to increase. In this review, we use standardized terminology to summarize the current knowledge of intersex in gonochoristic fishes and amphibians. We describe the different indices that have been used to assess the severity of intersex and synthesize reports discussing the prevalence of intersex in relation to different types of pollutants. In addition, we evaluate the geographic distribution and chronology of the reported cases of intersex in fishes and amphibians, their pathological descriptions and severity and discuss species sensitivities. We also summarize molecular biomarkers that have been tested for early detection of intersex in wild populations and highlight additional biomarkers that target molecular pathways involved in gonadal development that require further investigation for use in the diagnosis of intersex. Finally, we discuss the needs for future research in this field. PMID:26211897

  5. Comparison of sampling methodologies and estimation of population parameters for a temporary fish ectoparasite.

    PubMed

    Artim, J M; Sikkel, P C

    2016-08-01

    Characterizing spatio-temporal variation in the density of organisms in a community is a crucial part of ecological study. However, doing so for small, motile, cryptic species presents multiple challenges, especially where multiple life history stages are involved. Gnathiid isopods are ecologically important marine ectoparasites, micropredators that live in substrate for most of their lives, emerging only once during each juvenile stage to feed on fish blood. Many gnathiid species are nocturnal and most have distinct substrate preferences. Studies of gnathiid use of habitat, exploitation of hosts, and population dynamics have used various trap designs to estimate rates of gnathiid emergence, study sensory ecology, and identify host susceptibility. In the studies reported here, we compare and contrast the performance of emergence, fish-baited and light trap designs, outline the key features of these traps, and determine some life cycle parameters derived from trap counts for the Eastern Caribbean coral-reef gnathiid, Gnathia marleyi. We also used counts from large emergence traps and light traps to estimate additional life cycle parameters, emergence rates, and total gnathiid density on substrate, and to calibrate the light trap design to provide estimates of rate of emergence and total gnathiid density in habitat not amenable to emergence trap deployment. PMID:27330985

  6. Projected risk of population declines for native fish species in the Upper Mississippi River

    USGS Publications Warehouse

    Crimmins, S.M.; Boma, P.; Thogmartin, W.E.

    2015-01-01

    Conservationists are in need of objective metrics for prioritizing the management of habitats. For individual species, the threat of extinction is often used to prioritize what species are in need of conservation action. Using long-term monitoring data, we applied a Bayesian diffusion approximation to estimate quasi-extinction risk for 54 native fish species within six commercial navigation reaches along a 1350-km gradient of the upper Mississippi River system. We found a strong negative linear relationship between quasi-extinction risk and distance upstream. For some species, quasi-extinction estimates ranged from nearly zero in some reaches to one in others, suggesting substantial variability in threats facing individual river reaches. We found no evidence that species traits affected quasi-extinction risk across the entire system. Our results indicate that fishes within the upper Mississippi River system face localized threats that vary across river impact gradients. This suggests that conservation actions should be focused on local habitat scales but should also consider the additive effects on downstream conditions. We also emphasize the need for identification of proximate mechanisms behind observed and predicted population declines, as conservation actions will require mitigation of such mechanisms. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  7. Oceanography and life history predict contrasting genetic population structure in two Antarctic fish species.

    PubMed

    Young, Emma F; Belchier, Mark; Hauser, Lorenz; Horsburgh, Gavin J; Meredith, Michael P; Murphy, Eugene J; Pascoal, Sonia; Rock, Jennifer; Tysklind, Niklas; Carvalho, Gary R

    2015-06-01

    Understanding the key drivers of population connectivity in the marine environment is essential for the effective management of natural resources. Although several different approaches to evaluating connectivity have been used, they are rarely integrated quantitatively. Here, we use a 'seascape genetics' approach, by combining oceanographic modelling and microsatellite analyses, to understand the dominant influences on the population genetic structure of two Antarctic fishes with contrasting life histories, Champsocephalus gunnari and Notothenia rossii. The close accord between the model projections and empirical genetic structure demonstrated that passive dispersal during the planktonic early life stages is the dominant influence on patterns and extent of genetic structuring in both species. The shorter planktonic phase of C. gunnari restricts direct transport of larvae between distant populations, leading to stronger regional differentiation. By contrast, geographic distance did not affect differentiation in N. rossii, whose longer larval period promotes long-distance dispersal. Interannual variability in oceanographic flows strongly influenced the projected genetic structure, suggesting that shifts in circulation patterns due to climate change are likely to impact future genetic connectivity and opportunities for local adaptation, resilience and recovery from perturbations. Further development of realistic climate models is required to fully assess such potential impacts.

  8. Oceanography and life history predict contrasting genetic population structure in two Antarctic fish species

    PubMed Central

    Young, Emma F; Belchier, Mark; Hauser, Lorenz; Horsburgh, Gavin J; Meredith, Michael P; Murphy, Eugene J; Pascoal, Sonia; Rock, Jennifer; Tysklind, Niklas; Carvalho, Gary R

    2015-01-01

    Understanding the key drivers of population connectivity in the marine environment is essential for the effective management of natural resources. Although several different approaches to evaluating connectivity have been used, they are rarely integrated quantitatively. Here, we use a ‘seascape genetics’ approach, by combining oceanographic modelling and microsatellite analyses, to understand the dominant influences on the population genetic structure of two Antarctic fishes with contrasting life histories, Champsocephalus gunnari and Notothenia rossii. The close accord between the model projections and empirical genetic structure demonstrated that passive dispersal during the planktonic early life stages is the dominant influence on patterns and extent of genetic structuring in both species. The shorter planktonic phase of C. gunnari restricts direct transport of larvae between distant populations, leading to stronger regional differentiation. By contrast, geographic distance did not affect differentiation in N. rossii, whose longer larval period promotes long-distance dispersal. Interannual variability in oceanographic flows strongly influenced the projected genetic structure, suggesting that shifts in circulation patterns due to climate change are likely to impact future genetic connectivity and opportunities for local adaptation, resilience and recovery from perturbations. Further development of realistic climate models is required to fully assess such potential impacts. PMID:26029262

  9. Metformin Exposure at Environmentally Relevant Concentrations Causes Potential Endocrine Disruption in Adult Male Fish

    PubMed Central

    Niemuth, Nicholas J; Jordan, Renee; Crago, Jordan; Blanksma, Chad; Johnson, Rodney; Klaper, Rebecca D

    2015-01-01

    Pharmaceuticals and personal care products (PPCPs) are emerging contaminants that have been found ubiquitously in wastewater and surface waters around the world. A major source of these compounds is incomplete metabolism in humans and subsequent excretion in human waste, resulting in discharge into surface waters by wastewater treatment plant (WWTP) effluent. One pharmaceutical found in particularly high abundance in recent WWTP effluent and surface water studies is metformin, one of the world's most widely prescribed antidiabetic drugs. Interactions between insulin signaling and steroidogenesis suggest potential endocrine-disrupting effects of metformin found in the aquatic environment. Adult fathead minnows (Pimephales promelas) were chronically exposed to metformin for 4 wk, at 40 µg/L, a level similar to the average found in WWTP effluent in Milwaukee, Wisconsin, USA. Genetic endpoints related to metabolism and endocrine function as well as reproduction-related endpoints were examined. Metformin treatment induced significant up-regulation of messenger ribonucleic acid (mRNA) encoding the egg-protein vitellogenin in male fish, an indication of endocrine disruption. The present study, the first to study the effects of environmentally relevant metformin exposure in fathead minnows, demonstrates the need for further study of the endocrine-disrupting effects of metformin in aquatic organisms. Environ Toxicol Chem 2014;9999:1–6. © 2014 The Authors. Published by Wiley Periodicals, Inc. on behalf of SETAC. PMID:25358780

  10. Deep sexual dimorphism in adult medaka fish liver highlighted by multi-omic approach

    PubMed Central

    Qiao, Qin; Le Manach, Séverine; Sotton, Benoit; Huet, Hélène; Duvernois-Berthet, Evelyne; Paris, Alain; Duval, Charlotte; Ponger, Loïc; Marie, Arul; Blond, Alain; Mathéron, Lucrèce; Vinh, Joelle; Bolbach, Gérard; Djediat, Chakib; Bernard, Cécile; Edery, Marc; Marie, Benjamin

    2016-01-01

    Sexual dimorphism describes the features that discriminate between the two sexes at various biological levels. Especially, during the reproductive phase, the liver is one of the most sexually dimorphic organs, because of different metabolic demands between the two sexes. The liver is a key organ that plays fundamental roles in various physiological processes, including digestion, energetic metabolism, xenobiotic detoxification, biosynthesis of serum proteins, and also in endocrine or immune response. The sex-dimorphism of the liver is particularly obvious in oviparous animals, as the female liver is the main organ for the synthesis of oocyte constituents. In this work, we are interested in identifying molecular sexual dimorphism in the liver of adult medaka fish and their sex-variation in response to hepatotoxic exposures. By developing an integrative approach combining histology and different high-throughput omic investigations (metabolomics, proteomics and transcriptomics), we were able to globally depict the strong sexual dimorphism that concerns various cellular and molecular processes of hepatocytes comprising protein synthesis, amino acid, lipid and polysaccharide metabolism, along with steroidogenesis and detoxification. The results of this work imply noticeable repercussions on the biology of oviparous organisms environmentally exposed to chemical or toxin issues. PMID:27561897

  11. Radial glia-mediated up-regulation of somatostatin in the regenerating adult fish brain.

    PubMed

    Zupanc, G K; Clint, S C

    2001-08-31

    Adult teleost fish, Apteronotus leptorhynchus, exhibit an enormous regenerative capability after application of mechanical lesions to the dorsalmost subdivision of the cerebellum, the corpus cerebelli. Restoration of the neural tissue is achieved by a cascade of processes, including the guidance of migrating new neurons to the site of injury by radial glial fibers. These fibers are characterised by the expression of immunoreactive glial fibrillary acidic protein and by several morphological features. Within 12 h following the lesion, the fraction of radial glial fibers expressing the neuropeptide somatostatin (SRIF) dramatically increased from approximately 1%, as found in the intact brain, to roughly 27% 12-24 h post-lesion. Subsequently, the percentage of SRIF-expressing radial glial fibers gradually declined, until it reached background levels at about 10 days following the injury. We hypothesise that the expression of SRIF is related to the generation and/or differentiation of the new neurons produced in response to the lesion, rather than to the later guidance of these cells along their migratory pathway.

  12. Deep sexual dimorphism in adult medaka fish liver highlighted by multi-omic approach.

    PubMed

    Qiao, Qin; Le Manach, Séverine; Sotton, Benoit; Huet, Hélène; Duvernois-Berthet, Evelyne; Paris, Alain; Duval, Charlotte; Ponger, Loïc; Marie, Arul; Blond, Alain; Mathéron, Lucrèce; Vinh, Joelle; Bolbach, Gérard; Djediat, Chakib; Bernard, Cécile; Edery, Marc; Marie, Benjamin

    2016-01-01

    Sexual dimorphism describes the features that discriminate between the two sexes at various biological levels. Especially, during the reproductive phase, the liver is one of the most sexually dimorphic organs, because of different metabolic demands between the two sexes. The liver is a key organ that plays fundamental roles in various physiological processes, including digestion, energetic metabolism, xenobiotic detoxification, biosynthesis of serum proteins, and also in endocrine or immune response. The sex-dimorphism of the liver is particularly obvious in oviparous animals, as the female liver is the main organ for the synthesis of oocyte constituents. In this work, we are interested in identifying molecular sexual dimorphism in the liver of adult medaka fish and their sex-variation in response to hepatotoxic exposures. By developing an integrative approach combining histology and different high-throughput omic investigations (metabolomics, proteomics and transcriptomics), we were able to globally depict the strong sexual dimorphism that concerns various cellular and molecular processes of hepatocytes comprising protein synthesis, amino acid, lipid and polysaccharide metabolism, along with steroidogenesis and detoxification. The results of this work imply noticeable repercussions on the biology of oviparous organisms environmentally exposed to chemical or toxin issues. PMID:27561897

  13. Deep sexual dimorphism in adult medaka fish liver highlighted by multi-omic approach.

    PubMed

    Qiao, Qin; Le Manach, Séverine; Sotton, Benoit; Huet, Hélène; Duvernois-Berthet, Evelyne; Paris, Alain; Duval, Charlotte; Ponger, Loïc; Marie, Arul; Blond, Alain; Mathéron, Lucrèce; Vinh, Joelle; Bolbach, Gérard; Djediat, Chakib; Bernard, Cécile; Edery, Marc; Marie, Benjamin

    2016-08-26

    Sexual dimorphism describes the features that discriminate between the two sexes at various biological levels. Especially, during the reproductive phase, the liver is one of the most sexually dimorphic organs, because of different metabolic demands between the two sexes. The liver is a key organ that plays fundamental roles in various physiological processes, including digestion, energetic metabolism, xenobiotic detoxification, biosynthesis of serum proteins, and also in endocrine or immune response. The sex-dimorphism of the liver is particularly obvious in oviparous animals, as the female liver is the main organ for the synthesis of oocyte constituents. In this work, we are interested in identifying molecular sexual dimorphism in the liver of adult medaka fish and their sex-variation in response to hepatotoxic exposures. By developing an integrative approach combining histology and different high-throughput omic investigations (metabolomics, proteomics and transcriptomics), we were able to globally depict the strong sexual dimorphism that concerns various cellular and molecular processes of hepatocytes comprising protein synthesis, amino acid, lipid and polysaccharide metabolism, along with steroidogenesis and detoxification. The results of this work imply noticeable repercussions on the biology of oviparous organisms environmentally exposed to chemical or toxin issues.

  14. Evaluation of marine subareas of Europe using life history parameters and trophic levels of selected fish populations.

    PubMed

    Jayasinghe, R P Prabath K; Amarasinghe, Upali S; Newton, Alice

    2015-12-01

    European marine waters include four regional seas that provide valuable ecosystem services to humans, including fish and other seafood. However, these marine environments are threatened by pressures from multiple anthropogenic activities and climate change. The European Marine Strategy Framework Directive (MSFD) was adopted in 2008 to achieve good environmental status (GEnS) in European Seas by year 2020, using an Ecosystem Approach. GEnS is to be assessed using 11 descriptors and up to 56 indicators. In the present analysis two descriptors namely "commercially exploited fish and shellfish populations" and "food webs" were used to evaluate the status of subareas of FAO 27 area. Data on life history parameters, trophic levels and fisheries related data of cod, haddock, saithe, herring, plaice, whiting, hake and sprat were obtained from the FishBase online database and advisory reports of International Council for the Exploration of the Sea (ICES). Subareas inhabited by r and K strategists were identified using interrelationships of life history parameters of commercially important fish stocks. Mean trophic level (MTL) of fish community each subarea was calculated and subareas with species of high and low trophic level were identified. The Fish in Balance (FiB) index was computed for each subarea and recent trends of FiB indices were analysed. The overall environmental status of each subarea was evaluated considering life history trends, MTL and FiB Index. The analysis showed that subareas I, II, V, VIII and IX were assessed as "good" whereas subareas III, IV, VI and VII were assessed as "poor". The subareas assessed as "good" were subject to lower environmental pressures, (less fishing pressure, less eutrophication and more water circulation), while the areas with "poor" environment experienced excessive fishing pressure, eutrophication and disturbed seabed. The evaluation was based on two qualitative descriptors ("commercially exploited fish and shellfish

  15. Potential population and assemblage influences of non-native trout on native nongame fish in Nebraska headwater streams

    USGS Publications Warehouse

    Turek, Kelly C.; Pegg, Mark A.; Pope, Kevin L.; Schainost, Steve

    2014-01-01

    Non-native trout are currently stocked to support recreational fisheries in headwater streams throughout Nebraska. The influence of non-native trout introductions on native fish populations and their role in structuring fish assemblages in these systems is unknown. The objectives of this study were to determine (i) if the size structure or relative abundance of native fish differs in the presence and absence of non-native trout, (ii) if native fish-assemblage structure differs in the presence and absence of non-native trout and (iii) if native fish-assemblage structure differs across a gradient in abundances of non-native trout. Longnose dace Rhinichthys cataractae were larger in the presence of brown trout Salmo trutta and smaller in the presence of rainbow trout Oncorhynchus mykiss compared to sites without trout. There was also a greater proportion of larger white suckers Catostomus commersonii in the presence of brown trout. Creek chub Semotilus atromaculatus and fathead minnow Pimephales promelas size structures were similar in the presence and absence of trout. Relative abundances of longnose dace, white sucker, creek chub and fathead minnow were similar in the presence and absence of trout, but there was greater distinction in native fish-assemblage structure between sites with trout compared to sites without trout as trout abundances increased. These results suggest increased risk to native fish assemblages in sites with high abundances of trout. However, more research is needed to determine the role of non-native trout in structuring native fish assemblages in streams, and the mechanisms through which introduced trout may influence native fish populations.

  16. Evaluation of marine subareas of Europe using life history parameters and trophic levels of selected fish populations.

    PubMed

    Jayasinghe, R P Prabath K; Amarasinghe, Upali S; Newton, Alice

    2015-12-01

    European marine waters include four regional seas that provide valuable ecosystem services to humans, including fish and other seafood. However, these marine environments are threatened by pressures from multiple anthropogenic activities and climate change. The European Marine Strategy Framework Directive (MSFD) was adopted in 2008 to achieve good environmental status (GEnS) in European Seas by year 2020, using an Ecosystem Approach. GEnS is to be assessed using 11 descriptors and up to 56 indicators. In the present analysis two descriptors namely "commercially exploited fish and shellfish populations" and "food webs" were used to evaluate the status of subareas of FAO 27 area. Data on life history parameters, trophic levels and fisheries related data of cod, haddock, saithe, herring, plaice, whiting, hake and sprat were obtained from the FishBase online database and advisory reports of International Council for the Exploration of the Sea (ICES). Subareas inhabited by r and K strategists were identified using interrelationships of life history parameters of commercially important fish stocks. Mean trophic level (MTL) of fish community each subarea was calculated and subareas with species of high and low trophic level were identified. The Fish in Balance (FiB) index was computed for each subarea and recent trends of FiB indices were analysed. The overall environmental status of each subarea was evaluated considering life history trends, MTL and FiB Index. The analysis showed that subareas I, II, V, VIII and IX were assessed as "good" whereas subareas III, IV, VI and VII were assessed as "poor". The subareas assessed as "good" were subject to lower environmental pressures, (less fishing pressure, less eutrophication and more water circulation), while the areas with "poor" environment experienced excessive fishing pressure, eutrophication and disturbed seabed. The evaluation was based on two qualitative descriptors ("commercially exploited fish and shellfish

  17. Population correlates of circulating mercury levels in Korean adults: the Korea National Health and Nutrition Examination Survey IV

    PubMed Central

    2014-01-01

    Background Prior studies focused on bioaccumulation of mercury (Hg) and on large, long-lived fish species as the major environmental source of Hg, but little is known about consumption of small-sized fish or about non-dietary determinants of circulating Hg levels. The purpose of this study was to evaluate whole blood mercury concentration (WBHg) and its major dietary and non-dietary correlates in Korean adults. Methods We analyzed cross-sectional data from 3,972 (male = 1,994; female = 1,978) participants who completed the Korean National Health and Nutrition Examination Survey IV, 2008 to 2009. Relevant factors included diet, geographic location of residence, demographics, and lifestyle. WBHg concentration was measured using cold-vapor atomic absorption spectrometry. Multivariable linear models assessed independent correlates of dietary and non-dietary factors for WBHg levels. Results Median levels of WBHg were 5.1 μg/L in men and 3.7 μg/L in women. Higher levels of fish/shellfish intake were associated with higher levels of WBHg. Higher consumption of small-sized fish was linked to higher levels of WBHg. Non-dietary predictors of higher WBHg were being male, greater alcohol consumption, higher income and education, overweight/obesity, increasing age, and living in the southeast region. Conclusions Both dietary and non-dietary factors were associated with WBHg levels in the Korean population. There is significant geographic variation in WBHg levels; residents living in the mid-south have higher WBHg levels. We speculate that uncontrolled geographic characteristics, such as local soil/water content and specific dietary habits are involved. PMID:24884916

  18. ShapeR: An R Package to Study Otolith Shape Variation among Fish Populations

    PubMed Central

    Libungan, Lísa Anne; Pálsson, Snæbjörn

    2015-01-01

    ShapeR is an open source software package that runs on the R platform and is specifically designed to study otolith shape variation among fish populations. The package extends previously described software used for otolith shape analysis by allowing the user to automatically extract closed contour outlines from a large number of images, perform smoothing to eliminate pixel noise, choose from conducting either a Fourier or Wavelet transform to the outlines and visualize the mean shape. The output of the package are independent Fourier or Wavelet coefficients which can be directly imported into a wide range of statistical packages in R. The package might prove useful in studies of any two dimensional objects. PMID:25803855

  19. Lack of population genetic differentiation of a marine ovoviviparous fish Sebastes schlegelii in Northwestern Pacific.

    PubMed

    Zhang, Hui; Yanagimoto, Takashi; Zhang, Xiumei; Song, Na; Gao, Tianxiang

    2016-05-01

    Sebastes schlegelii is one of the fishes that aggregate around drifting seaweed during early development. To examine the population genetic structure of S. schlegelii, a 452-bp fragment of the mtDNA control region was sequenced and used to interpret life history characteristics and larval dispersal strategy. Two-hundred and twenty-one individuals from 13 sites across the entire range of S. schlegelii in China, Japan and Korea were analyzed. A neighbor-joining tree and network showed that there were no significant genealogical structures corresponding to sampling locations. AMOVA, pair-wise FST and exact test revealed no significant genetic differentiation among locations. The migration rate among locations was high based on the result of LAMARC. We conclude that larval dispersal with drifting seaweed and the current environmental factors may play an important role in shaping the contemporary phylogeographic pattern and genetic homogeneity of S. schlegelii.

  20. Well-Being in an Adult Swedish Population

    ERIC Educational Resources Information Center

    Hansson, Anna; Hilleras, Pernilla; Forsell, Yvonne

    2005-01-01

    Objectives: The aim of this study was to see if earlier findings about factors associated with well-being could be replicated in a large population-based sample in Sweden. To the best of our knowledge, no research on well-being has been conducted on such a large population in a country, which by most standards is regarded as one of the most…

  1. Dissociative Symptoms and Mother's Marital Status in Young Adult Population

    PubMed Central

    Bob, Petr; Selesova, Petra; Raboch, Jiri; Kukla, Lubomir

    2015-01-01

    Abstract Current findings suggest that mother's marital status indicating father's absence or conflicting relationship to father may be specifically related to dissociation and other stress-related symptoms. We have assessed relationships of mother's marital status, dissociative symptoms, and other psychopathological manifestations in a sample of 19 years’ old young adults (N = 364) participating in European longitudinal study (European Longitudinal Study of Parenthood and Childhood). The results show clinically significant manifestations of dissociative symptoms in young adult men whose mothers were fatherless and in women whose mothers were re-married. Other psychopathological symptoms did not reach clinically significant manifestations. The results suggest that significant factor related to high level of dissociative symptoms in men growing in fatherless families might be linked with disturbed and conflicting attachment to a father's figure and pathological dependent attachment to mother. In women dissociative symptoms likely are linked to conflicting relationship between mother and daughter associated with stepfather’ presence in the family. PMID:25590849

  2. Use of population viability analysis to evaluate CITES trade-management options for threatened marine fishes.

    PubMed

    Curtis, Janelle M R; Vincent, Amanda C J

    2008-10-01

    Achieving multiple conservation objectives can be challenging, particularly under high uncertainty. Having agreed to limit seahorse (Hippocampus) exports to sustainable levels, signatories to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) were offered the option of a single 10-cm minimum size limit (MSL) as an interim management measure for all Hippocampus species (> or =34). Although diverse stakeholders supported the recommended MSL, its biological and socioeconomic implications were not assessed quantitatively. We combined population viability analysis, model sensitivity analysis, and economic information to evaluate the trade-off between conservation threat to and long-term cumulative income from these exploited marine fishes of high conservation concern. We used the European long-snouted seahorse (Hippocampus guttulatus) as a representative species to compare the performance of MSLs set at alternative biological reference points. Our sensitivity analyses showed that in most of our scenarios, setting the MSL just above size at maturity (9.7 cm in H. guttulatus) would not prevent exploited populations from becoming listed as vulnerable. By contrast, the relative risk of decline and extinction were almost halved--at a cost of only a 5.6% reduction in long-term catches--by increasing the MSL to the size reached after at least one full reproductive season. On the basis of our analysis, a precautionary increase in the MSL could be compatible with sustaining fishers' livelihoods and international trade. Such management tactics that aid species conservation and have minimal effects on long term catch trends may help bolster the case for CITES trade management of other valuable marine fishes.

  3. Optimising inhaled mannitol for cystic fibrosis in an adult population

    PubMed Central

    Flume, Patrick A.; Aitken, Moira L.; Agent, Penny; Charlton, Brett; Forster, Emma; Fox, Howard G.; Hebestreit, Helge; Kolbe, John; Zuckerman, Jonathan B; Button, Brenda M.

    2015-01-01

    Abstract There has been remarkable progress in the treatment of cystic fibrosis (CF) patients over the past 20 years. However, limitations of standard therapies have highlighted the need for a convenient alternative treatment to effectively target the pathophysiologic basis of CF-related disease by improving mucociliary clearance of airway secretions and consequently improve lung function and reduce respiratory exacerbations. Mannitol is an osmotic agent available as a dry powder, dispensed in a convenient disposable inhaler device for the treatment of adult patients with CF. Inhalation of mannitol as a dry powder is thought to change the viscoelastic properties of airway secretions, increase the hydration of the airway surface liquid and contribute to increased mucociliary and cough clearance of retained secretions. In two large phase 3 studies [1, 2], long-term use of inhaled mannitol resulted in a significant and clinically meaningful improvement in lung function relative to control in adult CF subjects and had an acceptable safety profile. Clinical experience with inhaled mannitol confirms that it is safe and effective. A minority of patients are unable to tolerate the medication. However, through training in proper inhaler technique and setting clear expectations regarding therapeutic effects, both the tolerance and adherence necessary for long term efficacy can be positively influenced. Educational aims To discuss the importance of airway clearance treatments in the management of cystic fibrosis. To describe the clinical data that supports the use of mannitol in adult patients with cystic fibrosis. To highlight the role of mannitol tolerance testing in screening for hyperresponsiveness. To provide practical considerations for patient education in use of mannitol inhaler. Key points Inhaled mannitol is a safe and effective option in adult patients with cystic fibrosis. Mannitol tolerance testing effectively screens for hyperresponsiveness prior to initiation

  4. Grammatical Class Effects Across Impaired Child and Adult Populations.

    PubMed

    Kambanaros, Maria; Grohmann, Kleanthes K

    2015-01-01

    The aims of this study are to compare quantitative and qualitative differences for noun/verb retrieval across language-impaired groups, examine naming errors with reference to psycholinguistic models of word processing, and shed light on the nature of the naming deficit as well as determine relevant group commonalities and differences. This includes an attempt to establish whether error types differentiate language-impaired children from adults, to determine effects of psycholinguistic variables on naming accuracies, and to link the results to genetic mechanisms and/or neural circuitry in the brain. A total of 89 (language-)impaired participants took part in this report: 24 adults with acquired aphasia, 20 adults with schizophrenia-spectrum disorder, 31 adults with relapsing-remitting multiple sclerosis, and 14 children with specific language impairment. The results of simultaneous multiple regression analyses for the errors in verb naming compared to the psycholinguistic variables for all language-impaired groups are reported and discussed in relation to models of lexical processing. This discussion will lead to considerations of genetic and/or neurobiological underpinnings: Presence of the noun-verb dissociation in focal and non-focal brain impairment make localization theories redundant, but support for wider neural network involvement.The patterns reported cannot be reduced to any one level of language processing, suggesting multiple interactions at different levels (e.g., receptive vs. expressive language abilities).Semantic-conceptual properties constrain syntactic properties with implications for phonological word form retrieval.Competition needs to be resolved at both conceptual and phonological levels of representation. Moreover, this study may provide a cross-pathological baseline that can be probed further with respect to recent suggestions concerning a reconsideration of open- vs. closed-class items, according to which verbs may actually fall into the

  5. Grammatical Class Effects Across Impaired Child and Adult Populations

    PubMed Central

    Kambanaros, Maria; Grohmann, Kleanthes K.

    2015-01-01

    The aims of this study are to compare quantitative and qualitative differences for noun/verb retrieval across language-impaired groups, examine naming errors with reference to psycholinguistic models of word processing, and shed light on the nature of the naming deficit as well as determine relevant group commonalities and differences. This includes an attempt to establish whether error types differentiate language-impaired children from adults, to determine effects of psycholinguistic variables on naming accuracies, and to link the results to genetic mechanisms and/or neural circuitry in the brain. A total of 89 (language-)impaired participants took part in this report: 24 adults with acquired aphasia, 20 adults with schizophrenia-spectrum disorder, 31 adults with relapsing-remitting multiple sclerosis, and 14 children with specific language impairment. The results of simultaneous multiple regression analyses for the errors in verb naming compared to the psycholinguistic variables for all language-impaired groups are reported and discussed in relation to models of lexical processing. This discussion will lead to considerations of genetic and/or neurobiological underpinnings: Presence of the noun–verb dissociation in focal and non-focal brain impairment make localization theories redundant, but support for wider neural network involvement.The patterns reported cannot be reduced to any one level of language processing, suggesting multiple interactions at different levels (e.g., receptive vs. expressive language abilities).Semantic-conceptual properties constrain syntactic properties with implications for phonological word form retrieval.Competition needs to be resolved at both conceptual and phonological levels of representation. Moreover, this study may provide a cross-pathological baseline that can be probed further with respect to recent suggestions concerning a reconsideration of open- vs. closed-class items, according to which verbs may actually fall into the

  6. Power to Detect Trends in Missouri River Fish Populations within the Habitat Assessment Monitoring Program

    USGS Publications Warehouse

    Bryan, Janice L.; Wildhaber, Mark L.; Gladish, Dan W.

    2010-01-01

    As with all large rivers in the United States, the Missouri River has been altered, with approximately one-third of the mainstem length impounded and one-third channelized. These physical alterations to the environment have affected the fish populations, but studies examining the effects of alterations have been localized and for short periods of time, thereby preventing generalization. In response to the U.S. Fish and Wildlife Service Biological Opinion, the U.S. Army Corps of Engineers (USACE) initiated monitoring of habitat improvements of the Missouri River in 2005. The goal of the Habitat Assessment Monitoring Program (HAMP) is to provide information on the response of target fish species to the USACE habitat creation on the Lower Missouri River. To determine the statistical power of the HAMP and in cooperation with USACE, a power analysis was conducted using a normal linear mixed model with variance component estimates based on the first complete year of data. At a level of 20/16 (20 bends with 16 subsamples in each bend), at least one species/month/gear model has the power to determine differences between treated and untreated bends. The trammel net in September had the most species models with adequate power at the 20/16 level and overall, the trammel net had the most species/month models with adequate power at the 20/16 level. However, using only one gear or gear/month combination would eliminate other species of interest, such as three chub species (Macrhybopsis meeki, Macrhybopsis aestivalis, and Macrhybopsis gelida), sand shiners (Notropis stramineus), pallid sturgeon (Scaphirhynchus albus), and juvenile sauger (Sander canadensis). Since gear types are selective in their species efficiency, the strength of the HAMP approach is using multiple gears that have statistical power to differentiate habitat treatment differences in different fish species within the Missouri River. As is often the case with sampling rare species like the pallid sturgeon, the

  7. Larvae and adults of Hysterothylacium aduncum (Rudolphi, 1802) (Nematoda: Anisakidae) in fishes and crustaceans in the south west Atlantic.

    PubMed

    Navone, G T; Sardella, N H; Timi, J T

    1998-06-01

    Hysterothylacium aduncum (Rudolphi, 1802) is reported from five fishes and one invertebrate species. Third-stage larvae were found in the crustacean Themisto gaudichaudii and in mesenteries of the fishes Engraulis anchoita and Merluccius hubbsi; fourth-stage larvae were recovered from the digestive tract of M. hubbsi and Scomber japonicus and adult specimens were obtained from the stomach and intestine of M. hubbsi, S. japonicus, Genypterus blacodes and Genypterus brasiliensis. Nematodes are described, measured and illustrated. Parasitic prevalence, mean intensity and range were calculated in relation to different geographic zones, from the Argentinean-Uruguayan Common Fishing Zone to Patagonic areas. An increase of parasitism from the northern areas southwards was observed. The life-cycle of H. aduncum, involving the host species considered, is also postulated. PMID:9754308

  8. Only a small population of adult Sertoli cells actively proliferates in culture.

    PubMed

    Kulibin, Andrey Yu; Malolina, Ekaterina A

    2016-10-01

    Adult mammalian Sertoli cells (SCs) have been considered to be quiescent terminal differentiated cells for many years, but recently, proliferation of adult SCs was demonstrated in vitro and in vivo We further examined mouse SC behavior in culture and found that there are two populations of adult SCs. The first population is SCs from seminiferous tubules that hardly proliferate in vitro The second population is small and consists of SCs with atypical nuclear morphology from the terminal segments of seminiferous tubules, a transitional zone (TZ). TZ SCs multiply in culture and form colonies, display mixture of mature and immature SC characteristics, and generate cord-like structures in a collagen matrix. The specific features of TZ SCs are ACTA2 expression in vitro and DMRT1 low levels in vivo and in vitro Although the in vivo function of TZ SCs still remains unclear, this finding has significant implications for our understanding of SC differentiation and functioning in adult mammals.

  9. Strong positive associations between seafood, vegetables, and alcohol with blood mercury and urinary arsenic levels in the Korean adult population.

    PubMed

    Park, Sunmin; Lee, Byung-Kook

    2013-01-01

    Blood mercury and urinary arsenic levels are more than fivefold greater in the Korean population compared with those of the United States. This may be related to the foods people consumed. Therefore, we examined the associations between food categories and mercury and arsenic exposure in the Korean adult population. Data regarding nutritional, biochemical, and health-related parameters were obtained from a cross-sectional study, the 2008-2009 Korean National Health and Nutrition Examination Survey (3,404 men and women age ≥ 20 years). The log-transformed blood mercury and urinary arsenic levels were regressed against the frequency tertiles of each food group after covariate adjustment for sex, age, residence area, education level, smoking status, and drinking status using food-frequency data. Blood mercury levels in the high consumption groups compared to the low consumption groups were elevated by about 20 percents with salted fish, shellfish, whitefish, bluefish, and alcohol, and by about 9-14 percents with seaweeds, green vegetables, fruits and tea, whereas rice did not affect blood mercury levels. Urinary arsenic levels were markedly increased with consumption of rice, bluefish, salted fish, shellfish, whitefish, and seaweed, whereas they were moderately increased with consumption of grains, green and white vegetables, fruits, coffee, and alcohol. The remaining food categories tended to lower these levels only minimally. In conclusion, the typical Asian diet, which is high in rice, salted fish, shellfish, vegetables, alcoholic beverages, and tea, may be associated with greater blood mercury and urinary arsenic levels. This study suggests that mercury and arsenic contents should be monitored and controlled in soil and water used for agriculture to decrease health risks from heavy-metal contamination. PMID:23011092

  10. Persistence of an extreme male-biased adult sex ratio in a natural population of polyandrous bird.

    PubMed

    Kosztolányi, A; Barta, Z; Küpper, C; Székely, T

    2011-08-01

    In a number of insects, fishes and birds, the conventional sex roles are reversed: males are the main care provider, whereas females focus on matings. The reversal of typical sex roles is an evolutionary puzzle, because it challenges the foundations of sex roles, sexual selection and parental investment theory. Recent theoretical models predict that biased parental care may be a response to biased adult sex ratios (ASRs). However, estimating ASR is challenging in natural populations, because males and females often have different detectabilities. Here, we use demographic modelling with field data from 2101 individuals, including 579 molecularly sexed offspring, to provide evidence that ASR is strongly male biased in a polyandrous bird with male-biased care. The model predicts 6.1 times more adult males than females (ASR=0.860, proportion of males) in the Kentish plover Charadrius alexandrinus. The extreme male bias is consistent between years and concordant with experimental results showing strongly biased mating opportunity towards females. Based on these results, we conjecture that parental sex-role reversal may occur in populations that exhibit extreme male-biased ASR.

  11. Diverse juvenile life-history behaviours contribute to the spawning stock of an anadromous fish population

    USGS Publications Warehouse

    Walsworth, Timothy E.; Schindler, Daniel E.; Griffiths, Jennifer R.; Zimmerman, Christian E.

    2015-01-01

    Habitat quality often varies substantially across space and time, producing a shifting mosaic of growth and mortality trade-offs across watersheds. Traditional studies of juvenile habitat use have emphasised the evolution of single optimal strategies that maximise recruitment to adulthood and eventual fitness. However, linking the distribution of individual behaviours that contribute to recruitment at the population level has been elusive, particularly for highly fecund aquatic organisms. We examined juvenile habitat use within a population of sockeye salmon (Oncorhynchus nerka) that spawn in a watershed consisting of two interconnected lakes and a marine lagoon. Otolith microchemical analysis revealed that the productive headwater lake accounted for about half of juvenile growth for those individuals surviving to spawn in a single river in the upper watershed. However, 47% of adults had achieved more than half of their juvenile growth in the downstream less productive lake, and 3% of individuals migrated to the estuarine environment during their first summer and returned to freshwater to overwinter before migrating back to sea. These results describe a diversity of viable habitat-use strategies by juvenile sockeye salmon that may buffer the population against poor conditions in any single rearing environment, reduce density-dependent mortality and have implications for the designation of critical habitat for conservation purposes. A network of accessible alternative habitats providing trade-offs in growth and survival may be important for long-term viability of populations.

  12. Novel estimates of Aedes aegypti (Diptera: Culicidae) population size and adult survival based on Wolbachia releases.

    PubMed

    Ritchie, Scott A; Montgomery, Brian L; Hoffmann, Ary A

    2013-05-01

    The size of Aedes aegypti (L.) mosquito populations and adult survival rates have proven difficult to estimate because of a lack of consistent quantitative measures to equate sampling methods, such as adult trapping, to actual population size. However, such estimates are critical for devising control methods and for modeling the transmission of dengue and other infectious agents carried by this species. Here we take advantage of recent releases of Wolbachia-infected Ae. aegypti coupled with the results of ongoing monitoring to estimate the size of adult Ae. aegypti populations around Cairns in far north Queensland, Australia. Based on the association between released adults infected with Wolbachia and data from Biogents Sentinel traps, we show that data from two locations are consistent with population estimates of approximately 5-10 females per house and daily survival rates of 0.7-0.9 for the released Wolbachia-infected females. Moreover, we estimate that networks of Biogents Sentinel traps at a density of one per 15 houses capture around 5-10% of the adult population per week, and provide a rapid estimate of the absolute population size of Ae. aegypti. These data are discussed with respect to release rates and monitoring in future Wolbachia releases and also the levels of suppression required to reduce dengue transmission. PMID:23802459

  13. Dietary patterns are associated with cardiometabolic risk factors in a representative study population of German adults.

    PubMed

    Heidemann, Christin; Scheidt-Nave, Christa; Richter, Almut; Mensink, Gert B M

    2011-10-01

    Studies that investigated complex actual eating behaviours of the general population and their relation to cardiometabolic risk markers are sparse. We aimed to identify dietary patterns within a nationally representative sample of 4025 German adults by factor analysis based on validated dietary history interviews. Furthermore, we evaluated associations of the derived dietary patterns with abnormalities clustered within the metabolic syndrome and related metabolic markers by logistic regression models and ANCOVA. A high adherence to the 'processed foods' pattern reflected a high intake of refined grains, processed meat, red meat, high-sugar beverages, eggs, potatoes, beer, sweets and cakes, snacks and butter, whereas a high adherence to the 'health-conscious' pattern represented a high intake of vegetables, vegetable oils, legumes, fruits, fish and whole grains. For subjects in the highest compared with those in the lowest quintile of the processed foods pattern, the occurrence of abdominal obesity was 88 (95 % CI 31, 169) % higher, hypertension was 34 (95 % CI - 4, 86) % higher, hypertriacylglycerolaemia was 59 (95 % CI 11, 128 ) % higher and the metabolic syndrome was 64 (95 % CI 10, 143) % higher when adjusted for age, sex, energy intake, socio-economic status, sport activity and smoking. Furthermore, subjects in the highest quintile had statistically significantly higher uric acid concentrations and lower folate concentrations (P for trend < 0·05). In contrast, subjects in the highest quintile of the health-conscious pattern had a 30 (95 % CI 10, 46) % lower occurrence of hypertension, higher folate concentrations and lower homocysteine and fibrinogen concentrations (P for trend < 0·05). These data strengthen the findings from non-representative studies and emphasise the importance of healthy overall food patterns for preventing metabolic disturbances. PMID:21736839

  14. Assessing impacts of land-applied manure from concentrated animal feeding operations on fish populations and communities.

    PubMed

    Leet, Jessica K; Lee, Linda S; Gall, Heather E; Goforth, Reuben R; Sassman, Stephen; Gordon, Denise A; Lazorchak, James M; Smith, Mark E; Jafvert, Chad T; Javfert, Chad T; Sepúlveda, Maria S

    2012-12-18

    Concentrated animal feeding operation (CAFO) manure is a cost-effective fertilizer. In the Midwest, networks of subsurface tile-drains expedite transport of animal hormones and nutrients from land-applied CAFO manure to adjacent waterways. The objective of this study was to evaluate impacts of land-applied CAFO manure on fish populations and communities. Water chemistry including hormone, pesticide, and nutrient concentrations was characterized from study sites along with fish assemblage structure, growth, and endocrine disruption assessed in selected fish species. Although most CAFO water samples had hormone concentrations <1 ng/L, equivalent concentrations for 17β-E2 and 17α-TB peaked at >30 ng/L each during the period of spawning, hatching, and development for resident fishes. CAFO sites had lower fish species richness, and fishes exhibited faster somatic growth and lower reproductive condition compared to individuals from the reference site. Fathead minnows (Pimephales promelas) exposed to CAFO ditchwater during early developmental stages exhibited significantly skewed sex ratios toward males. Maximum observed hormone concentrations were well above the lowest observable effect concentrations for these hormones; however, complexities at the field scale make it difficult to directly relate hormone concentration and impacts on fish. Complicating factors include the consistent presence of pesticides and nutrients, and the difference in temperature and stream architecture of the CAFO-impacted ditches compared to the reference site (e.g., channelization, bottom substrate, shallow pools, and riparian cover). PMID:23171355

  15. Understanding the determinate-indeterminate fecundity dichotomy in fish populations using a temperature dependent oocyte growth model

    NASA Astrophysics Data System (ADS)

    Ganias, Kostas; Lowerre-Barbieri, Susan K.; Cooper, Wade

    2015-02-01

    The fecundity type (determinate vs. indeterminate) is still uncertain for many commercially important fish populations affecting accuracy in fecundity estimations and hindering the selection of appropriate egg production methods for stock assessment purposes. It is broadly considered that boreal fish populations living in colder habitats are determinate spawners whilst populations residing in warmer habitats tend to be indeterminate spawners. In the present study we modelled the determinate-indeterminate fecundity type in batch spawning fishes, i.e. fish that spawn several batches of eggs per spawning season, based on the relationship between oocyte growth period and the duration of the spawning period considering that both variables can be affected by water temperature and latitudinal distributions. Individual based models (IBMs) were developed to explore how the interaction of these variables can result in a series of patterns along the continuum from extreme determinacy, i.e. annual fecundity being recruited long before the onset of the spawning period, to indeterminacy. Model simulations showed that fish stocks with oocyte growth periods longer than the spawning period are predicted to exhibit determinate fecundity which provides a fair justification for why cold water species with slow oocyte growth and limited spawning periods are determinate spawners and vice versa.

  16. Assessing the health of fish populations in the Clinch River system: Application of multi-response bioindicators

    SciTech Connect

    Adams, M.; Greeley, M.; LeHew, R.; Ham, K.; Bevelhimer, M.

    1995-12-31

    As a component of the Clinch River Remedial Investigation Project, multi-response bioindicators have been used as integrative and holistic measures of fish population and community health. The integrated bioindicator approach involves measuring a suite of selected indicators at several levels of biological organization from the biomolecular to the community levels. Multi-response indicators of stress at several levels of biological organization provides insights into causal mechanisms between contaminant exposure and population-level effects and provides a basis for which the effectiveness of future remedial actions on fish population health can be evaluated. Bioindicator responses were grouped into six functional categories representing indicators of (1) contaminant exposure (detoxification enzymes), (2) organ dysfunction, (3) histopathology, (4) overall fish health (condition indices), (5) feeding and nutritional status, and (6) fish community integrity. Detoxification enzyme induction, histopathological effects, reproductive dysfunction, bioenergetic impairment, and reduced fish community diversity was observed at several sample sites in the Clinch River System. When all the bioindicators were evaluated together in a canonical variate analysis procedure, the integrated site responses segregated clearly into contaminant affected sites and reference areas. Most of these effects appear to be related to the downstream gradient in contaminant loading from the Oak Ridge Reservation and to the pattern of specific PCB congeners occurring at these sites.

  17. Adult hippocampal neurogenesis in natural populations of mammals.

    PubMed

    Amrein, Irmgard

    2015-05-01

    This review will discuss adult hippocampal neurogenesis in wild mammals of different taxa and outline similarities with and differences from laboratory animals. It begins with a review of evidence for hippocampal neurogenesis in various mammals, and shows the similar patterns of age-dependent decline in cell proliferation in wild and domesticated mammals. In contrast, the pool of immature neurons that originate from proliferative activity varies between species, implying a selective advantage for mammals that can make use of a large number of these functionally special neurons. Furthermore, rapid adaptation of hippocampal neurogenesis to experimental challenges appears to be a characteristic of laboratory rodents. Wild mammals show species-specific, rather stable hippocampal neurogenesis, which appears related to demands that characterize the niche exploited by a species rather than to acute events in the life of its members. Studies that investigate adult neurogenesis in wild mammals are not numerous, but the findings of neurogenesis under natural conditions can provide new insights, and thereby also address the question to which cognitive demands neurogenesis may respond during selection.

  18. Reduced productivity in adult yellowfever mosquito (Diptera: Culicidae) populations

    SciTech Connect

    Rodriguez, P.H.; Hamm, W.J.; Garcia, F.; Garcia, M.; Schirf, V.

    1989-04-01

    Male and female Aedes aegypti (L.) mosquitoes of the laboratory strain ROCK were irradiated with 130 mw of argon 514.5 nm laser microbeams for 0.04, 0.25, 0.4, and 0.5 s, respectively. Egg production, percentage hatch, and productivity (average number of adults surviving after 3 wk) were used to assess mutagenic effects. Mortality was high for males in all laser radiation groups and increased with time of exposure. Except for the group treated for 0.25 s, significant reductions in total F1 progeny also were demonstrated for all other experimentals when male parents were exposed to laser radiation. Females showed a high mortality when subjected to 0.4- and 0.5-s laser radiation. No F1 progeny were produced when parental females were exposed for 0.25, 0.4, and 0.5 s. Numbers of F1 progeny from females exposed to 0.04 s of laser radiation were significantly reduced. A comparison of weekly mean number of progeny showed that the important differences in productivity occurred during the first and second week, respectively, when either male or female adult parents were subjected to laser radiation.

  19. Diagnostic methodology is critical for accurately determining the prevalence of ichthyophonus infections in wild fish populations

    USGS Publications Warehouse

    Kocan, R.; Dolan, H.; Hershberger, P.

    2011-01-01

    Several different techniques have been employed to detect and identify Ichthyophonus spp. in infected fish hosts; these include macroscopic observation, microscopic examination of tissue squashes, histological evaluation, in vitro culture, and molecular techniques. Examination of the peer-reviewed literature revealed that when more than 1 diagnostic method is used, they often result in significantly different results; for example, when in vitro culture was used to identify infected trout in an experimentally exposed population, 98.7% of infected trout were detected, but when standard histology was used to confirm known infected tissues from wild salmon, it detected ~50% of low-intensity infections and ~85% of high-intensity infections. Other studies on different species reported similar differences. When we examined a possible mechanism to explain the disparity between different diagnostic techniques, we observed non-random distribution of the parasite in 3-dimensionally visualized tissue sections from infected hosts, thus providing a possible explanation for the different sensitivities of commonly used diagnostic techniques. Based on experimental evidence and a review of the peer-reviewed literature, we have concluded that in vitro culture is currently the most accurate diagnostic technique for determining infection prevalence of Ichthyophonus, particularly when the exposure history of the population is not known.

  20. Population genomics reveals a possible history of backcrossing and recombination in the gynogenetic fish Poecilia formosa.

    PubMed

    Alberici da Barbiano, Laura; Gompert, Zachariah; Aspbury, Andrea S; Gabor, Caitlin R; Nice, Chris C

    2013-08-20

    Unisexual sperm-dependent vertebrates are of hybrid origins, rare, and predicted to be short-lived as a result of several challenges arising from their mode of reproduction. In particular, because of a lack of recombination, clonal species are predicted to have a low potential to respond to natural selection. However, many unisexual sperm-dependent species persist, and assessing the genetic diversity present in these species is fundamental to understanding how they avoid extinction. We used population genomic methods to assess genotypic variation within the unisexual fish Poecilia formosa. Measures of admixture and population differentiation, as well as clustering analyses, indicate that the genomes of individuals of P. formosa are admixed and intermediate between Poecilia latipinna and Poecilia mexicana, consistent with the hypothesis of their hybrid origins. Bayesian genomic cline analyses indicate that about 12% of sampled loci exhibit patterns consistent with inheritance from only one parent. The estimation of observed heterozygosity clearly suggests that P. formosa is not comprised of direct descendants of a single nonrecombining asexual F1 hybrid individual. Additionally, the estimation of observed heterozygosity provides support for the hypothesis that the history of this unisexual species has included backcrossing with the parent species before the onset of gynogenesis. We also document high levels of variation among asexual individuals, which is attributable to recombination (historical or ongoing) and the accumulation of mutations. The high genetic variation suggests that this unisexual vertebrate has more potential to respond to natural selection than if they were frozen F1 hybrids.

  1. Population genomics reveals a possible history of backcrossing and recombination in the gynogenetic fish Poecilia formosa

    PubMed Central

    Alberici da Barbiano, Laura; Gompert, Zachariah; Aspbury, Andrea S.; Gabor, Caitlin R.; Nice, Chris C.

    2013-01-01

    Unisexual sperm-dependent vertebrates are of hybrid origins, rare, and predicted to be short-lived as a result of several challenges arising from their mode of reproduction. In particular, because of a lack of recombination, clonal species are predicted to have a low potential to respond to natural selection. However, many unisexual sperm-dependent species persist, and assessing the genetic diversity present in these species is fundamental to understanding how they avoid extinction. We used population genomic methods to assess genotypic variation within the unisexual fish Poecilia formosa. Measures of admixture and population differentiation, as well as clustering analyses, indicate that the genomes of individuals of P. formosa are admixed and intermediate between Poecilia latipinna and Poecilia mexicana, consistent with the hypothesis of their hybrid origins. Bayesian genomic cline analyses indicate that about 12% of sampled loci exhibit patterns consistent with inheritance from only one parent. The estimation of observed heterozygosity clearly suggests that P. formosa is not comprised of direct descendants of a single nonrecombining asexual F1 hybrid individual. Additionally, the estimation of observed heterozygosity provides support for the hypothesis that the history of this unisexual species has included backcrossing with the parent species before the onset of gynogenesis. We also document high levels of variation among asexual individuals, which is attributable to recombination (historical or ongoing) and the accumulation of mutations. The high genetic variation suggests that this unisexual vertebrate has more potential to respond to natural selection than if they were frozen F1 hybrids. PMID:23918384

  2. Effects of crossovers between homeologs on inheritance and population genomics in polyploid-derived salmonid fishes.

    PubMed

    Allendorf, Fred W; Bassham, Susan; Cresko, William A; Limborg, Morten T; Seeb, Lisa W; Seeb, James E

    2015-01-01

    A whole genome duplication occurred in the ancestor of all salmonid fishes some 50-100 million years ago. Early inheritance studies with allozymes indicated that loci in the salmonid genome are inherited disomically in females. However, some pairs of duplicated loci showed patterns of inheritance in males indicating pairing and recombination between homeologous chromosomes. Nearly 20% of loci in the salmonid genome are duplicated and share the same alleles (isoloci), apparently due to homeologous recombination. Half-tetrad analysis revealed that isoloci tend to be telomeric. These results suggested that residual tetrasomic inheritance of isoloci results from homeologous recombination near chromosome ends and that continued disomic inheritance resulted from homologous pairing of centromeric regions. Many current genetic maps of salmonids are based on single nucleotide polymorphisms and microsatellites that are no longer duplicated. Therefore, long sections of chromosomes on these maps are poorly represented, especially telomeric regions. In addition, preferential multivalent pairing of homeologs from the same species in F1 hybrids results in an excess of nonparental gametes (so-called pseudolinkage). We consider how not including duplicated loci has affected our understanding of population and evolutionary genetics of salmonids, and we discuss how incorporating these loci will benefit our understanding of population genomics. PMID:25838153

  3. COLLAPSE OF A FISH POPULATION FOLLOWING EXPOSURE TO A SYNTHETIC ESTROGEN

    EPA Science Inventory

    Municipal wastewaters are a complex mixture containing estrogens and estrogen mimics that are known to affect the reproductive health of wild fishes. Male fishes downstream of some wastewater outfalls produce vitellogenin (VTG) (a protein normally synthesized by females during oo...

  4. Does cannibalism of larvae by adults affect settlement and connectivity of mussel populations?

    NASA Astrophysics Data System (ADS)

    Porri, Francesca; Jordaan, Tembisa; McQuaid, Christopher D.

    2008-09-01

    Intertidal population dynamics are driven by a complex series of processes, including larval supply and the possibility of larval predation by benthic animals such as filter-feeders. We hypothesised that cannibalism by adults could play a major role in the population connectivity of mussel populations by removing larvae as they attempt to settle in the adult habitat. Specifically, we tested hypotheses that consumption of mussel larvae by adults removes a significant proportion of potential settlers and is influenced by both settlement intensity and tidal state (flooding or ebbing). Predation of mussel larvae by adult mussels was investigated on incoming and ebbing tides during four spring tides by analysing the gut contents of adult Perna perna and Mytilus galloprovincialis collected from the low intertidal mussel zone between October 2005 and January 2006. Consumption rates were then compared with estimates of successful settler densities on natural beds. The results showed that mortality of competent mussel larvae through adult ingestion removes up to 77% a of potential settlers. Rates of larval consumption were highest during months of intense settlement, suggesting that mussels feed opportunistically, filtering a relatively fixed volume of water and removing particles, including larvae, in proportion to their densities in the water. Rates of larviphagy were also higher during receding than incoming tides. We suggest that this is due to changes in larval density or, more probably, in adult filtration efficiency that are related to the state of the tide. Despite significant effects of both tidal state and settlement intensity on rates of larval ingestion, neither had a significant effect on the proportion of potential settlers removed. During settlement more than half of all potential settlers are lost through cannibalism, with potentially serious consequences for population maintenance. The results highlight the paradoxical nature of the evolution of settlement

  5. Effects of a Low Dose of Fish Oil on Inflammatory Markers of Brazilian HIV-Infected Adults on Antiretroviral Therapy: A Randomized, Parallel, Placebo-Controlled Trial

    PubMed Central

    Oliveira, Julicristie M.; Rondó, Patrícia H. C.; Lima, Lourdes R. A. V.; Fortuna, Elizabeth S.; Yudkin, John S.

    2015-01-01

    Background: The benefits of antiretroviral therapy for HIV-infected subjects have been limited by an increased risk of metabolic and cardiovascular diseases. The objective of this study was to assess the effects of a low dose of marine omega-3 fatty acids on inflammatory marker concentrations in HIV-infected subjects under antiretroviral therapy (ART). Methods: This was a randomized, parallel, placebo-controlled trial that investigated the effects of 3 g fish oil/day (540 mg of eicosapentaenoic acid—EPA plus 360 mg of docosahexaenoic acid—DHA) or 3 g soy oil/day (placebo) for 24 weeks in 83 male and non-pregnant female HIV-infected adults on ART. Results: There were no differences between groups for the measures at baseline. Multilevel analyses revealed no statistically significant relationship between the longitudinal changes in high sensitivity-C reactive protein (hs-CRP) (Wald Chi2 = 0.17, p = 0.918), fibrinogen (Wald Chi2 = 3.82, p = 0.148), and factor VIII (Wald Chi2 = 5.25, p = 0.073) with fish oil. No significant changes in interleukin-6 (IL6), interleukin-1 beta (IL1-beta) and tumor necrosis factor-alpha (TNF-alpha) serum concentrations were observed with fish oil supplements for 12 weeks. Conclusions: Compared to placebo, a low dose of 900 mg omega-3 fatty acids (EPA plus DHA) in fish oil capsules did not change hs-CRP, fibrinogen, factor VIII, IL6, IL1-beta and TNF-alpha serum concentrations in HIV-infected subjects on ART. Further investigations should consider the assessment of more sensitive inflammatory markers or higher doses to evaluate the effects of marine omega-3 fatty acids in this population. Registered at the Nederlands Trial Register, Identifier no. NTR1798. PMID:26251920

  6. Population growth rates of reef sharks with and without fishing on the great barrier reef: robust estimation with multiple models.

    PubMed

    Hisano, Mizue; Connolly, Sean R; Robbins, William D

    2011-01-01

    Overfishing of sharks is a global concern, with increasing numbers of species threatened by overfishing. For many sharks, both catch rates and underwater visual surveys have been criticized as indices of abundance. In this context, estimation of population trends using individual demographic rates provides an important alternative means of assessing population status. However, such estimates involve uncertainties that must be appropriately characterized to credibly and effectively inform conservation efforts and management. Incorporating uncertainties into population assessment is especially important when key demographic rates are obtained via indirect methods, as is often the case for mortality rates of marine organisms subject to fishing. Here, focusing on two reef shark species on the Great Barrier Reef, Australia, we estimated natural and total mortality rates using several indirect methods, and determined the population growth rates resulting from each. We used bootstrapping to quantify the uncertainty associated with each estimate, and to evaluate the extent of agreement between estimates. Multiple models produced highly concordant natural and total mortality rates, and associated population growth rates, once the uncertainties associated with the individual estimates were taken into account. Consensus estimates of natural and total population growth across multiple models support the hypothesis that these species are declining rapidly due to fishing, in contrast to conclusions previously drawn from catch rate trends. Moreover, quantitative projections of abundance differences on fished versus unfished reefs, based on the population growth rate estimates, are comparable to those found in previous studies using underwater visual surveys. These findings appear to justify management actions to substantially reduce the fishing mortality of reef sharks. They also highlight the potential utility of rigorously characterizing uncertainty, and applying multiple

  7. Population Growth Rates of Reef Sharks with and without Fishing on the Great Barrier Reef: Robust Estimation with Multiple Models

    PubMed Central

    Hisano, Mizue; Connolly, Sean R.; Robbins, William D.

    2011-01-01

    Overfishing of sharks is a global concern, with increasing numbers of species threatened by overfishing. For many sharks, both catch rates and underwater visual surveys have been criticized as indices of abundance. In this context, estimation of population trends using individual demographic rates provides an important alternative means of assessing population status. However, such estimates involve uncertainties that must be appropriately characterized to credibly and effectively inform conservation efforts and management. Incorporating uncertainties into population assessment is especially important when key demographic rates are obtained via indirect methods, as is often the case for mortality rates of marine organisms subject to fishing. Here, focusing on two reef shark species on the Great Barrier Reef, Australia, we estimated natural and total mortality rates using several indirect methods, and determined the population growth rates resulting from each. We used bootstrapping to quantify the uncertainty associated with each estimate, and to evaluate the extent of agreement between estimates. Multiple models produced highly concordant natural and total mortality rates, and associated population growth rates, once the uncertainties associated with the individual estimates were taken into account. Consensus estimates of natural and total population growth across multiple models support the hypothesis that these species are declining rapidly due to fishing, in contrast to conclusions previously drawn from catch rate trends. Moreover, quantitative projections of abundance differences on fished versus unfished reefs, based on the population growth rate estimates, are comparable to those found in previous studies using underwater visual surveys. These findings appear to justify management actions to substantially reduce the fishing mortality of reef sharks. They also highlight the potential utility of rigorously characterizing uncertainty, and applying multiple

  8. Population growth rates of reef sharks with and without fishing on the great barrier reef: robust estimation with multiple models.

    PubMed

    Hisano, Mizue; Connolly, Sean R; Robbins, William D

    2011-01-01

    Overfishing of sharks is a global concern, with increasing numbers of species threatened by overfishing. For many sharks, both catch rates and underwater visual surveys have been criticized as indices of abundance. In this context, estimation of population trends using individual demographic rates provides an important alternative means of assessing population status. However, such estimates involve uncertainties that must be appropriately characterized to credibly and effectively inform conservation efforts and management. Incorporating uncertainties into population assessment is especially important when key demographic rates are obtained via indirect methods, as is often the case for mortality rates of marine organisms subject to fishing. Here, focusing on two reef shark species on the Great Barrier Reef, Australia, we estimated natural and total mortality rates using several indirect methods, and determined the population growth rates resulting from each. We used bootstrapping to quantify the uncertainty associated with each estimate, and to evaluate the extent of agreement between estimates. Multiple models produced highly concordant natural and total mortality rates, and associated population growth rates, once the uncertainties associated with the individual estimates were taken into account. Consensus estimates of natural and total population growth across multiple models support the hypothesis that these species are declining rapidly due to fishing, in contrast to conclusions previously drawn from catch rate trends. Moreover, quantitative projections of abundance differences on fished versus unfished reefs, based on the population growth rate estimates, are comparable to those found in previous studies using underwater visual surveys. These findings appear to justify management actions to substantially reduce the fishing mortality of reef sharks. They also highlight the potential utility of rigorously characterizing uncertainty, and applying multiple

  9. Estimating fish consumption and targeting high risk consumer populations in NJ and NY

    EPA Science Inventory

    An estimated 16.4% of US females of reproductive age (15 to 45 years) eat fish at least once per day. While fish is a good source of protein, with some species high in the omega-3 fatty acids that are associated with cardiovascular health, studies also indicate some fish and she...

  10. Caregiver Abuse of Chicago Chinese Older Adults in a Community-Dwelling Population

    PubMed Central

    Dong, Xin Qi; Li, Ge

    2016-01-01

    Objectives This study aimed to examine the prevalence and correlates of elder abuse reported by adult children among U.S Chinese populations. Method A community-based participatory research approach was implemented. A total of 548 Chinese adult children aged 21 years and over participated in this study. Elder abuse reported by adult children was assessed using Caregiver Abuse Screen (CASE). Results This study found a prevalence of 59.8%for elder abuse among 548 adult children. Younger age (r = −0.10, p < .05), higher level of education (r = 0.20, p < .001), higher income (r = 0.14, p < .01), more years in the U.S. (r = 0.12, p < .05), not born in Mainland China (r = −0.13, p < .01), and English-speaking (r = 0.16, p < .001) were positively correlated with elder abuse reported by adult children. Discussion Elder abuse by adult children is prevalent among U.S. Chinese populations. It is necessary for researchers, health care providers and policy makers to put more attention on elder abuse by adult children. Longitudinal research is needed to explore the risk factors associated with elder abuse by adult children. Health care providers should improve detection of elder abuse and support at-risk caregivers. Policy makers may consider cultural sensitive approaches to address elder abuse. PMID:27606358

  11. Evaluation of Fluoride Retention Due to Most Commonly Consumed Estuarine Fishes Among Fish Consuming Population of Andhra Pradesh as a Contributing Factor to Dental Fluorosis: A Cross-Sectional Study

    PubMed Central

    Ganta, Shravani; Nagaraj, Anup; Pareek, Sonia; Sidiq, Mohsin; Singh, Kushpal; Vishnani, Preeti

    2015-01-01

    Background Fluoride in drinking water is known for both beneficial and detrimental effects on health. The principal sources of fluoride include water, some species of vegetation, certain edible marine animals, dust and industrial processes. The purpose of this study was to evaluate the fluoride retention of most commonly consumed estuarine fishes among fish consuming population of Andhra Pradesh. Materials and Methods A cross-sectional study was conducted to evaluate the amount of fluoride retention due to ten most commonly consumed estuarine fishes as a contributing factor to Fluorosis by SPADNS Spectrophotometric method. The presence and severity of dental fluorosis among fish consuming population was recorded using Community Fluorosis Index. Statistical analysis was done using MedCalc v12.2.1.0 software. Results For Sea water fishes, the fluoride levels in bone were maximum in Indian Sardine (4.22 ppm). Amongst the river water fishes, the fluoride levels in bone were maximum in Catla (1.51 ppm). Also, the mean total fluoride concentrations of all the river fishes in skin, muscle and bone were less (0.86 ppm) as compared to the sea water fishes (2.59 ppm). It was unveiled that sea fishes accumulate relatively large amounts of Fluoride as compared to the river water fishes. The mean Community Fluorosis Index was found to be 1.06 amongst a sampled fish consuming population. Evaluation by Community Index for Dental fluorosis (CFI) suggested that fluorosis is of medium public health importance. Conclusion It was analysed that bone tends to accumulate more amount of fluoride followed by muscle and skin which might be due to the increased permeability and chemical trapping of fluoride inside the tissues. The amount of fluoride present in the fishes is directly related to the severity of fluorosis amongst fish consuming population, suggesting fishes as a contributing factor to fluorosis depending upon the dietary consumption. PMID:26266208

  12. Estimating total population size for adult female sea turtles: Accounting for non-nesters

    USGS Publications Warehouse

    Kendall, W.L.; Richardson, J.I.; Rees, Alan F.

    2008-01-01

    Assessment of population size and changes therein is important to sea turtle management and population or life history research. Investigators might be interested in testing hypotheses about the effect of current population size or density (number of animals per unit resource) on future population processes. Decision makers might want to determine a level of allowable take of individual turtles of specified life stage. Nevertheless, monitoring most stages of sea turtle life histories is difficult, because obtaining access to individuals is difficult. Although in-water assessments are becoming more common, nesting females and their hatchlings remain the most accessible life stages. In some cases adult females of a given nesting population are sufficiently philopatric that the population itself can be well defined. If a well designed tagging study is conducted on this population, survival, breeding probability, and the size of the nesting population in a given year can be estimated. However, with published statistical methodology the size of the entire breeding population (including those females skipping nesting in that year) cannot be estimated without assuming that each adult female in this population has the same probability of nesting in a given year (even those that had just nested in the previous year). We present a method for estimating the total size of a breeding population (including nesters those skipping nesting) from a tagging study limited to the nesting population, allowing for the probability of nesting in a given year to depend on an individual's nesting status in the previous year (i.e., a Markov process). From this we further develop estimators for rate of growth from year to year in both nesting population and total breeding population, and the proportion of the breeding population that is breeding in a given year. We also discuss assumptions and apply these methods to a breeding population of hawksbill sea turtles (Eretmochelys imbricata) from

  13. Characterization of MHC class IIB for four endangered Australian freshwater fishes obtained from ecologically divergent populations.

    PubMed

    Bracamonte, Seraina E; Smith, Steve; Hammer, Michael; Pavey, Scott A; Sunnucks, Paul; Beheregaray, Luciano B

    2015-10-01

    Genetic diversity is an essential aspect of species viability, and assessments of neutral genetic diversity are regularly implemented in captive breeding and conservation programs. Despite their importance, information from adaptive markers is rarely included in such programs. A promising marker of significance in fitness and adaptive potential is the major histocompatibility complex (MHC), a key component of the adaptive immune system. Populations of Australian freshwater fishes are generally declining in numbers due to human impacts and the introduction of exotic species, a scenario of particular concern for members of the family Percichthyidae, several of which are listed as nationally vulnerable or endangered, and hence subject to management plans, captive breeding, and restoration plans. We used a next-generation sequencing approach to characterize the MHC IIB locus and provide a conservative description of its levels of diversity in four endangered percichthyids: Gadopsis marmoratus, Macquaria australasica, Nannoperca australis, and Nannoperca obscura. Evidence is presented for a duplicated MHC IIB locus, positively selected sites and recombination of MHC alleles. Relatively moderate levels of diversity were detected in the four species, as well as in different ecotypes within each species. Phylogenetic analyses revealed genus specific clustering of alleles and no allele sharing among species. There were also no shared alleles observed between two ecotypes within G. marmoratus and within M. australasica, which might be indicative of ecologically-driven divergence and/or long divergence times. This represents the first characterization and assessment of MHC diversity for Percichthyidae, and also for Australian freshwater fishes in general, providing key genetic resources for a vertebrate group of increasing conservation concern.

  14. The species flocks of East African cichlid fishes: recent advances in molecular phylogenetics and population genetics

    NASA Astrophysics Data System (ADS)

    Salzburger, Walter; Meyer, Axel

    With more than 3,000 species, the fish family Cichlidae is one of the most species-rich families of vertebrates. Cichlids occur in southern and central America, Africa, Madagascar, and India. The hotspot of their biodiversity is East Africa, where they form adaptive radiations composed of hundreds of endemic species in several lakes of various sizes and ages. The unparalleled species richness of East African cichlids has been something of a conundrum for evolutionary biologists and ecologists, since it has been in doubt whether these hundreds of species arose by allopatric speciation or whether it is necessary to invoke somewhat less traditional models of speciation, such as micro-allopatric, peripatric, or even sympatric speciation or evolution through sexual selection mediated by female choice. Ernst Mayr's analyses of these evolutionary uniquely diverse species assemblages have contributed to a more direct approach to this problem and have led to a deeper understanding of the patterns and processes that caused the formation of these huge groups of species. We review here recent molecular data on population differentiation and phylogenetics, which have helped to unravel, to some extent, the patterns and processes that led to the formation and ecological maintenance of cichlid species flocks. It is becoming apparent that sexually selected traits do play an important role in speciation in micro-allopatric or even sympatric settings. Species richness seems to be roughly correlated with the surface area, but not the age, of the lakes. We observe that the oldest lineages of a species flock of cichlids are often less species-rich and live in the open water or deepwater habitats. While the species flocks of the Lake Malawai and the Lake Victoria areas were shown to be monophyletic, the cichlid assemblage of Lake Tanganyika seems to consist of several independent species flocks. Cichlids emerge as an evolutionary model system in which many fundamental questions in

  15. Larval dispersal connects fish populations in a network of marine protected areas

    PubMed Central

    Planes, Serge; Jones, Geoffrey P.; Thorrold, Simon R.

    2009-01-01

    Networks of no-take marine protected areas (MPAs) have been widely advocated for the conservation of marine biodiversity. But for MPA networks to be successful in protecting marine populations, individual MPAs must be self-sustaining or adequately connected to other MPAs via dispersal. For marine species with a dispersive larval stage, populations within MPAs require either the return of settlement-stage larvae to their natal reserve or connectivity among reserves at the spatial scales at which MPA networks are implemented. To date, larvae have not been tracked when dispersing from one MPA to another, and the relative magnitude of local retention and connectivity among MPAs remains unknown. Here we use DNA parentage analysis to provide the first direct estimates of connectivity of a marine fish, the orange clownfish (Amphiprion percula), in a proposed network of marine reserves in Kimbe Bay, Papua New Guinea. Approximately 40% of A. percula larvae settling into anemones in an island MPA at 2 different times were derived from parents resident in the reserve. We also located juveniles spawned by Kimbe Island residents that had dispersed as far as 35 km to other proposed MPAs, the longest distance that marine larvae have been directly tracked. These dispersers accounted for up to 10% of the recruitment in the adjacent MPAs. Our findings suggest that MPA networks can function to sustain resident populations both by local replenishment and through larval dispersal from other reserves. More generally, DNA parentage analysis provides a direct method for measuring larval dispersal for other marine organisms. PMID:19307588

  16. Life-history diversity and its importance to population stability and persistence of a migratory fish: steelhead in two large North American watersheds.

    PubMed

    Moore, Jonathan W; Yeakel, Justin D; Peard, Dean; Lough, Jeff; Beere, Mark

    2014-09-01

    Life-history strategies can buffer individuals and populations from environmental variability. For instance, it is possible that asynchronous dynamics among different life histories can stabilize populations through portfolio effects. Here, we examine life-history diversity and its importance to stability for an iconic migratory fish species. In particular, we examined steelhead (Oncorhynchus mykiss), an anadromous and iteroparous salmonid, in two large, relatively pristine, watersheds, the Skeena and Nass, in north-western British Columbia, Canada. We synthesized life-history information derived from scales collected from adult steelhead (N = 7227) in these watersheds across a decade. These migratory fishes expressed 36 different manifestations of the anadromous life-history strategy, with 16 different combinations of freshwater and marine ages, 7·6% of fish performing multiple spawning migrations, and up to a maximum of four spawning migrations per lifetime. Furthermore, in the Nass watershed, various life histories were differently prevalent through time - three different life histories were the most prevalent in a given year, and no life history ever represented more than 45% of the population. These asynchronous dynamics among life histories decreased the variability of numerical abundance and biomass of the aggregated population so that it was > 20% more stable than the stability of the weighted average of specific life histories: evidence of a substantial portfolio effect. Year of ocean entry was a key driver of dynamics; the median correlation coefficient of abundance of life histories that entered the ocean the same year was 2·5 times higher than the median pairwise coefficient of life histories that entered the ocean at different times. Simulations illustrated how different elements of life-history diversity contribute to stability and persistence of populations. This study provides evidence that life-history diversity can dampen fluctuations in

  17. Effect of prehatching weightlessness on adult fish behavior in dynamic environments

    NASA Technical Reports Server (NTRS)

    Hoffman, R. B.; Salinas, G. A.; Boyd, J. F.; Baky, A. A.; Von Baumgarten, R. J.

    1978-01-01

    At 16-17 months of age, three groups of fish from the embryonated eggs in the ASTP killifish experiment were subjected to postflight tests consisting of rapidly changing environments. It was found that the group of fish with the least amount of development at orbital insertion (A-32) had a decreased rheotropism for both the moving background and the rotating water current tests when compared to ground control fish. Exposure to parabolic aircraft flight conditions revealed that the A-32 fish were less disoriented during zero gravity periods and were hypersensitive to high-gravity periods. These results suggested a modified vestibular competency due to a 9-d prehatching weightlessness exposure.

  18. Population-level assessments should be emphasized over community/ecosystem-level assessments. Environmental Sciences Division Publication No. 1535. [Concerning the impact of power plants on fish populations

    SciTech Connect

    Van Winkle, W

    1980-01-01

    Arguments are presented in favor of emphasizing population-level assessments over community/ecosystem-level assessments. The two approaches are compared on each of four issues: (1) the nature of entrainment/impingement impacts; (2) the ability to forecast reliably for a single fish population as contrasted to the ability to forecast for an aquatic community or ecosystem; (3) practical considerations involving money, manpower, time, and the need to make decisions; and (4) the nature of societal and economic concerns. The conclusion on each of these four issues is that population-level assessments provide the optimal approach for evaluating the effects of entrainment and impingement mortality.

  19. Habitat selection by breeding waterbirds at ponds with size-structured fish populations

    NASA Astrophysics Data System (ADS)

    Kloskowski, Janusz; Nieoczym, Marek; Polak, Marcin; Pitucha, Piotr

    2010-07-01

    Fish may significantly affect habitat use by birds, either as their prey or as competitors. Fish communities are often distinctly size-structured, but the consequences for waterbird assemblages remain poorly understood. We examined the effects of size structure of common carp ( Cyprinus carpio) cohorts together with other biotic and abiotic pond characteristics on the distribution of breeding waterbirds in a seminatural system of monocultured ponds, where three fish age classes were separately stocked. Fish age corresponded to a distinct fish size gradient. Fish age and total biomass, macroinvertebrate and amphibian abundance, and emergent vegetation best explained the differences in bird density between ponds. Abundance of animal prey other than fish (aquatic macroinvertebrates and larval amphibians) decreased with increasing carp age in the ponds. Densities of ducks and smaller grebes were strongly negatively associated with fish age/size gradient. The largest of the grebes, the piscivorous great crested grebe ( Podiceps cristatus), was the only species that preferred ponds with medium-sized fish and was positively associated with total fish biomass. Habitat selection by bitterns and most rallids was instead strongly influenced by the relative amount of emergent vegetation cover in the ponds. Our results show that fish size structure may be an important cue for breeding habitat choice and a factor affording an opportunity for niche diversification in avian communities.

  20. Habitat selection by breeding waterbirds at ponds with size-structured fish populations.

    PubMed

    Kloskowski, Janusz; Nieoczym, Marek; Polak, Marcin; Pitucha, Piotr

    2010-07-01

    Fish may significantly affect habitat use by birds, either as their prey or as competitors. Fish communities are often distinctly size-structured, but the consequences for waterbird assemblages remain poorly understood. We examined the effects of size structure of common carp (Cyprinus carpio) cohorts together with other biotic and abiotic pond characteristics on the distribution of breeding waterbirds in a seminatural system of monocultured ponds, where three fish age classes were separately stocked. Fish age corresponded to a distinct fish size gradient. Fish age and total biomass, macroinvertebrate and amphibian abundance, and emergent vegetation best explained the differences in bird density between ponds. Abundance of animal prey other than fish (aquatic macroinvertebrates and larval amphibians) decreased with increasing carp age in the ponds. Densities of ducks and smaller grebes were strongly negatively associated with fish age/size gradient. The largest of the grebes, the piscivorous great crested grebe (Podiceps cristatus), was the only species that preferred ponds with medium-sized fish and was positively associated with total fish biomass. Habitat selection by bitterns and most rallids was instead strongly influenced by the relative amount of emergent vegetation cover in the ponds. Our results show that fish size structure may be an important cue for breeding habitat choice and a factor affording an opportunity for niche diversification in avian communities.

  1. Experience in adult population in dengue outbreak in Delhi.

    PubMed

    Tripathi, B K; Gupta, B; Sinha, R S; Prasad, S; Sharma, D K

    1998-03-01

    A dengue outbreak has recently hit the Indian capital. We studied the clinical profile of adult patients. Five hundred and sixty patients of dengue infection were admitted in a specially created ward according to the criteria laid down by WHO. Haematemesis (28.28%), epistaxis (26.78%) and malena (14.28%) were some of the common presentations. Similarly lymphadenopathy, especially cervical (30.89%), palatal rashes (26.96%) and hepatomegaly (23.75%) were the most commonly encountered findings on physical examination. Most of the cases were of dengue fever with haemorrhage and only 2.5% cases were classified under dengue haemorrhagic fever or dengue shock syndrome. The average hospital stay was 3.4 days but only 9.8 hours in the eleven patients who died, suggesting their late arrival in preterminal situation giving little time for resuscitation. Thrombocytopenia was not a feature and only 12.85% patients had platelet count less than 70,000/cmm. Most of the patients who were admitted with thrombocytopenia, showed normalization in their platelet counts in next few days. Serological examination demonstrated evidence of recent dengue infection in 41.17% patients. Few patients required blood or platelet concentrate transfusion. Eleven patients died, three due to DIC, one of intracranial haemorrhage and seven due to massive gastric haemorrhage. Rest of the patients recovered completely. Thus we can conclude that recent outbreak in Delhi was of dengue fever with haemorrhage and mortality was very low in patients who came early to the hospital.

  2. What Is the Prevalence of Adult ADHD? Results of a Population Screen of 966 Adults

    ERIC Educational Resources Information Center

    Faraone, Stephen V.; Biederman, Joseph

    2005-01-01

    To provide a better estimate of the prevalence of ADHD in adulthood, the authors complete a telephone survey of 966 randomly selected adults. They compute two diagnoses from the survey data. Participants meeting "Diagnostic and Statistical Manual of Mental Disorders" (4th ed.) criteria for both childhood and adulthood are defined as narrow ADHD.…

  3. Mortality Among Adults With Intellectual Disability in England: Comparisons With the General Population

    PubMed Central

    Hosking, Fay J.; Shah, Sunil M.; Harris, Tess; DeWilde, Stephen; Beighton, Carole; Cook, Derek G.

    2016-01-01

    Objectives. To describe mortality among adults with intellectual disability in England in comparison with the general population. Methods. We conducted a cohort study from 2009 to 2013 using data from 343 general practices. Adults with intellectual disability (n = 16 666; 656 deaths) were compared with age-, gender-, and practice-matched controls (n = 113 562; 1358 deaths). Results. Adults with intellectual disability had higher mortality rates than controls (hazard ratio [HR] = 3.6; 95% confidence interval [CI] = 3.3, 3.9). This risk remained high after adjustment for comorbidity, smoking, and deprivation (HR = 3.1; 95% CI = 2.7, 3.4); it was even higher among adults with intellectual disability and Down syndrome or epilepsy. A total of 37.0% of all deaths among adults with intellectual disability were classified as being amenable to health care intervention, compared with 22.5% in the general population (HR = 5.9; 95% CI = 5.1, 6.8). Conclusions. Mortality among adults with intellectual disability is markedly elevated in comparison with the general population, with more than a third of deaths potentially amenable to health care interventions. This mortality disparity suggests the need to improve access to, and quality of, health care among people with intellectual disability. PMID:27310347

  4. Assessing the tolerance of fish and fish populations to environmental stress: The problems and methods of monitoring

    USGS Publications Warehouse

    Wedemeyer, G.A.; McLeay, D.; Goodyear, C.P.

    1984-01-01

    Environmental stress is an inescapable aspect of life in the aquatic environment. The chemical and physical demands of life underwater impose somewhat rigorous constraints on aquatic species (Smith, 1982a). Superimposed on such demands may be the additional. physiological constraints of particular ecological niches. It is true that aquatic species are adapted to these conditions, but this does not imply the absence of energy drains (Lugo, 1978). For example, thermophilic fishes must still cope physiologically with the demands of high temperatures even though they are adapted to high temperatures per se.

  5. Differences in the metabolic rates of exploited and unexploited fish populations: a signature of recreational fisheries induced evolution?

    PubMed

    Hessenauer, Jan-Michael; Vokoun, Jason C; Suski, Cory D; Davis, Justin; Jacobs, Robert; O'Donnell, Eileen

    2015-01-01

    Non-random mortality associated with commercial and recreational fisheries have the potential to cause evolutionary changes in fish populations. Inland recreational fisheries offer unique opportunities for the study of fisheries induced evolution due to the ability to replicate study systems, limited gene flow among populations, and the existence of unexploited reference populations. Experimental research has demonstrated that angling vulnerability is heritable in Largemouth Bass Micropterus salmoides, and is correlated with elevated resting metabolic rates (RMR) and higher fitness. However, whether such differences are present in wild populations is unclear. This study sought to quantify differences in RMR among replicated exploited and unexploited populations of Largemouth Bass. We collected age-0 Largemouth Bass from two Connecticut drinking water reservoirs unexploited by anglers for almost a century, and two exploited lakes, then transported and reared them in the same pond. Field RMR of individuals from each population was quantified using intermittent-flow respirometry. Individuals from unexploited reservoirs had a significantly higher mean RMR (6%) than individuals from exploited populations. These findings are consistent with expectations derived from artificial selection by angling on Largemouth Bass, suggesting that recreational angling may act as an evolutionary force influencing the metabolic rates of fishes in the wild. Reduced RMR as a result of fisheries induced evolution may have ecosystem level effects on energy demand, and be common in exploited recreational populations globally. PMID:26039091

  6. Differences in the Metabolic Rates of Exploited and Unexploited Fish Populations: A Signature of Recreational Fisheries Induced Evolution?

    PubMed Central

    Hessenauer, Jan-Michael; Vokoun, Jason C.; Suski, Cory D.; Davis, Justin; Jacobs, Robert; O’Donnell, Eileen

    2015-01-01

    Non-random mortality associated with commercial and recreational fisheries have the potential to cause evolutionary changes in fish populations. Inland recreational fisheries offer unique opportunities for the study of fisheries induced evolution due to the ability to replicate study systems, limited gene flow among populations, and the existence of unexploited reference populations. Experimental research has demonstrated that angling vulnerability is heritable in Largemouth Bass Micropterus salmoides, and is correlated with elevated resting metabolic rates (RMR) and higher fitness. However, whether such differences are present in wild populations is unclear. This study sought to quantify differences in RMR among replicated exploited and unexploited populations of Largemouth Bass. We collected age-0 Largemouth Bass from two Connecticut drinking water reservoirs unexploited by anglers for almost a century, and two exploited lakes, then transported and reared them in the same pond. Field RMR of individuals from each population was quantified using intermittent-flow respirometry. Individuals from unexploited reservoirs had a significantly higher mean RMR (6%) than individuals from exploited populations. These findings are consistent with expectations derived from artificial selection by angling on Largemouth Bass, suggesting that recreational angling may act as an evolutionary force influencing the metabolic rates of fishes in the wild. Reduced RMR as a result of fisheries induced evolution may have ecosystem level effects on energy demand, and be common in exploited recreational populations globally. PMID:26039091

  7. Differences in the metabolic rates of exploited and unexploited fish populations: a signature of recreational fisheries induced evolution?

    PubMed

    Hessenauer, Jan-Michael; Vokoun, Jason C; Suski, Cory D; Davis, Justin; Jacobs, Robert; O'Donnell, Eileen

    2015-01-01

    Non-random mortality associated with commercial and recreational fisheries have the potential to cause evolutionary changes in fish populations. Inland recreational fisheries offer unique opportunities for the study of fisheries induced evolution due to the ability to replicate study systems, limited gene flow among populations, and the existence of unexploited reference populations. Experimental research has demonstrated that angling vulnerability is heritable in Largemouth Bass Micropterus salmoides, and is correlated with elevated resting metabolic rates (RMR) and higher fitness. However, whether such differences are present in wild populations is unclear. This study sought to quantify differences in RMR among replicated exploited and unexploited populations of Largemouth Bass. We collected age-0 Largemouth Bass from two Connecticut drinking water reservoirs unexploited by anglers for almost a century, and two exploited lakes, then transported and reared them in the same pond. Field RMR of individuals from each population was quantified using intermittent-flow respirometry. Individuals from unexploited reservoirs had a significantly higher mean RMR (6%) than individuals from exploited populations. These findings are consistent with expectations derived from artificial selection by angling on Largemouth Bass, suggesting that recreational angling may act as an evolutionary force influencing the metabolic rates of fishes in the wild. Reduced RMR as a result of fisheries induced evolution may have ecosystem level effects on energy demand, and be common in exploited recreational populations globally.

  8. The prevalence of food hypersensitivity in an unselected population of children and adults.

    PubMed

    Osterballe, M; Hansen, T K; Mortz, C G; Høst, A; Bindslev-Jensen, C

    2005-11-01

    A rising prevalence of food hypersensitivity (FHS) and severe allergic reactions to food has been reported the last decade. To estimate the prevalence of FHS to the most common allergenic foods in an unselected population of children and adults. We investigated a cohort of 111 children <3 yr of age, 486 children 3 yr of age, 301 children older than 3 yr of age and 936 adults by questionnaire, skin prick test, histamine release test and specific immunoglobulin E followed by oral challenge to the most common allergenic foods. In total, 698 cases of possible FHS were recorded in 304 (16.6%) participants. The prevalence of FHS confirmed by oral challenge was 2.3% in the children 3 yr of age, 1% in children older than 3 yr of age and 3.2% in adults. The most common allergenic foods were hen's egg affecting 1.6% of the children 3 yr of age and peanut in 0.4% of the adults. Of the adults, 0.2% was allergic to codfish and 0.3% to shrimp, whereas no challenges with codfish and shrimp were positive in the children. The prevalence of clinical reactions to pollen-related foods in pollen-sensitized adults was estimated to 32%. This study demonstrates the prevalence of FHS confirmed by oral challenge to the most common allergenic foods in an unselected population of children and adults.

  9. Population Structure and Adaptive Divergence in a High Gene Flow Marine Fish: The Small Yellow Croaker (Larimichthys polyactis).

    PubMed

    Liu, Bing-Jian; Zhang, Bai-Dong; Xue, Dong-Xiu; Gao, Tian-Xiang; Liu, Jin-Xian

    2016-01-01

    The spatial distribution of genetic diversity has been long considered as a key component of policy development for management and conservation of marine fishes. However, unraveling the population genetic structure of migratory fish species is challenging due to high potential for gene flow. Despite the shallow population differentiation revealed by putatively neutral loci, the higher genetic differentiation with panels of putatively adaptive loci could provide greater resolution for stock identification. Here, patterns of population differentiation of small yellow croaker (Larimichthys polyactis) were investigated by genotyping 15 highly polymorphic microsatellites in 337 individuals of 15 geographic populations collected from both spawning and overwintering grounds. Outlier analyses indicated that the locus Lpol03 might be under directional selection, which showed a strong homology with Grid2 gene encoding the glutamate receptor δ2 protein (GluRδ2). Based on Lpol03, two distinct clusters were identified by both STRUCTURE and PCoA analyses, suggesting that there were two overwintering aggregations of L. polyactis. A novel migration pattern was suggested for L. polyactis, which was inconsistent with results of previous studies based on historical fishing yield statistics. These results provided new perspectives on the population genetic structure and migratory routes of L. polyactis, which could have significant implications for sustainable management and utilization of this important fishery resource. PMID:27100462

  10. Population Structure and Adaptive Divergence in a High Gene Flow Marine Fish: The Small Yellow Croaker (Larimichthys polyactis)

    PubMed Central

    Xue, Dong-Xiu; Gao, Tian-Xiang; Liu, Jin-Xian

    2016-01-01

    The spatial distribution of genetic diversity has been long considered as a key component of policy development for management and conservation of marine fishes. However, unraveling the population genetic structure of migratory fish species is challenging due to high potential for gene flow. Despite the shallow population differentiation revealed by putatively neutral loci, the higher genetic differentiation with panels of putatively adaptive loci could provide greater resolution for stock identification. Here, patterns of population differentiation of small yellow croaker (Larimichthys polyactis) were investigated by genotyping 15 highly polymorphic microsatellites in 337 individuals of 15 geographic populations collected from both spawning and overwintering grounds. Outlier analyses indicated that the locus Lpol03 might be under directional selection, which showed a strong homology with Grid2 gene encoding the glutamate receptor δ2 protein (GluRδ2). Based on Lpol03, two distinct clusters were identified by both STRUCTURE and PCoA analyses, suggesting that there were two overwintering aggregations of L. polyactis. A novel migration pattern was suggested for L. polyactis, which was inconsistent with results of previous studies based on historical fishing yield statistics. These results provided new perspectives on the population genetic structure and migratory routes of L. polyactis, which could have significant implications for sustainable management and utilization of this important fishery resource. PMID:27100462

  11. Population Structure and Adaptive Divergence in a High Gene Flow Marine Fish: The Small Yellow Croaker (Larimichthys polyactis).

    PubMed

    Liu, Bing-Jian; Zhang, Bai-Dong; Xue, Dong-Xiu; Gao, Tian-Xiang; Liu, Jin-Xian

    2016-01-01

    The spatial distribution of genetic diversity has been long considered as a key component of policy development for management and conservation of marine fishes. However, unraveling the population genetic structure of migratory fish species is challenging due to high potential for gene flow. Despite the shallow population differentiation revealed by putatively neutral loci, the higher genetic differentiation with panels of putatively adaptive loci could provide greater resolution for stock identification. Here, patterns of population differentiation of small yellow croaker (Larimichthys polyactis) were investigated by genotyping 15 highly polymorphic microsatellites in 337 individuals of 15 geographic populations collected from both spawning and overwintering grounds. Outlier analyses indicated that the locus Lpol03 might be under directional selection, which showed a strong homology with Grid2 gene encoding the glutamate receptor δ2 protein (GluRδ2). Based on Lpol03, two distinct clusters were identified by both STRUCTURE and PCoA analyses, suggesting that there were two overwintering aggregations of L. polyactis. A novel migration pattern was suggested for L. polyactis, which was inconsistent with results of previous studies based on historical fishing yield statistics. These results provided new perspectives on the population genetic structure and migratory routes of L. polyactis, which could have significant implications for sustainable management and utilization of this important fishery resource.

  12. Laboratory mating trials indicate incipient speciation by sexual selection among populations of the cichlid fish Pseudotropheus zebra from Lake Malawi.

    PubMed Central

    Knight, Mairi E.; Turner, George F.

    2004-01-01

    It has been suggested that sexual selection may have played a major role in the rapid evolution of hundreds of species of cichlid fishes in Lake Malawi. We report the results of a laboratory test of assortative mating among Lake Malawi cichlid fishes from five closely related geographical populations differing in male courtship colour. Paternity of clutches was tested using microsatellite DNA typing of offspring. Out of 1955 offspring typed, 1296 (66.3%) were sired by the male from the same population as the female, which is more than three times the rate expected if females do not differentiate among males of the different populations (20%). This result indicates that mate preferences of geographical races are strongly differentiated, consistent with the races representing incipient geographical species diverging under sexual selection exerted by female preferences for different male courtship colours. PMID:15209099

  13. Raw Fish Consuming Behavior Related to Liver Fluke Infection among Populations at Risk of Cholangiocarcinoma in Nakhon Ratchasima Province, Thailand.

    PubMed

    Chavengkun, Wasugree; Kompor, Pontip; Norkaew, Jun; Kujapun, Jirawoot; Pothipim, Mali; Ponphimai, Sukanya; Kaewpitoon, Soraya J; Padchasuwan, Natnapa; Kaewpitoon, Natthawut

    2016-01-01

    Opisthorchiasis is a health problem in rural communities of Thailand, particularly in the northeast and north regions. Therefore, this study aimed to investigate raw fish consuming behavior related to liver fluke infection among the population at risk for opisthorchiasis and cholangiocarcinoma (CCA). A cross-sectional descriptive study was conducted in Meuang Yang district, Nakhon Ratchasima province, northeast Thailand, between June and October 2015. Participants were screened for CCA, and samples who had a high score of CCA risk were purposively selected. A predesigned questionnaire was utilized to collect the data from all participants. X2-test was used for analysis of associations between demographic data and raw fish consumption. The results revealed that participants had past histories of stool examination (33.0%), liver fluke infection (21.0%), praziquantel use (24.0%), raw fish consumption (78.0%), relatives family consuming raw fish (73.0%), and relatives family with CCA (3.0%). Participants consumed several dished related to liver fluke infection, mainly raw fermented fish (13.0%), under smoked catfish (5.00%), raw pickled fish (4.00%), and raw spicy minced fish salad (3.00%). The most common types of cyprinoid fish were Barbodes gonionotus (39%), Hampala dispar (38%), Puntius brevis (37%), Cyclocheilichthys armatus (33%), Puntioplites proctozysron (32%), and Luciosoma bleekeri (30%), respectively. Participants had a low level of knowledge (mean=3.79, SD=0.74), moderate attitude (mean=7.31, SD=7.31) and practice (mean=38.64, SD=6.95) regarding liver fluke prevention and control. Demographic variables like age (>36 years old; X2-test=17.794, p-value=0.001), education (primary school; X2-test=18.952, p-value=0.001), marital status (married; X2-test=12.399, p-value=0.002), and income (<5,000 baht; X2-test=27.757, p-value=0.015) were significantly associated with raw fish consumption. This result indicates that the population had risk consumption for liver

  14. Population genetic structure of the acanthocephalan Acanthosentis cheni in anadromous, freshwater, and landlocked stocks of its fish host, Coilia nasus.

    PubMed

    Song, Rui; Li, Wen X; Wu, Shan G; Zou, Hong; Wang, Gui T

    2014-04-01

    The acanthocephalan Acanthosentis cheni was found in anadromous, freshwater, and landlocked stocks of its fish host, Coilia nasus. To examine the genetic variations of the acanthocephalan among the 3 populations with the adaptation of the host to the freshwater, the genetic structure of the helminth was investigated in anadromous (Zhoushan and Chongming islands, and Anqing), freshwater (Anqing, Ezhou, and Poyang Lake), and landlocked (Tian'ezhou Reserve) populations by sequencing intergenic transcribed spacers (ITS) of the ribosomal RNA coding genes. Low Fst values and high gene flow were found among the 7 populations (Fst = 0.0135, P = 0.2723; Nm = 36.48) and the 3 ecotypes of Acanthosentis cheni (Fst = 0.0178, P = 0.1044; Nm = 27.67). On the other hand, significant genetic differentiation of the C. nasus host populations was detected between the upstream and downstream areas of Xiaogu Mountain (Fst = 0.1961, P = 0.0030; Nm = 2.05), which is the farthest location of spawning migration for C. nasus . However, the migration break of the fish host appeared not to cause significant genetic differentiation of A. cheni populations between the upper and lower reaches of Xiaogu Mountain. Other factors might promote genetic exchange of A. cheni populations such as dispersal of the intermediate host by flooding or other fish species serving as the definitive or paratenic hosts. In Anqing, nucleotide diversity of the acanthocephalan was highest in the freshwater population (0.0038) and lower in the anadromous population (0.0026). This suggested that new mutations may have occurred in the freshwater A. cheni population in Anqing when adapting to a freshwater environment.

  15. Multidimensional Clinical Phenotyping of an Adult Cystic Fibrosis Patient Population

    PubMed Central

    Conrad, Douglas J.; Bailey, Barbara A.

    2015-01-01

    Background Cystic Fibrosis (CF) is a multi-systemic disease resulting from mutations in the Cystic Fibrosis Transmembrane Regulator (CFTR) gene and has major manifestations in the sino-pulmonary, and gastro-intestinal tracts. Clinical phenotypes were generated using 26 common clinical variables to generate classes that overlapped quantiles of lung function and were based on multiple aspects of CF systemic disease. Methods The variables included age, gender, CFTR mutations, FEV1% predicted, FVC% predicted, height, weight, Brasfield chest xray score, pancreatic sufficiency status and clinical microbiology results. Complete datasets were compiled on 211 subjects. Phenotypes were identified using a proximity matrix generated by the unsupervised Random Forests algorithm and subsequent clustering by the Partitioning around Medoids (PAM) algorithm. The final phenotypic classes were then characterized and compared to a similar dataset obtained three years earlier. Findings Clinical phenotypes were identified using a clustering strategy that generated four and five phenotypes. Each strategy identified 1) a low lung health scores phenotype, 2) a younger, well-nourished, male-dominated class, 3) various high lung health score phenotypes that varied in terms of age, gender and nutritional status. This multidimensional clinical phenotyping strategy identified classes with expected microbiology results and low risk clinical phenotypes with pancreatic sufficiency. Interpretation This study demonstrated regional adult CF clinical phenotypes using non-parametric, continuous, ordinal and categorical data with a minimal amount of subjective data to identify clinically relevant phenotypes. These studies identified the relative stability of the phenotypes, demonstrated specific phenotypes consistent with published findings and identified others needing further study. PMID:25822311

  16. Contrasting Population and Diet Influences on Gut Length of an Omnivorous Tropical Fish, the Trinidadian Guppy (Poecilia reticulata)

    PubMed Central

    Zandonà, Eugenia; Auer, Sonya K.; Kilham, Susan S.; Reznick, David N.

    2015-01-01

    Phenotypic plasticity is advantageous for organisms that live in variable environments. The digestive system is particularly plastic, responding to changes in diet. Gut length is the result of a trade-off between maximum nutrient absorption and minimum cost for its maintenance and it can be influenced by diet and by evolutionary history. We assessed variation in gut length of Trinidadian guppies (Poecilia reticulata) as a function of diet, season, ontogeny, and local adaptation. Populations of guppies adapted to different predation levels have evolved different life history traits and have different diets. We sampled guppies from sites with low (LP) and high predation (HP) pressure in the Aripo and Guanapo Rivers in Trinidad. We collected fish during both the dry and wet season and assessed their diet and gut length. During the dry season, guppies from HP sites fed mostly on invertebrates, while guppies in the LP sites fed mainly on detritus. During the wet season, the diet of LP and HP populations became very similar. We did not find strong evidence of an ontogenetic diet shift. Gut length was negatively correlated with the proportion of invertebrates in diet across fish from all sites, supporting the hypothesis that guppy digestive systems adapt in length to changes in diet. Population of origin also had an effect on gut length, as HP and LP fish maintained different gut lengths even in the wet season, when their diets were very similar and individuals in both types of populations fed mostly on detritus. Thus, both environment and population of origin influenced guppies gut length, but population of origin seemed to have a stronger effect. Our study also showed that, even in omnivorous fish, gut length adapted to different diets, being more evident when the magnitude of difference between animal and plant material in the diet was very large. PMID:26360601

  17. Contrasting Population and Diet Influences on Gut Length of an Omnivorous Tropical Fish, the Trinidadian Guppy (Poecilia reticulata).

    PubMed

    Zandonà, Eugenia; Auer, Sonya K; Kilham, Susan S; Reznick, David N

    2015-01-01

    Phenotypic plasticity is advantageous for organisms that live in variable environments. The digestive system is particularly plastic, responding to changes in diet. Gut length is the result of a trade-off between maximum nutrient absorption and minimum cost for its maintenance and it can be influenced by diet and by evolutionary history. We assessed variation in gut length of Trinidadian guppies (Poecilia reticulata) as a function of diet, season, ontogeny, and local adaptation. Populations of guppies adapted to different predation levels have evolved different life history traits and have different diets. We sampled guppies from sites with low (LP) and high predation (HP) pressure in the Aripo and Guanapo Rivers in Trinidad. We collected fish during both the dry and wet season and assessed their diet and gut length. During the dry season, guppies from HP sites fed mostly on invertebrates, while guppies in the LP sites fed mainly on detritus. During the wet season, the diet of LP and HP populations became very similar. We did not find strong evidence of an ontogenetic diet shift. Gut length was negatively correlated with the proportion of invertebrates in diet across fish from all sites, supporting the hypothesis that guppy digestive systems adapt in length to changes in diet. Population of origin also had an effect on gut length, as HP and LP fish maintained different gut lengths even in the wet season, when their diets were very similar and individuals in both types of populations fed mostly on detritus. Thus, both environment and population of origin influenced guppies gut length, but population of origin seemed to have a stronger effect. Our study also showed that, even in omnivorous fish, gut length adapted to different diets, being more evident when the magnitude of difference between animal and plant material in the diet was very large.

  18. Contrasting Population and Diet Influences on Gut Length of an Omnivorous Tropical Fish, the Trinidadian Guppy (Poecilia reticulata).

    PubMed

    Zandonà, Eugenia; Auer, Sonya K; Kilham, Susan S; Reznick, David N

    2015-01-01

    Phenotypic plasticity is advantageous for organisms that live in variable environments. The digestive system is particularly plastic, responding to changes in diet. Gut length is the result of a trade-off between maximum nutrient absorption and minimum cost for its maintenance and it can be influenced by diet and by evolutionary history. We assessed variation in gut length of Trinidadian guppies (Poecilia reticulata) as a function of diet, season, ontogeny, and local adaptation. Populations of guppies adapted to different predation levels have evolved different life history traits and have different diets. We sampled guppies from sites with low (LP) and high predation (HP) pressure in the Aripo and Guanapo Rivers in Trinidad. We collected fish during both the dry and wet season and assessed their diet and gut length. During the dry season, guppies from HP sites fed mostly on invertebrates, while guppies in the LP sites fed mainly on detritus. During the wet season, the diet of LP and HP populations became very similar. We did not find strong evidence of an ontogenetic diet shift. Gut length was negatively correlated with the proportion of invertebrates in diet across fish from all sites, supporting the hypothesis that guppy digestive systems adapt in length to changes in diet. Population of origin also had an effect on gut length, as HP and LP fish maintained different gut lengths even in the wet season, when their diets were very similar and individuals in both types of populations fed mostly on detritus. Thus, both environment and population of origin influenced guppies gut length, but population of origin seemed to have a stronger effect. Our study also showed that, even in omnivorous fish, gut length adapted to different diets, being more evident when the magnitude of difference between animal and plant material in the diet was very large. PMID:26360601

  19. Maintaining population persistence in the face of an extremely altered hydrograph: implications for three sensitive fishes in a tributary of the Green River, Utah

    USGS Publications Warehouse

    Bottcher, Jared L.

    2009-01-01

    The ability of an organism to disperse to suitable habitats, especially in modified and fragmented systems, determines individual fitness and overall population viability. The bluehead sucker (Catostomus discobolus), flannelmouth sucker (Catostomus latipinnis), and roundtail chub (Gila robusta) are three species native to the upper Colorado River Basin that now occupy only 50% of their historic range. Despite these distributional declines, populations of all three species are present in the San Rafael River, a highly regulated tributary of the Green River, Utah, providing an opportunity for research. Our goal was to determine the timing and extent of movement, habitat preferences, and limiting factors, ultimately to guide effective management and recovery of these three species. In 2007-2008, we sampled fish from 25 systematically selected, 300-m reaches in the lower 64 km of the San Rafael River, spaced to capture the range of species, life-stages, and habitat conditions present. We implanted all target species with a passive integrated transponder (PIT) tag, installed a passive PIT tag antennae, and measured key habitat parameters throughout each reach and at the site of native fish capture. We used random forest modeling to identify and rank the most important abiotic and biotic predictor variables, and reveal potential limiting factors in the San Rafael River. While flannelmouth sucker were relatively evenly distributed within our study area, highest densities of roundtail chub and bluehead sucker occurred in isolated, upstream reaches characterized by complex habitat. In addition, our movement and length-frequency data indicate downstream drift of age-0 roundtail chub, and active upstream movement of adult flannelmouth sucker, both from source populations, providing the lower San Rafael River with colonists. Our random forest analysis highlights the importance of pools, riffles, and distance-to-source populations, suggesting that bluehead sucker and roundtail

  20. Response of fish populations to natural channel design restoration in streams of the Catskill Mountains, New York

    USGS Publications Warehouse

    Baldigo, Barry P.; Warren, D.R.; Ernst, A.G.; Mulvihill, C.I.

    2008-01-01

    Many streams and rivers throughout North America have been extensively straightened, widened, and hardened since the middle 1800s, but related effects on aquatic ecosystems have seldom been monitored, described, or published. Beginning in the early 1990s, reach-level restoration efforts began to base projects on natural channel design (NCD) techniques and Rosgen's (1994b, 1996) river classification system in an effort to duplicate or mimic stable reference reach geomorphology. Four reaches in three streams of the Catskill Mountains, New York, were restored from 2000 to 2002 using NCD techniques to decrease bed and bank erosion rates, decrease sediment loads, and improve water quality. The effects of restoration on the health of fish assemblages were assessed through a before-after, control-impact (BACI) study design to quantify the net changes in population and community indices at treatment reaches relative to index changes at unaltered reference reaches from 1999 to 2004. After restoration, community richness and biomass at treatment reaches increased by more than one-third. Changes in fish communities were caused mainly by shifts in dominant species populations; fish community biomass and total fish abundance were generally dominated by daces or daces and sculpins before restoration and by one or more salmonid species after restoration. Density and biomass of eastern blacknose dace Rhinichthys atratulus, longnose dace R. cataractae, and slimy sculpin Cottus cognatus did not change appreciably, whereas net salmonid density and biomass increased substantially after restoration. These changes were driven primarily by large increases in populations of brown trout Salmo trutta. The findings demonstrate that the structure, function, and ultimately the health of resident fish populations and communities can be improved, at least over the short term, through NCD restoration in perturbed streams of the Catskill Mountains. ?? Copyright by the American Fisheries Society

  1. Comparison of Statistical Population Reconstruction Using Full and Pooled Adult Age-Class Data

    PubMed Central

    Skalski, John R.; Millspaugh, Joshua J.; Clawson, Michael V.

    2012-01-01

    Background Age-at-harvest data are among the most commonly collected, yet neglected, demographic data gathered by wildlife agencies. Statistical population construction techniques can use this information to estimate the abundance of wild populations over wide geographic areas and concurrently estimate recruitment, harvest, and natural survival rates. Although current reconstruction techniques use full age-class data (0.5, 1.5, 2.5, 3.5, … years), it is not always possible to determine an animal's age due to inaccuracy of the methods, expense, and logistics of sample collection. The ability to inventory wild populations would be greatly expanded if pooled adult age-class data (e.g., 0.5, 1.5, 2.5+ years) could be successfully used in statistical population reconstruction. Methodology/Principal Findings We investigated the performance of statistical population reconstruction models developed to analyze full age-class and pooled adult age-class data. We performed Monte Carlo simulations using a stochastic version of a Leslie matrix model, which generated data over a wide range of abundance levels, harvest rates, and natural survival probabilities, representing medium-to-big game species. Results of full age-class and pooled adult age-class population reconstructions were compared for accuracy and precision. No discernible difference in accuracy was detected, but precision was slightly reduced when using the pooled adult age-class reconstruction. On average, the coefficient of variation increased by 0.059 when the adult age-class data were pooled prior to analyses. The analyses and maximum likelihood model for pooled adult age-class reconstruction are illustrated for a black-tailed deer (Odocoileus hemionus) population in Washington State. Conclusions/Significance Inventorying wild populations is one of the greatest challenges of wildlife agencies. These new statistical population reconstruction models should expand the demographic capabilities of wildlife agencies

  2. Studies of the limnology, fish populations, and fishery of Turquoise Lake, Colorado - 1979-80

    SciTech Connect

    Nesler, T.P.

    1981-07-01

    Turquoise Lake is one of the primary storage reservoirs in the Fryingpan-Arkansas Water Project and provides supplementary water by conduit to the MT. Elbert Forebay-Twin Lakes system for pump-back storage power generation. The reservoir may be characterized as a dimictic, cold-water lake that is well oxygenated, relatively unbuffed, and slightly acidic. The lake may be classified as oligotrophic on the basis of total dissolved solids, algal nutrients (N-P), and chlorophyll concentrations. Depletion of dissolved oxygen occurs regularly in the hypolimnion during late summer and late winter. Turquoise Lake is limnologically similar to Twin Lakes (Colo.) in most respects. Data contained in this report are useful to those interested in the limnology of high mountain lakes, including physical-chemical parameters, chlorophyll, plankton, and fish populations. Turquoise Lake provides source water to the Mt. Elbert forebay. Thus the baseline data provided here will be helpful in assessing the effects of pumped-storage powerplant operation on the limnology of Twin Lakes, Colo.

  3. [Regional characteristics of arterial hypertension in adult population of Croatia].

    PubMed

    Erceg, Marijan; Hrabak-Zerjavić, Vlasta; Ivicević Uhernik, Ana

    2007-06-01

    Data collected in the Croatian Health Survey launched in 2003 by the Ministry of Health and Social Welfare were analyzed. The survey included a regionally stratified random sample. Using the method of structured questionnaire and anthropometric measurements (blood pressure, height and weight), data were collected on 9,070 subjects aged >18. The mean systolic and diastolic blood pressure was calculated from two measurements. Inclusion criteria in the group of subjects with elevated blood pressure were the subject's reporting taking antihypertensive medication and/or mean systolic blood pressure > or =140 mm Hg, and/or mean diastolic blood pressure > or =90 mm Hg. Descriptive analysis was done on figures yielded by use of the SPSS software. Subjects with elevated blood pressure accounted for 44.2% (95%CI=42.61-45.85) of study population, with a h gher rate in male (45.6%; 95%= 43.14-48.06) and lower in female subjects (43.0%; 95%CI=41.46-44.55). Croatia was estimated to have 1,538,982 inhabitants with high blood pressure (748,072 males and 790,910 females). The proportion of individuals with elevated blood pressure was highest (78.9%; 95%CI=76.9-81.0; CV=1.32) in the 65 age group, followed by 35-64 age group 46.9% (95% CI=44.8-41.0; CV=2.3), and lowest rate (13.8%; 95%CI=11.1-16.6; CV=10.2) in the 18-34 age group. Regional distribution of high blood pressure was as follows: central Croatia 46.4% (95%CI=42.9-49.9; CV= 3.8), south 45.3% (95%CI= 40.9-49.7; CV=. 5.0), City of Zagreb 44.7% (95%CI= 40.9-48.5; CV= 4.3), east 44.2% (95%CI=40.5-47.8; CV=4.2), north 43.0% (95%CI=40.9-49.7; CV= 5.0), and west 40.5% (95%CI= 36.0-45.0; CV= 5.7). In the female group aged 35-64, regional distribution was as follows: east 52.3% (95%CI=46.0-58.7; CV=6.2), central Croatia 45.4% (95%CI=40.3-50.5; CV=5.7), City of Zagreb 43.5 (95%CI=38.1-48.9; CV=6.4), south 40.7% (95%CI=37.4-44, 0; CV=4.1), north 39.3% (95% CI=33.7-44.8; CV=7.2), and west 35.1% (95%CI=26.1-44.2; CV= 13.1). Differences

  4. Effects on life history variables and population dynamics following maternal metal exposure in the live-bearing fish Gambusia affinis.

    PubMed

    Cazan, Alfy Morales; Klerks, Paul L

    2015-04-01

    This study investigated the effect of maternal copper and maternal cadmium exposure on life history variables and population dynamics in a live-bearing fish species. Gravid females were exposed to copper, cadmium, or background metal levels (control); maternal transfer of the metals was previously demonstrated using the exact same design. Each female's first brood, born after the exposure, was subdivided into two groups. One group was raised in the laboratory, to assess time-to and size-at sexual maturity, reproductive output and other life history variables. Offspring from the other group were used to start four mesocosm populations for each treatment. These populations were sampled monthly, for about 18 months, to assess population dynamics. For the laboratory-reared fish, offspring of copper-exposed females reached sexual maturity at a smaller size than did offspring from the other treatments. Maternal copper exposure and maternal cadmium exposure both resulted in fewer broods and an increase in gestation time. No impacts were detected for brood size, inter-brood interval, time-to-sexual-maturity, or life span. In the greenhouse population study, no effect of maternal copper or cadmium exposure was evident for population parameters, other than that the relative abundance of juveniles and/or newborns was reduced in populations established with offspring of the exposed females. This study provided evidence that a short-term metal exposure of gravid females can negatively affect their offspring's life history variables and potentially influence population dynamics in a life-bearing fish species.

  5. Conduct disorder and adult psychiatric diagnoses: associations and gender differences in the U.S. adult population.

    PubMed

    Morcillo, Carmen; Duarte, Cristiane S; Sala, Regina; Wang, Shuai; Lejuez, Carl W; Kerridge, Bradley T; Blanco, Carlos

    2012-03-01

    The authors' objective was to examine the presence of Axis I and II psychiatric disorders among adult males and females with a history in childhood and/or adolescence of conduct disorder (CD). Data were derived from a large national sample of the U.S. population. Face-to-face interviews of more than 34,000 adults ages 18 years and older were conducted during 2004-2005 using the Alcohol Use Disorder and Associated Disabilities Interview Schedule-DSM-IV Version. After adjusting for sociodemographic characteristics and psychiatric comorbidity, CD was associated with all Axis I and II disorders, particularly substance use disorders (SUD), bipolar disorder, and histrionic personality disorders. After adjusting for gender differences in the general population, men had significantly greater odds of social anxiety disorder and paranoid personality disorder, whereas women were more likely to have SUD. Furthermore, there was dose-response relationship between number of CD symptoms and risk for most psychiatric disorders. From a clinical standpoint, knowledge of the gender differences in associations of CD with other psychiatric disorders in adulthood may be informative of developmental pathways of the disorder, and of possible gender-specific risk factors. Early recognition and treatment of CD may help prevent the development of adult-onset disorders.

  6. Population structure and reproductive period of two introduced fish species in a Brazilian semiarid region reservoir.

    PubMed

    Sousa, Marla Melise de Oliveira; Lopes, Suzany Iasnaya Moreira; da Costa, Rodrigo Silva; Novaes, José Luís Costa

    2015-09-01

    The Amazonian fish species Plagioscion squamosissimus (Sciaenidae) and Cichla monoculus Cichlidae), have been widely introduced into different reservoirs in Brazil, and have caused many negative mpacts on local fish fauna. The aim of this study was to evaluate the population structure (abundance, length structure, length-weight relationship, sex ratio, and length at first maturity) and the reprodutive period of these wo species in the Santa Cruz Reservoir (built in 2002), located in the Brazilian semiarid region, for their adequate management and local species conservation policies. Specimens were collected quarterly in eight sites from February 2010 to November 2013 using gillnets (12 to 70 mm mesh between adjacent knots). The specimens captured were counted and the following biometric and biological data were analysed: standard length, total weight, and reproductive data, such as, sex, weight and gonadal maturity stage. The species abundances were estimated by CPUE and expressed as the number of individuals per gill net area x gill net exposition time (m2 x h); length frequency histograms were built with intervals of 5 cm. The length-weight parameters were estimated with a linear regression after a logarithmic transformation of the data. With the reproductive data we estimated sex ratio, reproduction period and length at first maturity (L50). We captured a total of 1,071 specimens of P. squamosissimus and 156 specimens of C. monoculus. Both species showed higher abundances in 2010, 0.004306 m2 x h and 0.00022 m2 x h, respectively, but this parameter decreased from 2010 to 2013. Standard length ranged between 6.4 and 46.2 cm for P. squamosissimus (20.025.0 cm was the most frequent class), and 7.0 and 38.7 cm for C. monocidus (10.0-15.0 cm was the most frequent class). The length-weight relationships were described by the following equations: log10Wt = -1.8349+3.0899log10Lp and R2= 0.9795 for P. squamosissimus, and log10 Wt = -1.7944+3.0885log10Lp and Wt = 0

  7. How systematic age underestimation can impede understanding of fish population dynamics: Lessons learned from a Lake Superior cisco stock

    USGS Publications Warehouse

    Yule, D.L.; Stockwell, J.D.; Black, J.A.; Cullis, K.I.; Cholwek, G.A.; Myers, J.T.

    2008-01-01

    Systematic underestimation of fish age can impede understanding of recruitment variability and adaptive strategies (like longevity) and can bias estimates of survivorship. We suspected that previous estimates of annual survival (S; range = 0.20-0.44) for Lake Superior ciscoes Coregonus artedi developed from scale ages were biased low. To test this hypothesis, we estimated the total instantaneous mortality rate of adult ciscoes from the Thunder Bay, Ontario, stock by use of cohort-based catch curves developed from commercial gill-net catches and otolith-aged fish. Mean S based on otolith ages was greater for adult females (0.80) than for adult males (0.75), but these differences were not significant. Applying the results of a study of agreement between scale and otolith ages, we modeled a scale age for each otolith-aged fish to reconstruct catch curves. Using modeled scale ages, estimates of S (0.42 for females, 0.36 for males) were comparable with those reported in past studies. We conducted a November 2005 acoustic and midwater trawl survey to estimate the abundance of ciscoes when the fish were being harvested for roe. Estimated exploitation rates were 0.085 for females and 0.025 for males, and the instantaneous rates of fishing mortality were 0.089 for females and 0.025 for males. The instantaneous rates of natural mortality were 0.131 and 0.265 for females and males, respectively. Using otolith ages, we found that strong year-classes at large during November 2005 were caught in high numbers as age-1 fish in previous annual bottom trawl surveys, whereas weak or absent year-classes were not. For decades, large-scale fisheries on the Great Lakes were allowed to operate because ciscoes were assumed to be short lived and to have regular recruitment. We postulate that the collapse of these fisheries was linked in part to a misunderstanding of cisco biology driven by scale-ageing error. ?? Copyright by the American Fisheries Society 2008.

  8. Magnetic Properties of Lake Sediments as a Possible Tool to Improve Estimates of Prehistoric Fluctuations in Fish Population

    NASA Astrophysics Data System (ADS)

    Geiss, C. E.; Oleskewicz, M.; West, D.; Post, D. M.

    2010-12-01

    Alewives are small anadromous fish that spend most of their lives in the ocean, but use small coastal lakes as their spawning grounds. Since many of these fish die after spawning they can supply a significant amount of marine derived nutrients to these lacustrine ecosystems. Over the past decades, however, alewife numbers have declined significantly in Connecticut lakes. We studied the magnetic properties of two Connecticut lakes to investigate whether changes in alewife populations are reflected in the sediment magnetic record and could be used to improve the estimates of prehistoric fluctuations in alewife populations. Since the marine derived nitrogen is enriched in δ15N, nitrogen isotope ratios are used as a proxy for anadromous fish population size. Sediment magnetic properties were characterized through measurements of magnetic susceptibility, anhysteretic remanent magnetization, Isothermal remanent magnetization, coercivity parameters, hysteresis looks and Curie-temperature measurements. We used a paired watershed approach utilizing Bride Lake which has a viable alewife population and nearby Uncas Pond which due to the presence of a waterfall cannot receive anadromous fish. Bride Lake shows prehistoric variations in δ15N, which are also reflected in the sediment magnetic properties. Time periods with high δ15N (high marine nutrient input) are characterized by low ARM/IRM ratios and lower S-ratios, indicating intense dissolution of soft ferrimagnetic minerals and a relative increase in coarse ferrimagnets and a shift to higher coercivity titanomagnetite minerals. Uncas Lake does not show this shift in grain size or magnetic coercivity, suggesting that sediment magnetic properties can assist in the reconstruction of prehistoric alewife populations.

  9. An assessment of oil-spill effects on pink salmon populations following the Exxon Valdez oil spill. Part 2: Adults and escapement

    SciTech Connect

    Maki, A.W.; Brannon, E.J.; Gilbertson, L.G.; Moulton, L.L.; Skalski, J.R.

    1995-12-31

    This paper presents results of a field program designed to monitor the status of wildstock pink salmon populations in Prince William Sound following the Exxon Valdez oil spill. Field counts of spawning salmon were conducted each year from 1989 through 1992 to test for spill effects o the distribution nd abundance of pink salmon adults spawning in selected streams in the southwestern portion of Prince William Sound, including streams from the most heavily oiled areas. Counts of whole-stream and intertidal escapement density were statistically compared for 40 study streams in 1989 and for a subset of those streams in successive years. Measurements of residual hydrocarbons were made from stream-bed sediments to test for correlations with spawning behavior. Adult pink salmon in the postspill years of 1990 and 1991, progeny of the year classes considered most vulnerable to the oil spill, returned in high numbers, with the wildstock spawners exceeding their parent year returns. In 1989, adult returns reflected the relatively weak run for that year with a mean spawner density of 0.68 fish/m{sup 2} in reference streams and 0.69 fish/m{sup 2} in oiled streams. In 1990, mean escapement density for reference streams was 1.40 fish/m{sup 2} and 1.55 fish/m{sup 2} for oiled streams, indicating the strongest run of the four study years. Trends in polycyclic aromatic hydrocarbon (PAH) concentrations for the majority of oiled streams show a general decline from 1989 to background levels by 1990. 45 refs., 14 figs., 5 tabs.

  10. Genomic diversity of cultivable Lactobacillus populations residing in the neonatal and adult gastrointestinal tract.

    PubMed

    Wall, Rebecca; Fitzgerald, Gerald; Hussey, Séamus; Ryan, Tony; Murphy, Brendan; Ross, Paul; Stanton, Catherine

    2007-01-01

    The objective of this study was to investigate the cultivable Lactobacillus population in adult and infant faecal material to identify strains shared across a number of individuals. A range of lactobacilli isolated on Lactobacillus-selective agar from faeces of 16 infants and 11 adults were genetically fingerprinted and further characterized by 16S rRNA gene sequencing. The relatedness of all the Lactobacillus strains isolated to known species was also determined both genetically and phenotypically. This study revealed that the human intestine is initially colonized by only a few (1-2) different cultivable strains whereas in adults the pattern becomes more complex with a higher diversity of strains. The adult samples contained three genetically distinct Lactobacillus strains in some cases, while infant samples generally harboured only one dominant Lactobacillus strain. Moreover, the species in general appeared to differ with Lactobacillus rhamnosus and Lactobacillus casei/paracasei found mainly in adults, whereas Lactobacillus gasseri and Lactobacillus salivarius were more commonly isolated in infant samples. The data reaffirm the differences in Lactobacillus populations both between individual subjects and between the infant and adult, with an overall change in the diversity and complexity from early stages of life to adulthood.

  11. Effect of prehatching weightlessness on adult fish behavior in dynamic environments.

    PubMed

    Hoffman, R B; Boyd, S J; von Baumgarten, R J; Baky, A A

    1978-04-01

    At 16-17 months of age, three groups of fish from the embryonated eggs in the ASTP killifish experiment were subjected to postflight tests consisting of rapidly changing environments. It was found that the group of fish with the least amount of development at orbital insertion (A-32) had a decreased rheotropism for both the moving background and the rotating water current tests when compared to ground control fish. Exposure to parabolic aircraft flight conditions revealed that the A-32 fish were less disoriented during zero gravity periods and were hypersensitive to high-gravity periods. These results suggested a modified vestibular competency due to a 9-d prehatching weightlessness exposure. PMID:305779

  12. Prevalence of Active and Passive Smoking among Adult Population: Findings of a Population-Based Survey in Kerman (KERCADRS), Iran

    PubMed Central

    Salimzadeh, Hamideh; Najafipour, Hamid; Mirzaiepour, Fatemeh; Navadeh, Soodabeh; Shadkam-Farrokhi, Mitra; Mirzazadeh, Ali

    2016-01-01

    Background Smoking is one of the major modifiable risk factors for non-communicable diseases. Our aim was to report the pattern of active and passive smoking using the data collected through a population-base household survey in Kerman, Iran [(KERCADRS) Kerman Coronary Artery Disease Risk Factors Study]. Methods Using a cluster random sampling design, we recruited 5900 adult persons (15-75 years old) into our survey. After consenting, every participant was interviewed by a trained interviewer. The section for smoking included questions about daily (smoking at least one cigarette per day), non-daily, past and passive cigarette smoking as well as the duration of the exposure. We used Kerman population distribution (as the target population) to adjust our estimates using direct standardization method. Findings Overall, 8.3% of study participants (15.5% in men vs. 0.8% in women, P = 0.010) reported themselves as daily smokers and an additional 1.7% (2.9% in men vs. 0.4% in women, P = 0.010) as non-daily smokers. The passive smoking was common in total (27.5%), while women experienced more exposure than men (30.1% vs. 25.0%, P = 0.010). In daily smokers, 3.2% smoked more than 20 cigarettes per day. Among passive smokers, 62.6% were exposed to cigarette smoke more than 6 days per week. Conclusion Smoking is pretty common among adult populations, particularly in men. A majority of tobacco-free young adult women are exposed to passive smoking. Age and gender oriented interventions are required to change this risk pattern in Kerman community to prevent from further smoking related morbidities and mortalities. PMID:27274789

  13. The Contributions of Phonological and Morphological Awareness to Literacy Skills in the Adult Basic Education Population

    ERIC Educational Resources Information Center

    Fracasso, Lucille E.; Bangs, Kathryn; Binder, Katherine S.

    2016-01-01

    The Adult Basic Education (ABE) population consists of a wide range of abilities with needs that may be unique to this set of learners. The purpose of this study was to better understand the relative contributions of phonological decoding and morphological awareness to spelling, vocabulary, and comprehension across a sample of ABE students. In…

  14. HIV/AIDS Misconceptions among Latinos: Findings from a Population-Based Survey of California Adults

    ERIC Educational Resources Information Center

    Ritieni, Assunta; Moskowitz, Joel; Tholandi, Maya

    2008-01-01

    Misconceptions about HIV/AIDS among Latino adults (N=454) in California were examined using data from a population-based telephone survey conducted in 2000. Common misconceptions concerning modes of HIV transmission included transmission via mosquito or animal bite (64.1%), public facilities (48.3%), or kissing someone on the cheek (24.8%). A…

  15. Participation in Adult Education: Current Population Survey, May 1984 [machine-readable data file].

    ERIC Educational Resources Information Center

    Bureau of the Census (DOC), Washington, DC. Data User Services Div.

    The "Participation in Adult Education" machine-readable data file (MRDF) is prepared triennially for the Center for Education Statistics (CES) by the Bureau of the Census, as a supplement to its regular "Current Population Survey" (sponsored by the Bureau of Labor Statistics). Previous specialized surveys in this series have been conducted in…

  16. A Meta-Analysis of Dunn and Dunn Model Correlational Research with Adult Populations

    ERIC Educational Resources Information Center

    Mangino, Christine

    2004-01-01

    The purpose of this investigation was to conduct a quantitative synthesis of correlational research that focused on the Dunn and Dunn Learning-Style Model and was concerned with adult populations. A total of 8,661 participants from the 47 original investigations provided 386 individual effect sizes for this meta-analysis. The mean effect size was…

  17. Population structure of the fish pathogen Flavobacterium psychrophilum at whole-country and model river levels in Japan.

    PubMed

    Fujiwara-Nagata, Erina; Chantry-Darmon, Céline; Bernardet, Jean-François; Eguchi, Mitsuru; Duchaud, Eric; Nicolas, Pierre

    2013-01-01

    The bacterium Flavobacterium psychrophilum is a serious problem for salmonid farming worldwide. This study investigates by multilocus sequence typing (MLST) the population structure of this pathogen in Japan where it is also a major concern for ayu, a popular game fish related to salmoniforms. A total of 34 isolates collected across the country and 80 isolates sampled in a single model river by electrofishing were genotyped. The data accounting for 15 fish species allowed identifying 35 distinct sequence types (ST) in Japan. These ST are distinct from those reported elsewhere, except for some ST found in rainbow trout and coho salmon, two fish that have been the subject of intensive international trade. The pattern of polymorphism is, however, strikingly similar across geographical scales (model river, Japan, world) in terms of the fraction of molecular variance linked to the fish host (~50%) and of pairwise nucleotide diversity between ST (~5 Kbp(-1)). These observations go against the hypothesis of a recent introduction of F. psychrophilum in Japan. Two findings were made that are important for disease control: 1) at least two independent F. psychrophilum lineages infect ayu and 2) co-infections of the same individual fish by different strains occur. PMID:23682575

  18. Population structure of the fish pathogen Flavobacterium psychrophilum at whole-country and model river levels in Japan.

    PubMed

    Fujiwara-Nagata, Erina; Chantry-Darmon, Céline; Bernardet, Jean-François; Eguchi, Mitsuru; Duchaud, Eric; Nicolas, Pierre

    2013-05-17

    The bacterium Flavobacterium psychrophilum is a serious problem for salmonid farming worldwide. This study investigates by multilocus sequence typing (MLST) the population structure of this pathogen in Japan where it is also a major concern for ayu, a popular game fish related to salmoniforms. A total of 34 isolates collected across the country and 80 isolates sampled in a single model river by electrofishing were genotyped. The data accounting for 15 fish species allowed identifying 35 distinct sequence types (ST) in Japan. These ST are distinct from those reported elsewhere, except for some ST found in rainbow trout and coho salmon, two fish that have been the subject of intensive international trade. The pattern of polymorphism is, however, strikingly similar across geographical scales (model river, Japan, world) in terms of the fraction of molecular variance linked to the fish host (~50%) and of pairwise nucleotide diversity between ST (~5 Kbp(-1)). These observations go against the hypothesis of a recent introduction of F. psychrophilum in Japan. Two findings were made that are important for disease control: 1) at least two independent F. psychrophilum lineages infect ayu and 2) co-infections of the same individual fish by different strains occur.

  19. An adult osteopetrosis model in medaka reveals the importance of osteoclast function for bone remodeling in teleost fish.

    PubMed

    To, Thuy Thanh; Witten, Paul Eckhard; Huysseune, Ann; Winkler, Christoph

    2015-12-01

    Osteoclasts play important roles during bone growth and in maintaining bone health and bone homeostasis. Dysfunction or lack of osteoclasts leads to increased bone mass and osteopetrosis phenotypes in mouse and human. Here we report a severe osteopetrosis-like phenotype in transgenic medaka fish, in which membrane bound EGFP (mEGFP) was expressed in osteoclasts under control of the cathepsin K promoter (ctsk:mEGFP). In contrast to reporter lines with GFP expression in the cytoplasm of osteoclasts, adult fish of the mEGFP line developed bone defects indicative for an osteoclast dysfunction. Activity of tartrate-resistant acid phosphatase (TRAP) was down-regulated and excess bone was observed in most parts of the skeleton. The osteopetrotic phenotype was particularly obvious at the neural and haemal arches that failed to increase their volume in growing fish. Excess bone caused severe constriction of the spinal cord and the ventral aorta. The continuation of tooth development and the failure to shed teeth resulted in severe hyperdontia. Interestingly, at the vertebral column vertebral body arches displayed a severe osteopetrosis, while vertebral centra had no or only a mild osteopetrotic phenotype. This confirms previous reports from cichlids that, different from the arches, allometric growth of fish vertebral centra initially does not depend on the action of osteoclasts. Independent developmental mechanism that shapes arches and vertebral centra can also lend support to the hypothesis that vertebral centra and arches function as independent developmental modules. Together, this medaka osteopetrosis model confirms the importance of proper osteoclast function during normal skeletal development in teleost fish that requires bone modeling and remodeling.

  20. Distribution and abundance of fish populations in Harike wetland--a Ramsar site in India.

    PubMed

    Dua, Anish; Parkash, Chander

    2009-03-01

    Harike wetland was declared a Ramsar site in 1990. It is located at the confluence of two major rivers of Indus rivers system, the Beas and the Sutlej, but was never explored extensively for its existing fish biodiversity. Earlier only 27 fish species of commercial value were reported from the wetland. Acknowledging its importance for rich diversity fish assemblages in seven different reaches of Harike wetland were studied to determine their abundance and distribution. 61 fish species of 35 genera were recorded from Harike wetland during the present study. Cirrihinus mrigala and Cyprinus carpio belonging to family Cyprinidae were the dominant fish species. Lake and Riyasat having many microhabitats supported highest diversity of fishes (60 and 56 respectively) followed by Beas (20) Sutlej (14), Confluence (12), Reservoir (9) and Downstream (8). Among the IUCN designated threatened species, 1 Critically Endangered, 4 Endangered and 13 Vulnerable fish species of India are found in Harike wetland. Species diversity index, dominance, evenness and catch per unit effort were calculated to ascertain the fish distribution in Harike wetland. PMID:20121026

  1. Computer program for sample sizes required to determine disease incidence in fish populations

    USGS Publications Warehouse

    Ossiander, Frank J.; Wedemeyer, Gary

    1973-01-01

    A computer program is described for generating the sample size tables required in fish hatchery disease inspection and certification. The program was designed to aid in detection of infectious pancreatic necrosis (IPN) in salmonids, but it is applicable to any fish disease inspection when the sampling plan follows the hypergeometric distribution.

  2. Fisheries-induced neutral and adaptive evolution in exploited fish populations and consequences for their adaptive potential

    PubMed Central

    Marty, Lise; Dieckmann, Ulf; Ernande, Bruno

    2015-01-01

    Fishing may induce neutral and adaptive evolution affecting life-history traits, and molecular evidence has shown that neutral genetic diversity has declined in some exploited populations. Here, we theoretically study the interplay between neutral and adaptive evolution caused by fishing. An individual-based eco-genetic model is devised that includes neutral and functional loci in a realistic ecological setting. In line with theoretical expectations, we find that fishing induces evolution towards slow growth, early maturation at small size and higher reproductive investment. We show, first, that the choice of genetic model (based on either quantitative genetics or gametic inheritance) influences the evolutionary recovery of traits after fishing ceases. Second, we analyse the influence of three factors possibly involved in the lack of evolutionary recovery: the strength of selection, the effect of genetic drift and the loss of adaptive potential. We find that evolutionary recovery is hampered by an association of weak selection differentials with reduced additive genetic variances. Third, the contribution of fisheries-induced selection to the erosion of functional genetic diversity clearly dominates that of genetic drift only for the traits related to maturation. Together, our results highlight the importance of taking into account population genetic variability in predictions of eco-evolutionary dynamics. PMID:25667602

  3. Mercury levels and estimated total daily intakes for children and adults from an electronic waste recycling area in Taizhou, China: Key role of rice and fish consumption.

    PubMed

    Tang, Wei; Cheng, Jinping; Zhao, Wenchang; Wang, Wenhua

    2015-08-01

    In order to assess the potential health risks of Hg pollution, total mercury (T-Hg) and methyl mercury (MeHg) concentrations were determined in air, dust, surface soil, crops, poultry, fish and human hair samples from an electronic waste (e-waste) recycling area in Taizhou, China. High concentrations of T-Hg and MeHg were found in these multiple matrices, and the mean concentration was 30.7 ng/m(3) of T-Hg for atmosphere samples, 3.1 μg/g of T-Hg for soil, 37.6 μg/g of T-Hg for dust, 20.3 ng/g of MeHg for rice and 178.1 ng/g of MeHg for fish, suggesting that the e-waste recycling facility was a significant source of Hg. The inorganic Hg (I-Hg) levels (0.84 μg/g) in hair samples of e-waste workers were much higher than that in the reference samples. Pearson's correlation coefficients showed that strong positive correlations (p<0.01) between hair I-Hg and time staying in industrial area (r=0.81) and between MeHg and fish consumption frequency (r=0.91), imply that workers were mainly exposed to Hg vapor through long-time inhalation of contaminated air and dust, while other population mainly exposed to MeHg through high-frequency fish consumption. The estimated daily intakes of Hg showed that dietary intake was the major Hg exposure source, and Hg intakes from rice and fish were significantly higher than from any other foods. The estimated total daily intakes (TDIs) of MeHg for both children (696.8 ng/(kg·day)) and adults (381.3 ng/(kg·day)) greatly exceeded the dietary reference dose (RfD) of 230 ng/(kg·day), implying greater health risk for humans from Hg exposures around e-waste recycling facilities.

  4. Nutrition Considerations for the Growing Population of Older Adults With Diabetes

    PubMed Central

    Stanley, Kathleen

    2014-01-01

    In Brief The growing older adult population and its higher incidence of diabetes are creating demands on health care providers to address the special needs of these patients. Because nutrition is essential to the proper treatment and self-management of diabetes, clinicians must develop and adopt various strategies to address some of the common nutritional, lifestyle, and self-management barriers that older adults face. Nutrition assessments of older adults with diabetes should be comprehensive, with attention to each patient’s unique nutritional needs. Constructing a realistic nutrition care plan is essential for success. This article addresses some of the key nutrition-related aspects of diabetes self-care in older adults with diabetes. PMID:26246753

  5. Population genetic studies revealed local adaptation in a high gene-flow marine fish, the small yellow croaker (Larimichthys polyactis).

    PubMed

    Wang, Le; Liu, Shufang; Zhuang, Zhimeng; Guo, Liang; Meng, Zining; Lin, Haoran

    2013-01-01

    The genetic differentiation of many marine fish species is low. Yet local adaptation may be common in marine fish species as the vast and changing marine environment provides more chances for natural selection. Here, we used anonymous as well as known protein gene linked microsatellites and mitochondrial DNA to detect the population structure of the small yellow croaker (Larimichthys polyactis) in the Northwest Pacific marginal seas. Among these loci, we detected at least two microsatellites, anonymous H16 and HSP27 to be clearly under diversifying selection in outlier tests. Sequence cloning and analysis revealed that H16 was located in the intron of BAHCC1 gene. Landscape genetic analysis showed that H16 mutations were significantly associated with temperature, which further supported the diversifying selection at this locus. These marker types presented different patterns of population structure: (i) mitochondrial DNA phylogeny showed no evidence of genetic divergence and demonstrated only one glacial linage; (ii) population differentiation using putatively neutral microsatellites presented a pattern of high gene flow in the L. polyactis. In addition, several genetic barriers were identified; (iii) the population differentiation pattern revealed by loci under diversifying selection was rather different from that revealed by putatively neutral loci. The results above suggest local adaptation in the small yellow croaker. In summary, population genetic studies based on different marker types disentangle the effects of demographic history, migration, genetic drift and local adaptation on population structure and also provide valuable new insights for the design of management strategies in L. polyactis.

  6. Population sizes and growth pressure responses of intestinal microfloras of deep-sea fish retrieved from the abyssal zone.

    PubMed

    Yano, Y; Nakayama, A; Yoshida, K

    1995-12-01

    The intestinal floras of seven deep-sea fish retrieved at depths of from 3,200 to 5,900 m were examined for population sizes and growth responses to pressure. Large populations of culturable bacteria, ranging from 1.1 x 10(sup6) to 3.6 x 10(sup8) cells per ml of contents, were detected when samples were incubated at conditions characteristic of those of the deep sea. Culturable cell counts at in situ pressures were greater than those at atmospheric pressure in all samples. Most of the strains isolated by the spread-plating method at atmospheric pressure later proved barophilic. Barophilic bacteria were the predominant inhabitants of the abyssal fish intestines. PMID:16535199

  7. Genetic signature of recent glaciation on populations of a near-shore marine fish species (Syngnathus leptorhynchus).

    PubMed

    Wilson, A B

    2006-06-01

    Continental glaciation has played a major role in shaping the present-day phylogeography of freshwater and terrestrial species in the Northern Hemisphere. Recent work suggests that coastal glaciation during ice ages may have also had a significant impact on marine species. The bay pipefish, Syngnathus leptorhynchus, is a near-shore Pacific coast fish species with an exceptionally wide latitudinal distribution, ranging from Bahia Santa Maria, Baja California to Prince William Sound, Alaska. Survey data indicate that S. leptorhynchus is experiencing a range expansion at the northern limit of its range, consistent with colonization from southern populations. The present study uses six novel microsatellite markers and mitochondrial DNA (mtDNA) sequence data to study the present-day population genetic structure of four coastal populations of S. leptorhynchus. Deficits in mtDNA and nuclear DNA diversity in northern populations from regions glaciated during the last glacial maximum (LGM) [c. 18 000 years before present (bp)] suggest that these populations were effected by glacial events. Direct estimates of population divergence times derived from both isolation and isolation-with-migration models of evolution are also consistent with a postglacial phylogenetic history of populations north of the LGM. Sequence data further indicate that a population at the southern end of the species range has been separated from the three northern populations since long before the last interglacial event (c. 130 000 years bp), suggesting that topographical features along the Pacific coast may maintain population separation in regions unimpacted by coastal glaciation.

  8. Fish oil–derived n–3 PUFA therapy increases muscle mass and function in healthy older adults1

    PubMed Central

    Smith, Gordon I; Julliand, Sophie; Reeds, Dominic N; Sinacore, David R; Klein, Samuel; Mittendorfer, Bettina

    2015-01-01

    Background: Age-associated declines in muscle mass and function are major risk factors for an impaired ability to carry out activities of daily living, falls, prolonged recovery time after hospitalization, and mortality in older adults. New strategies that can slow the age-related loss of muscle mass and function are needed to help older adults maintain adequate performance status to reduce these risks and maintain independence. Objective: We evaluated the efficacy of fish oil–derived n–3 (ω-3) PUFA therapy to slow the age-associated loss of muscle mass and function. Design: Sixty healthy 60–85-y-old men and women were randomly assigned to receive n–3 PUFA (n = 40) or corn oil (n = 20) therapy for 6 mo. Thigh muscle volume, handgrip strength, one-repetition maximum (1-RM) lower- and upper-body strength, and average power during isokinetic leg exercises were evaluated before and after treatment. Results: Forty-four subjects completed the study [29 subjects (73%) in the n–3 PUFA group; 15 subjects (75%) in the control group]. Compared with the control group, 6 mo of n–3 PUFA therapy increased thigh muscle volume (3.6%; 95% CI: 0.2%, 7.0%), handgrip strength (2.3 kg; 95% CI: 0.8, 3.7 kg), and 1-RM muscle strength (4.0%; 95% CI: 0.8%, 7.3%) (all P < 0.05) and tended to increase average isokinetic power (5.6%; 95% CI: −0.6%, 11.7%; P = 0.075). Conclusion: Fish oil–derived n–3 PUFA therapy slows the normal decline in muscle mass and function in older adults and should be considered a therapeutic approach for preventing sarcopenia and maintaining physical independence in older adults. This study was registered at clinicaltrials.gov as NCT01308957. PMID:25994567

  9. Phenotypic plasticity in growth and fecundity induced by strong population fluctuations affects reproductive traits of female fish.

    PubMed

    Karjalainen, Juha; Urpanen, Olli; Keskinen, Tapio; Huuskonen, Hannu; Sarvala, Jouko; Valkeajärvi, Pentti; Marjomäki, Timo J

    2016-02-01

    Fish are known for their high phenotypic plasticity in life-history traits in relation to environmental variability, and this is particularly pronounced among salmonids in the Northern Hemisphere. Resource limitation leads to trade-offs in phenotypic plasticity between life-history traits related to the reproduction, growth, and survival of individual fish, which have consequences for the age and size distributions of populations, as well as their dynamics and productivity. We studied the effect of plasticity in growth and fecundity of vendace females on their reproductive traits using a series of long-term incubation experiments. The wild parental fish originated from four separate populations with markedly different densities, and hence naturally induced differences in their growth and fecundity. The energy allocation to somatic tissues and eggs prior to spawning served as a proxy for total resource availability to individual females, and its effects on offspring survival and growth were analyzed. Vendace females allocated a rather constant proportion of available energy to eggs (per body mass) despite different growth patterns depending on the total resources in the different lakes; investment into eggs thus dictated the share remaining for growth. The energy allocation to eggs per mass was higher in young than in old spawners and the egg size and the relative fecundity differed between them: Young females produced more and smaller eggs and larvae than old spawners. In contrast to earlier observations of salmonids, a shortage of maternal food resources did not increase offspring size and survival. Vendace females in sparse populations with ample resources and high growth produced larger eggs and larvae. Vendace accommodate strong population fluctuations by their high plasticity in growth and fecundity, which affect their offspring size and consequently their recruitment and productivity, and account for their persistence and resilience in the face of high

  10. Comparison of facial morphologies between adult Chinese and Houstonian Caucasian populations using three-dimensional imaging.

    PubMed

    Wirthlin, J; Kau, C H; English, J D; Pan, F; Zhou, H

    2013-09-01

    The objective of this study was to compare the facial morphologies of an adult Chinese population to a Houstonian white population. Three-dimensional (3D) images were acquired via a commercially available stereophotogrammetric camera system, 3dMDface™. Using the system, 100 subjects from a Houstonian population and 71 subjects from a Chinese population were photographed. A complex mathematical algorithm was performed to generate a composite facial average (one for males and one for females) for each subgroup. The computer-generated facial averages were then superimposed based on a previously validated superimposition method. The facial averages were evaluated for differences. Distinct facial differences were evident between the subgroups evaluated. These areas included the nasal tip, the peri-orbital area, the malar process, the labial region, the forehead, and the chin. Overall, the mean facial difference between the Chinese and Houstonian female averages was 2.73±2.20mm, while the difference between the Chinese and Houstonian males was 2.83±2.20mm. The percent similarity for the female population pairings and male population pairings were 10.45% and 12.13%, respectively. The average adult Chinese and Houstonian faces possess distinct differences. Different populations and ethnicities have different facial features and averages that should be considered in the planning of treatment.

  11. Body Mass Index in Adults with Intellectual Disability: Distribution, Associations and Service Implications--A Population-Based Prevalence Study

    ERIC Educational Resources Information Center

    Bhaumik, S.; Watson, J. M.; Thorp, C. F.; Tyrer, F.; McGrother, C. W.

    2008-01-01

    Background: Previous studies of weight problems in adults with intellectual disability (ID) have generally been small or selective and given conflicting results. The objectives of our large-scale study were to identify inequalities in weight problems between adults with ID and the general adult population, and to investigate factors associated…

  12. Increasing opportunities for the productive engagement of older adults: a response to population aging.

    PubMed

    Gonzales, Ernest; Matz-Costa, Christina; Morrow-Howell, Nancy

    2015-04-01

    "Productive aging" puts forward the fundamental view that the capacity of older adults must be better developed and utilized in activities that make economic contributions to society-working, caregiving, volunteering. It is suggested that productive engagement can lead to multiple positive ends: offsetting fiscal strains of a larger older population, contributing to the betterment of families and civil society, and maintaining the health and economic security of older adults. Advocates claim that outdated social structures and discriminatory behaviors limit participation of older adults in these important social roles as well as prevent the optimization of outcomes for older adults, families, and society. We ask two important questions: (a) How can we shape policies and programs to optimally engage the growing resources of an aging population for the sake of society and older adults themselves? and (b) How can policies pertaining to productive engagement reduce health and economic disparities? We answer these questions by first describing the current state of engagement in each of the three productive activities and summarize some current policies and programs that affect engagement. Next we highlight challenges that cross-cut productive engagement. Finally, we provide policy recommendations to address these challenges. PMID:26035601

  13. Only a small population of adult Sertoli cells actively proliferates in culture.

    PubMed

    Kulibin, Andrey Yu; Malolina, Ekaterina A

    2016-10-01

    Adult mammalian Sertoli cells (SCs) have been considered to be quiescent terminal differentiated cells for many years, but recently, proliferation of adult SCs was demonstrated in vitro and in vivo We further examined mouse SC behavior in culture and found that there are two populations of adult SCs. The first population is SCs from seminiferous tubules that hardly proliferate in vitro The second population is small and consists of SCs with atypical nuclear morphology from the terminal segments of seminiferous tubules, a transitional zone (TZ). TZ SCs multiply in culture and form colonies, display mixture of mature and immature SC characteristics, and generate cord-like structures in a collagen matrix. The specific features of TZ SCs are ACTA2 expression in vitro and DMRT1 low levels in vivo and in vitro Although the in vivo function of TZ SCs still remains unclear, this finding has significant implications for our understanding of SC differentiation and functioning in adult mammals. PMID:27512121

  14. The dynamics of fish populations in the Palancar stream,a small tributary of the river Guadalquivir, Spain

    NASA Astrophysics Data System (ADS)

    Bravo, Ramón; Soriguer, Mila C.; Villar, Noelia; Hernando, José A.

    2001-02-01

    The relationship between flooding and changes in the size distribution of fish populations in the Palancar stream confirms observations in other rivers. On average, density decreased by 36.2 % and biomass increased by 14.5 %, passing from a period of severe drought to one of heavier than normal rains. Precipitation is the most important of the many factors affecting the populations of the Palancar stream; the most evident changes all occurred after the drought. During the drought period, the marked seasonal fluctuation in flow was the most important factor regulating the population dynamics. Fish density and biomass varied in proportion to the water volume. During the rainy period, the studied section of the river was found to be an important reproduction and nursery area, with juveniles and individuals of reproduction age dominating. The presence of Micropterus salmoides, an introduced piscivorous species, is another factor affecting the population dynamics in the Palancar stream. The observed absence of age 0+ individuals of the dominant populations is considered a direct effect of predation.

  15. Modeling responses of large-river fish populations to global climate change through downscaling and incorporation of predictive uncertainty

    USGS Publications Warehouse

    Wildhaber, Mark L.; Wikle, Christopher K.; Anderson, Christopher J.; Franz, Kristie J.; Moran, Edward H.; Dey, Rima; Mader, Helmut; Kraml, Julia

    2012-01-01

    Climate change operates over a broad range of spatial and temporal scales. Understanding its effects on ecosystems requires multi-scale models. For understanding effects on fish populations of riverine ecosystems, climate predicted by coarse-resolution Global Climate Models must be downscaled to Regional Climate Models to watersheds to river hydrology to population response. An additional challenge is quantifying sources of uncertainty given the highly nonlinear nature of interactions between climate variables and community level processes. We present a modeling approach for understanding and accomodating uncertainty by applying multi-scale climate models and a hierarchical Bayesian modeling framework to Midwest fish population dynamics and by linking models for system components together by formal rules of probability. The proposed hierarchical modeling approach will account for sources of uncertainty in forecasts of community or population response. The goal is to evaluate the potential distributional changes in an ecological system, given distributional changes implied by a series of linked climate and system models under various emissions/use scenarios. This understanding will aid evaluation of management options for coping with global climate change. In our initial analyses, we found that predicted pallid sturgeon population responses were dependent on the climate scenario considered.

  16. What radiation dose does the FISH translocation assay measure in cases of incorporated radionuclides for the Southern Urals populations?

    PubMed

    Ainsbury, Elizabeth A; Moquet, Jayne; Rothkamm, Kai; Darroudi, Firouz; Vozilova, Alexandra; Degteva, Marina; Azizova, Tamara V; Lloyd, David C; Harrison, John

    2014-06-01

    The fluorescence in situ hybridisation (FISH) technique is now well established for retrospective dosimetry in cases of external radiation exposure that occurred many years ago. However, the question remains as to whether FISH provides valid estimates of cumulative red bone marrow radiation doses in cases of incorporation of radionuclides or combined external and internal exposures. This question has arisen in connection with the interpretation of results of dose assessments for epidemiological studies of plutonium workers at the Russian Mayak plant and of members of the public exposed to strontium radioisotopes and external radiation as a result of discharges from Mayak to the Techa River. Exposures to penetrating external radiation result in fairly uniform irradiation of body tissues, and hence similar doses to all tissues, for which FISH dosimetry can provide a reliable measure of this whole body dose. However, intakes of radionuclides into the body by inhalation or ingestion may result in retention in specific organs and tissues, so that the distribution of dose is highly heterogeneous. For radionuclides emitting short-range radiations (e.g. alpha particles), this heterogeneity can apply to dose delivery within tissues and between cells within tissues. In this paper, an attempt is made to address the question of what FISH measures in such circumstances by considering evidence regarding the origin and lifetime dynamics of lymphocyte subsets in the human body in relation to the localised delivery of dose from the internal emitters (90)Sr and (239)Pu, which are of particular interest for the Southern Urals Mayak and Techa River populations, and for which most evidence is available in these populations. It is concluded that the FISH translocation assay can be usefully applied for detecting internal and combined external gamma and internal doses from internally deposited (90)Sr, albeit with fairly large uncertainties. The same may be true of (239)Pu, as well as

  17. Pathogens associated with native and exotic trout populations in Shenandoah National Park and the relationships to fish stocking practices

    USGS Publications Warehouse

    Panek, Frank M.; Atkinson, James; Coll, John

    2008-01-01

    Restrictive fish stocking policies in National Parks were developed as early as 1936 in order to preserve native fish assemblages and historic genetic diversity. Despite recent efforts to understand the effects of non-native or exotic fish introductions, park managers have limited information regarding the effects of these introductions on native fish communities. Shenandoah National Park was established in 1936 and brook trout (Salvelinus fontinalis) restoration within selected streams in the park began in 1937 in collaboration with the Virginia Department of Game and Inland Fisheries (VDGIF). An analysis of tissue samples from brook, brown (Salmo trutta), and rainbow trout (Oncorhynchus mykiss) from 29 streams within the park from 1998–2002 revealed the presence of Renibacterium salmoninarum, Yersinia ruckeri, and infectious pancreatic necrosis virus (IPNv). In order to investigate the relationships of the occurrence of fish pathogens with stocking histories we classified the streams into three categories: 1) streams with no record of stocking, 2) streams that are known to have been stocked historically, and 3) streams that were historically stocked within the park and continue to be stocked downstream of the park boundary. The occurrences of pathogens were summarized relative to this stocking history. Renibacterium salmoninarum, the causative agent of bacterial kidney disease, was the most prevalent pathogen found, occurring in all three species and stream stocking categories, and appears to be endemic to the park. Two other pathogens, Yersinia ruckeri and infectious pancreatic necrosis virus were also described from brook trout populations within the park. IPNv was only found in brook trout populations in streams with prior stocking histories. Yersinia ruckeri was only found in brook trout in steams that have never been stocked and like R. salmoninarum, is likely endemic.

  18. Partial Characterization of the Sox2+ Cell Population in an Adult Murine Model of Digit Amputation

    PubMed Central

    Agrawal, Vineet; Siu, Bernard F.; Chao, Hsu; Hirschi, Karen K.; Raborn, Eric; Johnson, Scott A.; Tottey, Stephen; Hurley, Katherine B.; Medberry, Chris J.

    2012-01-01

    Tissue regeneration in response to injury in adult mammals is generally limited to select tissues. Nonmammalian species such as newts and axolotls undergo regeneration of complex tissues such as limbs and digits via recruitment and accumulation of local and circulating multipotent progenitors preprogrammed to recapitulate the missing tissue. Directed recruitment and activation of progenitor cells at a site of injury in adult mammals may alter the default wound-healing response from scar tissue toward regeneration. Bioactive molecules derived from proteolytic degradation of extracellular matrix (ECM) proteins have been shown to recruit a variety of progenitor cells in vitro and in vivo to the site of injury. The present study further characterized the population of cells accumulating at the site of injury after treatment with ECM degradation products in a well-established model of murine digit amputation. After a mid-second phalanx digit amputation in 6–8-week-old adult mice, treatment with ECM degradation products resulted in the accumulation of a heterogeneous population of cells, a subset of which expressed the transcription factor Sox2, a marker of pluripotent and adult progenitor cells. Sox2+ cells were localized lateral to the amputated P2 bone and coexpressed progenitor cell markers CD90 and Sca1. Transgenic Sox2 eGFP/+ and bone marrow chimeric mice showed that the bone marrow and blood circulation did not contribute to the Sox2+ cell population. The present study showed that, in addition to circulating progenitor cells, resident tissue-derived cells also populate at the site of injury after treatment with ECM degradation products. Although future work is necessary to determine the contribution of Sox2+ cells to functional tissue at the site of injury, recruitment and/or activation of local tissue-derived cells may be a viable approach to tissue engineering of more complex tissues in adult mammals. PMID:22530556

  19. EFFECTS OF SEASONAL AND WATER QUALITY PARAMETERS ON OYSTERS (CRASSOSTREA VIRGINICA) AND ASSOCIATED FISH POPULATIONS.

    EPA Science Inventory

    Influence of water quality and seasonal changes on disease prevalence and intensity of Perkinsus marinus, gonadal condition, recruitment potential, growth of caged juvenile oysters, and habitat suitability of reefs for fishes and macrobenthic invertebrates were measured in Callos...

  20. Reduced Spill at Hydropower Dams: Opportunities for More Generation and Increased Fish Population

    SciTech Connect

    Coutant, Charles C; Mann, Roger; Sale, Michael J

    2006-09-01

    This report indicates that reduction of managed spill at hydropower dams can speed implementation of technologies for fish protection and achieve economic goals. Spill of water over spillways is managed in the Columbia River basin to assist downstream-migrating juvenile salmon, and is generally believed to be the most similar to natural migration, benign and effective passage route; other routes include turbines, intake screens with bypasses, and surface bypasses. However, this belief may be misguided, because spill is becoming recognized as less than natural, with deep intakes below normal migration depths, and likely causing physical damages from severe shear on spillways, high turbulence in tail waters, and collisions with baffle blocks that lead to disorientation and predation. Some spillways induce mortalities comparable to turbines. Spill is expensive in lost generation, and controversial. Fish-passage research is leading to more fish-friendly turbines, screens and bypasses that are more effective and less damaging, and surface bypasses that offer passage of more fish per unit water volume than does spill (leaving more water for generation). Analyses by independent economists demonstrated that goals of increased fish survival over the long term and net gain to the economy can be obtained by selectively reducing spill and diverting some of the income from added power generation to research, development, and installation of fish-passage technologies. Such a plan would selectively reduce spill when and where least damaging to fish, increase electricity generation using the water not spilled and use innovative financing to direct monetary gains to improving fish passage.

  1. How many steps/day are enough? For older adults and special populations

    PubMed Central

    2011-01-01

    Older adults and special populations (living with disability and/or chronic illness that may limit mobility and/or physical endurance) can benefit from practicing a more physically active lifestyle, typically by increasing ambulatory activity. Step counting devices (accelerometers and pedometers) offer an opportunity to monitor daily ambulatory activity; however, an appropriate translation of public health guidelines in terms of steps/day is unknown. Therefore this review was conducted to translate public health recommendations in terms of steps/day. Normative data indicates that 1) healthy older adults average 2,000-9,000 steps/day, and 2) special populations average 1,200-8,800 steps/day. Pedometer-based interventions in older adults and special populations elicit a weighted increase of approximately 775 steps/day (or an effect size of 0.26) and 2,215 steps/day (or an effect size of 0.67), respectively. There is no evidence to inform a moderate intensity cadence (i.e., steps/minute) in older adults at this time. However, using the adult cadence of 100 steps/minute to demark the lower end of an absolutely-defined moderate intensity (i.e., 3 METs), and multiplying this by 30 minutes produces a reasonable heuristic (i.e., guiding) value of 3,000 steps. However, this cadence may be unattainable in some frail/diseased populations. Regardless, to truly translate public health guidelines, these steps should be taken over and above activities performed in the course of daily living, be of at least moderate intensity accumulated in minimally 10 minute bouts, and add up to at least 150 minutes over the week. Considering a daily background of 5,000 steps/day (which may actually be too high for some older adults and/or special populations), a computed translation approximates 8,000 steps on days that include a target of achieving 30 minutes of moderate-to-vigorous physical activity (MVPA), and approximately 7,100 steps/day if averaged over a week. Measured directly and

  2. [Obesity in adults: a population based study in a small town in South of Brazil, 2005].

    PubMed

    Sarturi, Juliana Barbosa; das Neves, Janaina; Peres, Karen Glazer

    2010-01-01

    Changes in nutritional pattern in Brazilian population have been observed mainly in relation to obesity increase. This study aims to estimate the prevalence of obesity and associated factors in adult population in Santo Angelo, Rio Grande do Sul State, 2005. A cross sectional study was carried out involving adult subjects from 20 to 59 years old (n=434), of both sexes. People with Body Mass Index equal to or higher than 30 kg/m(2) were considered obese. A questionnaire was applied to collect data related to socioeconomic, demographic, and behavioral conditions. The multiple logistic regression analysis was performed to identify the associated factors. The response rate was 95.0% and the prevalence of obesity was equal to 16.6% (CI 95% 13.120.1). Presence of obesity was positively associated with lack of physical activity, none feeding habits care, and some individuals that mentioned current health problems regardless of sex. The prevalence of obesity found was similar to other Brazilian population based studies. The results may support planning and implementing prevention actions as well as obesity control in adult population taking into account the relevant details of a small size town.

  3. AHR-related activities in a creosote-adapted population of adult atlantic killifish, Fundulus heteroclitus, two decades post-EPA superfund status at the Atlantic Wood Site, Portsmouth, VA USA.

    PubMed

    Wojdylo, Josephine V; Vogelbein, Wolfgang; Bain, Lisa J; Rice, Charles D

    2016-08-01

    Atlantic killifish, Fundulus heteroclitus, are adapted to creosote-based PAHs at the US EPA Superfund site known as Atlantic Wood (AW) on the southern branch of the Elizabeth River, VA USA. Subsequent to the discovery of the AW population in the early 1990s, these fish were shown to be recalcitrant to CYP1A induction by PAHs under experimental conditions, and even to the time of this study, killifish embryos collected from the AW site are resistant to developmental deformities typically associated with exposure to PAHs in reference fish. Historically, however, 90 +% of the adult killifish at this site have proliferative hepatic lesions including cancer of varying severity. Several PAHs at this site are known to be ligands for the aryl hydrocarbon receptor (AHR). In this study, AHR-related activities in AW fish collected between 2011 and 2013 were re-examined nearly 2 decades after first discovery. This study shows that CYP1A mRNA expression is three-fold higher in intestines of AW killifish compared to a reference population. Using immunohistochemistry, CYP1A staining in intestines was uniformly positive compared to negative staining in reference fish. Livers of AW killifish were examined by IHC to show that CYP1A and AHR2 protein expression reflect lesions-specific patterns, probably representing differences in intrinsic cellular physiology of the spectrum of proliferative lesions comprising the hepatocarcinogenic process. We also found that COX2 mRNA expression levels were higher in AW fish livers compared to those in the reference population, suggesting a state of chronic inflammation. Overall, these findings suggest that adult AW fish are responsive to AHR signaling, and do express CYP1A and AHR2 proteins in intestines at a level above what was observed in the reference population. PMID:27262937

  4. Dietary intake and food contributors of polyphenols in adults and elderly adults of Sao Paulo: a population-based study.

    PubMed

    Miranda, A M; Steluti, J; Fisberg, R M; Marchioni, D M

    2016-03-28

    A comprehensive estimation of polyphenol intake is needed to gain a better understanding of the association between polyphenol-rich food intake and the potential effects of this intake on chronic diseases. The aim of this study was to estimate the intake of polyphenols and the major dietary contributors in the population of Sao Paulo. Data were obtained from the Health Survey-São Paulo (ISA-Capital 2008) and were reported for 1103 adults and elderly adults. Food intake was estimated by one 24-h dietary recall (24HR). Polyphenol intake was calculated by matching food consumption data from the 24HR with the polyphenol content in foods listed in the Phenol-Explorer database. The mean total intake of polyphenols was 377·5 (se 15·3) mg/d. The main polyphenol classes were phenolic acids (284·8 (se 15·9) mg/d) and flavonoids (54·6 (se 3·5) mg/d). Intakes were higher in the elderly adults than in other adults (P<0·001) and higher in individuals with lower educational level (P=0·01) and current smokers (P=0·02). The main dietary contributors for total polyphenols were coffee (70·5 %), citrus fruits (4·6 %) and tropical fruits (3·4 %). Coffee was the major source of polyphenols, providing 266·2 (se 16·5) mg/d, and contributed 92·3 % of the phenolic acids and 93·1 % of the alkylmethoxyphenols. These findings will be useful for assessing the potential role on health of polyphenols and specific polyphenol-rich foods, such as coffee, and enable a comparison with people from other countries.

  5. Dietary intake and food contributors of polyphenols in adults and elderly adults of Sao Paulo: a population-based study.

    PubMed

    Miranda, A M; Steluti, J; Fisberg, R M; Marchioni, D M

    2016-03-28

    A comprehensive estimation of polyphenol intake is needed to gain a better understanding of the association between polyphenol-rich food intake and the potential effects of this intake on chronic diseases. The aim of this study was to estimate the intake of polyphenols and the major dietary contributors in the population of Sao Paulo. Data were obtained from the Health Survey-São Paulo (ISA-Capital 2008) and were reported for 1103 adults and elderly adults. Food intake was estimated by one 24-h dietary recall (24HR). Polyphenol intake was calculated by matching food consumption data from the 24HR with the polyphenol content in foods listed in the Phenol-Explorer database. The mean total intake of polyphenols was 377·5 (se 15·3) mg/d. The main polyphenol classes were phenolic acids (284·8 (se 15·9) mg/d) and flavonoids (54·6 (se 3·5) mg/d). Intakes were higher in the elderly adults than in other adults (P<0·001) and higher in individuals with lower educational level (P=0·01) and current smokers (P=0·02). The main dietary contributors for total polyphenols were coffee (70·5 %), citrus fruits (4·6 %) and tropical fruits (3·4 %). Coffee was the major source of polyphenols, providing 266·2 (se 16·5) mg/d, and contributed 92·3 % of the phenolic acids and 93·1 % of the alkylmethoxyphenols. These findings will be useful for assessing the potential role on health of polyphenols and specific polyphenol-rich foods, such as coffee, and enable a comparison with people from other countries. PMID:26810764

  6. Facing warm temperatures during migration: cardiac mRNA responses of two adult Oncorhynchus nerka populations to warming and swimming challenges.

    PubMed

    Anttila, K; Eliason, E J; Kaukinen, K H; Miller, K M; Farrell, A P

    2014-05-01

    The main findings of the current study were that exposing adult sockeye salmon Onchorhynchus nerka to a warm temperature that they regularly encounter during their river migration induced a heat shock response at an mRNA level, and this response was exacerbated with forced swimming. Similar to the heat shock response, increased immune defence-related responses were also observed after warm temperature treatment and with a swimming challenge in two different populations (Chilko and Nechako), but with some important differences. Microarray analyses revealed that 347 genes were differentially expressed between the cold (12-13° C) and warm (18-19° C) treated fish, with stress response (GO:0006950) and response to fungus (GO:0009620) elevated with warm treatment, while expression for genes involved in oxidative phosphorylation (GO:0006119) and electron transport chain (GO:0022900) elevated for cold-treated fish. Analysis of single genes with real-time quantitative PCR revealed that temperature had the most significant effect on mRNA expression levels, with swimming and population having secondary influences. Warm temperature treatment for the Chilko population induced expression of heat shock protein (hsp) 90α, hsp90β and hsp30 as well as interferon-inducible protein. The Nechako population, which is known to have a narrower thermal tolerance window than the Chilko population, showed even more pronounced stress responses to the warm treatment and there was significant interaction between population and temperature treatment for hsp90β expression. Moreover, significant interactions were noted between temperature treatment and swimming challenge for hsp90α and hsp30, and while swimming challenge alone increased expression of these hsps, the expression levels were significantly elevated in warm-treated fish swum to exhaustion. In conclusion, it seems that adult O. nerka currently encounter conditions that induce several cellular defence mechanisms during their once

  7. [Fish population structure in the fishway of Changzhou hydro-junction].

    PubMed

    Tan, Xi-chang; Huang, He; Tao, Jiang-ping; Li, Si-jia

    2015-05-01

    The fishway of Changzhou hydro-junction, located in the main stream of Xijiang River, is the biggest fishway in China up to now. Efficiency assessment of the Changzhou fishway is important for fish resource and ecosystem protection of the Pearl River, and can provide basic data for design, construction and management of other fishways in China. A total of 40 fish species in the Changzhou fishway were sampled on 11 occasions from April to June during 2011-2014 by using blocking method. Migratory species such as marbled eel, eel, Fugu ocellatus and the four domestic fish ( black carp, grass carp, silver carp and bighead carp) appeared in the fishway. The dominant species included Pelteobagrus vachelli (29.1%), Spualiobarbus' curriculus (16.8%), Hemiculter leucisculus (14.7%), Pseudolaubuca sinensis (12.0%), Squalidus argentatus (10.8%), Anguilla japonica (7.3%) and Cirrhinus molitorella (2.7%). Species accumulation curve indicated that up to 61 species would be monitored in the fishway with increasing the sampling frequency, indicating its good passage efficiency. Fish diversity in the Changzhou fishway was significantly lower than that in the downstream in Xijiang River, and two dominant species in the downstream of the Changzhou Dam, Megalobrama hoffmanni and Mystus guttatus, were not monitored in the fishway in this study, revealing that attraction efficiency of the fishway was different for different fish species. The canonical correspondence analysis showed that dam water level was the most important factor for the fishway effectiveness, it was necessary to adjust the operation mode of the Changzhou dam to instigate more fish migration by the fishway. According to the present situation of fishery resources of the Pearl River, it was suggested to include four domestic fish, M. hoffmanni, S. curriculus and C. molitorella as target species of the Changzhou fishway, and consider more about ecological characteristics of these species. PMID:26571676

  8. Genetic effective size is three orders of magnitude smaller than adult census size in an abundant, Estuarine-dependent marine fish (Sciaenops ocellatus).

    PubMed

    Turner, Thomas F; Wares, John P; Gold, John R

    2002-11-01

    Using eight microsatellite loci and a variety of analytical methods, we estimated genetic effective size (N(e)) of an abundant and long-lived marine fish species, the red drum (Sciaenops ocellatus), in the northern Gulf of Mexico (Gulf). The ratio N(e)/N, where short-term variance N(e) was estimated via the temporal method from shifts in allele-frequency data over four cohorts and where N reflected a current estimate of adult census size in the northern Gulf, was approximately 0.001. In an idealized population, this ratio should approximate unity. The extraordinarily low value of N(e)/N appears to arise from high variance in individual reproductive success and perhaps more importantly from variance in productivity of critical spawning and nursery habitats located in spatially discrete bays and estuaries throughout the northern Gulf. An estimate of N(e) based on a coalescent approach, which measures long-term, inbreeding effective size, was four orders of magnitude lower than the estimate of current census size, suggesting that factors presently driving N(e)/N to low values among red drum in the northern Gulf may have operated similarly in the past. Models that predict N(e)/N exclusively from demographic and life-history features will seriously overestimate N(e) if variance in reproductive success and variance in productivity among spatially discrete demes is underestimated. Our results indicate that these variances, especially variance in productivity among demes, must be large for red drum. Moreover, our study indicates that vertebrate populations with enormous adult census numbers may still be at risk relative to decline and extinction from genetic factors.

  9. Genetic effective size is three orders of magnitude smaller than adult census size in an abundant, Estuarine-dependent marine fish (Sciaenops ocellatus).

    PubMed Central

    Turner, Thomas F; Wares, John P; Gold, John R

    2002-01-01

    Using eight microsatellite loci and a variety of analytical methods, we estimated genetic effective size (N(e)) of an abundant and long-lived marine fish species, the red drum (Sciaenops ocellatus), in the northern Gulf of Mexico (Gulf). The ratio N(e)/N, where short-term variance N(e) was estimated via the temporal method from shifts in allele-frequency data over four cohorts and where N reflected a current estimate of adult census size in the northern Gulf, was approximately 0.001. In an idealized population, this ratio should approximate unity. The extraordinarily low value of N(e)/N appears to arise from high variance in individual reproductive success and perhaps more importantly from variance in productivity of critical spawning and nursery habitats located in spatially discrete bays and estuaries throughout the northern Gulf. An estimate of N(e) based on a coalescent approach, which measures long-term, inbreeding effective size, was four orders of magnitude lower than the estimate of current census size, suggesting that factors presently driving N(e)/N to low values among red drum in the northern Gulf may have operated similarly in the past. Models that predict N(e)/N exclusively from demographic and life-history features will seriously overestimate N(e) if variance in reproductive success and variance in productivity among spatially discrete demes is underestimated. Our results indicate that these variances, especially variance in productivity among demes, must be large for red drum. Moreover, our study indicates that vertebrate populations with enormous adult census numbers may still be at risk relative to decline and extinction from genetic factors. PMID:12454077

  10. Fish community changes in the St. Louis River estuary, Lake Superior, 1989-1996: Is it ruffe or population dynamics?

    USGS Publications Warehouse

    Bronte, Charles R.; Evrard, Lori M.; Brown, William P.; Mayo, Kathleen R.; Edwards, Andrew J.

    1998-01-01

    Ruffe (Gymnocephalus cernuus) have been implicated in density declines of native species through egg predation and competition for food in some European waters where they were introduced. Density estimates for ruffe and principal native fishes in the St. Louis River estuary (western Lake Superior) were developed for 1989 to 1996 to measure changes in the fish community in response to an unintentional introduction of ruffe. During the study, ruffe density increased and the densities of several native species decreased. The reductions of native stocks to the natural population dynamics of the same species from Chequamegon Bay, Lake Superior (an area with very few ruffe) were developed, where there was a 24-year record of density. Using these data, short- and long-term variations in catch and correlations among species within years were compared, and species-specific distributions were developed of observed trends in abundance of native fishes in Chequamegon Bay indexed by the slopes of densities across years. From these distributions and our observed trend-line slopes from the St. Louis River, probabilities of measuring negative change at the magnitude observed in the St. Louis River were estimated. Compared with trends in Chequamegon Bay, there was a high probability of obtaining the negative slopes measured for most species, which suggests natural population dynamics could explain, the declines rather than interactions with ruffe. Variable recruitment, which was not related to ruffe density, and associated density-dependent changes in mortality likely were responsible for density declines of native species.

  11. Links between Childhood and Adult Social Circumstances and Obesity and Hypertension in the Mexican Population

    PubMed Central

    Beltrán-Sánchez, Hiram; Crimmins, Eileen M.; Teruel, Graciela M.; Thomas, Duncan

    2011-01-01

    Objectives This study examines links between early life circumstances and adult socioeconomic status and obesity and hypertension in the adult Mexican population. Methods We use data from the Mexican Family Life Survey (MxFLS) collected in 2002 for people aged 20 or older (N=14, 280). Results We found that men with low education and women with more education have significantly lower obesity. Women with higher education also have significantly less hypertension. Obesity triples the likelihood of hypertension among both men and women. Better childhood experiences are associated with less hypertension among women, but more hypertension among men in rural areas. Discussion Recent changes in income, nutrition, and infection in Mexico may be responsible for the observed high prevalence of overweight and obesity and the extremely high odds of hypertension among obese young adults. PMID:21948773

  12. Intentional genetic introgression influences survival of adults and subadults in a small, inbred felid population.

    PubMed

    Benson, John F; Hostetler, Jeffrey A; Onorato, David P; Johnson, Warren E; Roelke, Melody E; O'Brien, Stephen J; Jansen, Deborah; Oli, Madan K

    2011-09-01

    1. Inbreeding and low genetic diversity can cause reductions in individual fitness and increase extinction risk in animal populations. Intentional introgression, achieved by releasing genetically diverse individuals into inbred populations, has been used as a conservation tool to improve demographic performance in endangered populations. 2. By the 1980s, Florida panthers (Puma concolor coryi) had been reduced to a small, inbred population that appeared to be on the brink of extinction. In 1995, female pumas from Texas (P. c. stanleyana) were released in occupied panther range as part of an intentional introgression programme to restore genetic variability and improve demographic performance of panthers. 3. We used 25 years (1981-2006) of continuous radiotelemetry and genetic data to estimate and model subadult and adult panther survival and cause-specific mortality to provide rigorous sex and age class-specific survival estimates and evaluate the effect of the introgression programme on these parameters. 4. Genetic ancestry influenced annual survival of subadults and adults after introgression, as F(1) generation admixed panthers ( = 0·98) survived better than pre-introgression type panthers ( = 0·77) and other admixed individuals ( = 0·82). Furthermore, heterozygosity was higher for admixed panthers relative to pre-introgression type panthers and positively influenced survival. 5. Our results are consistent with hybrid vigour; however, extrinsic factors such as low density of males in some areas of panther range may also have contributed to higher survival of F(1) panthers. Regardless, improved survival of F(1) subadults and adults likely contributed to the numerical increase in panthers following introgression, and our results indicate that intentional admixture, achieved here by releasing individuals from another population, appears to have been successful in improving demographic performance in this highly endangered population. PMID:21338353

  13. Intentional genetic introgression influences survival of adults and subadults in a small, inbred felid population.

    PubMed

    Benson, John F; Hostetler, Jeffrey A; Onorato, David P; Johnson, Warren E; Roelke, Melody E; O'Brien, Stephen J; Jansen, Deborah; Oli, Madan K

    2011-09-01

    1. Inbreeding and low genetic diversity can cause reductions in individual fitness and increase extinction risk in animal populations. Intentional introgression, achieved by releasing genetically diverse individuals into inbred populations, has been used as a conservation tool to improve demographic performance in endangered populations. 2. By the 1980s, Florida panthers (Puma concolor coryi) had been reduced to a small, inbred population that appeared to be on the brink of extinction. In 1995, female pumas from Texas (P. c. stanleyana) were released in occupied panther range as part of an intentional introgression programme to restore genetic variability and improve demographic performance of panthers. 3. We used 25 years (1981-2006) of continuous radiotelemetry and genetic data to estimate and model subadult and adult panther survival and cause-specific mortality to provide rigorous sex and age class-specific survival estimates and evaluate the effect of the introgression programme on these parameters. 4. Genetic ancestry influenced annual survival of subadults and adults after introgression, as F(1) generation admixed panthers ( = 0·98) survived better than pre-introgression type panthers ( = 0·77) and other admixed individuals ( = 0·82). Furthermore, heterozygosity was higher for admixed panthers relative to pre-introgression type panthers and positively influenced survival. 5. Our results are consistent with hybrid vigour; however, extrinsic factors such as low density of males in some areas of panther range may also have contributed to higher survival of F(1) panthers. Regardless, improved survival of F(1) subadults and adults likely contributed to the numerical increase in panthers following introgression, and our results indicate that intentional admixture, achieved here by releasing individuals from another population, appears to have been successful in improving demographic performance in this highly endangered population.

  14. Midwater trawl catches of adolescent and adult anguilliform fishes during the Sargasso Sea Eel Expedition 1979

    NASA Astrophysics Data System (ADS)

    Post, A.; Tesch, F.-W.

    1982-09-01

    During the research program on the biology and migration of Anguilla spp. carried out with F.R.V. “Anton Dohrn” in 1979, approximately 1300 adolescent and adult anguilliform individuals were caught covering 8 families, 10 genera and 12 species. Observations on each of these species, including horizontal and vertical distributional patterns, are dealt with herein. The appearance of various species in hauls and the absence of adult Anguilla spp. in the catches obtained are discussed.

  15. Episodic acidification of small streams in the northeastern united states: Effects on fish populations

    USGS Publications Warehouse

    Baker, J.P.; Van Sickle, J.; Gagen, C.J.; DeWalle, David R.; Sharpe, W.E.; Carline, R.F.; Baldigo, Barry P.; Murdoch, Peter S.; Bath, D.W.; Kretser, W.A.; Simonin, H.A.; Wigington, P.J.

    1996-01-01

    As part of the Episodic Response Project (ERP), we studied the effects of episodic acidification on fish in 13 small streams in the northeastern United States: four streams in the Adirondack region of New York, four streams in the Catskills, New York, and five streams in the northern Appalachian Plateau, Pennsylvania. In situ bioassays with brook trout (Salvelinus fontinalis) and a forage fish species (blacknose dace (Rhinichthys atratulus], mottled sculpin (Cottus bairdi), or slimy sculpin (Cottus cognatus), depending on the region) measured direct toxicity. Movements of individual brook trout, in relation to stream chemistry, were monitored using radiotelemetry. Electrofishing surveys assessed fish community status and the density and biomass of brook trout in each stream. During low flow, all streams except one had chemical conditions considered suitable for the survival and reproduction of most fish species (median pH 6.0-7.2 during low flow; inorganic Al 100-200 ??g/L. We conclude that episodic acidification can have long-term effects on fish communities in small streams.

  16. Two-generation analysis of pollen flow across a landscape. III. Impact of adult population structure.

    PubMed

    Austerlitz, F; Smouse, P E

    2001-12-01

    The rate and distance of instantaneous pollen flow in a population are parameters of considerable current interest for plant population geneticists and conservation biologists. We have recently developed an estimator (phi ft) of differentiation between the inferred pollen clouds that fertilize several females, sampled within a single population. We have shown that there is a simple relation between phi ft and the average pollen dispersal distance (delta) for the case of a population with no geographic structure. Though forest trees usually show considerable pollen flow, assuming an absence of spatially distributed genetic structure is not always wise. Here, we develop analytical theory for the relation between phi ft and delta, for the case where the probability of Identity by Descent (IBD) for two individuals decreases with the physical distance between them. This analytical theory allows us to provide an effective method for estimating pollen dispersal distance in a population with adult genetic structure. Using real examples, we show that estimation errors can be large if genetic structure is not taken into account, so it is wise to evaluate adult genetic structure simultaneously with estimation of phi ft for the pollen clouds. We show that the results are only moderately affected by changes in the decay function, a result of some importance since no completely established theory is available for this function.

  17. Possible secondary population-level effects of selective harvest of adult male muskoxen.

    PubMed

    Schmidt, Joshua H; Gorn, Tony S

    2013-01-01

    Selective harvest regimes are often focused on males resulting in skewed sex-ratios, and for many ungulate species this strategy is sustainable. However, muskoxen (Ovibos moschatus) are very social and mature bulls (≥4 years old), particularly prime-age bulls (6-10 years old), play important roles in predator defense and recruitment. A year-round social structure incorporating large males into mixed-sex groups could make this species more susceptible to the effects of selective harvest if population composition and sex-ratios influence overall survival and reproductive success. Using detailed data collected on the muskox population occupying the Seward Peninsula, Alaska during 2002-2012, we formulated the hypothesis that the selective harvest of mature bulls may be related to documented changes in population composition and growth rates in this species. In addition, we reviewed existing published information from two other populations in Alaska, the Cape Thompson and Northeastern populations, to compare population growth rates among the three areas under differential harvest rates relative to our hypothesis. We found that on the Seward Peninsula, mature bull:adult cow ratios declined 4-12%/year and short-yearling:adult cow ratios (i.e., recruitment) declined 8-9%/year in the most heavily harvested areas. Growth rates in all 3 populations decreased disproportionately after increases in the number of bulls harvested, and calf:cow ratios declined in the Northeastern population as harvest increased. While lack of appropriate data prevented us from excluding other potential causes such as density dependent effects and changes in predator densities, our results did align with our hypothesis, suggesting that in the interest of conservation, harvest of mature males should be restricted until causal factors can be more definitively identified. If confirmed by additional research, our findings would have important implications for h