75 FR 69601 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Western Aleutian...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-15

.... 0910131363-0087-02] RIN 0648-XA036 Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch.... ACTION: Temporary rule; closure. SUMMARY: NMFS is prohibiting directed fishing for Pacific ocean perch in... allocation of Pacific ocean perch in this area allocated to vessels participating in the BSAI trawl limited...

77 FR 42439 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the West Yakutat...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-19

.... 111207737-2141-02] RIN 0648-XC113 Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch...: NMFS is prohibiting directed fishing for Pacific ocean perch in the West Yakutat District of the Gulf...) of Pacific ocean perch in the West Yakutat District of the GOA. DATES: Effective 1200 hrs, Alaska...

75 FR 53608 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the West Yakutat...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-01

.... 0910131362-0087-02] RIN 0648-XY66 Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in...: NMFS is prohibiting directed fishing for Pacific ocean perch in the West Yakutat District of the Gulf...) of Pacific ocean perch in the West Yakutat District of the GOA. DATES: Effective 1200 hrs, Alaska...

78 FR 44465 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the West Yakutat...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-24

.... 120918468-3111-02] RIN 0648-XC771 Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch...: NMFS is prohibiting directed fishing for Pacific ocean perch in the West Yakutat District of the Gulf...) of Pacific ocean perch in the West Yakutat District of the GOA. DATES: Effective 1200 hours, Alaska...

Fate of a perched crystal layer in a magma ocean

NASA Technical Reports Server (NTRS)

Morse, S. A.

1992-01-01

The pressure gradients and liquid compressibilities of deep magma oceans should sustain the internal flotation of native crystals owing to a density crossover between crystal and liquid. Olivine at upper mantle depths near 250 km is considered. The behavior of a perched crystal layer is part of the general question concerning the fate of any transient crystal carried away from a cooling surface, whether this be a planetary surface or the roof of an intrusive magma body. For magma bodies thicker than a few hundred meters at modest crustal depths, the major cooling surface is the roof even when most solidification occurs at the floor. Importation of cool surroundings must also be invoked for the generation of a perched crystal layer in a magma ocean, but in this case the perched layer is deeply embedded in the hot part of the magma body, and far away from any cooling surface. Other aspects of this study are presented.

78 FR 42718 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Bering Sea and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-17

.... 121018563-3148-02] RIN 0648-XC757 Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch...; closure. SUMMARY: NMFS is prohibiting directed fishing for Pacific ocean perch in the Western Aleutian... allowable catch (TAC) of Pacific ocean perch in this area allocated to vessels participating in the BSAI...

77 FR 41332 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Western...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-13

.... 111207737-2141-02] RIN 0648-XC109 Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch...: NMFS is prohibiting retention of Pacific ocean perch in the Western Regulatory Area of the Gulf of Alaska (GOA). This action is necessary because the 2012 total allowable catch (TAC) of Pacific ocean...

75 FR 42338 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Western...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-21

.... 0910131362-0087-02] RIN 0648-XX72 Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in...: NMFS is prohibiting retention of Pacific ocean perch in the Western Regulatory Area of the Gulf of Alaska (GOA). This action is necessary because the 2010 total allowable catch (TAC) of Pacific ocean...

75 FR 53873 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Vessels...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-02

.... 0910131362-0087-02] RIN 0648-XY70 Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Vessels Participating in the Rockfish Entry Level Fishery in the Central Regulatory Area of the... for Pacific ocean perch for vessels participating in the rockfish entry level fishery in the Central...

75 FR 38936 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-07

.... 0910131362-0087-02] RIN 0648-XX35 Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels Participating in the Rockfish Entry Level Trawl Fishery in the Central Regulatory... directed fishing for Pacific ocean perch by trawl catcher vessels participating in the rockfish entry level...

76 FR 39790 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-07

.... 101126522-0640-02] RIN 0648-XA543 Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels Participating in the Rockfish Entry Level Trawl Fishery in the Central Regulatory... directed fishing for Pacific ocean perch by trawl catcher vessels participating in the rockfish entry level...

76 FR 70420 - Fisheries of the Pacific Region

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-14

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XA801 Fisheries of the Pacific Region AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric... that Pacific ocean perch, (Sebastes alutus), which is managed by the Pacific Fishery Management Council...

78 FR 64891 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Bering Sea and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-30

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 679 [Docket No. 121018563-3148-02] RIN 0648-XC944 Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch... (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce. ACTION: Temporary rule...

78 FR 64892 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Bering Sea and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-30

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 679 [Docket No. 121018563-3148-02] RIN 0648-XC943 Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch... (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce. ACTION: Temporary rule...

75 FR 41999 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-20

.... 0910131362-0087-02] RIN 0648-XX65 Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels Participating in the Rockfish Entry Level Trawl Fishery in the Central Regulatory... entry level fishery in the Central Regulatory Area of the Gulf of Alaska (GOA). This action is necessary...

76 FR 54716 - Fisheries of the Exclusive Economic Zone off Alaska; Northern Rockfish, Pacific Ocean Perch, and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-02

.... 101126522-0640-02] RIN 0648-XA678 Fisheries of the Exclusive Economic Zone off Alaska; Northern Rockfish, Pacific Ocean Perch, and Pelagic Shelf Rockfish for Vessels Participating in the Rockfish Entry Level... rockfish entry level fishery in the Central Regulatory Area of the Gulf of Alaska (GOA). This action is...

76 FR 46207 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-02

.... 101126522-0640-02] RIN 0648-XA612 Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels Participating in the Rockfish Entry Level Trawl Fishery in the Central Regulatory... rockfish entry level fishery in the Central Regulatory Area of the Gulf of Alaska (GOA) for 48 hours. This...

76 FR 40838 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-12

.... 101126522-0640-02] RIN 0648-XA558 Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels Participating in the Rockfish Entry Level Trawl Fishery in the Central Regulatory... rockfish entry level fishery in the Central Regulatory Area of the Gulf of Alaska (GOA) for 48 hours. This...

76 FR 70665 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Bering Sea...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-15

... in the Bering Sea Subarea of the Bering Sea and Aleutian Islands Management Area AGENCY: National...-specified reserve to the initial total allowable catch of Pacific ocean perch in the Bering Sea subarea of the Bering Sea and Aleutian Islands management area. This action is necessary to allow fishing...

75 FR 69361 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Bering Sea...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-12

... the Bering Sea Subarea of the Bering Sea and Aleutian Islands Management Area AGENCY: National Marine...-specified reserve to the initial total allowable catch of Pacific ocean perch in the Bering Sea subarea of the Bering Sea and Aleutian Islands management area. This action is necessary to allow fishing...

76 FR 68658 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Bering Sea...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-07

... in the Bering Sea Subarea of the Bering Sea and Aleutian Islands Management Area AGENCY: National... Pacific ocean perch in the Bering Sea subarea of the Bering Sea and Aleutian Islands management area. This... Bering Sea subarea of the Bering Sea and Aleutian Islands management area. DATES: Effective 1200 hrs...

78 FR 73110 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Bering Sea...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-05

... in the Bering Sea Subarea of the Bering Sea and Aleutian Islands Management Area AGENCY: National... in the Bering Sea subarea of the Bering Sea and Aleutian Islands management area. This action is necessary to fully use the 2013 total allowable catch of Pacific ocean perch specified for the Bering Sea...

75 FR 68726 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Bering Sea...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-09

... in the Bering Sea Subarea of the Bering Sea and Aleutian Islands Management Area AGENCY: National... in the Bering Sea subarea of the Bering Sea and Aleutian Islands management area. This action is necessary to fully use the 2010 total allowable catch of Pacific ocean perch specified for the Bering Sea...

77 FR 65838 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Bering Sea...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-31

... in the Bering Sea Subarea of the Bering Sea and Aleutian Islands Management Area AGENCY: National... in the Bering Sea subarea of the Bering Sea and Aleutian Islands management area. This action is necessary to fully use the 2012 total allowable catch of Pacific ocean perch specified for the Bering Sea...

Dynamics of a parasite assemblage of the Vermilion Rockfish Sebastes miniatus from northwestern Baja California, México

NASA Astrophysics Data System (ADS)

Rodríguez-Santiago, M. A.; Rosales-Casián, J. A.; Grano-Maldonado, M. I.

2014-06-01

A parasite assemblage of Sebastes miniatus from northwestern Baja California, México, was composed of a total of 12 species: five ectoparasites (two monogeneans and three parasitic copepods) and seven endoparasites (two digeneans, one cestode, three nematodes, and one acanthocephala). Five of these parasites constituted new genera records to the genus Sebastes, and nine were new geographic records. The most abundant species were the endoparasites Parabothriocephalus sagitticeps, Hysterothylacium sp., and Anisakis sp., and the specific richness ranged from 1 to 8 parasite species per host. The most important parasite species in terms of prevalence were Microcotyle sebastis (93 %) and Anisakis sp. (92 %). The mean abundance of parasites found in S. miniatus showed significant variations over the year, with maximum values (31.7 individuals/host) in August, and minimum (0.39 individuals/host) in February. P. sagitticeps showed the highest mean intensity of infection (190.4 parasites/host), followed by Anisakis sp. (127.2 parasites/host) and Hysterothylacium sp. (46.6 parasites/host). The presence of larval stages of the nematodes Anisakis, Pseudoterranova, and Hysterothylacium is particularly important due to their high abundance and prevalence and because they may represent a human health risk (anisakiasis). Rockfishes (family Scorpaenidae) of the genus Sebastes constitute one of the most important groundfish resources in the American and Mexican northern Pacific Ocean, both for recreational and for the commercial fisheries of California and Baja California. These rockfish species makes up a substantial part of the Mexican cuisine.

Age validation of quillback rockfish (Sebastes maliger) using bomb radiocarbon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kerr, L A; Andrews, A H; Munk, K

2005-01-05

Rockfishes (Sebastes spp.) support one of the most economically important fisheries of the Pacific Northwest and it is essential for sustainable management that age estimation procedures be validated for these species. Atmospheric testing of thermonuclear devices during the 1950s and 1960s created a global radiocarbon ({sup 14}C) signal in the ocean environment that scientists have identified as a useful tracer and chronological marker in natural systems. In this study, we first demonstrated that fewer samples are necessary for age validation using the bomb-generated {sup 14}C signal by emphasizing the utility of the time-specific marker created by the initial rise ofmore » bomb-{sup 14}C. Second, the bomb-generated {sup 14}C signal retained in fish otoliths was used to validate the age and age estimation methodology of the quillback rockfish (Sebastes maliger) in the waters of southeast Alaska. Radiocarbon values from the first year's growth of quillback rockfish otoliths were plotted against estimated birth year producing a {sup 14}C time series spanning 1950 to 1985. The initial rise of bomb-{sup 14}C from pre-bomb levels ({approx} -90 {per_thousand}) occurred in 1959 {+-} 1 year and {sup 14}C levels rose relatively rapidly to peak {Delta}{sup 14}C values in 1967 (+105.4 {per_thousand}), with a subsequent declining trend through the end of the record in 1985 (+15.4 {per_thousand}). The agreement between the year of initial rise of {sup 14}C levels from the quillback rockfish record and the chronometer determined for the waters of southeast Alaska from yelloweye rockfish (S. ruberrimus) otoliths validated the ageing methodology for the quillback rockfish. The concordance of the entire quillback rockfish {sup 14}C record with the yelloweye rockfish time series demonstrated the effectiveness of this age validation technique, confirmed the longevity of the quillback rockfish up to a minimum of 43 years, and strongly supports higher age estimates of up to 90 years.« less

Sea Perch Project

NASA Image and Video Library

2010-12-11

David Lalejini, an employee of the Naval Research Laboratory at NASA's John C. Stennis Space Center, helps a pair of teachers deploy a remotely-operated underwater Sea Perch robot during workshop activities Dec. 11. The Stennis Education Office teamed with Naval Research Laboratory counterparts to conduct a two-day workshop Dec. 10-11 for Louisiana and Mississippi teachers. During the no-cost workshop, teachers learned to build and operate Sea Perch robots. The teachers now can take the Sea Perch Program back to students.

Sea Perch Project

NASA Technical Reports Server (NTRS)

2010-01-01

David Lalejini, an employee of the Naval Research Laboratory at NASA's John C. Stennis Space Center, helps a pair of teachers deploy a remotely-operated underwater Sea Perch robot during workshop activities Dec. 11. The Stennis Education Office teamed with Naval Research Laboratory counterparts to conduct a two-day workshop Dec. 10-11 for Louisiana and Mississippi teachers. During the no-cost workshop, teachers learned to build and operate Sea Perch robots. The teachers now can take the Sea Perch Program back to students.

A Case Report of Acute Vitamin A Intoxication due to Ocean Perch Liver Ingestion.

PubMed

Homma, Yosuke; Otani, Norio; Ishimatsu, Shinichi

2015-07-01

Chronic vitamin A intoxication is well known; however, there are few reports of acute vitamin A intoxication due to the ingestion of food rich in vitamin A, particularly in adults. We report a case of a 27-year-old man presenting with chief complaints of flushing, headache, nausea, and joint pain. He had consumed 800 g of grilled ocean perch liver the day before and had experienced numbness shortly after. Although physical examination revealed only facial flushing, we suspected acute vitamin A intoxication due to his diet history. On day 2 after ingestion, his serum retinol levels were elevated at 1577 ng/mL, which confirmed vitamin A intoxication. He returned for follow-up on day 4 after ingestion, by which time his presenting symptoms had improved, but he had developed desquamation of his facial skin. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians should consider acute vitamin A intoxication in the differential diagnosis of patients with headache, flushing, desquamation, nausea, and vomiting of unknown etiology. Complete diet histories and checking vitamin A levels are essential for diagnosis. This report highlights the diagnostic difficulties associated with vitamin A intoxication and the importance of an accurate diet history. Copyright © 2015 Elsevier Inc. All rights reserved.

Effect of perches on liver health of hens.

PubMed

Jiang, S; Hester, P Y; Hu, J Y; Yan, F F; Dennis, R L; Cheng, H W

2014-07-01

Fatty liver is a common energy metabolic disorder in caged laying hens. Considering that the egg industry is shifting from conventional cages to alternative housing systems such as enriched cages, the objective of this study was to determine the effects of perches on fat deposition and liver health in laying hens. Three hundred twenty-four 17-wk-old White Leghorn hens were housed in 1 of 4 treatments with 9 hens per cage. Treatment 1 hens never had access to perches during their life cycle. Treatment 2 hens had access to perches during the pullet phase only. Treatment 3 hens had access to perches during the laying phase only. Treatment 4 hens always had access to perches. Liver weight, abdominal fat pad weight, BW, liver fat, and circulating alanine transaminase, aspartate transaminase, and adiponectin were determined. Provision of perches during either the rearing or laying phase did not affect liver health in 71-wk-old hens. However, perch access compared with no perch access during the egg laying phase reduced relative fat pad weight. These results suggest that providing perches as a means of stimulating activity reduced abdominal fat deposition in caged hens during the laying period. However, perch access in caged hens was ineffective in reducing fat deposition in the liver and altering enzyme activities related to improved liver function. © 2014 Poultry Science Association Inc.

Experimental analysis of perching in the European starling (Sturnus vulgaris: Passeriformes; Passeres), and the automatic perching mechanism of birds.

PubMed

Galton, Peter M; Shepherd, Jeffrey D

2012-04-01

The avian automatic perching mechanism (APM) involves the automatic digital flexor mechanism (ADFM) and the digital tendon-locking mechanism (DTLM). When birds squat on a perch to sleep, the increased tendon travel distance due to flexion of the knee and ankle supposedly causes the toes to grip the perch (ADFM) and engage the DTLM so perching while sleeping involves no muscular effort. However, the knees and ankles of sleeping European starlings (Sturnus vulgaris) are only slightly flexed and, except for occasional balancing adjustments, the distal two-thirds of the toes are not flexed to grip a 6-mm-diameter perch. The cranial ankle angle (CAA) is ∼120° and the foot forms an inverted "U" that, with the mostly unflexed toes, provides a saddle-like structure so the bird balances its weight over the central pad of the foot (during day weight further back and digits actively grasp perch). In the region of the pad, the tendon sheath of many birds is unribbed, or only very slightly so, and it is always separated from the tendon of the M. flexor digitorum longus by tendons of the other toe flexor muscles. Passive leg flexion produces no toe flexion in anesthetized Starlings and only after 15-20 min, at the onset of rigor mortis, in freshly sacrificed Starlings. Anesthetized Starlings could not remain perched upon becoming unconscious (ADFM, DTLM intact). Birds whose digital flexor tendons were severed or the locking mechanism eliminated surgically (no ADFM or DTLM), so without ability to flex their toes, slept on the perch in a manner similar to unoperated Starlings (except CAA ∼90°-110°). Consequently, there is no APM or ADFM and the DTLM, although involved in lots of other activities, only acts in perching with active contraction of the digital flexor muscles. © 2012 WILEY PERIODICALS, INC.

Food of alewives, yellow perch, spottail shiners, trout-perch, and slimy and fourhorn sculpins in southeastern Lake Michigan

USGS Publications Warehouse

Wells, LaRue

1980-01-01

Stomachs of 1,064 alewives (Alosa pseudoharengus), 1,103 yellow perch (Perca flavescens), 246 spottail shiners (Notropis hudsonius), 288 trout-perch (Percopsis omiscomaycus), 454 slimy sculpins (Cottus cognatus), and 562 fourhorn sculpins (Myoxocephalus quadricornis) from Lake Michigan were examined for food contents. Fish were sampled primarily from March to November and nearly all were caught at the bottom in the southeastern part of the lake near Saugatuck, Michigan. Depths of capture (m) were: alewives, 5 to 110; yellow perch, 5 to 26; spottail shiners, 5 to 31; trout-perch, 9 to 46; slimy sculpins, 31 to 91; and fourhorn sculpins, 73 to 110. Alewives, particularly those less than 140 mm long, fed chiefly on zooplankton; Pontoporeia usually constituted most of the rest of the food, although Mysis and immature midges were occasionally eaten in considerable quantity. Yellow perch ate primarily Pontoporeia, fish eggs, Mysis, and crayfish; Pontoporeia was consumed most heavily by perch less than 250 mm long and those in relatively deep water, fish (mainly slimy sculpins) by those 200 mm long or longer, Mysis by those in deep water, and crayfish by those on rocky bottom. Spottail shiners fed most commonly on immature midges, Pontoporeia, zooplankton, fingernail clams, and (in July only) fish eggs; immature midges were eaten mainly by shiners in shallow water; and Pontoporeia by those in deeper areas. The diet of trout-perch was strongly dominated by Pontoporeia and immature midges. Slimy sculpins ate Pontoporeia almost exclusively. Fourhorn sculpins fed almost entirely on Mysis and Pontoporeia; Pontoporeia was particularly important in the diet of the larger fish.

Introgression among three rockfish species (Sebastes spp.) in the Salish Sea, northeast Pacific Ocean

PubMed Central

Park, Linda K.; Hauser, Lorenz

2018-01-01

Interspecific hybridization is often seen as a major conservation issue, potentially threatening endangered species and decreasing biodiversity. In natural populations, the conservation implications of hybridization depends on both on anthropogenic factors and the evolutionary processes maintaining the hybrid zone. However, the timeline and patterns of hybridization in the hybrid zone are often not known. Therefore, species conservation becomes a concern when recent anthropogenic changes influence hybridization and not if hybridization is part of a long-term process. Here, we use sequence data from one mitochondrial gene, three nuclear introns and one nuclear exon to estimate the direction, geographic extent, frequency and possible timeline of hybridization between three rockfish species (Sebastes auriculatus, S. caurinus, S. maliger) in the Salish Sea, Washington, USA. We show that (i) introgression occurred much more frequently in the Salish Sea than on the outer coast, (ii) introgression was highly asymmetrical from S. maliger into the other two species, (iii) almost 40% of individuals in the Salish Sea were hybrids, with frequency of hybrids increasing with isolation from the coast, and (iv) all hybrids were later generation backcrosses rather than F1 hybrids. Our results suggest long-standing low-level hybridization rather than recent onset of interbreeding because of human induced environmental change, possibly facilitated by specific environmental conditions in the sub-basins of the Salish Sea, and by differences in population sizes during recolonization of the area after the last glaciation. This rockfish hybrid system, with asymmetrical introgression and the maintenance of parental species, may prove useful to study both mechanisms that maintain species boundaries and that facilitate speciation in the presence of rapid environmental change. PMID:29566070

Development of a bio-inspired UAV perching system

NASA Astrophysics Data System (ADS)

Xie, Pu

Although technologies of unmanned aerial vehicles (UAVs) including micro air vehicles (MAVs) have been greatly advanced in the recent years, it is still very difficult for a UAV to perform some very challenging tasks such as perching to any desired spot reliably and agilely like a bird. Unlike the UAVs, the biological control mechanism of birds has been optimized through millions of year evolution and hence, they can perform many extremely maneuverability tasks, such as perching or grasping accurately and robustly. Therefore, we have good reason to learn from the nature in order to significantly improve the capabilities of UAVs. The development of a UAV perching system is becoming feasible, especially after a lot of research contributions in ornithology which involve the analysis of the bird's functionalities. Meanwhile, as technology advances in many engineering fields, such as airframes, propulsion, sensors, batteries, micro-electromechanical-system (MEMS), and UAV technology is also advancing rapidly. All of these research efforts in ornithology and the fast growing development technologies in UAV applications are motivating further interests and development in the area of UAV perching and grasping research. During the last decade, the research contributions about UAV perching and grasping were mainly based on fixed-wing, flapping-wing, and rotorcraft UAVs. However, most of the current researches in UAV systems with perching and grasping capability are focusing on either active (powered) grasping and perching or passive (unpowered) perching. Although birds do have both active and passive perching capabilities depending on their needs, there is no UAV perching system with both capabilities. In this project, we focused on filling this gap. Inspired by the anatomy analysis of bird legs and feet, a novel perching system has been developed to implement the bionics action for both active grasping and passive perching. In addition, for developing a robust and

The effect of predation on stunted and nonstunted white perch

USGS Publications Warehouse

Gosch, N.J.C.; Pierce, L.L.; Pope, K.L.

2010-01-01

Predation is widely regarded as a means to prevent or minimise the establishment of a stunted (high density of slow growing individuals) population. We investigated the effect of predation on two different white perch Morone americana populations (stunted and nonstunted) by examining the stomach contents of piscivorous fishes. White perch and gizzard shad dominated piscivore diets in Branched Oak Lake, whereas white perch dominated piscivore diets in Pawnee Lake. White perch consumed in the stunted population (Branched Oak Lake) were larger and older than white perch consumed in the nonstunted population (Pawnee Lake). Many of the consumed white perch in the stunted population were sexually mature and had the opportunity to spawn at least once. In contrast, all of the consumed white perch in the nonstunted population were sexually immature. Predation may have reinforced the stunting of white perch in Branched Oak Lake through removal of the largest, oldest individuals. ?? 2010 John Wiley & Sons A/S.

Perch use by laying hens in a commercial aviary1

PubMed Central

Campbell, D. L. M.; Makagon, M. M.; Swanson, J. C.; Siegford, J. M.

2016-01-01

Non-cage housing systems, such as the aviary, are being implemented by the laying hen industry, including in North America, in an attempt to improve the welfare of hens. Perches are a resource that is consistently included in aviaries. Hens are strongly motivated to perch, and perching can improve leg bone strength. However, hens may prefer elevated perches, particularly at night, and thus simply providing perches is not enough to improve welfare; they must be provided in a way that allows all hens to access them. Observations of laying hens using perches and ledges (flat, solid metal shelves to assist hens’ movement between tiers) in a commercial aviary revealed variation in where hens roosted within the tiered aviary enclosure across the flock cycle (peak, mid and end of lay; P < 0.001 for all age points). Hens most often preferred roosting in the highest enclosure levels, leading to crowding on upper perches and ledges while perch space remained available on lower levels. Restricted access to preferable perches may cause frustration in hens, leading to welfare issues. Hens roosted more on perches at peak lay than mid and end lay (P < 0.001) but roosted less on ledges at peak lay than mid and end lay (P < 0.001). Additionally, more hens roosted on both perches and ledges in the ‘dark’ observation period compared with the number of hens roosting during the ‘light’ observation period (P < 0.001). Further research should look at all structural elements within the system that are used by hens for roosting, such as edges of tiers and upper wire floors, to evaluate how changes in perching preferences across the lay cycle may correlate with system design and bird-based parameters. PMID:26994206

Development and evaluation of a SUAS perching system

NASA Astrophysics Data System (ADS)

Reynolds, Ryan

Perching has been proposed as a possible landing technique for Small Unmanned Aircraft Systems (SUAS). The current research study develops an onboard open loop perching system for a fixed-wing SUAS and examines the impact of initial flight speed and sensor placement on the perching dynamics. A catapult launcher and modified COTS aircraft were used for the experiments, while an ultrasonic sensor on the aircraft was used to detect the perching target. Thirty tests were conducted varying the initial launch speed and ultrasonic sensor placement to see if they affected the time the aircraft reaches its maximum pitch angle, since the maximum pitch angle is the optimum perching point for the aircraft. High-speed video was analyzed to obtain flight data, along with data from an onboard inertial measuring unit. The data were analyzed using a model 1, two-way ANOVA to determine if launch speed and sensor placement affect the optimum perching point where the aircraft reaches its maximum pitch angle during the maneuver. The results show the launch speed does affect the time at which the maximum pitch angle occurs, but sensor placement does not. This means a closed loop system will need to adjust its perching distance based on its initial velocity. The sensor placement not having any noticeable effect means the ultrasonic sensor can be placed on the nose or the wing of the aircraft as needed for the design. There was also no noticeable interaction between the two variables. Aerodynamic parameters such as lift, drag, and moment coefficients were derived from the dynamic equations of motion for use in numerical simulations and dynamic perching models.

Hydrogeology of Ljubljana polje perched aquifers

NASA Astrophysics Data System (ADS)

Šram, D.; Brenčič, M.

2012-04-01

Ljubljana polje aquifer lies in central part of Slovenia and is one of the biggest and most important aquifers in Slovenia. Aquifer was formed in quaternary basin which was filled with sediments from local rivers. River Sava is the biggest and the most important among them. Thickness of the aquifer varies from 20 m to 100 m. In general it is an unconfined aquifer, but locally, between gravel and sand sediments which have good hydraulic conductivity, layers with low hydraulic conductivity, such as silt and clay, appear. Those layers or lenses can form perched aquifers. Perched aquifers are important for prevention of pollution of the main aquifer and also for the water recharge in the time periods with high precipitation. The perched aquifers were located by boreholes, while their spatial distribution has not been studied yet. Within the project INCOME all the existing lithological borehole logs were collected and analysed with Jewel Suite 2011 software. A geostatistical method sequential indicator simulation was used to create spatial distribution of five hydrofacies at the Ljubljana polje aquifer. The layers/lenses that are bigger than 0.07 km2 and have hydraulic conductivity lower than K = 10-7 m/s were defined as lenses that can potentially form perched aquifers. In the modelling area, two areas with higher concentration of lenses with low hydraulic conductivity were defined. At those areas, according to the borehole data, perched aquifers appear few meters below surface to the depth around 30 m. At the other parts of the model area lenses with low hydraulic conductivity are less abundant. With spatial information (lateral and vertical extension) of perched aquifers in Ljubljana polje improvement of existing hydrogeological models can be made which can help to improve the qualitative and quantitative status of the Ljubljana polje main aquifer.

Competition between nonindigenous ruffe and native yellow perch in laboratory studies

USGS Publications Warehouse

Savino, Jacqueline F.; Kolar, Cynthia S.

1996-01-01

The ruffe Gymnocephalus cernuus is a European percid that was accidently introduced in Duluth Harbor, Lake Superior. This nonindigenous species is closely related to yellow perch Perca flavescens, and because the two species have similar diets and habitat requirements, they are potential competitors. Laboratory studies in aquaria and pools were conducted to determine whether ruffe can compete with yellow perch for food. Ruffe had capture rates similar to those of yellow perch when food was unlimited. Ruffe spent more time than yellow perch over a feeding container before leaving it and searching again, and they also required less time to ingest (or handle) prey. However, the presence of yellow perch shortened the time ruffe spent over foraging areas when food was more limited. In addition, yellow perch were more active than ruffe, as indicated by their more frequent visits to a feeding container. Hence, the outcome of exploitative competition was not conclusive; ruffe appear to have the advantage in some behaviors, yellow perch in others. Ruffe were much more aggressive than yellow perch, and interference competition may be important in the interactions between these species. Our results indicate that ruffe might compete with native yellow perch.

Field Verification of Stable Perched Groundwater in Layered Bedrock Uplands

USGS Publications Warehouse

Carter, J.T.; Gotkowitz, M.B.; Anderson, M.P.

2011-01-01

Data substantiating perched conditions in layered bedrock uplands are rare and have not been widely reported. Field observations in layered sedimentary bedrock in southwestern Wisconsin, USA, provide evidence of a stable, laterally extensive perched aquifer. Data from a densely instrumented field site show a perched aquifer in shallow dolomite, underlain by a shale-and-dolomite aquitard approximately 25 m thick, which is in turn underlain by sandstone containing a 30-m-thick unsaturated zone above a regional aquifer. Heads in water supply wells indicate that perched conditions extend at least several kilometers into hillsides, which is consistent with published modeling studies. Observations of unsaturated conditions in the sandstone over a 4-year period, historical development of the perched aquifer, and perennial flow from upland springs emanating from the shallow dolomite suggest that perched groundwater is a stable hydrogeologic feature under current climate conditions. Water-table hydrographs exhibit apparent differences in the amount and timing of recharge to the perched and regional flow systems; steep hydraulic gradients and tritium and chloride concentrations suggest there is limited hydraulic connection between the two. Recognition and characterization of perched flow systems have practical importance because their groundwater flow and transport pathways may differ significantly from those in underlying flow systems. Construction of multi-aquifer wells and groundwater withdrawal in perched systems can further alter such pathways. ?? 2010 The Author(s). Journal compilation ?? 2010 National Ground Water Association.

Influence of perched groundwater on base flow

USGS Publications Warehouse

Niswonger, Richard G.; Fogg, Graham E.

2008-01-01

Analysis with a three‐dimensional variably saturated groundwater flow model provides a basic understanding of the interplay between streams and perched groundwater. A simplified, layered model of heterogeneity was used to explore these relationships. Base flow contribution from perched groundwater was evaluated with regard to varying hydrogeologic conditions, including the size and location of the fine‐sediment unit and the hydraulic conductivity of the fine‐sediment unit and surrounding coarser sediment. Simulated base flow was sustained by perched groundwater with a maximum monthly discharge in excess of 15 L/s (0.6 feet3/s) over the length of the 2000‐m stream reach. Generally, the rate of perched‐groundwater discharge to the stream was proportional to the hydraulic conductivity of sediment surrounding the stream, whereas the duration of discharge was proportional to the hydraulic conductivity of the fine‐sediment unit. Other aspects of the perched aquifer affected base flow, such as the depth of stream penetration and the size of the fine‐sediment unit. Greater stream penetration decreased the maximum base flow contribution but increased the duration of contribution. Perched groundwater provided water for riparian vegetation at the demand rate but reduced the duration of perched‐groundwater discharge nearly 75%.

A health assessment of high status Christian burials recovered from the Roman-Byzantine archeological site of Elaiussa Sebaste, Turkey.

PubMed

Paine, R R; Vargiu, R; Coppa, A; Morselli, C; Schneider, E E

2007-01-01

The purpose of this study is to assess the state of health of 116 individuals whose remains were excavated from Byzantine period burials underneath the floor of an important Christian basilica from the site of Elaiussa Sebaste, Turkey. Elaiussa Sebaste was a Mediterranean coastal community, which began as a Roman town and continued as an early Christian Byzantine community until the end of the 7th century AD. The burials date from the middle of the 6th through the middle of the 7th centuries AD. We attempt to determine how high social status has influenced the type and frequency of skeletal lesions exhibited in this sample. All strata of this population show a number of chronic and acute health problems as indicated by skeletal lesions. Yet, only the frequency of degenerative joint disease (DJD) differs by sex, with males exhibiting a higher rate of DJD than females, p=0.09. There is no difference in the frequency of trauma among adult males and females. Non-specific skeletal lesions (cribra orbitalia, porotic hyperostosis, and periostitis) often associated with dietary and general stressors, but also with specific systemic diseases, are common in both sexes. The sub-adults primarily exhibit periostitis of the long bones and do not show skeletal lesions specific to malaria. It seems that high social ranking did not prevent serious ailments from affecting the health of individuals living in the Elaiussa Sebaste community.

Anadromous alewives, Alosa pseudoharengus, as prey for white perch, Morone americana

USGS Publications Warehouse

Moring, J.R.; Mink, L.H.

2002-01-01

The reintroduction of anadromous alewives, Alosa pseudoharengus, to their historic habitats in the inland waters of the United States and Canada, has prompted concerns about possible interactions with a popular sport fish, white perch, Morone americana. Both species are now widely distributed in northeastern North America. Diets of white perch in Lake George, Maine, U.S.A., where alewives were absent, were monitored and compared with those of white perch populations that were sympatric with anadromous alewives in two coastal Maine lakes, Biscay Pond and North Pond. In the presence of introduced alewives, the diet of adult white perch became almost exclusively juvenile alewives by late summer in ponds where both species were present. White perch that were sympatric with alewives were more piscivorus than were Lake George white perch, which primarily consumed Cladocera. Not only were alewives the principal prey item in the diet of white perch in Biscay and North ponds, but adult alewives were largely cannibalistic by August. Thus, success of reintroducing anadromous alewives in waters containing white perch may be negatively impacted by predation as well as cannibalism.

Food habits of stunted and non-stunted white perch (Morone americana)

USGS Publications Warehouse

Gosch, N.J.C.; Stittie, J.R.; Pope, K.L.

2010-01-01

We studied food habits of white perch (Morone americana) from two populations with different stable states (stunted [Branched Oak Lake, Nebraska] and nonstunted [Pawnee Lake, Nebraska]) to determine if change in food habits of white perch is likely to occur in situations where a stunted white perch population is altered to a nonstunted state and vice versa. Three approaches were used to quantitatively describe seasonal (spring = March-May, summer = June-August, autumn = September-November) diets of white perch - 1) frequency of occurrence, 2) percentage of composition by volume, and 3) mean stomach fullness. White perch diets were dominated by cladocerans and dipterans in both reservoirs during all seasons. Fish egg predation was similar between reservoirs, and white perch rarely consumed fishes in either the stunted or the non-stunted population. Shifting a white perch population between stunted and non-stunted states will likely cause little or no change in food habits; fish in both states will primarily consume invertebrates.

Numerical modeling of perched water under Yucca Mountain, Nevada

USGS Publications Warehouse

Hinds, J.J.; Ge, S.; Fridrich, C.J.

1999-01-01

The presence of perched water near the potential high-level nuclear waste repository area at Yucca Mountain, Nevada, has important implications for waste isolation. Perched water occurs because of sharp contrasts in rock properties, in particular between the strongly fractured repository host rock (the Topopah Spring welded tuff) and the immediately underlying vitrophyric (glassy) subunit, in which fractures are sealed by clays that were formed by alteration of the volcanic glass. The vitrophyre acts as a vertical barrier to unsaturated flow throughout much of the potential repository area. Geochemical analyses (Yang et al. 1996) indicate that perched water is relatively young, perhaps younger than 10,000 years. Given the low permeability of the rock matrix, fractures and perhaps fault zones must play a crucial role in unsaturated flow. The geologic setting of the major perched water bodies under Yucca Mountain suggests that faults commonly form barriers to lateral flow at the level of the repository horizon, but may also form important pathways for vertical infiltration from the repository horizon down to the water table. Using the numerical code UNSAT2, two factors believed to influence the perched water system at Yucca Mountain, climate and fault-zone permeability, are explored. The two-dimensional model predicts that the volume of water held within the perched water system may greatly increase under wetter climatic conditions, and that perched water bodies may drain to the water table along fault zones. Modeling results also show fault flow to be significantly attenuated in the Paintbrush Tuff non-welded hydrogeologic unit.

Variation in habitat use by juvenile Acadian redfish, Sebastes fasciatus

USGS Publications Warehouse

Auster, P.J.; Lindholm, J.; Valentine, P.C.

2003-01-01

A basic paradigm in behavioral ecology is that organisms expand their distribution as preferred sites become saturated with individuals that reduce the availability of resources (e.g., shelter, prey) on a per capita basis. Previous fish community studies at Stellwagen Bank National Marine Sanctuary have shown that juvenile Acadian redfish Sebastes fasciatus (20 cm TL) also occurred in dense cerianthid habitats. Two explanations for these distributions can be advanced. The simplest is that redfish use both boulder and cerianthid habitats on an encounter basis, regardless of habitat saturation or predation pressure. Alternatively, boulder reefs serve as recruitment habitats and cerianthid habitats serve as a conduit for redfish moving away from saturated boulder reef sites, essentially serving as elements of a 'redfish pump'.

Dynamics and Control of Three-Dimensional Perching Maneuver under Dynamic Stall Influence

NASA Astrophysics Data System (ADS)

Feroskhan, Mir Alikhan Bin Mohammad

Perching is a type of aggressive maneuver performed by the class 'Aves' species to attain precision point landing with a generally short landing distance. Perching capability is desirable on unmanned aerial vehicles (UAVs) due to its efficient deceleration process that potentially expands the functionality and flight envelope of the aircraft. This dissertation extends the previous works on perching, which is mostly limited to two-dimensional (2D) cases, to its state-of-the-art threedimensional (3D) variety. This dissertation presents the aerodynamic modeling and optimization framework adopted to generate unprecedented variants of the 3D perching maneuver that include the sideslip perching trajectory, which ameliorates the existing 2D perching concept by eliminating the undesirable undershoot and reliance on gravity. The sideslip perching technique methodically utilizes the lateral and longitudinal drag mechanisms through consecutive phases of yawing and pitching-up motion. Since perching maneuver involves high rates of change in the angles of attack and large turn rates, introduction of three internal variables thus becomes necessary for addressing the influence of dynamic stall delay on the UAV's transient post-stall behavior. These variables are then integrated into a static nonlinear aerodynamic model, developed using empirical and analytical methods, and into an optimization framework that generates a trajectory of sideslip perching maneuver, acquiring over 70% velocity reduction. An impact study of the dynamic stall influence on the optimal perching trajectories suggests that consideration of dynamic stall delay is essential due to the significant discrepancies in the corresponding control inputs required. A comparative study between 2D and 3D perching is also conducted to examine the different drag mechanisms employed by 2D and 3D perching respectively. 3D perching is presented as a more efficient deceleration technique with respect to spatial costs and

Access to Barrier Perches Improves Behavior Repertoire in Broilers

PubMed Central

Ventura, Beth A.; Siewerdt, Frank; Estevez, Inma

2012-01-01

Restriction of behavioral opportunities and uneven use of space are considerable welfare concerns in modern broiler production, particularly when birds are kept at high densities. We hypothesized that increased environmental complexity by provision of barrier perches would help address these issues by encouraging perching and enhancing use of the pen space across a range of stocking densities. 2,088 day-old broiler chicks were randomly assigned to one of the following barrier and density treatment combinations over four replications: simple barrier, complex barrier, or control (no barrier) and low (8 birds/m2), moderate (13 birds/m2), or high (18 birds/m2) density. Data were collected on focal birds via instantaneous scan sampling from 2 to 6 weeks of age. Mean estimates per pen for percent of observations seen performing each behavior, as well as percent of observations in the pen periphery vs. center, were quantified and submitted to an analysis of variance with week as the repeated measure. Barrier perches, density and age affected the behavioral time budget of broilers. Both simple and complex barrier perches effectively stimulated high perching rates. Aggression and disturbances were lower in both barrier treatments compared to controls (P<0.05). Increasing density to 18 birds/m2 compared to the lower densities suppressed activity levels, with lower foraging (P<0.005), decreased perching (P<0.0001) and increased sitting (P = 0.001) earlier in the rearing period. Disturbances also increased at higher densities (P<0.05). Use of the central pen area was higher in simple barrier pens compared to controls (P<0.001), while increasing density above 8 birds/m2 suppressed use of the central space (P<0.05). This work confirms some negative effects of increasing density and suggests that barrier perches have the potential to improve broiler welfare by encouraging activity (notably by providing accessible opportunities to perch), decreasing aggression and disturbances

Branching out in locomotion: the mechanics of perch use in birds and primates.

PubMed

Bonser, R H

1999-06-01

Many animals use thin perches, such as the branches of trees, as locomotory substrates. In this paper, I have reviewed the literature concerned with measurements of locomotory forces made by birds and primates on thin and flexible substrates. Through a knowledge of the locomotory forces exerted by animals when using different substrates, the mechanical cost of their use can be established. We are just beginning to learn about the magnitude and patterns of force production in various branch-using vertebrates, primarily as a result of the development of instrumented perches. Instrumented perches have been designed to measure the forces produced by birds and primates when leaping from rigid and flexible horizontal and flexible vertical perches, and also from instrumented handgrips during brachiation. The development of these techniques for birds and primates allows us to compare the way in which they use perches as locomotory substrates. In both birds and primates, the magnitudes of landing forces are smaller than those during take-off. Two explanations have been proposed; the difference is either a consequence of perch compliance or it is a strategic decision to be cautious of 'new' perches. Leaps from flexible perches may be somewhat inefficient because considerable energy is dissipated in bending the perch, and this energy may remain unrecovered when the animal leaves contact with the perch.

Bioaccumulation of decamethylcyclopentasiloxane in perch in Swedish lakes.

PubMed

Kierkegaard, Amelie; Bignert, Anders; McLachlan, Michael S

2013-10-01

Decamethylcyclopentasiloxane (D5), a high production volume chemical used in personal care products, enters the environment both via air and sewage treatment plant (STP) recipients. It has been found in fish, and there is concern that it may be a bioaccumulative substance. In this work D5 was analyzed in perch from six Swedish lakes that did not receive STP effluent, and in perch and sediment from six lakes that received STP effluent. In the lakes receiving the STP effluent, the D5 concentrations in sediment varied over three orders of magnitude and were correlated with the number of persons connected to the STP normalized to the surface area of the receiving body. In the lakes not receiving effluent, the D5 levels in perch were all below the LOQ, while D5 was above the LOQ in almost all perch from lakes that received effluent. The D5 concentrations in perch and sediment from the lakes receiving STP effluent were correlated. This shows that STP effluent is a much more important source of D5 to aquatic ecosystems than atmospheric deposition, and that the risk of adverse effects of D5 on aquatic life will be greatest in small recipients receiving large amounts of STP effluent. The bioaccumulation of D5 was compared to that of PCB 180 on the basis of multimedia bioaccumulation factors (mmBAFs), which describe the fraction of the contaminant present in the whole aquatic environment (i.e. water and surface sediment) that is transferred to the fish. In four of the six lakes the mmBAF of D5 was >0.3 of the mmBAF of PCB 180. Given that PCB 180 is a known highly bioaccumulative chemical, this indicates that the bioaccumulation of D5 in perch is considerable. Copyright © 2012 Elsevier Ltd. All rights reserved.

Domestication drive the changes of immune and digestive system of Eurasian perch (Perca fluviatilis).

PubMed

Chen, Xiaowen; Wang, Jun; Qian, Long; Gaughan, Sarah; Xiang, Wei; Ai, Tao; Fan, Zhenming; Wang, Chenghui

2017-01-01

Domestication has altered a variety of traits within the Eurasian perch (Perca fluviatilis), including phenotypic, physiological and behavioral traits of Eurasian perch (Perca fluviatilis). Little is known, however, about the genetic changes between domesticated and wild Eurasian perch. In this study, we assembled a high-quality de novo reference transcriptome and identified differentially expressed genes between wild and domesticated Eurasian perch. A total of 113,709 transcripts were assembled, and 58,380 transcripts were annotated. Transcriptomic comparison revealed 630 differentially expressed genes between domesticated and wild Eurasian perch. Within domesticated Eurasian perch there were 412 genes that were up-regulated including MHCI, MHCII, chia, ighm within immune system development. There were 218 genes including try1, ctrl, ctrb, cela3b, cpa1 and cpb1, which were down-regulated that were associated with digestive processes. Our results indicated domestication drives the changes of immune and digestive system of Eurasian perch. Our study not only provide valuable genetic resources for further studies in Eurasian perch, but also provide novel insights into the genetic basis of physiological changes in Eurasian perch during domestication process.

Ecology and population status of trout-perch (Percopsis omiscomaycus) in western Lake Erie

USGS Publications Warehouse

Kocovsky, Patrick; Stoneman, Andrea T.; Kraus, Richard T.

2014-01-01

Trout-perch Percopsis omiscomaycus is among the most abundant benthic species in Lake Erie, but comparatively little is known about its ecology. Although others have conducted extensive studies on trout-perch ecology, those efforts predated invasions of white perch Morone americana, Dreissena spp., Bythotrephes longimanus and round goby Neogobius melanostomus, suggesting the need to revisit past work. Trout-perch were sampled with bottom trawls at 56 sites during June and September 2010. We examined diets, fecundity, average annual mortality, sex ratio, and long-term population trends at sites sampled since 1961. Trout-perch abundance fluctuated periodically, with distinct shorter- (4-year) and longer-term (over period of 50 years) fluctuations. Males had higher average annual mortality than females. Both sexes were equally abundant at age 0, but females outnumbered males 4:1 by age 2. Diets of trout-perch were dominated by macroinvertebrates, particularly chironomids and Hexagenia sp. Size distributions of trout-perch eggs varied widely and exhibited multiple modes indicative of protracted batch spawning. A review of the few other studies of trout-perch revealed periodic fluctuations in sex ratio of adults, which in light of our evidence of periodicity in abundance suggests the potential for sex-ratio-mediated intrinsic population regulation. Despite the introduction of numerous invasive species in Lake Erie, trout-perch remain one of the most abundant benthic invertivores and the population is relatively stable.

Domestication drive the changes of immune and digestive system of Eurasian perch (Perca fluviatilis)

PubMed Central

Chen, Xiaowen; Wang, Jun; Qian, Long; Gaughan, Sarah; Xiang, Wei; Ai, Tao; Fan, Zhenming; Wang, Chenghui

2017-01-01

Domestication has altered a variety of traits within the Eurasian perch (Perca fluviatilis), including phenotypic, physiological and behavioral traits of Eurasian perch (Perca fluviatilis). Little is known, however, about the genetic changes between domesticated and wild Eurasian perch. In this study, we assembled a high-quality de novo reference transcriptome and identified differentially expressed genes between wild and domesticated Eurasian perch. A total of 113,709 transcripts were assembled, and 58,380 transcripts were annotated. Transcriptomic comparison revealed 630 differentially expressed genes between domesticated and wild Eurasian perch. Within domesticated Eurasian perch there were 412 genes that were up-regulated including MHCI, MHCII, chia, ighm within immune system development. There were 218 genes including try1, ctrl, ctrb, cela3b, cpa1 and cpb1, which were down-regulated that were associated with digestive processes. Our results indicated domestication drives the changes of immune and digestive system of Eurasian perch. Our study not only provide valuable genetic resources for further studies in Eurasian perch, but also provide novel insights into the genetic basis of physiological changes in Eurasian perch during domestication process. PMID:28257494

Habitat Suitability Index Models: Yellow perch

USGS Publications Warehouse

Krieger, Douglas A.; Terrell, James W.; Nelson, Patrick C.

1983-01-01

A review and synthesis of existing information were used to develop riverine and lacustrine habitat models for yellow perch (Perca flavescens). The models are scaled to produce an index of habitat suitability between 0 (unsuitable habitat) to 1 (optimally suitable habitat) for riverine, lacustrine, and palustrine habitat in the 48 contiguous United States. Habitat Suitability Indexes (HSI's) are designed for use with the Habitat Evaluation Procedures developed by the U.S. Fish and Wildlife Service. Also included are discussions of Suitability Index (SI) curves as used in the Instream Flow Incremental Methodology (IFIM) and SI curves available for an IFIM analysis of yellow perch habitat.

The acute toxicity of the metaldehyde on the climbing perch

NASA Astrophysics Data System (ADS)

Wahida Mohamad Ismail, Syamimi; Aini Dahalan, Farrah; Zakaria, Ammar; Mad Shakaff, Ali Yeon; Aqlima Ahmad, Siti; Shukor, Mohd Yunus Abd; Khalizan Sabullah, Mohd; Khalil, Khalilah Abdul; Jalil, Mohd Faizal Ab

2018-03-01

In Asia, Climbing perch (Anabas testudineus) is commonly found in paddy fields and irrigation systems. Due to its habitat, Climbing perch is exposed to toxic pesticides used in paddy fields such as metaldehyde which is one of the most widely used molluscicide. This study aims to determine the acute toxicity Lethal Concentration50 (LC50) of metaldehyde and its effect on the behaviour and physical changes of the Climbing perch. The fish mortality responses to six different metaldehyde concentrations ranging from 180 to 330 mg/L were investigated. The 96-h LC50 values were determined and analysed using three different analysis methods which is arithmetic, logarithmic and probit graphic. The LC50 values obtained in this study were 239, 234 and 232 mg/L, respectively. After 96-h of exposure to metaldehyde, the fish showed a series of abnormal behavioural response in all cases: imbalance position, and restlessness of movement. The LC50 values show that metaldehyde is moderately toxic to the Climbing perch indicating that metaldehyde is not destructive to Climbing perch. However, long term exposure of aquatic organisms to the metaldehyde means a continuous health risk for the fish population as they are more vulnerable and it is on high risk for human to consume this toxicated fishes.

Demonstrations of bio-inspired perching landing gear for UAVs

NASA Astrophysics Data System (ADS)

Tieu, Mindy; Michael, Duncan M.; Pflueger, Jeffery B.; Sethi, Manik S.; Shimazu, Kelli N.; Anthony, Tatiana M.; Lee, Christopher L.

2016-04-01

Results are presented which demonstrate the feasibility and performance of two concepts of biologically-inspired landing-gear systems that enable bird-sized, unmanned aerial vehicles (UAV's) to land, perch, and take-off from branchlike structures and/or ledges. The first concept follows the anatomy of birds that can grasp ahold of a branch and perch as tendons in their legs are tensioned. This design involves a gravity-activated, cable-driven, underactuated, graspingfoot mechanism. As the UAV lands, its weight collapses a four-bar linkage pulling a cable which curls two opposing, multi-segmented feet to grasp the landing target. Each foot is a single, compliant mechanism fabricated by simultaneouly 3D-printing a flexible thermo-plastic and a stiffer ABS plastic. The design is optimized to grasp structures over a range of shapes and sizes. Quasi-static and flight tests of this landing gear affixed to RC rotorcraft (24 cm to 550 cm in diameter) demonstrate that the aircraft can land, perch, and take-off from a tree branch, rectangular wood board, PVC pipe, metal hand rail, chair armrest, and in addition, a stone wall ledge. Stability tests show that perching is maintained under base and wind disturbances. The second design concept, inspired by roosting bats, is a two-material, 3D-printed hooking mechanism that enables the UAV to stably suspend itself from a wire or small-diameter branch. The design balances structural stiffness for support and flexibility for the perching process. A flight-test demonstrates the attaching and dis-engaging of a small, RC quadcopter from a suspended line.

Reproductive health of yellow perch Perca flavescens in selected tributaries of the Chesapeake Bay.

PubMed

Blazer, Vicki S; Pinkney, Alfred E; Jenkins, Jill A; Iwanowicz, Luke R; Minkkinen, Steven; Draugelis-Dale, Rassa O; Uphoff, James H

2013-03-01

Reduced recruitment of yellow perch has been noted for a number of years in certain urbanized watersheds (South and Severn Rivers) of the Chesapeake Bay. Other rapidly developing watersheds such as Mattawoman Creek are more recently showing evidence of reduced recruitment of anadromous fishes. In this study, we used a battery of biomarkers to better document the reproductive health of adult yellow perch collected during spring spawning in 2007-2009. Perch were collected in the South and Severn Rivers, Mattawoman Creek and the less developed Choptank and Allen's Fresh watersheds for comparison. Gonadosomatic indices, plasma reproductive hormone concentrations, plasma vitellogenin concentrations and gonad histology were evaluated in mature perch of both sexes. In addition, sperm quantity (cell counts) and quality (total and progressive motility, spermatogenic stage and DNA integrity), were measured in male perch. Many of these biomarkers varied annually and spatially, with some interesting statistical results and trends. Male perch from the Choptank and Allen's Fresh had generally higher sperm counts. In 2008 counts were significantly lower in the perch from the Severn when compared to other sites. The major microscopic gonadal abnormality in males was the proliferation of putative Leydig cells, observed in testes from Severn and less commonly, Mattawoman Creek perch. Observations that could significantly impact egg viability were an apparent lack of final maturation, abnormal yolk and thin, irregular zona pellucida. These were observed primarily in ovaries from Severn, South and less commonly Mattawoman Creek perch. The potential association of these observations with urbanization, impervious surface and chemical contaminants is discussed. Published by Elsevier B.V.

Reproductive health of yellow perch Perca flavescens in selected tributaries of the Chesapeake Bay

USGS Publications Warehouse

Blazer, Vicki; Pinkney, Alfred E.; Jenkins, Jill A.; Iwanowicz, Luke R.; Minkkinen, Steven; Draugelis-Dale, Rassa O.; Uphoff, James H.

2013-01-01

Reduced recruitment of yellow perch has been noted for a number of years in certain urbanized watersheds (South and Severn Rivers) of the Chesapeake Bay. Other rapidly developing watersheds such as Mattawoman Creek are more recently showing evidence of reduced recruitment of anadromous fishes. In this study, we used a battery of biomarkers to better document the reproductive health of adult yellow perch collected during spring spawning in 2007–2009. Perch were collected in the South and Severn Rivers, Mattawoman Creek and the less developed Choptank and Allen's Fresh watersheds for comparison. Gonadosomatic indices, plasma reproductive hormone concentrations, plasma vitellogenin concentrations and gonad histology were evaluated in mature perch of both sexes. In addition, sperm quantity (cell counts) and quality (total and progressive motility, spermatogenic stage and DNA integrity), were measured in male perch. Many of these biomarkers varied annually and spatially, with some interesting statistical results and trends. Male perch from the Choptank and Allen's Fresh had generally higher sperm counts. In 2008 counts were significantly lower in the perch from the Severn when compared to other sites. The major microscopic gonadal abnormality in males was the proliferation of putative Leydig cells, observed in testes from Severn and less commonly, Mattawoman Creek perch. Observations that could significantly impact egg viability were an apparent lack of final maturation, abnormal yolk and thin, irregular zona pellucida. These were observed primarily in ovaries from Severn, South and less commonly Mattawoman Creek perch. The potential association of these observations with urbanization, impervious surface and chemical contaminants is discussed.

Woody structure facilitates invasion of woody plants by providing perches for birds.

PubMed

Prather, Chelse M; Huynh, Andrew; Pennings, Steven C

2017-10-01

Woody encroachment threatens prairie ecosystems globally, and thus understanding the mechanisms that facilitate woody encroachment is of critical importance. Coastal tallgrass prairies along the Gulf Coast of the US are currently threatened by the spread of several species of woody plants. We studied a coastal tallgrass prairie in Texas, USA, to determine if existing woody structure increased the supply of seeds from woody plants via dispersal by birds. Specifically, we determined if (i) more seedlings of an invasive tree ( Tridacia sebifera ) are present surrounding a native woody plant ( Myrica cerifera ); (ii) wooden perches increase the quantity of seeds dispersed to a grassland; and (iii) perches alter the composition of the seed rain seasonally in prairie habitats with differing amounts of native and invasive woody vegetation, both underneath and away from artificial wooden perches. More T. sebifera seedlings were found within M. cerifera patches than in graminoid-dominated areas. Although perches did not affect the total number of seeds, perches changed the composition of seed rain to be less dominated by grasses and forbs. Specifically, 20-30 times as many seeds of two invasive species of woody plants were found underneath perches independent of background vegetation, especially during months when seed rain was highest. These results suggest that existing woody structure in a grassland can promote further woody encroachment by enhancing seed dispersal by birds. This finding argues for management to reduce woody plant abundance before exotic plants set seeds and argues against the use of artificial perches as a restoration technique in grasslands threatened by woody species.

Fish community dynamics in northeastern Lake Ontario with emphasis on the growth and reproductive success of yellow perch (Perca flavescens) and white perch (Morone americana), 1978 to1997

USGS Publications Warehouse

O'Gorman, Robert; Burnett, John A.D.

2001-01-01

Fishes were assessed in Guffin, Chaumount, and Black River bays in northeastern Lake Ontario with a 7.9-m (headrope) bottom trawl during late September and early October, 1978 to 1997. Fish density declined in the early 1990s with sharp declines in abundance of spottail shiner (Notropis hudsonius), trout-perch (Percopsis omiscomaycus), and johnny darter (Etheostoma nigrum) occurring in 1993 to 1995. Rising numbers of piscivores, walleye (Stizostedion vitreum) and double-crested cormorant (Phalacrocorax auritus), increased predation pressure, presumably acting in concert with oligotrophication to lower fish density, particularly after 1991 when large numbers of adult alewife (Alosa pseudoharengus) no longer migrated to the northeast basin in spring. Annual mortality of yellow perch (Perca flavescens) from age 2 to 5 rose from 33% in 1980–83 to 65% in 1992–95 and was positively related to piscivore numbers (P = 0.01, r = 0.96, n = 5). Annual mortality of yellow perch from age 0 to 2 also peaked in 1992–95. Abundance of yellow perch YOY in fall varied 40 fold and was not related to water warming in spring (P = 0.45, r = −0.19, n = 18) but was negatively related to the abundance of adult alewives in spring (P = 0.04, r = −0.49, n = 18). Although yellow perch produced moderate to strong year classes each year during 1991–95, stock size failed to increase because of rapidly accelerating mortality. Fully 85% of the variation in mean length of yellow perch YOY was explained by a multiple regression model which included YOY abundance, mean total phosphorus, and cumulative degree days > 13.5°C (P < 0.01, n = 15). Abundance of white perch (Morone americana) YOY varied nearly 200 fold and was not related to water warming or spring alewife abundance (P > 0.15). Variation in mean length of white perch YOY was related to cumulative degree days > 15°C (P < 0.01, r = 0.69).

First isolation of a rhabdovirus from perch Perca fluviatilis in Switzerland.

PubMed

Wahli, Thomas; Bellec, Laure; von Siebenthal, Beat; Cabon, Joëlle; Schmidt-Posthaus, Heike; Morin, Thierry

2015-10-16

Perca fluviatilis is a fish species of increasing interest to the Swiss fish farming industry. In recent years, recirculation systems have been specifically set up to increase production. In one of these farms, abnormal spiral swimming associated with elevated mortalities occurred in repeated batches of imported perch shortly after stocking on several occasions. No bacterial or parasitic etiology was detected, but a virus grown in bluegill fry (BF-2) cells was identified as perch rhabdovirus. Subsequent investigations of other samples suggested a viral tropism for the central nervous system (CNS). Phylogenetic analysis of the partial N and entire G gene sequences positioned this isolate in genogroup C of the species Perch rhabdovirus, with high nucleotide and amino acid (aa) sequence identities with the DK5533 strain isolated in Denmark in 1989. Comparative studies using other closely related isolates allowed the distinction of 2 serological patterns among perch rhabdoviruses and the identification of a proline substitution by a serine in position 147 of the glycoprotein potentially involved in antigenic differentiation. Even if perch imported onto the farm tested negative by virus isolation prior to transport, they may have been the origin of this outbreak since CNS tissue was not included in the samples that were analyzed. Another possibility might be a sub-clinical infection with a viral load in resident fish too low to be detected. This study reports the first isolation of a perch rhabdovirus in Switzerland, and emphasizes the necessity of optimizing diagnostic tools that facilitate better control of the risks associated with fish translocation.

Water transparency drives intra-population divergence in Eurasian Perch (Perca fluviatilis).

PubMed

Bartels, Pia; Hirsch, Philipp E; Svanbäck, Richard; Eklöv, Peter

2012-01-01

Trait combinations that lead to a higher efficiency in resource utilization are important drivers of divergent natural selection and adaptive radiation. However, variation in environmental features might constrain foraging in complex ways and therefore impede the exploitation of critical resources. We tested the effect of water transparency on intra-population divergence in morphology of Eurasian perch (Perca fluviatilis) across seven lakes in central Sweden. Morphological divergence between near-shore littoral and open-water pelagic perch substantially increased with increasing water transparency. Reliance on littoral resources increased strongly with increasing water transparency in littoral populations, whereas littoral reliance was not affected by water transparency in pelagic populations. Despite the similar reliance on pelagic resources in pelagic populations along the water transparency gradient, the utilization of particular pelagic prey items differed with variation in water transparency in pelagic populations. Pelagic perch utilized cladocerans in lakes with high water transparency and copepods in lakes with low water transparency. We suggest that under impaired visual conditions low utilization of littoral resources by littoral perch and utilization of evasive copepods by pelagic perch may lead to changes in morphology. Our findings indicate that visual conditions can affect population divergence in predator populations through their effects on resource utilization.

Water Transparency Drives Intra-Population Divergence in Eurasian Perch (Perca fluviatilis)

PubMed Central

Bartels, Pia; Hirsch, Philipp E.; Svanbäck, Richard; Eklöv, Peter

2012-01-01

Trait combinations that lead to a higher efficiency in resource utilization are important drivers of divergent natural selection and adaptive radiation. However, variation in environmental features might constrain foraging in complex ways and therefore impede the exploitation of critical resources. We tested the effect of water transparency on intra-population divergence in morphology of Eurasian perch (Perca fluviatilis) across seven lakes in central Sweden. Morphological divergence between near-shore littoral and open-water pelagic perch substantially increased with increasing water transparency. Reliance on littoral resources increased strongly with increasing water transparency in littoral populations, whereas littoral reliance was not affected by water transparency in pelagic populations. Despite the similar reliance on pelagic resources in pelagic populations along the water transparency gradient, the utilization of particular pelagic prey items differed with variation in water transparency in pelagic populations. Pelagic perch utilized cladocerans in lakes with high water transparency and copepods in lakes with low water transparency. We suggest that under impaired visual conditions low utilization of littoral resources by littoral perch and utilization of evasive copepods by pelagic perch may lead to changes in morphology. Our findings indicate that visual conditions can affect population divergence in predator populations through their effects on resource utilization. PMID:22912895

Effects of intermittent chlorination on rainbow trout and yellow perch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brooks, A.S.; Seegert, G.L.

1977-05-01

Rainbow trout, Salmo gairdneri, and yellow perch, Perca flavescens, were exposed to residual chlorine for single 30-minute and triple 5-minute doses. Tests were conducted at 10, 15, and 20 C with both species plus 25 and 30 C for the perch. Single exposure 30-minute LC50 values for the perch ranged from 0.70 mg/liter at 30 C to 8.0 mg/liter at 10 C. Triple 5-minute exposure LC50 values for the perch were 22.6 and 9.0 mg/liter at 10 and 20 C, respectively. Rainbow trout 30-minute LC50 values were 0.99 and 0.94 mg/liter at 10 and 15 C, respectively. Two groups ofmore » trout tested at 20 C yielded 30-minute LC50 values of 0.60 and 0.43 mg/liter. Triple exposure 5-minute LC50 values for the trout were 2.87 mg/liter at 10 C and 1.65 mg/liter at 20 C. Mortality occurred immediately after exposure to chlorine in the 30-minute perch tests at 10 and 15 C, but was delayed 2 to 12 hours at the higher temperatures. This pattern was reversed in the 5-minute triple exposure tests. Rainbow trout exhibited rapid mortality in all tests except the 10 C triple exposure series where mortality was delayed 12 to 24 hours. For both species, concentrations resulting in no mortality were approximately one-half the LC50 value.« less

2,3,7,8-tetrachlorodibenzo-p-dioxin toxicity in yellow perch (Perca flavescens)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spitsbergen, J.M.; Kleeman, J.M.; Peterson, R.E.

1988-01-01

Growth, mortality and morphologic lesions in juvenile, hatchery-reared yellow perch, Perca flavescens, were studied after treatment with graded single doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, 1-125 ..mu..g/kg, intraperitoneally). TCDD doses of 25 and 125 ..mu..g/kg caused 95% mortality by 28 d after treatment, without decreasing body weight. A TCDD dose of 5 ..mu..g/kg resulted in progressive loss of body weight with cumulative mortality of 80% by 80 d posttreatment. Periodic handling stress did not affect the time course of mortality or cumulative percent lethality in TCDD-treated perch. Fin necrosis, petechial cutaneous hemorrhage, and ascites occurred in perch treated with 5 ..mu..g/kg ormore » more of TCDD. Thymic atrophy, decreased hematopoiesis in the head kidney, fibrinous pericarditis, focal myocardial necrosis, submucosal gastric edema, and hyperplasia of the epithelium of gill filaments and lamellae occurred in perch dosed with 25 or 125 ..mu..g/kg. Dose-related splenic lymphoid depletion occurred in perch receiving 5 ..mu..g/kg or more TCDD, and hepatocycte lipidosis occurred in groups treated with doses of 1 ..mu..g/kg or more TCDD. Thus yellow perch are as responsive to the acute toxic effects of TCDD as some of the more sensitive mammalian species, and neither loss of body weight nor histologic lesions in TCDD-treated perch are sufficient to explain mortality.« less

Letter Report: Stable Hydrogen and Oxygen Isotope Analysis of B-Complex Perched Water Samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Brady D.; Moran, James J.; Nims, Megan K.

Fine-grained sediments associated with the Cold Creek Unit at Hanford have caused the formation of a perched water aquifer in the deep vadose zone at the B Complex area, which includes waste sites in the 200-DV-1 Operable Unit and the single-shell tank farms in Waste Management Area B-BX-BY. High levels of contaminants, such as uranium, technetium-99, and nitrate, make this aquifer a continuing source of contamination for the groundwater located a few meters below the perched zone. Analysis of deuterium ( 2H) and 18-oxygen ( 18O) of nine perched water samples from three different wells was performed. Samples represent timemore » points from hydraulic tests performed on the perched aquifer using the three wells. The isotope analyses showed that the perched water had δ 2H and δ 18O ratios consistent with the regional meteoric water line, indicating that local precipitation events at the Hanford site likely account for recharge of the perched water aquifer. Data from the isotope analysis can be used along with pumping and recovery data to help understand the perched water dynamics related to aquifer size and hydraulic control of the aquifer in the future.« less

Identification of gender in yellow perch Perca flavescens using external morphology

USDA-ARS?s Scientific Manuscript database

A non-lethal and rapid method for reliable identification of gender in yellow perch has been developed. On average, yellow perch females grow faster than males and undergo sexual maturity at an earlier age. Such size discrepancies in mixed culture situations pose difficulties with aquaculture produc...

The effect of perches in cages during pullet rearing and egg laying on hen performance, foot health, and plumage.

PubMed

Hester, P Y; Enneking, S A; Jefferson-Moore, K Y; Einstein, M E; Cheng, H W; Rubin, D A

2013-02-01

Enrichment of pullet cages with perches has not been studied. Our objective was to determine if access to metal perches during all or part of the life cycle of caged White Leghorns affected egg traits, foot health, and feather condition. Treatment 1 represented control chickens that never had access to perches during their life cycle. Treatment 2 hens had perches only during the egg laying phase of the life cycle (17 to 71 wk of age), whereas treatment 3 chickens had perches during the pullet phase (0 to 16.9 wk of age). Treatment 4 chickens always had access to perches (0 to 71 wk of age). Comparisons between chickens that always had perches with controls that never had perches showed similar performance relative to egg production, cracked eggs, egg weight, shell weight, % shell, and shell thickness. More dirty eggs occurred in laying cages with perches. Feed usage increased resulting in poorer feed efficiency in hens with perch exposure during the pullet phase with no effect during egg laying. Perches did not affect hyperkeratosis of toes and feet. The back claw at 71 wk of age broke less if hens had prior experience with perches during the pullet phase. In contrast, during egg laying, the back claw at 71 wk of age broke more due to the presence of perches in laying cages. Perches in laying cages resulted in shorter trimmed claws and improved back feather scores, but caused poorer breast and tail feather scores. In conclusion, enriching conventional cages with perches during the entire life cycle resulted in similar hen performance compared with controls. Fewer broken back claws but poorer feed efficiency occurred because of prior experience with perches as pullets. Perch presence during egg laying improved back feather scores with more trimmed nails but caused more dirty eggs, broken back claws, and poorer breast and tail feather scores. Although perches allow chickens to express their natural perching instinct, it was not without causing welfare problems.

Susceptibility of Koi and Yellow Perch to infectious hematopoietic necrosis virus by experimental exposure.

PubMed

Palmer, Alexander D; Emmenegger, Eveline J

2014-06-01

Infectious hematopoietic necrosis virus (IHNV) is a novirhabdoviral pathogen that originated in western North America among anadromous Pacific salmonids. Severe disease epidemics in the late 1970s resulting from IHNV's invasion into farmed Rainbow Trout Oncorhynchus mykiss in North America, Asia, and Europe emphasized IHNV's ability to adapt to new hosts under varying rearing conditions. Yellow Perch Perca flavescens and Koi Carp Cyprinus carpio (hereafter, "Koi") are aquaculture-reared fish that are highly valued in sport fisheries and the ornamental fish trade, respectively, but it is unknown whether these fish species are vulnerable to IHNV infection. In this study, we exposed Yellow Perch, Koi, and steelhead (anadromous Rainbow Trout) to IHNV by intraperitoneal injection (10(6) PFU/fish) and by immersion (5.7×10(5) PFU/mL) for 7 h, and monitored fish for 28 d. The extended immersion exposure and high virus concentrations used in the challenges were to determine if the tested fish had any level of susceptibility. After experimental exposure, Yellow Perch and Koi experienced low mortality (<6%) compared with steelhead (>35%). Virus was found in dead fish of all species tested and in surviving Yellow Perch by plaque assay and quantitative reverse transcription polymerase chain reaction (qPCR), with a higher prevalence in Yellow Perch than Koi. Infectious virus was also detected in Yellow Perch out to 5 d after bath challenge. These findings indicate that Yellow Perch and Koi are highly resistant to IHNV disease under the conditions tested, but Yellow Perch are susceptible to infection and may serve as possible virus carriers.

Susceptibility of Koi and Yellow Perch to infectious hematopoietic necrosis virus by experimental exposure

USGS Publications Warehouse

Palmer, Alexander D.; Emmenegger, Eveline J.

2014-01-01

Infectious hematopoietic necrosis virus (IHNV) is a novirhabdoviral pathogen that originated in western North America among anadromous Pacific salmonids. Severe disease epidemics in the late 1970s resulting from IHNV's invasion into farmed Rainbow Trout Oncorhynchus mykiss in North America, Asia, and Europe emphasized IHNV's ability to adapt to new hosts under varying rearing conditions. Yellow Perch Perca flavescens and Koi Carp Cyprinus carpio (hereafter, “Koi”) are aquaculture-reared fish that are highly valued in sport fisheries and the ornamental fish trade, respectively, but it is unknown whether these fish species are vulnerable to IHNV infection. In this study, we exposed Yellow Perch, Koi, and steelhead (anadromous Rainbow Trout) to IHNV by intraperitoneal injection (106 PFU/fish) and by immersion (5.7×105 PFU/mL) for 7 h, and monitored fish for 28 d. The extended immersion exposure and high virus concentrations used in the challenges were to determine if the tested fish had any level of susceptibility. After experimental exposure, Yellow Perch and Koi experienced low mortality (35%). Virus was found in dead fish of all species tested and in surviving Yellow Perch by plaque assay and quantitative reverse transcription polymerase chain reaction (qPCR), with a higher prevalence in Yellow Perch than Koi. Infectious virus was also detected in Yellow Perch out to 5 d after bath challenge. These findings indicate that Yellow Perch and Koi are highly resistant to IHNV disease under the conditions tested, but Yellow Perch are susceptible to infection and may serve as possible virus carriers.

Effects of dietary chromium exposure to rockfish, Sebastes schlegelii are ameliorated by ascorbic acid.

PubMed

Kim, Jun-Hwan; Kang, Ju-Chan

2017-05-01

Juvenile rockfish Sebastes schlegelii (mean length 10.8±1.4cm, and mean weight 31.7±3.6g) were exposed for 4 weeks with the different levels of dietary chromium (Cr 6+ ) at 0, 120 and 240mg/L and ascorbic acids (AsA) at 100, 200 and 400mg/L. Significant accumulation occurred in specific tissues and hematological parameters were altered: red blood cell count, hematocrit, and hemoglobin increased; plasma components were altered including calcium, glucose, cholesterol, total protein, glutamic oxalate transaminase, and glutamic pyruvate transaminase. However, magnesium and alkaline phosphatase concentrations were unchanged. Ascorbic acids reduced both chromium uptake into tissues and altered hematological parameters. Copyright © 2017. Published by Elsevier Inc.

Intraspecific variation in gill morphology of juvenile Nile perch, Lates niloticus, in Lake Nabugabo, Uganda

USGS Publications Warehouse

Paterson, Jaclyn A.; Chapman, Lauren J.; Schofield, Pamela J.

2010-01-01

Several studies have demonstrated intraspecific variation in fish gill size that relates to variation in dissolved oxygen (DO) availability across habitats. In Lake Nabugabo, East Africa, ecological change over the past 12 years has coincided with a shift in the distribution of introduced Nile perch such that a larger proportion of the population now inhabits waters in or near wetland ecotones where DO is lower than in open waters of the lake. In this study, we compared gill size of juvenile Nile perch between wetland and exposed (open-water) habitats of Lake Nabugabo in 2007, as well as between Nile perch collected in 1996 and 2007. For Nile perch of Lake Nabugabo [<20 cm total length (TL)], there was a significant habitat effect on some gill traits. In general, fish from wetland habitats were characterized by a longer total gill filament length and average gill filament length than conspecifics from exposed habitats. Nile perch collected from wetland areas in 2007 had significantly larger gills (total gill filament length) than Nile perch collected in 1996, but there was no difference detected between Nile perch collected from exposed sites in 2007 and conspecifics collected in 1996.

Development of perching behavior in 3 strains of pullets reared in furnished cages.

PubMed

Habinski, A M; Caston, L J; Casey-Trott, T M; Hunniford, M E; Widowski, T M

2017-03-01

Furnished rearing cages are becoming more widely available to replace conventional systems for pullets. To date, there is little information on how pullets develop perching behavior in furnished cages or how this varies among strains. The objective of this study was to evaluate the use of perches and a platform in a commercial furnished rearing "Combi-Cage" system by 3 pure-bred heritage strains of pullets (Rhode Island Red, Columbian Rock, and White Leghorn). Each cage had 4 elevated locations: one platform and 3 perches of differing heights and positions in the cage. The length of each cage was visually divided into 4 sections for observation. The number of birds using each section in each location was counted by one observer d per wk at 1200 h (d) from one to 14 wk of age and at 1600 h (night) right after lights were turned off from 4 to 14 wk of age. Mixed model repeated analyses were used to test effects of strain, age, and their interaction on the use of the platform, the 3 perches, and all 4 locations combined (vertical space use) at both time periods. GLM were used to compare overall use of the sections and locations. On average, pullets used vertical space more during the d than at night. There were also effects of age (P < 0.05) and strain (P < 0.05) on the use of the 4 locations in the cage at both time periods. Generally, the Columbian Rocks used the perches and platform the most, and Rhode Island Reds the least. The highest perch in the cage was rarely used and birds showed a preference for perching in sections that were closest to cage walls (P < 0.05). Differences across strains and low use of some perch locations indicate that the design of furnished rearing cages may still require improvements in order to ensure the furnishings are used by pullets as intended. © 2016 Poultry Science Association Inc.

Influence of Smallmouth Bass predation on recruitment of age-0 Yellow Perch in South Dakota glacial lakes

USGS Publications Warehouse

Dembkowski, Daniel J.; Willis, D.W.; Blackwell, B. G.; Chipps, Steven R.; Bacula, T. D.; Wuellner, M.R.

2015-01-01

We estimated the influence of predation by Smallmouth Bass Micropterus dolomieu on recruitment of age-0 Yellow Perch Perca flavescens in two northeastern South Dakota glacial lakes. We estimated a likely range in consumption of age-0 Yellow Perch using Smallmouth Bass diet information from two time periods when age-0 Yellow Perch constituted high (2008) and low (2012 and 2013) proportions of Smallmouth Bass diets, and bass population size estimates as inputs in a bioenergetics model. The proportion of age-0 Yellow Perch consumed by the Smallmouth Bass populations was determined by comparing estimates of consumption with estimates of age-0 perch production. During 2008, age-0 Yellow Perch constituted between 0% and 42% of Smallmouth Bass diets by weight, whereas during 2012 and 2013, age-0 perch constituted between 0% and 20% of bass diets by weight. Across both lakes and time periods, production of age-0 Yellow Perch ranged from 0.32 to 1.78 kg·ha−1·week−1. Estimates of Smallmouth Bass consumption measured during the same intervals ranged from 0.06 to 0.33 kg·ha−1·week−1, equating to consumption of between 1% and 34% of the available Yellow Perch biomass. Given current conditions relative to Smallmouth Bass abundance and consumption dynamics and production of age-0 Yellow Perch, it does not appear that Smallmouth Bass predation acts as a singular factor limiting recruitment of age-0 Yellow Perch in our study lakes. However, future research and management initiatives should recognize that the long-term impact of Smallmouth Bass predation is not static and will likely fluctuate depending on environmental (e.g., temperature) and biotic (e.g., trends in macrophyte abundance, predator and prey population structure and abundance, and predatory fish assemblage dynamics) characteristics.

Characterization and Extraction of Uranium Contamination Perched within the Deep Vadose Zone at the Hanford Site, Washington State

NASA Astrophysics Data System (ADS)

Williams, B. A.; Rohay, V. J.; Benecke, M. W.; Chronister, G. B.; Doornbos, M. H.; Morse, J.

2012-12-01

A highly contaminated perched water zone has been discovered in the deep vadose zone above the unconfined aquifer during drilling of wells to characterize groundwater contamination within the 200 East Area of the U.S. Department of Energy's Hanford Site in southeast Washington. The perched water, which contains nitrate, uranium, and technetium-99 at concentrations that have exceeded 100,000 μg/L, 70,000 μg/L, and 45,000 pCi/L respectively, is providing contamination to the underlying unconfined aquifer. A perched zone extraction well has been installed and is successfully recovering the contaminated perched water as an early remedial measure to reduce impacts to the unconfined aquifer. The integration and interpretation of various borehole hydrogeologic, geochemical, and geophysical data sets obtained during drilling facilitated the delineation of the perching horizon and determination of the nature and extent of the perched contamination. Integration of the borehole geologic and geophysical logs defined the structural elevation and thickness of the perching low permeability silt interval. Borehole geophysical moisture logs, gamma logs, and sample data allowed detailed determination of the elevation and thickness of the oversaturated zone above the perching horizon, and the extent and magnitude of the radiological uranium contamination within the perching interval. Together, these data sets resolved the nature of the perching horizon and the location and extent of the contaminated perched water within the perching zone, allowing an estimation of remaining contaminant extent. The resulting conceptual model indicates that the contaminated perched water is contained within a localized sand lens deposited in a structural low on top of a semi-regional low-permeability silt layer. The top of the sand lens is approximately 72 m (235 ft) below ground surface; the maximum thickness of the sand lens is approximately 3 m (10 ft). The lateral and vertical extent of the

Perching and takeoff of a robotic insect on overhangs using switchable electrostatic adhesion.

PubMed

Graule, M A; Chirarattananon, P; Fuller, S B; Jafferis, N T; Ma, K Y; Spenko, M; Kornbluh, R; Wood, R J

2016-05-20

For aerial robots, maintaining a high vantage point for an extended time is crucial in many applications. However, available on-board power and mechanical fatigue constrain their flight time, especially for smaller, battery-powered aircraft. Perching on elevated structures is a biologically inspired approach to overcome these limitations. Previous perching robots have required specific material properties for the landing sites, such as surface asperities for spines, or ferromagnetism. We describe a switchable electroadhesive that enables controlled perching and detachment on nearly any material while requiring approximately three orders of magnitude less power than required to sustain flight. These electroadhesives are designed, characterized, and used to demonstrate a flying robotic insect able to robustly perch on a wide range of materials, including glass, wood, and a natural leaf. Copyright © 2016, American Association for the Advancement of Science.

Effects of long-term changes in the benthic community on yellow perch in Saginaw Bay, Lake Huron

USGS Publications Warehouse

Schaeffer, Jeffrey S.; Diana, James S.; Haas, Robert C.

2000-01-01

Abundance, mortality, age and growth, food habits, and energetics of a yellow perch Perca flavescens population were investigated in eutrophic Saginaw Bay, Lake Huron during May to October, 1986 to 1988, and compared population characteristics with historical data from times when eutrophic conditions were less severe. During 1986 to 1988, yellow perch were abundant, but grew slowly and experienced high natural mortality. A size threshold was present at 150 to 180 mm beyond which few individuals survived, and sex ratios became biased toward males. An energetic model suggested that yellow perch were food limited; as they increased in size they spent a greater proportion of the growing season near maintenance ration. Low feeding rates were a consequence of subsistence on small chironomid larvae. Piscivory provided little energetic relief. Historical data suggested that availability of large benthic prey such as nymphs of the burrowing mayfly Hexagenia was important to yellow perch. Yellow perch formerly consumed Hexagenia, but mayflies were extirpated from Saginaw Bay during 1953 to 1965, and never recovered. When Hexagenia was present, yellow perch growth was moderate to fast depending on population size, size thresholds were not present, and yellow perch reached large size and older age despite moderate to high fishing mortality. Decreases in yellow perch growth rates during 1952 to 1955 coincided with extirpation of Hexagenia. Fast growth of yellow perch did occur after Hexagenia became extirpated, but only when fishing mortality was high, population size was small, and some large benthic invertebrates remained. Eutrophication of Saginaw Bay appeared to affect yellow perch by changing species composition and reducing size structure of the benthic community.

50 CFR 679.64 - Harvesting sideboard limits in other fisheries.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Pacific ocean perch. (A) The Aleutian Islands Pacific ocean perch harvest limit will be equal to the 1996 through 1997 aggregate retained catch of Aleutian Islands Pacific ocean perch by catcher/processors listed... sum of the Aleutian Islands Pacific ocean perch catch in 1996 and 1997 multiplied by the remainder of...

50 CFR 679.64 - Harvesting sideboard limits in other fisheries.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Pacific ocean perch. (A) The Aleutian Islands Pacific ocean perch harvest limit will be equal to the 1996 through 1997 aggregate retained catch of Aleutian Islands Pacific ocean perch by catcher/processors listed... sum of the Aleutian Islands Pacific ocean perch catch in 1996 and 1997 multiplied by the remainder of...

Age validation of canary rockfish (Sebastes pinniger) using two independent otolith techniques: lead-radium and bomb radiocarbon dating.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andrews, A H; Kerr, L A; Cailliet, G M

2007-11-04

Canary rockfish (Sebastes pinniger) have long been an important part of recreational and commercial rockfish fishing from southeast Alaska to southern California, but localized stock abundances have declined considerably. Based on age estimates from otoliths and other structures, lifespan estimates vary from about 20 years to over 80 years. For the purpose of monitoring stocks, age composition is routinely estimated by counting growth zones in otoliths; however, age estimation procedures and lifespan estimates remain largely unvalidated. Typical age validation techniques have limited application for canary rockfish because they are deep dwelling and may be long lived. In this study, themore » unaged otolith of the pair from fish aged at the Department of Fisheries and Oceans Canada was used in one of two age validation techniques: (1) lead-radium dating and (2) bomb radiocarbon ({sup 14}C) dating. Age estimate accuracy and the validity of age estimation procedures were validated based on the results from each technique. Lead-radium dating proved successful in determining a minimum estimate of lifespan was 53 years and provided support for age estimation procedures up to about 50-60 years. These findings were further supported by {Delta}{sup 14}C data, which indicated a minimum estimate of lifespan was 44 {+-} 3 years. Both techniques validate, to differing degrees, age estimation procedures and provide support for inferring that canary rockfish can live more than 80 years.« less

The effect of perch availability during pullet rearing and egg laying on the behavior of caged White Leghorn hens

USDA-ARS?s Scientific Manuscript database

Enriched cages, compared to conventional cages, allow egg laying strains of chickens to meet some behavioral needs, including the high motivation to perch. The objective of this study was to determine if perch availability during rearing affected perch use as adults and if perch presence affected ea...

Susceptibility of Australian Redfin Perch Perca fluviatilis Experimentally Challenged with Epizootic Hematopoietic Necrosis Virus (EHNV).

PubMed

Becker, Joy A; Tweedie, Alison; Gilligan, Dean; Asmus, Martin; Whittington, Richard J

2016-06-01

The ranavirus epizootic hematopoietic necrosis virus (EHNV) is endemic to Australia and is listed by the Office International des Epizooties. Clinical outbreaks have only been observed in wild populations of Redfin Perch Perca fluviatilis (also known as Eurasian Perch) and farmed populations of Rainbow Trout Oncorhynchus mykiss. The initial outbreaks of EHNV describe all age-classes of Redfin Perch as being susceptible and can lead to epidemic fish kills. Subsequently, experimental challenge studies using either cohabitation with the virus or injection exposures resulted in mixed susceptibilities across various age-groupings of Redfin Perch. We used an experimental bath challenge model to investigate the susceptibility of Redfin Perch collected from areas with and without a history of EHNV outbreaks. The median survival time for fish from Blowering Dam in New South Wales, a zone with a history of EHNV outbreaks, was 35 d, compared with fish from other areas, which had a median survival between 12 and 28 d postexposure. Redfin Perch from Blowering Dam demonstrated an increased mortality associated with epizootic hematopoietic necrosis up to approximately day 14 after exposure, and then there was a significantly reduced risk of mortality until the end of the trial compared with all other fish. Redfin Perch from Blowering Dam had markedly decreased susceptibility to EHNV, and less than 40% became infected following a bath challenge. In contrast, Redfin Perch from neighboring (e.g., Bethungra Dam and Tarcutta Creek) and distant water bodies (e.g., in Western Australia) with no previous history of EHNVdisplayed moderate to high susceptibility when given a bath challenge. Potential factors for the observed changes in the host-pathogen relationship include intense positive selection pressure for resistant fish following epizootic hematopoietic necrosis outbreaks and subsequent attenuation of the virulence of the virus in resistant fish. Received August 22, 2015; accepted

Histological observation of germ cell development and discovery of spermatophores in ovoviviparous black rockfish ( Sebastes schlegeli Hilgendorf) in reproductive season

NASA Astrophysics Data System (ADS)

Feng, Junrong; Liu, Liming; Jiang, Haibin; Wang, Maojian; Du, Rongbin

2014-10-01

Black rockfish ( Sebastes schlegeli) is an important species for culture; however, its reproductive characteristics have not been fully documented. In this study, we investigated the morphology and developmental process of germ cells in this ovoviviparous rockfish in reproductive season (October 2011-November 2012) with histological methods. We found that the gonad of mature fish showed notable seasonal changes in developmental characteristics and morphological structure. The sperm cells matured during a period lasting from October to December, significantly earlier than the oocytes did. A large number of spermatozoa and other cells occurred in testis at different developmental stages. Vitellogenesis in oocytes began in October, and gestation appeared in April next year. Spermatophores were discovered for the first time in Sebastes, which assembled in testis, main sperm duct, oviduct and genital tract, as well as ovarian cavity in October and April. These organs may serve either as production or hiding places for spermatophores and spermatozoa which were stored and transported in form of spermatophores. Testicular degeneration started from the distal part of testis in April, with spermatophores assembled in degenerating testis and waiting for transportation. The copulation probably lasted for a long period, during which the spermatozoa were discharged in batches as spermatophores. These spermatophores were coated with sticky materials secreted from the interstitial areas of testis and the main sperm duct, then transported into ovary.

The effect of perch availability during pullet rearing and egg laying on musculoskeletal health of caged White Leghorn hens.

PubMed

Hester, P Y; Enneking, S A; Haley, B K; Cheng, H W; Einstein, M E; Rubin, D A

2013-08-01

A major skeletal problem of conventionally caged hens is increased susceptibility to osteoporosis mainly due to lack of exercise. Osteoporosis is characterized by a progressive decrease in mineralized structural bone. Whereas considerable attention has been given to enriching laying cages, little research has been conducted on providing caged pullets with furnishments, in particular perches. The objective of the current study was to determine if metal perches during all or part of the life cycle of White Leghorns affected hen musculoskeletal health, especially at end of lay. Treatments during the pullet phase (hatch to 16.9 wk) entailed cages with and without perches. Four treatments were used during the laying phase (17 to 71 wk of age). Treatment 1 chickens never had access to perches at any point during their life cycle, typical of egg industry practices in the United States for conventional cages. Treatment 2 chickens had access to perches only during the egg-laying phase, which was from 17 to 71 wk of age. Treatment 3 chickens had access to perches only during the pullet phase (0 to 16.9 wk of age). Treatment 4 chickens had perch access throughout their entire life cycle (0 to 71 wk of age). Musculoskeletal health was assessed by measuring muscle weights, bone mineralization, bone fracture incidence, and keel bone deviations. Muscle deposition of 71-wk-old hens increased when given access to perches as pullets. Bone mineralization of 71-wk-old hens also increased if given perch access as adults. However, the disadvantage of the adult perch was the higher incidence of keel deviations and keel fractures at end of lay. The increase in bone mineralization of the keel bone as a result of perch access during the pullet and laying phases was not great enough to prevent a higher incidence of keel bone fractures at end of lay. Perch redesign and placement of perches within the cage to minimize keel fractures and deviations are possible solutions.

Morphological evidence for discrete stocks of yellow perch in Lake Erie

USGS Publications Warehouse

Kocovsky, Patrick M.; Knight, Carey T.

2012-01-01

Identification and management of unique stocks of exploited fish species are high-priority management goals in the Laurentian Great Lakes. We analyzed whole-body morphometrics of 1430 yellow perch Perca flavescens captured during 2007–2009 from seven known spawning areas in Lake Erie to determine if morphometrics vary among sites and management units to assist in identification of spawning stocks of this heavily exploited species. Truss-based morphometrics (n = 21 measurements) were analyzed using principal component analysis followed by ANOVA of the first three principal components to determine whether yellow perch from the several sampling sites varied morphometrically. Duncan's multiple range test was used to determine which sites differed from one another to test whether morphometrics varied at scales finer than management unit. Morphometrics varied significantly among sites and annually, but differences among sites were much greater. Sites within the same management unit typically differed significantly from one another, indicating morphometric variation at a scale finer than management unit. These results are largely congruent with recently-published studies on genetic variation of yellow perch from many of the same sampling sites. Thus, our results provide additional evidence that there are discrete stocks of yellow perch in Lake Erie and that management units likely comprise multiple stocks.

Assessing controls on perched saturated zones beneath the Idaho Nuclear Technology and Engineering Center, Idaho

USGS Publications Warehouse

Mirus, Benjamin B.; Perkins, Kim S.; Nimmo, John R.

2011-01-01

Waste byproducts associated with operations at the Idaho Nuclear Technology and Engineering Center (INTEC) have the potential to contaminate the eastern Snake River Plain (ESRP) aquifer. Recharge to the ESRP aquifer is controlled largely by the alternating stratigraphy of fractured volcanic rocks and sedimentary interbeds within the overlying vadose zone and by the availability of water at the surface. Beneath the INTEC facilities, localized zones of saturation perched on the sedimentary interbeds are of particular concern because they may facilitate accelerated transport of contaminants. The sources and timing of natural and anthropogenic recharge to the perched zones are poorly understood. Simple approaches for quantitative characterization of this complex, variably saturated flow system are needed to assess potential scenarios for contaminant transport under alternative remediation strategies. During 2009-2011, the U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, employed data analysis and numerical simulations with a recently developed model of preferential flow to evaluate the sources and quantity of recharge to the perched zones. Piezometer, tensiometer, temperature, precipitation, and stream-discharge data were analyzed, with particular focus on the possibility of contributions to the perched zones from snowmelt and flow in the neighboring Big Lost River (BLR). Analysis of the timing and magnitude of subsurface dynamics indicate that streamflow provides local recharge to the shallow, intermediate, and deep perched saturated zones within 150 m of the BLR; at greater distances from the BLR the influence of streamflow on recharge is unclear. Perched water-level dynamics in most wells analyzed are consistent with findings from previous geochemical analyses, which suggest that a combination of annual snowmelt and anthropogenic sources (for example, leaky pipes and drainage ditches) contribute to recharge of shallow and

Enzymatic correlates of energy status in wild yellow perch inhabiting clean and contaminated environments.

PubMed

Gauthier, Charles; Campbell, Peter G C; Couture, Patrice

2011-09-01

Enzymes representing a variety of metabolic pathways were examined in yellow perch (Perca flavescens) collected from a metal-contaminated region (Rouyn-Noranda, Québec, Canada) to determine which were most closely related to fish condition factor, pyloric caeca weight, and visceral lipid accumulation, as well to seek a better understanding of the influence of metal contamination on the physiology and biometrics of perch. Compared to laboratory fish, wild perch were under important energy restrictions. The condition factor of wild fish was correlated with indicators of aerobic metabolism (citrate synthase, cytochrome C oxidase), protein anabolism (nucleoside diphosphokinase), and indicators of lipid accumulation (glucose-6-phosphate dehydrogenase, visceral lipid index). Pyloric caeca weights were well correlated with indicators of protein anabolism, but only when both seasons were examined together, possibly indicating a lag in the response of enzymes to changes in diet. The addition of contaminant stress to existing energy restrictions led to changes in the relationships between enzymes and biometrics, reducing the predictive power of the models for perch in contaminated lakes. The present study broadens our knowledge of the impact of metal contamination on energy accumulation and tissue metabolic capacities in wild perch. Copyright © 2011 SETAC.

Production of monoclonal antibodies against serum immunoglobulins of black rockfish (Sebastes schlegeli Higendorf)

PubMed Central

Shin, Geewook; Lee, Hyungjun; Palaksha, K. J.; Kim, Youngrim; Lee, Eunyoung; Shin, Yongseung; Lee, Eunggoo; Park, Kyungdae

2006-01-01

The present study was undertaken to produce monoclonal antibodies (MAbs) against immunoglobulin (Ig) purified from black rockfish (Sebastes schlegeli Higendorf) serum using protein A, mannan binding protein, and goat IgG affinity columns. These three different ligands were found to possess high affinity for black rockfish serum Ig. All of the Igs purified eluted at only 0.46 M NaCl concentration in anion exchange column chromatography and consisted of two bands at 70 kDa and 25 kDa in SDS-PAGE; they also had similar antigenicity for MAbs to Ig heavy chain in immunoblot assays. Therefore, black rockfish Ig is believed to exist as a single isotype within serum. The MAbs produced against Ig heavy chain reacted specifically with spots distributed over the pI range from 4.8 to 5.6 with a molecular weight of 70 kDa on two dimensional gel electrophoresis immunoblot profiles. PMID:16871026

Night sampling improves indices used for management of yellow perch in Lake Erie

USGS Publications Warehouse

Kocovsky, P.M.; Stapanian, M.A.; Knight, C.T.

2010-01-01

Catch rate (catch per hour) was examined for age-0 and age-1 yellow perch, Perca flavescens (Mitchill), captured in bottom trawls from 1991 to 2005 in western Lake Erie: (1) to examine variation of catch rate among years, seasons, diel periods and their interactions; and (2) to determine whether sampling during particular diel periods improved the management value of CPH data used in models to project abundance of age-2 yellow perch. Catch rate varied with year, season and the diel period during which sampling was conducted as well as by the interaction between year and season. Indices of abundance of age-0 and age-1 yellow perch estimated from night samples typically produced better fitting models and lower estimates of age-2 abundance than those using morning or afternoon samples, whereas indices using afternoon samples typically produced less precise and higher estimates of abundance. The diel period during which sampling is conducted will not affect observed population trends but may affect estimates of abundance of age-0 and age-1 yellow perch, which in turn affect recommended allowable harvest. A field experiment throughout western Lake Erie is recommended to examine potential benefits of night sampling to management of yellow perch. Published 2010. The article is a US Government work and is in the public domain in the USA.

Mercury accumulation in yellow perch in Wisconsin seepage lakes: Relation to lake characteristics

USGS Publications Warehouse

Cope, W.G.; Wiener, J.G.; Rada, R.G.

1990-01-01

We studied relations between lacustrine characteristics and the total mercury (Hg) content of calendar age-2 yellow perch (Perca flavescens) in 10 seepage lakes in north-central Wisconsin. Mean concentrations and burdens (masses) of Hg in whole perch varied widely among lakes, were negatively correlated with lake pH and were positively correlated with total Hg concentration in surficial profundal sediment. Approximately 80 to 90% of the variation in Hg concentration and burden in whole perch was explained with multiple regressions containing two independent variables: either lake pH or alkalinity, and Hg concentration in surficial sediment. Variation among lakes in the Hg concentration in yellow perch was unrelated to their relative rates of growth. The mean concentration of Hg in axial muscle tissue of age-5 walleyes (Stizostedion vitreum vitreum) from five of the study lakes was highly correlated with the mean concentration in whole age-2 perch in the same lakes. We hypothesized that the high Hg concentrations often seen in piscivorous fish in low-alkalinity lakes (relative to high-alkalinity lakes) is at least partly due to a greater dietary intake of Hg in such waters. Furthermore, the analysis of small yellow perch—the preferred prey of adult walleyes and an important forage species for many predatory fishes in the north-central United States—may be an effective approach to assessing Hg bioavailability in the region's lakes.

Female reproductive impacts of dietary methylmercury in yellow perch (Perca flavescens) and zebrafish (Danio rerio).

PubMed

DeBofsky, Abigail R; Klingler, Rebekah H; Mora-Zamorano, Francisco X; Walz, Marcus; Shepherd, Brian; Larson, Jeremy K; Anderson, David; Yang, Luobin; Goetz, Frederick; Basu, Niladri; Head, Jessica; Tonellato, Peter; Armstrong, Brandon M; Murphy, Cheryl; Carvan, Michael J

2018-03-01

The purpose of this study was to evaluate the effects of environmentally relevant dietary MeHg exposures on adult female yellow perch (Perca flavescens) and female zebrafish (Danio rerio) ovarian development and reproduction. Yellow perch were used in the study for their socioeconomic and ecological importance within the Great Lakes basin, and the use of zebrafish allowed for a detailed analysis of the molecular effects of MeHg following a whole life-cycle exposure. Chronic whole life dietary exposure of F 1 zebrafish to MeHg mimics realistic wildlife exposure scenarios, and the twenty-week adult yellow perch exposure (where whole life-cycle exposures are difficult) captures early seasonal ovarian development. For both species, target dietary accumulation values were achieved prior to analyses. In zebrafish, several genes involved in reproductive processes were shown to be dysregulated by RNA-sequencing and quantitative real-time polymerase chain reaction (QPCR), but no significant phenotypic changes were observed regarding ovarian staging, fecundity, or embryo mortality. Yellow perch were exposed to dietary MeHg for 12, 16, or 20 weeks. In this species, a set of eight genes were assessed by QPCR in the pituitary, liver, and ovary, and no exposure-related changes were observed. The lack of genomic resources in yellow perch hinders the characterization of subtle molecular impacts. The ovarian somatic index, circulating estradiol and testosterone, and ovarian staging were not significantly altered by MeHg exposure in yellow perch. These results suggest that environmentally relevant MeHg exposures do not drastically reduce the reproductively important endpoints in these fish, but to capture realistic exposure scenarios, whole life-cycle yellow perch exposures are needed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of metal content in perch of the Ob River basin

NASA Astrophysics Data System (ADS)

Osipova, N. A.; Stepanova, K. D.; Matveenko, I. A.

2015-11-01

The geochemical features of river perch in the River Ob basin have been studied (the upper and middle reaches of the Ob River and the lower reach of the Tom River). The contents of Ag, Bi, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sn, W, Zn, Hg in perch's soft tissue are defined by the methods of ICP AES and stripping voltammetry, that of mercury in bones - by the atomic absorption method using mercury analyzer PA-915+. The distribution series of metal absolute concentrations in perch's soft tissue from the Ob River basin are plotted: Fe > Zn > Cu > Mn, typical for uncontaminated or slightly metal contaminated water bodies. In soft tissue of the studied samples the metal content does not exceed the permissible values. The mercury content in bones of studied samples is in the range 0,036-0,556 mg/kg. The mercury concentration is higher in bones in comparison with soft tissue in all samples.

Environmental heterogeneity associated with European perch (Perca fluviatilis) predation on invasive round goby (Neogobius melanostomus).

PubMed

Liversage, Kiran; Nurkse, Kristiina; Kotta, Jonne; Järv, Leili

2017-12-01

Spatiotemporal environmental variation affects fish feeding behaviour and capacity for piscivorous control of prey populations, which is important for management when prey include invasive species causing ecosystem impacts. We assessed gut-contents of an important piscivore (European perch Perca fluviatilis) over two years, and analysed variables affecting initiation and amounts of feeding, focusing on an important invasive prey species, round goby (Neogobius melanostomus). We show that predation is primarily controlled by variation of physical and habitat characteristics surrounding perch. Fish prey began being incorporated in diets of perch that were >150 mm, with temperature conditions controlling initiation of their feeding. Total amounts of fish in perch diets, and amounts of round goby individually, were strongly affected by macrophyte cover; seldom were fish present in perch stomachs when macrophyte cover was >40%. Environmental densities of round goby were related to multivariate diet composition in ways that suggest predation of some native species may be relaxed in areas of dense round goby populations. There was evidence that perch predation is unlikely to limit populations of the invader, as there was only a weak relationship between round goby densities and amounts in gut contents. The results have ecosystem management implications, because some variables found to be important could be manipulated to control round goby or other similar invaders e.g. fisheries management of native piscivore stock-density and body-size, or modification of benthic environment structure. Copyright © 2017 Elsevier Ltd. All rights reserved.

First Report of Clavinema mariae (Nematoda: Philometridae) in Cultured Rockfish, Sebastes schlegeli, in Cheonsuman (Bay), the Republic of Korea.

PubMed

Han, Hyun-Ja; Seo, Jung Soo; Park, Jeong Su; Lee, Haeng Lim; Seo, Han Gill; Jung, Sung Hee; Kwon, Se Ryun

2017-04-01

In July 2012, philometrid nematodes were discovered in cultured rockfish ( Sebastes schlegeli ) in Cheonsuman (Bay), the Republic of Korea. The nematodes were detected in the epithelial tissues of the rockfish and were identified as Clavinema mariae based on morphological studies using light and scanning electron microscopy. They revealed the characteristics same as previously identified C. mariae , notably having a long body with narrow posterior half, no caudal projection, a cylindrical-shaped esophagus, a well-developed anterior bulbous part of the esophagus, cephalic papillae, and a dorsal esophageal gland. This is the first confirmation of C. mariae infection in rockfish in Korea.

Increasing Mercury in Yellow Perch at a Hotspot in Atlantic Canada, Kejimkujik National Park

PubMed Central

2010-01-01

In the mid-1990s, yellow perch (Perca flavescens) and common loons (Gavia immer) from Kejimkujik National Park and National Historic Site (KNPNHS), Nova Scotia, Canada, had among the highest mercury (Hg) concentrations across North America. In 2006 and 2007, we re-examined 16 lakes to determine whether there have been changes in Hg in the loon’s preferred prey, yellow perch. Total Hg concentrations were measured in up to nine perch in each of three size classes (5−10 cm, 10−15 cm, and 15−20 cm) consumed by loons. Between 1996/97 and 2006/07, polynomial regressions indicated that Hg in yellow perch increased an average of 29% in ten lakes, decreased an average of 21% in three, and were unchanged in the remaining three lakes. In 2006/07, perch in 75% of the study lakes had Hg concentrations (standardized to 12-cm fish length) equal to or above the concentration (0.21 μg·g−1 ww) associated with a 50% reduction in maximum productivity of loons, compared with only 56% of these lakes in 1996/97. Mercury contamination currently poses a greater threat to loon health than a decade ago, and further reductions in anthropogenic emissions should be considered to reduce its impacts on ecosystem health. PMID:21062071

Effects of a mine tailings spill on feeding and metal concentrations in yellow perch (Perca flavescens)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Draves, J.F.; Fox, M.G.

1998-08-01

In this study, the authors examined the effects of a gold mine tailings spill in the Montreal River (northern Ontario, Canada) on juvenile yellow perch (Perca flavescens), a benthic-feeding fish, and identified the major contributors to their uptake of tailings metals (Pb, Zn, Cd, and Cu) in dietary items and river water. Juvenile perch sampled from a 6-km reach of the river where most of the tailings were deposited had significantly less food in their stomachs than individuals sampled from a reference reach of the river. Concentrations of Pb in invertebrate prey taxa from the contaminated reach were 9 tomore » 20 times higher than in those sampled from the reference reach. These differences were consistent with a higher concentration of Pb in perch from the contaminated reach. In contrast, Zn concentrations were high in river water and perch from both the reference and contaminated reaches, and little difference was found in Zn concentration between invertebrate prey types sampled from the two reaches. No significant differences were found in Cu or Cd concentrations in yellow perch sampled from the two reaches. Higher levels of Pb in the major prey types from the contaminated reach indicate that dietary uptake may be the major vector for Pb accumulation in yellow perch from the Montreal River.« less

Evidence of hypoxic foraging forays by yellow perch (Perca flavescens) and potential consequences for prey consumption

USGS Publications Warehouse

Roberts, James J.; Grecay, Paul A.; Ludsin, Stuart A.; Pothoven, Steve A.; Vanderploeg, Henry A.; Höök, Tomas O.

2012-01-01

Previous studies in a variety of ecosystems have shown that ecologically and economically important benthic and bentho-pelagic fishes avoid hypoxic (−1) habitats by moving vertically or horizontally to more oxygenated areas. While avoidance of hypoxic conditions generally leads to a complete shift away from preferred benthic prey, some individual fish continue to consume benthic prey items in spite of bottom hypoxia, suggesting complex habitat utilisation and foraging patterns. For example, Lake Erie yellow perch (Perca flavescens) continue to consume benthic prey, despite being displaced vertically and horizontally by hypolimnetic hypoxia. We hypothesised that hypolimnetic hypoxia can negatively affect yellow perch by altering their distribution and inducing energetically expensive foraging behaviour. To test this hypothesis, we used drifting hydroacoustics and trawl sampling to quantify water column distribution, sub-daily vertical movement and foraging behaviour of yellow perch within hypoxic and normoxic habitats of Lake Erie’s central basin during August-September 2007. We also investigated the effects of rapid changes in ambient oxygen conditions on yellow perch consumption potential by exposing yellow perch to various static and fluctuating oxygen conditions in a controlled laboratory experiment. Our results indicate that, while yellow perch in general avoid hypoxic conditions, some individuals undertake foraging forays into hypoxic habitats where they experience greater fluctuations in abiotic conditions (pressure, temperature and oxygen concentration) than at normoxic sites. However, laboratory results suggest short-term exposure to low oxygen conditions did not negatively impact consumption potential of yellow perch. Detailed understanding of sub-daily individual behaviours may be crucial for determining interactive individual- and ecosystem-level effects of stressors such as hypoxia.

The effect of perch access during pullet rearing and egg laying on physiological measurements of stress in 71-week-old White Leghorns

USDA-ARS?s Scientific Manuscript database

Egg laying strains of chickens have a strong motivation to perch. Providing caged chickens with perches allows them to perform their natural perching instinct and also improves their musculoskeletal health due to exercise. Little is known about the effect of perch access by hens on physiological mea...

The effect of perch access during pullet rearing and egg laying on physiological measures of stress in White Leghorns at 71 weeks of age.

PubMed

Yan, F F; Hester, P Y; Cheng, H W

2014-06-01

Egg laying strains of chickens have a strong motivation to perch. Providing caged chickens with perches allows them to perform their natural perching behavior and also improves their musculoskeletal health due to exercise. Little is known about the effect of perch access for hens on physiological measures of stress. Our hypothesis was that denying chickens access to perches would elicit a stress response. The objective of this study was to determine the effect of perch access during all or part of life cycle on physiological homeostasis in caged 71-wk-old White Leghorn hens. A total of 1,064 chicks were assigned randomly to cages with and without perches (n = 14 pullet cages/perch treatment) on day of hatch. As pullets aged, chicks were removed from cages to provide more space. At 17 wk of age, 324 chickens in total were assigned to laying cages consisting of 4 treatments with 9 replicates per treatment. Treatment 1 chickens never had access to perches during their life cycle. Treatment 2 chickens had access to perches only from 17 to 71 wk of age (laying phase). Treatment 3 chickens had access to perches only from hatch to 16.9 wk of age (pullet phase). Treatment 4 chickens always had access to perches during their life cycle. At 71 wk of age, chickens were sampled for measurement of plasma catecholamines (epinephrine, norepinephrine, and dopamine) and corticosterone; blood serotonin and Trp; fluctuating asymmetry of shank length and width; and adrenal weight. Only shank width differed among treatments. Chickens with previous exposure to perches during the pullet phase had wider shanks than chickens without access to perches (P = 0.006), suggesting that early perching promoted skeletal development. These results suggest that a stress response was not elicited in 71-wk-old White Leghorn hens that always had access to perches compared with hens that never had access to perches during all or part of their life cycle. Poultry Science Association Inc.

Cormorant predation and the population dynamics of walleye and yellow perch in Oneida Lake

USGS Publications Warehouse

Rudstam, L. G.; VanDeValk, A.J.; Adams, C.M.; Coleman, J.T.H.; Forney, J.L.; Richmond, M.E.

2004-01-01

Double-crested Cormorants (Phalacrocorax auritus) increased dramatically in North America during the 1990s, providing the opportunity to study the effects of an increase of a top predator on an existing predator-prey system. In Oneida Lake, New York, USA, Double-crested Cormorants were first observed nesting in 1984 and had increased to over 360 nesting pairs by 2000. Concomitant with this increase in piscivorous birds was a decrease in the adult walleye (Stizostedion vitreum) and yellow perch (Perca flavescens) populations. Analysis of a 40-yr data series shows higher mortality of subadults (age 1-2 yr perch and age 1-3 yr walleye) for both species in the 1990s compared to the previous three decades. Cormorant diet was investigated from 1995 to 2000 using a combination of cast pellets, regurgitants, and stomach analysis. Walleye and yellow perch were a major portion of the cormorant diet during these years (40-82% by number). The number of subadult walleye and yellow perch consumed by cormorants suggests that the increase in subadult mortality can be explained by predation from cormorants. Mean mortality rates of adult percids attributed to cormorant predation were 1.1% per year for walleye and 7.7% per year for yellow perch. Our analysis suggests that predation by cormorants on subadult percids is a major factor contributing to the decline in both the walleye and the yellow perch populations in Oneida Lake. Other ecosystem changes (zebra mussels, lower nutrient loading, decrease in alternate prey) are not likely explanations because the potential mechanisms involved are not consistent with auxiliary data from the lake and would not affect subadult mortality. The likely impact of bird predation on percid populations in Oneida Lake occurs because cormorants feed on larger fish that are beyond the size range where compensatory mechanisms are important.

Modeling turbidity type and intensity effects on the growth and starvation mortality of age-0 yellow perch

USGS Publications Warehouse

Manning, Nathan M; Bossenbroek, Jonathan M.; Mayer, Christine M.; Bunnell, David B.; Tyson, Jeff T.; Rudstam, Lars G.; Jackson, James R.

2014-01-01

We sought to quantify the possible population-level influence of sediment plumes and algal blooms on yellow perch (Perca flavescens), a visual predator found in systems with dynamic water clarity. We used an individual-based model (IBM), which allowed us to include variance in water clarity and the distribution of individual sizes. Our IBM was built with laboratory data showing that larval yellow perch feeding rates increased slightly as sediment turbidity level increased, but that both larval and juvenile yellow perch feeding rates decreased as phytoplankton level increased. Our IBM explained a majority of the variance in yellow perch length in data from the western and central basins of Lake Erie and Oneida Lake, with R2 values ranging from 0.611 to 0.742. Starvation mortality was size dependent, as the greatest daily mortality rates in each simulation occurred within days of each other. Our model showed that turbidity-dependent consumption rates and temperature are key components in determining growth and starvation mortality of age-0 yellow perch, linking fish production to land-based processes that influence water clarity. These results suggest the timing and persistence of sediment plumes and algal blooms can drastically alter the growth potential and starvation mortality of a yellow perch cohort.

Response of walleye and yellow perch to water-level fluctuations in glacial lakes

USGS Publications Warehouse

Dembkowski, D.J.; Chipps, Steven R.; Blackwell, B. G.

2014-01-01

The influence of water levels on population characteristics of yellow perch, Perca flavescens (Mitchill), and walleye, Sander vitreus (Mitchill), was evaluated across a range of glacial lakes in north-eastern South Dakota, USA. Results showed that natural variation in water levels had an important influence on frequently measured fish population characteristics. Yellow perch abundance was significantly (P<0.10) greater during elevated water levels. Yellow perch size structure, as indexed by the proportional size distribution of quality- and preferred-length fish (PSD and PSD-P), was significantly greater during low-water years, as was walleye PSD. Mean relative weight of walleye increased significantly during high-water periods. The dynamic and unpredictable nature of water-level fluctuations in glacial lakes ultimately adds complexity to management of these systems.

Effects of the filamentous cyanobacterium Nodularia on fitness and feeding behavior of young-of-the-year (YOY) Eurasian perch (Perca fluviatilis).

PubMed

Persson, Karl-Johan; Stenroth, Patrik; Legrand, Catherine

2011-06-01

This study reveals that both cyanobacterial toxicity and turbidity have the potential to reduce the growth and energy storage of young-of-the-year (YOY) perch and thereby influence survival rates. During the 1990's a reduction in recruitment of YOY perch (Perca fluviatilis) occurred along the Swedish East coast. Concurrently, large blooms of filamentous cyanobacteria have increased in the Baltic Proper and in coastal waters. This study examined whether extended exposure to toxic and non-toxic filamentous cyanobacterium Nodularia affect YOY perch growth and feeding behavior under simulated bloom conditions (30 days at 50 μg Chl a L(-1)). Specific growth rate (SGR), the somatic condition index (SCI) and the lipid content of YOY perch (10-12 weeks old) were significantly lower in perch exposed to Nodularia compared to fed controls (no Nodularia). YOY perch exposed to non-toxic Nodularia displayed a higher attack rate than perch living in Nodularia free controls in 2 out of 3 trials. Reductions in growth and energy storage, mediated by cyanobacteria, increase the risk of starvation and predation and could locally influence recruitment of YOY perch. Copyright © 2011 Elsevier Ltd. All rights reserved.

Female reproductive impacts of dietary methylmercury in yellow perch (Perca flavescens) and zebrafish (Danio rerio)

USDA-ARS?s Scientific Manuscript database

The purpose of this study was to evaluate the effects of environmentally relevant dietary MeHg exposures on adult female yellow perch (Perca flavescens) and zebrafish (Danio rerio)reproduction. Yellow perch were used in the study for their socioeconomic and ecological importance within the Great Lak...

Boldness in two perch populations - long-term differences and the effect of predation pressure.

PubMed

Magnhagen, Carin; Hellström, Gustav; Borcherding, Jost; Heynen, Martina

2012-11-01

1. Populations of the same species often display different behaviours, for example, in their response to predators. The question is whether this difference is developed as part of a divergent selection caused by differences in predation pressure, or as a result of phenotypic responses to current environmental conditions. 2. Two populations of Eurasian perch were investigated over a time span of 6 years to see whether risk-taking behaviour in young-of-the-year perch were consistent across cohorts, or if behaviour varied over time with changes in predation regime. 3. Boldness was estimated in aquarium studies by looking at how the fish made trade-offs between foraging in a risky area and staying in shelter. Predation risk of each year and lake was estimated from fishing surveys, using an individual-based model calculating attack rates for cannibalistic perch. 4. The average boldness scores were consistently lower in perch from Fisksjön compared with those in Ängersjön, although the magnitude of the difference varied among years. Variance component analyses showed that differences between lakes in boldness scores only explained 12 per cent of the total variation. Differences between years were contributing at least similarly or more to the total variance, and the variation was higher in Fisksjön than in Ängersjön. 5. The observed risk-taking behaviour of young-of-the-year perch, compared across cohorts, was significantly correlated with the year-specific estimates of cannibalistic attack rates, with lower boldness scores in years with higher predation pressure. In Fisksjön, with significant changes over the years in population structure, the range of both predation risk and boldness scores was wider than in Ängersjön. 6. By following the two perch populations over several years, we have been able to show that the differences in risk-taking behaviour mainly are due to direct phenotypic responses to recent experience of predation risk. Long-term differences in

Precision of four otolith techniques for estimating age of white perch from a thermally altered reservoir

USGS Publications Warehouse

Snow, Richard A.; Porta, Michael J.; Long, James M.

2018-01-01

The White Perch Morone americana is an invasive species in many Midwestern states and is widely distributed in reservoir systems, yet little is known about the species' age structure and population dynamics. White Perch were first observed in Sooner Reservoir, a thermally altered cooling reservoir in Oklahoma, by the Oklahoma Department of Wildlife Conservation in 2006. It is unknown how thermally altered systems like Sooner Reservoir may affect the precision of White Perch age estimates. Previous studies have found that age structures from Largemouth Bass Micropterus salmoides and Bluegills Lepomis macrochirus from thermally altered reservoirs had false annuli, which increased error when estimating ages. Our objective was to quantify the precision of White Perch age estimates using four sagittal otolith preparation techniques (whole, broken, browned, and stained). Because Sooner Reservoir is thermally altered, we also wanted to identify the best month to collect a White Perch age sample based on aging precision. Ages of 569 White Perch (20–308 mm TL) were estimated using the four techniques. Age estimates from broken, stained, and browned otoliths ranged from 0 to 8 years; whole‐view otolith age estimates ranged from 0 to 7 years. The lowest mean coefficient of variation (CV) was obtained using broken otoliths, whereas the highest CV was observed using browned otoliths. July was the most precise month (lowest mean CV) for estimating age of White Perch, whereas April was the least precise month (highest mean CV). These results underscore the importance of knowing the best method to prepare otoliths for achieving the most precise age estimates and the best time of year to obtain those samples, as these factors may affect other estimates of population dynamics.

Using Sulfur Stable Isotopes to Understand Feeding Behavior and Selenium Concentrations in Yellow Perch (Perca flavescens).

PubMed

Ponton, Dominic E; Hare, Landis

2015-07-07

We measured selenium (Se) concentrations in yellow perch (Perca flavescens) muscle and their prey collected from four Se-contaminated lakes located near metal smelters in the eastern Canadian cities of Sudbury and Rouyn-Noranda. Yellow perch Se concentrations were related to their weight in two of the four lakes. Measurements of sulfur stable isotopes (δ(34)S) in yellow perch muscle and stomach contents showed that larger fish tended to feed less on zooplankton and more on benthic invertebrates than did smaller fish. Because Se concentrations are lower and δ(34)S signatures are higher in zooplankton than in sediment-feeding invertebrates, there was an inverse relationship between animal Se concentrations and δ(34)S signatures in all of our study lakes. δ(34)S signatures were highly effective in characterizing these food web relationships. Selenium concentrations in yellow perch were 1.6 times those of its prey, which indicates that Se is biomagnified by this fish in our study lakes. Estimated Se concentrations in yellow perch gonads suggest that in two of our study lakes one-third of fish are at risk of reproductive toxicity.

The Effect of Cooled Perches on Immunological Parameters of Caged White Leghorn Hens during the Hot Summer Months

PubMed Central

Strong, Rebecca A.; Hester, Patricia Y.; Eicher, Susan D.; Hu, Jiaying; Cheng, Heng-Wei

2015-01-01

The objective of this study was to determine if thermally cooled perches improve hen immunity during hot summer. White Leghorn pullets at 16 week of age were randomly assigned to 18 cages of 3 banks at 9 hens per cage. Each bank was assigned to 1 of the 3 treatments up to 32 week of age: 1) thermally cooled perches, 2) perches with ambient air, and 3) cages without perches. Hens were exposed to natural ambient temperatures from June through September 2013 in Indiana with a 4 h acute heat episode at 27.6 week of age. The packed cell volume, heterophil to lymphocyte (H/L) ratio, plasma concentrations of total IgG, and cytokines of interleukin-1β and interleukin-6, plus lipopolysaccharide-induced tumor necrosis factor-α factor were measured at both 27.6 and 32 week of age. The mRNA expressions of these cytokines, toll-like receptor-4, and inducible nitric oxide synthase were also examined in the spleen of 32 week-old hens. Except for H/L ratio, thermally cooled perches did not significantly improve currently measured immunological indicators. These results indicated that the ambient temperature of 2013 summer in Indiana (24°C, 17.1 to 33.1°C) was not high enough and the 4 h heat episode at 33.3°C (32 to 34.6°C) was insufficient in length to evoke severe heat stress in hens. However, cooled perch hens had a lower H/L ratio than both air perch hens and control hens at 27.6 week of age and it was still lower compared to control hens (P < 0.05, respectively) at 32 week of age. The lowered H/L ratio of cooled perch hens may suggest that they were able to cope with acute heat stress more effectively than control hens. Further studies are needed to evaluate the effectiveness of thermally cooled perches on hen health under higher ambient temperatures. PMID:26495988

A microsatellite genetic linkage map of black rockfish ( Sebastes schlegeli)

NASA Astrophysics Data System (ADS)

Chu, Guannan; Jiang, Liming; He, Yan; Yu, Haiyang; Wang, Zhigang; Jiang, Haibin; Zhang, Quanqi

2014-12-01

Ovoviviparous black rockfish ( Sebastes schlegeli) is an important marine fish species for aquaculture and fisheries in China. Genetic information of this species is scarce because of the lack of microsatellite markers. In this study, a large number of microsatellite markers of black rockfish were isolated by constructing microsatellite-enriched libraries. Female- and male-specific genetic linkage maps were constructed using 435 microsatellite markers genotyped in a full-sib family of the fish species. The female linkage map contained 140 microsatellite markers, in which 23 linkage groups had a total genetic length of 1334.1 cM and average inter-marker space of 13.3 cM. The male linkage map contained 156 microsatellite markers, in which 25 linkage groups had a total genetic length of 1359.6 cM and average inter-marker distance of 12.4 cM. The genome coverage of the female and male linkage maps was 68.6% and 69.3%, respectively. The female-to-male ratio of the recombination rate was approximately 1.07:1 in adjacent microsatellite markers. This paper presents the first genetic linkage map of microsatellites in black rockfish. The collection of polymorphic markers and sex-specific linkage maps of black rockfish could be useful for further investigations on parental assignment, population genetics, quantitative trait loci mapping, and marker-assisted selection in related breeding programs.

Scaling the sublethal effects of methylmercury to yellow perchs population dynamics using adverse outcome pathway framework

USDA-ARS?s Scientific Manuscript database

This study sought to evaluate the effects of environmentally relevant dietary MeHg exposures on adult female yellow perch (Perca flavescens) and zebrafish (Danio rerio) reproduction. Yellow perch were used in the study for their socioeconomic and ecological importance within the Great Lakes basin, a...

50 CFR 679.64 - Harvesting sideboard limits in other fisheries.

Code of Federal Regulations, 2014 CFR

2014-10-01

... area or subarea of the BSAI as follows: (i) Aleutian Islands Pacific ocean perch. (A) The Aleutian Islands Pacific ocean perch harvest limit will be equal to the 1996 through 1997 aggregate retained catch of Aleutian Islands Pacific ocean perch by catcher/processors listed in Sections 208(e)(1) through...

Co-infections of infectious spleen and kidney necrosis virus and Siniperca chuatsi rhabdovirus in Chinese perch (Siniperca chuatsi).

PubMed

Lin, Qiang; Fu, Xiaozhe; Li, Ningqiu; Wan, Quanyuan; Chen, Wenjie; Huang, Yunmao; Huang, Zhibin; Li, Jun; Zhao, Lijuan; Lin, Li

2017-10-01

In spite of the quite common co-infections of viruses in the cultured fish, most of the previous studies have just simply focused on the infection of a single pathogen. In this report, we observed that about 13% of cultured Chinese perch have been co-infected by infectious spleen and kidney necrosis virus (ISKNV) and Siniperca chuatsi rhabdovirus (SCRV). Furthermore, Chinese perch could co-infected by ISKNV and SCRV by intraperitoneally injection with the two viruses. Interestingly, we revealed that the two viruses could even co-infect a single cell of Chinese perch in vivo and a single Chinese perch brain cells (CPB) cell in vitro. The dynamic co-infected viruses loads in the different tissues of Chinese perch showed dependent. When CPB cells were infected with the same 10 MOI of SCRV and ISKNV, the replication of SCRV overwhelmed the replication of ISKNV. When the MOI of ISKNV (10 MOI) was 10,000 times of MOI of SCRV (0.001 MOI), the dynamic virus loads of the two viruses in CPB cells indicated that co-infections could synergistically stimulate both viruses replication at the late time points but not at early time points. The co-infections of ISKNV and SCRV in the cultured Chinese perch will shed a new light on the prevention of the viral diseases of Chinese perch. The development of multivalent vaccine which could be effective for preventing against the co-infections of the viruses is highly needed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Identifying across‐system sources of variation in a generalist freshwater fish: Correlates of total and size‐specific abundance of yellow perch

USGS Publications Warehouse

Carey, Michael P.; Mather, M. E.

2009-01-01

Variation in fish abundance across systems presents a challenge to our understanding of fish populations because it limits our ability to predict and transfer basic ecological principles to applied problems. Yellow perch (Perca flavescens) is an ideal species for exploring environmental and biotic correlates across system because it is widely distributed and physiologically tolerant. In 16 small, adjacent systems that span a wide range of environmental and biotic conditions, yellow perch were sampled with a standard suite of gear. Water quality, morphometry, vegetation, invertebrates and fish communities were concurrently measured. Multimodel inference was used to prioritise regressors for the entire yellow perch sample and three size groups (35-80, 81-180, ≥181 mm TL). Across systems, pH and fish richness were identified as the key drivers of yellow perch abundance. At very low pH (<4.0), few fish species and few yellow perch individuals were found. At ponds with moderately low pH (4.0–4.8), numbers of yellow perch increased. Ponds with high pH (>4.8) had many other species and few yellow perch. Similar patterns for pH and fish community were observed for the two largest‐size classes. Negative interactions were observed between the medium‐ and large‐sized yellow perch and between the largest and smallest yellow perch, although interspecific interactions were weaker than expected. This examination of variability for an indicator species and its component‐size classes provides ecological understanding that can help frame the larger‐scale sampling programs needed for the conservation of freshwater fish.

Does boldness explain vulnerability to angling in Eurasian perch Perca fluviatilis?

PubMed

Vainikka, Anssi; Tammela, Ilkka; Hyvärinen, Pekka

2016-04-01

Consistent individual differences (CIDs) in behavior are of interest to both basic and applied research, because any selection acting on them could induce evolution of animal behavior. It has been suggested that CIDs in the behavior of fish might explain individual differences in vulnerability to fishing. If so, fishing could impose selection on fish behavior. In this study, we assessed boldness-indicating behaviors of Eurasian perch Perca fluviatilis using individually conducted experiments measuring the time taken to explore a novel arena containing predator (burbot, Lota lota ) cues. We studied if individual differences in boldness would explain vulnerability of individually tagged perch to experimental angling in outdoor ponds, or if fishing would impose selection on boldness-indicating behavior. Perch expressed repeatable individual differences in boldness-indicating behavior but the individual boldness-score (the first principal component) obtained using principal component analysis combining all the measured behavioral responses did not explain vulnerability to experimental angling. Instead, large body size appeared as the only statistically significant predictor of capture probability. Our results suggest that angling is selective for large size, but not always selective for high boldness.

Does boldness explain vulnerability to angling in Eurasian perch Perca fluviatilis?

PubMed Central

Vainikka, Anssi; Tammela, Ilkka; Hyvärinen, Pekka

2016-01-01

Abstract Consistent individual differences (CIDs) in behavior are of interest to both basic and applied research, because any selection acting on them could induce evolution of animal behavior. It has been suggested that CIDs in the behavior of fish might explain individual differences in vulnerability to fishing. If so, fishing could impose selection on fish behavior. In this study, we assessed boldness-indicating behaviors of Eurasian perch Perca fluviatilis using individually conducted experiments measuring the time taken to explore a novel arena containing predator (burbot, Lota lota) cues. We studied if individual differences in boldness would explain vulnerability of individually tagged perch to experimental angling in outdoor ponds, or if fishing would impose selection on boldness-indicating behavior. Perch expressed repeatable individual differences in boldness-indicating behavior but the individual boldness-score (the first principal component) obtained using principal component analysis combining all the measured behavioral responses did not explain vulnerability to experimental angling. Instead, large body size appeared as the only statistically significant predictor of capture probability. Our results suggest that angling is selective for large size, but not always selective for high boldness. PMID:29491897

Rapid area change in pitch-up manoeuvres of small perching birds.

PubMed

Polet, D T; Rival, D E

2015-10-26

Rapid pitch-up has been highlighted as a mechanism to generate large lift and drag during landing manoeuvres. However, pitching rates had not been measured previously in perching birds, and so the direct applicability of computations and experiments to observed behaviour was not known. We measure pitch rates in a small, wild bird (the black-capped chickadee; Poecile atricapillus), and show that these rates are within the parameter range used in experiments. Pitching rates were characterized by the shape change number, a metric comparing the rate of frontal area increase to acceleration. Black-capped chickadees increase the shape change number during perching in direct proportion to their total kinetic and potential energy at the start of the manoeuvre. The linear relationship between dissipated energy and shape change number is in accordance with a simple analytical model developed for two-dimensional pitching and decelerating airfoils. Black-capped chickadees use a wing pitch-up manoeuvre during perching to dissipate energy quickly while maintaining lift and drag through rapid area change. It is suggested that similar pitch-and-decelerate manoeuvres could be used to aid in the controlled, precise landings of small manoeuvrable air vehicles.

Robust post-stall perching with a simple fixed-wing glider using LQR-Trees.

PubMed

Moore, Joseph; Cory, Rick; Tedrake, Russ

2014-06-01

Birds routinely execute post-stall maneuvers with a speed and precision far beyond the capabilities of our best aircraft control systems. One remarkable example is a bird exploiting post-stall pressure drag in order to rapidly decelerate to land on a perch. Stall is typically associated with a loss of control authority, and it is tempting to attribute this agility of birds to the intricate morphology of the wings and tail, to their precision sensing apparatus, or their ability to perform thrust vectoring. Here we ask whether an extremely simple fixed-wing glider (no propeller) with only a single actuator in the tail is capable of landing precisely on a perch from a large range of initial conditions. To answer this question, we focus on the design of the flight control system; building upon previous work which used linear feedback control design based on quadratic regulators (LQR), we develop nonlinear feedback control based on nonlinear model-predictive control and 'LQR-Trees'. Through simulation using a flat-plate model of the glider, we find that both nonlinear methods are capable of achieving an accurate bird-like perching maneuver from a large range of initial conditions; the 'LQR-Trees' algorithm is particularly useful due to its low computational burden at runtime and its inherent performance guarantees. With this in mind, we then implement the 'LQR-Trees' algorithm on real hardware and demonstrate a 95 percent perching success rate over 147 flights for a wide range of initial speeds. These results suggest that, at least in the absence of significant disturbances like wind gusts, complex wing morphology and sensing are not strictly required to achieve accurate and robust perching even in the post-stall flow regime.

Thirty-Year-Old Paradigm about Unpalatable Perch Egg Strands Disclaimed by the Freshwater Top-Predator, the European Catfish (Silurus glanis)

PubMed Central

Kočvara, Luboš; Sajdlová, Zuzana; Hoang The, Son Chung; Šmejkal, Marek; Peterka, Jiří

2017-01-01

So far, perch egg strands have been considered unpalatable biological material. However, we repeatedly found egg strands of European perch (Perca fluviatilis) in the diet of European catfish (Silurus glanis) caught by longlines in Milada and Most Lakes, Czech Republic. The finding proves that perch egg strands compose a standard food source for this large freshwater predatory fish. It extends the present knowledge on catfish foraging plasticity, showing it as an even more opportunistic feeder. Utilization of perch egg strands broadens the catfish diet niche width and represents an advantage against other fish predators. Comparison of datasets from extensive gillnet and SCUBA diver sampling campaigns gave the evidence that at least in localities where food sources are limited, multilevel predation by catfish may have an important impact on the perch population. PMID:28060862

Effects of clay turbidity and density of pikeperch (Sander lucioperca) larvae on predation by perch (Perca fluviatilis).

PubMed

Pekcan-Hekim, Zeynep; Lappalainen, Jyrki

2006-07-01

Increased turbidity reduces visibility in the water column, which can negatively affect vision-oriented fish and their ability to detect prey. Young fish could consequently benefit from high turbidity levels that can provide a protective cover, reducing predation pressure. Perch (Perca fluviatilis) are commonly found in littoral zones of temperate lakes and coastal areas of the Baltic Sea. Pikeperch (Sander lucioperca) spawn in these areas, so perch is a potential predator for pikeperch larvae. We conducted laboratory experiments to test the predation of perch on pikeperch larvae at different turbidity levels (5-85 nephelometric turbidity units), densities of pikeperch larvae (2-21 individuals l(-1)) and volumes of water (10-45 l). The logistic regression showed that the probability of larvae eaten depended significantly on turbidity and volume of water in the bags, while density of larvae was not significant. However, because container size is known to affect predation, the data was divided into two groups based on water volume (10-20 and 25-45 l) to reduce the effects of container size. In either group, probability of predation did not significantly depend on volume, whereas turbidity was significant in both groups, while density was significant in larger water volumes. Thus, high turbidity impaired perch predation and protected pikeperch larvae from perch predation. Because density of larvae was also a significant factor affecting predation of perch, the dispersal of pikeperch larvae from spawning areas should also increase the survival of larvae.

Establishment and characterization of a brain cell line from sea perch, Lateolabrax japonicus.

PubMed

Le, Yao; Li, Yunlong; Jin, Yilin; Jia, Peng; Jia, Kuntong; Yi, Meisheng

2017-10-01

A continuous cell line, designated LJB, derived from the brain of sea perch (Lateolabrax japonicus) was established. LJB cells have been subcultured for more than 60 times in Dulbecco's modified Eagle's medium (DMEM) supplemented with 15% fetal bovine serum (FBS) since the initial primary culture. LJB cells exhibited maximum growth rate at 28°C in DMEM supplemented with 20% FBS. Cytogenetic analysis indicated that the modal chromosome number was 48, which was identical with the chromosome number of embryonic stem-like cells of sea perch. Comparison of the 18S ribosomal RNA gene sequences of LJB cells and sea perch confirmed that LJB cells originated from sea perch. After transfected with pEGFP-N3 plasmid, LJB cells showed a transfection efficiency of about 40% which was indicated by the percentage of cells expressing green fluorescence protein, indicating the potential application of LJB cells in gene expression studies. Cytopathic effect was clearly observed, and RNA-dependent RNA polymerase gene was also detected in LJB cells post red-spotted grouper nervous necrosis virus (RGNNV) infection. Furthermore, virus replication was confirmed by quantitative RT-PCR, virus titer, and transmission electron microscopy assay in RGNNV-infected LJB cells. The LJB cell line might be used as an ideal in vitro tool for analyzing and understanding the mechanisms of nervous necrosis virus-host interaction.

The Effects of Zebra Mussels (Dreissena polymorpha) on the Foraging Success of Eurasian Perch (Perca fluviatilis) and Ruffe (Gymnocephalus cernuus)

NASA Astrophysics Data System (ADS)

Dieterich, Axel; Mörtl, Martin; Eckmann, Reiner

2004-07-01

Complex habitat structures can influence the foraging success of fish. Competition for food between fish species can therefore depend on the competitors' abilities to cope with structural complexity. In laboratory experiments, we comparatively assessed effects of zebra mussels (Dreissena polymorpha Pall.) on the foraging success of Eurasian perch (Perca fluviatilis L.) and ruffe (Gymnocephalus cernuus (L.)). In single-species and mixed-species experiments, the fish were fed caddisfly larvae (Tinodes waeneri (L.)) over complex (mussel-covered stones) and less-complex (bare stones) substrates. With intraspecific competition, food consumption by perch and ruffe decreased significantly when the complex substrate was used. With interspecific competition, food consumption by perch and ruffe did not change with substrate complexity, but perch clearly out-competed ruffe on both substrates. Zebra mussel beds provide a refuge for macrozoobenthos against predation by ruffe and probably also by perch. (

Comparative effects of constant versus fluctuating thermal regimens on yellow perch growth, feed conversion and survival

USDA-ARS?s Scientific Manuscript database

The effects of fluctuating or constant thermal regimens on growth, mortality, and feed conversion were determined for juvenile yellow perch (Perca flavescens). Yellow perch averaging 156mm total length and 43g body weight were held in replicate 288L circular tanks for 129 days under: 1) a diel therm...

Priority effects among young‐of‐the‐year fish: reduced growth of bluegill sunfish (Lepomis macrochirus) caused by yellow perch (Perca flavescens)?

USGS Publications Warehouse

Kaemingk, Mark A.; Jolley, Jeff C.; Willis, David W.; Chipps, Steven R.

2012-01-01

1. When available, Daphnia spp. are often preferred by age-0 yellow perch and bluegill sunfish because of energetic profitability. We hypothesised that predation by age-0 yellow perch could lead to a midsummer decline (MSD) of Daphnia spp. and that priority effects may favour yellow perch because they hatch before bluegill, allowing them to capitalise on Daphnia spp. prior to bluegill emergence.2. Data were collected from 2004 to 2010 in Pelican Lake, Nebraska, U.S.A. The lake experienced a prolonged MSD in all but 1 year (2005), generally occurring within the first 2 weeks of June except in 2008 and 2010 when it occurred at the end of June. MSD timing is not solely related to seasonal patterns of age-0 yellow perch consumption. Nevertheless, when Daphnia spp. biomass was low during 2004 and 2006–2010 (<4 mg wet weight L−1), predation by age-0 yellow perch seems to have suppressed Daphnia spp. biomass (i.e. <1.0 mg wet weight L−1). The exception was 2005 when age-0 yellow perch were absent.3. Growth of age-0 bluegill was significantly faster in 2005, when Daphnia spp. were available in greater densities (>4 mg wet weight L−1) compared with the other years (<0.2 mg wet weight L−1).4. We conclude that age-0 yellow perch are capable of reducing Daphnia biomass prior to the arrival of age-0 bluegill, ultimately slowing bluegill growth. Thus, priority effects favour age-0 yellow perch when competing with age-0 bluegill for Daphnia. However, these effects may be minimised if there is a shorter time between hatching of the two species, higher Daphnia spp. densities or lower age-0 yellow perch densities.

Effect of Feeding-Fasting Cycles on Oxygen Consumption and Bioenergetics of Yellow Perch

USGS Publications Warehouse

Chipps, Steven R.; Travis W. Schaeffer,; Daniel E. Spengler,; Casey W. Schoenebeck,; Michael L. Brown,

2012-01-01

We measured growth and oxygen consumption of age-1 yellow perch Perca flavescenssubjected to ad libitum (control) or variable feeding cycles of 2 (i.e., 2 d of feed, 2 d of deprivation), 6, or 12 d for a 72-d period. Individual, female yellow perch (initial weight = 51.9 ± 0.9 g [mean ± SE]) were stocked in 110-L aquaria to provide six replicates per treatment and fed measured rations of live fathead minnow Pimephales promelas. Consumption, absolute growth rate, growth efficiency, and oxygen consumption were similar among feeding regimens. However, growth trajectories for fish on the 2-d cycle were significantly lower than other feed–fast cycles. Hyperphagia occurred in all treatments. Bioenergetics model simulations indicated that consumption was significantly underestimated (t = 5.4, df = 4, P = 0.006), while growth was overestimated (t = −5.5, df = 4, P = 0.005) for fish on the 12-d cycle. However, model errors detected between observed and predicted values were low, ranging from −10.1% to +7.8%. We found that juvenile yellow perch exhibited compensatory growth (CG), but none of the feed–fast treatments resulted in growth overcompensation. Likewise, we found no evidence that respiration rates varied with CG, implying that yellow perch bioenergetics models could be used to predict the effects of feeding history and CG response on food consumption and fish growth.

50 CFR Table 37 to Part 679 - GOA Amendment 80 Sideboard Limit for Groundfish for the Amendment 80 Sector

Code of Federal Regulations, 2014 CFR

2014-10-01

...% of the TAC. Pacific ocean perch 96.1% of the TAC. Pelagic shelf rockfish 89.6% of the TAC. Central GOA Pacific cod 4.4% of the TAC. Pacific ocean perch Subject to regulations in subpart G to this part... regulations in subpart G to this part. Western GOA Pacific cod 2.0% of the TAC. Pacific ocean perch 99.4% of...

50 CFR Table 37 to Part 679 - GOA Amendment 80 Sideboard Limit for Groundfish for the Amendment 80 Sector

Code of Federal Regulations, 2011 CFR

2011-10-01

...% of the TAC. Pacific ocean perch 96.1% of the TAC. Pelagic shelf rockfish 89.6% of the TAC. Central GOA Pacific cod 4.4% of the TAC. Pacific ocean perch Subject to regulations in subpart G to this part... regulations in subpart G to this part. Western GOA Pacific cod 2.0% of the TAC. Pacific ocean perch 99.4% of...

50 CFR Table 37 to Part 679 - GOA Amendment 80 Sideboard Limit for Groundfish for the Amendment 80 Sector

Code of Federal Regulations, 2010 CFR

2010-10-01

...% of the TAC. Pacific ocean perch 96.1% of the TAC. Pelagic shelf rockfish 89.6% of the TAC. Central GOA Pacific cod 4.4% of the TAC. Pacific ocean perch Subject to regulations in subpart G to this part... regulations in subpart G to this part. Western GOA Pacific cod 2.0% of the TAC. Pacific ocean perch 99.4% of...

50 CFR Table 37 to Part 679 - GOA Amendment 80 Sideboard Limit for Groundfish for the Amendment 80 Sector

Code of Federal Regulations, 2012 CFR

2012-10-01

...% of the TAC. Pacific ocean perch 96.1% of the TAC. Pelagic shelf rockfish 89.6% of the TAC. Central GOA Pacific cod 4.4% of the TAC. Pacific ocean perch Subject to regulations in subpart G to this part... regulations in subpart G to this part. Western GOA Pacific cod 2.0% of the TAC. Pacific ocean perch 99.4% of...

50 CFR Table 37 to Part 679 - GOA Amendment 80 Sideboard Limit for Groundfish for the Amendment 80 Sector

Code of Federal Regulations, 2013 CFR

2013-10-01

...% of the TAC. Pacific ocean perch 96.1% of the TAC. Pelagic shelf rockfish 89.6% of the TAC. Central GOA Pacific cod 4.4% of the TAC. Pacific ocean perch Subject to regulations in subpart G to this part... regulations in subpart G to this part. Western GOA Pacific cod 2.0% of the TAC. Pacific ocean perch 99.4% of...

Characterization of perch rhabdovirus (PRV) in farmed grayling Thymallus thymallus.

PubMed

Gadd, Tuija; Viljamaa-Dirks, Satu; Holopainen, Riikka; Koski, Perttu; Jakava-Viljanen, Miia

2013-10-11

Two Finnish fish farms experienced elevated mortality rates in farmed grayling Thymallus thymallus fry during the summer months, most typically in July. The mortalities occurred during several years and were connected with a few neurological disorders and peritonitis. Virological investigation detected an infection with an unknown rhabdovirus. Based on the entire glycoprotein (G) and partial RNA polymerase (L) gene sequences, the virus was classified as a perch rhabdovirus (PRV). Pairwise comparisons of the G and L gene regions of grayling isolates revealed that all isolates were very closely related, with 99 to 100% nucleotide identity, which suggests the same origin of infection. Phylogenetic analysis demonstrated that they were closely related to the strain isolated from perch Perca fluviatilis and sea trout Salmo trutta trutta caught from the Baltic Sea. The entire G gene sequences revealed that all Finnish grayling isolates, and both the perch and sea trout isolates, were most closely related to a PRV isolated in France in 2004. According to the partial L gene sequences, all of the Finnish grayling isolates were most closely related to the Danish isolate DK5533 from pike. The genetic analysis of entire G gene and partial L gene sequences showed that the Finnish brown trout isolate ka907_87 shared only approximately 67 and 78% identity, respectively, with our grayling isolates. The grayling isolates were also analysed by an immunofluorescence antibody test. This is the first report of a PRV causing disease in grayling in Finland.

Using consumption rate to assess potential predators for biological control of white perch

USGS Publications Warehouse

Gosch, N.J.C.; Pope, K.L.

2011-01-01

Control of undesirable fishes is important in aquatic systems, and using predation as a tool for biological control is an attractive option to fishery biologists. However, determining the appropriate predators for biological control is critical for success. The objective of this study was to evaluate the utility of consumption rate as an index to determine the most effective predators for biological control of an invasive fish. Consumption rate values were calculated for nine potential predators that prey on white perch Morone americana in Branched Oak and Pawnee reservoirs, Nebraska. The consumption rate index provided a unique and insightful means of determining the potential effectiveness of each predator species in controlling white perch. Cumulative frequency distributions facilitated interpretation by providing a graphical presentation of consumption rates by all individuals within each predator species. Largemouth bass Micropterus salmoides, walleye Sander vitreus and sauger S. canadensis were the most efficient white perch predators in both reservoirs; however, previous attempts to increase biomass of these predators have failed suggesting that successful biological control is unlikely using existing predator species in these Nebraska reservoirs. ?? 2011 ONEMA.

Decrease of Population Divergence in Eurasian Perch (Perca fluviatilis) in Browning Waters: Role of Fatty Acids and Foraging Efficiency

PubMed Central

Scharnweber, Kristin; Strandberg, Ursula; Karlsson, Konrad; Eklöv, Peter

2016-01-01

Due to altered biogeochemical processes related to climate change, highly colored dissolved organic carbon (DOC) from terrestrial sources will lead to a water “brownification” in many freshwater systems of the Northern Hemisphere. This will create deteriorated visual conditions that have been found to affect habitat-specific morphological variations in Eurasian perch (Perca fluviatilis) in a previous study. So far, potential drivers and ultimate causes of these findings have not been identified. We conducted a field study to investigate the connection between morphological divergence and polyunsaturated fatty acid (PUFA) composition of perch from six lakes across a gradient of DOC concentration. We expected a decrease in the prevalence of PUFAs, which are important for perch growth and divergence with increasing DOC concentrations, due to the restructuring effects of DOC on aquatic food webs. In general, rate of morphological divergence in perch decreased with increasing DOC concentrations. Proportions of specific PUFAs (22:6n-3, 18:3n-3, 20:5n-3, and 20:4n-6) identified to primarily contribute to overall differences between perch caught in clear and brown-water lakes tended to be connected to overall decline of morphological divergence. However, no overall significant relationship was found, indicating no severe limitation of essential fatty acids for perch inhabiting brown water lakes. We further broaden our approach by conducting a laboratory experiment on foraging efficiency of perch. Therefore, we induced pelagic and littoral phenotypes by differences in habitat-structure and feeding mode and recorded attack rate in a feeding experiment. Generally, fish were less efficient in foraging on littoral prey (Ephemeroptera) when visual conditions were degraded by brown water color. We concluded that browning water may have a strong effect on the forager’s ability to find particular food resources, resulting in the reduced development of evolutionary traits

Standardization of Clinical Assessment and Sample Collection Across All PERCH Study Sites

PubMed Central

Prosperi, Christine; Baggett, Henry C.; Brooks, W. Abdullah; Deloria Knoll, Maria; Hammitt, Laura L.; Howie, Stephen R. C.; Kotloff, Karen L.; Levine, Orin S.; Madhi, Shabir A.; Murdoch, David R.; O’Brien, Katherine L.; Thea, Donald M.; Awori, Juliet O.; Bunthi, Charatdao; DeLuca, Andrea N.; Driscoll, Amanda J.; Ebruke, Bernard E.; Goswami, Doli; Hidgon, Melissa M.; Karron, Ruth A.; Kazungu, Sidi; Kourouma, Nana; Mackenzie, Grant; Moore, David P.; Mudau, Azwifari; Mwale, Magdalene; Nahar, Kamrun; Park, Daniel E.; Piralam, Barameht; Seidenberg, Phil; Sylla, Mamadou; Feikin, Daniel R.; Scott, J. Anthony G.; O’Brien, Katherine L.; Levine, Orin S.; Knoll, Maria Deloria; Feikin, Daniel R.; DeLuca, Andrea N.; Driscoll, Amanda J.; Fancourt, Nicholas; Fu, Wei; Hammitt, Laura L.; Higdon, Melissa M.; Kagucia, E. Wangeci; Karron, Ruth A.; Li, Mengying; Park, Daniel E.; Prosperi, Christine; Wu, Zhenke; Zeger, Scott L.; Watson, Nora L.; Crawley, Jane; Murdoch, David R.; Brooks, W. Abdullah; Endtz, Hubert P.; Zaman, Khalequ; Goswami, Doli; Hossain, Lokman; Jahan, Yasmin; Ashraf, Hasan; Howie, Stephen R. C.; Ebruke, Bernard E.; Antonio, Martin; McLellan, Jessica; Machuka, Eunice; Shamsul, Arifin; Zaman, Syed M.A.; Mackenzie, Grant; Scott, J. Anthony G.; Awori, Juliet O.; Morpeth, Susan C.; Kamau, Alice; Kazungu, Sidi; Kotloff, Karen L.; Tapia, Milagritos D.; Sow, Samba O.; Sylla, Mamadou; Tamboura, Boubou; Onwuchekwa, Uma; Kourouma, Nana; Toure, Aliou; Madhi, Shabir A.; Moore, David P.; Adrian, Peter V.; Baillie, Vicky L.; Kuwanda, Locadiah; Mudau, Azwifarwi; Groome, Michelle J.; Baggett, Henry C.; Thamthitiwat, Somsak; Maloney, Susan A.; Bunthi, Charatdao; Rhodes, Julia; Sawatwong, Pongpun; Akarasewi, Pasakorn; Thea, Donald M.; Mwananyanda, Lawrence; Chipeta, James; Seidenberg, Phil; Mwansa, James; wa Somwe, Somwe; Kwenda, Geoffrey

2017-01-01

Abstract Background. Variable adherence to standardized case definitions, clinical procedures, specimen collection techniques, and laboratory methods has complicated the interpretation of previous multicenter pneumonia etiology studies. To circumvent these problems, a program of clinical standardization was embedded in the Pneumonia Etiology Research for Child Health (PERCH) study. Methods. Between March 2011 and August 2013, standardized training on the PERCH case definition, clinical procedures, and collection of laboratory specimens was delivered to 331 clinical staff at 9 study sites in 7 countries (The Gambia, Kenya, Mali, South Africa, Zambia, Thailand, and Bangladesh), through 32 on-site courses and a training website. Staff competency was assessed throughout 24 months of enrollment with multiple-choice question (MCQ) examinations, a video quiz, and checklist evaluations of practical skills. Results. MCQ evaluation was confined to 158 clinical staff members who enrolled PERCH cases and controls, with scores obtained for >86% of eligible staff at each time-point. Median scores after baseline training were ≥80%, and improved by 10 percentage points with refresher training, with no significant intersite differences. Percentage agreement with the clinical trainer on the presence or absence of clinical signs on video clips was high (≥89%), with interobserver concordance being substantial to high (AC1 statistic, 0.62–0.82) for 5 of 6 signs assessed. Staff attained median scores of >90% in checklist evaluations of practical skills. Conclusions. Satisfactory clinical standardization was achieved within and across all PERCH sites, providing reassurance that any etiological or clinical differences observed across the study sites are true differences, and not attributable to differences in application of the clinical case definition, interpretation of clinical signs, or in techniques used for clinical measurements or specimen collection. PMID:28575355

Histopathological observation of lymphocystis disease and lymphocystis disease virus (LCDV) detection in cultured diseased Sebastes schlegeli

NASA Astrophysics Data System (ADS)

Sheng, Xiuzhen; Zhan, Wenbin; Xu, Songjuan; Cheng, Shunfeng

2007-10-01

Lymphocystis nodules occurring in the cultured sting fish Sebastes schlegeli were observed under light and electron microscope. Lymphocystis disease virus (LCDV) in the tissues of diseased fish was detected with indirect immunofluorescence test (IFAT). Results showed that lymphocystis cells had overly irregular nuclei, basophilic intracytoplasmic inclusion bodies with virions budding from the surface, and hyaline capsules outside the cell membrane. Numerous virus particles about 200 nm in diameter scattered in the cytoplasm, electron-dense particles 70 80 nm in diameter filled in perinuclear cisterna, and membrane-enveloped particles with electron-dense core of 70 80 nm appeared around cellular nucleus. IFAT using monoclonal antibody against LCDV from Paralichthys olivaceus revealed that specific green fluorescence was present in the cytoplasm of lymphocystis cells, epithelium of stomach, gill lamellae, and muscular fibers under epidermis of S. schlegeli, just as that in the cytoplasm of lymphocystis cells of P. olivaceus, suggesting the presence of LCDV in these tissues.

Baseline concentrations of biliary PAH metabolites in perch (Perca fluviatilis) in the open Gulf of Finland and in two coastal areas

NASA Astrophysics Data System (ADS)

Vuorinen, Pekka J.; Saulamo, Kari; Lecklin, Tiina; Rahikainen, Mika; Koivisto, Pertti; Keinänen, Marja

2017-07-01

Female perch (Perca fluviatilis) were sampled annually in late summer from 2006 to 2009 from the open sea of the eastern Gulf of Finland off Haapasaari island to monitor baseline biliary PAH metabolite concentrations. In addition, two coastal locations were sampled in 2008. PAH metabolite concentrations were compared between the open sea and coastal samples and between the sampling years and examined in relation to the body characteristics of perch. Of the PAH metabolites, only 1-hydroxypyrene (1-OH pyrene) was detected at quantifiable levels in the bile of nearly all perch individuals. There were some annual differences but no temporal trend in the concentration of biliary 1-OH pyrene in perch from Haapasaari. At the coastal locations, 1-OH pyrene concentrations in the bile of perch were significantly higher than in the open sea Haapasaari area, probably due to greater contamination of the coastal sites and differences in feeding behaviour. No correlations between the body characteristics of perch and 1-OH pyrene concentrations were detected. It is concluded that PAH metabolites in the bile of fish could be measured in the Gulf of Finland to detect oil spills in the open sea, and the cost-effective total fluorescence method could be used in such monitoring programmes.

Evidence of impaired health in yellow perch (Perca flavescens) from a biological mercury hotspot in northeastern North America.

PubMed

Batchelar, Katharina L; Kidd, Karen A; Drevnick, Paul E; Munkittrick, Kelly R; Burgess, Neil M; Roberts, Aaron P; Smith, James D

2013-03-01

Few studies have investigated the effects of mercury (Hg) on wild fish from remote areas, even though these fish can have high total Hg concentrations. In Kejimkujik National Park and National Historic Site (KNPNHS), Nova Scotia, Canada, concentrations of total Hg in many yellow perch (Perca flavescens) currently exceed the estimated threshold level for adverse effects in fish (0.2 µg Hg g(-1) (wet wt), whole body). To determine whether Hg exposure is adversely affecting the general health of these fish, the authors collected male and female perch in the fall of 2009 and 2010 from 12 lakes within KNPNHS. The health endpoints condition, liver somatic index (LSI), and macrophage aggregates (MAs; indicators of oxidative stress and tissue damage) in the liver, kidney, and spleen were examined, and in female perch were compared between lakes and related to Hg concentrations measured in the muscle and liver tissue. No negative relationships between fish condition or LSI and Hg were found. However, within the liver, kidney, and spleen tissues of females, the relative area occupied by MAs was positively related to both muscle and liver Hg concentrations, indicating the health of these perch was adversely affected at the cellular level. These findings raise concerns for the health of these perch as well as for other wild fish populations known to have similarly elevated Hg concentrations. Copyright © 2013 SETAC.

Potential use of offshore marine structures in rebuilding an overfished rockfish species, bocaccio (Sebastes paucispinis)

USGS Publications Warehouse

Love, M.S.; Schroeder, D.M.; Lenarz, W.; MacCall, A.; Bull, A.S.; Thorsteinson, L.

2006-01-01

Although bocaccio (Sebastes paucispinis) was an economically important rockfish species along the west coast of North America, overfishing has reduced the stock to about 7.4% of its former unfished population. In 2003, using a manned research submersible, we conducted fish surveys around eight oil and gas platforms off southern California as part of an assessment of the potential value of these structures as fish habitat. From these surveys, we estimated that there was a minimum of 430,000 juvenile bocaccio at these eight structures. We determined this number to be about 20% of the average number of juvenile bocaccio that survive annually for the geographic range of the species. When these juveniles become adults, they will contribute about one percent (0.8%) of the additional amount of fish needed to rebuild the Pacific Coast population. By comparison, juvenile bocaccio recruitment to nearshore natural nursery grounds, as determined through regional scuba surveys, was low in the same year. This research demonstrates that a relatively small amount of artificial nursery habitat may be quite valuable in rebuilding an overfished species.

Bird Perches Increase Forest Seeds on Puerto Rican Landslides.

Treesearch

Aaron B. Shiels; Lawrence R. Walker

2003-01-01

Landslides result in the loss of vertical vegetative structure, soil nutrients, and the soil seed bank. These losses impede timely recovery of tropical forest communities. In this study we added bird perches to six Puerto Rican landslides with three types of surfaces (bare, climbing fern, grass) in an effort to facilitate inputs of forest seeds through bird dispersal...

Recruitment synchrony of yellow perch (Perca flavescens, Percidae) in the Great Lakes region, 1966–2008

USGS Publications Warehouse

Honsey, Andrew E.; Bunnell, David B.; Troy, Cary D.; Fielder, David G.; Thomas, Michael V.; Knight, Carey T.; Chong, Stephen; Hook, Tomas O.

2016-01-01

Population-level reproductive success (recruitment) of many fish populations is characterized by high inter-annual variation and related to annual variation in key environmental factors (e.g., climate). When such environmental factors are annually correlated across broad spatial scales, spatially separated populations may display recruitment synchrony (i.e., the Moran effect). We investigated inter-annual (1966–2008) variation in yellow perch (Perca flavescens, Percidae) recruitment using 16 datasets describing populations located in four of the five Laurentian Great Lakes (Erie, Huron, Michigan, and Ontario) and Lake St. Clair. We indexed relative year class strength using catch-curve residuals for each year-class across 2–4 years and compared relative year-class strength among sampling locations. Results indicate that perch recruitment is positively synchronized across the region. In addition, the spatial scale of this synchrony appears to be broader than previous estimates for both yellow perch and freshwater fish in general. To investigate potential factors influencing relative year-class strength, we related year-class strength to regional indices of annual climatic conditions (spring-summer air temperature, winter air temperature, and spring precipitation) using data from 14 weather stations across the Great Lakes region. We found that mean spring-summer temperature is significantly positively related to recruitment success among Great Lakes yellow perch populations.

Minimum size limits for yellow perch (Perca flavescens) in western Lake Erie

USGS Publications Warehouse

Hartman, Wilbur L.; Nepszy, Stephen J.; Scholl, Russell L.

1980-01-01

During the 1960's yellow perch (Perca flavescens) of Lake Erie supported a commercial fishery that produced an average annual catch of 23 million pounds, as well as a modest sport fishery. Since 1969, the resource has seriously deteriorated. Commercial landings amounted to only 6 million pounds in 1976, and included proportionally more immature perch than in the 1960's. Moreover, no strong year classes were produced between 1965 and 1975. An interagency technical committee was appointed in 1975 by the Lake Erie Committee of the Great Lakes Fishery Commission to develop an interim management strategy that would provide for greater protection of perch in western Lake Erie, where declines have been the most severe. The committee first determined the age structure, growth and mortality rates, maturation schedule, and length-fecundity relationship for the population, and then applied Ricker-type equilibrium yield models to determine the effects of various minimum length limits on yield, production, average stock weight, potential egg deposition, and the Abrosov spawning frequency indicator (average number of spawning opportunities per female). The committee recommended increasing the minimum length limit of 5.0 inches to at least 8.5 inches. Theoretically, this change would increase the average stock weight by 36% and potential egg deposition by 44%, without significantly decreasing yield. Abrosov's spawning frequency indicator would rise from the existing 0.6 to about 1.2.

The effect of perches in cages during pullet rearing and egg laying on hen performance, foot health, and plumage

USDA-ARS?s Scientific Manuscript database

Our objective was to determine if perch availability during all or part of the life cycle of caged Hy-Line W-36 chickens affected egg traits, foot health, and feather condition. Using a 2 x 2 factorial arrangement, treatment 1 represented control chickens which never had access to perches during the...

Lake Erie Yellow perch age estimation based on three structures: Precision, processing times, and management implications

USGS Publications Warehouse

Vandergoot, C.S.; Bur, M.T.; Powell, K.A.

2008-01-01

Yellow perch Perca flavescens support economically important recreational and commercial fisheries in Lake Erie and are intensively managed. Age estimation represents an integral component in the management of Lake Erie yellow perch stocks, as age-structured population models are used to set safe harvest levels on an annual basis. We compared the precision associated with yellow perch (N = 251) age estimates from scales, sagittal otoliths, and anal spine sections and evaluated the time required to process and estimate age from each structure. Three readers of varying experience estimated ages. The precision (mean coefficient of variation) of estimates among readers was 1% for sagittal otoliths, 5-6% for anal spines, and 11-13% for scales. Agreement rates among readers were 94-95% for otoliths, 71-76% for anal spines, and 45-50% for scales. Systematic age estimation differences were evident among scale and anal spine readers; less-experienced readers tended to underestimate ages of yellow perch older than age 4 relative to estimates made by an experienced reader. Mean scale age tended to underestimate ages of age-6 and older fish relative to otolith ages estimated by an experienced reader. Total annual mortality estimates based on scale ages were 20% higher than those based on otolith ages; mortality estimates based on anal spine ages were 4% higher than those based on otolith ages. Otoliths required more removal and preparation time than scales and anal spines, but age estimation time was substantially lower for otoliths than for the other two structures. We suggest the use of otoliths or anal spines for age estimation in yellow perch (regardless of length) from Lake Erie and other systems where precise age estimates are necessary, because age estimation errors resulting from the use of scales could generate incorrect management decisions. ?? Copyright by the American Fisheries Society 2008.

Genetic diversity and associated pathology of rhabdovirus infections in farmed and wild perch Perca fluviatilis in Ireland.

PubMed

Ruane, N M; Rodger, H D; McCarthy, L J; Swords, D; Dodge, M; Kerr, R C; Henshilwood, K; Stone, D M

2014-12-02

Rhabdovirus infections are an emerging problem for both wild and farmed freshwater fish in Northern Europe. In October 2005, a clinical outbreak with an approximate mortality rate of 40% occurred in a single batch of juvenile perch on a farm in the Republic of Ireland. Clinical signs developed slowly and were consistent with a perch rhabdovirus infection: signs included haemorrhages at the base of the fins and apparent impairment of the central nervous system (manifested as loss of equilibrium and erratic swimming behaviour). Studies suggest that the infected fish originated from a hatchery within the country which relied on wild fish broodstock to supplement the production of perch juveniles. A related rhabdovirus was subsequently isolated from this hatchery. Virus isolation studies have shown that rhabdoviruses were often isolated from wild fish in the vicinity of the hatchery between 1993 and 2005. All isolates were analysed using a generic primer set specific for the L gene of fish vesiculotype viruses. Phylogenetic analysis revealed that all isolates recovered from perch clustered together with the European lake trout rhabdovirus (903/87) of the genus Perhabdovirus. In addition to this, anguillid rhabdovirus was isolated from eel, and the partial L-gene sequence of a previously reported isolate from tench clustered with the pike fry rhabdoviruses, in the genus Sprivivirus.

Hydrological connectivity of perched aquifers and regional aquifers in semi-arid environments: a case study from Namibia

NASA Astrophysics Data System (ADS)

Hamutoko, J. T.; Wanke, H.

2017-12-01

Integrated isotopic and hydrological tracers along with standard hydrological data are used to understand complex dry land hydrological processes on different spatial and temporal scales. The objective of this study is to analyse the relationship between the perched aquifers and the regional aquifer using hydrochemical data and isotopic composition in the Cuvelai-Etosha Basin in Namibia. This relation between the aquifers will aid in understanding groundwater recharge processes and flow dynamics. Perched aquifers are discontinuous shallow aquifers with water level ranging from 0 to 30 meters below ground level. The regional aquifer occurs in semi-consolidated sandstone at depths between about 60 and 160 meters below ground level. Water samples were collected from both aquifers in 10 villages and were analysed for major ions and stable isotopes. The results show overlapping hydrochemistry and isotopic compositions of both aquifers in 8 villages which suggest the possibility of perched aquifer water infiltrating into the regional aquifer. In two villages the hydrochemistry and isotopic composition of the aquifers are totally different and this suggests that there is no interaction between this aquifers. Areas where perched aquifers are connected to regional aquifers maybe recharge zones. These finding have important implications for groundwater resource management.

Short-Term Fidelity, Habitat Use and Vertical Movement Behavior of the Black Rockfish Sebastes schlegelii as Determined by Acoustic Telemetry

PubMed Central

Zhang, Yingqiu; Xu, Qiang; Alós, Josep; Liu, Hui; Xu, Qinzeng; Yang, Hongsheng

2015-01-01

The recent miniaturization of acoustic tracking devices has allowed fishery managers and scientists to collect spatial and temporal data for sustainable fishery management. The spatial and temporal dimensions of fish behavior (movement and/or vertical migrations) are particularly relevant for rockfishes (Sebastes spp.) because most rockfish species are long-lived and have high site fidelity, increasing their vulnerability to overexploitation. In this study, we describe the short-term (with a tracking period of up to 46 d) spatial behavior, as determined by acoustic tracking, of the black rockfish Sebastes schlegelii, a species subject to overexploitation in the Yellow Sea of China. The average residence index (the ratio of detected days to the total period from release to the last detection) in the study area was 0.92 ± 0.13, and most of the tagged fish were detected by only one region of the acoustic receiver array, suggesting relatively high site fidelity to the study area. Acoustic tracking also suggested that this species is more frequently detected during the day than at night in our study area. However, the diel detection periodicity (24 h) was only evident for certain periods of the tracking time, as revealed by a continuous wavelet transform. The habitat selection index of tagged S. schlegelii suggested that S. schlegelii preferred natural reefs, mixed sand/artificial reef bottoms and mixed bottoms of boulder, cobble, gravel and artificial reefs. The preference of this species for the artificial reefs that were recently deployed in the study area suggests that artificial seascapes may be effective management tools to attract individuals. The vertical movement of tagged S. schlegelii was mostly characterized by bottom dwelling behavior, and there was high individual variability in the vertical migration pattern. Our results have important implications for S. schlegelii catchability, the implementation of marine protected areas, and the identification of key

Seasonal and Sex-Specific mRNA Levels of Key Endocrine Genes in Adult Yellow Perch (Perca flavescens) from Lake Erie

USDA-ARS?s Scientific Manuscript database

Yellow perch exhibit a sexual size dimorphism (SSD) where females grow faster and larger than males and estrogen preferentially stimulates growth in females. In an effort to gain more understanding of yellow perch endocrinology, real-time quantitative PCR (qPCR) was used to measure pituitary, liver...

Radiographic evaluation of perching-joint angles in cockatiels (Nymphicus hollandicus), Hispaniolan Amazon parrots (Amazona ventralis), and barred owls (Strix varia).

PubMed

Bonin, Glen; Lauer, Susanne K; Guzman, David Sanchez-Migallon; Nevarez, Javier; Tully, Thomas N; Hosgood, Giselle; Gaschen, Lorrie

2009-06-01

Information on perching-joint angles in birds is limited. Joint immobilization in a physiologic perching angle has the potential to result more often in complete restoration of limb function. We evaluated perching-joint angles in 10 healthy cockatiels (Nymphicus hollandicus), 10 Hispaniolan Amazons (Amazona ventralis), and 9 barred owls (Strix varia) and determined intra- and interobserver variability for goniometric measurements in 2 different radiographic projections. Intra- and interobserver variation was less than 7% for all stifle and intertarsal joint measurements but frequently exceeded 10% for the hip-joint measurements. Hip, stifle, and intertarsal perching angles differed significantly among cockatiels, Hispaniolan Amazon parrots, and barred owls. The accuracy of measurements performed on straight lateral radiographic projections with superimposed limbs was not consistently superior to measurements on oblique projections with a slightly rotated pelvis. Stifle and intertarsal joint angles can be measured on radiographs by different observers with acceptable variability, but intra- and interobserver variability for hip-joint-angle measurements is higher.

Tropical fish in a warming world: thermal tolerance of Nile perch Lates niloticus (L.) in Lake Nabugabo, Uganda.

PubMed

Chrétien, Emmanuelle; Chapman, Lauren J

2016-01-01

Key to predicting the response of fishes to climate change is quantifying how close fish are to their critical thermal limits in nature and their ability to adjust their thermal sensitivity to maintain performance. Here, we evaluated the effects of body size and habitat on aerobic scope (AS) and thermal tolerance of Nile perch Lates niloticus (L.), a fish of great economic and food security importance in East Africa, using respirometry and critical thermal maximum (CTmax) trials. Juvenile Nile perch from distinct habitats (high or low dissolved oxygen concentrations) of Lake Nabugabo, Uganda were exposed for 4.6 ± 0.55 days to a temperature treatment (25.5, 27.5, 29.5 or 31.5°C) prior to experimentation, with the lowest temperature corresponding to the mean annual daytime temperature in Lake Nabugabo and the highest temperature being 3°C higher than the maximal monthly average. As expected, metabolic rates increased with body mass. Although resting metabolic rate increased with temperature, maximal metabolic rate showed no change. Likewise, AS did not vary across treatments. The CTmax increased with acclimation temperature. There was no effect of habitat on maximal metabolic rate, AS or CTmax; however, there was a trend towards a lower resting metabolic rate for Nile perch captured in the low-dissolved oxygen habitat than in well-oxygenated waters. This study shows that juvenile Nile perch maintain a large AS at temperatures near the upper limit of their natural thermal range and provides evidence that Nile perch have physiological mechanisms to deal with acute exposure to thermal stress.

Phylogenetic analysis and molecular methods for the detection of lymphocystis disease virus from yellow perch, Perca flavescens (Mitchell).

PubMed

Palmer, L J; Hogan, N S; van den Heuvel, M R

2012-09-01

Lymphocystis disease is a prevalent, non-fatal disease that affects many teleost fish and is caused by the DNA virus lymphocystis disease virus (LCDV). Lymphocystis-like lesions have been observed in yellow perch, Perca flavescens (Mitchell), in lakes in northern Alberta, Canada. In an effort to confirm the identity of the virus causing these lesions, DNA was extracted from these lesions and PCR with genotype generic LCDV primers specific to the major capsid protein (MCP) gene was performed. A 1357-base pair nucleotide sequence corresponding to a peptide length of 452 amino acids of the MCP gene was sequenced, confirming the lesions as being lymphocystis disease lesions. Phylogenetic analysis of the generated amino acid sequence revealed the perch LCDV isolate to be a distinct and novel genotype. From the obtained sequence, a real-time PCR identification method was developed using fluorgenic LUX primers. The identification method was used to detect the presence/absence of LCDV in yellow perch from two lakes, one where lymphocystis disease was observed to occur and the other where the disease had not been observed. All samples of fin, spleen and liver tested negative for LCDV in the lake where lymphocystis disease had not been observed. The second lake had a 2.6% incidence of LCD, and virus was detected in tissue samples from all individuals tested regardless of whether they were expressing the disease or not. However, estimated viral copy number in spleen and liver of symptomatic perch was four orders of magnitude higher than that in asymptomatic perch. © 2012 Blackwell Publishing Ltd.

An update of the distribution of selected radiochemical and chemical constituents in perched ground water, Idaho National Laboratory, Idaho, Emphasis 1999-2001

USGS Publications Warehouse

Davis, Linda C.

2006-01-01

Radiochemical and chemical wastes generated at facilities at the Idaho National Laboratory (INL) were discharged since 1952 to infiltration ponds at the Reactor Technology Complex (RTC) (known as the Test Reactor Area [TRA] until 2005), and the Idaho Nuclear Technology and Engineering Center (INTEC) and buried at the Radioactive Waste Management Complex (RWMC). Disposal of wastewater to infiltration ponds and infiltration of surface water at waste burial sites resulted in formation of perched ground water in basalts and in sedimentary interbeds above the Snake River Plain aquifer. Perched ground water is an integral part of the pathway for waste-constituent migration to the aquifer. The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, maintains ground-water monitoring networks at the INL to determine hydrologic trends, and to monitor the movement of radiochemical and chemical constituents in wastewater discharged from facilities to both perched ground water and the aquifer. This report presents an analysis of water-quality and water-level data collected from wells completed in perched ground water at the INL during 1999-2001, and summarizes historical disposal data and water-level-and water-quality trends. At the RTC, tritium, strontium-90, cesium-137, dissolved chromium, chloride, sodium, and sulfate were monitored in shallow and deep perched ground water. In shallow perched ground water, no tritium was detected above the reporting level. In deep perched ground water, tritium concentrations generally decreased or varied randomly during 1999-2001. During October 2001, tritium concentrations ranged from less than the reporting level to 39.4?1.4 picocuries per milliliter (pCi/mL). Reportable concentrations of tritium during July-October 2001 were smaller than the reported concentrations measured during July-December 1998. Tritium concentrations in water from wells at the RTC were likely affected by: well's distance from the

PERCH: A Unified Framework for Disease Gene Prioritization.

PubMed

Feng, Bing-Jian

2017-03-01

To interpret genetic variants discovered from next-generation sequencing, integration of heterogeneous information is vital for success. This article describes a framework named PERCH (Polymorphism Evaluation, Ranking, and Classification for a Heritable trait), available at http://BJFengLab.org/. It can prioritize disease genes by quantitatively unifying a new deleteriousness measure called BayesDel, an improved assessment of the biological relevance of genes to the disease, a modified linkage analysis, a novel rare-variant association test, and a converted variant call quality score. It supports data that contain various combinations of extended pedigrees, trios, and case-controls, and allows for a reduced penetrance, an elevated phenocopy rate, liability classes, and covariates. BayesDel is more accurate than PolyPhen2, SIFT, FATHMM, LRT, Mutation Taster, Mutation Assessor, PhyloP, GERP++, SiPhy, CADD, MetaLR, and MetaSVM. The overall approach is faster and more powerful than the existing quantitative method pVAAST, as shown by the simulations of challenging situations in finding the missing heritability of a complex disease. This framework can also classify variants of unknown significance (variants of uncertain significance) by quantitatively integrating allele frequencies, deleteriousness, association, and co-segregation. PERCH is a versatile tool for gene prioritization in gene discovery research and variant classification in clinical genetic testing. © 2016 The Authors. **Human Mutation published by Wiley Periodicals, Inc.

Cloning and expression analysis of vasa during the reproductive cycle of Korean rockfish, Sebastes schlegeli

NASA Astrophysics Data System (ADS)

Mu, Weijie; Wen, Haishen; He, Feng; Li, Jifang; Liu, Miao; Ma, Ruiqin; Zhang, Yuanqing; Hu, Jian; Qi, Baoxia

2013-03-01

Vasa, which is a conserved member of the DEAD-box protein family, plays an indispensable role in primordial germ cell proliferation. However, the expression of vasa gene during the reproductive cycle in ovoviviparous fish has not been documented. In this study, the full-length sequence of vasa was obtained from the ovary of Korean rockfish ( Sebastes schlegeli) using reverse transcription-PCR and rapid amplification of cDNA ends. The Vasa with a mature protein of 650 amino acids showed greatest homology (84%) with giant gourami ( Osphronemus goramy) and Pacific bluefin tuna ( Thunnus orientalis). The expression of vasa mRNA in Korean rockfish was detected in gonads only, suggesting its specific role in gonadal development. In addition, seasonal changes in the vasa expression levels were examined in gonads by quantitative real-time PCR. The vasa transcript levels in adult testis were found higher during spermatogenesis than during spermiation. The vasa transcript levels remained relatively high at the early ovary stage but declined during ovary maturation in adult female fish. These results suggest that the vasa gene play an important role in spermatogenesis and early oogenesis during the reproductive cycle of Korean rockfish.

Preferential flow, diffuse flow, and perching in an interbedded fractured-rock unsaturated zone

NASA Astrophysics Data System (ADS)

Nimmo, John R.; Creasey, Kaitlyn M.; Perkins, Kim S.; Mirus, Benjamin B.

2017-03-01

Layers of strong geologic contrast within the unsaturated zone can control recharge and contaminant transport to underlying aquifers. Slow diffuse flow in certain geologic layers, and rapid preferential flow in others, complicates the prediction of vertical and lateral fluxes. A simple model is presented, designed to use limited geological site information to predict these critical subsurface processes in response to a sustained infiltration source. The model is developed and tested using site-specific information from the Idaho National Laboratory in the Eastern Snake River Plain (ESRP), USA, where there are natural and anthropogenic sources of high-volume infiltration from floods, spills, leaks, wastewater disposal, retention ponds, and hydrologic field experiments. The thick unsaturated zone overlying the ESRP aquifer is a good example of a sharply stratified unsaturated zone. Sedimentary interbeds are interspersed between massive and fractured basalt units. The combination of surficial sediments, basalts, and interbeds determines the water fluxes through the variably saturated subsurface. Interbeds are generally less conductive, sometimes causing perched water to collect above them. The model successfully predicts the volume and extent of perching and approximates vertical travel times during events that generate high fluxes from the land surface. These developments are applicable to sites having a thick, geologically complex unsaturated zone of substantial thickness in which preferential and diffuse flow, and perching of percolated water, are important to contaminant transport or aquifer recharge.

Preferential flow, diffuse flow, and perching in an interbedded fractured-rock unsaturated zone

USGS Publications Warehouse

Nimmo, John R.; Creasey, Kaitlyn M; Perkins, Kimberlie; Mirus, Benjamin B.

2017-01-01

Layers of strong geologic contrast within the unsaturated zone can control recharge and contaminant transport to underlying aquifers. Slow diffuse flow in certain geologic layers, and rapid preferential flow in others, complicates the prediction of vertical and lateral fluxes. A simple model is presented, designed to use limited geological site information to predict these critical subsurface processes in response to a sustained infiltration source. The model is developed and tested using site-specific information from the Idaho National Laboratory in the Eastern Snake River Plain (ESRP), USA, where there are natural and anthropogenic sources of high-volume infiltration from floods, spills, leaks, wastewater disposal, retention ponds, and hydrologic field experiments. The thick unsaturated zone overlying the ESRP aquifer is a good example of a sharply stratified unsaturated zone. Sedimentary interbeds are interspersed between massive and fractured basalt units. The combination of surficial sediments, basalts, and interbeds determines the water fluxes through the variably saturated subsurface. Interbeds are generally less conductive, sometimes causing perched water to collect above them. The model successfully predicts the volume and extent of perching and approximates vertical travel times during events that generate high fluxes from the land surface. These developments are applicable to sites having a thick, geologically complex unsaturated zone of substantial thickness in which preferential and diffuse flow, and perching of percolated water, are important to contaminant transport or aquifer recharge.

Response of the insulin-like growth factor-1 (Igf1) system to nutritional status and growth rate variation in olive rockfish (Sebastes serranoides).

PubMed

Hack, Nicole L; Strobel, Jackson S; Journey, Meredith L; Beckman, Brian R; Lema, Sean C

2018-06-05

Growth performance in vertebrates is regulated by environmental factors including the quality and quantity of food, which influence growth via endocrine pathways such as the growth hormone (GH)/insulin-like growth factor somatotropic axis. In several teleost fishes, circulating concentrations of insulin-like growth factor-1 (Igf1) correlate positively with growth rate, and it has been proposed that plasma Igf1 levels may serve as an indicator of growth variation for fisheries and aquaculture applications. This study tested whether plasma Igf1 concentrations might serve as an indicator of somatic growth in olive rockfish (Sebastes serranoides), one species among dozens of rockfishes important to commercial and recreational fisheries in the Northern Pacific Ocean. Juvenile olive rockfish were reared under food ration treatments of 1% or 4% wet mass per d for 98 d to experimentally generate variation in growth. Juvenile rockfish in the 4% ration grew 60% more quickly in mass and 22% faster in length than fish in the 1% ration. Plasma Igf1 levels were elevated in rockfish under the 4% ration, and individual Igf1 levels correlated positively with growth rate, as well as with individual variation in hepatic igf1 mRNA levels. Transcripts encoding the Igf binding proteins (Igfbps) igfbp1a and igfbp1b were also at higher abundance in the liver of rockfish in the 1% ration treatment, while mRNAs for igfbp5a and igfbp5b were elevated in the skeletal muscle of 4% ration fish. These findings support the use of plasma Igf1 as a physiological index of growth rate variation in rockfish. Copyright © 2018. Published by Elsevier Inc.

Tropical fish in a warming world: thermal tolerance of Nile perch Lates niloticus (L.) in Lake Nabugabo, Uganda

PubMed Central

Chrétien, Emmanuelle; Chapman, Lauren J.

2016-01-01

Key to predicting the response of fishes to climate change is quantifying how close fish are to their critical thermal limits in nature and their ability to adjust their thermal sensitivity to maintain performance. Here, we evaluated the effects of body size and habitat on aerobic scope (AS) and thermal tolerance of Nile perch Lates niloticus (L.), a fish of great economic and food security importance in East Africa, using respirometry and critical thermal maximum (CTmax) trials. Juvenile Nile perch from distinct habitats (high or low dissolved oxygen concentrations) of Lake Nabugabo, Uganda were exposed for 4.6 ± 0.55 days to a temperature treatment (25.5, 27.5, 29.5 or 31.5°C) prior to experimentation, with the lowest temperature corresponding to the mean annual daytime temperature in Lake Nabugabo and the highest temperature being 3°C higher than the maximal monthly average. As expected, metabolic rates increased with body mass. Although resting metabolic rate increased with temperature, maximal metabolic rate showed no change. Likewise, AS did not vary across treatments. The CTmax increased with acclimation temperature. There was no effect of habitat on maximal metabolic rate, AS or CTmax; however, there was a trend towards a lower resting metabolic rate for Nile perch captured in the low-dissolved oxygen habitat than in well-oxygenated waters. This study shows that juvenile Nile perch maintain a large AS at temperatures near the upper limit of their natural thermal range and provides evidence that Nile perch have physiological mechanisms to deal with acute exposure to thermal stress. PMID:27990290

Impact of different colours of artificial light at night on melatonin rhythm and gene expression of gonadotropins in European perch.

PubMed

Brüning, Anika; Hölker, Franz; Franke, Steffen; Kleiner, Wibke; Kloas, Werner

2016-02-01

The distribution and intensity of artificial light at night, commonly referred to as light pollution, is consequently rising and progressively also ecological implications come to light. Low intensity light is known to suppress nocturnal melatonin production in several fish species. This study aims to examine the least suppressive light colour for melatonin excreted into the holding water and the influence of different light qualities and quantities in the night on gene expression of gonadotropins in fish. European perch (Perca fluviatilis) were exposed to light of different wavelengths during the night (blue, green, and red). Melatonin concentrations were measured from water samples every 3h during a 24h period. Gene expression of gonadotropins was measured in perch exposed to different light colours and was additionally examined for perch subjected to different intensities of white light (0 lx, 1 lx, 10 lx, 100 lx) during the night. All different light colours caused a significant drop of melatonin concentration; however, blue light was least suppressive. Gene expression of gonadotropins was not influenced by nocturnal light of different light colours, but in female perch gonadotropin expression was significantly reduced by white light already at the lowest level (1 lx). We conclude that artificial light with shorter wavelengths at night is less effective in disturbing biological rhythms of perch than longer wavelengths, coinciding with the light situation in freshwater habitats inhabited by perch. Different light colours in the night showed no significant effect on gonadotropin expression, but white light in the night can disturb reproductive traits already at very low light intensities. These findings indicate that light pollution has not only the potential to disturb the melatonin cycle but also the reproductive rhythm and may therefore have implications on whole species communities. Copyright © 2015 Elsevier B.V. All rights reserved.

Interspecies differences in the accumulation of tributyltin and its metabolites under dietary exposure in sea perch, Lateolabrax japonicus, and red sea bream, Pagrus major.

PubMed

Uno, Seiichi; Murakami, Masayo; Kokushi, Emiko; Koyama, Jiro

2011-02-01

Interspecies differences in the accumulation of dietary tributyltin (TBT) between sea perch, Lateolabrax japonicus, and red sea bream, Pagrus major, were studied. Although TBTs in both species reached steady-state condition in low-concentration group (L-group, 200 ng/g nominal concentration) by 1 week, it increased up to the end of exposure in high-concentration group (H-group, 3000 ng/g nominal concentration). In H-group, the accumulation rate of TBT in sea perch from 1 to 2 weeks was much higher than in red sea bream, which were 2.4-fold for sea perch and 1.7-fold for red sea bream, although TBT concentrations were similar between sea perch and red sea bream in L-group. Furthermore, in the H-group, the concentrations of TBT at 1 and 2 weeks were about 1.3- and 1.9-fold, respectively, higher in the sea perch than in the red sea bream. On the other hand, DBT residue in red sea bream was about 1.4-fold higher in sea perch for the L-group but concentrations were similar in both fishes for the H-group. These results suggest that red sea bream could metabolize faster the TBT to DBT than sea perch. This study also reveals that fish probably could absorb TBT through the food chain. The uptake of TBT by fish should be regarded in the real environment, because TBT concentration in seawater has been decreasing and now already at significantly low level. Copyright © 2009 Wiley Periodicals, Inc.

Relationship between mercury accumulation in young-of-the-year yellow perch and water-level fluctuations

USGS Publications Warehouse

Sorensen, J.A.; Kallemeyn, L.W.; Sydor, M.

2005-01-01

A three-year (2001−2003) monitoring effort of 14 northeastern Minnesota lakes was conducted to document relationships between water-level fluctuations and mercury bioaccumulation in young-of-the-year (YOY) yellow perch (Perca flavescens) collected in the fall of each year at fixed locations. Six of those lakes are located within or adjacent to Voyageurs National Park and are influenced by dams on the outlets of Rainy and Namakan lakes. One site on Sand Point Lake coincides with a location that has nine years of previous monitoring suitable for addressing the same issue over a longer time frame. Mean mercury concentrations in YOY yellow perch at each sampling location varied significantly from year to year. For the 12-year monitoring site on Sand Point Lake, values ranged from 38 ng gww-1 in 1998 to 200 ng gww-1 in 2001. For the 14-lake study, annual mean concentrations ranged by nearly a factor of 2, on average, for each lake over the three years of record. One likely factor responsible for these wide variations is that annual water-level fluctuations are strongly correlated with mercury levels in YOY perch for both data sets.

Are high perches in the blackcap Sylvia atricapilla song or listening posts? A sound transmission study.

PubMed

Mathevon, Nicolas; Dabelsteen, Torben; Blumenrath, Sandra H

2005-01-01

Birds often sing from high perches referred to as song posts. However, birds also listen and keep a lookout from these perches. We used a sound transmission experiment to investigate the changes for receiving and sending conditions that a territorial songbird may experience by moving upwards in the vegetation. Representative song elements of the blackcap Sylvia atricapilla were transmitted in a forest habitat in spring using a complete factorial design with natural transmission distances and speaker and microphone heights. Four aspects of sound degradation were quantified: signal-to-noise ratio, excess attenuation, distortion within the sounds determined as a blur ratio, and prolongation of the sounds with "tails" of echoes determined as a tail-to-signal ratio. All four measures indicated that degradation decreased with speaker and microphone height. However, the decrease was considerably higher for the microphone than for the speaker. This suggests that choosing high perches in a forest at spring results in more benefits to blackcaps in terms of improved communication conditions when they act as receivers than as senders.

Effects of predation stress and food ration on perch gut microbiota.

PubMed

Zha, Yinghua; Eiler, Alexander; Johansson, Frank; Svanbäck, Richard

2018-02-06

Gut microbiota provide functions of importance to influence hosts' food digestion, metabolism, and protection against pathogens. Factors that affect the composition and functions of gut microbial communities are well studied in humans and other animals; however, we have limited knowledge of how natural food web factors such as stress from predators and food resource rations could affect hosts' gut microbiota and how it interacts with host sex. In this study, we designed a two-factorial experiment exposing perch (Perca fluviatilis) to a predator (pike, Esox lucius), and different food ratios, to examine the compositional and functional changes of perch gut microbiota based on 16S rRNA amplicon sequencing. We also investigated if those changes are host sex dependent. We showed that overall gut microbiota composition among individual perch significantly responded to food ration and predator presence. We found that species richness decreased with predator presence, and we identified 23 taxa from a diverse set of phyla that were over-represented when a predator was present. For example, Fusobacteria increased both at the lowest food ration and at predation stress conditions, suggesting that Fusobacteria are favored by stressful situations for the host. In concordance, both food ration and predation stress seemed to influence the metabolic repertoire of the gut microbiota, such as biosynthesis of other secondary metabolites, metabolism of cofactors, and vitamins. In addition, the identified interaction between food ration and sex emphasizes sex-specific responses to diet quantity in gut microbiota. Collectively, our findings emphasize an alternative state in gut microbiota with responses to changes in natural food webs depending on host sex. The obtained knowledge from this study provided us with an important perspective on gut microbiota in a food web context.

Live transport of Yellow Perch and Nile Tilapia in AQUI-S 20E (10% Eugenol) at high loading densities

USGS Publications Warehouse

Cupp, Aaron R.; Schreier, Theresa M.; Schleis, Sue M.

2017-01-01

Fish transport costs are a substantial portion of the operational expenses for aquaculture facilities in the USA. Safely transporting higher loading densities of fish would benefit haulers by increasing efficiency and reducing costs, but research evaluating transport for individual species is generally lacking. In this study, Yellow Perch Perca flavescens and Nile Tilapia Oreochromis niloticus were transported for 6 h immersed in water containing AQUI-S 20E (10% eugenol) at fish loading densities of 240 g/L (2 lb/gal) for perch and 480 g/L (4 lb/gal) for tilapia. Survival was quantified for fish transported in AQUI-S 20E concentrations of (1) control or 0 mg/L of water, (2) 100 mg/L, or (3) 200 mg/L. Yellow Perch had 98–100% survival, and Nile Tilapia had 100% survival up to through 14 d after transport across all AQUI-S 20E levels, including the control. Eugenol concentrations decreased rapidly in transport tank water, and fish showed no signs of sedation by the end of transport. We conclude that live transport of Yellow Perch and Nile Tilapia at higher loading densities resulted in high survival regardless of the AQUI-S 20E concentrations we tested.

Experimental manipulations of tissue oxygen supply do not affect warming tolerance of European perch.

PubMed

Brijs, Jeroen; Jutfelt, Fredrik; Clark, Timothy D; Gräns, Albin; Ekström, Andreas; Sandblom, Erik

2015-08-01

A progressive inability of the cardiorespiratory system to maintain systemic oxygen supply at elevated temperatures has been suggested to reduce aerobic scope and the upper thermal limit of aquatic ectotherms. However, few studies have directly investigated the dependence of thermal limits on oxygen transport capacity. By manipulating oxygen availability (via environmental hyperoxia) and blood oxygen carrying capacity (via experimentally induced anaemia) in European perch (Perca fluviatilis Linneaus), we investigated the effects of oxygen transport capacity on aerobic scope and the critical thermal maximum (CT(max)). Hyperoxia resulted in a twofold increase in aerobic scope at the control temperature of 23°C, but this did not translate to an elevated CT(max) in comparison with control fish (34.6±0.1 versus 34.0±0.5°C, respectively). Anaemia (∼43% reduction in haemoglobin concentration) did not cause a reduction in aerobic scope or CT(max) (33.8±0.3°C) compared with control fish. Additionally, oxygen consumption rates of anaemic perch during thermal ramping increased in a similar exponential manner to that in control fish, highlighting that perch have an impressive capacity to compensate for a substantial reduction in blood oxygen carrying capacity. Taken together, these results indicate that oxygen limitation is not a universal mechanism determining the CT(max) of fishes. © 2015. Published by The Company of Biologists Ltd.

Dietary calcein marking of brook trout, Atlantic salmon, yellow perch, and coho salmon scales

USGS Publications Warehouse

Honeyfield, D.C.; Ostrowski, C.S.; Fletcher, J.W.; Mohler, J.W.

2006-01-01

Brook trout Salvelinus fontinalis, Atlantic salmon Salmo salar, coho salmon Oncorhynchus kisutch, and yellow perch Perca flavescens fed calcein for 5 d showed characteristic calcein scale marks 7-10 d postmarking. In fish fed 0.75 or 1.25 g of calcein per kilogram of feed, the percentage of fish that exhibited a calcein mark was 100% in brook trout, 93-98% in Atlantic salmon, 60% in yellow perch, and 0% in coho salmon. However, when coho salmon were fed 5.25 g calcein/kg feed, 100% marking was observed 7-10 d postmarking. Brook trout were successfully marked twice with distinct bands when fed calcein 5 months apart. Brook trout scale pixel luminosity increased as dietary calcein increased in experiment 2. For the second calcein mark, scale pixel luminosity from brook trout fed 1.25 g calcein/kg feed was numerically higher (P < 0.08) than scales from fish fed 0.75 g calcein/kg feed. Mean pixel luminosity of calcein-marked Atlantic salmon scales was 57.7 for fish fed 0.75 g calcein/kg feed and 55.2 for fish fed 1.25 g calcein/kg feed. Although feed acceptance presented a problem in yellow perch, these experiments provide evidence that dietary calcein is a viable tool for marking fish for stock identification. ?? Copyright by the American Fisheries Society 2006.

Perches and elevated platforms in commercial broiler farms: use and effect on walking ability, incidence of tibial dyschondroplasia and bone mineral content.

PubMed

Kaukonen, E; Norring, M; Valros, A

2017-05-01

Modern fast-growing broilers spend excessive periods resting and their activity further decreases with age. Inactivity has been suggested to increase impaired gait and the incidence of leg disorders. Tibial dyschondroplasia (TD) is a common leg pathology in broilers. A more complex environment might facilitate more activity and improve leg health. Perches or elevated platforms bring variety to broilers' environment and could motivate more locomotion. This study examined the impact of perches and elevated platforms on walking ability, the occurrence of TD and level of bone ash and mineral contents. The investigation was performed on four commercial broiler farms throughout six consecutive batches with platforms and four to five with perches. On each farm at least two separate houses were included, enabling the comparison of furnished flocks to control flocks during each batch. Plastic slats with ramp access elevated by 30 cm or wooden perches of 10 and 30 cm height were offered in the furnished house. Farmers recorded the platform and perch usage twice a week with a five-point scale. Gait was scored before slaughter on a six-point scale according to the Welfare Quality® assessment protocol for poultry. The severity of TD was determined using a four-point scale on farm from all birds gait scored as 3 and at slaughter from 200 birds/flock. Farmers estimated 50% to 100% of the platforms to be occupied in all flocks throughout the entire growing period. Only single birds were perching, thus perch structures were constantly evaluated to be empty. Due to the low use, the perch-equipped houses were excluded when analysing bone content, walking ability and TD. On average, 30% of the tested birds exhibited gait score ⩾3. Younger scoring age resulted in a lower mean gait score and a lower percentage of scores 3 and 4 to 5. Overall, 2.3% of the birds examined at slaughter and 3.5% of the birds with gait score 3 were affected by TD. Leg health was better in birds with access

Data Management and Data Quality in PERCH, a Large International Case-Control Study of Severe Childhood Pneumonia.

PubMed

Watson, Nora L; Prosperi, Christine; Driscoll, Amanda J; Higdon, Melissa M; Park, Daniel E; Sanza, Megan; DeLuca, Andrea N; Awori, Juliet O; Goswami, Doli; Hammond, Emily; Hossain, Lokman; Johnson, Catherine; Kamau, Alice; Kuwanda, Locadiah; Moore, David P; Neyzari, Omid; Onwuchekwa, Uma; Parker, David; Sapchookul, Patranuch; Seidenberg, Phil; Shamsul, Arifin; Siazeele, Kazungu; Srisaengchai, Prasong; Sylla, Mamadou; Levine, Orin S; Murdoch, David R; O'Brien, Katherine L; Wolff, Mark; Deloria Knoll, Maria

2017-06-15

The Pneumonia Etiology Research for Child Health (PERCH) study is the largest multicountry etiology study of pediatric pneumonia undertaken in the past 3 decades. The study enrolled 4232 hospitalized cases and 5325 controls over 2 years across 9 research sites in 7 countries in Africa and Asia. The volume and complexity of data collection in PERCH presented considerable logistical and technical challenges. The project chose an internet-based data entry system to allow real-time access to the data, enabling the project to monitor and clean incoming data and perform preliminary analyses throughout the study. To ensure high-quality data, the project developed comprehensive quality indicator, data query, and monitoring reports. Among the approximately 9000 cases and controls, analyzable laboratory results were available for ≥96% of core specimens collected. Selected approaches to data management in PERCH may be extended to the planning and organization of international studies of similar scope and complexity. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Of Paleo-Genes and Perch: What if an “Alien” Is Actually a Native?

PubMed Central

Stager, J. Curt; Sporn, Lee Ann; Johnson, Melanie; Regalado, Sean

2015-01-01

Documenting whether a biotic taxon is native or alien to an ecosystem has theoretical value for ecological and evolutionary studies, and has practical value because it can potentially identify a taxon as a desirable component of an ecosystem or target it for removal. In some cases, however, such background information is inadequate or unavailable. Here we use paleo-DNA to re-evaluate the historical status of yellow perch in the 6 million acre Adirondack State Park of northern New York. Yellow perch DNA in a 2200-year sediment record reveals a long-term native status for these supposedly alien fish and challenges assumptions that they necessarily exclude native trout from upland lakes. Similar approaches could be applied to other species with uncertain historical distributions and could help to identify unrecognized pockets of biodiversity. PMID:25751263

Development of an enzyme-linked immunosorbent assay for detection of chicken osteocalcin and its use in evaluation of perch effects on bone remodeling in caged White Leghorns.

PubMed

Jiang, S; Cheng, H W; Hester, P Y; Hou, J-F

2013-08-01

Osteocalcin (OC) is a sensitive biochemical marker for evaluating bone turnover in mammals. The role of avian OC is less clear because of the need for a chicken assay. Our objectives were to develop an assay using indirect competitive ELISA for detecting chicken serum OC and use the assay to examine the effects of perches on bone remodeling in caged hens. Anti-chicken OC polyclonal antibody was produced by immunization of rabbits with a recombinant OC from Escherichia coli. Chicken OC extracted from bone was used as a coated protein, and purified chicken OC was used for calibration. The limit of detection of the developed OC ELISA was 0.13 ng/mL. The intra- and interassay CV were <7 and <12%, respectively. The sensitivity of the developed OC ELISA was compared with a commercial Rat-Mid OC ELISA in laying hens housed in conventional cages with or without perches. Serum samples were collected from 71-wk-old White Leghorn hens subjected to 4 treatments. Treatment 1 was control chickens that never had access to perches during their life cycle. Treatment 2 chickens had perches during the pullet phase (0 to 16.9 wk of age), whereas treatment 3 chickens had perches only during the egg-laying phase of the life cycle (17 to 71 wk of age). Treatment 4 chickens always had access to perches (0 to 71 wk of age). Correlation between the 2 assays was 0.62 (P < 0.0001). Levels of serum OC using the developed chicken ELISA were higher than that detected using the Rat-Mid ELISA (P < 0.0001). Results from the chicken ELISA assay showed that hens with perch access had higher concentrations of serum OC than hens without perches during egg laying (P = 0.04). Pullet access to perches did not affect serum OC levels in 71-wk-old hens (P = 0.15). In conclusion, a chicken OC ELISA has been validated that is sensitive and accurate with adequate discriminatory power for measuring bone remodeling in chickens.

Effects of anesthesia and surgery on serial blood gas values and lactate concentrations in yellow perch (Perca flavescens), walleye pike (Sander vitreus), and koi (Cyprinus carpio).

PubMed

Hanley, Christopher S; Clyde, Victoria L; Wallace, Roberta S; Paul-Murphy, Joanne; Patterson, Tamatha A; Keuler, Nicholas S; Sladky, Kurt K

2010-05-15

OBJECTIVE-To evaluate serial blood gas values and lactate concentrations in 3 fish species undergoing surgery and to compare blood lactate concentrations between fish that survived and those that died during the short-term postoperative period. DESIGN-Prospective cohort study. Animals-10 yellow perch, 5 walleye pike, and 8 koi. PROCEDURES-Blood samples were collected from each fish at 3 time points: before anesthesia, during anesthesia, and immediately after surgery. Blood gas values and blood lactate concentrations were measured. Fish were monitored for 2 weeks postoperatively. RESULTS-All walleye and koi survived, but 2 perch died. Blood pH significantly decreased in perch from before to during anesthesia, but increased back to preanesthesia baseline values after surgery. Blood Pco(2) decreased significantly in perch from before anesthesia to immediately after surgery, and also from during anesthesia to immediately after surgery, whereas blood Pco(2) decreased significantly in koi from before to during anesthesia. Blood Po(2) increased significantly in both perch and koi from before to during anesthesia, and also in koi from before anesthesia to immediately after surgery. For all 3 species, blood lactate concentrations increased significantly from before anesthesia to immediately after surgery. Blood lactate concentration (mean +/- SD) immediately after surgery for the 8 surviving perch was 6.06 +/- 1.47 mmol/L, which was significantly lower than blood lactate concentrations in the 2 nonsurviving perch (10.58 and 10.72 mmol/L). CONCLUSIONS AND CLINICAL RELEVANCE-High blood lactate concentrations following surgery in fish may be predictive of a poor short-term postoperative survival rate.

Balancing past and present: how experience influences boldness over time in Eurasian perch

PubMed Central

Magnhagen, Carin

2017-01-01

Abstract Adapting to fluctuating predation conditions is a challenge for prey. By learning through experience, animals may adjust their anti-predator behavior to better reflect current predation risk. Although many studies show experience of predation to alter prey behavior, little is known about how prey rely on such experience over time. By comparing boldness over different temporal scales between individuals of Eurasian perch, either experienced or naïve of predators, we examine how risk is traded based on past and present experience. Differences in predator exposure during the first year of life were found to lead to differences in risk-taking behavior, even after the perch been kept in a predator-free environment for 9 months. However, the response to a potential predator was quickly readjusted after increased experience of current conditions. The results highlight how prey have to balance past experiences of predators against current threat levels. PMID:29491973

Balancing past and present: how experience influences boldness over time in Eurasian perch.

PubMed

Hellström, Gustav; Magnhagen, Carin

2017-04-01

Adapting to fluctuating predation conditions is a challenge for prey. By learning through experience, animals may adjust their anti-predator behavior to better reflect current predation risk. Although many studies show experience of predation to alter prey behavior, little is known about how prey rely on such experience over time. By comparing boldness over different temporal scales between individuals of Eurasian perch, either experienced or naïve of predators, we examine how risk is traded based on past and present experience. Differences in predator exposure during the first year of life were found to lead to differences in risk-taking behavior, even after the perch been kept in a predator-free environment for 9 months. However, the response to a potential predator was quickly readjusted after increased experience of current conditions. The results highlight how prey have to balance past experiences of predators against current threat levels.

Distribution and exploitation of Nile perch Lates niloticus in relation to stratification in Lake Victoria, East Africa

USGS Publications Warehouse

Taabu-Munyaho, A.; Kayanda, Robert J.; Everson, Inigo; Grabowski, Timothy B.; Marteinsdóttir, Gudrún

2013-01-01

Stratification restricts habitable areas forcing fish to balance between favourable temperature and minimum dissolved oxygen requirements. Acoustic surveys conducted during the stratified and isothermal periods on tropical Lake Victoria indicated that stratification of temperature and dissolved oxygen (DO) affected vertical distribution of Nile perch. There was higher mean temperature (25.6 ± 0.5 °C) and lower DO (6.4 ± 1.8 mg/l) during stratified period compared to the isothermal period (mean temperature 24.9 ± 0.3 °C; mean DO 7.3 ± 0.6 mg/l). Higher mean densities of Nile perch were recorded in the coastal (0.44 ± 0.03) and deep (0.27 ± 0.02 g/m3) strata during the stratified compared to the isothermal season (coastal: 0.24 ± 0.01; deep: 0.12 ± 0.02 g/m3). In addition, Nile perch density in the upper 0–40 m depth layers in the coastal and deep strata increased by over 50% from the isothermal to the stratified season. Daily landings from 65 motorised fishing boats between October 2008 and September 2010 show higher mean catch (26.29 ± 0.17 kg/boat/day) during stratified compared to the isothermal (23.59 ± 0.15) season. Thermal stratification apparently compresses the habitat available to Nile perch and can potentially result in higher exploitation. Managers should evaluate the potential benefits of instituting closed seasons during the stratified period, and stock assessment models should take into account the seasonal niche compression.

Effects of stocking density, light and perches on broiler growth.

PubMed

Velo, Ramón; Ceular, Angel

2017-02-01

The aim of this study was to determine the effect of stocking density, light intensity and light color on broiler growth. The experiment consisted of four 35-day phases during each of which 320 chickens were surveyed. The research was performed at stocking densities of four and six birds/m 2 . Illuminances of 15 and 30 lx were obtained through commercial lamps with 4000 K and 6000 K color temperatures. Lighting was used 17 h a day, between 06.00 and 23.00 hours (17 L:7 D). The results showed a decrease in body, carcass, breast and thighs weight (P < 0.05) with the increase in stocking density. Body weight decreased by 10.5% and carcass weight decreased by 9.4% at six birds/m 2 stocking density. Contrastingly, no differences were found for the tested light colors. Increasing illuminance from 15 to 30 lx caused a 1.9% decrease in body weight. The analysis of the effect of perches revealed that using perches significantly increased body (2.5%) and breast weight (11.8%). The interactions between light intensity or color and stocking density and between light intensity and light color were analyzed. © 2016 Japanese Society of Animal Science.

75 FR 8820 - Magnuson-Stevens Act Provisions; Fisheries Off West Coast States; Pacific Coast Groundfish...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-26

... Pacific Ocean perch) will increase slightly with the adjustments to the cumulative limits in the limited..., projected impacts to Pacific Ocean perch (POP), darkblotched rockfish, and widow rockfish are also reduced... regulatory discards, while balancing the risk of inducing effort shifts to convert the trip limit from an...

The toxic effects of ammonia exposure on antioxidant and immune responses in Rockfish, Sebastes schlegelii during thermal stress.

PubMed

Kim, Shin-Hu; Kim, Jun-Hwan; Park, Myoung-Ae; Hwang, Seong Don; Kang, Ju-Chan

2015-11-01

Rockfish, Sebastes schlegelii (mean weight 14.53 ± 1.14 cm, and mean weight 38.36 ± 3.45 g) were exposed for 4 weeks (2 weeks and 4 weeks) with the different levels of ammonia in the concentrations of 0, 0.1, 0.5, 1.0mg/L at 19 and 24°C. The ammonia exposure induced significant alterations in antioxidant responses. The activities of SOD, CAT, and GST were considerably increased by the ammonia exposure depending on water temperature, whereas the GSH level was notably decreased after 2 and 4 weeks. In the stress indicators, the cortisol and HSP 70 were significantly elevated by the exposure to ammonia depending on water temperature. In innate immune responses, the phagocytosis and lysozyme activity were notably decreased by ammonia exposure depending on water temperature after 2 and 4 weeks. The results suggest that ammonia exposure depending on water temperature can induce the considerable alterations in antioxidant responses, stress, and immune inhibition. Copyright © 2015 Elsevier B.V. All rights reserved.

Geochemistry and hydrology of perched groundwater springs: assessing elevated uranium concentrations at Pigeon Spring relative to nearby Pigeon Mine, Arizona (USA)

USGS Publications Warehouse

Beisner, Kimberly R.; Paretti, Nicholas; Tillman, Fred; Naftz, David L.; Bills, Donald; Walton-Day, Katie; Gallegos, Tanya J.

2017-01-01

The processes that affect water chemistry as the water flows from recharge areas through breccia-pipe uranium deposits in the Grand Canyon region of the southwestern United States are not well understood. Pigeon Spring had elevated uranium in 1982 (44 μg/L), compared to other perched springs (2.7–18 μg/L), prior to mining operations at the nearby Pigeon Mine. Perched groundwater springs in an area around the Pigeon Mine were sampled between 2009 and 2015 and compared with material from the Pigeon Mine to better understand the geochemistry and hydrology of the area. Two general groups of perched groundwater springs were identified from this study; one group is characterized by calcium sulfate type water, low uranium activity ratio 234U/238U (UAR) values, and a mixture of water with some component of modern water, and the other group by calcium-magnesium sulfate type water, higher UAR values, and radiocarbon ages indicating recharge on the order of several thousand years ago. Multivariate statistical principal components analysis of Pigeon Mine and spring samples indicate Cu, Pb, As, Mn, and Cd concentrations distinguished mining-related leachates from perched groundwater springs. The groundwater potentiometric surface indicates that perched groundwater at Pigeon Mine would likely flow toward the northwest away from Pigeon Spring. The geochemical analysis of the water, sediment and rock samples collected from the Snake Gulch area indicate that the elevated uranium at Pigeon Spring is likely related to a natural source of uranium upgradient from the spring and not likely related to the Pigeon Mine.

Retention of mercury in the muscle of yellow perch (Perca flavescens) and rock bass (Ambloplites rupestris)

USGS Publications Warehouse

Laarman, Percy W.; Willford, Wayne A.; Olson, James R.

1976-01-01

Mercury-contaminated yellow perch (Perca flavescens) and rock bass (Ambloplites rupestris) were collected from Lake St. Clair and stocked in two earthen ponds in September 1970. Twenty-six months later, concentrations of total mercury in the fillets had declined 53% in the yellow perch and 59% in the rock bass; however, the mean weight of the fish increased 88 and 183%, respectively, during the same period. All of the reduction in mercury concentrations was attributable to dilution by growth. Slight discrepancies between the theoretical and observed reduction of mercury concentrations suggest an initial redistribution of residues from other tissues to the muscle and a continued incorporation of background amounts of mercury during growth.

Morphological alterations in the liver of yellow perch (Perca flavescens) from a biological mercury hotspot.

PubMed

Müller, Anne-Katrin; Brinkmann, Markus; Baumann, Lisa; Stoffel, Michael H; Segner, Helmut; Kidd, Karen A; Hollert, Henner

2015-11-01

Mercury (Hg) contamination is a global issue due to its anthropogenic release, long-range transport, and deposition in remote areas. In Kejimkujik National Park and National Historic Site, Nova Scotia, Canada, high concentrations of total mercury (THg) were found in tissues of yellow perch (Perca flavescens). The aim of this study was to evaluate a possible relationship between THg concentrations and the morphology of perch liver as a main site of metal storage and toxicity. Yellow perch were sampled from five lakes known to contain fish representing a wide range in Hg concentrations in fall 2013. The ultrastructure of hepatocytes and the distribution of Hg within the liver parenchyma were analyzed by transmission electron microscopy (TEM) and electron energy loss spectrometry (EELS). The relative area of macrophage aggregates (MAs) in the liver was determined using image analysis software and fluorescence microscopy. No relation between general health indicators (Fulton's condition index) and THg was observed. In line with this, TEM examination of the liver ultrastructure revealed no prominent pathologies related to THg accumulation. However, a morphological parameter that appeared to increase with muscle THg was the relative area of MAs in the liver. The hepatic lysosomes appeared to be enlarged in samples with the highest THg concentrations. Interestingly, EELS analysis revealed that the MAs and hepatic lysosomes contained Hg.

Perched groundwater-surface interactions and their consequences in stream flow generation in a semi-arid headwater catchment

NASA Astrophysics Data System (ADS)

Molenat, Jerome; Bouteffeha, Maroua; Raclot, Damien; Bouhlila, Rachida

2013-04-01

In semi-arid headwater catchment, it is usually admitted that stream flow comes predominantly from Hortonian overland flow (infiltration excess overland flow). Consequently, subsurface flow processes, and especially perched or shallow groundwater flow, have not been studied extensively. Here we made the assumption that perched groundwater flow could play a significant role in stream flow generation in semi-arid catchment. To test this assumption, we analyzed stream flow time series of a headwater catchment in the Tunisian Cap Bon region and quantified the flow fraction coming from groundwater discharge and that from overland flow. Furthermore, the dynamics of the perched groundwater was analyzed, by focusing on the different perched groundwater-surface interaction processes : diffuse and local infiltration, diffuse exfiltration, and direct groundwater discharge to the stream channel. This work is based on the 2.6 km² Kamech catchment (Tunisia), which belongs to the long term Mediterranean hydrological observatory OMERE (Voltz and Albergel, 2002). Results show that even though Hortonian overland flow was the main hydrological process governing the stream flow generation, groundwater discharge contribution to the stream channel annually accounted for from 10% to 20 % depending on the year. Furthermore, at some periods, rising of groundwater table to the soil surface in bottom land areas provided evidences of the occurrence of saturation excess overland flow processes during some storm events. Reference Voltz , M. and Albergel , J., 2002. OMERE : Observatoire Méditerranéen de l'Environnement Rural et de l'Eau - Impact des actions anthropiques sur les transferts de masse dans les hydrosystèmes méditerranéens ruraux. Proposition d'Observatoire de Recherche en Environnement, Ministère de la Recherche.

Status and prospects for the yellow perch genetic improvement program in Milwaukee, Wisconsin

USDA-ARS?s Scientific Manuscript database

In 2004, a broodstock improvement program was initiated with the aim of developing defined geographic strains of yellow perch that have been selected for improved growth. Following a survey of 19 populations ranging from the Mid-West to the Eastern coast of the United States, and subsequent efforts ...

50 CFR 679.64 - Harvesting sideboard limits in other fisheries.

Code of Federal Regulations, 2010 CFR

2010-10-01

.../processors be calculated? Except for Aleutian Islands pollock and BSAI Pacific cod, the Regional... group in which a TAC is specified for an area or subarea of the BSAI as follows: (i) Aleutian Islands Pacific ocean perch. (A) The Aleutian Islands Pacific ocean perch harvest limit will be equal to the 1996...

Reappraising factors affecting mourning dove perch coos

USGS Publications Warehouse

Sayre, M.W.; Atkinson, R.D.; Baskett, T.S.; Haas, G.H.

1978-01-01

Results confirmed pairing as the primary factor influencing perch-cooing rates of wild mourning doves (Zenaida macroura). Marked unmated males cooed at substantially higher rates (6.2x) than mated males, had greater probability of cooing (2.3x) during 3-minute periods, and continued cooing longer each morning than mated males. Population density was not a major factor affecting cooing. Unmated males cooed more frequently in the presence of other cooing doves (P < 0.05) than when alone, but the number of additional doves above 1 was unimportant. Cooing rates of both mated and unmated males on areas with dissimilar dove densities were not significantly different. Within limits of standard call-count procedure, weather exerted no detectable influence on cooing.

Do water level fluctuations influence production of walleye and yellow perch young-of-the-year in large northern lakes?

USGS Publications Warehouse

Larson, James H.; Staples, David F.; Maki, Ryan P.; Vallazza, Jon M.; Knights, Brent C.; Peterson, Kevin E.

2016-01-01

Many ecological processes depend on the regular rise and fall of water levels (WLs), and artificial manipulations to WL regimes can impair important ecosystem services. Previous research has suggested that differences in WL between late summer and early spring may alter the suitability of shoals used by Walleyes Sander vitreus for spawning. Other species, such as the Yellow Perch Perca flavescens, are unlikely to be affected in the same way by WL fluctuations because their spawning requirements are quite different. We used 11–23 years of data from six northern Minnesota lakes to assess the effects of WL fluctuations on the abundances of young-of-the-year (age-0) Walleyes and Yellow Perch. In two lakes (Rainy Lake and Lake Kabetogama), a change in WL management occurred in 2000, after which these lakes saw increased age-0 Walleye abundance, while the other study lakes experienced decreases or no change. Rainy Lake and Lake Kabetogama also had increases in age-0 Yellow Perch, but another study lake did also. We used partial least-squares regression to assess whether WL metrics were associated with variation in age-0 Walleye and Yellow Perch abundances, but WL metrics were seldom associated with age-0 abundance for either species. Our analysis suggested a potential influence of WL regulation on age-0 Walleye abundance, but we found no evidence that early spring access to spawning shoals was the mechanism by which this occurred.

A Red-Tailed Hawk perches on a stump at KSC.

NASA Technical Reports Server (NTRS)

2000-01-01

Near a road at Kennedy Space Center, a red-tailed hawk perches on a weathered tree stump. The red-tailed hawk has a stocky build and broad, rounded wings. Its broad range covers Alaska and Nova Scotia south to Panama. It can frequently be seen perched in a tree at the edge of a meadow, watching for movement in the grass below. It feeds mainly on small rodents. The Refuge encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects. Kennedy Space Center shares a boundary with the Merritt Island National Wildlife Refuge, encompassing 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

76 FR 30308 - Pacific Fishery Management Council; Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-25

... Stock Assessment Review Panel (STAR Panel) for the Pacific ocean perch and petrale sole stock assessments will hold a work session that is open to the public. DATES: The STAR Panel for Pacific ocean perch... 5:30 p.m. or as necessary to complete business for the day. The STAR panel will reconvene on Tuesday...

Effects of fasting, temperature, and photoperiod on preproghrelin mRNA expression in Chinese perch.

PubMed

Song, Yi; Zhao, Cheng; Liang, Xu-Fang; He, Shan; Tian, Changxu; Cheng, Xiaoyan; Yuan, Xiaochen; Lv, Liyuan; Guo, Wenjie; Xue, Min; Tao, Ya-Xiong

2017-06-01

Preproghrelin, a gut/brain peptide, plays an important role in the regulation of food intake and energy homeostasis in teleost and mammals. In the present study, we obtained the full-length preproghrelin cDNA in Chinese perch. The preproghrelin messenger RNA (mRNA) tissue expression showed that level was much higher in stomach and pituitary than in other tissues. The fasting study showed, after gastric emptying (3-6 h), short-term fasting (6-12 h) increased preproghrelin expression in the stomach. While in the pituitary, fasting reduced preproghrelin expression at 1, 3, 12, and 48 h, presenting state fluctuation of self-adjustment. The temperature study showed that the mRNA expression of preproghrelin was the highest in the brain at 26 °C and highest in the stomach at 32 °C, respectively, with different optimum temperature in these two tissues, reflecting spatiotemporal differences of regulation by central nervous system and peripheral organs. The photoperiod study showed that normal light (11 h of lightness and 13 h of darkness) led to highest preproghrelin expression, both in the brain and in the stomach, than continuous light or continuous dark, proving food intake is adapted to natural photoperiod or normal light in this study. These results all indicated that tissue-specific preproghrelin expression of Chinese perch could be significantly affected by environmental factors. Short-term fasting of 6 h after gastric emptying, 26 °C, and normal light led to higher preproghrelin expression, which indicated potential appetite increase in Chinese perch.

Concentrations of 17 elements in the zebra mussel (Dreissena polymorpha), in different tissues of perch (Perca fluviatilis), and in perch intestinal parasites (Acanthocephalus lucii) from the subalpine lake Mondsee, Austria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sures, B.; Steiner, W.; Rydlo, M.

1999-11-01

Concentrations of the elements Al, Ag, Ba, ca, Cd, Co, Cr, cu, Fe, Ga, Mg, Mn, Ni, Pb, Sr, Tl, and Zn were analyzed by inductively coupled plasma mass spectrometry in the acanthocephalan Acanthocephalus lucii (Mueller); in its host, Perca fluviatilis (L.), and in the soft tissue of the zebra mussel, Dreissena polymorpha (Pallas). All animals were collected from the same sampling site in a subalpine lake, Mondsee, in Austria. Most of the elements were found at significantly higher concentrations in the acanthocephalan than in different tissues (muscle, liver, and intestinal wall) of its perch host. Only Co was concentratedmore » in the liver of perch to a level that was significantly higher than that found in the parasite. Most of the analyzed elements were also present at significantly higher concentrations in A. lucii than in D. polymorpha. Barium and Cr were the only elements recorded at higher concentrations in the mussel compared with the acanthocephalan. Thus, when comparing the accumulation of elements, the acanthocephalans appear to be even more suitable than the zebra mussels in terms of their use in the detection of metal contamination within aquatic biotopes. Spearman correlation analysis revealed that the concentrations of several elements within the parasites decreased with increasing infrapopulation. Furthermore, the levels of some elements in the perch liver were negatively correlated with the weight of A. lucii in the intestine. Thus, it emerged that not only is there competition for elements between acanthocephalans inside the gut but there is also competition for these elements between the host and the parasites. The elevated element concentrations demonstrated here in the parasitic worm A. lucii provide support for further investigations of these common helminthes and of their accumulation properties.« less

Retention of mercury in the muscle of yellow perch (Perca flavescens) and rock bass (Ambloplites rupestris)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laarman, P.W.; Willford, W.A.; Olson, J.R.

1976-03-01

Mercury-contaminated yellow perch (Perca flavescens) and rock bass (Ambloplites rupestris) were collected from Lake St. Clair and stocked in two earthern ponds in September 1970. Twenty-six months later, concentrations of total mercury in the fillets had declined 53 percent in the yellow perch and 59 percent in the rock bass; however, the mean weight of the fish increased 88 and 183 percent, respectively, during the same period. All of the reduction in mercury concentrations was attributable to dilution by growth. Slight discrepancies between the theoretical and observed reduction of mercury concentrations suggest an initial redistribution of residues from other tissuesmore » to the muscle and a continued incorporation of background amounts of mercury during growth.« less

A kingfisher perches on a branch

NASA Technical Reports Server (NTRS)

1999-01-01

A belted kingfisher perches on a twig in the Merritt Island National Wildlife Refuge, which shares a boundary with the Kennedy Space Center. The pigeon-sized, blue-gray male is identified by the blue-gray breast band; females show a chestnut belly band. The belted kingfisher ranges throughout the United States and Canada, wintering south to Panama and the West Indies. They dive into the water for fish and may also take crabs, crayfish, salamanders, lizards, mice and insects. The 92,000-acre refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

Comparison of nutritional quality in fish maw product of croaker Protonibea diacanthus and perch Lates niloticus

NASA Astrophysics Data System (ADS)

Wen, Jing; Zeng, Ling; Chen, Ziming; Xu, Youhou

2016-08-01

Fish maw (the dried swimbladders of fish) is ranked in the list of the four sea treasures in Chinese cuisine. Fish maw is mainly produced from croaker, which is the most highly priced. However, some of the fish maw being sold as croaker maw are in fact not from croaker, but from the Nile perch Lates niloticus. The present work determined and compared the proximate composition, amino acid and fatty acid composition of croaker Protonibea diacanthus maw and perch L. niloticus maw. The results indicated that both maws were high protein sources and low in fat content. The dominant amino acids in both maws were glycine, proline, glutamic acid, alanine and arginine. These amino acids constituted 66.2% and 66.4% of the total amino acids in P. diacanthus and L. niloticus, respectively. The ratio of FAA: TAA (functional amino acids: total amino acids) in both maws were 0.69. This is a good explanation for why fish maws have been widely utilized as a traditional tonic and remedy in Asia. Except valine and histidine, all the essential amino acid contents in P. diacanthus were higher than in L. niloticus. Moreover, croaker P. diacanthus maw contained more AA and DHA than perch L. niloticus maw, showing a higher ratio of n-3 / n-6, which is more desirable.

Approaches to the simulation of unconfined flow and perched groundwater flow in MODFLOW

USGS Publications Warehouse

Bedekar, Vivek; Niswonger, Richard G.; Kipp, Kenneth; Panday, Sorab; Tonkin, Matthew

2012-01-01

Various approaches have been proposed to manage the nonlinearities associated with the unconfined flow equation and to simulate perched groundwater conditions using the MODFLOW family of codes. The approaches comprise a variety of numerical techniques to prevent dry cells from becoming inactive and to achieve a stable solution focused on formulations of the unconfined, partially-saturated, groundwater flow equation. Keeping dry cells active avoids a discontinuous head solution which in turn improves the effectiveness of parameter estimation software that relies on continuous derivatives. Most approaches implement an upstream weighting of intercell conductance and Newton-Raphson linearization to obtain robust convergence. In this study, several published approaches were implemented in a stepwise manner into MODFLOW for comparative analysis. First, a comparative analysis of the methods is presented using synthetic examples that create convergence issues or difficulty in handling perched conditions with the more common dry-cell simulation capabilities of MODFLOW. Next, a field-scale three-dimensional simulation is presented to examine the stability and performance of the discussed approaches in larger, practical, simulation settings.

An avirulent Micropterus salmoides rhabdovirus vaccine candidate protects Chinese perch against rhabdovirus infection.

PubMed

Lijuan, Zhang; Ningqiu, Li; Qiang, Lin; Lihui, Liu; Hongru, Liang; Zhibin, Huang; Xiaozhe, Fu

2018-06-01

In order to develop live vaccine against Siniperca chuatsi rhabdovirus (SCRV) disease, an avirulent virus strain, designed as Micropterus salmoides rhabdovirus Sanshui (MSRV-SS), was selected from six fish rhabdovirus isolates (SCRV-QY、SCRV-SS、SCRV-GM、CMRV-FS、OMBRV-JM、MSRV-SS) by fish challenge assay. When Chinese perch (Siniperca chuatsi) were intraperitoneally injected live virus strain MSRV-SS, they were completely protected from virulent SCRV-GM challenge with a relative percent survival (RPS) of 100% on 18th day post vaccination. Then, the wild type MSRV-SS was purified by plaque clone assays, and the biological characteristics of the clonal strain designed as MSRV-SS-7 were investigated. The MSRV-SS-7 was avirulent to Chinese perch and its growth characteristic was similar to the MSRV-SS. The immune protection effects of clonal MSRV-SS-7 against virulent SCRV-GM were evaluated by intraperitoneal injection (IP) vaccination and immersion (IM) vaccination, their RPSs were all 100%. Altogether, these results indicate that MSRV-SS-7 is a potential live vaccine candidate against SCRV disease. Copyright © 2018 Elsevier Ltd. All rights reserved.

CO2-induced ocean acidification increases anxiety in Rockfish via alteration of GABAA receptor functioning

PubMed Central

Hamilton, Trevor James; Holcombe, Adam; Tresguerres, Martin

2014-01-01

The average surface pH of the ocean is dropping at a rapid rate due to the dissolution of anthropogenic CO2, raising concerns for marine life. Additionally, some coastal areas periodically experience upwelling of CO2-enriched water with reduced pH. Previous research has demonstrated ocean acidification (OA)-induced changes in behavioural and sensory systems including olfaction, which is due to altered function of neural gamma-aminobutyric acid type A (GABAA) receptors. Here, we used a camera-based tracking software system to examine whether OA-dependent changes in GABAA receptors affect anxiety in juvenile Californian rockfish (Sebastes diploproa). Anxiety was estimated using behavioural tests that measure light/dark preference (scototaxis) and proximity to an object. After one week in OA conditions projected for the next century in the California shore (1125 ± 100 µatm, pH 7.75), anxiety was significantly increased relative to controls (483 ± 40 µatm CO2, pH 8.1). The GABAA-receptor agonist muscimol, but not the antagonist gabazine, caused a significant increase in anxiety consistent with altered Cl− flux in OA-exposed fish. OA-exposed fish remained more anxious even after 7 days back in control seawater; however, they resumed their normal behaviour by day 12. These results show that OA could severely alter rockfish behaviour; however, this effect is reversible. PMID:24285203

CO2-induced ocean acidification increases anxiety in rockfish via alteration of GABAA receptor functioning.

PubMed

Hamilton, Trevor James; Holcombe, Adam; Tresguerres, Martin

2014-01-22

The average surface pH of the ocean is dropping at a rapid rate due to the dissolution of anthropogenic CO2, raising concerns for marine life. Additionally, some coastal areas periodically experience upwelling of CO2-enriched water with reduced pH. Previous research has demonstrated ocean acidification (OA)-induced changes in behavioural and sensory systems including olfaction, which is due to altered function of neural gamma-aminobutyric acid type A (GABAA) receptors. Here, we used a camera-based tracking software system to examine whether OA-dependent changes in GABAA receptors affect anxiety in juvenile Californian rockfish (Sebastes diploproa). Anxiety was estimated using behavioural tests that measure light/dark preference (scototaxis) and proximity to an object. After one week in OA conditions projected for the next century in the California shore (1125 ± 100 µatm, pH 7.75), anxiety was significantly increased relative to controls (483 ± 40 µatm CO2, pH 8.1). The GABAA-receptor agonist muscimol, but not the antagonist gabazine, caused a significant increase in anxiety consistent with altered Cl(-) flux in OA-exposed fish. OA-exposed fish remained more anxious even after 7 days back in control seawater; however, they resumed their normal behaviour by day 12. These results show that OA could severely alter rockfish behaviour; however, this effect is reversible.

Evaluation of daily creel and minimum length limits for Black Crappies and Yellow Perch in Wisconsin

USGS Publications Warehouse

Mosel, Kyle; Isermann, Daniel A.; Hansen, Jonathan F.

2015-01-01

Harvest regulations for Black Crappie Pomoxis nigromaculatus and Yellow Perch Perca flavescens in the northern USA and Canada have not been thoroughly evaluated, and specific guidance regarding where minimum length limits (MLLs) might improve these fisheries is lacking. We examined whether: (1) transitioning from an aggregate statewide daily creel limit of 25 panfish to species-specific daily creel limits of <25 fish or implementing statewide MLLs could reduce harvest of Black Crappie and Yellow Perch in Wisconsin by ≥25%, and (2) MLLs would improve yield by ≥10% and mean TL of harvested fish by ≥25 mm in Wisconsin fisheries. Creel surveys indicated that ≥94% of Wisconsin anglers did not harvest a Black Crappie or Yellow Perch, and ≤0.12% of anglers harvested a daily creel limit of 25 fish. Daily creel limits would need to be ≤7 fish/ angler to reduce harvest by ≥25%. Statewide MLLs would need to be ≥229 mm for Black Crappie and ≥203 mm for Yellow Perch to reduce harvest by ≥25%, but predicted responses to MLLs varied among simulated populations. In general, MLLs were not predicted to improve yield, indicating that growth overfishing was not a widespread problem. Minimum length limits could improve mean TL of harvested fish, but increases ≥25 mm were only observed under 254-mm and 279-mm MLLs, and anglers would have to accept predicted reductions in harvest of ≥30% to achieve these improvements. A 229-mm MLL offered a more equitable trade-off between increases in mean TLs of harvested fish (11–21-mm improvements) and reductions in harvest (22–37% reductions). Our modeling provides a framework for managers to make more informed decisions regarding harvest regulations, but more information regarding angler preferences is needed for selecting appropriate management objectives and harvest regulations.

Extraction and Production of Omega-3 from UniMAP Puyu (Jade Perch) and Mackarel

NASA Astrophysics Data System (ADS)

Nur Izzati, I.; Zainab, H.; Nornadhiratulhusna, M.; Chee Hann, Y.; Khairunissa Syairah, A. S.; Amira Farzana, S.

2018-03-01

Extraction techniques to extract fish oil from various types of fish are numerous but not widely accepted because of the use of chemicals that may be harmful to health. In this study, fish oil is extracted using a technique of Microwave-Assisted Extraction, which uses only water. The optimum conditions required for the production of fish oil for extraction is carried out by examining three parameters such as microwave power (300-700W), extraction time (10-30 min) and amount of water used (70-190ml). Optimum conditions were determined after using design of experiments (DOE). The optimum condition obtained was 300 W for microwave power, 10 minutes extraction time and 190 milliliter amounts of water used. Fourier transform infrared spectroscopy (FTIR) was used to analyze the functional groups of fish oil. Two types of fish such as Jade Perch or UniMAP Puyu and Indian Mackerel were used. A standard omega-3 oil sample (Blackmores) purchased from pharmacy was also determined to confirm the presence of omega-3 oil in these fishes. Similar compounds were present in Jade Perch and Indian Mackerel as compared to the standard. Therefore, there were presence of omega-3 fish oil in the two types of fish. From this study, omega-3 in UniMAP Puyu fish was higher compared to Indian Mackerel fish. However, based on the FTIR analysis, besides the presence of omega-3, the two fishes also contain other functional groups such as alkanes, alkenes, aldehyde, ketones and many others. The yield of fish oil for the Jade Perch was low compared to Indian Mackerel which was 9% while Indian Mackerel was 10 %.

Cooled perch effects on performance and well-being traits in caged White Leghorn hens

USDA-ARS?s Scientific Manuscript database

We assessed the effects of chilled water cooling perches on hen performance, feather condition, foot health, and physiological and behavioral parameters during the 2013 summer with a 4-h acute heating episode. White Leghorn pullets at 16 wk of age were randomly assigned to 18 cages arranged into 3 b...

Toxic effects on bioaccumulation and hematological parameters of juvenile rockfish Sebastes schlegelii exposed to dietary lead (Pb) and ascorbic acid.

PubMed

Kim, Jun-Hwan; Kang, Ju-Chan

2017-06-01

Juvenile rockfish, Sebastes schlegelii (mean length 11.3 ± 1.2 cm, and mean weight 32.5 ± 4.1 g) were exposed for four weeks to dietary lead (Pb 2+ ) at 0, 120, and 240 mg/L and ascorbic acid (AsA) at 100, 200, and 400 mg/L. The exposure concentrations and duration of significant Pb-induced accumulations in specific tissues of S. schlegelii were assessed. High levels of ascorbic acid significantly attenuated accumulations following exposure to dietary Pb. Dietary Pb exposure caused a significant increase in blood Pb concentrations, whereas red blood cell (RBC) count, hematocrit, and hemoglobin were significantly decreased. Notable changes were also observed in plasma calcium, magnesium, glucose, cholesterol, glutamic oxaloacetic transaminase (GOT), and glutamic pyruvate transaminase (GPT). The growth performance of S. schlegelii was significantly decreased. High doses AsA supplemention were effective in attenuating the changes brought about by dietary Pb exposure. Copyright © 2017 Elsevier Ltd. All rights reserved.

Myxobolus neurophilus: a common myxosporidian parasite infecting yellow perch Perca flavacens (Mitchell) in Saskatchewan, Canada

USDA-ARS?s Scientific Manuscript database

The goal of this study was to identify a myxosporidian parasite infecting the central nervous system of yellow perch Perca flavacens (Mitchell) observed while investigating a fish kill in Saskatchewan, Canada. Fish were collected from seven different lakes, from 2 distinct watersheds. Sixty-four p...

Age, growth, spawning season, and fecundity of the trout-perch (Percopsis omiscomaycus) in southeastern Lake Michigan

USGS Publications Warehouse

House, Robert; Wells, LaRue

1973-01-01

Growth of trout-perch (Percopsis omiscomaycus) in the first 2 years of life was somewhat slower in southeastern Lake Michigan (average length at end of second year, 83 mm) than in Lower Red Lake, Minnesota (90 mm), but considerably faster than in Lake Superior (58 mm); size differences in later years were slightly less pronounced. Young fish began growing earlier in the year (some before June 20) than older ones (as late as August). Females tended to live longer than males, as they do in Lower Red Lake and Lake Superior. Trout-perch spawned from late June or early July until late September, somewhat later than in Lower Red Lake (May to August) or Lake Erie (June to August). Fecundity was similar to that in Lake Erie; mature females 94-146 mm long contained from 126 to 1329 yolked eggs.

Molecular Evidence for Association of Chlamydiales Bacteria with Epitheliocystis in Leafy Seadragon (Phycodurus eques), Silver Perch (Bidyanus bidyanus), and Barramundi (Lates calcarifer)

PubMed Central

Meijer, Adam; Roholl, Paul J. M.; Ossewaarde , Jacobus M.; Jones, Brian; Nowak, Barbara F.

2006-01-01

Epitheliocystis in leafy seadragon (Phycodurus eques), silver perch (Bidyanus bidyanus), and barramundi (Lates calcarifer), previously associated with chlamydial bacterial infection using ultrastructural analysis, was further investigated by using molecular and immunocytochemical methods. Morphologically, all three species showed epitheliocystis cysts in the gills, and barramundi also showed lymphocystis cysts in the skin. From gill cysts of all three species and from skin cysts of barramundi 16S rRNA gene fragments were amplified by PCR and sequenced, which clustered by phylogenetic analysis together with other chlamydia-like organisms in the order Chlamydiales in a lineage separate from the family Chlamydiaceae. By using in situ RNA hybridization, 16S rRNA Chlamydiales-specific sequences were detected in gill cysts of silver perch and in gill and skin cysts of barramundi. By applying immunocytochemistry, chlamydial antigens (lipopolysaccharide and/or membrane protein) were detected in gill cysts of leafy seadragon and in gill and skin cysts of barramundi, but not in gill cysts of silver perch. In conclusion, this is the first time epitheliocystis agents of leafy seadragon, silver perch and barramundi have been undoubtedly identified as belonging to bacteria of the order Chlamydiales by molecular methods. In addition, the results suggested that lymphocystis cysts, known to be caused by iridovirus infection, could be coinfected with the epitheliocystis agent. PMID:16391055

Sedimentary patterns in perched spring travertines near Granada (Spain) as indicators of the paleohydrological and paleoclimatological evolution of a karst massif

NASA Astrophysics Data System (ADS)

Martín-Algarra, Agustín.; Martín-Martín, Manuel; Andreo, Bartolomé; Julià, Ramón; González-Gómez, Cecilio

2003-10-01

Perched spring travertines of the Granada basin (South Spain) constitute a perched system with four well-defined steps, which are formed by several facies associations deposited in different sub-environments (travertine pools, dams and cascades). These perched travertines are considered as a freshwater reef system with a facies zonation and stratigraphic architecture closely resembling that of marine reef terraces and prograding carbonate platforms. The travertine deposits have been dated by 230Th/ 234U and 14C methods. As in other Mediterranean areas, the travertine deposition occurred episodically during warm and wet interglacial periods coinciding with isotopic stages 9, 7 and 5, and with the transition between isotopic stages 2/1. During these periods, underground dissolution, large outflow in the springs and subsequent calcium carbonate precipitation occurred. In the same way that evolution of reef systems indicates sea level changes, the geomorphology, age and architecture of perched spring travertine systems may be used to interpret former climatically controlled changes in outflow, in base level marked by the altitude of springs and in the chemistry of spring waters. Thus, aggradation or climbing progradation may indicate an increase of outflow at the spring, progradation with toplap is due to a stable base level and, conversely, dowlapping progradation may signify that the base level was gradually dropping. Therefore, the travertines can be considered semiquantitative indicators of the paleohydrological evolution of karstic massifs and used as an important terrestrial proxy climate record.

Hanging out at the airport: Unusual upside-down perching behavior by Eurasian Jackdaws (Corvus monedula) in a human-dominated environment

USGS Publications Warehouse

Katzner, Todd E.

2016-01-01

Animals occupying human-dominated environments show the capacity for behavioral flexibility. Corvids are among the most intelligent synanthropic bird species. During a layover at Schipol Airport in Amsterdam, Netherlands, I photographically documented Eurasian Jackdaws (Corvus monedula) perching upside down from a building cornice. In contrast to other reports of hanging birds, these jackdaws did not forage or play while upside down and appeared to use the perching spot to observe their surroundings. Although Corvids and Psittacines are known to hang upside down, especially in captive situations, such behaviors are rarely documented in the wild, and never before in association with human-built structures.

Relative importance of perch and facilitative effects on nucleation in tropical woodland in Malawi

NASA Astrophysics Data System (ADS)

Fujita, Tomohiro

2016-01-01

Individual trees in open vegetation such as woodlands can act as "nuclei" for the colonization of forest tree species, which consequently lead to the formation of forest patches. This phenomenon is known as nucleation. The mechanism of nucleation is generally attributed to two factors: trees provide perches for frugivores that increase seed deposition (perch effect), and tree crowns ameliorate environmental conditions, which improves seedling establishment (facilitative effect). Few studies have attempted to distinguish the relative importance of these two factors. In this study, I separated these two effects in a woodland in northern Malawi. I chose Ficus natalensis as a potential nuclei tree because large individuals of this species are commonly located at the center of forest patches within open woodland at the study site. I monitored several environmental variables, seedling survival, seedling composition, and seed rain at three microsites: under F. natalensis, under Brachystegia floribunda (a dominant woodland species), and in open sites. Both tree species provided similar favorable conditions for the establishment of forest species compared to open sites. Thus, the survival of forest tree seedlings under F. natalensis and B. floribunda was similar, and substantially higher than seedling survival in open sites. However, communities of naturally occurring seedlings differed significantly between F. natalensis and B. floribunda. These results indicate that the facilitative effect alone cannot explain the nucleation pattern. I attribute this result to the perch effect of F. natalensis because the forest seedling species recorded under F. natalensis reportedly have small, brightly colored diaspores, which are indicative of dispersal by birds. Seed deposition of forest species under F. natalensis was significantly higher than that under B. floribunda or in open sites. My findings reinforce the idea that trees will lead to nucleation when they enhance seed

Developmental expression and estrogen responses of endocrine genes in juvenile yellow perch (Perca flavescens)

USDA-ARS?s Scientific Manuscript database

The present study examines the expression of growth-regulating genes (gh, prl, smtl and igf1b), the estrogen receptors (esr1 and esr2a) and aromatase (cyp19a1a) in developing yellow perch. To gain an initial understanding into the endocrine control of growth preceding and involved with sexual size d...

Nourishment of perched sand dunes and the issue of erosion control in the Great Lakes

NASA Astrophysics Data System (ADS)

Marsh, William M.

1990-09-01

Although limited in coverage, perched sand dunes situated on high coastal bluffs are considered the most prized of Great Lakes dunes. Grand Sable Dunes on Lake Superior and Sleeping Bear Dunes on Lake Michigan are featured attractions of national lakeshores under National Park Service management. The source of sand for perched dunes is the high bluff along their lakeward edge. As onshore wind crosses the bluff, flow is accelerated upslope, resulting in greatly elevated levels of wind stress over the slope brow. On barren, sandy bluffs, wind erosion is concentrated in the brow zone, and for the Grand Sable Bluff, it averaged 1 m3/yr per linear meter along the highest sections for the period 1973 1983. This mechanism accounts for about 6,500 m3 of sand nourishment to the dunefield annually and clearly has been the predominant mechanism for the long-term development of the dunefield. However, wind erosion and dune nourishment are possible only where the bluff is denuded of plant cover by mass movements and related processes induced by wave erosion. In the Great Lakes, wave erosion and bluff retreat vary with lake levels; the nourishment of perched dunes is favored by high levels. Lake levels have been relatively high for the past 50 years, and shore erosion has become a major environmental issue leading property owners and politicians to support lake-level regulation. Trimming high water levels could reduce geomorphic activity on high bluffs and affect dune nourishment rates. Locally, nourishment also may be influenced by sediment accumulation associated with harbor protection facilities and by planting programs aimed at stabilizing dunes.

Influence of mineral supplementation on growth in yellow perch Perca flavescens fed a soy-based diet

USDA-ARS?s Scientific Manuscript database

Little is known of the nutritional requirements for the growth of yellow perch in intensive aquaculture. Consequently, commercial feed formulations are based on nutritional requirements for rainbow trout, containing large quantities of fish meal and oil which are not optimal for other species. Plant...

Application of HEC-RAS for flood forecasting in perched river-A case study of hilly region, China

NASA Astrophysics Data System (ADS)

Sun, Pingping; Wang, Shuqian; Gan, Hong; Liu, Bin; Jia, Ling

2017-04-01

Flooding in small and medium rivers are seriously threatening the safety of human beings’ life and property. The simulation forecasting of the river flood and bank risk in hilly region has gradually become a hotspot. At present, there are few studies on the simulation of hilly perched river, especially in the case of lacking section flow data. And the method of how to determine the position of the levee breach along the river bank is not much enough. Based on the characteristics of the sections in hilly perched river, an attempt is applied in this paper which establishes the correlation between the flow profile computed by HEC-RAS model and the river bank. A hilly perched river in Lingshi County, Shanxi Province of China, is taken as the study object, the levee breach positions along the bank are simulated under four different design storm. The results show that the flood control standard of upper reach is high, which can withstand the design storm of 100 years. The current standard of lower reach is low, which is the flooding channel with high frequency. As the standard of current channel between the 2rd and the 11th section is low, levee along that channel of the river bank is considered to be heighten and reinforced. The study results can provide some technical support for flood proofing in hilly region and some reference for the reinforcement of river bank.

50 CFR Table 11 to Part 679 - BSAI Retainable Percentages

Code of Federal Regulations, 2014 CFR

2014-10-01

... 15 20 2 20 141 Pacific Ocean perch 20 20 20 20 35 35 20 20 20 20 35 15 7 15 20 2 20 152/151... at § 679.2, except for Pacific ocean perch; and northern, shortraker, and rougheye rockfish. 4 The... Squid Aggregatedforage fish 7 Otherspecies 4 110 Pacific cod 20 na 5 20 20 35 35 20 20 20 20 1 1 2 5 20...

50 CFR Table 11 to Part 679 - BSAI Retainable Percentages

Code of Federal Regulations, 2013 CFR

2013-10-01

... 15 20 2 20 141 Pacific Ocean perch 20 20 20 20 35 35 20 20 20 20 35 15 7 15 20 2 20 152/151... at § 679.2, except for Pacific ocean perch; and northern, shortraker, and rougheye rockfish. 4 The... Squid Aggregatedforage fish 7 Otherspecies 4 110 Pacific cod 20 na 5 20 20 35 35 20 20 20 20 1 1 2 5 20...

Isolation and expression analysis of FTZ-F1 encoding gene of black rock fish ( Sebastes schlegelii)

NASA Astrophysics Data System (ADS)

Shafi, Muhammad; Wang, Yanan; Zhou, Xiaosu; Ma, Liman; Muhammad, Faiz; Qi, Jie; Zhang, Quanqi

2013-03-01

Sex related FTZ-F1 is a transcriptional factor regulating the expression of fushi tarazu (a member of the orphan nuclear receptors) gene. In this study, FTZ-F1 gene ( FTZ-F1) was isolated from the testis of black rockfish ( Sebastes schlegeli) by homology cloning. The full-length cDNA of S. schlegeli FTZ-F1 ( ssFTZ-F1) contained a 232bp 5' UTR, a 1449bp ORF encoding FTZ-F1 (482 amino acid residules in length) with an estimated molecular weight of 5.4kD and a 105bp 3' UTR. Sequence, tissue distribution and phylogenic analysis showed that ssFTZ-F1 belonged to FTZ group, holding highly conserved regions including I, II and III FTZ-F1 boxes and an AF-2 hexamer. Relatively high expression was observed at different larva stages. In juveniles (105 days old), the transcript of ssFTZ-F1 can be detected in all tissues and the abuncance of the gene transcript in testis, ovary, spleen and brain was higher than that in other tissues. In mature fish, the abundance of gene transcript was higher in testis, ovary, spleen and brain than that in liver (trace amount), and the gene was not transcribed in other tissues. The highest abundance of gene transcript was always observed in gonads of both juvenile and mature fish. In addition, the abundance of gene transcript in male tissues were higher than that in female tissue counterparts ( P<0.05).

Space use by 4 strains of laying hens to perch, wing flap, dust bathe, stand and lie down.

PubMed

Riddle, Elizabeth R; Ali, Ahmed B A; Campbell, Dana L M; Siegford, Janice M

2018-01-01

The laying hen industry is implementing aviary systems intended to improve welfare by providing hens with more space and resources to perform species-specific behaviors. To date, limited research has examined spatial requirements of various strains of laying hens for performing key behaviors and none has been conducted within an alternative housing system. This study investigated the amount of space used by 4 strains of laying hens (Hy-Line Brown [HB], Bovans Brown [BB], DeKalb White [DW], and Hy-Line W36) to perform 5 different behaviors in the litter area of a commercial-style aviary. Hens were recorded standing [S], lying [L], perching [P], wing flapping [WF], and dust bathing [DB] on an open-litter area with an outer perch between 12:00 and 15:00 at peak lay (28 wk of age). Still images of each behavior were analyzed using ImageJ software for 16 hens per strain, and maximum hen length and width were used to calculate total area occupied per hen for each behavior. Brown hens required, on average, 89.6cm2 more space for S (P≤0.021) and 81.5cm2 more space for L (P≤0.013) than white hens. White hens used, on average, 572cm2 more space to perform WF than brown hens (P≤0.024) while brown hens used 170.3cm2 more space for DB than white hens (P≤0.022). On average, hens of all strains were wider while perching than the 15cm commonly recommended per hen (e.g., DW: 18.03; HB: 21.89cm), and brown hens required, on average, 3.38cm more space while perching than white hens (P≤0.01). Brown and white hens occupy different amounts of space when performing key behaviors. These differences, along with factors such as behavioral synchrony, clustering, and preferred inter-bird distances associated with these behaviors, should be considered when creating industry guidelines, crafting legislation and designing and stocking laying hen facilities to ensure hens can fulfill their behavioral needs.

Space use by 4 strains of laying hens to perch, wing flap, dust bathe, stand and lie down

PubMed Central

Campbell, Dana L. M.

2018-01-01

The laying hen industry is implementing aviary systems intended to improve welfare by providing hens with more space and resources to perform species-specific behaviors. To date, limited research has examined spatial requirements of various strains of laying hens for performing key behaviors and none has been conducted within an alternative housing system. This study investigated the amount of space used by 4 strains of laying hens (Hy-Line Brown [HB], Bovans Brown [BB], DeKalb White [DW], and Hy-Line W36) to perform 5 different behaviors in the litter area of a commercial-style aviary. Hens were recorded standing [S], lying [L], perching [P], wing flapping [WF], and dust bathing [DB] on an open-litter area with an outer perch between 12:00 and 15:00 at peak lay (28 wk of age). Still images of each behavior were analyzed using ImageJ software for 16 hens per strain, and maximum hen length and width were used to calculate total area occupied per hen for each behavior. Brown hens required, on average, 89.6cm2 more space for S (P≤0.021) and 81.5cm2 more space for L (P≤0.013) than white hens. White hens used, on average, 572cm2 more space to perform WF than brown hens (P≤0.024) while brown hens used 170.3cm2 more space for DB than white hens (P≤0.022). On average, hens of all strains were wider while perching than the 15cm commonly recommended per hen (e.g., DW: 18.03; HB: 21.89cm), and brown hens required, on average, 3.38cm more space while perching than white hens (P≤0.01). Brown and white hens occupy different amounts of space when performing key behaviors. These differences, along with factors such as behavioral synchrony, clustering, and preferred inter-bird distances associated with these behaviors, should be considered when creating industry guidelines, crafting legislation and designing and stocking laying hen facilities to ensure hens can fulfill their behavioral needs. PMID:29304059

Welfare of organic laying hens kept at different indoor stocking densities in a multi-tier aviary system. II: live weight, health measures and perching.

PubMed

Steenfeldt, S; Nielsen, B L

2015-09-01

Multi-tier aviary systems, where conveyor belts below the tiers remove the manure at regular intervals, are becoming more common in organic egg production. The area on the tiers can be included in the net area available to the hens (also referred to as usable area) when calculating maximum indoor stocking densities in organic systems within the EU. In this article, results on live weight, health measures and perching are reported for organic laying hens housed in a multi-tier system with permanent access to a veranda and kept at stocking densities (D) of 6, 9 and 12 hens/m2 available floor area, with concomitant increases in the number of hens per trough, drinker, perch and nest space. In a fourth treatment, access to the top tier was blocked reducing vertical, trough, and perch access at the lowest stocking density (D6x). In all other aspects than stocking density, the experiment followed the EU regulations on the keeping of organic laying hens. Hen live weight, mortality and foot health were not affected by the stocking densities used in the present study. Other variables (plumage condition, presence of breast redness and blisters, pecked tail feathers, and perch use) were indirectly affected by the increase in stocking density through the simultaneous reduction in access to other resources, mainly perches and troughs. The welfare of the hens was mostly affected by these associated constraints, despite all of them being within the allowed minimum requirements for organic production in the EU. Although the welfare consequences reported here were assessed to be moderate to minor, it is important to take into account concurrent constraints on access to other resources when higher stocking densities are used in organic production.

Rootless shield and perched lava pond collapses at Kīlauea Volcano, Hawai'i

USGS Publications Warehouse

Patrick, Matthew R.; Orr, Tim R.

2012-01-01

Effusion rate is a primary measurement used to judge the expected advance rate, length, and hazard potential of lava flows. At basaltic volcanoes, the rapid draining of lava stored in rootless shields and perched ponds can produce lava flows with much higher local effusion rates and advance velocities than would be expected based on the effusion rate at the vent. For several months in 2007–2008, lava stored in a series of perched ponds and rootless shields on Kīlauea Volcano, Hawai'i, was released episodically to produce fast-moving 'a'ā lava flows. Several of these lava flows approached Royal Gardens subdivision and threatened the safety of remaining residents. Using time-lapse image measurements, we show that the initial time-averaged discharge rate for one collapse-triggered lava flow was approximately eight times greater than the effusion rate at the vent. Though short-lived, the collapse-triggered 'a'ā lava flows had average advance rates approximately 45 times greater than that of the pāhoehoe flow field from which they were sourced. The high advance rates of the collapse-triggered lava flows demonstrates that recognition of lava accumulating in ponds and shields, which may be stored in a cryptic manner, is vital for accurately assessing short-term hazards at basaltic volcanoes.

Are sex steroids involved in the sexual growth dimorphism in Eurasian perch juveniles?

PubMed

Mandiki, S N M; Houbart, M; Babiak, I; Vandeloise, E; Gardeur, J N; Kestemont, P

2004-02-01

Individual growth and food intake were monitored in Eurasian perch (Perca fluviatilis L.) juveniles (13.5+/-3.4 g initial body weight) to determine whether androgens and estrogens may mediate sex-related growth differences. Fish were individually tagged with chips and implanted with cocoa butter containing 20 microg of either 17alpha-methyltestosterone (MT) or 17beta-estradiol (E(2)) per gram of fish body; controls were implanted with cocoa butter without hormones. All fish were bled at the end of the experiment for measurement of E(2) in females and testosterone (T) in males (MT was not measured) and triiodothyronine (T3) in both genders. Survival, gonadosomatic index and hepatosomatic index were not affected by steroid treatments. Relative food intake (RFI), feed efficiency (FE) and specific growth rate (SGR) were higher in females than in males in all treatments. MT treatment significantly lowered RIF, FE and SGR in both sexes, while E(2) treatment showed no significant effect on growth and feeding parameters. In contrast to E(2) and T concentrations, T3 levels were significantly and positively correlated with SGR and RFI. The results provide evidence that MT may affect sexually related growth dimorphism by decreasing food intake and FE in Eurasian perch.

Movements of yellow perch marked in southern Green Bay, Lake Michigan, in 1950

USGS Publications Warehouse

Mraz, Donald

1952-01-01

These investigations have demonstrated that for studying migration of yellow perch, tagging is superior to fin-clipping as a method of marking. The technique of the tagging, however, needs to be improved, and better means must be found to trace tagged fish of small size. Furthermore certain small regions in the bay not at present open to commercial fishing must be explored in order to obtain more comprehensive information as to migration.

Evaluating the spatial variation of total mercury in young-of-year yellow perch (Perca flavescens), surface water and upland soil for watershed-lake systems within the southern Boreal Shield

Treesearch

Mark C. Gabriel; Randy Kolka; Trent Wickman; Ed Nater; Laurel. Woodruff

2009-01-01

The primary objective of this research is to investigate relationships between mercury in upland soil, lake water and fish tissue and explore the cause for the observed spatial variation of THg in age one yellow perch (Perca flavescens) for ten lakes within the Superior National Forest. Spatial relationships between yellow perch THg tissue...

Structure-Forming Corals and Sponges and Their Use as Fish Habitat in Bering Sea Submarine Canyons

PubMed Central

Miller, Robert J.; Hocevar, John; Stone, Robert P.; Fedorov, Dmitry V.

2012-01-01

Continental margins are dynamic, heterogeneous settings that can include canyons, seamounts, and banks. Two of the largest canyons in the world, Zhemchug and Pribilof, cut into the edge of the continental shelf in the southeastern Bering Sea. Here currents and upwelling interact to produce a highly productive area, termed the Green Belt, that supports an abundance of fishes and squids as well as birds and marine mammals. We show that in some areas the floor of these canyons harbors high densities of gorgonian and pennatulacean corals and sponges, likely due to enhanced surface productivity, benthic currents and seafloor topography. Rockfishes, including the commercially important Pacific ocean perch, Sebastes alutus, were associated with corals and sponges as well as with isolated boulders. Sculpins, poachers and pleuronectid flounders were also associated with corals in Pribilof Canyon, where corals were most abundant. Fishes likely use corals and sponges as sources of vertical relief, which may harbor prey as well as provide shelter from predators. Boulders may be equivalent habitat in this regard, but are sparse in the canyons, strongly suggesting that biogenic structure is important fish habitat. Evidence of disturbance to the benthos from fishing activities was observed in these remote canyons. Bottom trawling and other benthic fishing gear has been shown to damage corals and sponges that may be very slow to recover from such disturbance. Regulation of these destructive practices is key to conservation of benthic habitats in these canyons and the ecosystem services they provide. PMID:22470486

Structure-forming corals and sponges and their use as fish habitat in Bering Sea submarine canyons.

PubMed

Miller, Robert J; Hocevar, John; Stone, Robert P; Fedorov, Dmitry V

2012-01-01

Continental margins are dynamic, heterogeneous settings that can include canyons, seamounts, and banks. Two of the largest canyons in the world, Zhemchug and Pribilof, cut into the edge of the continental shelf in the southeastern Bering Sea. Here currents and upwelling interact to produce a highly productive area, termed the Green Belt, that supports an abundance of fishes and squids as well as birds and marine mammals. We show that in some areas the floor of these canyons harbors high densities of gorgonian and pennatulacean corals and sponges, likely due to enhanced surface productivity, benthic currents and seafloor topography. Rockfishes, including the commercially important Pacific ocean perch, Sebastes alutus, were associated with corals and sponges as well as with isolated boulders. Sculpins, poachers and pleuronectid flounders were also associated with corals in Pribilof Canyon, where corals were most abundant. Fishes likely use corals and sponges as sources of vertical relief, which may harbor prey as well as provide shelter from predators. Boulders may be equivalent habitat in this regard, but are sparse in the canyons, strongly suggesting that biogenic structure is important fish habitat. Evidence of disturbance to the benthos from fishing activities was observed in these remote canyons. Bottom trawling and other benthic fishing gear has been shown to damage corals and sponges that may be very slow to recover from such disturbance. Regulation of these destructive practices is key to conservation of benthic habitats in these canyons and the ecosystem services they provide.

An update of hydrologic conditions and distribution of selected constituents in water, eastern Snake River Plain aquifer and perched groundwater zones, Idaho National Laboratory, Idaho, emphasis 2012-15

USGS Publications Warehouse

Bartholomay, Roy C.; Maimer, Neil V.; Rattray, Gordon W.; Fisher, Jason C.

2017-04-10

Since 1952, wastewater discharged to in ltration ponds (also called percolation ponds) and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the eastern Snake River Plain (ESRP) aquifer and perched groundwater zones underlying the INL. The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, maintains groundwater-monitoring networks at the INL to determine hydrologic trends and to delineate the movement of radiochemical and chemical wastes in the aquifer and in perched groundwater zones. This report presents an analysis of water-level and water-quality data collected from the ESRP aquifer, multilevel monitoring system (MLMS) wells in the ESRP aquifer, and perched groundwater wells in the USGS groundwater monitoring networks during 2012-15.

Feasibility of partial replacement of fishmeal with proteins from different sources in diets of Korean rockfish ( Sebastes schlegeli)

NASA Astrophysics Data System (ADS)

Yan, Quangen; Zhu, Xiaoming; Yang, Yunxia; Han, Dong; Xie, Shouqi

2014-12-01

An 8-week feeding experiment was conducted in an indoor recirculation seawater system to investigate the effects of partial replacement of dietary fishmeal with proteins from five sources on the growth performance and feed utilization of Sebastes schlegeli. Six isonitrogenous and isoenergetic diets were formulated using fishmeal (FM, the control) as sole protein source, or proteins from five sources including poultry by-product meal (PBM), meat and bone meal (MBM), soybean meal (SBM), cottonseed meal (CSM) and canola meal (CNM). Fifteen percent of the crude protein provided by fish meal was replaced, respectively. The results showed that the differences in specific growth rate (SGR) and survival rate (SR) among fish fed PBM, MBM, SBM, CSM and whole FM diets were not significant. However, SGR and SR of fish fed CNM diet was significantly lower than that of other treatments. Feeding rate, feed conversion, nutrient retention showed similar patterns to that of growth. Fish fed CSM and CNM showed significantly lower apparent digestibility coefficient (ADC) of dry matter and gross energy than those fed others while fish fed CNM showed lower ADC of crude protein than those fed others ( P<0.05). These results suggested that it was feasible to substitute 15% dietary protein provided by fishmeal with PBM, MBM, SBM and CSM, respectively, but not with CNM as the replacement with CNM reduced fish growth and feed utilization.

From yellow perch to round goby: A review of double-crested cormorant diet and fish consumption at three St. Lawrence River colonies, 1999–2013

USGS Publications Warehouse

Johnson, James H.; Farquhar, James F.; Klindt, Rodger M; Mazzocchi, Irene; Mathers, Alastair

2015-01-01

The number of double-crested cormorants (Phalacrocorax auritus) in the upper St. Lawrence River has increased markedly since the early 1990s. In 1999, a binational study was initiated to examine the annual diet composition and fish consumption of cormorants at colonies in the upper river. Since 1999, 14,032 cormorant pellets, collected from May through September each year, have been examined from St. Lawrence River colonies to estimate fish consumption and determine temporal and spatial variation in diet. Seasonal variation in diet composition within a colony was low. Prior to 2006 yellow perch was the primary fish consumed by cormorants in the upper St. Lawrence River. Round goby were first observed in cormorant diets in 2003 and by 2006 were the main fish consumed at two of the three colonies. The time interval it took from the first appearance of round goby in the diet at a colony to when goby were the dominant prey species varied by island, ranging from two to five years. Daily fish consumption at each cormorant colony increased significantly from the pre-round goby to post-round goby period. The mean annual biomass of yellow perch consumed decreased significantly during the post-round goby period at the three colonies. Reduced consumption of yellow perch by cormorants may alleviate suspected localized impacts on perch near some of the larger river colonies.

Genetic Variation of 17 Wild Yellow Perch Populations from the Midwest and East Coast Analyzed Via Microsatellites

USDA-ARS?s Scientific Manuscript database

We used microsatellite loci, including seven newly developed by us, to analyze the population genetic structure of wild yellow perch Perca flavescens from 17 sampling areas in the Upper Midwest and East Coast of the United States. Our results revealed greater genetic differentiation and finer-scale ...

A robin perches on a branch at KSC

NASA Technical Reports Server (NTRS)

1999-01-01

A robin perches on a branch in the Merritt Island National Wildlife Refuge, which shares a boundary with the space center. Robins range throughout North America, from Alaska to Florida. Although considered a harbinger of spring, they do winter in northern states, frequenting cedar bogs and swamps. They also winter in Florida, where they often can be seen in flocks of hundreds near KSC and the wildlife refuge, which comprises 92,000 acres, ranging from hardwood hammocks and pine flatwoods to fresh-water impoundments, salt-water estuaries and brackish marshes. The diverse landscape provides habitat for more than 310 species of birds, 25 mammals, 117 fishes, and 65 amphibians and reptiles, including such endangered species as Southern bald eagles, wood storks, Florida scrub jays, Atlantic loggerhead and leatherback turtles, osprey, and nearly 5,000 alligators.

Extensive length variation in the ribosomal DNA intergenic spacer of yellow perch (Perca flavescens).

PubMed

Kakou, Bidénam; Angers, Bernard; Glémet, Hélène

2016-03-01

The intergenic spacer (IGS) is located between ribosomal RNA (rRNA) gene copies. Within the IGS, regulatory elements for rRNA gene transcription are found, as well as a varying number of other repetitive elements that are at the root of IGS length heterogeneity. This heterogeneity has been shown to have a functional significance through its effect on growth rate. Here, we present the structural organization of yellow perch (Perca flavescens) IGS based on its entire sequence, as well as the IGS length variation within a natural population. Yellow perch IGS structure has four discrete regions containing tandem repeat elements. For three of these regions, no specific length class was detected as allele size was seemingly normally distributed. However, for one repeat region, PCR amplification uncovered the presence of two distinctive IGS variants representing a length difference of 1116 bp. This repeat region was also devoid of any CpG sites despite a high GC content. Balanced selection may be holding the alleles in the population and would account for the high diversity of length variants observed for adjacent regions. Our study is an important precursor for further work aiming to assess the role of IGS length variation in influencing growth rate in fish.

Elevated temperature and acclimation time affect metabolic performance in the heavily exploited Nile perch of Lake Victoria.

PubMed

Nyboer, Elizabeth A; Chapman, Lauren J

2017-10-15

Increasing water temperatures owing to anthropogenic climate change are predicted to negatively impact the aerobic metabolic performance of aquatic ectotherms. Specifically, it has been hypothesized that thermal increases result in reductions in aerobic scope (AS), which lead to decreases in energy available for essential fitness and performance functions. Consequences of warming are anticipated to be especially severe for warm-adapted tropical species as they are thought to have narrow thermal windows and limited plasticity for coping with elevated temperatures. In this study we test how predicted warming may affect the aerobic performance of Nile perch ( Lates niloticus ), a commercially harvested fish species in the Lake Victoria basin of East Africa. We measured critical thermal maxima (CT max ) and key metabolic variables such as AS and excess post-exercise oxygen consumption (EPOC) across a range of temperatures, and compared responses between acute (3-day) exposures and 3-week acclimations. CT max increased with acclimation temperature; however, 3-week-acclimated fish had higher overall CT max than acutely exposed individuals. Nile perch also showed the capacity to increase or maintain high AS even at temperatures well beyond their current range; however, acclimated Nile perch had lower AS compared with acutely exposed fish. These changes were accompanied by lower EPOC, suggesting that drops in AS may reflect improved energy utilization after acclimation, a finding that is supported by improvements in growth at high temperatures over the acclimation period. Overall, the results challenge predictions that tropical species have limited thermal plasticity, and that high temperatures will be detrimental because of limitations in AS. © 2017. Published by The Company of Biologists Ltd.

Timing, frequency and environmental conditions associated with mainstem-tributary movement by a lowland river fish, golden perch (Macquaria ambigua).

PubMed

Koster, Wayne M; Dawson, David R; O'Mahony, Damien J; Moloney, Paul D; Crook, David A

2014-01-01

Tributary and mainstem connections represent important links for the movement of fish and other biota throughout river networks. We investigated the timing, frequency and environmental conditions associated with movements by adult golden perch (Macquaria ambigua) between the mainstem of the mid-Murray River and a tributary, the Goulburn River, in south-eastern Australia, using acoustic telemetry over four years (2007-2011). Fish were tagged and released in autumn 2007-2009 in the mid-Murray (n = 42) and lower Goulburn (n = 37) rivers within 3-6 km of the mid-Murray-lower Goulburn junction. 38% of tagged fish undertook mainstem-tributary movements, characterised mostly by temporary occupation followed by return of fish to the original capture river. Approximately 10% of tagged fish exhibited longer-term shifts between the mainstem and tributary. Movement of fish from the tributary into the mainstem occurred primarily during the spawning season and in some years coincided with the presence of golden perch eggs/larvae in drift samples in the mainstem. Many of the tributary-to-mainstem movements occurred during or soon after changes in flow. The movements of fish from the mainstem into the tributary were irregular and did not appear to be associated with spawning. The findings show that golden perch moved freely across the mainstem-tributary interface. This demonstrates the need to consider the spatial, behavioural and demographic interdependencies of aquatic fauna across geographic management units such as rivers.

Timing, Frequency and Environmental Conditions Associated with Mainstem–Tributary Movement by a Lowland River Fish, Golden Perch (Macquaria ambigua)

PubMed Central

Koster, Wayne M.; Dawson, David R.; O’Mahony, Damien J.; Moloney, Paul D.; Crook, David A.

2014-01-01

Tributary and mainstem connections represent important links for the movement of fish and other biota throughout river networks. We investigated the timing, frequency and environmental conditions associated with movements by adult golden perch (Macquaria ambigua) between the mainstem of the mid-Murray River and a tributary, the Goulburn River, in south-eastern Australia, using acoustic telemetry over four years (2007–2011). Fish were tagged and released in autumn 2007–2009 in the mid-Murray (n = 42) and lower Goulburn (n = 37) rivers within 3–6 km of the mid-Murray-lower Goulburn junction. 38% of tagged fish undertook mainstem–tributary movements, characterised mostly by temporary occupation followed by return of fish to the original capture river. Approximately 10% of tagged fish exhibited longer-term shifts between the mainstem and tributary. Movement of fish from the tributary into the mainstem occurred primarily during the spawning season and in some years coincided with the presence of golden perch eggs/larvae in drift samples in the mainstem. Many of the tributary-to-mainstem movements occurred during or soon after changes in flow. The movements of fish from the mainstem into the tributary were irregular and did not appear to be associated with spawning. The findings show that golden perch moved freely across the mainstem–tributary interface. This demonstrates the need to consider the spatial, behavioural and demographic interdependencies of aquatic fauna across geographic management units such as rivers. PMID:24788137

Depletion of the chloramine-T marker residue, para-toluenesulfonamide, from skin-on fillet tissue of hybrid striped bass, rainbow trout, and yellow perch

USGS Publications Warehouse

Meinertz, J.R.; Stehly, G.R.; Greseth, Shari L.; Gaikowski, M.P.; Gingerich, W.H.

2004-01-01

Waterborne exposure to n-sodium-n-chloro-p-toluenesulfonamide (chloramine-T) is an effective treatment for controlling fish mortalities caused by bacterial gill disease (BGD). Currently, data are being generated to gain United States Food and Drug Administration (FDA) approval for the use of chloramine-T in aquaculture. As part of the data required for an approval, depletion of the chloramine-T marker residue (para-toluenesulfonamide [p-TSA]) from the edible fillet tissue of exposed fish must be determined. Hybrid striped bass (Morone saxatilis??Morone chrysops; mean weight 357 g), rainbow trout (Oncorhynchus mykiss; mean weight 457 g), and yellow perch (Perca flavescens; mean weight 144 g) were exposed to 20 mg/l of chloramine-T for 60 min on 4 consecutive days (the most aggressive treatment expected for approved use in the United States). Groups of fish (n=15 or 19) were sampled immediately after the last treatment and periodically through 48 or 168 h after the treatment phase. Duplicate subsamples of skin-on fillet tissue from each fish were analyzed for p-TSA. Mean p-TSA concentrations in fillet tissue from fish sampled immediately after the last treatment were 142 ng/g (hybrid striped bass), 97 ng/g (rainbow trout), and 150 ng/g (yellow perch). Mean p-TSA concentrations at terminal sample times were 94 (168 h; hybrid striped bass), 74 (48 h; rainbow trout), and 35 ng/g (168 h; yellow perch). The half-lives of p-TSA in fillet tissue from fish near or at market size were 11.4 (hybrid striped bass), 4.3 (rainbow trout), and 3.2 days (yellow perch).

Composition and Use of Common Carp Meal as a Marine Fish Meal Replacement in Yellow Perch Diets

USDA-ARS?s Scientific Manuscript database

We evaluated the use of fish meal derived from a locally abundant, non-native fish species – common carp Cyprinus carpio – with the objective of offsetting the cost of marine fish meal (MFM, ~$1,200/ton) in yellow perch Perca flavescens feed. Biochemical analyses of meals showed that crude protein a...

An integrative mating system assessment of a nonmodel, economically important Pacific rockfish (Sebastes melanops) reveals nonterritorial polygamy and conservation implications for a large species flock.

PubMed

Karageorge, Kurt W; Wilson, Raymond R

2017-12-01

Characterizing the mating systems of long-lived, economically important Pacific rockfishes comprising the viviparous Sebastes species flock is crucial for their conservation. However, direct assignment of mating success to sires is precluded by open, offshore populations and high female fecundity. We addressed this challenge by integrating paternity-assigned mating success of females with the adult sex ratio (ASR) of the population, male evolutionary responses to receptive females, and reproductive life history traits-in the framework of sexual selection theory-to assess the mating system of Sebastes melanops . Microsatellite parentage analysis of 17 pregnant females, 1,256 of their progeny, and 106 adults from the population yielded one to four sires per brood, a mean of two sires, and a female mate frequency distribution with a truncated normal (random) pattern. The 11 multiple paternity broods all contained higher median allele richness than the six single paternity broods (Wilcoxon test: W  = 0, p  < .001), despite similar levels of average heterozygosity. By sampling sperm and alleles from different males, polyandrous females gain opportunities to enhance their sperm supply and to lower the cost of mating with genetically incompatible males through reproductive compensation. A mean of two mates per mated female with a variance of one, an ASR = 1.2 females per male, and the expected population mean of 2.4 mates for mated males (and the estimated 35 unavailable sires), fits polygamous male mate frequency distributions that distinguish polygynandry and polyandrogyny mating systems, that is, variations of polygamy, but not polyandry. Inference for polygamy is consistent with weak premating sexual selection on males, expected in mid-water, schooling S. melanops , owing to polyandrous mating, moderately aggregated receptive females, an even ASR, and no territories and nests used for reproduction. Each of these characteristics facilitates more mating males and

Evaluation of rockfish conservation area networks in the United States and Canada relative to the dispersal distance for black rockfish (Sebastes melanops)

PubMed Central

Lotterhos, Katie E; Dick, Stefan J; Haggarty, Dana R

2014-01-01

Marine reserves networks are implemented as a way to mitigate the impact of fishing on marine ecosystems. Theory suggests that a reserve network will function synergistically when connected by dispersal, but the scale of dispersal is often unknown. On the Pacific coast of the United States and Canada, both countries have recently implemented a number of rockfish conservation areas (RCAs) to protect exploited rockfish species, but no study has evaluated the connectivity within networks in each country or between the two countries. We used isolation-by-distance theory to estimate the scale of dispersal from microsatellite data in the black rockfish, Sebastes melanops, and compared this estimate with the distance between RCAs that would protect this species. Within each country, we found that the distance between RCAs was generally within the confidence intervals of mean dispersal per generation. The distance between these two RCA networks, however, was greater than the average dispersal per generation. The data were also consistent with a genetic break between southern Oregon and central Oregon. We discuss whether additional nearshore RCAs in southern Oregon and Washington would help promote connectivity between RCA's for shallow-water rockfishes. PMID:24567745

Identification of gender in yellow perch by external morphology: validation in four geographic strains and effects of estradiol

USDA-ARS?s Scientific Manuscript database

External morphological criteria that enable the rapid determination of gender have been developed for yellow perch (Perca flavescens). Criteria are based upon 1) shape of the urogenital papilla (UGP), 2) relative size of the UGP to the anal (AN) opening, and 3) coloration of the UGP. In females, t...

Developing a 3-DOF Compliant Perching Arm for a Free-Flying Robot on the International Space Station

NASA Technical Reports Server (NTRS)

Park, In-Won; Smith, Marion F.; Sanchez, Hugo S.; Wong, Sze Wun; Piacenza, Pedro; Ciocarlie, Matei

2017-01-01

This paper presents the design and control of the 3-DOF compliant perching arm for the free-flying Astrobee robots that will operate inside the International Space Station (ISS). The robots are intended to serve as a flexible platform for future guest scientists to use for zero-gravity robotics research - thus, the arm is designed to support manipulation research. It provides a 1-DOF underactuated tendon-driven gripper capable of enveloping a range of objects of different shapes and sizes. Co-located RGB camera and LIDAR sensors provide perception. The Astrobee robots will be capable of grasping each other in flight, to simulate orbital capture scenarios. The arm's end-effector module is swappable on-orbit, allowing guest scientists to add upgraded grippers, or even additional arm degrees of freedom. The design of the arm balances research capabilities with Astrobee's operational need to perch on ISS handrails to reduce power consumption. Basic arm functioning and grip strength were evaluated using an integrated Astrobee prototype riding on a low-friction air bearing.

Methylmercury content of eggs in yellow perch related to maternal exposure in four Wisconsin lakes

USGS Publications Warehouse

Hammerschmidt, Chad R.; Wiener, James G.; Frazier, Brdaley E.; Rada, Ronald G.

1999-01-01

We examined the influence of maternal mercury and selected lacustrine variables on the mercury content of eggs from yellow perch (Perca flavescens). Total mercury, methylmercury, and inorganic mercury were determined in eggs and carcasses (less eggs) from three seepage lakes with a pH range of 6.1a??7.0 and a fourth lake in which pH was experimentally increased from 5.5 to 6.8 by addition of alkaline groundwater. The concentration of total mercury in eggs was strongly correlated with that in the maternal carcass. Concentrations and burdens of mercury in eggs and carcasses were inversely correlated with lake water pH, acid-neutralizing capacity, calcium, and dissolved organic carbon. In eggs containing more than 30 ng/g dry weight (4.5 ng/g wet weight) of total mercury, methylmercury averaged 91% of total mercury and ranged from 85% to 96%. Mean burdens of total mercury in individual eggs varied greatly among lakes (range, 2.3a??63 pg), and the egg mass averaged 1.9% of the whole-body burden. We conclude that exposure of the developing yellow perch embryo to methylmercury is strongly affected by maternal bioaccumulation, which can vary substantially among and within lakes; however, the toxicological significance of the observed exposure of embryos to methylmercury is unclear.

Methylmercury content of eggs in yellow perch related to maternal exposure in four Wisconsin lakes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hammerschmidt, C.R.; Frazier, B.E.; Rada, R.G.

1999-04-01

The authors examined the influence of maternal mercury and selected lacustrine variables on the mercury content of eggs from yellow perch (Perca flavescens). Total mercury, methylmercury, and inorganic mercury were determined in eggs and carcasses (less eggs) from three seepage lakes with a pH range of 6.1--7.0 and a fourth lake in which pH was experimentally increased from 5.5 to 6.8 by addition of alkaline groundwater. The concentration of total mercury in eggs was strongly correlated with that in the material carcass. Concentrations and burdens of mercury in eggs and carcasses were inversely correlated with lake water pH, acid-neutralizing capacity,more » calcium, and dissolved organic carbon. In eggs containing more than 30 ng/g dry weight of total mercury, methylmercury averaged 91% of total mercury and ranged from 85% to 96%. Mean burdens of total mercury in individual eggs varied greatly among lakes and the egg mass averaged 1.9% of the whole-body burden. The authors conclude that exposure of the developing yellow perch embryo to methylmercury is strongly affected by maternal bioaccumulation, which can vary substantially among and within lakes; however, the toxicological significance of the observed exposure of embryos to methylmercury is unclear.« less

Comparative population genetic structure and diversity of Yellow Perch and Walleye: Broad- and fine-scale patterns across North America

USDA-ARS?s Scientific Manuscript database

The yellow perch Perca flavescens and the walleye Sander vitreus are native North American percid fishes, which have considerable fishery and ecological importance across their wide geographic ranges. Over the past century, they were stocked into new habitats, often with relative disregard for conse...

Temperature preference of the white perch, Morone americana, collected in the Wicomico River, Maryland

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hall, L.W. Jr.; Hocutt, C.H.; Stauffer, J.R. Jr.

1979-06-01

Temperature preference tests were conducted on fresh water white perch (Morone americana), collected from the Wicomico River, Maryland. Collection temperature was 27/sup 0/C and acclimation temperatures used in temperature preference tests were 6, 12, 18, 24, 30, and 33/sup 0/C. The following methods were used to determine the final temperature preference:linear regression, quadratic equation, and eyeball plots. Recorded final temperature preference values were 28.9, 29.3, and 30.6/sup 0/C using each method respectively.

Prevalence and spatial distribution of intraerythrocytic parasite(s) in Puget Sound rockfish (Sebastes emphaeus) from the San Juan Archipelago, Washington (USA)

USGS Publications Warehouse

Van Der Straaten, N.; Jacobson, A.; Halos, D.; Hershberger, P.; Kocan, A.A.; Kocan, R.

2005-01-01

Two morphologically distinct forms of an intraerythrocytic parasite(s) were detected by microscopic observation of Giemsa-stained blood films in 45.7% of 119 rockfish (Sebastes emphaeus) from the San Juan Archipelago (Washington State, U.S.A.). Infection prevalence for both forms was 53% in males, 44% in females, and 33% in fish of undetermined gender. A binucleate "ring-stage" was present at all 4 geographic sites, with a mean prevalence of 45.7%, while mean prevalence of a larger gamont-like form from the same sites was 5.1%. The relationship of the 2 forms to each other could not be determined. Neither schizogony nor binary fission was evident in any of the infected erythrocytes and the parasites contained no obvious pigment. The possibility of the 2 morphologic forms being 2 distinct species is supported by the observation that no difference in parasitemia was seen in the binucleate form among sites (1.6-1.9%), while parasitemia of the gamont-like form varied significantly among sites, ranging from a high of 4% to a low of 0.1%. Taxonomic status of either form could not be determined at this time based on limited existing morphologic data. ?? American Society of Parasitologists 2005.

The immune responses and expression of metallothionein (MT) gene and heat shock protein 70 (HSP 70) in juvenile rockfish, Sebastes schlegelii, exposed to waterborne arsenic (As3+).

PubMed

Kim, Jun-Hwan; Kang, Ju-Chan

2016-10-01

Juvenile rockfish, Sebastes schlegelii (mean length 16.4±1.9cm, and mean weight 71.6±6.4g) were exposed for 20days with the different levels of waterborne arsenic concentration (0, 50, 100, 200 and 400μg/L). The plasma cortisol of S. schlegelii was significantly increased by the waterborne arsenit exposure. In the immune responses, the immunoglobulin M (Ig M) and lysozyme activity of S. schlegelii were significantly increased by the waterborne arsenic exposure. The acetylcholinesterase (AChE) activity of S. schlegelii was inhibited by the waterborne arsenic exposure. The substantial increases in the gene expression such as metallothionein (MT) and heat shock protein 70 (HSP 70) were observed by the waterborne arsenic exposure. The results demonstrated that waterborne arsenic exposure can induce the significant alterations in the immune responses and specific gene expression of S. schlegelii. Copyright © 2016 Elsevier B.V. All rights reserved.

Development of yellow perch (Perca flavescens) broodstocks: initial characterization of growth and quality traits following grow-out of different stocks

USDA-ARS?s Scientific Manuscript database

Broodstocks of yellow perch (Perca flavescens) were initiated from fertilized gametes obtained from wild fish taken from the Perquimans River (North Carolina), Choptank River (Maryland), Lake Winnebago (Wisconsin), and Lac du Flambeau (Wisconsin). Populations at these sites were chosen based on the ...

An update of hydrologic conditions and distribution of selected constituents in water, Snake River Plain aquifer and perched groundwater zones, Idaho National Laboratory, Idaho, emphasis 2006-08

USGS Publications Warehouse

Davis, Linda C.

2010-01-01

Since 1952, radiochemical and chemical wastewater discharged to infiltration ponds (also called percolation ponds), evaporation ponds, and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the eastern Snake River Plain aquifer and perched groundwater zones underlying the INL. The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, maintains groundwater monitoring networks at the INL to determine hydrologic trends, and to delineate the movement of radiochemical and chemical wastes in the aquifer and in perched groundwater zones. This report presents an analysis of water-level and water-quality data collected from aquifer and perched groundwater wells in the USGS groundwater monitoring networks during 2006-08. Water in the Snake River Plain aquifer primarily moves through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer primarily is recharged from infiltration of irrigation water, infiltration of streamflow, groundwater inflow from adjoining mountain drainage basins, and infiltration of precipitation. From March-May 2005 to March-May 2008, water levels in wells generally remained constant or rose slightly in the southwestern corner of the INL. Water levels declined in the central and northern parts of the INL. The declines ranged from about 1 to 3 feet in the central part of the INL, to as much as 9 feet in the northern part of the INL. Water levels in perched groundwater wells around the Advanced Test Reactor Complex (ATRC) also declined. Detectable concentrations of radiochemical constituents in water samples from wells in the Snake River Plain aquifer at the INL generally decreased or remained constant during 2006-08. Decreases in concentrations were attributed to decreased rates of radioactive-waste disposal, radioactive decay, changes in waste-disposal methods, and dilution from recharge and underflow. In April

An Update of Hydrologic Conditions and Distribution of Selected Constituents in Water, Snake River Plain Aquifer and Perched-Water Zones, Idaho National Laboratory, Idaho, Emphasis 2002-05

USGS Publications Warehouse

Davis, Linda C.

2008-01-01

Radiochemical and chemical wastewater discharged since 1952 to infiltration ponds, evaporation ponds, and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the Snake River Plain aquifer and perched-water zones underlying the INL. The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, maintains ground-water monitoring networks at the INL to determine hydrologic trends, and to delineate the movement of radiochemical and chemical wastes in the aquifer and in perched-water zones. This report presents an analysis of water-level and water-quality data collected from aquifer and perched-water wells in the USGS ground-water monitoring networks during 2002-05. Water in the Snake River Plain aquifer primarily moves through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer is recharged primarily from infiltration of irrigation water, infiltration of streamflow, ground-water inflow from adjoining mountain drainage basins, and infiltration of precipitation. From March-May 2001 to March-May 2005, water levels in wells declined throughout the INL area. The declines ranged from about 3 to 8 feet in the southwestern part of the INL, about 10 to 15 feet in the west central part of the INL, and about 6 to 11 feet in the northern part of the INL. Water levels in perched water wells declined also, with the water level dropping below the bottom of the pump in many wells during 2002-05. For radionuclides, concentrations that equal 3s, wheres s is the sample standard deviation, represent a measurement at the minimum detectable concentration, or 'reporting level'. Detectable concentrations of radiochemical constituents in water samples from wells in the Snake River Plain aquifer at the INL generally decreased or remained constant during 2002-05. Decreases in concentrations were attributed to decreased rates of radioactive-waste disposal

Evaluating the spatial variation of total mercury in young-of-year yellow perch (Perca flavescens), surface water and upland soil for watershed-lake systems within the southern Boreal Shield.

PubMed

Gabriel, Mark C; Kolka, Randy; Wickman, Trent; Nater, Ed; Woodruff, Laurel

2009-06-15

The primary objective of this research is to investigate relationships between mercury in upland soil, lake water and fish tissue and explore the cause for the observed spatial variation of THg in age one yellow perch (Perca flavescens) for ten lakes within the Superior National Forest. Spatial relationships between yellow perch THg tissue concentration and a total of 45 watershed and water chemistry parameters were evaluated for two separate years: 2005 and 2006. Results show agreement with other studies where watershed area, lake water pH, nutrient levels (specifically dissolved NO(3)(-)-N) and dissolved iron are important factors controlling and/or predicting fish THg level. Exceeding all was the strong dependence of yellow perch THg level on soil A-horizon THg and, in particular, soil O-horizon THg concentrations (Spearman rho=0.81). Soil B-horizon THg concentration was significantly correlated (Pearson r=0.75) with lake water THg concentration. Lakes surrounded by a greater percentage of shrub wetlands (peatlands) had higher fish tissue THg levels, thus it is highly possible that these wetlands are main locations for mercury methylation. Stepwise regression was used to develop empirical models for the purpose of predicting the spatial variation in yellow perch THg over the studied region. The 2005 regression model demonstrates it is possible to obtain good prediction (up to 60% variance description) of resident yellow perch THg level using upland soil O-horizon THg as the only independent variable. The 2006 model shows even greater prediction (r(2)=0.73, with an overall 10 ng/g [tissue, wet weight] margin of error), using lake water dissolved iron and watershed area as the only model independent variables. The developed regression models in this study can help with interpreting THg concentrations in low trophic level fish species for untested lakes of the greater Superior National Forest and surrounding Boreal ecosystem.

Effect of pH on Structural Changes in Perch Hemoglobin that Can Alter Redox Stability and Heme Affinity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richards, Mark P.; Aranda, IV, Roman; He, Cai

2010-01-07

pH can be manipulated to alter the oxidative stability of fish-based foods during storage. X-ray diffraction was used to investigate the ability of reduced pH to cause structural changes in fish hemoglobins that lead to enhanced oxidative degradation. Decreasing pH from 8.0 to 6.3 and 5.7 created a large channel for solvent entry into the heme crevice of perch hemoglobin beta chains. The proton-induced opening of this channel occurred between site CD3 and the heme-6-propionate. Solvent entry into the heme crevice can enhance metHb formation and hemin loss, processes that accelerate lipid oxidation. Reduced pH also decreased the distance betweenmore » Ile at E11 in one of the alpha chains and the ligand above the heme iron atom. This sterically displaces O{sub 2} and protonated O{sub 2} which increases metHb formation. These studies demonstrate that pH reduction causes structural changes in perch hemoglobin which increase oxidative degradation of the heme pigment.« less

Thermodynamic Equations of State for Aqueous Solutions Applied to Deep Icy Satellite and Exoplanet Oceans

NASA Astrophysics Data System (ADS)

Vance, S.; Brown, J. M.; Bollengier, O.; Journaux, B.; Sotin, C.; Choukroun, M.; Barnes, R.

2014-12-01

Supporting life in icy world or exoplanet oceans may require global seafloor chemical reactions between water and rock. Such interactions have been regarded as limited in larger icy worlds such as Ganymede and Titan, where ocean depths approach 800 km and GPa pressures (>10katm). If the oceans are composed of pure water, such conditions are consistent with the presence of dense ice phases V and VI that cover the rocky seafloor. Exoplanets with oceans can obtain pressures sufficient to generate ices VII and VIII. We have previously demonstrated temperature gradients in such oceans on the order of 20 K or more, resulting from fluid compressibility in a deep adiabatic ocean based on our experimental work. Accounting for increases in density for highly saline oceans leads to the possibility of oceans perched under and between high pressure ices. Ammonia has the opposite effect, instead decreasing ocean density, as reported by others and confirmed by our laboratory measurements in the ammonia water system. Here we report on the completed equation of state for aqueous ammonia derived from our prior measurements and optimized global b-spline fitting methods We use recent diamond anvil cell measurements for water and ammonia to extend the equation of state to 400°C and beyond 2 GPa, temperatures and pressures applicable to icy worlds and exoplanets. Densities show much less temperature dependence but comparabe high-pressure derivatives to previously published ammonia-water properties derived for application to Titan (Croft et al. 1988). Thermal expansion is in better agreement with the more self-consistent equation of state of Tillner-Roth and Friend (1998). We also describe development of a planetary NaCl equation of state using recent measurements of phase boundaries and sound speeds. We examine implications of realistic ocean-ice thermodynamics for Titan and exoplanet interiors using the methodology recently applied to Ganymede for oceans dominated by MgSO4. High

A new classification of a preovulatory oocyte maturation stage suitable for the synchronization of ovulation in controlled reproduction of Eurasian perch Perca fluviatilis L.

PubMed

Zarski, Daniel; Bokor, Zoltán; Kotrik, László; Urbanyi, Béla; Horváth, Akos; Targońska, Katarzyna; Krejszeff, Sławomir; Palińska, Katarzyna; Kucharczyk, Dariusz

2011-11-01

To improve controlled reproduction of Eurasian perch Perca fluviatilis, the criteria for the evaluation of final oocyte maturation stages were revised. The new classification covers six preovulatory maturational stages (I -VI) from the end of vitellogenesis to germinal vesicle breakdown (GVBD) and was based on macroscopic changes of preovulatory oocytes (position of the germinal vesicle, GVBD, oil droplets coalescence). The observation was performed during out-of-season artificial reproduction with the use of a single hCG injection (500 IU/kg). The classification was subsequently verified with the controlled reproduction of wild female perch with the use of hormonal stimulation (500 IU hCG/kg of body weight at 12°C). The females were at different maturational stages and constituted respective experimental groups (I-VI). During the experiment, ovulation appeared to be considerably synchronized within particular groups. Statistical differences in latency time (time between hormonal treatment and ovulation) were found between experimental groups (mean latency time: 110, 92, 68, 49, 29 and 18 h in groups representing VI, V, IV, III, II and I stage of the proposed classification, respectively). The proposed classification and the results presented in the study allowed for effective synchronisation of ovulation. The use of our new oocyte maturation classification may positively influence the effectiveness of Eurasian perch production.

Response of oxidative stress transcripts in the brain of wild yellow perch (Perca flavescens) exposed to an environmental gradient of methylmercury.

PubMed

Graves, Stephanie D; Kidd, Karen A; Batchelar, Katharina L; Cowie, Andrew M; O'Driscoll, Nelson J; Martyniuk, Christopher J

2017-02-01

Methylmercury (MeHg) exposure and adverse health effects in fishes have been documented, but the molecular mechanisms involved in toxicity have not been fully characterized. The objectives of the current study were to (1) determine whether total Hg (THg) in the muscle was predictive of MeHg concentrations in the brain of wild female yellow perch (Perca flavescens) collected from four lakes in Kejimkujik National Park, a known biological mercury (Hg) hotspot in Nova Scotia, Canada and (2) to determine whether transcripts involved in the oxidative stress response were altered in abundance in fish collected across five lakes representing a MeHg gradient. In female yellow perch, MeHg in whole brain (0.38 to 2.00μg/g wet weight) was positively associated with THg in muscle (0.18 to 2.13μg/g wet weight) (R 2 =0.61, p<0.01), suggesting that muscle THg may be useful for predicting MeHg concentrations in the brain. Catalase (cat) mRNA levels were significantly lower in brains of perch collected from lakes with high Hg when compared to those individuals from lakes with relatively lower Hg (p=0.02). Other transcripts (cytochrome c oxidase, glutathione peroxidase, glutathione-s-transferase, heat shock protein 70, protein disulfide isomerase, and superoxide dismutase) did not show differential expression in the brain over the gradient. These findings suggest that MeHg may be inversely associated with catalase mRNA abundance in the central nervous system of wild fishes. Copyright © 2016 Elsevier Inc. All rights reserved.

Microbiological properties and biogenic amines of whole pike-perch (Sander lucioperca, linnaeus 1758): a perspective on fish safety during postharvest handling practices and frozen storage.

PubMed

Ehsani, Ali; Jasour, Mohammad Sedigh

2012-12-01

The biogenic amines (tyramine, histamine, cadaverine, and puterscine) and microbiological properties (mesophilic, psychrotrophic, and Pseudomonas spp.) of whole pike-perch (Sander lucioperca) was investigated during 2 d prestorage icing and 90 d frozen storage (-24 °C). At the end of ice storage, a noticeable increase only was found for puterscine level (P < 0.05), and microbial loads of fish increased in comparison with fresh fish (P < 0.05). During the frozen storage, as time passed, a continuous increase of biogenic amines and decrease of bacterial load (except for Pseudomonas spp. at the last 30 d) was detected (P < 0.05). The total contents of biogenic amines ranged from 6.24 to 91.76 μg/g during the investigated period. Puterscine was the major amine detected in pike-perch and its concentration varied between 1.75 and 56.95 μg/g; due to a more step-wise increase it was a good quality indicator. At the end of storage, all of the obtained values are below the tolerable maximum amounts based on available regulations. Based on biogenic amines content and microbial load, it could be concluded that pike-perch can be consumed without any health risks after 2 d icing condition and 90 d frozen storage. © 2012 Institute of Food Technologists®

Evaluating the spatial variation of total mercury in young-of-year yellow perch (Perca flavescens), surface water and upland soil for watershed-lake systems within the southern Boreal Shield

USGS Publications Warehouse

Gabriel, M.C.; Kolka, R.; Wickman, T.; Nater, E.; Woodruff, Laurel G.

2009-01-01

The primary objective of this research is to investigate relationships between mercury in upland soil, lake water and fish tissue and explore the cause for the observed spatial variation of THg in age one yellow perch (Perca flavescens) for ten lakes within the Superior National Forest. Spatial relationships between yellow perch THg tissue concentration and a total of 45 watershed and water chemistry parameters were evaluated for two separate years: 2005 and 2006. Results show agreement with other studies where watershed area, lake water pH, nutrient levels (specifically dissolved NO3−-N) and dissolved iron are important factors controlling and/or predicting fish THg level. Exceeding all was the strong dependence of yellow perch THg level on soil A-horizon THg and, in particular, soil O-horizon THg concentrations (Spearman ρ = 0.81). Soil B-horizon THg concentration was significantly correlated (Pearson r = 0.75) with lake water THg concentration. Lakes surrounded by a greater percentage of shrub wetlands (peatlands) had higher fish tissue THg levels, thus it is highly possible that these wetlands are main locations for mercury methylation. Stepwise regression was used to develop empirical models for the purpose of predicting the spatial variation in yellow perch THg over the studied region. The 2005 regression model demonstrates it is possible to obtain good prediction (up to 60% variance description) of resident yellow perch THg level using upland soil O-horizon THg as the only independent variable. The 2006 model shows even greater prediction (r2 = 0.73, with an overall 10 ng/g [tissue, wet weight] margin of error), using lake water dissolved iron and watershed area as the only model independent variables. The developed regression models in this study can help with interpreting THg concentrations in low trophic level fish species for untested lakes of the greater Superior National Forest and surrounding Boreal ecosystem.

Intestinal parasite Acanthocephalus lucii (Acanthocephala) from European perch (Perca fluviatilis) as a bioindicator for lead pollution in the stream "Jevanský potok" near Prague, Czech Republic.

PubMed

Jankovská, Ivana; Miholová, Daniela; Petrtýl, Miloslav; Romočuský, Stěpán; Kalous, Lukáš; Vadlejch, Jaroslav; Cadková, Zuzana; Langrová, Iva

2011-03-01

Lead concentrations in the tissues of perch and its parasites were determined as mg/kg dw. Lead was found at higher concentrations in the acanthocephalans (11.56) than in different tissues (liver, gonads and muscle with skin and bone) of perch. With respect to fish tissues, the highest concentrations of lead were present in the liver (1.24), followed by the gonads (0.57) whereas the lowest concentrations were in the muscle with skin and bone (0.21). The bioconcentration factors for lead indicated that parasites accumulate metals to a higher degree than fish tissues--lead concentrations in acanthocephalans were 9.32, 19.27 and 55.05 higher than in liver, gonads and muscles of host, respectively.

Comparative susceptibility among three stocks of yellow perch, Perca flavescens (Mitchill), to viral haemorrhagic septicaemia virus strain IVb from the Great Lakes

USGS Publications Warehouse

Olson, W.; Emmenegger, E.; Glenn, J.; Winton, J.; Goetz, F.

2013-01-01

The Great Lakes strain of viral haemorrhagic septicaemia virus IVb (VHSV-IVb) is capable of infecting a wide number of naive species and has been associated with large fish kills in the Midwestern United States since its discovery in 2005. The yellow perch, Perca flavescens (Mitchill), a freshwater species commonly found throughout inland waters of the United States and prized for its high value in sport and commercial fisheries, is a species documented in several fish kills affiliated with VHS. In the present study, differences in survival after infection with VHSV IVb were observed among juvenile fish from three yellow perch broodstocks that were originally derived from distinct wild populations, suggesting innate differences in susceptibility due to genetic variance. While all three stocks were susceptible upon waterborne exposure to VHS virus infection, fish derived from the Midwest (Lake Winnebago, WI) showed significantly lower cumulative % survival compared with two perch stocks derived from the East Coast (Perquimans River, NC and Choptank River, MD) of the United States. However, despite differences in apparent susceptibility, clinical signs did not vary between stocks and included moderate-to-severe haemorrhages at the pelvic and pectoral fin bases and exophthalmia. After the 28-day challenge was complete, VHS virus was analysed in subsets of whole fish that had either survived or succumbed to the infection using both plaque assay and quantitative PCR methodologies. A direct correlation was identified between the two methods, suggesting the potential for both methods to be used to detect virus in a research setting.

Temperature effects on aerobic scope and cardiac performance of European perch (Perca fluviatilis).

PubMed

Jensen, Denise Lyager; Overgaard, Johannes; Wang, Tobias; Gesser, Hans; Malte, Hans

2017-08-01

Several recent studies have highlighted how impaired cardiac performance at high temperatures and in hypoxia may compromise the capacity for oxygen transport. Thus, at high temperatures impaired cardiac capacity is proposed to reduce oxygen transport to a degree that lowers aerobic scope and compromises thermal tolerance (the oxygen- and capacity-limited thermal tolerance (OCLTT) hypothesis). To investigate this hypothesis, we measured aerobic and cardiac performance of a eurythermal freshwater teleost, the European perch (Perca fluviatilis). Rates of oxygen consumption were measured during rest and activity at temperatures between 5°C and 27°C, and we evaluated cardiac function by in vivo measurements of heart rate and in vitro studies to determine contractility of myocardial strips. Aerobic scope increased progressively from 5°C to 21°C, after which it levelled off. Heart rate showed a similar response. We found little difference between resting and active heart rate at high temperature suggesting that increased cardiac scope during activity is primarily related to changes in stroke volume. To examine the effects of temperature on cardiac capacity, we measured isometric force development in electrically paced myocardial preparations during different combinations of temperature, pacing frequency, oxygenation and adrenergic stimulation. The force-frequency product increased markedly upon adrenergic stimulation at 21 and 27°C (with higher effects at 21°C) and the cardiac preparations were highly sensitive to hypoxia. These findings suggest that at (critically) high temperatures, cardiac output may diminish due to a decreased effect of adrenergic stimulation and that this effect may be further exacerbated if the heart becomes hypoxic. Hence cardiac limitations may contribute to the inability to increase aerobic scope at high temperatures in the European perch (Perca fluviatilis). Copyright © 2017 Elsevier Ltd. All rights reserved.

Hawk eyes II: diurnal raptors differ in head movement strategies when scanning from perches.

PubMed

O'Rourke, Colleen T; Pitlik, Todd; Hoover, Melissa; Fernández-Juricic, Esteban

2010-09-22

Relatively little is known about the degree of inter-specific variability in visual scanning strategies in species with laterally placed eyes (e.g., birds). This is relevant because many species detect prey while perching; therefore, head movement behavior may be an indicator of prey detection rate, a central parameter in foraging models. We studied head movement strategies in three diurnal raptors belonging to the Accipitridae and Falconidae families. We used behavioral recording of individuals under field and captive conditions to calculate the rate of two types of head movements and the interval between consecutive head movements. Cooper's Hawks had the highest rate of regular head movements, which can facilitate tracking prey items in the visually cluttered environment they inhabit (e.g., forested habitats). On the other hand, Red-tailed Hawks showed long intervals between consecutive head movements, which is consistent with prey searching in less visually obstructed environments (e.g., open habitats) and with detecting prey movement from a distance with their central foveae. Finally, American Kestrels have the highest rates of translational head movements (vertical or frontal displacements of the head keeping the bill in the same direction), which have been associated with depth perception through motion parallax. Higher translational head movement rates may be a strategy to compensate for the reduced degree of eye movement of this species. Cooper's Hawks, Red-tailed Hawks, and American Kestrels use both regular and translational head movements, but to different extents. We conclude that these diurnal raptors have species-specific strategies to gather visual information while perching. These strategies may optimize prey search and detection with different visual systems in habitat types with different degrees of visual obstruction.

Parasites as Biological Tags for Stock Discrimination of Beaked Redfish (Sebastes mentella): Parasite Infra-Communities vs. Limited Resolution of Cytochrome Markers

PubMed Central

Klapper, Regina; Kochmann, Judith; O’Hara, Robert B.; Karl, Horst; Kuhn, Thomas

2016-01-01

The use of parasites as biological tags for discrimination of fish stocks has become a commonly used approach in fisheries management. Metazoan parasite community analysis and anisakid nematode population genetics based on a mitochondrial cytochrome marker were applied in order to assess the usefulness of the two parasitological methods for stock discrimination of beaked redfish Sebastes mentella of three fishing grounds in the North East Atlantic. Multivariate, model-based approaches demonstrated that the metazoan parasite fauna of beaked redfish from East Greenland differed from Tampen, northern North Sea, and Bear Island, Barents Sea. A joint model (latent variable model) was used to estimate the effects of covariates on parasite species and identified four parasite species as main source of differences among fishing grounds; namely Chondracanthus nodosus, Anisakis simplex s.s., Hysterothylacium aduncum, and Bothriocephalus scorpii. Due to its high abundance and differences between fishing grounds, Anisakis simplex s.s. was considered as a major biological tag for host stock differentiation. Whilst the sole examination of Anisakis simplex s.s. on a population genetic level is only of limited use, anisakid nematodes (in particular, A. simplex s.s.) can serve as biological tags on a parasite community level. This study confirmed the use of multivariate analyses as a tool to evaluate parasite infra-communities and to identify parasite species that might serve as biological tags. The present study suggests that S. mentella in the northern North Sea and Barents Sea is not sub-structured. PMID:27104735

Copper-stimulated respiration in the unfertilized egg of the Eurasian perch, Perca fluviatilis (L).

PubMed

Akberali, H B; Earnshaw, M J

1984-01-01

The addition of Cu2+ (0.1-1.0 mM) to respiring, unfertilized eggs produced a marked stimulation in the rate of respiration whereas Zn2+ had no effect over the same concentration range. In the absence of Cu2+, temperature had little effect on unfertilized egg respiration but the Cu2+ stimulated respiratory rate showed the more normal response with a Q10 of 1.86 (10-20 degrees C). It appears that perch egg respiration is rate-limited by a physical event and it is suggested that Cu2+ may act by dissipating an oxygen permeability barrier located at the chorion.

Feeding range of age 1+ year Eurasian perch Perca fluviatilis in the Baltic Sea.

PubMed

Ahlbeck Bergendahl, I; Holliland, P B; Hansson, S; Karlöf, O

2017-05-01

Using the widespread Eurasian perch Perca fluviatilis as a model organism, feeding ranges were investigated using stable-isotope ratios (δ 15 N and δ 13 C) and body condition. Differences were found between closely located sampling sites in a littoral area without obvious migration barriers, indicating that individual fish had small feeding ranges. Body condition differences between sampled stations were consistent over 4 years. Such sedentary behaviour is important to consider in, e.g. fisheries management and environmental monitoring, as local catch regulations may be meaningful or geographic stability in sampling locations may reduce noise in data. © 2017 The Fisheries Society of the British Isles.

Field and laboratory investigation of acid effects on largemouth bass, rock bass, black crappie, and yellow perch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eaton, J.G.; Swenson, W.A.; McCormick, J.H.

1992-01-01

One-half of Little Rock Lake, a small seepage lake in north-central Wisconsin, was gradually acidified by additions of sulfuric acid between August 1983 and November 1990. The ambient pH (6.1) of the lake was reduced at successive 2-year intervals to pH 5.6, 5.1, and 4.7. Responses of largemouth bass Micropterus salmoides, rock bass Ambloplites rupestris, black crappie Pomoxis nigromaculatus, and yellow perch Perca flavescens populations to the pH reductions were recorded and compared to the responses of these species during in situ bioassays and laboratory toxicity tests on embryos and larvae. Laboratory results obtained for largemouth bass and rock bassmore » underestimated, black crappie results overestimated, and yellow perch results were similar to effects observed in field studies. In situ bioassays predicted field responses better than did laboratory toxicity tests. Laboratory results showed that monomeric Al concentrations of approximately 50 microgram/l, which were comparable to Al concentrations in the acidified half of the lake, altered low-pH toxicity. Reduced recruitment was observed in field populations at higher pH than that at which adult mortality was observed. The results indicate that laboratory toxicity tests with early life stages may not accurately predict field population responses and that results from laboratory tests should be field-validated whenever possible.« less

Examining the utility of bulk otolith δ13C to describe diet in wild-caught black rockfish Sebastes melanops

USGS Publications Warehouse

von Biela, Vanessa; Newsome, Seth D.; Zimmerman, Christian E.

2015-01-01

Otolith carbon isotope δ13C values may provide temporally resolved diet proxies in fish. If otolith δ13C values reflect diet, isotope values from recent otolith and muscle tissue should correlate and known ontogenetic diet shifts should be reflected in comparisons between otolith material deposited during different life history stages. We analyzed paired otolith and muscle samples for δ13C from black rockfish Sebastes melanops to examine the potential of otoliths to reflect diet in small (200-299 mm fork length) and large (≥300 mm) fish. We found a significant positive regression between δ13C values from recent (~12 mo) otolith material and muscle in large fish, but not in small fish. Within individual otoliths, δ13C values were enriched by ~3‰ in recent otolith edge material compared to age-0 otolith core material and were consistent with known nearshore-offshore gradients in δ13C values at the base of the food web. Bulk otolith δ13C appeared to provide a broad indicator of dietary carbon sources, but variation in metabolism and dissolved inorganic carbon δ13C among and within individuals likely influences otolith δ13C as well and limits precision. Nevertheless, the results are promising and bulk otolith δ13C may be an appropriate tool to examine large trophic and ecosystem level shifts that have occurred concurrently with changes in habitat, commercial fishing, invasive species, climate change, and other direct or indirect human impacts using historic or ancient otoliths. Future studies should continue to consider the utility of bulk otolith δ13C to describe diet in other marine fish using this simple approach.

Reduction in recruitment of white bass in Lake Erie after invasion of white perch

USGS Publications Warehouse

Madenjian, Charles P.; Knight, Roger L.; Bur, Michael; Forney, John L.

2000-01-01

Recruitment to the adult population of white bass Morone chrysops in Lake Erie sharply declined during the early 1980s. To explain this phenomenon, we formulated the following four hypotheses: (1) the biological characteristics of adult spawners changed during the early 1980s, so that the ability to produce eggs decreased; (2) the decrease in phosphorus loadings to Lake Erie during the 1970s resulted in a lower abundance of crustacean zooplankton and thus in reduced survival of age-0 white bass; (3) the increase in the population of adult walleyes Stizostedion vitreum in Lake Erie during the 1970s and 1980s led to reduced survival of age-0 white bass; and (4) establishment of the white perch Morone americana population in Lake Erie during the early 1980s led to reduced survival of the early life stages of white bass. The growth, maturity, and fecundity of adults during the period 1981-1997 were compared with the same characteristics found by earlier studies. The mean length, weight, and condition factors that we calculated were higher than those reported for Lake Erie in 1927-1929 for all age groups examined, and white bass in Lake Erie matured at an earlier age during 1981-1997 than during 1927-1929. Fecundity estimates ranged from 128,897 to 1,049,207 eggs/female and were similar to estimates from other populations. Therefore, the first hypothesis was rejected. With respect to the second hypothesis, zooplankton surveys conducted during 1970 and 1983-1987 indicated that the abundance of crustacean zooplankton in Lake Erie did not change between the two time periods. However, these results were not conclusive because only a single-year survey was conducted before 1980. Based on walleye diet studies and estimates of walleye population size, walleye predation pressure on age-0 white bass in Lake Erie during 1986-1988 was just slightly higher than that during 1979-1981. Thus, such pressure can explain only a minor portion of the reduction in white bass recruitment. To

PERCH in Perspective: What Can It Teach Us About Pneumonia Etiology in Children?

PubMed

Klugman, Keith P; Rodgers, Gail L

2017-06-15

The pneumonia team at the Bill & Melinda Gates Foundation congratulates the Pneumonia Etiology Research for Child Health (PERCH) study on delivering on their grant to collect high-quality data from thousands of children with World Health Organization-defined severe and very severe pneumonia and from controls in 9 diverse sites in 7 low- and middle-income countries. This supplement sets the foundation to understanding this complex study by providing an in-depth description of the study methodology, including discussion of key aspects such as antibiotic pretreatment, chest radiograph interpretation, utility of induced sputum in children, measurement of pathogen density, and use of C-reactive protein, and how these affect pneumonia etiology. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Hawk Eyes II: Diurnal Raptors Differ in Head Movement Strategies When Scanning from Perches

PubMed Central

O'Rourke, Colleen T.; Pitlik, Todd; Hoover, Melissa; Fernández-Juricic, Esteban

2010-01-01

Background Relatively little is known about the degree of inter-specific variability in visual scanning strategies in species with laterally placed eyes (e.g., birds). This is relevant because many species detect prey while perching; therefore, head movement behavior may be an indicator of prey detection rate, a central parameter in foraging models. We studied head movement strategies in three diurnal raptors belonging to the Accipitridae and Falconidae families. Methodology/Principal Findings We used behavioral recording of individuals under field and captive conditions to calculate the rate of two types of head movements and the interval between consecutive head movements. Cooper's Hawks had the highest rate of regular head movements, which can facilitate tracking prey items in the visually cluttered environment they inhabit (e.g., forested habitats). On the other hand, Red-tailed Hawks showed long intervals between consecutive head movements, which is consistent with prey searching in less visually obstructed environments (e.g., open habitats) and with detecting prey movement from a distance with their central foveae. Finally, American Kestrels have the highest rates of translational head movements (vertical or frontal displacements of the head keeping the bill in the same direction), which have been associated with depth perception through motion parallax. Higher translational head movement rates may be a strategy to compensate for the reduced degree of eye movement of this species. Conclusions Cooper's Hawks, Red-tailed Hawks, and American Kestrels use both regular and translational head movements, but to different extents. We conclude that these diurnal raptors have species-specific strategies to gather visual information while perching. These strategies may optimize prey search and detection with different visual systems in habitat types with different degrees of visual obstruction. PMID:20877650

A field and laboratory investigation of acid effects on largemouth bass, rock bass, black crappie, and yellow perch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eaton, J.G.; McCormick, J.H.; Swenson, W.A.

1992-09-01

One-half of Little Rock Lake, a small seepage lake in north-central Wisconsin, was gradually acidified by additions of sulfuric acid between August 1983 and November 1990. The ambient pH (6.1) of the lake was reduced at successive 2-year intervals to pH 5.6, 5.1, and 4.7. Responses of largemouth bass Micropterus salmoides, rock bass Ambloplites rupestris, black crappie Pomoxis nigromaculatus, and yellow perch Perca flavescens populations to the pH reductions were recorded and compared to the responses of these species during in situ bioassays and laboratory toxicity tests on embryos and larvae. Laboratory results obtained for largemouth bass and rock bassmore » underestimated, black crappie results overestimated, and yellow perch results were similar to effects observed in field studies. In situ bioassays predicted field responses better than did laboratory toxicity tests. Laboratory results showed that monomeric Al concentrations of approximately 50 [mu]g/L, which were comparable to Al concentrations in the acidified half of the lake, altered low-pH toxicity. Reduced recruitment was observed in field populations at higher pH than that at which adult mortality was observed. The results indicate that laboratory toxicity tests with early life stages may not accurately predict field population responses and that results from laboratory tests should be field-validated whenever possible. 42 refs., 2 figs., 7 tabs.« less

Ecological carryover effects associated with partial migration in white perch (Morone americana) within the Hudson River Estuary

NASA Astrophysics Data System (ADS)

Gallagher, Brian K.; Piccoli, Philip M.; Secor, David H.

2018-01-01

Partial migration in complex life cycles allows environmental conditions experienced during one life-stage to interact with genetic thresholds and produce divergent spatial behaviors in the next stage. We evaluated partial migration over the entire life cycle of white perch, (Morone americana) within the Hudson River Estuary, combining otolith microchemistry, population demographics and environmental data analysis. Ecological carryover effects were used as a framework to test how environmental variation during the larval period influenced migration behaviors and growth characteristics in subsequent life-stages. Two annual cohorts of juveniles were classified based on whether they persisted in natal habitats (freshwater resident contingent) or dispersed into non-natal habitats (brackish water migratory contingent) as juveniles. The migratory contingent tended to hatch earlier and experience cooler temperatures as larvae, while the availability of zooplankton prey during the larval period appeared to influence growth dynamics before and after metamorphosis. Juvenile migration behaviors were reversible but usually persisted into adulthood. As juveniles, the consequences of partial migration on growth appeared to be modified by river flow, as demonstrated by the influence of a large storm event on feeding conditions in one of the study years. Migratory adults grew faster and attained larger maximum sizes, but may also experience higher rates of mortality. The interplay uncovered between life-stage transitions, conditional migration behaviors and habitat productivity throughout the life cycle shapes white perch population dynamics and will likely play an important role in responses to long-term environmental change.

Oxidative stress, neurotoxicity, and metallothionein (MT) gene expression in juvenile rock fish Sebastes schlegelii under the different levels of dietary chromium (Cr(6+)) exposure.

PubMed

Kim, Jun-Hwan; Kang, Ju-Chan

2016-03-01

Juvenile Sebastes schlegelii were exposed for 4 weeks with the different levels of dietary chromium (Cr(6+)) concentration (0, 30, 60, 120 and 200mg/kg). The superoxide dismutase (SOD) activity, glutathione S-transferase (GST) activity, and glutathione (GSH) level of liver and gill were evaluated after 4 weeks exposure. The SOD and GST activity of liver and gill was significantly increased in the concentration of 240mg/kg after 2 weeks and over 120mg/kg after 4 weeks, whereas a considerable decrease in the concentration of 240mg/kg after 2 weeks and over 120mg/kg after 4 weeks was observed in the GSH levels of liver and gill. In neurotoxicity, AChE activity was significatly inhibited in brain in the concentration of 240mg/kg after 2 weeks and over 60mg/kg after 4 weeks and muscle in the concentration of 240mg/kg after 2 weeks and over 120mg/kg after 4 weeks. Metallothionein (MT) gene in liver was considerably increased over 120mg/kg after 2 weeks and at 30, 120, and 240mg/kg after 4 weeks by dietary chromium exposure. The results indicate that dietary Cr exposure over 120mg/kg can induce substantial alterations in antioxidant responses, AChE activity and MT gene expression. Copyright © 2015 Elsevier Inc. All rights reserved.

Estimation of Hydraulic Properties Influencing Recharge and Contaminant Transport through Complex Vadose Zones by Analyzing Perched Water Data from the 1994 Large-Scale Infiltration Test at the Idaho National Laboratory

NASA Astrophysics Data System (ADS)

Creasey, K. M.; Nimmo, J. R.

2014-12-01

Layers of strong geologic contrast within the vadose zone can control recharge and contaminant transport to underlying aquifers. Above the eastern Snake River Plain Aquifer, multiple sedimentary interbeds are interspersed between fractured basalt. These interbeds have a variety of thicknesses and hydraulic properties, and can impede water flow, which allows perched water to collect on the interbeds. The Large-Scale Infiltration Test (LSIT) of 1994 at the Idaho National Laboratory (INL) maintained a circular pond, 200 meters in diameter, at a constant head for 20 days. Monitoring wells were arranged in circles of different radii around and within the pond, and perched water levels on a major sedimentary interbed, 55 meters below ground surface, were measured over time. Data showed that water formed a mound on the interbed before seeping through the interbed. Such behavior is consistent with a hypothesis of rapid flow through the fractured basalt being impeded by the sedimentary interbed. In 2014, the USGS, in cooperation with the U.S. Department of Energy, used a modified version of a Hantush (1967) equation to model the time-dependent perched water table heights from the LSIT as a function of radial distance from the pond center. The modeled volume change between time-steps and the known inflows to the pond were used in a mass balance to estimate the time-varying volume of water seeping through the interbed. This volume of water, the height of perched water, and the interbed thickness were used in Darcy's Law to estimate the effective saturated hydraulic conductivity of the impeding interbed. Results indicate a slightly higher effective conductivity than laboratory measurements of small core samples taken from the interbed, reflecting the presence of fractures or other heterogeneities that facilitate field-scale flow through the interbed. Applied to other locations, this method can improve estimates of recharge and contaminant transport to underlying aquifers.

Henneguya sp. (Cnidospora:Myxosporida) parasitic in the heart of the bluefish, Pomatomus saltatrix.

PubMed

Meyers, T R; Sawyer, T K; MacLean, S A

1977-10-01

A myxosporidan parasite, Henneguya sp., was discovered in the bulbus and truncus arteriosus of bluefish, Pomatomus saltatrix. Infected fish were captured from the Atlantic Ocean near Montauk Point, Long Island, New York, Raritan Bay, New Jersey, and Chesapeake Bay, Maryland. Comparative features of mature spores showed that they were similar to those of Henneguya sebasta Moser and Love 1975, from the bulbus arteriosus of seven species of California rockfish, Sebastes. Studies on growth stages of the parasite from both host species are necessary before a definite identification of the bluefish parasite can be made.

Expression kinetics of key genes in the early innate immune response to Great Lakes viral hemorrhagic septicemia virus IVb infection in yellow perch (Perca flavescens)

USGS Publications Warehouse

Olson, Wendy; Emmenegger, Eveline; Glenn, Jolene; Simchick, Crystal; Winton, Jim; Goetz, Frederick

2013-01-01

The recently discovered strain of viral hemorrhagic septicemia virus, VHSV-IVb, represents an example of the introduction of an extremely pathogenic rhabdovirus capable of infecting a wide variety of new fish species in a new host-environment. The goal of the present study was to delineate the expression kinetics of key genes in the innate immune response relative to the very early stages of VHSV-IVb infection using the yellow perch (Perca flavescens) as a model. Administration of VHSV-IVb by IP-injection into juvenile yellow perch resulted in 84% cumulative mortality, indicating their high susceptibility to this disease. In fish sampled in the very early stages of infection, a significant up-regulation of Mx gene expression in the liver, as well as IL-1β and SAA activation in the head kidney, spleen, and liver was directly correlated to viral load. The potential down-regulation of Mx in the hematopoietic tissues, head kidney and spleen, may represent a strategy utilized by the virus to increase replication.

[HELMINTHS OF THE COMMON ROACH (RUTILUS RUTILUS LINNAEUS, 1758) AND THE EUROPEAN PERCH (PERCA FLUVIALITIS LINNAEUS, 1758) IN THE LAKE TERKHIIN TSAGAAN (MONGOLIA)].

PubMed

Lebedeva, D I; Mendsaikhan, B; Chantuu, Kh; Jargalmaa, G

2015-01-01

The article provides data about helminthes of the common roach and the European perch in the Lake Terkhiin Tsagaan (Mongolia). Six parasite species were found. Data on the occurrence of the trematode species and larvae of Streptocara crassicauda are obtained for the first time. Species composition of Diplostomum spp. metacercariae parasitizing in fish eyes is updated.

Ocean Fertilization and Ocean Acidification

NASA Astrophysics Data System (ADS)

Cao, L.; Caldeira, K.

2008-12-01

It has been suggested that ocean fertilization could help diminish ocean acidification. Here, we quantitatively evaluate this suggestion. Ocean fertilization is one of several ocean methods proposed to mitigate atmospheric CO2 concentrations. The basic idea of this method is to enhance the biological uptake of atmospheric CO2 by stimulating net phytoplankton growth through the addition of iron to the surface ocean. Concern has been expressed that ocean fertilization may not be very effective at reducing atmospheric CO2 concentrations and may produce unintended environmental consequences. The rationale for thinking that ocean fertilization might help diminish ocean acidification is that dissolved inorganic carbon concentrations in the near-surface equilibrate with the atmosphere in about a year. If ocean fertilization could reduce atmospheric CO2 concentrations, it would also reduce surface ocean dissolved inorganic carbon concentrations, and thus diminish the degree of ocean acidification. To evaluate this line of thinking, we use a global ocean carbon cycle model with a simple representation of marine biology and investigate the maximum potential effect of ocean fertilization on ocean carbonate chemistry. We find that the effect of ocean fertilization on ocean acidification depends, in part, on the context in which ocean fertilization is performed. With fixed emissions of CO2 to the atmosphere, ocean fertilization moderately mitigates changes in ocean carbonate chemistry near the ocean surface, but at the expense of further acidifying the deep ocean. Under the SRES A2 CO2 emission scenario, by year 2100 simulated atmospheric CO2, global mean surface pH, and saturation state of aragonite is 965 ppm, 7.74, and 1.55 for the scenario without fertilization and 833 ppm, 7.80, and 1.71 for the scenario with 100-year (between 2000 and 2100) continuous fertilization for the global ocean (For comparison, pre-industrial global mean surface pH and saturation state of

Variation and accumulation patterns of poly- and perfluoroalkyl substances (PFAS) in European perch (Perca fluviatilis) across a gradient of pristine Swedish lakes.

PubMed

Åkerblom, Staffan; Negm, Nesrin; Wu, Pianpian; Bishop, Kevin; Ahrens, Lutz

2017-12-01

This study assessed variations in the concentrations of poly- and perfluoroalkyl substances (PFAS) in European perch (Perca fluviatilis) in Swedish lakes and the extent to which fish size, age and indicators of fish trophic ecology (δ 15 N and δ 13 C) correlate with the sum of individual PFAS concentrations (ΣPFAS). Fish muscle tissue samples (n=80) were taken from six lakes across Sweden and analysed using solid-liquid extraction followed by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). PFAS levels in the lakes were affected by atmospheric deposition in relatively pristine areas with no direct point source of PFAS in the catchment. PFTeDA, PFUnDA, PFTriDA, PFDoDA, PFDA, PFOS and 6:2 FTSA were detected with a frequency between 68% and 99% and were included in the statistical evaluation. ΣPFAS differed between lakes (ANOVA: F=50.6, p<0.0001): fish from lakes in southern Sweden (lake Gårdsjön, 58°03'N, 12°01'E) showed elevated levels of PFAS, with a maximum ΣPFAS of 3.4ng g -1 wet weight (ww) (mean±SD: 0.99±0.63ng g -1 ww), while the lowest levels were found in lake Björntjärn (0.31±0.08ng g -1 ww) in northern Sweden (63°54'N, 18°51'E). PFOS was most abundant in perch from south-western Sweden, while other long-chain perfluorocarbons (>10 carbon atoms) were relatively more abundant in lakes in northern Sweden. Pearson correlation coefficients indicated that concentrations of PFAS in perch did not show any relation to fish size or age and were negatively correlated with trophic position of the fish (δ 15 N). It was also found that ΣPFAS were negatively correlated with both latitude and altitude. The PFAS data in this study represent national background concentrations in freshwater fish across Swedish lakes. Copyright © 2017 Elsevier B.V. All rights reserved.

A multi-level biological approach to evaluate impacts of a major municipal effluent in wild St. Lawrence River yellow perch (Perca flavescens).

PubMed

Houde, Magali; Giraudo, Maeva; Douville, Mélanie; Bougas, Bérénice; Couture, Patrice; De Silva, Amila O; Spencer, Christine; Lair, Stéphane; Verreault, Jonathan; Bernatchez, Louis; Gagnon, Christian

2014-11-01

The development of integrated ecotoxicological approaches is of great interest in the investigation of global concerns such as impacts of municipal wastewater effluents on aquatic ecosystems. The objective of this study was to investigate the effects of a major wastewater municipal effluent on fish using a multi-level biological approach, from gene transcription and enzyme activities to histological changes. Yellow perch (Perca flavescens) were selected based on their wide distribution, their commercial and recreational importance, and the availability of a customized microarray. Yellow perch were sampled upstream of a major municipal wastewater treatment plant (WWTP) and 4 km and 10 km downstream from its point of discharge in the St. Lawrence River (Quebec, Canada). Concentrations of perfluoroalkyl substances (PFASs), polybrominated diphenyl ethers (PBDEs) and metals/trace elements in whole body homogenates were comparable to those from other industrialized regions of the world. Genomic results indicated that the transcription level of 177 genes was significantly different (p<0.024) between exposed and non-exposed fish. Among these genes, 38 were found to be differentially transcribed at both downstream sites. Impacted genes were associated with biological processes and molecular functions such as immunity, detoxification, lipid metabolism/energy homeostasis (e.g., peroxisome proliferation), and retinol metabolism suggesting impact of WWTP on these systems. Moreover, antioxidant enzyme activities were more elevated in perch collected at the 4 km site. Biomarkers of lipid metabolism, biosynthetic activity, and aerobic capacities were significantly lower (p<0.05) in fish residing near the outfall of the effluent. Histological examination of the liver indicated no differences between sites. Correlations between PFAS, PBDE, and metal/trace element tissue concentrations and markers of peroxisomal proliferation, oxidative stress, and retinoid metabolism were found at

Balancing selection on the number of repeats in the ribosomal intergenic spacer present in naturally occurring yellow perch (Perca flavescens) populations.

PubMed

Bélanger-Lépine, Frédérique; Leung, Christelle; Glémet, Hélène; Angers, Bernard

2018-01-01

The ribosomal intergenic spacer (IGS), responsible for the rate of transcription of rRNA genes, is associated with the growth and fecundity of individuals. A previous study of IGS length variants in a yellow perch (Perca flavescens) population revealed the presence of two predominant alleles differing by 1 kb due to variation in the number of repeat units. This study aims to assess whether length variation of IGS is the result of selection in natural populations. Length variation of IGS and 11 neutral microsatellite loci were assessed in geographically distant yellow perch populations. Most populations displayed the very same IGS alleles; they did not differ in frequencies among populations and the F ST was not significantly different from zero. In contrast, diversity at microsatellite loci was high and differed among populations (F ST = 0.18). Selection test based on F ST identified IGS as a significant outlier from neutral expectations for population differentiation. Heterozygote excess was also detected in one specific cohort, suggesting temporal variation in the selection regime. While the exact mechanism remains to be specified, together the results of this study support the contention that balancing selection is acting to maintain two distinct IGS alleles in natural fish populations.

Benefits of Turbid River Plume Habitat for Lake Erie Yellow Perch (Perca flavescens) Recruitment Determined by Juvenile to Larval Genotype Assignment

PubMed Central

Carreon-Martinez, Lucia B.; Walter, Ryan P.; Johnson, Timothy B.; Ludsin, Stuart A.; Heath, Daniel D.

2015-01-01

Nutrient-rich, turbid river plumes that are common to large lakes and coastal marine ecosystems have been hypothesized to benefit survival of fish during early life stages by increasing food availability and (or) reducing vulnerability to visual predators. However, evidence that river plumes truly benefit the recruitment process remains meager for both freshwater and marine fishes. Here, we use genotype assignment between juvenile and larval yellow perch (Perca flavescens) from western Lake Erie to estimate and compare recruitment to the age-0 juvenile stage for larvae residing inside the highly turbid, south-shore Maumee River plume versus those occupying the less turbid, more northerly Detroit River plume. Bayesian genotype assignment of a mixed assemblage of juvenile (age-0) yellow perch to putative larval source populations established that recruitment of larvae was higher from the turbid Maumee River plume than for the less turbid Detroit River plume during 2006 and 2007, but not in 2008. Our findings add to the growing evidence that turbid river plumes can indeed enhance survival of fish larvae to recruited life stages, and also demonstrate how novel population genetic analyses of early life stages can contribute to determining critical early life stage processes in the fish recruitment process. PMID:25954968

Early life history pelagic exposure profiles of selected commercially important fish species in the Gulf of Alaska

NASA Astrophysics Data System (ADS)

Doyle, Miriam J.; Mier, Kathryn L.

2016-10-01

A synthesis of nearly four decades of ichthyoplankton survey data from the Gulf of Alaska was undertaken to provide the most comprehensive information available on the early life history ecology of five focal species: Pacific Cod (Gadus macrocephalus), Walleye Pollock (Gadus chalcogrammus), Pacific Ocean Perch (Sebastes alutus), Sablefish (Anoplopoma fimbria), and Arrowtooth Flounder (Atheresthes stomias). This analysis of historical data, along with information from published studies, is presented here in the form of ecological reviews of the species during their planktonic phase. The reviews include descriptions of temporal and spatial patterns of exposure to the environment, and interpretation regarding associated sensitivities to environmental forcing. On a temporal scale, patterns in abundance of eggs and larvae are synthesized that characterize seasonal exposure to the pelagic environment, and interannual variation that is presumed to incorporate responses to long-term environmental forcing. Spatial patterns are synthesized to identify horizontal and vertical extent of egg and larval distributions, delineate areas of primary larval habitat, and illuminate egg and larval drift pathways. The observed patterns are discussed with respect to characterizing species early life history strategies, identifying long-term adaptations to the Gulf of Alaska environment, and associated resilience and vulnerability factors that may modulate early life responses to environmental forcing in this region. For each species, gaps in knowledge are identified and are concerned primarily with the period of transition between the larval and juvenile stage, and feeding habits and ecology across seasons, habitats and sub-intervals of early ontogeny. These early life history reviews advance our ecological understanding of the pelagic phase, and fine-tune our focus for the investigation of potential response mechanisms to environmental forcing at appropriate, species-specific temporal

Genetically distinct colour morphs of European perch Perca fluviatilis in Lake Constance differ in susceptibility to macroparasites.

PubMed

Roch, S; Behrmann-Godel, J; Brinker, A

2015-01-21

The unusual yellow-finned morph of European perch Perca fluviatilis found in Lake Constance suffers more severely from macroparasite infections, including the tapeworm Triaenophorus nodulosus and the gill worm Ancyrocephalus percae, than conspecifics elsewhere. Microsatellite analysis of yellow-finned P. fluviatilis and red-finned variant recently discovered in Lake Constance revealed significant genetic differentiation. Red-finned P. fluviatilis and fish with mixed fin colour, suggested backcrosses between red and yellow-finned colour morphs, exhibit better resilience to parasite infection, suggesting that the inability of the yellow-finned morph to reject macroparasites may have a genetic basis. © 2015 The Fisheries Society of the British Isles.

A Southern Bald Eagle perches on a pole at KSC.

NASA Technical Reports Server (NTRS)

2000-01-01

A Southern Bald Eagle perched on top of a utility pole searches the area. About a dozen bald eagles live in the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. The Southern Bald Eagle ranges throughout Florida and along the coasts of California, Texas, Louisiana, and the south Atlantic states. Bald Eagles are listed as endangered in the U.S., except in five states where they are listed as threatened. The number of nesting pairs of the southern race once numbered several thousand; recent estimates are only 350-375. Most of the southern race nest in Florida. Eagles arrive at KSC during late summer and leave for the north in late spring. They move to nest sites in October and November and lay one to three eggs. The young fledge from February to April. The Refuge encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

In vitro storage of unfertilized eggs of the Eurasian perch and its effect on egg viability rates and the occurrence of larval malformations.

PubMed

Samarin, A M; Żarski, D; Palińska-Żarska, K; Krejszeff, S; Blecha, M; Kucharczyk, D; Policar, T

2017-01-01

Ova ageing is the most important factor affecting fish egg quality after ovulation. Long-term storage of fish ova, using cryopreservation and vitrification techniques, has been unsuccessful to date. Instead, short-term in vitro ova storage has been used successfully and optimized in some cultured fish species. In vitro ova storage can drastically improve mass production of larvae and juveniles in the hatcheries by providing the possibility of the synchronous artificial fertilization for different females. To study how long unfertilized eggs of Eurasian perch (Perca fluviatilis L.) can retain their fertilizing ability after stripping, eggs were stored at temperatures of 4°C, 8°C and 12°C for 72 h post-stripping (HPS). The stored eggs of four female perch were separately fertilized at 0 h (i.e. control eggs fertilized before storage) and at 6-hour intervals during the experimental period of 72 h. The embryos reaching the eyed-egg and hatched-larvae stages, eyed-egg mortality and larval malformation rates were recorded as indices of egg quality. The results indicated that the maximum eyed eggs and hatched larvae (86% and 63%, respectively) were observed for eggs fertilized immediately after stripping, whereas the storage of the eggs at 4°C for 48 HPS decreased the eyed-egg and hatched-larvae rates to 46% and 17%, respectively. The use of a higher storage temperature resulted in a more rapid decrease in egg viability: eyed-egg and hatched-larvae rates of 23% and 9%, respectively, were obtained after 48 HPS storage at 8°C and 2% and 1% for eggs stored at 12°C. Eyed-egg mortality and larval malformation rates were not significantly affected by post-stripping ova ageing for at least up to 36 h. Thereafter, both values increased significantly and were measured to be the highest in the most aged ova. The present study demonstrated that stripped Eurasian perch eggs can be stored for at least 12 h at 4°C to 12°C without a significant reduction in their quality.

Vulnerability of Southeast Greenland Glaciers to Warm Atlantic Water From Operation IceBridge and Ocean Melting Greenland Data

NASA Astrophysics Data System (ADS)

Millan, R.; Rignot, E.; Mouginot, J.; Wood, M.; Bjørk, A. A.; Morlighem, M.

2018-03-01

We employ National Aeronautics and Space Administration (NASA)'s Operation IceBridge high-resolution airborne gravity from 2016, NASA's Ocean Melting Greenland bathymetry from 2015, ice thickness from Operation IceBridge from 2010 to 2015, and BedMachine v3 to analyze 20 major southeast Greenland glaciers. The results reveal glacial fjords several hundreds of meters deeper than previously thought; the full extent of the marine-based portions of the glaciers; deep troughs enabling warm, salty Atlantic Water (AW) to reach the glacier fronts and melt them from below; and few shallow sills that limit the access of AW. The new oceanographic and topographic data help to fully resolve the complex pattern of historical ice front positions from the 1930s to 2017: glaciers exposed to AW and resting on retrograde beds have retreated rapidly, while glaciers perched on shallow sills or standing in colder waters or with major sills in the fjords have remained stable.

A Southern Bald Eagle perches on a pole at KSC.

NASA Technical Reports Server (NTRS)

2000-01-01

A Southern Bald Eagle perches on top of a utility pole at Kennedy Space Center. About a dozen bald eagles live in the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. The Southern Bald Eagle ranges throughout Florida and along the coasts of California, Texas, Louisiana, and the south Atlantic states. Bald Eagles are listed as endangered in the U.S., except in five states where they are listed as threatened. The number of nesting pairs of the southern race once numbered several thousand; recent estimates are only 350-375. Most of the southern race nest in Florida. Eagles arrive at KSC during late summer and leave for the north in late spring. They move to nest sites in October and November and lay one to three eggs. The young fledge from February to April. The Refuge encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

A Red-Tailed Hawk perches on a stump at KSC.

NASA Technical Reports Server (NTRS)

2000-01-01

This red-tailed hawk on the roadside at Kennedy Space Center appears to be eyeing the photographer. The red-tailed hawk has a stocky build and broad, rounded wings. Its wide range covers Alaska and Nova Scotia south to Panama. It can frequently be seen perched in a tree at the edge of a meadow, watching for movement in the grass below. It feeds mainly on small rodents. The Refuge encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects. Kennedy Space Center shares a boundary with the Merritt Island National Wildlife Refuge, encompassing 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

An artificial perch to help Snail Kites handle an exotic Apple Snail

USGS Publications Warehouse

Pias, Kyle E.; Welch, Zach C.; Kitchens, Wiley M.

2012-01-01

In the United States, the Snail Kite (Rostrhamus sociabilis plumbeus) is a federally endangered species and restricted to the wetlands of south-central Florida where the current population numbers less than 1,500. The Snail Kite is an extreme dietary specialist, previously feeding almost exclusively on one species of snail, the Florida Apple Snail (Pomacea paludosa). Within the past decade, an exotic species of apple snail, the Island Apple Snail (Pomacea insularum), has become established on lakes in central Florida. Island Apple Snails are larger than the native Florida Apple Snails, and Snail Kites handle the exotic snails less efficiently. Juvenile Snail Kites, in particular, have lower daily energy balances while feeding on Island Apple Snails. An inexpensive, easy-to-construct platform was developed that would provide Snail Kites with a flat, stable surface on which to extract snails. The platform has the potential to reduce the difficulties Snail Kites experience when handling exotic snails, and may benefit the Snail Kite population as a whole. Initial observations indicate that Snail Kites use the platforms frequently, and snails extracted at the platforms are larger than snails extracted at other perches.

Characterisation of the genomes of four putative vesiculoviruses: tench rhabdovirus, grass carp rhabdovirus, perch rhabdovirus and eel rhabdovirus European X.

PubMed

Stone, David M; Kerr, Rose C; Hughes, Margaret; Radford, Alan D; Darby, Alistair C

2013-11-01

The complete coding sequences were determined for four putative vesiculoviruses isolated from fish. Sequence alignment and phylogenetic analysis based on the predicted amino acid sequences of the five main proteins assigned tench rhabdovirus and grass carp rhabdovirus together with spring viraemia of carp and pike fry rhabdovirus to a lineage that was distinct from the mammalian vesiculoviruses. Perch rhabdovirus, eel virus European X, lake trout rhabdovirus 903/87 and sea trout virus were placed in a second lineage that was also distinct from the recognised genera in the family Rhabdoviridae. Establishment of two new rhabdovirus genera, "Perhabdovirus" and "Sprivivirus", is discussed.

Effects of turbidity and prey density on the foraging success of age 0 year yellow perch Perca flavescens.

PubMed

Wellington, C G; Mayer, C M; Bossenbroek, J M; Stroh, N A

2010-05-01

Laboratory experiments were conducted to determine how larval and juvenile yellow perch Perca flavescens respond to changes in prey density when exposed to different levels and types of turbidity (phytoplanktonic or sedimentary). Across prey densities, consumption by P. flavescens tended to be less in phytoplanktonic turbidity compared with sedimentary turbidity. For larvae, this effect was dependent on turbidity level (consumption differed between turbidity types only at high turbidity), while for juveniles the difference with turbidity type was equal across turbidity levels. These results suggest that phytoplankton blooms are detrimental to the ability of late season age 0 year P. flavescens to forage and support the need to control factors leading to excessive phytoplankton growth in lakes.

75 FR 18778 - Safety Zone; Ocean City Air Show 2010, Atlantic Ocean, Ocean City, MD

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-13

...-AA00 Safety Zone; Ocean City Air Show 2010, Atlantic Ocean, Ocean City, MD AGENCY: Coast Guard, DHS... zone on the Atlantic Ocean in the vicinity of Ocean City, Maryland to support the Ocean City Air Show..., 5, and 6, 2010 Ocean City, Maryland will host an air show event on the Atlantic Ocean between Talbot...

76 FR 31235 - Safety Zone; Ocean City Air Show, Atlantic Ocean, Ocean City, MD

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-31

...-AA00 Safety Zone; Ocean City Air Show, Atlantic Ocean, Ocean City, MD AGENCY: Coast Guard, DHS. ACTION... in the vicinity of Ocean City, MD to support the Ocean City Air Show. This action is necessary to provide for the safety of life on navigable waters during the Ocean City Air Show. This action is intended...

OceanSITES: Sustained Ocean Time Series Observations in the Global Ocean.

NASA Astrophysics Data System (ADS)

Weller, R. A.; Gallage, C.; Send, U.; Lampitt, R. S.; Lukas, R.

2016-02-01

Time series observations at critical or representative locations are an essential element of a global ocean observing system that is unique and complements other approaches to sustained observing. OceanSITES is an international group of oceanographers associated with such time series sites. OceanSITES exists to promote the continuation and extension of ocean time series sites around the globe. It also exists to plan and oversee the global array of sites in order to address the needs of research, climate change detection, operational applications, and policy makers. OceanSITES is a voluntary group that sits as an Action Group of the JCOMM-OPS Data Buoy Cooperation Panel, where JCOMM-OPS is the operational ocean observing oversight group of the Joint Commission on Oceanography and Marine Meteorology of the International Oceanographic Commission and the World Meteorological Organization. The way forward includes working to complete the global array, moving toward multidisciplinary instrumentation on a subset of the sites, and increasing utilization of the time series data, which are freely available from two Global Data Assembly Centers, one at the National Data Buoy Center and one at Coriolis at IFREMER. One recnet OceanSITES initiative and several results from OceanSITES time series sites are presented. The recent initiative was the assembly of a pool of temperature/conductivity recorders fro provision to OceanSITES sites in order to provide deep ocean temperature and salinity time series. Examples from specific sites include: a 15-year record of surface meteorology and air-sea fluxes from off northern Chile that shows evidence of long-term trends in surface forcing; change in upper ocean salinity and stratification in association with regional change in the hydrological cycle can be seen at the Hawaii time series site; results from monitoring Atlantic meridional transport; and results from a European multidisciplinary time series site.

78 FR 32556 - Safety Zone; 2013 Ocean City Air Show, Atlantic Ocean; Ocean City, MD

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-31

...-AA00 Safety Zone; 2013 Ocean City Air Show, Atlantic Ocean; Ocean City, MD AGENCY: Coast Guard, DHS... navigable waters of the Atlantic Ocean in the vicinity of Ocean City, MD to support the Ocean City Air Show... June 9, 2013, Ocean City, MD will host an air show event between Talbot Street and 33rd Street over the...

Survival, blood osmolality, and gill morphology of juvenile yellow perch, rock bass, black crappie, and largemouth bass exposed to acidified soft water

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCormick, J.H.; Jensen, K.M.; Leino, R.L.

1989-01-01

When exposed to a range of pH from 7.0 to 4.0 in soft water (1 mg Ca(2+)/L), juvenile rock bass Ambloplites rupestris, black crappie Pomoxis nigromaculatus, and largemouth bass Micropterus salmoides showed a capacity to osmoregulate and survive for up to 30 d at pH 4.5 and above. Juvenile yellow perch Perca flavescens maintained osmoregulatory control through 58 d at pH 5.0. All four species lost osmoregulatory control at pH 4.0, and death of fish ensued within a few days after blood osmolality declined to about 200 mosmol/kg or less (normal values, about 300 mosmol/kg). After 58 d of exposuremore » of pH 4.0, mean blood osmolality of yellow perch was 218 mosmol/kg, and these fish were severely emaciated and moribund. Rock bass, black crappie, and largemouth bass all died by days 29, 16, and 9, respectively, when exposed to pH 4.0. Examination of gills showed progressively increased pathology with longer exposures to lower than normal pH. Among fish exposed to low pH, gill hyperplasia was present most often, but epithelial hypertrophy, chloride-cell proliferation, chloride-cell degeneration, edema, and vacuolization of the tissues also were observed. Morphological changes that were observed in the three centrarchids at pH values above pH 4.0 suggested that gill pathology may be a more sensitive indicator of potentially lethal acid stress than blood osmolality.« less

A Kinetic Study of Accumulation and Elimination of Microcystin-LR in Yellow Perch (Perca Flavescens) Tissue and Implications for Human Fish Consumption

PubMed Central

Dyble, Julianne; Gossiaux, Duane; Landrum, Peter; Kashian, Donna R.; Pothoven, Steven

2011-01-01

Fish consumption is a potential route of human exposure to the hepatotoxic microcystins, especially in lakes and reservoirs that routinely experience significant toxic Microcystis blooms. Understanding the rates of uptake and elimination for microcystins as well as the transfer efficiency into tissues of consumers are important for determining the potential for microcystins to be transferred up the food web and for predicting potential human health impacts. The main objective of this work was to conduct laboratory experiments to investigate the kinetics of toxin accumulation in fish tissue. An oral route of exposure was employed in this study, in which juvenile yellow perch (Perca flavescens) were given a single oral dose of 5 or 20 μg of microcystin-LR (MC-LR) via food and accumulation in the muscle, liver, and tank water were measured over 24 h. Peak concentrations of the water soluble fraction of microcystin were generally observed 8–10 h after dosing in the liver and after 12–16 h in the muscle, with a rapid decline in both tissues by 24 h. Up to 99% of the total recoverable (i.e., unbound) microcystin was measured in the tank water by 16 h after exposure. The relatively rapid uptake and elimination of the unbound fraction of microcystin in the liver and muscle of juvenile yellow perch within 24 h of exposure indicates that fish consumption may not be a major route of human exposure to microcystin, particularly in the Great Lakes. PMID:22363240

78 FR 74079 - Fisheries of the Exclusive Economic Zone Off Alaska; Gulf of Alaska; Proposed 2014 and 2015...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-10

... trend for pollock, Pacific cod, deep-water flatfish, Pacific ocean perch, northern rockfish, shortraker..., shallow-water flatfish, rex sole, arrowtooth flounder, flathead sole, rougheye rockfish, demersal shelf... include the TACs for shallow-water flatfish in the West Yakutat and Southeast Outside Districts of the GOA...

77 FR 15193 - Fisheries of the Exclusive Economic Zone Off Alaska; Gulf of Alaska; Final 2012 and 2013 Harvest...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-14

..., sablefish, deep-water flatfish, rex sole, Pacific ocean perch, northern rockfish, shortraker rockfish... cod, shallow-water flatfish, arrowtooth flounder, flathead sole, ``other rockfish'' in the Eastern GOA...) guideline harvest levels (GHLs) for Pacific cod so that the ABC is not exceeded. The shallow-water flatfish...

78 FR 13161 - Fisheries of the Exclusive Economic Zone Off Alaska; Gulf of Alaska; Final 2013 and 2014 Harvest...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-26

... halibut PSC trawl limits between the trawl gear deep-water and the shallow-water species fishery... for pollock, sablefish, deep-water flatfish, rex sole, Pacific ocean perch, northern rockfish... less than the ABCs for Pacific cod, shallow-water flatfish, arrowtooth flounder, flathead sole, ``other...

50 CFR Table 33 to Part 679 - Annual Apportion of Amendment 80 Species ITAC Between the Amendment 80 and BSAI Trawl Limited...

Code of Federal Regulations, 2011 CFR

2011-10-01

... 90 10 Aleutian Islands Pacific ocean perch 543 All years 98 2 542 2008 95 5 2009 and all future years 90 10 541 2008 95 5 2009 and all future years 90 10 Pacific cod BSAI All years 13.4 N/A Rock sole...

50 CFR Table 33 to Part 679 - Annual Apportion of Amendment 80 Species ITAC Between the Amendment 80 and BSAI Trawl Limited...

Code of Federal Regulations, 2013 CFR

2013-10-01

... 90 10 Aleutian Islands Pacific ocean perch 543 All years 98 2 542 2008 95 5 2009 and all future years 90 10 541 2008 95 5 2009 and all future years 90 10 Pacific cod BSAI All years 13.4 N/A Rock sole...

50 CFR Table 33 to Part 679 - Annual Apportion of Amendment 80 Species ITAC Between the Amendment 80 and BSAI Trawl Limited...

Code of Federal Regulations, 2012 CFR

2012-10-01

... 90 10 Aleutian Islands Pacific ocean perch 543 All years 98 2 542 2008 95 5 2009 and all future years 90 10 541 2008 95 5 2009 and all future years 90 10 Pacific cod BSAI All years 13.4 N/A Rock sole...

50 CFR Table 33 to Part 679 - Annual Apportion of Amendment 80 Species ITAC Between the Amendment 80 and BSAI Trawl Limited...

Code of Federal Regulations, 2014 CFR

2014-10-01

... 90 10 Aleutian Islands Pacific ocean perch 543 All years 98 2 542 2008 95 5 2009 and all future years 90 10 541 2008 95 5 2009 and all future years 90 10 Pacific cod BSAI All years 13.4 N/A Rock sole...

Interaction between vitamins C and E affects their tissue concentrations, growth, lipid oxidation, and deficiency symptoms in yellow perch (Perca flavescens).

PubMed

Lee, Kyeong-Jun; Dabrowski, Konrad

2003-05-01

We have conducted studies with juvenile yellow perch (Perca flavescens) over a period of 20 weeks to address the question of the interaction between water- and lipid-soluble antioxidant vitamins. Fish (2.25+/-0.14 g) were divided into twelve groups, and triplicate groups were fed one of four casein-based, semi-purified diets formulated to contain low or high vitamin E levels of either 5 or 160 mg/kg without or with vitamin C supplementation (250 mg/kg). Diets were designated as -C-E, -C+E, +C-E, or +C+E, respectively. The fish fed the +C+E diet showed significantly higher weight gain, feed intake, and feed efficiency than the groups fed vitamin C-deficient diets. Total ascorbate concentrations of liver were significantly higher in fish fed vitamin C-supplemented diets than in fish fed the vitamin C-deficient diet after 16 and 20 weeks. The liver alpha-tocopherol concentrations were increased by supplemental vitamin C in vitamin E-deficient dietary groups which indicates a sparing or regenerating effect of vitamin C on vitamin E. Fish fed vitamin C-deficient diets (-C-E and -C+E) exhibited severe deficiency symptoms, such as scoliosis, lens cataracts, anorexia, and haemorrhages. The cumulative mortality was significantly higher in the -C-E groups. The thiobarbituric acid-reactive substances value was significantly higher in blood plasma of fish fed a diet unsupplemented with both vitamins. The findings in the present study with yellow perch support the hypothesis that vitamin C regenerates and/or spares vitamin E in vivo.

An update of hydrologic conditions and distribution of selected constituents in water, eastern Snake River Plain aquifer and perched groundwater zones, Idaho National Laboratory, Idaho, emphasis 2009–11

USGS Publications Warehouse

Davis, Linda C.; Bartholomay, Roy C.; Rattray, Gordon W.

2013-01-01

Since 1952, wastewater discharged to infiltration ponds (also called percolation ponds) and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the eastern Snake River Plain (ESRP) aquifer and perched groundwater zones underlying the INL. The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, maintains groundwater monitoring networks at the INL to determine hydrologic trends, and to delineate the movement of radiochemical and chemical wastes in the aquifer and in perched groundwater zones. This report presents an analysis of water-level and water-quality data collected from aquifer, multilevel monitoring system (MLMS), and perched groundwater wells in the USGS groundwater monitoring networks during 2009–11. Water in the ESRP aquifer primarily moves through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer primarily is recharged from infiltration of irrigation water, infiltration of streamflow, groundwater inflow from adjoining mountain drainage basins, and infiltration of precipitation. From March–May 2009 to March–May 2011, water levels in wells generally declined in the northern part of the INL. Water levels generally rose in the central and eastern parts of the INL. Detectable concentrations of radiochemical constituents in water samples from aquifer wells or MLMS equipped wells in the ESRP aquifer at the INL generally decreased or remained constant during 2009–11. Decreases in concentrations were attributed to radioactive decay, changes in waste-disposal methods, and dilution from recharge and underflow. In 2011, concentrations of tritium in groundwater from 50 of 127 aquifer wells were greater than or equal to the reporting level and ranged from 200±60 to 7,000±260 picocuries per liter. Tritium concentrations from one or more discrete zones from four wells equipped with MLMS were greater than or

77 FR 22523 - Safety Zone; 2012 Ocean City Air Show; Atlantic Ocean, Ocean City, MD

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-16

...-AA00 Safety Zone; 2012 Ocean City Air Show; Atlantic Ocean, Ocean City, MD AGENCY: Coast Guard, DHS... the navigable waters of the Atlantic Ocean in Ocean City, MD. This action is necessary to provide for the safety of life on navigable waters during the 2012 Ocean City Air Show. This action is intended to...

Ocean products delivered by the Mercator Ocean Service Department

NASA Astrophysics Data System (ADS)

Crosnier, L.; Durand, E.; Soulat, F.; Messal, F.; Buarque, S.; Toumazou, V.; Landes, V.; Drevillon, M.; Lellouche, J.

2008-12-01

The newly created Service Department at Mercator Ocean is now offering various services for academic and private ocean applications. Mercator Ocean runs operationally ocean forecast systems for the Global and North Atlantic Ocean. These systems are based on an ocean general circulation model NEMO as well as on data assimilation of sea level anomalies, sea surface temperature and temperature and salinity vertical profiles. Three dimensional ocean fields of temperature, salinity and currents are updated and available weekly, including analysis and 2 weeks forecast fields. The Mercator Ocean service department is now offering a wide range of ocean derived products. This presentation will display some of the various products delivered in the framework of academic and private ocean applications: " Monitoring of the ocean current at the surface and at depth in several geographical areas for offshore oil platform, for offshore satellite launch platform, for transatlantic sailing or rowing boat races. " Monitoring of ocean climate indicators (Coral bleaching...) for marine reserve survey; " Monitoring of upwelling systems for fisheries; " Monitoring of the ocean heat content for tropical cyclone monitoring. " Monitoring of the ocean temperature/salinity and currents to guide research vessels during scientific cruises. The Mercator Ocean products catalogue will grow wider in the coming years, especially in the framework of the European GMES MyOcean project (FP7).

Histopathology and the inflammatory response of European perch, Perca fluviatilis muscle infected with Eustrongylides sp. (Nematoda).

PubMed

Dezfuli, Bahram S; Manera, Maurizio; Lorenzoni, Massimo; Pironi, Flavio; Shinn, Andrew P; Giari, Luisa

2015-04-15

The European perch, Perca fluviatilis L. is a common paratenic host of dioctophymatid nematodes belonging to the genus Eustrongylides. In this host, once infected oligochaetes, which serve as the first intermediate host, are ingested, Eustrongylides migrates through the intestine and is frequently encountered within the musculature, free within the body cavity, or encapsulated on the viscera. The current study details the first Italian record of Eustrongylides sp. with larvae reported in the muscle of P. fluviatilis. Uninfected and nematode-infected muscle tissues of perch were fixed and prepared for histological evaluation and electron microscopy. Some sections were subjected to an indirect immunohistochemical method using anti-PCNA, anti-piscidin 3 and anti-piscidin 4 antibodies. A total of 510 P. fluviatilis (TL range 15-25 cm) from Lake Trasimeno, Perugia were post-mortemed; 31 individuals had encysted nematode larvae within their musculature (1-2 worms fish(-1)). Histologically, larvae were surrounded by a capsule with an evident acute inflammatory reaction. Muscle degeneration and necrosis extending throughout the sarcoplasm, sarcolemmal basal lamina, endomysial connective tissue cells and capillaries was frequently observed. Within the encapsulating reaction, macrophage aggregates (MAs) were seen. Immunohistochemical staining with the proliferating cell nuclear antigen (PCNA) revealed numerous PCNA-positive cells within the thickness of the capsule and in the immediate vicinity surrounding Eustrongylides sp. larvae (i.e. fibroblasts and satellite cells), suggesting a host response had been initiated to repair the nematode-damaged muscle. Mast cells (MCs) staining positively for piscidin 3, were demonstrated for the first time in response to a muscle-infecting nematode. The piscidin 3 positive MC's were seen principally in the periphery of the capsule surrounding the Eustrongylides sp. larva. A host tissue response to Eustrongylides sp. larvae infecting the

Ancient DNA analysis of Indigenous rockfish use on the Pacific Coast: Implications for marine conservation areas and fisheries management.

PubMed

Rodrigues, Antonia T; McKechnie, Iain; Yang, Dongya Y

2018-01-01

Rockfish (Sebastes spp.) are a common marine fish in nearshore and continental shelf environments in the North Pacific Ocean. They are frequently identified in coastal archaeological sites in western North America; however, the morphological similarity of rockfish species limits conventional zooarchaeological identifications to the genus level. This study applies ancient DNA analysis to 96 archaeological rockfish specimens from four sites on separate islands in an archipelago on western Vancouver Island, British Columbia, Canada. Two of the archaeological sites are located within a marine protected area specifically designed to facilitate the recovery of inshore rockfish populations; two sites are located outside this boundary and remain subject to considerable fishing pressure. Using mitochondrial 16S and control region DNA sequences, we identify at least twelve different rockfish species utilized during the past 2,500 years. Identification of rockfish at closely spaced and contemporaneously occupied sites confirms that a variety of Sebastes species were consistently exploited at each site, with more exposed areas having a higher number of species present. Identification results indicate that four of the twelve species did not occur within the conservation area boundary and, instead, were found in sites where commercial and recreational fishing continues to be permitted. This study demonstrates that ancient DNA identifications of archaeological assemblages can complement and expand perspective on modern day fisheries conservation and management in this National Park Reserve and First Nations ancestral territory.

Safety of oxytetracycline (Terramycin TM-100F) administered in feed to hybrid striped bass, walleyes, and yellow perch

USGS Publications Warehouse

Gaikowski, M.P.; Wolf, J.C.; Schleis, S.M.; Gingerich, W.H.

2003-01-01

Oxytetracycline (Terramycin TM-100F, a medicated premix containing oxytetracycline at 220 g/kg) is approved in the United States to control certain systemic bacterial diseases of salmon and catfish when fed at a rate of 55-82.5 mg per kilogram of bodyweight per day for 10 d. Although oxytetracycline may also control certain systemic bacterial infections in coolwater or scaled warmwater fish, no safety data for such species are available. Our objective was to determine the safety of oxytetracycline administered in feed at nominal doses of 0, 82.5, 248, or 413 mg??kg-1??d-1 to yellow perch Perca flavescens and hybrid striped bass (striped bass Morone saxatilis x white bass M. chrysops) for 10 d and to walleye Sander vitreus (formerly Stizostedion vitreum) for 20 d. Yellow perch and hybrid striped bass consumed 50% to 100% of the diet, whereas walleye feed consumption was occasionally less than 50% of the diet. Feed or fecal material was present in the gastrointestinal tract of all necropsied walleyes except for one control fish. The single growth effect was that hybrid striped bass offered a nominal dose of 413 mg??kg-1??d-1 were significantly smaller than untreated controls. Oxytetracycline-related histopathological findings were limited to walleyes and were of low severity. The histopathological findings included decreased hematopoietic-lymphopoietic (H&L) tissue in the anterior kidneys, diffuse hyperplasia of the gill filament epithelium, and a decreased prevalence of fish with eosinophilic droplets in their renal tubular epithelial cells. Although the incidence of decreased H&L tissue tended to increase in proportion to oxytetracycline dose, this finding was statistically significant only for fish that received a nominal dose of 413 mg??kg-1??d-1. Given the pathogenicity of the types of bacteria that are controlled by oxytetracycline treatment and the long history of its use in major aquaculture species, the relative risk of the minor oxytetracycline

Opportunistic disease in yellow perch in response to decadal changes in the chemistry of oil sands-affected waters.

PubMed

Hogan, Natacha S; Thorpe, Karen L; van den Heuvel, Michael R

2018-03-01

Oil sands-affected water from mining must eventually be incorporated into the reclaimed landscape or treated and released. However, this material contains petrogenic organic compounds, such as naphthenic acids and traces of polycyclic aromatic hydrocarbons. This has raised concerns for impacts of oil sands process-affected waters on the heath of wildlife and humans downstream of receiving environments. The objective of this study was to evaluate the temporal association of disease states in fish with water chemistry of oil sands-affected waters over more than a decade and determine the pathogens associated with disease pathologies. Yellow perch (Perca flavescens) captured from nearby lakes were stocked into two experimental ponds during 1995-1997 and 2008-2010. South Bison Pond is a drainage basin that has received unextracted oil sands-contaminated material. Demonstration Pond is a constructed pond containing mature fine tailings capped with fresh water. Two disease pathologies, fin erosion for which a suspected bacterial pathogen (Acinetobacter Iwoffi) is identified, and lymphocystis (confirmed using a real-time PCR) were associated with oil sands-affected water exposure. From 1995 to 1997 pathologies were most prevalent in the South Bison Pond; however, from 2008 to 2009, disease was more frequently observed in the Demonstration Pond. CYP1A activity was 3-16 fold higher in fish from experimental ponds as compared to reference populations and this pattern was consistent across all sampling years. Bile fluorescence displayed a gradient of exposure with experimental ponds being elevated over local perch populations. Naphthenic acids decreased in the Bison Pond from approximately 12 mg/L to <4 mg/L while naphthenic acids increased in the Demonstration Pond from 6 mg/L to 12 mg/L due to tailings densification. Temporal changes in naphthenic acid levels, CYP1A activity and bile fluorescent metabolites correlate positively with incidence of disease pathologies

50 CFR Table 2a to Part 679 - Species Codes: FMP Groundfish

Code of Federal Regulations, 2014 CFR

2014-10-01

.... polyspinis) 136 Pacific Ocean Perch (S. alutus) 141 Pygmy (S. wilsoni) 179 Quillback (S. maliger) 147... Alaska plaice 133 Arrowtooth 121 Bering 116 Kamchatka 117 Starry 129 Octopus, North Pacific 870 Pacific...) 710 Sculpins 160 SHARKS Other (if salmon, spiny dogfish or Pacific sleeper shark—use specific species...

50 CFR Table 2a to Part 679 - Species Codes: FMP Groundfish

Code of Federal Regulations, 2013 CFR

2013-10-01

.... polyspinis) 136 Pacific Ocean Perch (S. alutus) 141 Pygmy (S. wilsoni) 179 Quillback (S. maliger) 147... Alaska plaice 133 Arrowtooth 121 Bering 116 Kamchatka 117 Starry 129 Octopus, North Pacific 870 Pacific...) 710 Sculpins 160 SHARKS Other (if salmon, spiny dogfish or Pacific sleeper shark—use specific species...

50 CFR Table 2a to Part 679 - Species Codes: FMP Groundfish

Code of Federal Regulations, 2012 CFR

2012-10-01

.... polyspinis) 136 Pacific Ocean Perch (S. alutus) 141 Pygmy (S. wilsoni) 179 Quillback (S. maliger) 147... Alaska plaice 133 Arrowtooth 121 Bering 116 Kamchatka 117 Starry 129 Octopus, North Pacific 870 Pacific...) 710 Sculpins 160 SHARKS Other (if salmon, spiny dogfish or Pacific sleeper shark—use specific species...

Oceanic oxygenation events in the anoxic Ediacaran ocean.

PubMed

Sahoo, S K; Planavsky, N J; Jiang, G; Kendall, B; Owens, J D; Wang, X; Shi, X; Anbar, A D; Lyons, T W

2016-09-01

The ocean-atmosphere system is typically envisioned to have gone through a unidirectional oxygenation with significant oxygen increases in the earliest (ca. 635 Ma), middle (ca. 580 Ma), or late (ca. 560 Ma) Ediacaran Period. However, temporally discontinuous geochemical data and the patchy metazoan fossil record have been inadequate to chart the details of Ediacaran ocean oxygenation, raising fundamental debates about the timing of ocean oxygenation, its purported unidirectional rise, and its causal relationship, if any, with the evolution of early animal life. To better understand the Ediacaran ocean redox evolution, we have conducted a multi-proxy paleoredox study of a relatively continuous, deep-water section in South China that was paleogeographically connected with the open ocean. Iron speciation and pyrite morphology indicate locally euxinic (anoxic and sulfidic) environments throughout the Ediacaran in this section. In the same rocks, redox sensitive element enrichments and sulfur isotope data provide evidence for multiple oceanic oxygenation events (OOEs) in a predominantly anoxic global Ediacaran-early Cambrian ocean. This dynamic redox landscape contrasts with a recent view of a redox-static Ediacaran ocean without significant change in oxygen content. The duration of the Ediacaran OOEs may be comparable to those of the oceanic anoxic events (OAEs) in otherwise well-oxygenated Phanerozoic oceans. Anoxic events caused mass extinctions followed by fast recovery in biologically diversified Phanerozoic oceans. In contrast, oxygenation events in otherwise ecologically monotonous anoxic Ediacaran-early Cambrian oceans may have stimulated biotic innovations followed by prolonged evolutionary stasis. © 2016 John Wiley & Sons Ltd.

Reconsidering Volcanic Ocean Island Hydrology: Recent Geophysical and Drilling Results

NASA Astrophysics Data System (ADS)

Thomas, D. M.; Pierce, H. A.; Lautze, N. C.

2017-12-01

Recent results of geophysical surveys and exploratory drilling in Hawaii have suggested that Hawaii's hydrogeology may be more complex than has been generally recognized. Instead of a more-or-less homogeneous pile of highly permeable eruptive basalts that are intermittently punctuated by volcanic dikes confined to calderas and rift zones, we are finding that dike compartmentalization is occurring outside of recognized rift zones, leading to significantly higher volumes of stored groundwater within the island. Analysis of recent geophysical surveys have shown local water table elevations that are substantially higher than can be accounted for by the high hydraulic conductivities of Hawaiian basalts. Recent diamond wireline drilling results have also shown that sub-horizontal variations in permeability, associated with significant changes in eruptive character (e.g. explosive vs effusive activity) are acting as significant perching and confining bodies over significant aerial extents and suggest that these features also contribute to increased storage of recharge. Not only is storage much higher than previously assumed, these features appear to impact subsurface groundwater flow in ways that are not accounted for in traditional methods of computing sustainable yields for near shore aquifers: where buried confining formations extend to depths well below sea level, higher elevation recharge is being intercepted and diverted to deep submarine groundwater discharge well below depths that are typically investigated or quantified. We will provide a summary of the recent geophysical survey results along with a revised conceptual model for groundwater circulation within volcanic ocean islands.

Individuals' diet diversity influences gut microbial diversity in two freshwater fish (threespine stickleback and Eurasian perch)

PubMed Central

Bolnick, Daniel I; Snowberg, Lisa K; Hirsch, Philipp E; Lauber, Christian L; Knight, Rob; Caporaso, J Gregory; Svanbäck, Richard; Post, David

2014-01-01

Vertebrates' diets profoundly influence the composition of symbiotic gut microbial communities. Studies documenting diet-microbiota associations typically focus on univariate or categorical diet variables. However, in nature individuals often consume diverse combinations of foods. If diet components act independently, each providing distinct microbial colonists or nutrients, we expect a positive relationship between diet diversity and microbial diversity. We tested this prediction within each of two fish species (stickleback and perch), in which individuals vary in their propensity to eat littoral or pelagic invertebrates or mixtures of both prey. Unexpectedly, in most cases individuals with more generalised diets had less diverse microbiota than dietary specialists, in both natural and laboratory populations. This negative association between diet diversity and microbial diversity was small but significant, and most apparent after accounting for complex interactions between sex, size and diet. Our results suggest that multiple diet components can interact non-additively to influence gut microbial diversity. PMID:24847735

Polychlorinated biphenyls in adult black bass and yellow perch were not associated with their reproductive success in the upper Hudson River, New York, USA.

PubMed

Maceina, Michael J; Sammons, Steven M

2013-07-01

Although production and use of polychlorinated biphenyls (PCBs) ceased nearly 35 yr ago, questions still remain concerning the potential chronic effects these compounds may have on wild fish, including their reproductive success. In the upper Hudson River, New York, USA, fish were exposed to PCBs primarily from 2 manufacturing plants located approximately 320 km upstream of New York City, New York, from the 1940s to 1977. The authors collected yellow perch (Perca flavescens), smallmouth bass (Micropterus dolomieu), and largemouth bass (M. salmoides) using electrofishing, measured PCBs in these adults, and estimated abundance and size of their offspring at age 1 yr (age-1 fish). Fish were collected annually from 2004 to 2009 from 1 control site upstream of the PCB discharge sites and from 2 sites downstream from where PCBs were released. These sites (pools) are separated by a series of dams, locks, and canals. Muscle tissue wet weight PCB and lipid-based PCB concentrations in adults in the 2 PCB exposure pools averaged approximately 1 to 3 µg/g and 100 to 500 µg/g, respectively. Age-1 abundances were not related to adult PCB concentrations but were inversely related to river flow. Size of age-1 fish was slightly greater at the PCB-exposure sites. Levels of PCBs in yellow perch, largemouth bass, and smallmouth bass in the upper Hudson River did not impair or reduce recruitment or reproductive success. Copyright © 2013 SETAC.

Fisheries Education: From the Great Lakes to the Sea.

ERIC Educational Resources Information Center

Fortner, Rosanne; Mayer, Victor J.

1980-01-01

Described are investigations related to fisheries education developed by the Ohio Sea Grant Education Office as a part of a series of Oceanic Education Activities for Great Lake Schools. The investigations discussed are "Yellow Perch in Lake Erie," which concerns fisheries management, and "It's Everyone's Sea: Or Is It," which…

Early life history of the yellow perch, Perca flavescens (Mitchill), in the Red Lakes, Minnesota

USGS Publications Warehouse

Pycha, Richard L.; Smith, Lloyd L.

1955-01-01

The early life history of the yellow perch, an important commercial species in the Red Lakes, Minnesota, has been studied with special reference to length at scale formation, growth rate during first season of life, and food habits as they relate to growth and survival. Scales are fully imbricated in the area of 12th to 14th lateral line scales at 24 millimeters total length. There is a wide annual varition in first season's growth which is not correlated with growth in older fish. Body-scale relationship is rectilinear from 24 to 280 millimeters. Length-weight relationship during the first year is expressed by the equation W = 0.6198 × 10−5 L3.1251 which is very similar to that describing the relationship in later years. Stomach analysis indicates food is primarily plankton but in some seasons fish may be strongly dependent on bottom forms. Variations in food availability appear to be associated with changes in growth and may have a major influence on survival.

Measuring Ocean Literacy: What teens understand about the ocean using the Survey of Ocean Literacy and Engagement (SOLE)

NASA Astrophysics Data System (ADS)

Greely, T. M.; Lodge, A.

2009-12-01

Ocean issues with conceptual ties to science and global society have captured the attention, imagination, and concern of an international audience. Climate change, over fishing, marine pollution, freshwater shortages and alternative energy sources are a few ocean issues highlighted in our media and casual conversations. The ocean plays a role in our life in some way everyday, however, disconnect exists between what scientists know and the public understands about the ocean as revealed by numerous ocean and coastal literacy surveys. While the public exhibits emotive responses through care, concern and connection with the ocean, there remains a critical need for a baseline of ocean knowledge. However, knowledge about the ocean must be balanced with understanding about how to apply ocean information to daily decisions and actions. The present study analyzed underlying factors and patterns contributing to ocean literacy and reasoning within the context of an ocean education program, the Oceanography Camp for Girls. The OCG is designed to advance ocean conceptual understanding and decision making by engagement in a series of experiential learning and stewardship activities from authentic research settings in the field and lab. The present study measured a) what understanding teens currently hold about the ocean (content), b) how teens feel toward the ocean environment (environmental attitudes and morality), and c) how understanding and feelings are organized when reasoning about ocean socioscientific issues (e.g. climate change, over fishing, energy). The Survey of Ocean Literacy and Engagement (SOLE), was used to measure teens understanding about the ocean. SOLE is a 57-item survey instrument aligned with the Essential Principles and Fundamental Concepts of Ocean Literacy (NGS, 2007). Rasch analysis was used to refine and validate SOLE as a reasonable measure of ocean content knowledge (reliability, 0.91). Results revealed that content knowledge and environmental

The effects of a perch, dust bath, and nest box, either alone or in combination as used in furnished cages, on the welfare of laying hens.

PubMed

Barnett, J L; Tauson, R; Downing, J A; Janardhana, V; Lowenthal, J W; Butler, K L; Cronin, G M

2009-03-01

This experiment examined the welfare-related effects of individual furniture items alone or in combination in a factorial experiment using Hy-Line Brown hens housed in 8-bird furnished cages. Welfare was assessed during two 8-wk sampling periods commencing at 29 and 59 wk of age. Measurement of stress, immunology, feather, foot and claw condition, and behavior were taken, and bone strength was measured at the end of the experiment. With the exception of the positive effects of a perch on bone strength, any effects of furniture items were relatively small, even though the furniture was extensively used. Although there were changes in behavior and small changes in feather, foot, and claw condition, it is unclear whether these changes have any meaningful implications for welfare. In this experiment there were 2 additional external control treatments for a small study that examined the effects of increasing space per bird (8 birds in single- and double-width cages) and the effects of group size (8 and 16 birds in double-width cages); using similar methodologies, these treatments showed differences in egg corticosterone concentrations and evidence of immunosuppression. Together, these data suggest that although furniture when present was well-used, any effects of furniture on hen welfare measured by physical and physiological traits, other than the benefit of a perch on bone strength, were smaller than effects of group size and space allowance.

Genetic variability and glacial origins of yellow perch (Perca flavescens) in North America

USGS Publications Warehouse

Todd, Thomas N.; Hatcher, Charles O.

1993-01-01

Starch–gel electrophoresis was used to analyze muscle and liver tissue for variation in 13 enzymes representing 31 presumptive loci in yellow perch (Perca flavescens) from 13 localities scattered throughout the natural geographic range of the species in North America. Ten loci were polymorphic, but only three, alcohol dehydrogenase (ADH-1*), glucose-6-phosphate isomerase (GPI-1*), and phosphoglucomutase (PGM-2*), exhibited polymorphisms at relatively high frequencies across localities. Western populations were fixed for one allele at ADH-1*, eastern populations were fixed for another allele, and populations from intermediate locations in Lake Ontario and Pennsylvania had both alleles. The distributions of alleles at GPI-1* and PGM-2*were similar to that of ADH-1*, exhibiting strong differences between eastern and western populations, although the delineation was not as clear. Western populations were much less variable than eastern populations, and the distribution of alleles indicated that the two groups were derived from Mississippi and Atlantic glacial refugia. Populations near the physiographic discontinuity between the Mississippi and Atlantic drainages in western New York and Pennsylvania exhibited an admixture of typically western and eastern alleles. Such observations are consistent with the mixed faunal history of the region and limited postglacial dispersal of western and eastern populations across the boundary.

Transcriptional profiling, molecular cloning, and functional analysis of C1 inhibitor, the main regulator of the complement system in black rockfish, Sebastes schlegelii.

PubMed

Nilojan, Jehanathan; Bathige, S D N K; Thulasitha, W S; Kwon, Hyukjae; Jung, Sumi; Kim, Myoung-Jin; Nam, Bo-Hye; Lee, Jehee

2018-04-01

C1-inhibitor (C1inh) plays a crucial role in assuring homeostasis and is the central regulator of the complement activation involved in immunity and inflammation. A C1-inhibitor gene from Sebastes schlegelii was identified and designated as SsC1inh. The identified genomic DNA and cDNA sequences were 6837 bp and 2161 bp, respectively. The genomic DNA possessed 11 exons, interrupted by 10 introns. The amino acid sequence possessed two immunoglobulin-like domains and a serpin domain. Multiple sequence alignment revealed that the serpin domain of SsC1inh was highly conserved among analyzed species where the two immunoglobulin-like domains showed divergence. The distinctiveness of teleost C1inh from other homologs was indicated by the phylogenetic analysis, genomic DNA organization, and their extended N-terminal amino acid sequences. Under normal physiological conditions, SsC1inh mRNA was most expressed in the liver, followed by the gills. The involvement of SsC1inh in homeostasis was demonstrated by modulated transcription profiles in the liver and spleen upon pathogenic stress by different immune stimulants. The protease inhibitory potential of recombinant SsC1inh (rSsC1inh) and the potentiation effect of heparin on rSsC1inh was demonstrated against C1esterase and thrombin. For the first time, the anti-protease activity of the teleost C1inh against its natural substrates C1r and C1s was proved in this study. The protease assay conducted with recombinant black rockfish C1r and C1s proteins in the presence or absence of rSsC1inh showed that the activities of both proteases were significantly diminished by rSsC1inh. Taken together, results from the present study indicate that SsC1inh actively plays a significant role in maintaining homeostasis in the immune system of black rock fish. Copyright © 2018. Published by Elsevier Ltd.

Should Controls With Respiratory Symptoms Be Excluded From Case-Control Studies of Pneumonia Etiology? Reflections From the PERCH Study

PubMed Central

Hammitt, Laura L.; Deloria Knoll, Maria; Baggett, Henry C.; Brooks, W. Abdullah; Howie, Stephen R. C.; Kotloff, Karen L.; Levine, Orin S.; Madhi, Shabir A.; Murdoch, David R.; Scott, J. Anthony G.; Thea, Donald M.; Driscoll, Amanda J.; Karron, Ruth A.; Park, Daniel E.; Prosperi, Christine; Zeger, Scott L.; O’Brien, Katherine L.; Feikin, Daniel R.; O’Brien, Katherine L.; Levine, Orin S.; Knoll, Maria Deloria; Feikin, Daniel R.; DeLuca, Andrea N.; Driscoll, Amanda J.; Fu, Wei; Hammitt, Laura L.; Higdon, Melissa M.; Kagucia, E. Wangeci; Karron, Ruth A.; Li, Mengying; Park, Daniel E.; Prosperi, Christine; Wu, Zhenke; Zeger, Scott L.; Watson, Nora L.; Crawley, Jane; Murdoch, David R.; Brooks, W. Abdullah; Endtz, Hubert P.; Zaman, Khalequ; Goswami, Doli; Hossain, Lokman; Jahan, Yasmin; Ashraf, Hasan; Howie, Stephen R. C.; Ebruke, Bernard E.; Antonio, Martin; McLellan, Jessica; Machuka, Eunice; Shamsul, Arifin; Zaman, Syed M.A.; Mackenzie, Grant; Scott, J. Anthony G.; Awori, Juliet O.; Morpeth, Susan C.; Kamau, Alice; Kazungu, Sidi; Kotloff, Karen L.; Tapia, Milagritos D.; Sow, Samba O.; Sylla, Mamadou; Tamboura, Boubou; Onwuchekwa, Uma; Kourouma, Nana; Toure, Aliou; Madhi, Shabir A.; Moore, David P.; Adrian, Peter V.; Baillie, Vicky L.; Kuwanda, Locadiah; Mudau, Azwifarwi; Groome, Michelle J.; Baggett, Henry C.; Thamthitiwat, Somsak; Maloney, Susan A.; Bunthi, Charatdao; Rhodes, Julia; Sawatwong, Pongpun; Akarasewi, Pasakorn; Thea, Donald M.; Mwananyanda, Lawrence; Chipeta, James; Seidenberg, Phil; Mwansa, James; wa Somwe, Somwe; Kwenda, Geoffrey

2017-01-01

Abstract Many pneumonia etiology case-control studies exclude controls with respiratory illness from enrollment or analyses. Herein we argue that selecting controls regardless of respiratory symptoms provides the least biased estimates of pneumonia etiology. We review 3 reasons investigators may choose to exclude controls with respiratory symptoms in light of epidemiologic principles of control selection and present data from the Pneumonia Etiology Research for Child Health (PERCH) study where relevant to assess their validity. We conclude that exclusion of controls with respiratory symptoms will result in biased estimates of etiology. Randomly selected community controls, with or without respiratory symptoms, as long as they do not meet the criteria for case-defining pneumonia, are most representative of the general population from which cases arose and the least subject to selection bias. PMID:28575354

Ocean science. Enhanced: internal tides and ocean mixing.

PubMed

Garrett, Chris

2003-09-26

Recent satellite and in situ observations have shown that at ocean ridges and other seafloor topographic features, a substantial amount of energy is transferred from the main ocean tides into "internal tides." In his Perspective, Garrett explains how these internal waves with tidal periods propagate through the density-stratified deep ocean and eventually break down into turbulence. The resulting mixing affects ocean stratification and ocean circulation. It thus influences climate as well as biological production. The energy for the internal tides is derived from the rotational energy of the Earth-Moon system changes of the length of the day and the distance to the Moon.

Trends in late Maastrichtian calcareous nannofossil distribution patterns, Western North Atlantic margin

USGS Publications Warehouse

,

2002-01-01

First and last occurrences of several Maastrichtian calcareous nannofossil species are shown to be diachronous across paleodepth and paleoenvironment using the graphic correlation method. Calcareous nannofossil assemblages examined from eleven cores from a deep- to shallow-water transect along the eastern United States Atlantic margin document that the first occurrence of Micula murus (Martini 1961) Bukry 1973 is diachronous, appearing 2.0 million years earlier in open ocean sites than in shallow marine sites. The first occurrence (FO) of Lithraphidites kennethii Perch-Nielsen 1984 is also nonsynchronous, appearing in the deep ocean before its FO in neritic waters. The last occurrence (LO) of L. praequadratus Roth 1978 is diachronous across paleodepth, going locally extinct first in deeper water. The LO of Watznaueria bybelliae Self-Trail 1999 is also diachronous, going locally extinct first in shallow-water settings. Ceratolithoides amplector Burnett 1997, C. pricei Burnett 1997, C. self-trailiae Burnett 1997, C. ultimus Burnett 1997, Cribrocorona gallica (Stradner 1963) Perch-Nielsen 1973. Micula praemurus (Bukry 1973) Stradner and Steinmetz 1984, Pseudomicula quadratus Perch-Nielsen et al. 1978, and Semihololithus spp. are present consistently in common to frequent abundances in ODP holes 1050C and 1052E on the Blake Nose, but they are rare or absent from neritic sections in Coastal Plain cores. It is apparent that these species flourished in an open ocean setting, suggesting that differences in assemblage abundance and diversity between deep ocean and nearshore areas were controlled by paleoceanographic factors. These species are not used for biostratigraphy, but may be useful indicators of open ocean conditions. The line of correlation (LOC) for nine Coastal Plain cores clearly defines the Cretaceous-Tertiary (K/T) boundary unconformity at the top of the Maastrichtian section (Peedee Formation) and the Campanian-Maastrichtian (C/M) unconformity at the base of

Studying ocean acidification in the Arctic Ocean

USGS Publications Warehouse

Robbins, Lisa

2012-01-01

The U.S. Geological Survey (USGS) partnership with the U.S. Coast Guard Ice Breaker Healey and its United Nations Convention Law of the Sea (UNCLOS) cruises has produced new synoptic data from samples collected in the Arctic Ocean and insights into the patterns and extent of ocean acidification. This framework of foundational geochemical information will help inform our understanding of potential risks to Arctic resources due to ocean acidification.

Association of C-Reactive Protein With Bacterial and Respiratory Syncytial Virus-Associated Pneumonia Among Children Aged <5 Years in the PERCH Study.

PubMed

Higdon, Melissa M; Le, Tham; O'Brien, Katherine L; Murdoch, David R; Prosperi, Christine; Baggett, Henry C; Brooks, W Abdullah; Feikin, Daniel R; Hammitt, Laura L; Howie, Stephen R C; Kotloff, Karen L; Levine, Orin S; Scott, J Anthony G; Thea, Donald M; Awori, Juliet O; Baillie, Vicky L; Cascio, Stephanie; Chuananon, Somchai; DeLuca, Andrea N; Driscoll, Amanda J; Ebruke, Bernard E; Endtz, Hubert P; Kaewpan, Anek; Kahn, Geoff; Karani, Angela; Karron, Ruth A; Moore, David P; Park, Daniel E; Rahman, Mohammed Ziaur; Salaudeen, Rasheed; Seidenberg, Phil; Somwe, Somwe Wa; Sylla, Mamadou; Tapia, Milagritos D; Zeger, Scott L; Deloria Knoll, Maria; Madhi, Shabir A

2017-06-15

Lack of a gold standard for identifying bacterial and viral etiologies of pneumonia has limited evaluation of C-reactive protein (CRP) for identifying bacterial pneumonia. We evaluated the sensitivity and specificity of CRP for identifying bacterial vs respiratory syncytial virus (RSV) pneumonia in the Pneumonia Etiology Research for Child Health (PERCH) multicenter case-control study. We measured serum CRP levels in cases with World Health Organization-defined severe or very severe pneumonia and a subset of community controls. We evaluated the sensitivity and specificity of elevated CRP for "confirmed" bacterial pneumonia (positive blood culture or positive lung aspirate or pleural fluid culture or polymerase chain reaction [PCR]) compared to "RSV pneumonia" (nasopharyngeal/oropharyngeal or induced sputum PCR-positive without confirmed/suspected bacterial pneumonia). Receiver operating characteristic (ROC) curves were constructed to assess the performance of elevated CRP in distinguishing these cases. Among 601 human immunodeficiency virus (HIV)-negative tested controls, 3% had CRP ≥40 mg/L. Among 119 HIV-negative cases with confirmed bacterial pneumonia, 77% had CRP ≥40 mg/L compared with 17% of 556 RSV pneumonia cases. The ROC analysis produced an area under the curve of 0.87, indicating very good discrimination; a cut-point of 37.1 mg/L best discriminated confirmed bacterial pneumonia (sensitivity 77%) from RSV pneumonia (specificity 82%). CRP ≥100 mg/L substantially improved specificity over CRP ≥40 mg/L, though at a loss to sensitivity. Elevated CRP was positively associated with confirmed bacterial pneumonia and negatively associated with RSV pneumonia in PERCH. CRP may be useful for distinguishing bacterial from RSV-associated pneumonia, although its role in discriminating against other respiratory viral-associated pneumonia needs further study. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Association of C-Reactive Protein With Bacterial and Respiratory Syncytial Virus–Associated Pneumonia Among Children Aged <5 Years in the PERCH Study

PubMed Central

Le, Tham; O’Brien, Katherine L.; Murdoch, David R.; Prosperi, Christine; Baggett, Henry C.; Brooks, W. Abdullah; Feikin, Daniel R.; Hammitt, Laura L.; Howie, Stephen R. C.; Kotloff, Karen L.; Levine, Orin S.; Scott, J. Anthony G.; Thea, Donald M.; Awori, Juliet O.; Baillie, Vicky L.; Cascio, Stephanie; Chuananon, Somchai; DeLuca, Andrea N.; Driscoll, Amanda J.; Ebruke, Bernard E.; Endtz, Hubert P.; Kaewpan, Anek; Kahn, Geoff; Karani, Angela; Karron, Ruth A.; Moore, David P.; Park, Daniel E.; Rahman, Mohammed Ziaur; Salaudeen, Rasheed; Seidenberg, Phil; Somwe, Somwe Wa; Sylla, Mamadou; Tapia, Milagritos D.; Zeger, Scott L.; Deloria Knoll, Maria; Madhi, Shabir A.; O’Brien, Katherine L.; Levine, Orin S.; Knoll, Maria Deloria; Feikin, Daniel R.; DeLuca, Andrea N.; Driscoll, Amanda J.; Fancourt, Nicholas; Fu, Wei; Hammitt, Laura L.; Higdon, Melissa M.; Kagucia, E. Wangeci; Karron, Ruth A.; Li, Mengying; Park, Daniel E.; Prosperi, Christine; Wu, Zhenke; Zeger, Scott L.; Watson, Nora L.; Crawley, Jane; Murdoch, David R.; Brooks, W. Abdullah; Endtz, Hubert P.; Zaman, Khalequ; Goswami, Doli; Hossain, Lokman; Jahan, Yasmin; Ashraf, Hasan; Howie, Stephen R. C.; Ebruke, Bernard E.; Antonio, Martin; McLellan, Jessica; Machuka, Eunice; Shamsul, Arifin; Zaman, Syed M.A.; Mackenzie, Grant; Scott, J. Anthony G.; Awori, Juliet O.; Morpeth, Susan C.; Kamau, Alice; Kazungu, Sidi; Ominde, Micah Silaba; Kotloff, Karen L.; Tapia, Milagritos D.; Sow, Samba O.; Sylla, Mamadou; Tamboura, Boubou; Onwuchekwa, Uma; Kourouma, Nana; Toure, Aliou; Madhi, Shabir A.; Moore, David P.; Adrian, Peter V.; Baillie, Vicky L.; Kuwanda, Locadiah; Mudau, Azwifarwi; Groome, Michelle J.; Mahomed, Nasreen; Baggett, Henry C.; Thamthitiwat, Somsak; Maloney, Susan A.; Bunthi, Charatdao; Rhodes, Julia; Sawatwong, Pongpun; Akarasewi, Pasakorn; Thea, Donald M.; Mwananyanda, Lawrence; Chipeta, James; Seidenberg, Phil; Mwansa, James; Wa Somwe, Somwe; Kwenda, Geoffrey; Anderson, Trevor P.; Mitchell, Joanne

2017-01-01

Abstract Background. Lack of a gold standard for identifying bacterial and viral etiologies of pneumonia has limited evaluation of C-reactive protein (CRP) for identifying bacterial pneumonia. We evaluated the sensitivity and specificity of CRP for identifying bacterial vs respiratory syncytial virus (RSV) pneumonia in the Pneumonia Etiology Research for Child Health (PERCH) multicenter case-control study. Methods. We measured serum CRP levels in cases with World Health Organization–defined severe or very severe pneumonia and a subset of community controls. We evaluated the sensitivity and specificity of elevated CRP for “confirmed” bacterial pneumonia (positive blood culture or positive lung aspirate or pleural fluid culture or polymerase chain reaction [PCR]) compared to “RSV pneumonia” (nasopharyngeal/oropharyngeal or induced sputum PCR-positive without confirmed/suspected bacterial pneumonia). Receiver operating characteristic (ROC) curves were constructed to assess the performance of elevated CRP in distinguishing these cases. Results. Among 601 human immunodeficiency virus (HIV)–negative tested controls, 3% had CRP ≥40 mg/L. Among 119 HIV-negative cases with confirmed bacterial pneumonia, 77% had CRP ≥40 mg/L compared with 17% of 556 RSV pneumonia cases. The ROC analysis produced an area under the curve of 0.87, indicating very good discrimination; a cut-point of 37.1 mg/L best discriminated confirmed bacterial pneumonia (sensitivity 77%) from RSV pneumonia (specificity 82%). CRP ≥100 mg/L substantially improved specificity over CRP ≥40 mg/L, though at a loss to sensitivity. Conclusions. Elevated CRP was positively associated with confirmed bacterial pneumonia and negatively associated with RSV pneumonia in PERCH. CRP may be useful for distinguishing bacterial from RSV-associated pneumonia, although its role in discriminating against other respiratory viral-associated pneumonia needs further study. PMID:28575375

Ocean tides

NASA Technical Reports Server (NTRS)

Hendershott, M. C.

1975-01-01

A review of recent developments in the study of ocean tides and related phenomena is presented. Topics briefly discussed include: the mechanism by which tidal dissipation occurs; continental shelf, marginal sea, and baroclinic tides; estimation of the amount of energy stored in the tide; the distribution of energy over the ocean; the resonant frequencies and Q factors of oceanic normal modes; the relationship of earth tides and ocean tides; and numerical global tidal models.

Ancient DNA analysis of Indigenous rockfish use on the Pacific Coast: Implications for marine conservation areas and fisheries management

PubMed Central

McKechnie, Iain; Yang, Dongya Y.

2018-01-01

Rockfish (Sebastes spp.) are a common marine fish in nearshore and continental shelf environments in the North Pacific Ocean. They are frequently identified in coastal archaeological sites in western North America; however, the morphological similarity of rockfish species limits conventional zooarchaeological identifications to the genus level. This study applies ancient DNA analysis to 96 archaeological rockfish specimens from four sites on separate islands in an archipelago on western Vancouver Island, British Columbia, Canada. Two of the archaeological sites are located within a marine protected area specifically designed to facilitate the recovery of inshore rockfish populations; two sites are located outside this boundary and remain subject to considerable fishing pressure. Using mitochondrial 16S and control region DNA sequences, we identify at least twelve different rockfish species utilized during the past 2,500 years. Identification of rockfish at closely spaced and contemporaneously occupied sites confirms that a variety of Sebastes species were consistently exploited at each site, with more exposed areas having a higher number of species present. Identification results indicate that four of the twelve species did not occur within the conservation area boundary and, instead, were found in sites where commercial and recreational fishing continues to be permitted. This study demonstrates that ancient DNA identifications of archaeological assemblages can complement and expand perspective on modern day fisheries conservation and management in this National Park Reserve and First Nations ancestral territory. PMID:29438388

Functions of perch relocations in a communal night roost of wintering bald eagles

USGS Publications Warehouse

Yackel Adams, A.A.; Skagen, S.K.; Knight, R.L.

2000-01-01

We investigated the functions of perch relocations within a communal night roost of wintering bald eagles (Haliaeetus leucocephalus) along the Nooksack River, Washington, during two winters. We tested seven predictions of two nonexclusive hypotheses: (1) bald eagles relocate within roosts to assess foraging success of conspecifics and (2) bald eagles relocate to obtain thermoregulatory benefits from an improved microclimate. Additionally, we gathered descriptive information to allow refinement of further alternative hypotheses. We rejected the hypothesis that relocations are a means of assessing foraging success. Contrary to our expectations, immature eagles did not relocate to be closer to adults, and relocations were less frequent when food was less abundant. Our data support the hypothesis that eagles relocate within night roosts to obtain a favorable microclimate during winters when they are subjected to cold stress and food stress. In both winters, relocations were more frequent in the evening than in the morning. In both winters, most evening relocations were to the center of the roost rather than to its edge, and the frequency of relocation to the center was greater when temperatures were low. The microclimate hypothesis, however, explains only a limited number of relocations. Based on our findings, it is likely that relocation has multiple functions, including establishing and (or) maintaining foraging associations, establishing and (or) maintaining social-dominance hierarchies when food is less abundant, and nonsocial activities.

50 CFR Table 2d to Part 660... - At-Sea Whiting Fishery Annual Set-Asides, 2012 and beyond

Code of Federal Regulations, 2012 CFR

2012-10-01

... Annual Set-Asides, 2012 and beyond Species or species complex Set-aside (mt) Lingcod 6 Pacific Cod 5 Pacific Whiting Allocation a Sablefish N. of 36° 50 Sablefish S. of 36° NA PACIFIC OCEAN PERCH Allocation... Pacific Halibut 10 b a/ See Table 2.b., to Subpart C, for the at-sea whiting allocations for these species...

50 CFR Table 1d to Part 660... - At-Sea Whiting Fishery Annual Set-Asides, 2011

Code of Federal Regulations, 2012 CFR

2012-10-01

... Set-Asides, 2011 Species of species complex Set-aside (mt) Lingcod 6 Pacific Cod 5 Pacific Whiting Allocation a Sablefish N. of 36° 50 Sablefish S. of 36° NA PACIFIC OCEAN PERCH Allocation a WIDOW ROCKFISH... California scorpionfish NA Cabezon (off CA only) NA Other Fish 520 Longnose Skate 5 Pacific Halibut 10 b a...

Ocean color products from the Korean Geostationary Ocean Color Imager (GOCI).

PubMed

Wang, Menghua; Ahn, Jae-Hyun; Jiang, Lide; Shi, Wei; Son, SeungHyun; Park, Young-Je; Ryu, Joo-Hyung

2013-02-11

The first geostationary ocean color satellite sensor, Geostationary Ocean Color Imager (GOCI), which is onboard South Korean Communication, Ocean, and Meteorological Satellite (COMS), was successfully launched in June of 2010. GOCI has a local area coverage of the western Pacific region centered at around 36°N and 130°E and covers ~2500 × 2500 km(2). GOCI has eight spectral bands from 412 to 865 nm with an hourly measurement during daytime from 9:00 to 16:00 local time, i.e., eight images per day. In a collaboration between NOAA Center for Satellite Applications and Research (STAR) and Korea Institute of Ocean Science and Technology (KIOST), we have been working on deriving and improving GOCI ocean color products, e.g., normalized water-leaving radiance spectra (nLw(λ)), chlorophyll-a concentration, diffuse attenuation coefficient at the wavelength of 490 nm (Kd(490)), etc. The GOCI-covered ocean region includes one of the world's most turbid and optically complex waters. To improve the GOCI-derived nLw(λ) spectra, a new atmospheric correction algorithm was developed and implemented in the GOCI ocean color data processing. The new algorithm was developed specifically for GOCI-like ocean color data processing for this highly turbid western Pacific region. In this paper, we show GOCI ocean color results from our collaboration effort. From in situ validation analyses, ocean color products derived from the new GOCI ocean color data processing have been significantly improved. Generally, the new GOCI ocean color products have a comparable data quality as those from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the satellite Aqua. We show that GOCI-derived ocean color data can provide an effective tool to monitor ocean phenomenon in the region such as tide-induced re-suspension of sediments, diurnal variation of ocean optical and biogeochemical properties, and horizontal advection of river discharge. In particular, we show some examples of ocean

Connecting Ocean Heat Transport Changes from the Midlatitudes to the Arctic Ocean

NASA Astrophysics Data System (ADS)

Hezel, P.; Nummelin, A.; Li, C.

2017-12-01

Under greenhouse warming, climate models simulate a weakening of the Atlantic Meridional Overturning Circulation and the associated ocean heat transport at midlatitudes but an increase in the ocean heat transport to the Arctic Ocean. These opposing trends lead to what could appear to be a discrepancy in the reported ocean contribution to Arctic amplification. This study clarifies how ocean heat transport affects Arctic climate under strong greenhouse warming using a set of the 21st century simulations performed within the Coupled Model Intercomparison Project. The results suggest that a future reduction in subpolar ocean heat loss enhances ocean heat transport to the Arctic Ocean, driving an increase in Arctic Ocean heat content and contributing to the intermodel spread in Arctic amplification. The results caution against extrapolating the forced oceanic signal from the midlatitudes to the Arctic.

Change in diel catchability of young-of-year yellow perch associated with establishment of dreissenid mussels

USGS Publications Warehouse

Stapanian, Martin A.; Kocovsky, Patrick M.; Adams, Jean V.

2009-01-01

1. Non-native mussels have increased water clarity in many lakes and streams in North America and Europe. Diel variation in catchability of some fish species has been linked to visibility during survey trawls (used to measure escapement). 2. Water clarity increased in nearshore areas of western Lake Erie by the early 1990s, following passage of legislation in 1972 to improve water quality (e.g. reduce phosphorus loading) and the invasion of dreissenid mussels (Dreissena spp.) beginning in 1987. 3. We hypothesised that increased water clarity in Lake Erie resulted in decreased catchability of young-of-year (age-0) yellow perch (Perca flavescens Mitchill) during daylight compared to during night. We used a two-tiered modelling approach to test this hypothesis on the ratio (R) of catch per hour (CPH) during night to CPH during daylight in bottom trawl surveys conducted during 1961-2005. 4. First, we examined seven a priori models. The first model, the 'null' model, represented no change in R over time. Three more models tested whether the timing of the change in R was associated with passage of water quality legislation only, dreissenids only (two-period models) and both legislation and dreissenids (three-period models). Three additional models included a 3-year lag before the effects of legislation, dreissenids or both occurred. Secondly, all possible two- and three-period models with a minimum of 2 years per time period were explored a posteriori. The a posteriori procedure determined the temporal transitions to higher R that were best supported by the data, without regard to a priori hypotheses. 5. Night CPH was greater than daylight CPH in 3 of 11 years during 1961-72, in 10 of 15 years during 1973-87, and in 14 of 18 years during 1988-2005. During 1991-2005 night CPH exceeded daylight CPH in all years except one, and night CPH was more than twice daylight CPH in 10 years during this period. 6. The best a priori model had two periods, with a break between 1990 and

OCEAN-PC and a distributed network for ocean data

NASA Technical Reports Server (NTRS)

Mclain, Douglas R.

1992-01-01

The Intergovernmental Oceanographic Commission (IOC) wishes to develop an integrated software package for oceanographic data entry and access in developing countries. The software, called 'OCEAN-PC', would run on low cost PC microcomputers and would encourage and standardize: (1) entry of local ocean observations; (2) quality control of the local data; (3) merging local data with historical data; (4) improved display and analysis of the merged data; and (5) international data exchange. OCEAN-PC will link existing MS-DOS oceanographic programs and data sets with table-driven format conversions. Since many ocean data sets are now being distributed on optical discs (Compact Discs - Read Only Memory, CD-ROM, Mass et al. 1987), OCEAN-PC will emphasize access to CD-ROMs.

Harvesting the Ocean: 1. The Ocean.

ERIC Educational Resources Information Center

Caton, Albert, Ed.; And Others

This booklet is the first in a series of three interdisciplinary units which focus specifically on the Pacific Ocean and its surrounding countries. The booklet, designed for lower secondary students, provides an introduction to the ocean environment such that students can understand the physical factors underlying issues raised by the other two…

Ocean Prospects: A High School Teacher's Guide to Ocean-Related Topics.

ERIC Educational Resources Information Center

Plummer, C. M.

Provided in this guide are resources for these 11 topics: the physical/geological ocean; the chemical/biological ocean; the ocean's coasts; fishing and aquaculture; tourism, recreation, and development; mining and drilling; research and exploration; maritime and military; ocean technology; pollution; and resource management. These resources…

Role of oceanic air bubbles in atmospheric correction of ocean color imagery.

PubMed

Yan, Banghua; Chen, Bingquan; Stamnes, Knut

2002-04-20

Ocean color is the radiance that emanates from the ocean because of scattering by chlorophyll pigments and particles of organic and inorganic origin. Air bubbles in the ocean also scatter light and thus contribute to the water-leaving radiance. This additional water-leaving radiance that is due to oceanic air bubbles could violate the black pixel assumption at near-infrared wavelengths and be attributed to chlorophyll in the visible. Hence, the accuracy of the atmospheric correction required for the retrieval of ocean color from satellite measurements is impaired. A comprehensive radiative transfer code for the coupled atmosphere--ocean system is employed to assess the effect of oceanic air bubbles on atmospheric correction of ocean color imagery. This effect is found to depend on the wavelength-dependent optical properties of oceanic air bubbles as well as atmospheric aerosols.

Role of oceanic air bubbles in atmospheric correction of ocean color imagery

NASA Astrophysics Data System (ADS)

Yan, Banghua; Chen, Bingquan; Stamnes, Knut

2002-04-01

Ocean color is the radiance that emanates from the ocean because of scattering by chlorophyll pigments and particles of organic and inorganic origin. Air bubbles in the ocean also scatter light and thus contribute to the water-leaving radiance. This additional water-leaving radiance that is due to oceanic air bubbles could violate the black pixel assumption at near-infrared wavelengths and be attributed to chlorophyll in the visible. Hence, the accuracy of the atmospheric correction required for the retrieval of ocean color from satellite measurements is impaired. A comprehensive radiative transfer code for the coupled atmosphere-ocean system is employed to assess the effect of oceanic air bubbles on atmospheric correction of ocean color imagery. This effect is found to depend on the wavelength-dependent optical properties of oceanic air bubbles as well as atmospheric aerosols.

Should Controls With Respiratory Symptoms Be Excluded From Case-Control Studies of Pneumonia Etiology? Reflections From the PERCH Study.

PubMed

Higdon, Melissa M; Hammitt, Laura L; Deloria Knoll, Maria; Baggett, Henry C; Brooks, W Abdullah; Howie, Stephen R C; Kotloff, Karen L; Levine, Orin S; Madhi, Shabir A; Murdoch, David R; Scott, J Anthony G; Thea, Donald M; Driscoll, Amanda J; Karron, Ruth A; Park, Daniel E; Prosperi, Christine; Zeger, Scott L; O'Brien, Katherine L; Feikin, Daniel R

2017-06-15

Many pneumonia etiology case-control studies exclude controls with respiratory illness from enrollment or analyses. Herein we argue that selecting controls regardless of respiratory symptoms provides the least biased estimates of pneumonia etiology. We review 3 reasons investigators may choose to exclude controls with respiratory symptoms in light of epidemiologic principles of control selection and present data from the Pneumonia Etiology Research for Child Health (PERCH) study where relevant to assess their validity. We conclude that exclusion of controls with respiratory symptoms will result in biased estimates of etiology. Randomly selected community controls, with or without respiratory symptoms, as long as they do not meet the criteria for case-defining pneumonia, are most representative of the general population from which cases arose and the least subject to selection bias. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Ocean Opportunities. A Guide to What the Oceans Have to Offer.

ERIC Educational Resources Information Center

Burtis, William S.

High school students interested in ocean-related careers will find their imagination piqued by "Ocean Opportunities." As the ocean's resources are recognized more and more as extremely important economically, yet very fragile, study of those resources is burgeoning. This multi-color booklet describes the exciting opportunities which ocean research…

75 FR 56467 - Safety Zone; Ocean City Beachfront Air Show, Ocean City, NJ

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-16

...-AA00 Safety Zone; Ocean City Beachfront Air Show, Ocean City, NJ AGENCY: Coast Guard, DHS. ACTION... Atlantic Ocean, Ocean City, NJ. The temporary safety zone will restrict vessel traffic from a portion of the Atlantic Ocean during the Ocean City Beachfront Air Show, which is an aerial demonstration to be...

Proceedings of oceans 87. The ocean - an international workplace

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1987-01-01

This book includes proceedings containing 347 papers. Some of the topics are: ICE -Cold ocean and ice research; ICE-1-Icebergs; ICE-2-Sea ice and structures; IE-3-Cold ocean instrumentation; ICE-4-Ocean and ice; INS-Oceanographic instrumentation; INS-1-Acoustic Doppler Current profilers; ENG-1-New solutions to old problems; ENG-2-energy from the ocean; ENG-3-Cables and connectors; POL-Policy, education and technology transfer; POL-1-International issues; POL-2-Ocean space utilization; POL-3-Economics, planning and management; SCI-6-fish stock assessment; ACI-7-Coastal currents and sediment; SCI-9-Satellite navigation; SCI-10-Deep sea minerals and methods of recovery; ODS-Fifth working symposium on oceanographic data system; ODS-1-Data base management; UND-Underwater work systems; UND-1-Diving for science.

OceanSITES format and Ocean Observatory Output harmonisation: past, present and future

NASA Astrophysics Data System (ADS)

Pagnani, Maureen; Galbraith, Nan; Diggs, Stephen; Lankhorst, Matthias; Hidas, Marton; Lampitt, Richard

2015-04-01

The Global Ocean Observing System (GOOS) initiative was launched in 1991, and was the first step in creating a global view of ocean observations. In 1999 oceanographers at the OceanObs conference envisioned a 'global system of eulerian observatories' which evolved into the OceanSITES project. OceanSITES has been generously supported by individual oceanographic institutes and agencies across the globe, as well as by the WMO-IOC Joint Technical Commission for Oceanography and Marine Meteorology (under JCOMMOPS). The project is directed by the needs of research scientists, but has a strong data management component, with an international team developing content standards, metadata specifications, and NetCDF templates for many types of in situ oceanographic data. The OceanSITES NetCDF format specification is intended as a robust data exchange and archive format specifically for time-series observatory data from the deep ocean. First released in February 2006, it has evolved to build on and extend internationally recognised standards such as the Climate and Forecast (CF) standard, BODC vocabularies, ISO formats and vocabularies, and in version 1.3, released in 2014, ACDD (Attribute Convention for Dataset Discovery). The success of the OceanSITES format has inspired other observational groups, such as autonomous vehicles and ships of opportunity, to also use the format and today it is fulfilling the original concept of providing a coherent set of data from eurerian observatories. Data in the OceanSITES format is served by 2 Global Data Assembly Centres (GDACs), one at Coriolis, in France, at ftp://ftp.ifremer.fr/ifremer/oceansites/ and one at the US NDBC, at ftp://data.ndbc.noaa.gov/data/oceansites/. These two centres serve over 26,800 OceanSITES format data files from 93 moorings. The use of standardised and controlled features enables the files held at the OceanSITES GDACs to be electronically discoverable and ensures the widest access to the data. The Ocean

Southern Ocean vertical iron fluxes; the ocean model effect

NASA Astrophysics Data System (ADS)

Schourup-Kristensen, V.; Haucke, J.; Losch, M. J.; Wolf-Gladrow, D.; Voelker, C. D.

2016-02-01

The Southern Ocean plays a key role in the climate system, but commonly used large-scale ocean general circulation biogeochemical models give different estimates of current and future Southern Ocean net primary and export production. The representation of the Southern Ocean iron sources plays an important role for the modeled biogeochemistry. Studies of the iron supply to the surface mixed layer have traditionally focused on the aeolian and sediment contributions, but recent work has highlighted the importance of the vertical supply from below. We have performed a model study in which the biogeochemical model REcoM2 was coupled to two different ocean models, the Finite Element Sea-ice Ocean Model (FESOM) and the MIT general circulation model (MITgcm) and analyzed the magnitude of the iron sources to the surface mixed layer from below in the two models. Our results revealed a remarkable difference in terms of mechanism and magnitude of transport. The mean iron supply from below in the Southern Ocean was on average four times higher in MITgcm than in FESOM and the dominant pathway was entrainment in MITgcm, whereas diffusion dominated in FESOM. Differences in the depth and seasonal amplitude of the mixed layer between the models affect on the vertical iron profile, the relative position of the base of the mixed layer and ferricline and thereby also on the iron fluxes. These differences contribute to differences in the phytoplankton composition in the two models, as well as in the timing of the onset of the spring bloom. The study shows that the choice of ocean model has a significant impact on the iron supply to the Southern Ocean mixed layer and thus on the modeled carbon cycle, with possible implications for model runs predicting the future carbon uptake in the region.

The Ocean Literacy Campaign

NASA Astrophysics Data System (ADS)

Schoedinger, S. E.; Strang, C.

2008-12-01

"Ocean Literacy is an understanding of the ocean's influence on you and your influence on the ocean." This simple statement captures the spirit of a conceptual framework supporting ocean literacy (COSEE et al., 2005). The framework comprises 7 essential principles and 44 fundamental concepts an ocean literate person would know (COSEE et al., 2005). The framework is the result of an extensive grassroots effort to reach consensus on (1) a definition for ocean literacy and (2) an articulation of the most important concepts to be understood by ocean-literate citizen (Cava et al., 2005). In the process of reaching consensus on these "big ideas" about the ocean, what began as a series of workshops has emerged as a campaign "owned" by an ever-expanding community of individuals, organizations and networks involved in developing and promoting the framework. The Ocean Literacy Framework has provided a common language for scientists and educators working together and serves as key guidance for the ocean science education efforts. This presentation will focus on the impact this Ocean Literacy Campaign has had to date as well as efforts underway to provide additional tools to enable educators and educational policy makers to further integrate teaching and learning about the ocean and our coasts into formal K-12 education and informal education. COSEE, National Geographic Society, NOAA, College of Exploration (2005). Ocean Literacy: The Essential Principles of Ocean Sciences Grades K-12, a jointly published brochure, URL: http://www.coexploration.org/oceanliteracy/documents/OceanLitChart.pdf Cava, F., S. Schoedinger , C. Strang, and P. Tuddenham (2005). Science Content and Standards for Ocean Literacy: A Report on Ocean Literacy, URL: http://www.coexploration.org/oceanliteracy/documents/OLit2004-05_Final_Report.pdf.

Blue ocean strategy.

PubMed

Kim, W Chan; Mauborgne, Renée

2004-10-01

Despite a long-term decline in the circus industry, Cirque du Soleil profitably increased revenue 22-fold over the last ten years by reinventing the circus. Rather than competing within the confines of the existing industry or trying to steal customers from rivals, Cirque developed uncontested market space that made the competition irrelevant. Cirque created what the authors call a blue ocean, a previously unknown market space. In blue oceans, demand is created rather than fought over. There is ample opportunity for growth that is both profitable and rapid. In red oceans--that is, in all the industries already existing--companies compete by grabbing for a greater share of limited demand. As the market space gets more crowded, prospects for profits and growth decline. Products turn into commodities, and increasing competition turns the water bloody. There are two ways to create blue oceans. One is to launch completely new industries, as eBay did with online auctions. But it's much more common for a blue ocean to be created from within a red ocean when a company expands the boundaries of an existing industry. In studying more than 150 blue ocean creations in over 30 industries, the authors observed that the traditional units of strategic analysis--company and industry--are of limited use in explaining how and why blue oceans are created. The most appropriate unit of analysis is the strategic move, the set of managerial actions and decisions involved in making a major market-creating business offering. Creating blue oceans builds brands. So powerful is blue ocean strategy, in fact, that a blue ocean strategic move can create brand equity that lasts for decades.

Slowing Ocean Acidification

NASA Astrophysics Data System (ADS)

Bravo, A.

2016-12-01

Currently our ocean's pH is 8.1, a decrease from 8.2 in the past 200 years since the beginning of the industrial revolution. The ocean absorbs about a third of the carbon dioxide (CO2) from the atmosphere, which is helpful to us, since reducing the amount of CO2 in the atmosphere shows global warming. However, what is the impact of all that CO2 on the ocean? I evaluated the effect of acidic water on bivalves, and found that the shells were broken down with exposure to increased acidity. I am concerned that continued ocean acidification will impact organisms that are unable to adapt to the changing ocean chemistry. While the US currently invests in alternative forms of energy including solar and wind, approximately 66% of our energy comes from sources that are releasing CO2 into the atmosphere. I want to explore the potential of wave energy as another form of renewable energy. When wind blows over the surface of the ocean, it creates a wave. Could this wave energy be a consistent clean energy source? Could a strategy to slow and reverse ocean acidification be found in the ocean?

Influence of basin- and local-scale environmental conditions on nearshore production in the northeast Pacific Ocean

USGS Publications Warehouse

von Biela, Vanessa R.; Zimmerman, Christian E.; Kruse, Gordon H.; Mueter, Franz J.; Black, Bryan A.; Douglas, David C.; Bodkin, James L.

2016-01-01

Nearshore marine habitats are productive and vulnerable owing to their connections to pelagic and terrestrial landscapes. To understand how ocean basin- and local-scale conditions may influence nearshore species, we developed an annual index of nearshore production (spanning the period 1972–2010) from growth increments recorded in otoliths of representative pelagic-feeding (Black Rockfish Sebastes melanops) and benthic-feeding (Kelp Greenling Hexagrammos decagrammus) nearshore-resident fishes at nine sites in the California Current and Alaska Coastal Current systems. We explored the influence of basin- and local-scale conditions across all seasons at lags of up to 2 years to represent changes in prey quantity (1- or 2-year time lags) and quality (within-year relationships). Relationships linking fish growth to basin-scale (Pacific Decadal Oscillation, North Pacific Gyre Oscillation, and multivariate El Niño–Southern Oscillation index) and local-scale (sea surface temperature, sea surface height anomalies, upwelling index, photosynthetically active radiation, and freshwater discharge) environmental conditions varied by species and current system. Growth of Black Rockfish increased with cool basin-scale conditions in the California Current and warm local-scale conditions in the Alaska Coastal Current, consistent with existing hypotheses linking climate to pelagic production on continental shelves in the respective regions. Relationships for Kelp Greenlings in the California Current were complex, with faster growth related to within-year warm conditions and lagged-year cool conditions. These opposing, lag-dependent relationships may reflect differences in conditions that promote quantity versus quality of benthic invertebrate prey in the California Current. Thus, we hypothesize that benthic production is maximized by alternating cool and warm years, as benthic invertebrate recruitment is food limited during warm years while growth is temperature limited by cool

Taking the ocean pledge

NASA Astrophysics Data System (ADS)

Showstack, Randy

The National Oceanic and Atmospheric Administration (NOAA) is sponsoring an "ocean ambassadors pledge campaign" to encourage students and others to make a personal, long-term commitment to caring for the world's oceans.The pledge campaign, which is part of NOAA's public awareness efforts for the International Year of the Ocean, calls for people to learn what they can about oceans, be considerate to ocean wildlife, conserve water, and implement other simple measures.

Ocean Tracks: Investigating Marine Migrations in a Changing Ocean

NASA Astrophysics Data System (ADS)

Krumhansl, R.; Kochevar, R. E.; Aluwihare, L.; Bardar, E. W.; Hirsch, L.; Hoyle, C.; Krumhansl, K.; Louie, J.; Madura, J.; Mueller-Northcott, J.; Peach, C. L.; Trujillo, A.; Winney, B.; Zetterlind, V.; Busey, A.

2015-12-01

The availability of scientific data sets online opens up exciting new opportunities to raise students' understanding of the worlds' oceans and the potential impacts of climate change. The Oceans of Data Institute at EDC; Stanford University; and the Scripps Institution of Oceanography have been collaborating, with the support of three National Science Foundation grants over the past 5 years, to bring marine science data sets into high school and undergraduate classrooms. These efforts have culminated in the development of a web-based student interface to data from the Tagging of Pacific Predators (TOPP) program, NOAA's Global Drifter Program, and NASA Earth-orbiting satellites through a student-friendly Web interface, customized data analysis tools, multimedia supports, and course modules. Ocean Tracks (http://oceantracks.org), which incorporates design principles based on a broad range of research findings in fields such as cognitive science, visual design, mathematics education and learning science, focuses on optimizing students' opportunities to focus their cognitive resources on viewing and comparing data to test hypotheses, while minimizing the time spent on downloading, filtering and creating displays. Ocean Tracks allows students to display the tracks of elephant seals, white sharks, Bluefin tuna, albatross, and drifting buoys along with sea surface temperature, chlorophyll-A, bathymetry, ocean currents, and human impacts overlays. A graphing tool allows students to dynamically display parameters associated with the track such as speed, deepest daily dive and track tortuosity (curviness). These interface features allow students to engage in investigations that mirror those currently being conducted by scientists to understand the broad-scale effects of changes in climate and other human activities on ocean ecosystems. In addition to supporting the teaching of the Ocean and Climate Literacy principles, high school curriculum modules facilitate the teaching

Global Ocean Vertical Velocity From a Dynamically Consistent Ocean State Estimate

NASA Astrophysics Data System (ADS)

Liang, Xinfeng; Spall, Michael; Wunsch, Carl

2017-10-01

Estimates of the global ocean vertical velocities (Eulerian, eddy-induced, and residual) from a dynamically consistent and data-constrained ocean state estimate are presented and analyzed. Conventional patterns of vertical velocity, Ekman pumping, appear in the upper ocean, with topographic dominance at depth. Intense and vertically coherent upwelling and downwelling occur in the Southern Ocean, which are likely due to the interaction of the Antarctic Circumpolar Current and large-scale topographic features and are generally canceled out in the conventional zonally averaged results. These "elevators" at high latitudes connect the upper to the deep and abyssal oceans and working together with isopycnal mixing are likely a mechanism, in addition to the formation of deep and abyssal waters, for fast responses of the deep and abyssal oceans to the changing climate. Also, Eulerian and parameterized eddy-induced components are of opposite signs in numerous regions around the global ocean, particularly in the ocean interior away from surface and bottom. Nevertheless, residual vertical velocity is primarily determined by the Eulerian component, and related to winds and large-scale topographic features. The current estimates of vertical velocities can serve as a useful reference for investigating the vertical exchange of ocean properties and tracers, and its complex spatial structure ultimately permits regional tests of basic oceanographic concepts such as Sverdrup balance and coastal upwelling/downwelling.

Oceans & Coasts | National Oceanic and Atmospheric Administration

Science.gov Websites

NOAA's National Ocean Service is positioning America's coastal communities for the future Focus_Area_oceanscoasts1.jpg NOAA NOAA's National Ocean Service is positioning America's coastal communities for the future them. Almost 40 percent of the country's population lives in coastal shoreline counties. These counties

Effect of high pressure processing on textural and microbiological quality of pink perch (Nemipterus japonicus) sausage during chilled storage

NASA Astrophysics Data System (ADS)

Kunnath, Sarika; Panda, Satyen Kumar; Jaganath, Bindu; Gudipati, Venkateshwarlu

2015-10-01

The non-thermal high pressure (HP) processing was studied on fish sausage to enhance the quality during chilled storage. Pink perch (Nemipterus japonicus) sausages, packed in poly amide casing under vacuum were subjected to 400, 500 and 600 MPa pressures (dwell time: 10 min and ramp rate: 300 MPa/min) and compared with heat-set samples for physico-chemical and microbial quality parameters. Pressurized samples formed softer and glossier gels with a slight reduction in water-holding capacity. HP made the texture of sausage softer, cohesive and less chewy and gummier than heat-treated ones. Folding test seen higher acceptance values in samples treated at 500 and 600 MPa, during storage. Maximum log reduction in microbial count was observed in 600 MPa immediately, and significant difference in cooked and pressurized sausages was seen only up to 7th day. This revealed the potential application of HP in replacing conventional heat treatment for sausages preparation with enhanced shelf-life.

Emerging ocean issues

NASA Astrophysics Data System (ADS)

Richman, Barbara T.

1984-04-01

Seven topics have been identified by the topics committee of the Year of the Ocean as focal points of discussions as part of the Year of the Ocean celebration. The Year of the Ocean (Eos, June 19, 1984, p. 402, and April 24, 1984, p. 326) is a year-long commemoration and celebration, begun on July 1, of the oceans. The commemoration has been endorsed by Congress and by President Ronald Reagan.The topics committee is composed of nearly 20 representatives from government, industry, and academia. Thomas Maginnis, director of the National Oceanic and Atmospheric Administration's office of policy and planning, is the chairman of the topics committee.

Ichthyophonus in sport-caught groundfishes from southcentral Alaska

USGS Publications Warehouse

Harris, Bradley P.; Webster, Sarah R.; Wolf, Nathan; Gregg, Jacob L.; Hershberger, Paul

2018-01-01

This report of Ichthyophonus in common sport-caught fishes throughout the marine waters of southcentral Alaska represents the first documentation of natural Ichthyophonus infections in lingcod Ophiodon elongates and yelloweye rockfish Sebastes ruberrimus. In addition, the known geographic range of Ichthyophonus in black rockfish S. melanops has been expanded northward to include southcentral Alaska. Among all species surveyed, the infection prevalence was highest (35%, n = 334) in Pacific halibut Hippoglossus stenolepis. There were no gross indications of high-level infections or clinically diseased individuals. These results support the hypothesis that under typical conditions Ichthyophonus can occur at high infection prevalence accompanied with low-level infection among a variety of fishes throughout the eastern North Pacific Ocean, including southcentral Alaska.

Anisakid nematodes in beaked redfish (Sebastes mentella) from three fishing grounds in the North Atlantic, with special notes on distribution in the fish musculature.

PubMed

Klapper, Regina; Kuhn, Thomas; Münster, Julian; Levsen, Arne; Karl, Horst; Klimpel, Sven

2015-01-15

Parasitic anisakid nematodes commonly occur in the musculature and visceral organs of many fish species from the North Atlantic. In this respect, the presence of the third stage larvae of Anisakis spp. in the fish musculature may pose a potential consumer hazard due to the parasite's ability to cause anisakidosis. Thus, knowledge on the occurrence and distribution of these potentially zoonotic parasites in the commercially important North Atlantic fish species is crucial in order to evaluate and consequently prevent human infections. In the present study, 300 Sebastes mentella from three North Atlantic fishing grounds (Northern North Sea: Tampen; Barents Sea: off Bear Island; Irminger Sea: off SE Greenland) were examined for anisakid nematodes, with emphasis on occurrence and distribution in the musculature. Overall larval prevalence and mean intensity were significantly higher in redfish from Tampen (94%; 13.5±20.0) and Bear Island (94%; 14.5±19.4) than in fish from SE Greenland (75%; 6.0±5.8; p<0.01). The same trend was observed for larval infection in the musculature showing prevalence and mean intensities of 79%, 73%, and 55%, and 5.9±6.6, 5.8±6.5, and 3.2±2.4, in the musculature of redfish from Tampen, Bear Island, and Greenland, respectively. Conventional microscopy and rDNA ITS-gene sequencing of various subsamples of muscle-dwelling nematode larvae of redfish from every catching locality revealed the presence of two anisakid species; Anisakis simplex sensu stricto and the non-zoonotic Hysterothylacium aduncum. Since the larvae of H. aduncum typically occur in or on the viscera of fish, our findings of two specimens in the belly flaps of redfish were unusual. Additionally, more than 92% of the muscle-dwelling larvae occurred in the belly flaps, i.e. the hypaxial part of the musculature surrounding the visceral organs on either fish side. Thus, trimming the fillets of beaked redfish by removal of most of the belly flaps would significantly reduce the

An inventory of Arctic Ocean data in the World Ocean Database

NASA Astrophysics Data System (ADS)

Zweng, Melissa M.; Boyer, Tim P.; Baranova, Olga K.; Reagan, James R.; Seidov, Dan; Smolyar, Igor V.

2018-03-01

The World Ocean Database (WOD) contains over 1.3 million oceanographic casts (where cast refers to an oceanographic profile or set of profiles collected concurrently at more than one depth between the ocean surface and ocean bottom) collected in the Arctic Ocean basin and its surrounding marginal seas. The data, collected from 1849 to the present, come from many submitters and countries, and were collected using a variety of instruments and platforms. These data, along with the derived products World Ocean Atlas (WOA) and the Arctic Regional Climatologies, are exceptionally useful - the data are presented in a standardized, easy to use format and include metadata and quality control information. Collecting data in the Arctic Ocean is challenging, and coverage in space and time ranges from excellent to nearly non-existent. WOD continues to compile a comprehensive collection of Arctic Ocean profile data, ideal for oceanographic, environmental and climatic analyses (https://doi.org/10.7289/V54Q7S16).

The tongue of the ocean as a remote sensing ocean color calibration range

NASA Technical Reports Server (NTRS)

Strees, L. V.

1972-01-01

In general, terrestrial scenes remain stable in content from both temporal and spacial considerations. Ocean scenes, on the other hand, are constantly changing in content and position. The solar energy that enters the ocean waters undergoes a process of scattering and selective spectral absorption. Ocean scenes are thus characterized as low level radiance with the major portion of the energy in the blue region of the spectrum. Terrestrial scenes are typically of high level radiance with their spectral energies concentrated in the green-red regions of the visible spectrum. It appears that for the evaluation and calibration of ocean color remote sensing instrumentation, an ocean area whose optical ocean and atmospheric properties are known and remain seasonably stable over extended time periods is needed. The Tongue of the Ocean, a major submarine channel in the Bahama Banks, is one ocean are for which a large data base of oceanographic information and a limited amount of ocean optical data are available.

Oceanic dispersion of Fukushima-derived Cs-137 in the coastal, offshore, and open oceans simulated by multiple oceanic general circulation models

NASA Astrophysics Data System (ADS)

Kawamura, H.; Furuno, A.; Kobayashi, T.; In, T.; Nakayama, T.; Ishikawa, Y.; Miyazawa, Y.; Usui, N.

2017-12-01

To understand the concentration and amount of Fukushima-derived Cs-137 in the ocean, this study simulates the oceanic dispersion of Cs-137 by an oceanic dispersion model SEA-GEARN-FDM developed at Japan Atomic Energy Agency (JAEA) and multiple oceanic general circulation models. The Cs-137 deposition amounts at the sea surface were used as the source term in oceanic dispersion simulations, which were estimated by atmospheric dispersion simulations with a Worldwide version of System for Prediction of Environmental Emergency Dose Information version II (WSPEEDI-II) developed at JAEA. The direct release from the Fukushima Daiichi Nuclear Power Plant into the ocean based on in situ Cs-137 measurements was used as the other source term in oceanic dispersion simulations. The simulated air Cs-137 concentrations qualitatively replicated those measured around the North Pacific. The accumulated Cs-137 ground deposition amount in the eastern Japanese Islands was consistent with that estimated by aircraft measurements. The oceanic dispersion simulations relatively well reproduced the measured Cs-137 concentrations in the coastal and offshore oceans during the first few months after the Fukushima disaster, and in the open ocean during the first year post-disaster. It was suggested that Cs-137 dispersed along the coast in the north-south direction during the first few months post-disaster, and were subsequently dispersed offshore by the Kuroshio Current and Kuroshio Extension. Mesoscale eddies accompanied by the Kuroshio Current and Kuroshio Extension played an important role in dilution of Cs-137. The Cs-137 amounts were quantified in the coastal, offshore, and open oceans during the first year post-disaster. It was demonstrated that Cs-137 actively dispersed from the coastal and offshore oceans to the open ocean, and from the surface layer to the deeper layer in the North Pacific.

A study on atmospheric and oceanic processes in the north Indian Ocean

NASA Astrophysics Data System (ADS)

Felton, Clifford S.

Studies on oceanic and atmospheric processes in the Indian Ocean are an active and important area of scientific research. Understanding how intraseasonal and interannual variations impact both the ocean and atmosphere will aid in delineating potential feedback mechanisms and global teleconnections. Thanks to recent efforts focused on expanding observational capabilities and developing models for this region, researchers have been able to begin investigating atmospheric and oceanic processes in the Indian Ocean. This study focuses on the impact of the El Nino Southern Oscillation (ENSO) on tropical cyclone activity over the Bay of Bengal (BoB) and on developing a method for estimating the barrier layer thickness (BLT) in the Indian Ocean from satellite observations. National Center for Environmental Prediction (NCEP-2) and Simple Ocean Data Assimilation (SODA) reanalysis data are used to investigate the alterations in atmospheric and oceanic conditions that impact tropical cyclones during ENSO events over a 33-year time frame (1979-2011). Atmospheric conditions are shown to be more favorable for tropical cyclone development during La Nina over the BoB due to the favorable alteration of large-scale wind, moisture, and vorticity distributions. By combining multiple satellite observations, including the recently launched Soil Moisture and Ocean Salinity (SMOS) and Aquarius SAC-D salinity missions, BLT estimates for the Indian Ocean are generated with the use of a multilinear regression model (MRM). The performance of the MRM is evaluated for the Southeast Arabian Sea (SEAS), Bay of Bengal (BoB), and Eastern Equatorial Indian Ocean (EEIO) where barrier layer formation is most rigorous. Results from the MRM suggest that salinity measurements obtained from Aquarius and SMOS can be useful for tracking and predicting the BLT in the Indian Ocean.

Ocean acoustic reverberation tomography.

PubMed

Dunn, Robert A

2015-12-01

Seismic wide-angle imaging using ship-towed acoustic sources and networks of ocean bottom seismographs is a common technique for exploring earth structure beneath the oceans. In these studies, the recorded data are dominated by acoustic waves propagating as reverberations in the water column. For surveys with a small receiver spacing (e.g., <10 km), the acoustic wave field densely samples properties of the water column over the width of the receiver array. A method, referred to as ocean acoustic reverberation tomography, is developed that uses the travel times of direct and reflected waves to image ocean acoustic structure. Reverberation tomography offers an alternative approach for determining the structure of the oceans and advancing the understanding of ocean heat content and mixing processes. The technique has the potential for revealing small-scale ocean thermal structure over the entire vertical height of the water column and along long survey profiles or across three-dimensional volumes of the ocean. For realistic experimental geometries and data noise levels, the method can produce images of ocean sound speed on a smaller scale than traditional acoustic tomography.

77 FR 41332 - Fisheries of the Exclusive Economic Zone Off Alaska; Arrowtooth Flounder, Flathead Sole, Rex Sole...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-13

...NMFS is prohibiting directed fishing for arrowtooth flounder, flathead sole, rex sole, deep-water flatfish, and shallow-water flatfish in the Western Regulatory Area of the Gulf of Alaska (GOA). This action is necessary to limit incidental catch of Pacific ocean perch by vessels fishing for arrowtooth flounder, flathead sole, rex sole, deep-water flatfish, and shallow-water flatfish in the Western Regulatory Area of the GOA.

The Physical Ocean.

ERIC Educational Resources Information Center

NatureScope, 1988

1988-01-01

Examines the physical properties of the ocean (including the composition of seawater; waves, currents, and tides) and the topography of the ocean floor. Included are (1) activities on oceans, saltwater, and the sea floor; and (2) questions, and a puzzle which can be copied. (Author/RT)

Ethane ocean on Titan

NASA Technical Reports Server (NTRS)

Lunine, J. I.; Stevenson, D. J.; Yung, Y.L.

1983-01-01

Voyager I radio occultation data is employed to develop a qualitative model of an ethane ocean on Titan. It is suggested that the ocean contains 25 percent CH4 and that the ocean is in dynamic equilibrium with an N2 atmosphere. Previous models of a CH4 ocean are discounted due to photolysis rates of CH4 gas. Tidal damping of Titan's orbital eccentricity is taken as evidence for an ocean layer approximately 1 km deep, with the ocean floor being covered with a solid C2H2 layer 100 to 200 m thick. The photolytic process disrupting the CH4, if the estimates of the oceanic content of CH4 are correct, could continue for at least one billion years. Verification of the model is dependent on detecting CH4 clouds in the lower atmosphere, finding C2H6 saturation in the lower troposphere, or obtaining evidence of a global ocean.

Fifty-fifth Christmas Bird Count. 159. Ocean City, Md

USGS Publications Warehouse

Robbins, C.S.

1955-01-01

The distribution of dynamic pressure behind a Harris' hawk's wing was sampled using a wake rake consisting of 15 pitot tubes and one static tube. The hawk was holding on to a perch, but at an air speed and gliding angle at which it was capable of gliding. The perch was instrumented, so that the lift developed by the wing was known and the lift coefficient could be calculated. The mean of 92 estimates of profile drag coefficient was 0.0207, with standard deviation 0.0079. Lift coefficients ranged from 0.51 to 1.08. Reynolds numbers were nearly all in the range 143000-194000. The estimates of profile drag coefficient were reconcilable with previous estimates of the wing profile drag of the same bird, obtained by the subtractive method, and also with values predicted by the ?Airfoil-ii? program for designing aerofoils, based on a digitized wing profile from the ulnar region of the wing. The thickness of the wake suggested that the boundary layer was mostly or fully turbulent in most observations and separated in some, possibly as an active means of creating drag for control purposes. It appears that the bird could momentarily either increase or decrease the profile drag of specific parts of the wing, by active changes of shape, and it appeared to use the carpo-metacarpal region especially for such control movements. Further investigation in a low turbulence wind tunnel would help to resolve doubts about the possible influence of airstream turbulence on the behaviour of the boundary layer.

Fifty-fifth Christmas Bird Count. 159. Ocean City, Md

USGS Publications Warehouse

Pennycuick, C.J.; Heine, C.E.; Kirkpatrick, S.J.; Fuller, M.R.

1992-01-01

The distribution of dynamic pressure behind a Harris' hawk's wing was sampled using a wake rake consisting of 15 pitot tubes and one static tube. The hawk was holding on to a perch, but at an air speed and gliding angle at which it was capable of gliding. The perch was instrumented, so that the lift developed by the wing was known and the lift coefficient could be calculated. The mean of 92 estimates of profile drag coefficient was 0.0207, with standard deviation 0.0079. Lift coefficients ranged from 0.51 to 1.08. Reynolds numbers were nearly all in the range 143000-194000. The estimates of profile drag coefficient were reconcilable with previous estimates of the wing profile drag of the same bird, obtained by the subtractive method, and also with values predicted by the `Airfoil-ii? program for designing aerofoils, based on a digitized wing profile from the ulnar region of the wing. The thickness of the wake suggested that the boundary layer was mostly or fully turbulent in most observations and separated in some, possibly as an active means of creating drag for control purposes. It appears that the bird could momentarily either increase or decrease the profile drag of specific parts of the wing, by active changes of shape, and it appeared to use the carpo-metacarpal region especially for such control movements. Further investigation in a low turbulence wind tunnel would help to resolve doubts about the possible influence of airstream turbulence on the behaviour of the boundary layer.

Global Ocean Phytoplankton

NASA Technical Reports Server (NTRS)

Franz, B. A.; Behrenfeld, M. J.; Siegel, D. A.; Werdell, P. J.

2014-01-01

Marine phytoplankton are responsible for roughly half the net primary production (NPP) on Earth, fixing atmospheric CO2 into food that fuels global ocean ecosystems and drives the ocean's biogeochemical cycles. Phytoplankton growth is highly sensitive to variations in ocean physical properties, such as upper ocean stratification and light availability within this mixed layer. Satellite ocean color sensors, such as the Sea-viewing Wide Field-of-view Sensor (SeaWiFS; McClain 2009) and Moderate Resolution Imaging Spectroradiometer (MODIS; Esaias 1998), provide observations of sufficient frequency and geographic coverage to globally monitor physically-driven changes in phytoplankton distributions. In practice, ocean color sensors retrieve the spectral distribution of visible solar radiation reflected upward from beneath the ocean surface, which can then be related to changes in the photosynthetic phytoplankton pigment, chlorophyll- a (Chla; measured in mg m-3). Here, global Chla data for 2013 are evaluated within the context of the 16-year continuous record provided through the combined observations of SeaWiFS (1997-2010) and MODIS on Aqua (MODISA; 2002-present). Ocean color measurements from the recently launched Visible and Infrared Imaging Radiometer Suite (VIIRS; 2011-present) are also considered, but results suggest that the temporal calibration of the VIIRS sensor is not yet sufficiently stable for quantitative global change studies. All MODISA (version 2013.1), SeaWiFS (version 2010.0), and VIIRS (version 2013.1) data presented here were produced by NASA using consistent Chla algorithms.

Organophosphorus esters in the oceans and possible relation with ocean gyres.

PubMed

Cheng, Wenhan; Xie, Zhouqing; Blais, Jules M; Zhang, Pengfei; Li, Ming; Yang, Chengyun; Huang, Wen; Ding, Rui; Sun, Liguang

2013-09-01

Four organophosphorus esters (OPEs) were detected in aerosol samples collected in the West Pacific, the Indian Ocean and the Southern Ocean from 2009 to 2010, suggesting their circumpolar and global distribution. In general, the highest concentrations were detected near populated regions in China, Australia and New Zealand. OPE concentrations in the Southern Ocean were about two orders of magnitude lower than those near major continents. Additionally, relatively high OPE concentrations were detected at the Antarctic Peninsula, where several scientific survey stations are located. The four OPEs investigated here are significantly correlated with each other, suggesting they may derive from the same source. In the circumpolar transect, OPE concentrations were associated with ocean gyres in the open ocean. Their concentrations were positively related with average vorticity in the sampling area suggesting that a major source of OPEs may be found in ocean gyres where plastic debris is known to accumulate. Copyright © 2013 Elsevier Ltd. All rights reserved.

Larval dispersal underlies demographically important inter-system connectivity in a Great Lakes yellow perch (Perca flavescens) population

USGS Publications Warehouse

Brodnik, Reed M.; Fraker, Michael E.; Anderson, Eric J.; Carreon-Martinez, Lucia; DeVanna, Kristen M.; Heath, Dan D.; Reichert, Julie M.; Roseman, Edward F.; Ludsin, Stuart A.

2016-01-01

Ability to quantify connectivity among spawning subpopulations and their relative contribution of recruits to the broader population is a critical fisheries management need. By combining microsatellite and age information from larval yellow perch (Perca flavescens) collected in the Lake St. Clair – Detroit River system (SC-DRS) and western Lake Erie with a hydrodynamic backtracking approach, we quantified subpopulation structure, connectivity, and contributions of recruits to the juvenile stage in western Lake Erie during 2006-2007. After finding weak (yet stable) genetic structure between the SC-DRS and two western Lake Erie subpopulations, microsatellites also revealed measurable recruitment of SC-DRS larvae to the juvenile stage in western Lake Erie (17-21% during 2006-2007). Consideration of pre-collection larval dispersal trajectories, using hydrodynamic backtracking, increased estimated contributions to 65% in 2006 and 57% in 2007. Our findings highlight the value of complementing subpopulation discrimination methods with hydrodynamic predictions of larval dispersal by revealing the SC-DRS as a source of recruits to western Lake Erie and also showing that connectivity through larval dispersal can affect the structure and dynamics of large-lake fish populations.

Effects of freezing on white perch Morone americana (Gmelin, 1789): Implications for multivariate morphometrics

USGS Publications Warehouse

Kocovsky, Patrick

2016-01-01

This study tested the hypothesis that duration of freezing differentially affects whole-body morphometrics of a derived teleost. Whole-body morphometrics are frequently analyzed to test hypotheses of different species, or stocks within a species, of fishes. Specimens used for morphometric analyses are typically fixed or preserved prior to analysis, yet little research has been done on how fixation or preservation methods or duration of preservation of specimens might affect outcomes of multivariate statistical analyses of differences in shape. To determine whether whole-body morphometrics changed as a result of freezing, 23 whole-body morphometrics of age-1 white perch (Morone americana) from western Lake Erie (n = 211) were analyzed immediately after capture, after being held on ice overnight, and after freezing for 100 or 200 days. Discriminant function analysis revealed that all four groups differed significantly from one another (P < 0.0001). The first canonical axis reflected long-axis morphometrics, where there was a clear pattern of positive translation along this axis with duration of preservation. Re-classification analysis demonstrated fish were typically assigned to their original preservation class except for fish frozen 100 days, which assigned mostly to frozen 200 days. Morphometric comparisons using frozen fish must be done on fish frozen for identical periods of time to avoid biases related to the length of time they were frozen. Similar experiments should be conducted on other species and also using formalin- and alcohol-preserved specimens.

Ocean surface partitioning strategies using ocean colour remote Sensing: A review

NASA Astrophysics Data System (ADS)

Krug, Lilian Anne; Platt, Trevor; Sathyendranath, Shubha; Barbosa, Ana B.

2017-06-01

The ocean surface is organized into regions with distinct properties reflecting the complexity of interactions between environmental forcing and biological responses. The delineation of these functional units, each with unique, homogeneous properties and underlying ecosystem structure and dynamics, can be defined as ocean surface partitioning. The main purposes and applications of ocean partitioning include the evaluation of particular marine environments; generation of more accurate satellite ocean colour products; assimilation of data into biogeochemical and climate models; and establishment of ecosystem-based management practices. This paper reviews the diverse approaches implemented for ocean surface partition into functional units, using ocean colour remote sensing (OCRS) data, including their purposes, criteria, methods and scales. OCRS offers a synoptic, high spatial-temporal resolution, multi-decadal coverage of bio-optical properties, relevant to the applications and value of ocean surface partitioning. In combination with other biotic and/or abiotic data, OCRS-derived data (e.g., chlorophyll-a, optical properties) provide a broad and varied source of information that can be analysed using different delineation methods derived from subjective, expert-based to unsupervised learning approaches (e.g., cluster, fuzzy and empirical orthogonal function analyses). Partition schemes are applied at global to mesoscale spatial coverage, with static (time-invariant) or dynamic (time-varying) representations. A case study, the highly heterogeneous area off SW Iberian Peninsula (NE Atlantic), illustrates how the selection of spatial coverage and temporal representation affects the discrimination of distinct environmental drivers of phytoplankton variability. Advances in operational oceanography and in the subject area of satellite ocean colour, including development of new sensors, algorithms and products, are among the potential benefits from extended use, scope and

Ocean acidification postcards

USGS Publications Warehouse

Schreppel, Heather A.; Cimitile, Matthew J.

2011-01-01

The U.S. Geological Survey (USGS) is conducting research on ocean acidification in polar, temperate, subtropical, and tropical regions including the Arctic, West Florida Shelf, and the Caribbean. Project activities include field assessment, experimental laboratory studies, and evaluation of existing data. The USGS is participating in international and interagency working groups to develop research strategies to increase understanding of the global implications of ocean acidification. Research strategies include new approaches for seawater chemistry observation and modeling, assessment of physiological effects on organisms, changes in marine ecosystem structure, new technologies, and information resources. These postcards highlight ongoing USGS research efforts in ocean acidification and carbon cycling in marine and coastal ecosystems in three different regions: polar, temperate, and tropical. To learn more about ocean acidification visit: http://coastal.er.usgs.gov/ocean-acidification/.

Ocean Optics Protocols for Satellite Ocean Color Sensor Validation. Volume 6; Special Topics in Ocean Optics Protocols and Appendices; Revised

NASA Technical Reports Server (NTRS)

Mueller, J. L. (Editor); Fargion, Giulietta S. (Editor); McClain, Charles R. (Editor)

2003-01-01

This document stipulates protocols for measuring bio-optical and radiometric data for the Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) Project activities and algorithm development. The document is organized into 6 separate volumes as Ocean Optics Protocols for Satellite Ocean Color Sensor Validation, Revision 4. Volume I: Introduction, Background and Conventions; Volume II: Instrument Specifications, Characterization and Calibration; Volume III: Radiometric Measurements and Data Analysis Methods; Volume IV: Inherent Optical Properties: Instruments, Characterization, Field Measurements and Data Analysis Protocols; Volume V: Biogeochemical and Bio-Optical Measurements and Data Analysis Methods; Volume VI: Special Topics in Ocean Optics Protocols and Appendices. The earlier version of Ocean Optics Protocols for Satellite Ocean Color Sensor Validation, Revision 3 (Mueller and Fargion 2002, Volumes 1 and 2) is entirely superseded by the six volumes of Revision 4 listed above.

Spotlight on fish: light pollution affects circadian rhythms of European perch but does not cause stress.

PubMed

Brüning, Anika; Hölker, Franz; Franke, Steffen; Preuer, Torsten; Kloas, Werner

2015-04-01

Flora and fauna evolved under natural day and night cycles. However, natural light is now enhanced by artificial light at night, particularly in urban areas. This alteration of natural light environments during the night is hypothesised to alter biological rhythms in fish, by effecting night-time production of the hormone melatonin. Artificial light at night is also expected to increase the stress level of fish, resulting in higher cortisol production. In laboratory experiments, European perch (Perca fluviatilis) were exposed to four different light intensities during the night, 0 lx (control), 1 lx (potential light level in urban waters), 10 lx (typical street lighting at night) and 100 lx. Melatonin and cortisol concentrations were measured from water samples every 3h during a 24 hour period. This study revealed that the nocturnal increase in melatonin production was inhibited even at the lowest light level of 1 lx. However, cortisol levels did not differ between control and treatment illumination levels. We conclude that artificial light at night at very low intensities may disturb biological rhythms in fish since nocturnal light levels around 1 lx are already found in urban waters. However, enhanced stress induction could not be demonstrated. Copyright © 2014 Elsevier B.V. All rights reserved.

Nonuniform ocean acidification and attenuation of the ocean carbon sink

NASA Astrophysics Data System (ADS)

Fassbender, Andrea J.; Sabine, Christopher L.; Palevsky, Hilary I.

2017-08-01

Surface ocean carbon chemistry is changing rapidly. Partial pressures of carbon dioxide gas (pCO2) are rising, pH levels are declining, and the ocean's buffer capacity is eroding. Regional differences in short-term pH trends primarily have been attributed to physical and biological processes; however, heterogeneous seawater carbonate chemistry may also be playing an important role. Here we use Surface Ocean CO2 Atlas Version 4 data to develop 12 month gridded climatologies of carbonate system variables and explore the coherent spatial patterns of ocean acidification and attenuation in the ocean carbon sink caused by rising atmospheric pCO2. High-latitude regions exhibit the highest pH and buffer capacity sensitivities to pCO2 increases, while the equatorial Pacific is uniquely insensitive due to a newly defined aqueous CO2 concentration effect. Importantly, dissimilar regional pH trends do not necessarily equate to dissimilar acidity ([H+]) trends, indicating that [H+] is a more useful metric of acidification.

Ejecta from Ocean Impacts

NASA Technical Reports Server (NTRS)

Kyte, Frank T.

2003-01-01

Numerical simulations of deep-ocean impact provide some limits on the size of a projectile that will not mix with the ocean floor during a deep-ocean impact. For a vertical impact at asteroidal velocities (approx. 20 km/s), mixing is only likely when the projectile diameter is greater than 112 of the water depth. For oblique impacts, even larger projectiles will not mix with ocean floor silicates. Given the typical water depths of 4 to 5 km in deep-ocean basins, asteroidal projectiles with diameters as large as 2 or 3 km may commonly produce silicate ejecta that is composed only of meteoritic materials and seawater salts. However, the compressed water column beneath the projectile can still disrupt and shock metamorphose the ocean floor. Therefore, production of a separate, terrestrial ejecta component is not ruled out in the most extreme case. With increasing projectile size (or energy) relative to water depths, there must be a gradation between oceanic impacts and more conventional continental impacts. Given that 60% of the Earth's surface is covered by oceanic lithosphere and 500 m projectiles impact the Earth on 10(exp 5) y timescales, there must be hundreds of oceanic impact deposits in the sediment record awaiting discovery.

Comparison of Two Global Ocean Reanalyses, NRL Global Ocean Forecast System (GOFS) and U. Maryland Simple Ocean Data Assimilation (SODA)

NASA Astrophysics Data System (ADS)

Richman, J. G.; Shriver, J. F.; Metzger, E. J.; Hogan, P. J.; Smedstad, O. M.

2017-12-01

The Oceanography Division of the Naval Research Laboratory recently completed a 23-year (1993-2015) coupled ocean-sea ice reanalysis forced by NCEP CFS reanalysis fluxes. The reanalysis uses the Global Ocean Forecast System (GOFS) framework of the HYbrid Coordinate Ocean Model (HYCOM) and the Los Alamos Community Ice CodE (CICE) and the Navy Coupled Ocean Data Assimilation 3D Var system (NCODA). The ocean model has 41 layers and an equatorial resolution of 0.08° (8.8 km) on a tri-polar grid with the sea ice model on the same grid that reduces to 3.5 km at the North Pole. Sea surface temperature (SST), sea surface height (SSH) and temperature-salinity profile data are assimilated into the ocean every day. The SSH anomalies are converted into synthetic profiles of temperature and salinity prior to assimilation. Incremental analysis updating of geostrophically balanced increments is performed over a 6-hour insertion window. Sea ice concentration is assimilated into the sea ice model every day. Following the lead of the Ocean Reanalysis Intercomparison Project (ORA-IP), the monthly mean upper ocean heat and salt content from the surface to 300 m, 700m and 1500 m, the mixed layer depth, the depth of the 20°C isotherm, the steric sea surface height and the Atlantic Meridional Overturning Circulation for the GOFS reanalysis and the Simple Ocean Data Assimilation (SODA 3.3.1) eddy-permitting reanalysis have been compared on a global uniform 0.5° grid. The differences between the two ocean reanalyses in heat and salt content increase with increasing integration depth. Globally, GOFS trends to be colder than SODA at all depth. Warming trends are observed at all depths over the 23 year period. The correlation of the upper ocean heat content is significant above 700 m. Prior to 2004, differences in the data assimilated lead to larger biases. The GOFS reanalysis assimilates SSH as profile data, while SODA doesn't. Large differences are found in the Western Boundary Currents

Slow and Steady: Ocean Circulation. The Influence of Sea Surface Height on Ocean Currents

NASA Technical Reports Server (NTRS)

Haekkinen, Sirpa

2000-01-01

The study of ocean circulation is vital to understanding how our climate works. The movement of the ocean is closely linked to the progression of atmospheric motion. Winds close to sea level add momentum to ocean surface currents. At the same time, heat that is stored and transported by the ocean warms the atmosphere above and alters air pressure distribution. Therefore, any attempt to model climate variation accurately must include reliable calculations of ocean circulation. Unlike movement of the atmosphere, movement of the ocean's waters takes place mostly near the surface. The major patterns of surface circulation form gigantic circular cells known as gyres. They are categorized according to their general location-equatorial, subtropical, subpolar, and polar-and may run across an entire ocean. The smaller-scale cell of ocean circulation is known' as an eddy. Eddies are much more common than gyres and much more difficult to track in computer simulations of ocean currents.

A global ocean climatology of preindustrial and modern ocean δ13C

NASA Astrophysics Data System (ADS)

Eide, Marie; Olsen, Are; Ninnemann, Ulysses S.; Johannessen, Truls

2017-03-01

We present a global ocean climatology of dissolved inorganic carbon δ13C (‰) corrected for the 13C-Suess effect, preindustrial δ13C. This was constructed by first using Olsen and Ninnemann's (2010) back-calculation method on data from 25 World Ocean Circulation Experiment cruises to reconstruct the preindustrial δ13C on sections spanning all major oceans. Next, we developed five multilinear regression equations, one for each major ocean basin, which were applied on the World Ocean Atlas data to construct the climatology. This reveals the natural δ13C distribution in the global ocean. Compared to the modern distribution, the preindustrial δ13C spans a larger range of values. The maxima, of up to 1.8‰, occurs in the subtropical gyres of all basins, in the upper and intermediate waters of the North Atlantic, as well as in mode waters with a Southern Ocean origin. Particularly strong gradients occur at intermediate depths, revealing a strong potential for using δ13C as a tracer for changes in water mass geometry at these levels. Further, we identify a much tighter relationship between δ13C and apparent oxygen utilization (AOU) than between δ13C and phosphate. This arises because, in contrast to phosphate, AOU and δ13C are both partly reset when waters are ventilated in the Southern Ocean and underscore that δ13C is a highly robust proxy for past changes in ocean oxygen content and ocean ventilation. Our global preindustrial δ13C climatology is openly accessible and can be used, for example, for improved model evaluation and interpretation of sediment δ13C records.

Global declines in oceanic nitrification rates as a consequence of ocean acidification.

PubMed

Beman, J Michael; Chow, Cheryl-Emiliane; King, Andrew L; Feng, Yuanyuan; Fuhrman, Jed A; Andersson, Andreas; Bates, Nicholas R; Popp, Brian N; Hutchins, David A

2011-01-04

Ocean acidification produced by dissolution of anthropogenic carbon dioxide (CO(2)) emissions in seawater has profound consequences for marine ecology and biogeochemistry. The oceans have absorbed one-third of CO(2) emissions over the past two centuries, altering ocean chemistry, reducing seawater pH, and affecting marine animals and phytoplankton in multiple ways. Microbially mediated ocean biogeochemical processes will be pivotal in determining how the earth system responds to global environmental change; however, how they may be altered by ocean acidification is largely unknown. We show here that microbial nitrification rates decreased in every instance when pH was experimentally reduced (by 0.05-0.14) at multiple locations in the Atlantic and Pacific Oceans. Nitrification is a central process in the nitrogen cycle that produces both the greenhouse gas nitrous oxide and oxidized forms of nitrogen used by phytoplankton and other microorganisms in the sea; at the Bermuda Atlantic Time Series and Hawaii Ocean Time-series sites, experimental acidification decreased ammonia oxidation rates by 38% and 36%. Ammonia oxidation rates were also strongly and inversely correlated with pH along a gradient produced in the oligotrophic Sargasso Sea (r(2) = 0.87, P < 0.05). Across all experiments, rates declined by 8-38% in low pH treatments, and the greatest absolute decrease occurred where rates were highest off the California coast. Collectively our results suggest that ocean acidification could reduce nitrification rates by 3-44% within the next few decades, affecting oceanic nitrous oxide production, reducing supplies of oxidized nitrogen in the upper layers of the ocean, and fundamentally altering nitrogen cycling in the sea.

Global declines in oceanic nitrification rates as a consequence of ocean acidification

PubMed Central

Beman, J. Michael; Chow, Cheryl-Emiliane; King, Andrew L.; Feng, Yuanyuan; Fuhrman, Jed A.; Andersson, Andreas; Bates, Nicholas R.; Popp, Brian N.; Hutchins, David A.

2011-01-01

Ocean acidification produced by dissolution of anthropogenic carbon dioxide (CO2) emissions in seawater has profound consequences for marine ecology and biogeochemistry. The oceans have absorbed one-third of CO2 emissions over the past two centuries, altering ocean chemistry, reducing seawater pH, and affecting marine animals and phytoplankton in multiple ways. Microbially mediated ocean biogeochemical processes will be pivotal in determining how the earth system responds to global environmental change; however, how they may be altered by ocean acidification is largely unknown. We show here that microbial nitrification rates decreased in every instance when pH was experimentally reduced (by 0.05–0.14) at multiple locations in the Atlantic and Pacific Oceans. Nitrification is a central process in the nitrogen cycle that produces both the greenhouse gas nitrous oxide and oxidized forms of nitrogen used by phytoplankton and other microorganisms in the sea; at the Bermuda Atlantic Time Series and Hawaii Ocean Time-series sites, experimental acidification decreased ammonia oxidation rates by 38% and 36%. Ammonia oxidation rates were also strongly and inversely correlated with pH along a gradient produced in the oligotrophic Sargasso Sea (r2 = 0.87, P < 0.05). Across all experiments, rates declined by 8–38% in low pH treatments, and the greatest absolute decrease occurred where rates were highest off the California coast. Collectively our results suggest that ocean acidification could reduce nitrification rates by 3–44% within the next few decades, affecting oceanic nitrous oxide production, reducing supplies of oxidized nitrogen in the upper layers of the ocean, and fundamentally altering nitrogen cycling in the sea. PMID:21173255

Formation of perched lava ponds on basaltic volcanoes: Interaction between cooling rate and flow geometry allows estimation of lava effusion rates

NASA Technical Reports Server (NTRS)

Wilson, L.; Parfitt, E. A.

1993-01-01

Perched lava ponds are infrequent but distinctive topographic features formed during some basaltic eruptions. Two such ponds, each approximately 150 m in diameter, formed during the 1968 eruption at Napau Crater and the 1974 eruption of Mauna Ulu, both on Kilauea Volcano, Hawaii. Each one formed where a channelized, high volume flux lava flow encountered a sharp reduction of slope: the flow spread out radially and stalled, forming a well-defined terminal levee enclosing a nearly circular lava pond. We describe a model of how cooling limits the motion of lava spreading radially into a pond and compare this with the case of a channelized flow. The difference in geometry has a major effect, such that the size of a pond is a good indicator of the volume flux of the lava forming it. Lateral spreading on distal shallow slopes is a major factor limiting the lengths of lava flows.

Supplementation of lactobacilli improves growth, regulates microbiota composition and suppresses skeletal anomalies in juvenile pike-perch (Sander lucioperca) reared in recirculating aquaculture system (RAS): A pilot study.

PubMed

Ljubobratovic, Uros; Kosanovic, Dejana; Vukotic, Goran; Molnar, Zsuzsanna; Stanisavljevic, Nemanja; Ristovic, Tijana; Peter, Geza; Lukic, Jovanka; Jeney, Galina

2017-12-01

This research aimed to test the effects of lactobacilli, applied to cultured pike-perch, either through hydrolyzed OTOHIME fish diet, or through Artemia nauplii, on fish growth, microbiota balance and skeletal development. On the 12th Day Post Hatching (DPH) fish were divided into following treatment groups: two groups received the combination of OTOHIME and nauplii enriched either with Lactobacillus paracasei BGHN14+Lactobacillus rhamnosus BGT10 or with Lactobacillus reuteri BGGO6-55+Lactobacillus salivarius BGHO1, and one group received OTOHIME hydrolyzed by BGHN14+BGT10 and non-enriched nauplii. Control group received non-enriched nauplii and non-hydrolyzed OTOHIME. The treatment lasted 14days and fish were sacrificed on the 26th DPH for the assessment of digestive enzyme activity and microbiota composition. Individual total lengths and individual body weights were recorded at the end of the treatments, on the 26th DPH, and also on the 45th DPH, in parallel with the evaluation of skeletal deformities and fish survival. Our results indicated positive effect of Artemia enriched with BGGO6-55+BGHO1 on fish growth, skeletal development and trypsin to chymotrypsin activity ratio (T/C), as an indicator of protein digestibility. Hydrolysis of OTOHIME was also associated with better skeletal development, higher T/C values and lower levels of Aeromonas and Mycobacterium spp., which are important fish pathogens. Though additional testing in larger cohort studies is needed, these observations are promising in terms of usage of probiotics for improved environmentally friendly production of pike-perch in Recirculating Aquaculture System (RAS). Copyright © 2017 Elsevier Ltd. All rights reserved.

Oceanic Precondition and Evolution of the Indian Ocean Dipole Events

NASA Astrophysics Data System (ADS)

Horii, T.; Masumoto, Y.; Ueki, I.; Hase, H.; Mizuno, K.

2008-12-01

Indian Ocean Dipole (IOD) is one of the interannual climate variability in the Indian Ocean, associated with the negative (positive) SST anomaly in the eastern (western) equatorial region developing during boreal summer/autumn seasons. Japan Agency for Marine-Earth Science and Technology (JAMSTEC) has been deploying TRITON buoys in the eastern equatorial Indian Ocean since October 2001. Details of subsurface ocean conditions associated with IOD events were observed by the mooring buoys in the eastern equatorial Indian Ocean in 2006, 2007, and 2008. In the 2006 IOD event, large-scale sea surface signals in the tropical Indian Ocean associated with the positive IOD started in August 2006, and the anomalous conditions continued until December 2006. Data from the mooring buoys, however, captured the first appearance of the negative temperature anomaly at the thermocline depth with strong westward current anomalies in May 2006, about three months earlier than the development of the surface signatures. Similar appearance of negative temperature anomalies in the subsurface were also observed in 2007 and 2008, while the amplitude, the timing, and the relation to the surface layer were different among the events. The implications of the subsurface conditions for the occurrences of these IOD events are discussed.

33 CFR 165.T05-0494 - Safety Zone, Atlantic Ocean; Ocean City, NJ.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Safety Zone, Atlantic Ocean; Ocean City, NJ. 165.T05-0494 Section 165.T05-0494 Navigation and Navigable Waters COAST GUARD... § 165.T05-0494 Safety Zone, Atlantic Ocean; Ocean City, NJ. (a) Location. The following area is a safety...

Inter comparison of Tropical Indian Ocean features in different ocean reanalysis products

NASA Astrophysics Data System (ADS)

Karmakar, Ananya; Parekh, Anant; Chowdary, J. S.; Gnanaseelan, C.

2017-09-01

This study makes an inter comparison of ocean state of the Tropical Indian Ocean (TIO) in different ocean reanalyses such as global ocean data assimilation system (GODAS), ensemble coupled data assimilation (ECDA), ocean reanalysis system 4 (ORAS4) and simple ocean data assimilation (SODA) with reference to the in-situ buoy observations, satellite observed sea surface temperature (SST), EN4 analysis and ocean surface current analysis real time (OSCAR). Analysis of mean state of SST and sea surface salinity (SSS) reveals that ORAS4 is better comparable with satellite observations as well as EN4 analysis, and is followed by SODA, ECDA and GODAS. The surface circulation in ORAS4 is closer to OSCAR compared to the other reanalyses. However mixed layer depth (MLD) is better simulated by SODA, followed by ECDA, ORAS4 and GODAS. Seasonal evolution of error indicates that the highest deviation in SST and MLD over the TIO exists during spring and summer in GODAS. Statistical analysis with concurrent data of EN4 for the period of 1980-2010 supports that the difference and standard deviation (variability strength) ratio for SSS and MLD is mostly greater than one. In general the strength of variability is overestimated by all the reanalyses. Further comparison with in-situ buoy observations supports that MLD errors over the equatorial Indian Ocean (EIO) and the Bay of Bengal are higher than with EN4 analysis. Overall ORAS4 displays higher correlation and lower error among all reanalyses with respect to both EN4 analysis and buoy observations. Major issues in the reanalyses are the underestimation of upper ocean stability in the TIO, underestimation of surface current in the EIO, overestimation of vertical shear of current and improper variability in different oceanic variables. To improve the skill of reanalyses over the TIO, salinity vertical structure and upper ocean circulation need to be better represented in reanalyses.

Consensuses and discrepancies of basin-scale ocean heat content changes in different ocean analyses

NASA Astrophysics Data System (ADS)

Wang, Gongjie; Cheng, Lijing; Abraham, John; Li, Chongyin

2018-04-01

Inconsistent global/basin ocean heat content (OHC) changes were found in different ocean subsurface temperature analyses, especially in recent studies related to the slowdown in global surface temperature rise. This finding challenges the reliability of the ocean subsurface temperature analyses and motivates a more comprehensive inter-comparison between the analyses. Here we compare the OHC changes in three ocean analyses (Ishii, EN4 and IAP) to investigate the uncertainty in OHC in four major ocean basins from decadal to multi-decadal scales. First, all products show an increase of OHC since 1970 in each ocean basin revealing a robust warming, although the warming rates are not identical. The geographical patterns, the key modes and the vertical structure of OHC changes are consistent among the three datasets, implying that the main OHC variabilities can be robustly represented. However, large discrepancies are found in the percentage of basinal ocean heating related to the global ocean, with the largest differences in the Pacific and Southern Ocean. Meanwhile, we find a large discrepancy of ocean heat storage in different layers, especially within 300-700 m in the Pacific and Southern Oceans. Furthermore, the near surface analysis of Ishii and IAP are consistent with sea surface temperature (SST) products, but EN4 is found to underestimate the long-term trend. Compared with ocean heat storage derived from the atmospheric budget equation, all products show consistent seasonal cycles of OHC in the upper 1500 m especially during 2008 to 2012. Overall, our analyses further the understanding of the observed OHC variations, and we recommend a careful quantification of errors in the ocean analyses.

Ocean Observations of Climate Change

NASA Astrophysics Data System (ADS)

Chambers, Don

2016-01-01

The ocean influences climate by storing and transporting large amounts of heat, freshwater, and carbon, and exchanging these properties with the atmosphere. About 93% of the excess heat energy stored by the earth over the last 50 years is found in the ocean. More than three quarters of the total exchange of water between the atmosphere and the earth's surface through evaporation and precipitation takes place over the oceans. The ocean contains 50 times more carbon than the atmosphere and is at present acting to slow the rate of climate change by absorbing one quarter of human emissions of carbon dioxide from fossil fuel burning, cement production, deforestation and other land use change.Here I summarize the observational evidence of change in the ocean, with an emphasis on basin- and global-scale changes relevant to climate. These include: changes in subsurface ocean temperature and heat content, evidence for regional changes in ocean salinity and their link to changes in evaporation and precipitation over the oceans, evidence of variability and change of ocean current patterns relevant to climate, observations of sea level change and predictions over the next century, and biogeochemical changes in the ocean, including ocean acidification.

Global Ocean Currents Database

NASA Astrophysics Data System (ADS)

Boyer, T.; Sun, L.

2016-02-01

The NOAA's National Centers for Environmental Information has released an ocean currents database portal that aims 1) to integrate global ocean currents observations from a variety of instruments with different resolution, accuracy and response to spatial and temporal variability into a uniform network common data form (NetCDF) format and 2) to provide a dedicated online data discovery, access to NCEI-hosted and distributed data sources for ocean currents data. The portal provides a tailored web application that allows users to search for ocean currents data by platform types and spatial/temporal ranges of their interest. The dedicated web application is available at http://www.nodc.noaa.gov/gocd/index.html. The NetCDF format supports widely-used data access protocols and catalog services such as OPeNDAP (Open-source Project for a Network Data Access Protocol) and THREDDS (Thematic Real-time Environmental Distributed Data Services), which the GOCD users can use data files with their favorite analysis and visualization client software without downloading to their local machine. The potential users of the ocean currents database include, but are not limited to, 1) ocean modelers for their model skills assessments, 2) scientists and researchers for studying the impact of ocean circulations on the climate variability, 3) ocean shipping industry for safety navigation and finding optimal routes for ship fuel efficiency, 4) ocean resources managers while planning for the optimal sites for wastes and sewages dumping and for renewable hydro-kinematic energy, and 5) state and federal governments to provide historical (analyzed) ocean circulations as an aid for search and rescue

Global Ocean Phytoplankton

NASA Technical Reports Server (NTRS)

Franz, B. A.; Behrenfeld, M. J.; Siegel, D. A.; Werdell, P. J.

2013-01-01

Phytoplankton are free-floating algae that grow in the euphotic zone of the upper ocean, converting carbon dioxide, sunlight, and available nutrients into organic carbon through photosynthesis. Despite their microscopic size, these photoautotrophs are responsible for roughly half the net primary production on Earth (NPP; gross primary production minus respiration), fixing atmospheric CO2 into food that fuels our global ocean ecosystems. Phytoplankton thus play a critical role in the global carbon cycle, and their growth patterns are highly sensitive to environmental changes such as increased ocean temperatures that stratify the water column and prohibit the transfer of cold, nutrient richwaters to the upper ocean euphotic zone.

Mesoscale atmosphere ocean coupling enhances the transfer of wind energy into the ocean

PubMed Central

Byrne, D.; Münnich, M.; Frenger, I.; Gruber, N.

2016-01-01

Although it is well established that the large-scale wind drives much of the world's ocean circulation, the contribution of the wind energy input at mesoscales (10–200 km) remains poorly known. Here we use regional simulations with a coupled high-resolution atmosphere–ocean model of the South Atlantic, to show that mesoscale ocean features and, in particular, eddies can be energized by their thermodynamic interactions with the atmosphere. Owing to their sea-surface temperature anomalies affecting the wind field above them, the oceanic eddies in the presence of a large-scale wind gradient provide a mesoscale conduit for the transfer of energy into the ocean. Our simulations show that this pathway is responsible for up to 10% of the kinetic energy of the oceanic mesoscale eddy field in the South Atlantic. The conditions for this pathway to inject energy directly into the mesoscale prevail over much of the Southern Ocean north of the Polar Front. PMID:27292447

Turbulent flow reduces oxygen consumption in the labriform swimming shiner perch, Cymatogaster aggregata.

PubMed

van der Hoop, Julie M; Byron, Margaret L; Ozolina, Karlina; Miller, David L; Johansen, Jacob L; Domenici, Paolo; Steffensen, John F

2018-06-12

Fish swimming energetics are often measured in laboratory environments which attempt to minimize turbulence, though turbulent flows are common in the natural environment. To test whether the swimming energetics and kinematics of shiner perch, Cymatogaster aggregata (a labriform swimmer), were affected by turbulence, two flow conditions were constructed in a swim-tunnel respirometer. A low-turbulence flow was created using a common swim-tunnel respirometry setup with a flow straightener and fine-mesh grid to minimize velocity fluctuations. A high-turbulence flow condition was created by allowing large velocity fluctuations to persist without a flow straightener or fine grid. The two conditions were tested with particle image velocimetry to confirm significantly different turbulence properties throughout a range of mean flow speeds. Oxygen consumption rate of the swimming fish increased with swimming speed and pectoral fin beat frequency in both flow conditions. Higher turbulence also caused a greater positional variability in swimming individuals (versus low-turbulence flow) at medium and high speeds. Surprisingly, fish used less oxygen in high-turbulence compared with low-turbulence flow at medium and high swimming speeds. Simultaneous measurements of swimming kinematics indicated that these reductions in oxygen consumption could not be explained by specific known flow-adaptive behaviours such as Kármán gaiting or entraining. Therefore, fish in high-turbulence flow may take advantage of the high variability in turbulent energy through time. These results suggest that swimming behaviour and energetics measured in the lab in straightened flow, typical of standard swimming respirometers, might differ from that of more turbulent, semi-natural flow conditions. © 2018. Published by The Company of Biologists Ltd.

Learn about Ocean Dumping

EPA Pesticide Factsheets

Ocean dumping is regulated by the Marine Protection, Research and Sanctuaries Act (MPRSA). Learn about ocean dumping regulation including what materials can and cannot be dumped, the Ocean Dumping Management Program, and MPRSA history and accomplishments.

The Role and Variability of Ocean Heat Content in the Arctic Ocean: 1948-2009

DTIC Science & Technology

2014-06-01

moved from the Bering Sea past the Bering Strait into the Beaufort Sea (Logerwell 2008). However, besides the risks of ocean acidification and...VARIABILITY OF OCEAN HEAT CONTENT IN THE ARCTIC OCEAN : 1948–2009 by Dominic F. DiMaggio June 2014 Thesis Co-Advisors: Wieslaw Maslowski...COVERED Master’s Thesis 4. TITLE AND SUBTITLE THE ROLE AND VARIABILITY OF OCEAN HEAT CONTENT IN THE ARCTIC OCEAN : 1948–2009 5. FUNDING NUMBERS 6

OceanNOMADS: Real-time and retrospective access to operational U.S. ocean prediction products

NASA Astrophysics Data System (ADS)

Harding, J. M.; Cross, S. L.; Bub, F.; Ji, M.

2011-12-01

The National Oceanic and Atmospheric Administration (NOAA) National Operational Model Archive and Distribution System (NOMADS) provides both real-time and archived atmospheric model output from servers at the National Centers for Environmental Prediction (NCEP) and National Climatic Data Center (NCDC) respectively (http://nomads.ncep.noaa.gov/txt_descriptions/marRutledge-1.pdf). The NOAA National Ocean Data Center (NODC) with NCEP is developing a complementary capability called OceanNOMADS for operational ocean prediction models. An NCEP ftp server currently provides real-time ocean forecast output (http://www.opc.ncep.noaa.gov/newNCOM/NCOM_currents.shtml) with retrospective access through NODC. A joint effort between the Northern Gulf Institute (NGI; a NOAA Cooperative Institute) and the NOAA National Coastal Data Development Center (NCDDC; a division of NODC) created the developmental version of the retrospective OceanNOMADS capability (http://www.northerngulfinstitute.org/edac/ocean_nomads.php) under the NGI Ecosystem Data Assembly Center (EDAC) project (http://www.northerngulfinstitute.org/edac/). Complementary funding support for the developmental OceanNOMADS from U.S. Integrated Ocean Observing System (IOOS) through the Southeastern University Research Association (SURA) Model Testbed (http://testbed.sura.org/) this past year provided NODC the analogue that facilitated the creation of an NCDDC production version of OceanNOMADS (http://www.ncddc.noaa.gov/ocean-nomads/). Access tool development and storage of initial archival data sets occur on the NGI/NCDDC developmental servers with transition to NODC/NCCDC production servers as the model archives mature and operational space and distribution capability grow. Navy operational global ocean forecast subsets for U.S waters comprise the initial ocean prediction fields resident on the NCDDC production server. The NGI/NCDDC developmental server currently includes the Naval Research Laboratory Inter-America Seas

Oceanic Platform of the Canary Islands: an ocean testbed for ocean energy converters

NASA Astrophysics Data System (ADS)

González, Javier; Hernández-Brito, Joaquín.; Llinás, Octavio

2010-05-01

The Oceanic Platform of the Canary Islands (PLOCAN) is a Governmental Consortium aimed to build and operate an off-shore infrastructure to facilitate the deep sea research and speed up the technology associated. This Consortium is overseen by the Spanish Ministry of Science and Innovation and the Canarian Agency for Research and Innovation. The infrastructure consists of an oceanic platform located in an area with depths between 50-100 meters, close to the continental slope and four kilometers off the coast of Gran Canaria, in the archipelago of the Canary Islands. The process of construction will start during the first months of 2010 and is expected to be finished in mid-year 2011. PLOCAN serves five strategic lines: an integral observatory able to explore from the deep ocean to the atmosphere, an ocean technology testbed, a base for underwater vehicles, an innovation platform and a highly specialized training centre. Ocean energy is a suitable source to contribute the limited mix-energy conformed in the archipelago of the Canary Islands with a total population around 2 million people unequally distributed in seven islands. Islands of Gran Canaria and Tenerife support the 80% of the total population with 800.000 people each. PLOCAN will contribute to develop the ocean energy sector establishing a marine testbed allowing prototypes testing at sea under a meticulous monitoring network provided by the integral observatory, generating valuable information to developers. Reducing costs throughout an integral project management is an essential objective to be reach, providing services such as transportation, customs and administrative permits. Ocean surface for testing activities is around 8 km2 with a depth going from 50 to 100 meters, 4km off the coast. Selected areas for testing have off-shore wind power conditions around 500-600 W/m2 and wave power conditions around 6 kW/m in the East coast and 10 kW/m in the North coast. Marine currents in the Canary Islands are

Regional Ocean Data Assimilation

NASA Astrophysics Data System (ADS)

Edwards, Christopher A.; Moore, Andrew M.; Hoteit, Ibrahim; Cornuelle, Bruce D.

2015-01-01

This article reviews the past 15 years of developments in regional ocean data assimilation. A variety of scientific, management, and safety-related objectives motivate marine scientists to characterize many ocean environments, including coastal regions. As in weather prediction, the accurate representation of physical, chemical, and/or biological properties in the ocean is challenging. Models and observations alone provide imperfect representations of the ocean state, but together they can offer improved estimates. Variational and sequential methods are among the most widely used in regional ocean systems, and there have been exciting recent advances in ensemble and four-dimensional variational approaches. These techniques are increasingly being tested and adapted for biogeochemical applications.

Regional ocean data assimilation.

PubMed

Edwards, Christopher A; Moore, Andrew M; Hoteit, Ibrahim; Cornuelle, Bruce D

2015-01-01

This article reviews the past 15 years of developments in regional ocean data assimilation. A variety of scientific, management, and safety-related objectives motivate marine scientists to characterize many ocean environments, including coastal regions. As in weather prediction, the accurate representation of physical, chemical, and/or biological properties in the ocean is challenging. Models and observations alone provide imperfect representations of the ocean state, but together they can offer improved estimates. Variational and sequential methods are among the most widely used in regional ocean systems, and there have been exciting recent advances in ensemble and four-dimensional variational approaches. These techniques are increasingly being tested and adapted for biogeochemical applications.

Deep Water Ocean Acoustics

DTIC Science & Technology

2015-07-17

under- ice scattering, bathymetric diffraction and the application of the ocean acoustic Parabolic Equation to infrasound. 2. Tasks a. Task 1...and Climate of the Ocean, Phase II (ECCO2): High-Resolution Global-Ocean and Sea- Ice Data Synthesis) model re- analysis for the years 1992 and 1993...The ECCO2 model is a state estimation based upon data syntheses obtained by least squares fitting of the global ocean and sea- ice configuration of

Spaceborne Studies Of Ocean Circulation

NASA Astrophysics Data System (ADS)

Patzert, William C.

1984-08-01

The global view of the oceans seen by Seasat during its 1978 flight demonstrated the feasibility of ocean remote sensing. These first-ever global data sets of sea surface topography (altimeter) and marine winds (scatterometer) laid the foundation for two satellite missions planned for the late 1980's. The future missions are the next generation of altimeter and scatterometer to be flown aboard TOPEX (Topography Experiment) and NROSS (Navy Remote Ocean Sensing System), respectively. The data from these satellites will be coordinated with measurements made at sea to determine the driving forces of ocean circulation and to study the oceans role in climate variability. Sea surface winds (calculated from scatterometer measurements) are the fundamental driving force for ocean waves and currents (estimated from altimeter measurements). On a global scale, the winds and currents are approximately equal partners in redistributing the excess heat gained in the tropics from solar radiation to the cooler polar regions. Small perturbations in this system can dramatically alter global weather, such as the El Niho event of 1982-83. During an El Ni?io event, global wind patterns and ocean currents are perturbed causing unusual ocean warming in the tropical Pacfic Ocean. These ocean events are coupled to complex fluctuations in global weather. Only with satellites will we be able to collect the global data sets needed to study events such as El Ni?o. When TOPEX and NROSS fly, oceanographers will have the equivalent of meteorological high and low pressure charts of ocean topography as well as the surface winds to study ocean "weather." This ability to measure ocean circulation and its driving forces is a critical element in understanding the influence of oceans on society. Climatic changes, fisheries, commerce, waste disposal, and national defense are all involved.

Remote Sensing of Ocean Color

NASA Astrophysics Data System (ADS)

Dierssen, Heidi M.; Randolph, Kaylan

The oceans cover over 70% of the earth's surface and the life inhabiting the oceans play an important role in shaping the earth's climate. Phytoplankton, the microscopic organisms in the surface ocean, are responsible for half of the photosynthesis on the planet. These organisms at the base of the food web take up light and carbon dioxide and fix carbon into biological structures releasing oxygen. Estimating the amount of microscopic phytoplankton and their associated primary productivity over the vast expanses of the ocean is extremely challenging from ships. However, as phytoplankton take up light for photosynthesis, they change the color of the surface ocean from blue to green. Such shifts in ocean color can be measured from sensors placed high above the sea on satellites or aircraft and is called "ocean color remote sensing." In open ocean waters, the ocean color is predominantly driven by the phytoplankton concentration and ocean color remote sensing has been used to estimate the amount of chlorophyll a, the primary light-absorbing pigment in all phytoplankton. For the last few decades, satellite data have been used to estimate large-scale patterns of chlorophyll and to model primary productivity across the global ocean from daily to interannual timescales. Such global estimates of chlorophyll and primary productivity have been integrated into climate models and illustrate the important feedbacks between ocean life and global climate processes. In coastal and estuarine systems, ocean color is significantly influenced by other light-absorbing and light-scattering components besides phytoplankton. New approaches have been developed to evaluate the ocean color in relationship to colored dissolved organic matter, suspended sediments, and even to characterize the bathymetry and composition of the seafloor in optically shallow waters. Ocean color measurements are increasingly being used for environmental monitoring of harmful algal blooms, critical coastal habitats

Does Southern Ocean Surface Forcing Shape the Global Ocean Overturning Circulation?

NASA Astrophysics Data System (ADS)

Sun, Shantong; Eisenman, Ian; Stewart, Andrew L.

2018-03-01

Paleoclimate proxy data suggest that the Atlantic Meridional Overturning Circulation (AMOC) was shallower at the Last Glacial Maximum (LGM) than its preindustrial (PI) depth. Previous studies have suggested that this shoaling necessarily accompanies Antarctic sea ice expansion at the LGM. Here the influence of Southern Ocean surface forcing on the AMOC depth is investigated using ocean-only simulations from a state-of-the-art climate model with surface forcing specified from the output of previous coupled PI and LGM simulations. In contrast to previous expectations, we find that applying LGM surface forcing in the Southern Ocean and PI surface forcing elsewhere causes the AMOC to shoal only about half as much as when LGM surface forcing is applied globally. We show that this occurs because diapycnal mixing renders the Southern Ocean overturning circulation more diabatic than previously assumed, which diminishes the influence of Southern Ocean surface buoyancy forcing on the depth of the AMOC.

The ocean mixed layer under Southern Ocean sea-ice: Seasonal cycle and forcing

NASA Astrophysics Data System (ADS)

Pellichero, Violaine; Sallée, Jean-Baptiste; Schmidtko, Sunke; Roquet, Fabien; Charrassin, Jean-Benoît

2017-02-01

The oceanic mixed layer is the gateway for the exchanges between the atmosphere and the ocean; in this layer, all hydrographic ocean properties are set for months to millennia. A vast area of the Southern Ocean is seasonally capped by sea-ice, which alters the characteristics of the ocean mixed layer. The interaction between the ocean mixed layer and sea-ice plays a key role for water mass transformation, the carbon cycle, sea-ice dynamics, and ultimately for the climate as a whole. However, the structure and characteristics of the under-ice mixed layer are poorly understood due to the sparseness of in situ observations and measurements. In this study, we combine distinct sources of observations to overcome this lack in our understanding of the polar regions. Working with elephant seal-derived, ship-based, and Argo float observations, we describe the seasonal cycle of the ocean mixed-layer characteristics and stability of the ocean mixed layer over the Southern Ocean and specifically under sea-ice. Mixed-layer heat and freshwater budgets are used to investigate the main forcing mechanisms of the mixed-layer seasonal cycle. The seasonal variability of sea surface salinity and temperature are primarily driven by surface processes, dominated by sea-ice freshwater flux for the salt budget and by air-sea flux for the heat budget. Ekman advection, vertical diffusivity, and vertical entrainment play only secondary roles. Our results suggest that changes in regional sea-ice distribution and annual duration, as currently observed, widely affect the buoyancy budget of the underlying mixed layer, and impact large-scale water mass formation and transformation with far reaching consequences for ocean ventilation.

Endocrine and metabolic dysfunction in yellow perch, Perca flavescens, exposed to organic contaminants and heavy metals in the St. Lawrence River

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hontela, A.; Duclos, D.; Fortin, R.

1995-04-01

The endocrine and biochemical responses to the acute stress of capture and handling were investigated in sexually mature and in immature male and female yellow perch, Perca flavescens, from a site contaminated by organic contaminants (PAHs and PCBs) and heavy metals (Hg, Cd, As, and Zn) and from a reference site in the St. Lawrence River. Following a standardized capture and handling stress, fish from the contaminated site did not exhibit the expected physiological stress response observed in fish from the reference site. Blood cortisol and thyroxine levels were lower, and liver glycogen stores were greater in mature males andmore » females, as well as in the immature fish from the contaminated site, compared to the reference site. Fish from the contaminated site also had smaller gonads and lower condition factor. The impaired ability to elevate blood cortisol in response to an acute stress may be used as a biomarker of toxic stress in health assessment of feral fish from polluted environments.« less

Activity Book: Ocean Ecology.

ERIC Educational Resources Information Center

Learning, 1992

1992-01-01

Presents a collection of activities to help elementary students study ocean ecology. The activities have students investigate ocean inhabitants, analyze animal adaptations, examine how temperature and saltiness affect ocean creatures, and learn about safeguarding the sea. Student pages offer reproducible learning sheets. (SM)

Methyl bromide: ocean sources, ocean sinks, and climate sensitivity

NASA Technical Reports Server (NTRS)

Anbar, A. D.; Yung, Y. L.; Chavez, F. P.

1996-01-01

The oceans play an important role in the geochemical cycle of methyl bromide (CH3Br), the major carrier of O3-destroying bromine to the stratosphere. The quantity of CH3Br produced annually in seawater is comparable to the amount entering the atmosphere each year from natural and anthropogenic sources. The production mechanism is unknown but may be biological. Most of this CH3Br is consumed in situ by hydrolysis or reaction with chloride. The size of the fraction which escapes to the atmosphere is poorly constrained; measurements in seawater and the atmosphere have been used to justify both a large oceanic CH3Br flux to the atmosphere and a small net ocean sink. Since the consumption reactions are extremely temperature-sensitive, small temperature variations have large effects on the CH3Br concentration in seawater, and therefore on the exchange between the atmosphere and the ocean. The net CH3Br flux is also sensitive to variations in the rate of CH3Br production. We have quantified these effects using a simple steady state mass balance model. When CH3Br production rates are linearly scaled with seawater chlorophyll content, this model reproduces the latitudinal variations in marine CH3Br concentrations observed in the east Pacific Ocean by Singh et al. [1983] and by Lobert et al. [1995]. The apparent correlation of CH3Br production with primary production explains the discrepancies between the two observational studies, strengthening recent suggestions that the open ocean is a small net sink for atmospheric CH3Br, rather than a large net source. The Southern Ocean is implicated as a possible large net source of CH3Br to the atmosphere. Since our model indicates that both the direction and magnitude of CH3Br exchange between the atmosphere and ocean are extremely sensitive to temperature and marine productivity, and since the rate of CH3Br production in the oceans is comparable to the rate at which this compound is introduced to the atmosphere, even small

Methyl bromide: ocean sources, ocean sinks, and climate sensitivity.

PubMed

Anbar, A D; Yung, Y L; Chavez, F P

1996-03-01

The oceans play an important role in the geochemical cycle of methyl bromide (CH3Br), the major carrier of O3-destroying bromine to the stratosphere. The quantity of CH3Br produced annually in seawater is comparable to the amount entering the atmosphere each year from natural and anthropogenic sources. The production mechanism is unknown but may be biological. Most of this CH3Br is consumed in situ by hydrolysis or reaction with chloride. The size of the fraction which escapes to the atmosphere is poorly constrained; measurements in seawater and the atmosphere have been used to justify both a large oceanic CH3Br flux to the atmosphere and a small net ocean sink. Since the consumption reactions are extremely temperature-sensitive, small temperature variations have large effects on the CH3Br concentration in seawater, and therefore on the exchange between the atmosphere and the ocean. The net CH3Br flux is also sensitive to variations in the rate of CH3Br production. We have quantified these effects using a simple steady state mass balance model. When CH3Br production rates are linearly scaled with seawater chlorophyll content, this model reproduces the latitudinal variations in marine CH3Br concentrations observed in the east Pacific Ocean by Singh et al. [1983] and by Lobert et al. [1995]. The apparent correlation of CH3Br production with primary production explains the discrepancies between the two observational studies, strengthening recent suggestions that the open ocean is a small net sink for atmospheric CH3Br, rather than a large net source. The Southern Ocean is implicated as a possible large net source of CH3Br to the atmosphere. Since our model indicates that both the direction and magnitude of CH3Br exchange between the atmosphere and ocean are extremely sensitive to temperature and marine productivity, and since the rate of CH3Br production in the oceans is comparable to the rate at which this compound is introduced to the atmosphere, even small

40 CFR 227.14 - Criteria for evaluating the need for ocean dumping and alternatives to ocean dumping.

Code of Federal Regulations, 2013 CFR

2013-07-01

... ocean dumping and alternatives to ocean dumping. 227.14 Section 227.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Need for Ocean Dumping § 227.14 Criteria for evaluating the need for ocean...

40 CFR 227.14 - Criteria for evaluating the need for ocean dumping and alternatives to ocean dumping.

Code of Federal Regulations, 2010 CFR

2010-07-01

... ocean dumping and alternatives to ocean dumping. 227.14 Section 227.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Need for Ocean Dumping § 227.14 Criteria for evaluating the need for ocean...

40 CFR 227.14 - Criteria for evaluating the need for ocean dumping and alternatives to ocean dumping.

Code of Federal Regulations, 2011 CFR

2011-07-01

... ocean dumping and alternatives to ocean dumping. 227.14 Section 227.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Need for Ocean Dumping § 227.14 Criteria for evaluating the need for ocean...

40 CFR 227.14 - Criteria for evaluating the need for ocean dumping and alternatives to ocean dumping.

Code of Federal Regulations, 2014 CFR

2014-07-01

... ocean dumping and alternatives to ocean dumping. 227.14 Section 227.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Need for Ocean Dumping § 227.14 Criteria for evaluating the need for ocean...

40 CFR 227.14 - Criteria for evaluating the need for ocean dumping and alternatives to ocean dumping.

Code of Federal Regulations, 2012 CFR

2012-07-01

... ocean dumping and alternatives to ocean dumping. 227.14 Section 227.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Need for Ocean Dumping § 227.14 Criteria for evaluating the need for ocean...

Impact of Targeted Ocean Observations for Improving Ocean Model Initialization for Coupled Hurricane Forecasting

NASA Astrophysics Data System (ADS)

Halliwell, G. R.; Srinivasan, A.; Kourafalou, V. H.; Yang, H.; Le Henaff, M.; Atlas, R. M.

2012-12-01

The accuracy of hurricane intensity forecasts produced by coupled forecast models is influenced by errors and biases in SST forecasts produced by the ocean model component and the resulting impact on the enthalpy flux from ocean to atmosphere that powers the storm. Errors and biases in fields used to initialize the ocean model seriously degrade SST forecast accuracy. One strategy for improving ocean model initialization is to design a targeted observing program using airplanes and in-situ devices such as floats and drifters so that assimilation of the additional data substantially reduces errors in the ocean analysis system that provides the initial fields. Given the complexity and expense of obtaining these additional observations, observing system design methods such as OSSEs are attractive for designing efficient observing strategies. A new fraternal-twin ocean OSSE system based on the HYbrid Coordinate Ocean Model (HYCOM) is used to assess the impact of targeted ocean profiles observed by hurricane research aircraft, and also by in-situ float and drifter deployments, on reducing errors in initial ocean fields. A 0.04-degree HYCOM simulation of the Gulf of Mexico is evaluated as the nature run by determining that important ocean circulation features such as the Loop Current and synoptic cyclones and anticyclones are realistically simulated. The data-assimilation system is run on a 0.08-degree HYCOM mesh with substantially different model configuration than the nature run, and it uses a new ENsemble Kalman Filter (ENKF) algorithm optimized for the ocean model's hybrid vertical coordinates. The OSSE system is evaluated and calibrated by first running Observing System Experiments (OSEs) to evaluate existing observing systems, specifically quantifying the impact of assimilating more than one satellite altimeter, and also the impact of assimilating targeted ocean profiles taken by the NOAA WP-3D hurricane research aircraft in the Gulf of Mexico during the Deepwater

Functional integrity of the interrenal tissue of yellow perch from contaminated sites tested in vivo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Girard, C.; Brodeur, J.C.; Hontela, A.

1995-12-31

The normal activation of the hypothalamo-pituitary-interrenal axis (HPI axis) in response to capture is disrupted in fish subjected to life-long exposure to heavy metals, PCBs and PAHs. The ability to increase plasma cortisol in yellow perch (Perca flavescens) from sites contaminated by heavy metals and organic compounds, and from a reference site was assessed by the Capture stress test and by the ACTH Challenge test, a new standardized in vivo method designed for field studies. The effects of seasonal factors, such as temperature and gonadal maturity on these tests were investigated. Measures of liver and muscle glycogen and histopathology weremore » made to further characterize the biochemical and structural changes that may occur along with hormonal changes. The Capture stress test showed that an acute source of stress induced a lower cortisol response in fish from the highly contaminated site compared to the reference site, revealing a functional impairment of the HPI axis. The ACTH Challenge test showed that the hormonal responsiveness of the cortisol-secreting interrenal tissue, stimulated by a standard dose of ACTH injected i.p., was lower in fish from the highly contaminated site than the reference site. Spring is the season during which the impairment was the most evident. The possibility of using the reduced capacity of feral fish to respond to a standardized ACTH Challenge as an early bioindicator of toxic stress is discussed.« less

Does overwinter temperature affect maternal body composition and egg traits in yellow perch Perca flavescens?

PubMed

Feiner, Z S; Coulter, D P; Guffey, S C; Höök, T O

2016-04-01

Female yellow perch Perca flavescens exposed to three overwinter temperature regimes (4, 8 and 13° C) for 150 days spawned in markedly different proportions upon spring warming (37% of females in 4° C v. 64 and 91% in 8 and 13° C treatments, respectively), but exhibited no differences in fecundity, egg size or egg lipid content. Females held at 4° C also exhibited less within-clutch egg size variation than females held at 13° C. Moreover, eggs differed among temperature treatments in the overall proportions of 18 fatty acids, with the colder treatments resulting in potentially higher quality eggs containing more of the unsaturated fatty acids C16:1, C22:6-n3 and C18:2 cis. Female somatic condition also varied with temperature. Maternal somatic growth and protein content increased while lipid content decreased in 13° C compared to the colder treatments. There were, however, no differences among treatments in the fatty acid composition of maternal muscle. These results suggest that the temperatures experienced during winter may be less influential to P. flavescens egg size or number, which may exhibit relatively little plasticity in this species, but can alter both the number of females that spawn and the overall composition of eggs and maternal somatic tissues, which may have implications for future reproductive success. © 2016 The Fisheries Society of the British Isles.

Mesoscale Atmosphere-Ocean Coupling Enhances the Transfer of Wind Energy into the Ocean.

NASA Astrophysics Data System (ADS)

Byrne, D.; Munnich, M.; Frenger, I.; Gruber, N.

2016-02-01

Ocean eddies receive their energy mainly from the atmospheric energy input at large scales, while it is thought that direct atmosphere-ocean interactions at this scale contribute little to the eddies' energy balance. If anything, the prevailing view is that mesoscale atmosphere-ocean interactions lead to a reduction of the energy transfer from the atmosphere to the ocean. From satellite observations, modelling studies and theory, we present results in contrast to this. Specifically, we describe a novel mechanism that provides a new energy pathway from the atmosphere into the ocean that directly injects energy at the mesoscale, shortcutting the classical main pathway from the larger scales. Our hypothesis is based upon recent evidence that the `coupling strength' i.e., the magnitude of the atmospheric response to underlying sea surface temperature anomalies associated with eddies, is dependent upon the background wind speed. We argue that ocean eddies rarely live in an area of constant background wind, particularly not in the Southern Ocean, and that the horizontal gradients in the wind across ocean eddies lead to an increased/decreased work on one side of the eddy that is not compensated for on the other. Essentially, this asymmetry provides a `spin up' or a `spin down' forcing such that the net result is an increase in kinetic energy for both warm and cold core eddies that reside in a negative wind gradient and a decrease in kinetic energy when they are located in a positive wind gradient. This result has strong implications for the Southern Ocean, where large regions of positive and negative wind gradients exist on both sides of the wind maximum. We show from diagnosing the local eddy scale and domain wide energy balance in a high-resolution coupled atmosphere-ocean regional model in the South Atlantic, there are different energy transfers in the two regions and due to the different eddy abundances that this mechanism increases the net kinetic energy contained in

Ocean transport and variability studies of the South Pacific, Southern, and Indian Oceans

NASA Technical Reports Server (NTRS)

Church, John A.; Cresswell, G. R.; Nilsson, C. S.; Mcdougall, T. J.; Coleman, R.; Rizos, C.; Penrose, J.; Hunter, J. R.; Lynch, M. J.

1991-01-01

The objectives of this study are to analyze ocean dynamics in the western South Pacific and the adjacent Southern Ocean and the eastern Indian Ocean. Specifically, our objectives for these three regions are, for the South Pacific Ocean: (1) To estimate the volume transport of the east Australian Current (EAC) along the Australian coast and in the Tasman Front, and to estimate the time variability (on seasonal and interannual time scales) of this transport. (2) To contribute to estimating the meridional heat and freshwater fluxes (and their variability) at about 30 deg S. Good estimates of the transport in the western boundary current are essential for accurate estimates of these fluxes. (3) To determine how the EAC transport (and its extension, the Tasman Front and the East Auckland Current) closes the subtropical gyre of the South Pacific and to better determine the structure at the confluence of this current and the Antarctic Circumpolar Current. (4) To examine the structure and time variability of the circulation in the western South Pacific and the adjacent Southern Ocean, particularly at the Tasman Front. For the Indian Ocean: (5) To study the seasonal interannual variations in the strength of the Leeuwin Current. (6) To monitor the Pacific-Indian Ocean throughflow and the South Equatorial and the South Java Currents between northwest Australia and Indonesia. (7) To study the processes that form the water of the permanent oceanic thermocline and, in particular, the way in which new thermocline water enters the permanent thermocline in late winter and early spring as the mixed layer restratifies. For the Southern Ocean: (8) To study the mesoscale and meridional structure of the Southern Ocean between 150 deg E and 170 deg E; in particular, to describe the Antarctic frontal system south of Tasmania and determine its interannual variability; to estimate the exchanges of heat, salt, and other properties between the Indian and Pacific Oceans; and to investigate the

Validation and Inter-comparison Against Observations of GODAE Ocean View Ocean Prediction Systems

NASA Astrophysics Data System (ADS)

Xu, J.; Davidson, F. J. M.; Smith, G. C.; Lu, Y.; Hernandez, F.; Regnier, C.; Drevillon, M.; Ryan, A.; Martin, M.; Spindler, T. D.; Brassington, G. B.; Oke, P. R.

2016-02-01

For weather forecasts, validation of forecast performance is done at the end user level as well as by the meteorological forecast centers. In the development of Ocean Prediction Capacity, the same level of care for ocean forecast performance and validation is needed. Herein we present results from a validation against observations of 6 Global Ocean Forecast Systems under the GODAE OceanView International Collaboration Network. These systems include the Global Ocean Ice Forecast System (GIOPS) developed by the Government of Canada, two systems PSY3 and PSY4 from the French Mercator-Ocean Ocean Forecasting Group, the FOAM system from UK met office, HYCOM-RTOFS from NOAA/NCEP/NWA of USA, and the Australian Bluelink-OceanMAPS system from the CSIRO, the Australian Meteorological Bureau and the Australian Navy.The observation data used in the comparison are sea surface temperature, sub-surface temperature, sub-surface salinity, sea level anomaly, and sea ice total concentration data. Results of the inter-comparison demonstrate forecast performance limits, strengths and weaknesses of each of the six systems. This work establishes validation protocols and routines by which all new prediction systems developed under the CONCEPTS Collaborative Network will be benchmarked prior to approval for operations. This includes anticipated delivery of CONCEPTS regional prediction systems over the next two years including a pan Canadian 1/12th degree resolution ice ocean prediction system and limited area 1/36th degree resolution prediction systems. The validation approach of comparing forecasts to observations at the time and location of the observation is called Class 4 metrics. It has been adopted by major international ocean prediction centers, and will be recommended to JCOMM-WMO as routine validation approach for operational oceanography worldwide.

Harnessing mtDNA variation to resolve ambiguity in ‘Redfish’ sold in Europe

PubMed Central

Moore, Lauren; Pampoulie, Christophe; Di Muri, Cristina; Vandamme, Sara; Mariani, Stefano

2017-01-01

Morphology-based identification of North Atlantic Sebastes has long been controversial and misidentification may produce misleading data, with cascading consequences that negatively affect fisheries management and seafood labelling. North Atlantic Sebastes comprises of four species, commonly known as ‘redfish’, but little is known about the number, identity and labelling accuracy of redfish species sold across Europe. We used a molecular approach to identify redfish species from ‘blind’ specimens to evaluate the performance of the Barcode of Life (BOLD) and Genbank databases, as well as carrying out a market product accuracy survey from retailers across Europe. The conventional BOLD approach proved ambiguous, and phylogenetic analysis based on mtDNA control region sequences provided a higher resolution for species identification. By sampling market products from four countries, we found the presence of two species of redfish (S. norvegicus and S. mentella) and one unidentified Pacific rockfish marketed in Europe. Furthermore, public databases revealed the existence of inaccurate reference sequences, likely stemming from species misidentification from previous studies, which currently hinders the efficacy of DNA methods for the identification of Sebastes market samples. PMID:29018597

The Paleo-ocean of Mars

NASA Technical Reports Server (NTRS)

Brandenburg, John E.

1987-01-01

A Paleo-ocean on the northern plains of Mars is proposed. The hypothetical ocean would have formed very early in Mars' history, during the early period of rapid outgassing and cratering. As the ocean froze and receded, bursting of aquifers along the shoreline would create catastrophic flooding. Analysis of soil at the two Viking landing sites, both of which occur on the floor of the hypothetical ocean, is not inconsistent with an oceanic clay rich in water soluble salts.

Redescription of the Indo-Pacific scorpionfish Scorpaenodes guamensis (Quoy & Gaimard 1824) (Scorpaenidae), a senior synonym of seven nominal species.

PubMed

Motomura, Hiroyuki; Causse, Romain; Struthers, Carl D

2016-01-21

The Indo-Pacific scorpionfish, Scorpaenodes guamensis (Quoy & Gaimard 1824), is redescribed on the basis of 137 specimens, including types, from a wide geographic range in the Indo-Pacific. Seven nominal species, Scorpaena rubropunctata Cuvier in Cuvier & Valenciennes 1829, Sebastes minutus Cuvier in Cuvier & Valenciennes 1829, Scorpaena chilioprista Rüppell 1838, Scorpaena polylepis Bleeker 1851, Centropogon echinatus Macleay 1881, Scorpaena erinacea Garman 1903, and Scorpaenopsis quiescens Seale 1906, are regarded here as junior synonyms of S. guamensis. The type status of these nominal species is discussed, and lectotypes of Scorpaena guamensis, Scorpaena rubropunctata, Sebastes minutus, and Scorpaena polylepis are herein designated. Validity of Scorpaenopsis scaber (Ramsay & Ogilby 1886) is also discussed.

Law sets up oceans commission

NASA Astrophysics Data System (ADS)

Showstack, Randy

In an anticipated move, U.S. President Bill Clinton on August 7 signed into law the Oceans Act of 2000.The bipartisan legislation, which takes effect on January 20,2001, establishes a commission on ocean policy to examine federal ocean policy and environmental and economic trends affecting oceans and coasts.The act—which grew out of a call issued by Clinton at the National Oceans Conference in Monterey, California in 1998—requires the commission to submit recommendations to Congress and the president within 18 months of its appointment, and for the President to submit proposals to Congress about the use and stewardship of ocean and coastal resources.

People and Oceans.

ERIC Educational Resources Information Center

NatureScope, 1988

1988-01-01

Discusses people's relationship with oceans, focusing on ocean pollution, use, and protective measures of the sea and its wildlife. Activities included are "Mythical Monsters"; "Globetrotters"; "Plastic in the Sea"; and "Sea of Many Uses." (RT)

Global Mapping of Oceanic and Continental Shelf Crustal Thickness and Ocean-Continent Transition Structure

NASA Astrophysics Data System (ADS)

Kusznir, Nick; Alvey, Andy; Roberts, Alan

2017-04-01

The 3D mapping of crustal thickness for continental shelves and oceanic crust, and the determination of ocean-continent transition (OCT) structure and continent-ocean boundary (COB) location, represents a substantial challenge. Geophysical inversion of satellite derived free-air gravity anomaly data incorporating a lithosphere thermal anomaly correction (Chappell & Kusznir, 2008) now provides a useful and reliable methodology for mapping crustal thickness in the marine domain. Using this we have produced the first comprehensive maps of global crustal thickness for oceanic and continental shelf regions. Maps of crustal thickness and continental lithosphere thinning factor from gravity inversion may be used to determine the distribution of oceanic lithosphere, micro-continents and oceanic plateaux including for the inaccessible polar regions (e.g. Arctic Ocean, Alvey et al.,2008). The gravity inversion method provides a prediction of continent-ocean boundary location which is independent of ocean magnetic anomaly and isochron interpretation. Using crustal thickness and continental lithosphere thinning factor maps with superimposed shaded-relief free-air gravity anomaly, we can improve the determination of pre-breakup rifted margin conjugacy and sea-floor spreading trajectory during ocean basin formation. By restoring crustal thickness & continental lithosphere thinning to their initial post-breakup configuration we show the geometry and segmentation of the rifted continental margins at their time of breakup, together with the location of highly-stretched failed breakup basins and rifted micro-continents. For detailed analysis to constrain OCT structure, margin type (i.e. magma poor, "normal" or magma rich) and COB location, a suite of quantitative analytical methods may be used which include: (i) Crustal cross-sections showing Moho depth and crustal basement thickness from gravity inversion. (ii) Residual depth anomaly (RDA) analysis which is used to investigate OCT

Emerged Oceanic Plateaux and Their Role in Regulating Archean Ocean and Atmosphere Composition

NASA Astrophysics Data System (ADS)

Kamber, B. S.

2009-05-01

A geologist associates the Earth's surface division into land and oceans instinctively with continents and oceanic plates. Here I propose that for the Archean eon, we need to break with this concept. As an alternative I propose a three-fold division. Continental land, relatively thin oceanic plates covered by water and also much thicker oceanic plateaux that were at least episodically emerged and contributed ca. 50% of the total land mass. The rationale for this proposal is a long-standing conundrum locked up in ancient hydrogenous sediments precipitated from seawater. They contain elemental and isotopic records with mutually exclusive conclusions regarding the supply of elements. Namely, isotopic data, particularly Sr, are interpreted to imply a preponderance of hydrothermal flux to the ocean. The elemental abundance of Eu, however, apparently requires a much greater flux from land. Yet a higher flux from continental land mass would be visible in the Sr- isotope record. I will present additional evidence from the origin of the marine rare earth element (REE) pattern that deepens the conundrum, which can be solved if the Archean landmass included emerged oceanic plateaux in addition to the continents. The appeal of the idea is that the marine REE inventory, including Eu, is only influenced by relative fluxes from hydrothermal vents and land, regardless of the nature of the land. Strontium isotopes, on the other hand, cannot discriminate between hydrothermal flux and riverine input draining juvenile oceanic plateaux. Using this concept, I will present a simple quantitative model that explains the evidence with a landmass at the end of the Archean that was comparable in area to that of today but made up to ca. 60% by oceanic plateaux. My proposal has implications far beyond the REE and Sr fluxes to the ocean. In particular, it requires the Archean upper mantle to have been relatively cool, potentially allowing for subduction of the thin oceanic lithosphere along

Ocean Drilling Simulation Activity.

ERIC Educational Resources Information Center

Telese, James A.; Jordan, Kathy

The Ocean Drilling Project brings together scientists and governments from 20 countries to explore the earth's structure and history as it is revealed beneath the oceans' basins. Scientific expeditions examine rock and sediment cores obtained from the ocean floor to learn about the earth's basic processes. The series of activities in this…

Mission to Planet Earth. The living ocean: Observing ocean color from space

NASA Technical Reports Server (NTRS)

1994-01-01

Measurements of ocean color are part of NASA's Mission to Planet Earth, which will assess how the global environment is changing. Using the unique perspective available from space, NASA will observe, monitor, and study large-scale environmental processes, focusing on quantifying climate change. NASA will distribute the results of these studies to researchers worldwide to furnish a basis for informed decisions on environmental protection and economic policy. This information packet includes discussion on the reasons for measuring ocean color, the carbon cycle and ocean color, priorities for global climate research, and SeWiFS (sea-viewing wide field-of-view sensor) global ocean color measurements.

Ocean FEST and TECH: Inspiring Hawaii's Students to Pursue Ocean, Earth and Environmental Science Careers

NASA Astrophysics Data System (ADS)

Bruno, B. C.; Wren, J. L.; Ayau, J. F.

2013-12-01

Ocean TECH (Technology Expands Career Horizons) is a new initiative funded by NSF/GeoEd to stimulate interest in ocean, earth and environmental science careers - and the college majors that lead to such careers - among Hawaii's underrepresented students in grades 6-14. The Ocean TECH project features hands-on ocean science and technology and interactions with career professionals. Ocean TECH builds upon Ocean FEST (Families Exploring Science Together), a previous NSF/OEDG project aimed at teaching fun hands-on science in culturally and locally relevant ways to Hawaii's elementary school students and their families. Ocean FEST was rigorously evaluated (including cognitive pre-testing developed in partnership with external evaluators) and shown to be successful both in teaching science content and changing attitudes toward ocean, earth and environmental science careers. Over the course of the four-year grant, Ocean FEST reached 20,99 students and adults, including 636 classroom teachers and other volunteers who assisted with program delivery, most of whom were from underrepresented groups. For more info on Ocean FEST: http://oceanfest.soest.hawaii.edu/ Ocean TECH events have various formats, but common themes include: (1) Using technology as a hook to engage students in ocean, earth and environmental science. (2) Bringing middle school through community college students to college campuses, where they engage in hands-on science activities and learn about college majors. (3) Drawing direct links between the students' hands-on science activities and the research currently occurring at the UH Manoa's School of Ocean and Earth Science and Technology (SOEST), such as C-MORE and HOT research. (4) Respecting and valuing students' local knowledge and experiences. (5) Explicitly showing, through concrete examples, how becoming an ocean, earth or environmental scientist addresses would beneit Hawaii (6) Having graduate students from diverse backgrounds serve as instructors and

The Global Ocean Observing System

NASA Technical Reports Server (NTRS)

Kester, Dana

1992-01-01

A Global Ocean Observing System (GOOS) should be established now with international coordination (1) to address issues of global change, (2) to implement operational ENSO forecasts, (3) to provide the data required to apply global ocean circulation models, and (4) to extract the greatest value from the one billion dollar investment over the next ten years in ocean remote sensing by the world's space agencies. The objectives of GOOS will focus on climatic and oceanic predictions, on assessing coastal pollution, and in determining the sustainability of living marine resources and ecosystems. GOOS will be a complete system including satellite observations, in situ observations, numerical modeling of ocean processes, and data exchange and management. A series of practical and economic benefits will be derived from the information generated by GOOS. In addition to the marine science community, these benefits will be realized by the energy industries of the world, and by the world's fisheries. The basic oceanic variables that are required to meet the oceanic and predictability objectives of GOOS include wind velocity over the ocean, sea surface temperature and salinity, oceanic profiles of temperature and salinity, surface current, sea level, the extent and thickness of sea ice, the partial pressure of CO2 in surface waters, and the chlorophyll concentration of surface waters. Ocean circulation models and coupled ocean-atmosphere models can be used to evaluate observing system design, to assimilate diverse data sets from in situ and remotely sensed observations, and ultimately to predict future states of the system. The volume of ocean data will increase enormously over the next decade as new satellite systems are launched and as complementary in situ measuring systems are deployed. These data must be transmitted, quality controlled, exchanged, analyzed, and archived with the best state-of-the-art computational methods.

Dust and Ocean Plants

NASA Technical Reports Server (NTRS)

2002-01-01

Adding iron to the diet of marine plant life has been shown in shipboard experiments to boost the amount of carbon-absorbing phytoplankton in certain parts of the world's oceans. A new study promises to give scientists their first global picture of the extent of these unique 'iron-limited' ocean regions, an important step in understanding how the ocean's biology controls the flow of carbon between the atmosphere and the ocean. The new study by researchers at NASA's Goddard Space Flight Center and the Department of Energy's Oak Ridge National Laboratory was presented at the American Geophysical Union's annual meeting in San Francisco on Friday, Dec. 15, 2000. Oceanic phytoplankton remove nearly as much carbon from the atmosphere each year as all land-based plants. Identifying the location and size of nutrient-limited areas in the open ocean has challenged oceanographers for nearly a century. The study pinpointed iron-limited regions by seeing which phytoplankton-rich areas of the world's oceans were also areas that received iron from wind-blown dust. In this map, areas with high levels of chlorophyll from phytoplankton and high levels of dust deposition (high correlation coefficients) are indicated in dark brown. Dust deposition was calculated by a 3-year modelled climatology for the years 1996-1998. The chlorophyll measurements are from 1998 observations from the SeaWiFS (Sea-viewing Wide Field-of-view Sensor) instrument on the OrbView-2 satellite. 'Global, satellite-based analyses such as this gives us insight into where iron deposition may be limiting ocean biological activity,' says lead author David Erickson of Oak Ridge National Laboratory's Computer Science and Mathematics Division. 'With this information we will be able to infer how the ocean productivity/iron deposition relationship might shift in response to climate change.' Map Source: David Erickson, Oak Ridge National Laboratory's Computer Science and Mathematics Division

A window on the deep ocean: The special value of ocean bottom pressure for monitoring the large-scale, deep-ocean circulation

NASA Astrophysics Data System (ADS)

Hughes, Chris W.; Williams, Joanne; Blaker, Adam; Coward, Andrew; Stepanov, Vladimir

2018-02-01

We show how, by focusing on bottom pressure measurements particularly on the global continental slope, it is possible to avoid the "fog" of mesoscale variability which dominates most observables in the deep ocean. This makes it possible to monitor those aspects of the ocean circulation which are most important for global scale ocean variability and climate. We therefore argue that such measurements should be considered an important future component of the Global Ocean Observing System, to complement the present open-ocean and coastal elements. Our conclusions are founded on both theoretical arguments, and diagnostics from a fine-resolution ocean model that has realistic amplitudes and spectra of mesoscale variability. These show that boundary pressure variations are coherent over along-slope distances of tens of thousands of kilometres, for several vertical modes. We illustrate the value of this in the model Atlantic, by determining the time for boundary and equatorial waves to complete a circuit of the northern basin (115 and 205 days for the first and second vertical modes), showing how the boundary features compare with basin-scale theoretical models, and demonstrating the ability to monitor the meridional overturning circulation using these boundary measurements. Finally, we discuss applicability to the real ocean and make recommendations on how to make such measurements without contamination from instrumental drift.

The Ocean: Our Future

NASA Astrophysics Data System (ADS)

Independent World Commission On The Oceans; Soares, Mario

1998-09-01

The Ocean, Our Future is the official report of the Independent World Commission on the Oceans, chaired by Mário Soares, former President of Portugal. Its aim is to summarize the very real problems affecting the ocean and its future management, and to provide imaginative solutions to these various and interlocking problems. The oceans have traditionally been taken for granted as a source of wealth, opportunity and abundance. Our growing understanding of the oceans has fundamentally changed this perception. We now know that in some areas, abundance is giving way to real scarcity, resulting in severe conflicts. Territorial disputes that threaten peace and security, disruptions to global climate, overfishing, habitat destruction, species extinction, indiscriminate trawling, pollution, the dumping of hazardous and toxic wastes, piracy, terrorism, illegal trafficking and the destruction of coastal communities are among the problems that today form an integral part of the unfolding drama of the oceans. Based on the deliberations, experience and input of more than 100 specialists from around the world, this timely volume provides a powerful overview of the state of our water world.

Ocean heat content variability and change in an ensemble of ocean reanalyses

NASA Astrophysics Data System (ADS)

Palmer, M. D.; Roberts, C. D.; Balmaseda, M.; Chang, Y.-S.; Chepurin, G.; Ferry, N.; Fujii, Y.; Good, S. A.; Guinehut, S.; Haines, K.; Hernandez, F.; Köhl, A.; Lee, T.; Martin, M. J.; Masina, S.; Masuda, S.; Peterson, K. A.; Storto, A.; Toyoda, T.; Valdivieso, M.; Vernieres, G.; Wang, O.; Xue, Y.

2017-08-01

Accurate knowledge of the location and magnitude of ocean heat content (OHC) variability and change is essential for understanding the processes that govern decadal variations in surface temperature, quantifying changes in the planetary energy budget, and developing constraints on the transient climate response to external forcings. We present an overview of the temporal and spatial characteristics of OHC variability and change as represented by an ensemble of dynamical and statistical ocean reanalyses (ORAs). Spatial maps of the 0-300 m layer show large regions of the Pacific and Indian Oceans where the interannual variability of the ensemble mean exceeds ensemble spread, indicating that OHC variations are well-constrained by the available observations over the period 1993-2009. At deeper levels, the ORAs are less well-constrained by observations with the largest differences across the ensemble mostly associated with areas of high eddy kinetic energy, such as the Southern Ocean and boundary current regions. Spatial patterns of OHC change for the period 1997-2009 show good agreement in the upper 300 m and are characterized by a strong dipole pattern in the Pacific Ocean. There is less agreement in the patterns of change at deeper levels, potentially linked to differences in the representation of ocean dynamics, such as water mass formation processes. However, the Atlantic and Southern Oceans are regions in which many ORAs show widespread warming below 700 m over the period 1997-2009. Annual time series of global and hemispheric OHC change for 0-700 m show the largest spread for the data sparse Southern Hemisphere and a number of ORAs seem to be subject to large initialization `shock' over the first few years. In agreement with previous studies, a number of ORAs exhibit enhanced ocean heat uptake below 300 and 700 m during the mid-1990s or early 2000s. The ORA ensemble mean (±1 standard deviation) of rolling 5-year trends in full-depth OHC shows a relatively steady

Indian-Southern Ocean Latitudinal Transect (ISOLAT): A proposal for the recovery of high-resolution sedimentary records in the western Indian Ocean sector of the Southern Ocean

NASA Astrophysics Data System (ADS)

Mackensen, A.; Zahn, R.; Hall, I.; Kuhn, G.; Koc, N.; Francois, R.; Hemming, S.; Goldstein, S.; Rogers, J.; Ehrmann, W.

2003-04-01

Quantifying oceanic variability at timescales of oceanic, atmospheric, and cryospheric processes are the fundamental objectives of the international IMAGES program. In this context the Southern Ocean plays a leading role in that it is involved, through its influence on global ocean circulation and carbon budget, with the development and maintenance of the Earth's climate system. The seas surrounding Antarctica contain the world's only zonal circum-global current system that entrains water masses from the three main ocean basins, and maintains the thermal isolation of Antarctica from warmer surface waters to the north. Furthermore, the Southern Ocean is a major site of bottom and intermediate water formation and thus actively impacts the global thermohaline circulation (THC). This proposal is an outcome of the IMAGES Southern Ocean Working Group and constitutes one component of a suite of new IMAGES/IODP initiatives that aim at resolving past variability of the Antarctic Circumpolar Current (ACC) on orbital and sub-orbital timescales and its involvement with rapid global ocean variability and climate instability. The primary aim of this proposal is to determine millennial- to sub-centennial scale variability of the ACC and the ensuing Atlantic-Indian water transports, including surface transports and deep-water flow. We will focus on periods of rapid ocean and climate change and assess the role of the Southern Ocean in these changes, both in terms of its thermohaline circulation and biogeochemical inventories. We propose a suite of 11 sites that form a latitudinal transect across the ACC in the westernmost Indian Ocean sector of the Southern Ocean. The transect is designed to allow the reconstruction of ACC variability across a range of latitudes in conjunction with meridional shifts of the surface ocean fronts. The northernmost reaches of the transect extend into the Agulhas Current and its retroflection system which is a key component of the THC warm water return

Deep Water Ocean Acoustics

DTIC Science & Technology

2016-08-03

Militia Drive Lexington, MA 02421 Date Submitted: Aug 3, 2016 Notices : Distribution Statement A. Approved for public release...distribution is unlimited. OASIS, INC. 2 Report No. QSR-14C0172-Ocean Acoustics-063016 Contents Notices ...the impact of the ocean and seafloor environmental variability on deep-water (long-range) ocean acoustic propagation and to develop methodologies

The Coastal Ocean Prediction Systems program: Understanding and managing our coastal ocean

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eden, H.F.; Mooers, C.N.K.

1990-06-01

The goal of COPS is to couple a program of regular observations to numerical models, through techniques of data assimilation, in order to provide a predictive capability for the US coastal ocean including the Great Lakes, estuaries, and the entire Exclusive Economic Zone (EEZ). The objectives of the program include: determining the predictability of the coastal ocean and the processes that govern the predictability; developing efficient prediction systems for the coastal ocean based on the assimilation of real-time observations into numerical models; and coupling the predictive systems for the physical behavior of the coastal ocean to predictive systems for biological,more » chemical, and geological processes to achieve an interdisciplinary capability. COPS will provide the basis for effective monitoring and prediction of coastal ocean conditions by optimizing the use of increased scientific understanding, improved observations, advanced computer models, and computer graphics to make the best possible estimates of sea level, currents, temperatures, salinities, and other properties of entire coastal regions.« less

Radiative transfer in the earth's atmosphere and ocean: influence of ocean waves.

PubMed

Plass, G N; Kattawar, G W; Guinn, J A

1975-08-01

The radiance in the earth's atmosphere and ocean is calculated for a realistic model including an ocean surface with waves. Individual photons are followed in a Monte Carlo calculation. In the atmosphere, both Rayleigh scattering by the molecules and Mie scattering by the aerosols as well as molecular and aerosol absorption are taken into account. Similarly, in the ocean, both Rayleigh scattering by the water molecules and Mie scattering by the hydrosols as well as absorption by the water molecules and hydrosols are considered. Separate single-scattering functions are used which are calculated separately for the aerosols and the hydrosols from the Mie theory with appropriate and different size distributions in each case. The scattering angles are determined from the appropriate scattering function including the strong forwardscattering peak when there is aerosol or hydrosol scattering. Both the reflected and refracted rays, as well as the rays that undergo total internal reflection, are followed at the oceanc surface. The wave slope is chosen from the Cox-Munk distribution. Graphs show the influence of the waves on the upward radiance at the top of the atmosphere and just above the ocean surface and on the downward radiance just below the ocean surface as well as deeper within the ocean. The radiance changes are sufficient at the top of the atmosphere to determine the sea state from satellite measurements. Within the ocean the waves smooth out the abrupt transition that occurs at the edge of the allowed cone for radiation entering a calm ocean. The influence of the waves on the contrast between the sky and sea at the horizon is discussed. It is shown that the downward flux just below the surface increases with wind speed at all solar angles.

World Ocean Circulation Experiment

NASA Technical Reports Server (NTRS)

Clarke, R. Allyn

1992-01-01

The oceans are an equal partner with the atmosphere in the global climate system. The World Ocean Circulation Experiment is presently being implemented to improve ocean models that are useful for climate prediction both by encouraging more model development but more importantly by providing quality data sets that can be used to force or to validate such models. WOCE is the first oceanographic experiment that plans to generate and to use multiparameter global ocean data sets. In order for WOCE to succeed, oceanographers must establish and learn to use more effective methods of assembling, quality controlling, manipulating and distributing oceanographic data.

Vertical Redistribution of Ocean Salt Content

NASA Astrophysics Data System (ADS)

Liang, X.; Liu, C.; Ponte, R. M.; Piecuch, C. G.

2017-12-01

Ocean salinity is an important proxy for change and variability in the global water cycle. Multi-decadal trends have been observed in both surface and subsurface salinity in the past decades, and are usually attributed to the change in air-sea freshwater flux. Although air-sea freshwater flux, a major component of the global water cycle, certainly contributes to the change in surface and upper ocean salinity, the salt redistribution inside the ocean can affect the surface and upper ocean salinity as well. Also, the mechanisms controlling the surface and upper ocean salinity changes likely depend on timescales. Here we examined the ocean salinity changes as well as the contribution of the vertical redistribution of salt with a 20-year dynamically consistent and data-constrained ocean state estimate (ECCO: Estimating Circulation and Climate of the Ocean). A decrease in the spatial mean upper ocean salinity and an upward salt flux inside the ocean were observed. These findings indicate that over 1992-2011, surface freshwater fluxes contribute to the decrease in spatial mean upper ocean salinity and are partly compensated by the vertical redistribution of salt inside the ocean. Between advection and diffusion, the two major processes determining the vertical exchange of salt, the advective term at different depths shows a downward transport, while the diffusive term is the dominant upward transport contributor. These results suggest that the salt transport in the ocean interior should be considered in interpreting the observed surface and upper ocean salinity changes, as well as inferring information about the changes in the global water cycle.

Obama Administration Announces Ocean Policy

NASA Astrophysics Data System (ADS)

Showstack, Randy

2010-08-01

With the U.S. Interagency Ocean Policy Task Force final report in hand, U.S. president Barack Obama issued an executive order on 19 July largely adopting its recommendations. These include establishing a National Policy for the Stewardship of the Ocean, Coasts, and Great Lakes; creating a National Ocean Council, which will hold its first meeting later this summer; strengthening the ocean governance structure; and providing for the development of coastal and marine spatial plans. The task force report indicates that U.S. ocean policy includes protecting, maintaining, and restoring ocean, coastal, and Great Lakes ecosystems and resources; increasing scientific understanding and using the best available science and knowledge to inform decisions about them; and improving the understanding and awareness of changing environmental conditions.

'Micro-hole' optical dating of quartz from HOTRAX-05 Arctic Ocean cores

NASA Astrophysics Data System (ADS)

Berger, G. W.; Polyak, L. V.

2011-12-01

For Quaternary Arctic Ocean cores, numeric dating methods are needed spanning and exceeding the age range of the widely used radiocarbon (C-14) method. Previously, luminescence sediment dating of 4-11 μm diameter quartz and feldspar grains from core tops has often produced large burial-age overestimates (e.g., by >7 kyr) due to failure to resolve mixed-age histories. However, application of micro-focused-laser ('micro-hole') photon-stimulated-luminescence (PSL) applied to quartz grains of 11-90 μm diameters from the tops (upper 2 cm) of high-sedimentation- rate HOTRAX-05 multi-cores at the Alaska margin provides expected near zero ages (0-200 a), thus overcoming the earlier problem of large PSL age over-estimation. This micro-hole PSL dating approach has also been applied to >11 μm quartz grains from multi-cores at two sites on the central Lomonosov Ridge. For a core top within a perched basin, a burial-age estimate of ~2 ka for 11-62 μm quartz was obtained, in accord with published C-14 age estimates from foraminifera, demonstrating the efficacy of the micro-hole approach to this ridge area. At a nearby 'erosive' ridge-top site, the micro-hole PSL approach paradoxically produces two different burial-age estimates from the same core-top horizon. The >90 μm quartz grains yield a burial age of ~25 ka, in accord with a C-14 age estimate of ~26 ka from >250 μm foraminifers from the same horizon. However, the 11-90 μm quartz produces a burial-age estimate of ~9 ka, indicating a differently preserved burial history for the medium silt grains than for the sand grains within a single horizon. This unexpected result provides a unique insight into past, complicated, depositional processes on this ridge top over a time range spanning the LGM. These results from the micro-hole PSL approach thus indicate a clear potential for dating times of detrital quartz deposition at other ridge tops in the Arctic Ocean, and for providing perhaps new insights into local preservation

Contrasting Indian Ocean SST Variability With and Without ENSO Influence: A Coupled Atmosphere-Ocean GCM Study

NASA Technical Reports Server (NTRS)

Yu, Jin-Yi; Lau, K. M.

2004-01-01

In this study, we perform experiments with a coupled atmosphere-ocean general circulation model (CGCM) to examine ENSO's influence on the interannual sea surface temperature (SST) variability of the tropical Indian Ocean. The control experiment includes both the Indian and Pacific Oceans in the ocean model component of the CGCM (the Indo-Pacific Run). The anomaly experiment excludes ENSOs influence by including only the Indian Ocean while prescribing monthly-varying climatological SSTs for the Pacific Ocean (the Indian-Ocean Run). In the Indo-Pacific Run, an oscillatory mode of the Indian Ocean SST variability is identified by a multi-channel singular spectral analysis (MSSA). The oscillatory mode comprises two patterns that can be identified with the Indian Ocean Zonal Mode (IOZM) and a basin-wide warming/cooling mode respectively. In the model, the IOZM peaks about 3-5 months after ENSO reaches its maximum intensity. The basin mode peaks 8 months after the IOZM. The timing and associated SST patterns suggests that the IOZM is related to ENSO, and the basin- wide warming/cooling develops as a result of the decay of the IOZM spreading SST anomalies from western Indian Ocean to the eastern Indian Ocean. In contrast, in the Indian-Ocean Run, no oscillatory modes can be identified by the MSSA, even though the Indian Ocean SST variability is characterized by east-west SST contrast patterns similar to the IOZM. In both control and anomaly runs, IOZM-like SST variability appears to be associated with forcings from fluctuations of the Indian monsoon. Our modeling results suggest that the oscillatory feature of the IOZM is primarily forced by ENSO.

Standardized Interpretation of Chest Radiographs in Cases of Pediatric Pneumonia From the PERCH Study.

PubMed

Fancourt, Nicholas; Deloria Knoll, Maria; Barger-Kamate, Breanna; de Campo, John; de Campo, Margaret; Diallo, Mahamadou; Ebruke, Bernard E; Feikin, Daniel R; Gleeson, Fergus; Gong, Wenfeng; Hammitt, Laura L; Izadnegahdar, Rasa; Kruatrachue, Anchalee; Madhi, Shabir A; Manduku, Veronica; Matin, Fariha Bushra; Mahomed, Nasreen; Moore, David P; Mwenechanya, Musaku; Nahar, Kamrun; Oluwalana, Claire; Ominde, Micah Silaba; Prosperi, Christine; Sande, Joyce; Suntarattiwong, Piyarat; O'Brien, Katherine L

2017-06-15

Chest radiographs (CXRs) are a valuable diagnostic tool in epidemiologic studies of pneumonia. The World Health Organization (WHO) methodology for the interpretation of pediatric CXRs has not been evaluated beyond its intended application as an endpoint measure for bacterial vaccine trials. The Pneumonia Etiology Research for Child Health (PERCH) study enrolled children aged 1-59 months hospitalized with WHO-defined severe and very severe pneumonia from 7 low- and middle-income countries. An interpretation process categorized each CXR into 1 of 5 conclusions: consolidation, other infiltrate, both consolidation and other infiltrate, normal, or uninterpretable. Two members of a 14-person reading panel, who had undertaken training and standardization in CXR interpretation, interpreted each CXR. Two members of an arbitration panel provided additional independent reviews of CXRs with discordant interpretations at the primary reading, blinded to previous reports. Further discordance was resolved with consensus discussion. A total of 4172 CXRs were obtained from 4232 cases. Observed agreement for detecting consolidation (with or without other infiltrate) between primary readers was 78% (κ = 0.50) and between arbitrators was 84% (κ = 0.61); agreement for primary readers and arbitrators across 5 conclusion categories was 43.5% (κ = 0.25) and 48.5% (κ = 0.32), respectively. Disagreement was most frequent between conclusions of other infiltrate and normal for both the reading panel and the arbitration panel (32% and 30% of discordant CXRs, respectively). Agreement was similar to that of previous evaluations using the WHO methodology for detecting consolidation, but poor for other infiltrates despite attempts at a rigorous standardization process. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Ocean deoxygenation, the global phosphorus cycle and the possibility of human-caused large-scale ocean anoxia

NASA Astrophysics Data System (ADS)

Watson, Andrew J.; Lenton, Timothy M.; Mills, Benjamin J. W.

2017-08-01

The major biogeochemical cycles that keep the present-day Earth habitable are linked by a network of feedbacks, which has led to a broadly stable chemical composition of the oceans and atmosphere over hundreds of millions of years. This includes the processes that control both the atmospheric and oceanic concentrations of oxygen. However, one notable exception to the generally well-behaved dynamics of this system is the propensity for episodes of ocean anoxia to occur and to persist for 105-106 years, these ocean anoxic events (OAEs) being particularly associated with warm `greenhouse' climates. A powerful mechanism responsible for past OAEs was an increase in phosphorus supply to the oceans, leading to higher ocean productivity and oxygen demand in subsurface water. This can be amplified by positive feedbacks on the nutrient content of the ocean, with low oxygen promoting further release of phosphorus from ocean sediments, leading to a potentially self-sustaining condition of deoxygenation. We use a simple model for phosphorus in the ocean to explore this feedback, and to evaluate the potential for humans to bring on global-scale anoxia by enhancing P supply to the oceans. While this is not an immediate global change concern, it is a future possibility on millennial and longer time scales, when considering both phosphate rock mining and increased chemical weathering due to climate change. Ocean deoxygenation, once begun, may be self-sustaining and eventually could result in long-lasting and unpleasant consequences for the Earth's biosphere. This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'.

Near-Inertial and Thermal Upper Ocean Response to Atmospheric Forcing in the North Atlantic Ocean

DTIC Science & Technology

2010-06-01

meridional transport of heat (Hoskins and Valdes, 1990). Formation of North Atlantic Subtropical Mode Water is thought to take place during the...North Atlantic Ocean MIT/WHOI Joint Program in Oceanography/ Applied Ocean Science and Engineering Massachusetts Institute of Technology Woods Hole...Oceanographic Institution MITIWHOI 2010-16 Near-inertial and Thermal Upper Ocean Response to Atmospheric Forcing in the North Atlantic Ocean by

Assimilation of SeaWiFS Ocean Chlorophyll Data into a Three-Dimensional Global Ocean Model

NASA Technical Reports Server (NTRS)

Gregg, Watson W.

2005-01-01

Assimilation of satellite ocean color data is a relatively new phenomenon in ocean sciences. However, with routine observations from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), launched in late 1997, and now with new data from the Moderate Resolution Imaging Spectroradometer (MODIS) Aqua, there is increasing interest in ocean color data assimilation. Here SeaWiFS chlorophyll data were assimilated with an established thre-dimentional global ocean model. The assimilation improved estimates of hlorophyll and primary production relative to a free-run (no assimilation) model. This represents the first attempt at ocean color data assimilation using NASA satellites in a global model. The results suggest the potential of assimilation of satellite ocean chlorophyll data for improving models.

Seeking a Role for the Ocean and Ocean Scientists in the Future of International Climate Negotiations

NASA Astrophysics Data System (ADS)

Gallo, N.; Eddebbar, Y.; Le, J. T.; Netburn, A. N.; Niles, J. O.; Sato, K.; Wilson, S.; Levin, L. A.

2016-02-01

The oceans cover 71% of the world and are essential to the climate regulation of the planet, but they are severely underrepresented in international climate negotiations. While marine ecosystems were mentioned in the preamble to the United Nations Framework Convention on Climate Change (UNFCCC), they have since been left out of the text of the Kyoto Protocol and the Paris Treaty, and ocean-focused events are lacking at UNFCCC meetings. However, marine ecosystems sustain severe impacts from climate change including warming, acidification, and deoxygenation, and these changes have economic implications for ocean-dependent nations including on tourism, fisheries sustainability, shoreline protection, and human livelihood. Ocean scientists from the Scripps Institution of Oceanography and members of Ocean Scientists for Informed Policy have partnered with the newly-formed Ocean and Climate Platform to raise ocean issues at the UNFCCC meeting in Paris through both official side event presentations within the meeting venue and offsite events for the public. This study focuses on how the role and recognition of the ocean in the UNFCCC negotiations has evolved from COP19 (2013) to COP21 (2015), what may be expected for the role of the ocean in international climate negotiations beyond the Paris Agreement, and addresses what role ocean scientists can play in this conversation.

Seeking a Role for the Ocean and Ocean Scientists in the Future of International Climate Negotiations

NASA Astrophysics Data System (ADS)

Gallo, N.; Eddebbar, Y.; Le, J. T.; Netburn, A. N.; Niles, J. O.; Sato, K.; Wilson, S.; Levin, L. A.

2016-12-01

The oceans cover 71% of the world and are essential to the climate regulation of the planet, but they are severely underrepresented in international climate negotiations. While marine ecosystems were mentioned in the preamble to the United Nations Framework Convention on Climate Change (UNFCCC), they have since been left out of the text of the Kyoto Protocol and the Paris Treaty, and ocean-focused events are lacking at UNFCCC meetings. However, marine ecosystems sustain severe impacts from climate change including warming, acidification, and deoxygenation, and these changes have economic implications for ocean-dependent nations including on tourism, fisheries sustainability, shoreline protection, and human livelihood. Ocean scientists from the Scripps Institution of Oceanography and members of Ocean Scientists for Informed Policy have partnered with the newly-formed Ocean and Climate Platform to raise ocean issues at the UNFCCC meeting in Paris through both official side event presentations within the meeting venue and offsite events for the public. This study focuses on how the role and recognition of the ocean in the UNFCCC negotiations has evolved from COP19 (2013) to COP21 (2015), what may be expected for the role of the ocean in international climate negotiations beyond the Paris Agreement, and addresses what role ocean scientists can play in this conversation.

Impact of oceanic-scale interactions on the seasonal modulation of ocean dynamics by the atmosphere.

PubMed

Sasaki, Hideharu; Klein, Patrice; Qiu, Bo; Sasai, Yoshikazu

2014-12-15

Ocean eddies (with a size of 100-300 km), ubiquitous in satellite observations, are known to represent about 80% of the total ocean kinetic energy. Recent studies have pointed out the unexpected role of smaller oceanic structures (with 1-50 km scales) in generating and sustaining these eddies. The interpretation proposed so far invokes the internal instability resulting from the large-scale interaction between upper and interior oceanic layers. Here we show, using a new high-resolution simulation of the realistic North Pacific Ocean, that ocean eddies are instead sustained by a different process that involves small-scale mixed-layer instabilities set up by large-scale atmospheric forcing in winter. This leads to a seasonal evolution of the eddy kinetic energy in a very large part of this ocean, with an amplitude varying by a factor almost equal to 2. Perspectives in terms of the impacts on climate dynamics and future satellite observational systems are briefly discussed.

Impact of oceanic-scale interactions on the seasonal modulation of ocean dynamics by the atmosphere

PubMed Central

Sasaki, Hideharu; Klein, Patrice; Qiu, Bo; Sasai, Yoshikazu

2014-01-01

Ocean eddies (with a size of 100–300 km), ubiquitous in satellite observations, are known to represent about 80% of the total ocean kinetic energy. Recent studies have pointed out the unexpected role of smaller oceanic structures (with 1–50 km scales) in generating and sustaining these eddies. The interpretation proposed so far invokes the internal instability resulting from the large-scale interaction between upper and interior oceanic layers. Here we show, using a new high-resolution simulation of the realistic North Pacific Ocean, that ocean eddies are instead sustained by a different process that involves small-scale mixed-layer instabilities set up by large-scale atmospheric forcing in winter. This leads to a seasonal evolution of the eddy kinetic energy in a very large part of this ocean, with an amplitude varying by a factor almost equal to 2. Perspectives in terms of the impacts on climate dynamics and future satellite observational systems are briefly discussed. PMID:25501039