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Sample records for lakes herring gull

  1. Investigation of spatial trends and neurochemical impacts of mercury in herring gulls across the Laurentian Great Lakes

    Energy Technology Data Exchange (ETDEWEB)

    Rutkiewicz, Jennifer [Department of Environmental Health Sciences, University of Michigan School of Public Health, 109 S. Observatory St, Ann Arbor, MI 48109 (United States); Scheuhammer, Anton; Crump, Doug; Jagla, Magdalena [Environment Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3 (Canada); Basu, Niladri, E-mail: niladri@umich.ed [Department of Environmental Health Sciences, University of Michigan School of Public Health, 109 S. Observatory St, Ann Arbor, MI 48109 (United States)

    2010-08-15

    Herring gulls (Larus argentatus) bioaccumulate mercury (Hg) but it is unknown whether they are exposed at levels of neurological concern. Here we studied brain tissues from gulls at five Great Lakes colonies and one non-Great Lakes colony during spring of 2001 and 2003. Total brain Hg concentrations ranged from 0.14 to 2.0 {mu}g/g (dry weight) with a mean of 0.54 {mu}g/g. Gulls from Scotch Bonnet Island, on the easternmost edge of the Great Lakes, had significantly higher brain Hg than other colonies. No association was found between brain Hg concentration and [3H]-ligand binding to neurochemical receptors (N-methyl-D-aspartate, muscarinic cholinergic, nicotinic cholinergic) or nicotinic receptor {alpha}-7 relative mRNA expression as previously documented in other wildlife. In conclusion, spatial trends in Hg contamination exist in herring gulls across the Great Lakes basin, and herring gulls accumulate brain Hg but not at levels associated with sub-clinical neurochemical alterations. - Spatial trends in brain mercury exist in herring gulls across the Laurentian Great Lakes though levels are not associated with neurochemical biomarkers.

  2. Investigation of spatial trends and neurochemical impacts of mercury in herring gulls across the Laurentian Great Lakes

    International Nuclear Information System (INIS)

    Rutkiewicz, Jennifer; Scheuhammer, Anton; Crump, Doug; Jagla, Magdalena; Basu, Niladri

    2010-01-01

    Herring gulls (Larus argentatus) bioaccumulate mercury (Hg) but it is unknown whether they are exposed at levels of neurological concern. Here we studied brain tissues from gulls at five Great Lakes colonies and one non-Great Lakes colony during spring of 2001 and 2003. Total brain Hg concentrations ranged from 0.14 to 2.0 μg/g (dry weight) with a mean of 0.54 μg/g. Gulls from Scotch Bonnet Island, on the easternmost edge of the Great Lakes, had significantly higher brain Hg than other colonies. No association was found between brain Hg concentration and [3H]-ligand binding to neurochemical receptors (N-methyl-D-aspartate, muscarinic cholinergic, nicotinic cholinergic) or nicotinic receptor α-7 relative mRNA expression as previously documented in other wildlife. In conclusion, spatial trends in Hg contamination exist in herring gulls across the Great Lakes basin, and herring gulls accumulate brain Hg but not at levels associated with sub-clinical neurochemical alterations. - Spatial trends in brain mercury exist in herring gulls across the Laurentian Great Lakes though levels are not associated with neurochemical biomarkers.

  3. Mercury levels in herring gulls and fish: 42 years of spatio-temporal trends in the Great Lakes.

    Science.gov (United States)

    Blukacz-Richards, E Agnes; Visha, Ariola; Graham, Matthew L; McGoldrick, Daryl L; de Solla, Shane R; Moore, David J; Arhonditsis, George B

    2017-04-01

    Total mercury levels in aquatic birds and fish communities have been monitored across the Canadian Great Lakes by Environment and Climate Change Canada (ECCC) for the past 42 years (1974-2015). These data (22 sites) were used to examine spatio-temporal variability of mercury levels in herring gull (Larus argentatus) eggs, lake trout (Salvelinus namaycush), walleye (Sander vitreus), and rainbow smelt (Osmerus mordax). Trends were quantified with dynamic linear models, which provided time-variant rates of change of mercury concentrations. Lipid content (in both fish and eggs) and length in fish were used as covariates in all models. For the first three decades, mercury levels in gull eggs and fish declined at all stations. In the 2000s, trends for herring gull eggs reversed at two sites in Lake Erie and two sites in Lake Ontario. Similar trend reversals in the 2000s were observed for lake trout in Lake Superior and at a single station in Lake Ontario. Mercury levels in lake trout continued to slowly decline at all of the remaining stations, except for Lake Huron, where the levels remained stable. A post-hoc Bayesian regression analysis suggests strong trophic interactions between herring gulls and rainbow smelt in Lake Superior and Lake Ontario, but also pinpoints the likelihood of a trophic decoupling in Lake Huron and Lake Erie. Continued monitoring of mercury levels in herring gulls and fish is required to consolidate these trophic shifts and further evaluate their broader implications. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  4. Structure of the New England herring gull population

    Science.gov (United States)

    Kadlec, J.A.; Drury, W.H.

    1968-01-01

    Measurements of the rates of population increase, reproduction, and mortality together with an observed age ratio, were used to analyze the population of the Herring Gull in New England. Data from sporadic censuses prior to this study, aerial censuses by the authors, and National Audubon Society Christmas Bird Count indicated that the New England breeding population has been doubling every 12 to 15 years since the early 1900's. This increase has involved founding new colonies and expanding the breeding range There is evidence that 15 to 30% of the adults do not breed in any given year. Sixty-one productivity measurements on 43 islands from 1963 through 1966, involving almost 13,000 nests, showed that from 0.8 to 1.4 young/breeding pair/year is the usual range of rate of production. The age distribution in the population was determined by classifying Herring Gulls by plumage category on an aerial census of the coast from Tampico, Mexico, to Cape Sable, Nova Scotia. Of the 622,000 gulls observed, 68% were adults, 17% were second- and third-year birds, and 15% were first-year birds. Mortality rates derived from band recovery data were too high to be consistent with the observed rate of population growth, productivity, and age structure. Loss of bands increasing to the rate of about 20%/year 5 years after banding eliminates most of the discrepancy. The age structure and rate of population increase indicate a mortality rate of 4 to 9% for gulls 2 years old or older, compared with the 25 to 30% indicated by band recoveries. The population structure we have developed fits everything we have observed about Herring Gull population dynamics, except mortality based on band recoveries.

  5. GPS tracking data of Lesser Black-backed Gulls and Herring Gulls breeding at the southern North Sea coast

    NARCIS (Netherlands)

    Stienen, E.W.M.; Desmet, P.; Aelterman, B.; Courtens, W.; Feys, S.; Vanermen, N.; Verstraete, H.; Van de Walle, M.; Deneudt, K.; Hernandez, F.; Houthoofdt, R.; Vanhoorne, B.; Bouten, W.; Buijs, R.-J.; Kavelaars, M.M.; Müller, W.; Herman, D.; Matheve, H.; Sotillo, A.; Lens, L.

    2016-01-01

    In this data paper, Bird tracking - GPS tracking of Lesser Black-backed Gulls and Herring Gulls breeding at the southern North Sea coast is described, a species occurrence dataset published by the Research Institute for Nature and Forest (INBO). The dataset (version 5.5) contains close to 2.5

  6. Effects of herring gulls and great black-backed gulls on breeding piping plovers, South Monomoy Island, Massachusetts. Final Report

    Science.gov (United States)

    Keane, S.E.; Fraser, J.D.; Buckley, P.A.

    2002-01-01

    The large population of breeding herring gulls and great black-backed gulls on South Monomoy Island, Cape Cod, Massachusetts has been thought to negatively affect the breeding success of the threatened piping plover. Following the Piping Plover Recovery Plan's call for gull colonies to be removed from piping plover breeding sites, in 1996, the USFWS conducted gull removal on part of South Monomoy Island. We determined relative gull abundance on South Monomoy Island from 1998-2000 by counting gulls within 100-m radius plots located on the shoreline. We quantified piping plover behavior and habitat use by conducting instantaneous and 5-minute behavioral observations. We quantified characteristics of piping plover nesting habitat by measuring characteristics along random transects. We measured gull abundance, beach width, and prey abundance, and then used logistic regression to determine what habitat characteristics influenced piping plover nesting area selection. We monitored piping plover reproductive success and population fluctuations on South Monomoy Island. Gull abundance in the gull-removal area was lower than gull abundance in the reference area throughout the piping plover breeding season. The difference in gull abundance between the areas did not affect piping plover behavior, nest success, chick survival, or productivity. We found that gull removal did not result in an increased piping plover population on the island. In both management areas, prenesting plovers preferred to forage in moist substrate habitats. Wide backshore and open vegetation habitats characterized nesting areas. Broods spent most of their time foraging and preferred moist substrate habitats when available. Plovers were not prevented from occupying more suitable habitat by large gulls. Fewer large gulls were observed near prenesting plovers, plover nests, and plover broods than near random plots. Fewer large gulls were observed in plover nesting areas than in unused areas when the nesting

  7. GPS tracking data of Lesser Black-backed Gulls and Herring Gulls breeding at the southern North Sea coast.

    Science.gov (United States)

    Stienen, Eric W M; Desmet, Peter; Aelterman, Bart; Courtens, Wouter; Feys, Simon; Vanermen, Nicolas; Verstraete, Hilbran; de Walle, Marc Van; Deneudt, Klaas; Hernandez, Francisco; Houthoofdt, Robin; Vanhoorne, Bart; Bouten, Willem; Buijs, Roland-Jan; Kavelaars, Marwa M; Müller, Wendt; Herman, David; Matheve, Hans; Sotillo, Alejandro; Lens, Luc

    2016-01-01

    In this data paper, Bird tracking - GPS tracking of Lesser Black-backed Gulls and Herring Gulls breeding at the southern North Sea coast is described, a species occurrence dataset published by the Research Institute for Nature and Forest (INBO). The dataset (version 5.5) contains close to 2.5 million occurrences, recorded by 101 GPS trackers mounted on 75 Lesser Black-backed Gulls and 26 Herring Gulls breeding at the Belgian and Dutch coast. The trackers were developed by the University of Amsterdam Bird Tracking System (UvA-BiTS, http://www.uva-bits.nl). These automatically record and transmit bird movements, which allows us and others to study their habitat use and migration behaviour in great detail. Our bird tracking network is operational since 2013. It is funded for LifeWatch by the Hercules Foundation and maintained in collaboration with UvA-BiTS and the Flanders Marine Institute (VLIZ). The recorded data are periodically released in bulk as open data (http://dataset.inbo.be/bird-tracking-gull-occurrences), and are also accessible through CartoDB and the Global Biodiversity Information Facility (GBIF).

  8. Characterization of AhR agonists reveals antagonistic activity in European herring gull (Larus argentatus) eggs.

    Science.gov (United States)

    Muusse, Martine; Christensen, Guttorm; Gomes, Tânia; Kočan, Anton; Langford, Katherine; Tollefsen, Knut Erik; Vaňková, Lenka; Thomas, Kevin V

    2015-05-01

    European herring gull (Larus argentatus) eggs from two Norwegian islands, Musvær in the south east and Reiaren in Northern Norway, were screened for dioxins, furans, and dioxin-like and selected non-dioxin-like polychlorinated biphenyls (PCBs), and subjected to non-target analysis to try to identify the aryl hydrocarbon receptor (AhR) agonists, responsible for elevated levels measured using the dioxin responsive chemically activated luciferase expression (DR-CALUX) assay. Eggs from Musvær contained chemically calculated toxic equivalent (WHO TEQ) levels of between 109 and 483 pg TEQ/g lw, and between 82 and 337 pg TEQ/g lw was determined in eggs from Reiaren. In particular PCB126 contributed highly to the total TEQ (69-82%). In 19 of the 23 samples the calculated WHO TEQ was higher than the TEQCALUX. Using CALUX specific relative effect potencies (REPs), the levels were lower at between 77 and 292 pg/g lw in eggs from Musvær and between 55 and 223 pg/g lw in eggs from Reiaren, which was higher than the TEQCALUX in 16 of the 23 samples. However, the means of the REP values and the TEQCALUX were not significantly different. This suggests the presence of compounds that can elicit antagonist effects, with a low binding affinity to the AhR. Non-target analysis identified the presence of hexachlorobenzene (HCB) (quantified at 9.6-185 pg/g lw) but neither this compound nor high concentrations of PCB126 and non-dioxin-like PCBs could explain the differences between the calculated TEQ or REP values and the TEQCALUX. Even though, for most AhR agonists, the sensitivity of herring gulls is not known, the reported levels can be considered to represent a risk for biological effects in the developing embryo, compared to LC50 values in chicken embryos. For human consumers of herring gull eggs, these eggs contain TEQ levels up to four times higher than the maximum tolerable weekly intake. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Life history of lake herring of Green Bay, Lake Michigan

    Science.gov (United States)

    Smith, Stanford H.

    1956-01-01

    Although the lake herring has been an important contributor to the commercial fish production of Green Bay, little has been known about it. This study is based on field observations and data from about 6,500 lake herring collected over the period 1948 to 1952. Relatively nonselective commercial pound nets were a primary source of material for the study of age and growth. Commercial and experimental gill nets were used to obtain data on gear selectivity and vertical distribution. Scales were employed to investigate age and growth. Age group IV normally dominated commercial catches during the first half of the calendar year and age group III the last half. At these ages the fish averaged about 10.5 inches in length. The season's growth started in May, was most rapid in July, and terminated near the end of October. The sexes grew at the same rate. Selectivity of fishing gear was found to influence the estimation of growth. Geographical and annual differences in growth are shown. Factors that might contribute to discrepancies in calculated growth are evaluated. Possible real and apparent causes of growth compensation are given. The relation between length and weight is shown to vary with sex, season, year, and method of capture. Females were relatively more plentiful in commercial catches in February than in May through December. The percentage of females decreased with increase in age in pound-net catches but increased with age in gill-net samples. Within a year class the percentage of females decreased with increase in age. Most Green Bay lake herring mature during their second or third year of life. They are pelagic spawners with most intensive spawning over shallow areas. Spawning takes place between mid-November and mid-December, and eggs hatch in April and May. Lake herring ovaries contained from 3,500 to 11,200 eggs (averaged 6,375). Progress of spawning by age, sex, and length is given. Lake herring were distributed at all depths in Green Bay in early May, were

  10. Effects of invasive European fire ants (Myrmica rubra on herring gull (Larus argentatus reproduction.

    Directory of Open Access Journals (Sweden)

    Luke E DeFisher

    Full Text Available Various invasive ant species have negatively affected reproductive success in birds by disrupting nest site selection, incubation patterns, food supply, and by direct predation on nestlings. Impacts can be particularly severe when non-native ants colonize seabird nesting islands where thousands of birds may nest in high densities on the ground or in burrows or crevices. Here we report on the first documented effects of Myrmica rubra, the European fire ant, on the reproduction of birds in its non-native range. We documented herring gulls (Larus argentatus on Appledore Island, Maine, engaging in more erratic incubation behaviors at nests infested by the ants. Newly-hatched chicks in some nests were swarmed by ants, leading to rapid chick death. Due to high overall rates of chick mortality, survival probabilities did not vary between nests with and without ant activity, however chick growth rates were slower at nests with ants than at ant-free nests. Ant infestation likely leads to longer-term fitness consequences because slower growth rates early in life may ultimately lead to lower post-fledging survival probabilities.

  11. Contaminant levels in Herring (Larus argentatus) and Great Black-backed Gull (Larus marinus) eggs from colonies in the New York harbor complex between 2012 and 2013.

    Science.gov (United States)

    Burger, Joanna; Elbin, Susan

    2015-03-01

    Birds living in coastal areas are exposed to severe storms and tidal flooding during the nesting season, but also to contaminants that move up the food chain from the water column and sediment to their prey items. We examine metals in Herring Gull (Larus argentatus) and Great Black-backed Gull (Larus marinus) eggs collected from the New York/New Jersey harbor estuary in 2012 and in 2013 to determine if there were significant yearly differences in metal levels. We test the null hypothesis that there were no significant yearly differences in metal levels. We investigate whether there were consistent differences in metals from 2012 to 2013 that might suggest a storm-related effect because Superstorm Sandy landed in New Jersey in October 2012 with high winds and extensive flooding, and view this research as exploratory. Except for arsenic, there were significant inter-year variations in the mean levels for all colonies combined for Herring Gull, and for lead, mercury and selenium for Great Black-backed Gulls. All metal levels in 2013 were less than in 2012, except for lead. These differences were present for individual colonies as well. Metal levels varied significantly among islands for Herring Gulls in both years (except for cadmium in 2013). No one colony had the highest levels of all metals for Herring Gulls. A long term data set on mercury levels in Herring Gulls indicated that the differences between 2012 and 2013 were greater than usual. Several different factors could account for these differences, and these are discussed.

  12. Amino acid specific stable nitrogen isotope values in avian tissues: Insights from captive American kestrels and wild herring gulls

    Science.gov (United States)

    Hebert, Craig E.; Popp, B.N.; Fernie, K.J.; Ka'apu-Lyons, C.; Rattner, Barnett A.; Wallsgrove, N.

    2016-01-01

    Through laboratory and field studies, the utility of amino acid compound-specific nitrogen isotope analysis (AA-CSIA) in avian studies is investigated. Captive American kestrels (Falco sparverius) were fed an isotopically characterized diet and patterns in δ15N values of amino acids (AAs) were compared to those in their tissues (muscle and red blood cells) and food. Based upon nitrogen isotope discrimination between diet and kestrel tissues, AAs could mostly be categorized as source AAs (retaining baseline δ15N values) and trophic AAs (showing 15N enrichment). Trophic discrimination factors based upon the source (phenylalanine, Phe) and trophic (glutamic acid, Glu) AAs were 4.1 (muscle) and 5.4 (red blood cells), lower than those reported for metazoan invertebrates. In a field study involving omnivorous herring gulls (Larus argentatus smithsonianus), egg AA isotopic patterns largely retained those observed in the laying female’s tissues (muscle, red blood cells, and liver). Realistic estimates of gull trophic position were obtained using bird Glu and Phe δ15N values combined with β values (difference in Glu and Phe δ15N in primary producers) for aquatic and terrestrial food webs. Egg fatty acids were used to weight β values for proportions of aquatic and terrestrial food in gull diets. This novel approach can be applied to generalist species that feed across ecosystem boundaries.

  13. Environmentally relevant organophosphate triesters in herring gulls: In vitro biotransformation and kinetics and diester metabolite formation using a hepatic microsomal assay

    International Nuclear Information System (INIS)

    Greaves, Alana K.; Su, Guanyong; Letcher, Robert J.

    2016-01-01

    The in vitro biotransformation and kinetics of six organophosphate triester (OPE) flame retardants were investigated in herring gulls (Larus argentatus) from the Great Lakes using a hepatic microsomal metabolism assay. Administration of each individual OPE (tri-n-butyl phosphate (TNBP), tris(2-butoxyethyl) phosphate (TBOEP), triphenyl phosphate (TPHP), triethyl phosphate (TEP), tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and tris(2-chloroisopropyl) phosphate (TCIPP)) to the in vitro assay (concentration range 0.01 to 10 μM) resulted in rapid depletion with the exception of TEP. Following the Michaelis-Menten enzyme kinetics model, a preliminary 2-minute incubation period was used to estimate the V max (± SE) values (i.e., the maximal rate of reaction for a saturated enzyme system), which ranged from 5.0 ± 0.4 (TPHP) to 29 ± 18 pmol/min/mg protein (TBOEP), as well as the K M (± SE) values (i.e., the OPE concentration corresponding to one half of the V max ), which ranged from 9.8 ± 1 (TPHP) to 189 ± 135 nM (TBOEP). Biotransformation assays over a 100-minute incubation period revealed that TNBP was metabolized most rapidly (with a depletion rate of 73 ± 4 pmol/min/mg protein), followed by TBOEP (53 ± 8 pmol/min/mg), TCIPP (27 ± 1 pmol/min/mg), TPHP (22 ± 2 pmol/min/mg) and TDCIPP (8 ± 1 pmol/min/mg). In vitro biotransformation of OP triesters was clearly structure-dependent where non-halogenated alkyl OP triesters were metabolized more rapidly than halogenated alkyl triesters. Halogenated OP triesters were transformed to their respective diesters more efficiently relative to non-halogenated OP triesters. To our knowledge, this is the first study to investigate OP triester metabolism and OP diester formation in an avian or wildlife model system, which is important to understand the fate and biological activity of OPEs in an exposed organism. - Highlights: • The metabolism and kinetics of 6 OPEs were examined in herring gull liver microsomes. • The

  14. Environmentally relevant organophosphate triesters in herring gulls: In vitro biotransformation and kinetics and diester metabolite formation using a hepatic microsomal assay

    Energy Technology Data Exchange (ETDEWEB)

    Greaves, Alana K. [Wildlife and Landscape Directorate, Science and Technology Branch, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3 (Canada); Department of Chemistry, Carleton University, Ottawa, ON K1S 5B6 (Canada); Su, Guanyong, E-mail: guanyong.su85@gmail.com [Wildlife and Landscape Directorate, Science and Technology Branch, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3 (Canada); Department of Chemistry, Carleton University, Ottawa, ON K1S 5B6 (Canada); Letcher, Robert J., E-mail: robert.letcher@canada.ca [Wildlife and Landscape Directorate, Science and Technology Branch, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3 (Canada); Department of Chemistry, Carleton University, Ottawa, ON K1S 5B6 (Canada)

    2016-10-01

    The in vitro biotransformation and kinetics of six organophosphate triester (OPE) flame retardants were investigated in herring gulls (Larus argentatus) from the Great Lakes using a hepatic microsomal metabolism assay. Administration of each individual OPE (tri-n-butyl phosphate (TNBP), tris(2-butoxyethyl) phosphate (TBOEP), triphenyl phosphate (TPHP), triethyl phosphate (TEP), tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and tris(2-chloroisopropyl) phosphate (TCIPP)) to the in vitro assay (concentration range 0.01 to 10 μM) resulted in rapid depletion with the exception of TEP. Following the Michaelis-Menten enzyme kinetics model, a preliminary 2-minute incubation period was used to estimate the V{sub max} (± SE) values (i.e., the maximal rate of reaction for a saturated enzyme system), which ranged from 5.0 ± 0.4 (TPHP) to 29 ± 18 pmol/min/mg protein (TBOEP), as well as the K{sub M} (± SE) values (i.e., the OPE concentration corresponding to one half of the V{sub max}), which ranged from 9.8 ± 1 (TPHP) to 189 ± 135 nM (TBOEP). Biotransformation assays over a 100-minute incubation period revealed that TNBP was metabolized most rapidly (with a depletion rate of 73 ± 4 pmol/min/mg protein), followed by TBOEP (53 ± 8 pmol/min/mg), TCIPP (27 ± 1 pmol/min/mg), TPHP (22 ± 2 pmol/min/mg) and TDCIPP (8 ± 1 pmol/min/mg). In vitro biotransformation of OP triesters was clearly structure-dependent where non-halogenated alkyl OP triesters were metabolized more rapidly than halogenated alkyl triesters. Halogenated OP triesters were transformed to their respective diesters more efficiently relative to non-halogenated OP triesters. To our knowledge, this is the first study to investigate OP triester metabolism and OP diester formation in an avian or wildlife model system, which is important to understand the fate and biological activity of OPEs in an exposed organism. - Highlights: • The metabolism and kinetics of 6 OPEs were examined in herring gull liver

  15. Precision and relative effectiveness of a purse seine for sampling age-0 river herring in lakes

    Science.gov (United States)

    Devine, Matthew T.; Roy, Allison; Whiteley, Andrew R.; Gahagan, Benjamin I.; Armstrong, Michael P.; Jordaan, Adrian

    2018-01-01

    Stock assessments for anadromous river herring, collectively Alewife Alosa pseudoharengus and Blueback Herring A. aestivalis, lack adequate demographic information, particularly with respect to early life stages. Although sampling adult river herring is increasingly common throughout their range, currently no standardized, field‐based, analytical methods exist for estimating juvenile abundance in freshwater lakes. The objective of this research was to evaluate the relative effectiveness and sampling precision of a purse seine for estimating densities of age‐0 river herring in freshwater lakes. We used a purse seine to sample age‐0 river herring in June–September 2015 and June–July 2016 in 16 coastal freshwater lakes in the northeastern USA. Sampling effort varied from two seine hauls to more than 50 seine hauls per lake. Catch rates were highest in June and July, and sampling precision was maximized in July. Sampling at night (versus day) in open water (versus littoral areas) was most effective for capturing newly hatched larvae and juveniles up to ca. 100 mm TL. Bootstrap simulation results indicated that sampling precision of CPUE estimates increased with sampling effort, and there was a clear threshold beyond which increased effort resulted in negligible increases in precision. The effort required to produce precise CPUE estimates, as determined by the CV, was dependent on lake size; river herring densities could be estimated with up to 10 purse‐seine hauls (one‐two nights) in a small lake (50 ha). Fish collection techniques using a purse seine as described in this paper are likely to be effective for estimating recruit abundance of river herring in freshwater lakes across their range.

  16. Results from the first GPS tracking of roof-nesting Herring Gulls Larus argentatus in the UK

    NARCIS (Netherlands)

    Rock, P.; Camphuysen, C.J.; Shamoun-Baranes, J.; Ross-Smith, V.; Vaughan, I.P.

    2016-01-01

    Recent developments in GPS tracking technology allow the movements of bird species to be followed in ever-greater detail. Seabird research is benefiting greatly, due to the challenges of tracking species that often roam widely out at sea. Amongst the gulls, one of the pressing issues is to

  17. Breeding success of Oystercatcher, terns and gulls in the Danish Wadden Sea

    DEFF Research Database (Denmark)

    Bregnballe, Thomas; Thorup, Ole; Jensen, Peter Emil

    2015-01-01

    breeding of Sandwich Terns was recorded on Langli in most of the years during 2006-2010. The Lesser Black-backed Gulls and Herring Gulls that nested on Langli were fairly successful in raising young to fledging during 2009-2013, whereas Common Gulls suffered from predation by Herring Gulls and they hardly...

  18. Marine incursion: the freshwater herring of Lake Tanganyika are the product of a marine invasion into west Africa.

    Directory of Open Access Journals (Sweden)

    Anthony B Wilson

    Full Text Available The spectacular marine-like diversity of the endemic fauna of Lake Tanganyika, the oldest of the African Great Lakes, led early researchers to suggest that the lake must have once been connected to the ocean. Recent geophysical reconstructions clearly indicate that Lake Tanganyika formed by rifting in the African subcontinent and was never directly linked to the sea. Although the Lake has a high proportion of specialized endemics, the absence of close relatives outside Tanganyika has complicated phylogeographic reconstructions of the timing of lake colonization and intralacustrine diversification. The freshwater herring of Lake Tanganyika are members of a large group of pellonuline herring found in western and southern Africa, offering one of the best opportunities to trace the evolutionary history of members of Tanganyika's biota. Molecular phylogenetic reconstructions indicate that herring colonized West Africa 25-50MYA, at the end of a major marine incursion in the region. Pellonuline herring subsequently experienced an evolutionary radiation in West Africa, spreading across the continent and reaching East Africa's Lake Tanganyika during its early formation. While Lake Tanganyika has never been directly connected with the sea, the endemic freshwater herring of the lake are the descendents of an ancient marine incursion, a scenario which may also explain the origin of other Tanganyikan endemics.

  19. Species differences in total mercury concentration in gulls from the Gulf of Gdansk (Southern Baltic).

    Science.gov (United States)

    Szumiło-Pilarska, Emilia; Grajewska, Agnieszka; Falkowska, Lucyna; Hajdrych, Julia; Meissner, Włodzimierz; Frączek, Tomasz; Bełdowska, Magdalena; Bzoma, Szymon

    2016-01-01

    Aquatic birds occupy a high position in the trophic pyramid of the Baltic Sea. This means that they accumulate the greatest amount of harmful substances, including mercury, in their bodies. This element penetrates into their systems mainly via the alimentary canal. The amount of mercury absorbed from food depends on how badly the environment is polluted with this metal. The aim of this study was to discover the concentrations of total mercury (HgT) in the contour feathers, muscles, brain, lungs, liver, kidneys, heart and blood of four gull species Herring Gull (Larus argentatus), Common Gull (Larus canus), Black-headed Gull (Larus ridibundus) and Great Black-backed Gull (Larus marinus) and organic mercury (Hgorg) in the liver and brain of Herring Gull. The most important characteristic of the results obtained for the studied gulls was the statistically significant differences between the four species, probably resulting from their different diets-confirmed by stable-isotopes analysis (δ(15)N and δ(13)C). A logarithmic dependence was found between HgT in the blood and HgT in the brain of the Herring Gull. The authors suggest that among gulls burdened with the greatest mercury load, it is possible that the brain is protected by higher Hg accumulation in the muscles. The percentage share of Hgorg in the brain and liver of the Herring Gull depended on the concentration of HgT in these tissues and was always higher in the brain. In none of the cases, did the mercury levels assayed in the internal gulls' tissues exceed values associated with adverse health effects. Copyright © 2015 Elsevier GmbH. All rights reserved.

  20. Organochlorine concentrations in diseased vs. healthy gull chicks from the northern Baltic

    International Nuclear Information System (INIS)

    Hario, Martti; Hirvi, Juha-Pekka; Hollmen, Tuula; Rudbaeck, Eeva

    2004-01-01

    The population decline of the nominate lesser black-backed gull Larus fuscus fuscus in the Gulf of Finland (northern Baltic) is caused by an exceedingly high chick mortality due to diseases. The chick diseases include degeneration in various internal organs (primarily liver), inflammations (mainly intestinal), and sepsis, the final cause of death. The hypothesis of starvation causing intestinal inflammations (leading to sepsis) was tested by attempting to reproduce lesions in apparently healthy herring gull L. argentatus chicks in captivity. The herring gull chicks were provided a similar low food-intake frequency as observed for the diseased chicks in the wild. However, empty alimentary tract per se did not induce the intestinal inflammations and therefore, inflammations seem to be innate or caused by other environmental factors in the diseased lesser black-backed chicks. They had very high concentrations of PCB in their liver; but the concentrations were not significantly higher than those of the healthy herring gull chicks, indicating a common exposure area for both species (i.e. the Baltic Sea). When compared to NOEL and LOEL values for TEQs in bird eggs our TEQ levels clearly exceed most or all of the values associated with effects. Compared with published data on fish-eating waterbirds, the DDE concentrations in the diseased lesser black-backed chicks were well above the levels previously correlated with decreased reproduction, while the residues in apparently healthy herring gulls were below those levels. The DDE/PCB ratio in lesser black-backs was significantly elevated, indicating an increased exposure to DDTs as compared with most other Baltic and circumpolar seabirds. The possible exposure areas of DDT in relation to differential migration habits of the two gull species are discussed. - Elevated DDE/PCB ratio correlates with a high rate of chick diseases in the endangered nominate lesser black-backed gull

  1. Organochlorine concentrations in diseased vs. healthy gull chicks from the northern Baltic

    Energy Technology Data Exchange (ETDEWEB)

    Hario, Martti; Hirvi, Juha-Pekka; Hollmen, Tuula; Rudbaeck, Eeva

    2004-02-01

    The population decline of the nominate lesser black-backed gull Larus fuscus fuscus in the Gulf of Finland (northern Baltic) is caused by an exceedingly high chick mortality due to diseases. The chick diseases include degeneration in various internal organs (primarily liver), inflammations (mainly intestinal), and sepsis, the final cause of death. The hypothesis of starvation causing intestinal inflammations (leading to sepsis) was tested by attempting to reproduce lesions in apparently healthy herring gull L. argentatus chicks in captivity. The herring gull chicks were provided a similar low food-intake frequency as observed for the diseased chicks in the wild. However, empty alimentary tract per se did not induce the intestinal inflammations and therefore, inflammations seem to be innate or caused by other environmental factors in the diseased lesser black-backed chicks. They had very high concentrations of PCB in their liver; but the concentrations were not significantly higher than those of the healthy herring gull chicks, indicating a common exposure area for both species (i.e. the Baltic Sea). When compared to NOEL and LOEL values for TEQs in bird eggs our TEQ levels clearly exceed most or all of the values associated with effects. Compared with published data on fish-eating waterbirds, the DDE concentrations in the diseased lesser black-backed chicks were well above the levels previously correlated with decreased reproduction, while the residues in apparently healthy herring gulls were below those levels. The DDE/PCB ratio in lesser black-backs was significantly elevated, indicating an increased exposure to DDTs as compared with most other Baltic and circumpolar seabirds. The possible exposure areas of DDT in relation to differential migration habits of the two gull species are discussed. - Elevated DDE/PCB ratio correlates with a high rate of chick diseases in the endangered nominate lesser black-backed gull.

  2. Gulls Are Not "Seagulls"

    Science.gov (United States)

    Wheat, Maxwell Corydon, Jr.

    1976-01-01

    The word "seagull" is included in the dictionary because the term is so often applied by the lay persons to almost any gull they notice. However, this is a generalized term which ignores the wide and facinating variety of the species. This article discusses some of the species of gulls. (NQ)

  3. Organochlorine concentrations in diseased vs. healthy gull chicks from the northern Baltic.

    Science.gov (United States)

    Hario, Martti; Hirvi, Juha-Pekka; Hollmén, Tuula; Rudbäck, Eeva

    2004-01-01

    The population decline of the nominate lesser black-backed gull Larus fuscus fuscus in the Gulf of Finland (northern Baltic) is caused by an exceedingly high chick mortality due to diseases. The chick diseases include degeneration in various internal organs (primarily liver), inflammations (mainly intestinal), and sepsis, the final cause of death. The hypothesis of starvation causing intestinal inflammations (leading to sepsis) was tested by attempting to reproduce lesions in apparently healthy herring gull L. argentatus chicks in captivity. The herring gull chicks were provided a similar low food-intake frequency as observed for the diseased chicks in the wild. However, empty alimentary tract per se did not induce the intestinal inflammations and therefore, inflammations seem to be innate or caused by other environmental factors in the diseased lesser black-backed chicks. They had very high concentrations of PCB in their liver; but the concentrations were not significantly higher than those of the healthy herring gull chicks, indicating a common exposure area for both species (i.e. the Baltic Sea). When compared to NOEL and LOEL values for TEQs in bird eggs our TEQ levels clearly exceed most or all of the values associated with effects. Compared with published data on fish-eating waterbirds, the DDE concentrations in the diseased lesser black-backed chicks were well above the levels previously correlated with decreased reproduction, while the residues in apparently healthy herring gulls were below those levels. The DDE/PCB ratio in lesser black-backs was significantly elevated, indicating an increased exposure to DDTs as compared with most other Baltic and circumpolar seabirds. The possible exposure areas of DDT in relation to differential migration habits of the two gull species are discussed.

  4. The sound of danger: threat sensitivity to predator vocalizations, alarm calls, and novelty in gulls.

    Directory of Open Access Journals (Sweden)

    Sarah A MacLean

    Full Text Available The threat sensitivity hypothesis predicts that organisms will evaluate the relative danger of and respond differentially to varying degrees of predation threat. Doing so allows potential prey to balance the costs and benefits of anti-predator behaviors. Threat sensitivity has undergone limited testing in the auditory modality, and the relative threat level of auditory cues from different sources is difficult to infer across populations when variables such as background risk and experience are not properly controlled. We experimentally exposed a single population of two sympatric gull species to auditory stimuli representing a range of potential threats in order to compare the relative threat of heterospecific alarm calls, conspecific alarms calls, predator vocalizations, and novel auditory cues. Gulls were able to discriminate among a diverse set of threat indicators and respond in a graded manner commensurate with the level of threat. Vocalizations of two potential predators, the human voice and bald eagle call, differed in their threat level compared to each other and to alarm calls. Conspecific alarm calls were more threatening than heterospecfic alarm calls to the larger great black-backed gull, but the smaller herring gull weighed both equally. A novel cue elicited a response intermediate between known threats and a known non-threat in herring gulls, but not great black-backed gulls. Our results show that the relative threat level of auditory cues from different sources is highly species-dependent, and that caution should be exercised when comparing graded and threshold threat sensitive responses.

  5. Characterization of Escherichia coli populations from gulls, landfill trash, and wastewater using ribotyping.

    Science.gov (United States)

    Nelson, M; Jones, S H; Edwards, C; Ellis, J C

    2008-08-19

    Due to their opportunistic and gregarious nature, gulls may be important reservoirs and vectors for anthropogenically derived fecal pathogens in coastal areas. We used ribotyping, a genotypic bacterial source tracking method, to compare populations of Escherichia coli among herring gulls Larus argentatus, great black-backed gulls L. marinus, wastewater, and landfill trash in New Hampshire and Maine, USA. Concentrations of E. coli in gull feces varied widely among individuals, but were generally high (6.0 x 10(1) to 2.5 x 10(9) g(-1) wet weight). Of 39 E. coli isolates from L. argentatus, 67% had banding patterns that were > or = 90% similar to those from wastewater and trash, whereas only 39% of 36 L. marinus isolates exhibited > or = 90% similarity to these sources. Strains of E. coli from gulls matched (> or = 90% similarity) more strains from wastewater (39% matching) than from trash (15% matching). E. coli isolates from L. marinus feces exhibited a greater diversity of banding patterns than did isolates from L. argentatus. There were more unique E. coli banding patterns in trash samples than in wastewater, and higher diversity indices in the former compared to the latter. These findings suggest that both species of gulls, especially L. argentatus, obtain fecal bacteria from wastewater and landfill trash, which they may transport to recreational beaches and waters. Our results also indicate that E. coli populations may vary widely between gull species, and between the anthropogenic habitats that they frequent, i.e. landfills and wastewater treatment facilities.

  6. Radium-226 equilibrium between water and lake herring, Coregonus artedii, tissues attained within fish lifetime: confirmation in this species of one assumption in the simple linear concentration factor model

    International Nuclear Information System (INIS)

    Clulow, F.V.; Pyle, G.G.

    1997-01-01

    Equilibrium conditions are assumed in the simple linear concentration factor model commonly used in simulations of contaminant flow through ecosystems and in dose and risk calculations. Predictions derived from a power function model have suggested that if the time scale of the food-chain transfer is less than six years in fish, radium-226 equilibrium will not be achieved in nature, thereby violating the equilibrium requirement in the concentration factor model. Our results indicate 226 Ra equilibrium is achieved in a natural population of lake herring (Coregonus artedii), contrary to predictions of the power function model. (author)

  7. Plastic and Non-plastic Debris Ingestion in Three Gull Species Feeding in an Urban Landfill Environment.

    Science.gov (United States)

    Seif, S; Provencher, J F; Avery-Gomm, S; Daoust, P-Y; Mallory, M L; Smith, P A

    2018-04-01

    Plastic debris is recognized as a widespread, common and problematic environmental pollutant. An important consequence of this pollution is the ingestion of plastic debris by wildlife. Assessing the degree to which different species ingest plastics, and the potential effects of these plastics on their health are important research needs for understanding the impacts of plastic pollution. We examined debris (plastic and other types) ingestion in three sympatric overwintering gull species (Herring gulls Larus smithsonianus, Great Black-backed Gulls Larus marinus, and Iceland Gulls Larus glaucoides) to understand how debris ingestion differs among species, age classes and sexes in gulls. We also assessed how plastic burdens were associated with body condition to investigate how gulls may be affected by debris ingestion. There were no differences among the species, age classes or sexes in the incidence of debris ingestion (plastic or otherwise), the mass or number of debris pieces ingested. We found no correlation between ingested plastics burdens and individual condition. Gulls ingested plastic debris, but also showed high levels of other debris types as well, including metal, glass and building materials, including a metal piece of debris found within an abscess in the stomach. Thus, when the health effects of debris ingestion on gulls, and other species that ingest debris, is of interest, either from a physical or chemical perspective, it may be necessary to consider all debris types and not just plastic burdens as is often currently done for seabirds.

  8. Identification and characterization of a novel adenovirus in the cloacal bursa of gulls

    International Nuclear Information System (INIS)

    Bodewes, R.; Bildt, M.W.G. van de; Schapendonk, C.M.E.; Leeuwen, M. van; Boheemen, S. van; Jong, A.A.W. de; Osterhaus, A.D.M.E.; Smits, S.L.; Kuiken, T.

    2013-01-01

    Several viruses of the family of Adenoviridae are associated with disease in birds. Here we report the detection of a novel adenovirus in the cloacal bursa of herring gulls (Larus argentatus) and lesser black-backed gulls (Larus fuscus) that were found dead in the Netherlands in 2001. Histopathological analysis of the cloacal bursa revealed cytomegaly and karyomegaly with basophilic intranuclear inclusions typical for adenovirus infection. The presence of an adenovirus was confirmed by electron microscopy. By random PCR in combination with deep sequencing, sequences were detected that had the best hit with known adenoviruses. Phylogenetic analysis of complete coding sequences of the hexon, penton and polymerase genes indicates that this novel virus, tentatively named Gull adenovirus, belongs to the genus Aviadenovirus. The present study demonstrates that birds of the Laridae family are infected by family-specific adenoviruses that differ from known adenoviruses in other bird species. - Highlights: ► Lesions typical for adenovirus infection detected in cloacal bursa of dead gulls. ► Confirmation of adenovirus infection by electron microscopy and deep sequencing. ► Sequence analysis indicates that it is a novel adenovirus in the genus Aviadenovirus. ► The novel (Gull) adenovirus was detected in multiple organs of two species of gulls

  9. Spatio-temporal trends in the predation of large gulls by peregrine falcons (Falco peregrinus in an insular breeding population

    Directory of Open Access Journals (Sweden)

    Sutton Luke J.

    2017-12-01

    Full Text Available Individual diet specialization occurs in many populations of generalist predators, with specific individuals developing specialist strategies in their feeding behaviour. Intraspecific resource partitioning is hypothesised to be common amongst species in higher trophic levels where competition for resources is intense, and a key driver in breeding success and community structure. Though well-studied in other predators, there is sparse data on ecological specialization in raptors, which are important drivers of community and trophic structure. In this study, the breeding season diet of an insular population of peregrine falcons (Falco peregrinus was determined from indirect analysis of prey remains collected over three years. An unexpected result was the high proportion of large gulls (Laridae, of the genus Larus, in the diet of two breeding pairs of peregrines. Large gulls made up 18.44% by frequency of total prey recorded and 30.81% by biomass. Herring gulls (Larus argentatus were the most common large gull prey, with immatures most frequent (67.95% compared to adults (19.23%. Overall, most gulls predated were immatures (80.77%. Frequency of predation varied between breeding pairs and months, but was consistent over the three years. Most gulls were taken in April (37.17%, followed by May (19.23%, with a smaller peak of immature herring gulls taken in August and September. The pattern of regular predation by peregrines on large gulls is a new observation with important implications for understanding individual diet specialization in raptors, and its effect on bird populations and community structure.

  10. Are life histories of Norwegian fjord herring populations of Pacific ancestry similar to those of Atlantic or Pacific herring?

    Science.gov (United States)

    Mikkelsen, Nina; Pedersen, Torstein; dos Santos Schmidt, Thassya Christina; Falk-Petersen, Inger-Britt; Slotte, Aril

    2018-04-01

    Herring from two unexploited fjord populations, Lake Rossfjord (LRH, n = 100) and Balsfjord (BFH, n = 420) in northern Norway, were sampled in 2014 and 2015. Life history characteristics were analysed and compared to the oceanic Norwegian spring-spawning herring (NSSH), and other Atlantic and Pacific herring stocks. Genetic studies have shown that LRH and BFH are ancestors evolved from Pacific herring that hybridized with Atlantic herring. This study shows that both LRH and BFH mature at a relatively early age, at 2-3 years and ca. 4 years respectively, compared to ca. 5 years for NSSH. The spawning stocks of LRH and BFH consist of small fish and contain relatively few age classes. Both fjord populations have slow growth after sexual maturity; LRH has a very low asymptotic length (L∞ = 19.8 cm), while that of BFH is higher (L∞ of 28.5 cm); both these values being lower than that of NSSH (L∞ of ca. 37 cm). The somatic relative fecundity of LRH is 176.6 oocytes g- 1, while the somatic relative fecundity of recruit and repeat BFH spawners is 152.4 and 183.1 oocytes g- 1, respectively. These estimates are lower than those for NSSH and other Atlantic herring fjord populations, but comparable with other Pacific herring. Due to the smaller body sizes of the spawners in the LRH and BFH populations, absolute fecundity is much lower than in NSSH. The gonadosomatic indices of prespawning fish are similar in LRH and BFH, being slightly higher compared to the NSSH, but lower than values reported for Pacific herring. The natural mortality rates of LRH and BFH (M = 0.64 year- 1 and M = 0.76 year- 1, respectively) are much higher than in NSSH (M = 0.15 year- 1) and most other Atlantic herring populations, except the Lusterfjord herring. However, these high mortality rates are similar to those of several Pacific herring populations. It is concluded that LRH and BFH show low somatic growth and high natural mortality rate. These life history characteristics differ from those of

  11. Increased prevalence of antibiotic-resistant E. coli in gulls sampled in southcentral Alaska is associated with urban environments

    Science.gov (United States)

    Atterby, Clara; Ramey, Andrew M.; Gustafsson Hall, Gabriel; Jarhult, Josef; Borjesson, Stefan; Bonnedahl, Jonas

    2016-01-01

    BackgroundAntibiotic-resistant bacteria pose challenges to healthcare delivery systems globally; however, limited information is available regarding the prevalence and spread of such bacteria in the environment. The aim of this study was to compare the prevalence of antibiotic-resistant bacteria in large-bodied gulls (Larus spp.) at urban and remote locations in Southcentral Alaska to gain inference into the association between antibiotic resistance in wildlife and anthropogenically influenced habitats.MethodsEscherichia coli was cultured (n=115 isolates) from fecal samples of gulls (n=160) collected from a remote location, Middleton Island, and a more urban setting on the Kenai Peninsula.ResultsScreening of E. coli from fecal samples collected from glaucous-winged gulls (Larus glaucescens) at Middleton Island revealed 8% of isolates were resistant to one or more antibiotics and 2% of the isolates were resistant to three or more antibiotics. In contrast, 55% of E. coli isolates derived from fecal samples collected from large-bodied gulls (i.e. glaucous, herring [Larus argentatus], and potentially hybrid gulls) on the Kenai Peninsula were resistant to one or more antibiotics and 22% were resistant to three or more antibiotics. In addition, total of 16% of the gull samples from locations on the Kenai Peninsula harbored extended-spectrum cephalosporin-resistant E. coli isolates (extended-spectrum beta-lactamases [ESBL] and plasmid-encoded AmpC [pAmpC]), in contrast to Middleton Island where no ESBL- or pAmpC-producing isolates were detected.ConclusionOur findings indicate that increased prevalence of antibiotic resistance is associated with urban environments in Southcentral Alaska and presumably influenced by anthropogenic impacts. Further investigation is warranted to assess how migratory birds may maintain and spread antimicrobial-resistant bacteria of relevance to human and animal health.

  12. First feeding of larval herring

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Munk, Peter; Støttrup, Josianne

    1985-01-01

    The transition period from endogenous to exogenous feeding by larval herring was investigated in the laboratory for four herring stocks in order to evaluate the chances of survival at the time of fiest feeding. Observations on larval activity, feeding and growth were related to amount of yolk......, visual experience with potential prey organisms prior to first feeding and prey density. Herring larvae did not initiate exogenous feeding until around the time of yolk resorption. The timing of first feeding was not influenced by prior exposure to potential prey organisms during the yolk sac stage....... In the light of these observations, the ecological significance of the yolk sac stage is discussed. Initiation of exogenous feeding was delayed by 1-4 days at a low (7.5 nauplii .cntdot. l-1) compared to a high (120 nauplii .cntdot. l-1) prey density, but even at prey densities corresponding to the lower end...

  13. DDT-induced feminization of gull embryos

    International Nuclear Information System (INIS)

    Fry, D.M.; Toone, C.K.

    1981-01-01

    Injection of DDT [1, 1, 1-trichloro-2,2-bis(p-chlorophenyl)ethane] into gull eggs at concentrations comparable to those found in contaminated seabird eggs in 1970 induces abnormal development of ovarian tissue and oviducts in male embryos. Developmental feminization of males is associated with inability to breed as adults and may explain the highly skewed sex ratio and reduced number of male gulls breeding on Santa Barbara Island in southern California

  14. Salted herring brine as a coating or additive for herring (Clupea harengus) products — A source of natural antioxidants?

    DEFF Research Database (Denmark)

    Albertos, Irene; Gringer, Nina; Rico, Daniel

    2016-01-01

    The objective of this study was to characterise herring brine and assess its use as natural antioxidant in herring preservation. Herring brines from different marinated products (brine from fillet-ripened spice-cured herring SC, traditional barrel-salted spice-cured herring TSp and brine from...

  15. Volatile Methylsiloxanes and Organophosphate Esters in the Eggs of European Starlings (Sturnus vulgaris) and Congeneric Gull Species from Locations across Canada.

    Science.gov (United States)

    Lu, Zhe; Martin, Pamela A; Burgess, Neil M; Champoux, Louise; Elliott, John E; Baressi, Enzo; De Silva, Amila O; de Solla, Shane R; Letcher, Robert J

    2017-09-05

    Volatile methylsiloxanes (VMSs) and organophosphate esters (OPEs) are two suites of chemicals that are of environmental concern as organic contaminants, but little is known about the exposure of wildlife to these contaminants, particularly in birds, in terrestrial and aquatic ecosystems. The present study investigates the spatial distributions of nine cyclic and linear VMSs and 17 OPEs in the eggs of European starlings (Sturnus vulgaris) and three congeneric gull species (i.e., herring gull (Larus argentatus), glaucous-winged gull (L. glaucescens), and California gull (L. californicus)) from nesting sites across Canada. ∑VMS concentrations for all bird eggs were dominated by decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), and octamethylcyclotetrasiloxane (D4). With European starlings, birds breeding adjacent to landfill sites had eggs containing significantly greater ∑VMS concentrations (median: 178 ng g -1 wet weight (ww)) compared with those from the urban industrial (20 ng g -1 ww) and rural sites (1.3 ng g -1 ww), indicating that the landfills are important sources of VMSs to Canadian terrestrial environments. In gull eggs, the median ∑VMS concentrations were up to 254 ng g -1 ww and suggested greater detection frequencies and levels of VMSs in aquatic- versus terrestrial-feeding birds in Canada. In contrast, the detection frequency of OPEs in all European starling and gull eggs was lower than 16%. This suggested that low dietary exposure or rapid metabolism of accumulated OPEs occurs in aquatic feeding birds and may warrant further investigation for the elucidation of the reasons for these differences.

  16. Aerial estimation of the size of gull breeding colonies

    Science.gov (United States)

    Kadlec, J.A.; Drury, W.H.

    1968-01-01

    Counts on photographs and visual estimates of the numbers of territorial gulls are usually reliable indicators of the number of gull nests, but single visual estimates are not adequate to measure the number of nests in individual colonies. To properly interpret gull counts requires that several islands with known numbers of nests be photographed to establish the ratio of gulls to nests applicable for a given local census. Visual estimates are adequate to determine total breeding gull numbers by regions. Neither visual estimates nor photography will reliably detect annual changes of less than about 2.5 percent.

  17. True navigation in migrating gulls requires intact olfactory nerves

    DEFF Research Database (Denmark)

    Wikelski, Martin; Arriero, Elena; Gagliardo, Anna

    2015-01-01

    debated. In this experiment we subjected adult lesser black-backed gulls migrating from their Finnish/Russian breeding grounds (from >60°N) to Africa (to ... of the trigeminal nerve sectioned oriented towards their population-specific migratory corridor. Thus, air-borne olfactory information seems to be important for migrating gulls to navigate successfully in some circumstances....

  18. Estimates of numbers of kelp gulls and Kerguelen and Antarctic ...

    African Journals Online (AJOL)

    Four species are regular breeders at the islands: Subantarctic skua Catharacta antarctica, kelp gull Larus dominicanus, Antarctic tern Sterna vittata and Kerguelen tern S. virgata. The latter three species currently each have populations of below 150 breeding pairs at the islands. Kelp gull numbers appear to be relatively ...

  19. Seasonal patterns in numbers of Kelp Gulls Larus dominicanus ...

    African Journals Online (AJOL)

    Between 66% and 80% of Kelp Gulls recorded around Port Elizabeth were in adult plumage. It is assumed that adults breeding outside of the Port Elizabeth area move into the area after breeding. During their first year Kelp Gulls showed distinct periods of influx — thought to be due to the fledging of local birds — followed ...

  20. Effects of oil transferred from incubating gulls to their eggs

    Science.gov (United States)

    King, K.A.; LeFever, C.A.

    1979-01-01

    No. 2 fuel oil, or water, was applied to the breast feathers of incubating laughing gulls trapped at their nest site on an island colony in Texas. Gulls were released after treatment and allowed to incubate their eggs for 5 days. Oil was transferred from the feathers of incubating adults to their eggs and resulted in 41% embryo mortality compared with 2% in controls.

  1. Temporal patterns of migration and spawning of river herring in coastal Massachusetts

    Science.gov (United States)

    Rosset, Julianne; Roy, Allison; Gahagan, Benjamin I.; Whiteley, Andrew R.; Armstrong, Michael P.; Sheppard, John J.; Jordaan, Adrian

    2017-01-01

    Migrations of springtime Alewife Alosa pseudoharengus and Blueback Herring A. aestivalis, collectively referred to as river herring, are monitored in many rivers along the Atlantic coast to estimate population sizes. While these estimates give an indication of annual differences in the number of returning adults, links to the subsequent timing and duration of spawning and freshwater juvenile productivity remain equivocal. In this study, we captured juvenile river herring at night in 20 coastal Massachusetts lakes using a purse seine and extracted otoliths to derive daily fish ages and back-calculate spawn dates. Estimates of spawning dates were compared with fishway counts of migrating adults to assess differences in migration timing and the timing and duration of spawning. We observed a distinct delay between the beginning of the adult migration run and the start of spawning, ranging from 7 to 28 d across the 20 lakes. Spawning continued 13–48 d after adults stopped migrating into freshwater, further demonstrating a pronounced delay in spawning following migration. Across the study sites the duration of spawning (43–76 d) was longer but not related to the duration of migration (29–66 d). The extended spawning period is consistent with recent studies suggesting that Alewives are indeterminate spawners. The long duration in freshwater provides the opportunity for top-down (i.e., predation on zooplankton) and bottom-up (i.e., food for avian, fish, and other predators) effects, with implications for freshwater food webs and nutrient cycling. General patterns of spawn timing and duration can be incorporated into population models and used to estimate temporal changes in productivity associated with variable timing and density of spawning river herring in lakes.

  2. Unraveling biocomplexity of Northeast Atlantic herring stocks using SNP markers

    DEFF Research Database (Denmark)

    Bekkevold, Dorte; Limborg, Morten; Helyar, Sarah

    2012-01-01

    Atlantic herring (Clupea harengus) exhibit biocomplexity, with widespread, geographically explicit populations that perform long‐range migration to common feeding and wintering areas, where they are exploited by fisheries. This means that exploited stocks do not describe discrete units, thereby c...... and spatial dynamics applicable to stock assessment methods, as well as presenting a traceability tool for certification of herring and herring products...

  3. Flame retardants in eggs of four gull species (Laridae) from breeding sites spanning Atlantic to Pacific Canada

    International Nuclear Information System (INIS)

    Chen Da; Letcher, Robert J.; Burgess, Neil M.; Champoux, Louise; Elliott, John E.; Hebert, Craig E.; Martin, Pamela; Wayland, Mark; Chip Weseloh, D.V.; Wilson, Laurie

    2012-01-01

    To compare legacy and emerging flame retardant (FR) contamination in Canadian marine and freshwater ecosystems, eggs of four gull species (Laridae) were collected from 26 colonies spanning Pacific to Atlantic Canada, including in the Great Lakes basin. Fourteen polybrominated diphenyl ether (PBDE) congeners and 20 non-PBDE FRs were analyzed, but BDE-47, -99, -100, -153, -154 and -209, hexabromocyclododecane (HBCD) and Dechlorane Plus (DP) syn- and anti-isomers were common, and where concentrations of ∑PBDEs (37–610 ng/g wet weight, ww) ≫ HBCD (0.5–12 ng/g ww) > ∑DP (not quantifiable-5.5 ng/g ww). All other FRs were generally not detectable. Stable nitrogen and carbon isotopes used as dietary tracers provided insights into the diet choice influences on the exposure sources and contamination patterns (e.g., PBDE congener compositions) for individual gulls from the same colony. Eggs from gulls breeding near metropolitan regions of higher human densities showed greater PBDE burdens than from other ecosystems. - Highlights: ► We investigated flame retardants in eggs of four gull species spanning Canada. ► Concentrations of ∑PBDE ≫ hexabromocyclododecane > ∑Dechlorane Plus in eggs. ► Stable nitrogen and carbon isotopes revealed diet sources of flame retardants. ► Human density near breeding sites influenced flame retardant burdens in eggs. - Various flame retardants were found in eggs of four gull species from sites across Canada, and levels were influenced by location, ecosystem, diet and proximity to human populations.

  4. Synthetic biology as red herring.

    Science.gov (United States)

    Preston, Beth

    2013-12-01

    It has become commonplace to say that with the advent of technologies like synthetic biology the line between artifacts and living organisms, policed by metaphysicians since antiquity, is beginning to blur. But that line began to blur 10,000 years ago when plants and animals were first domesticated; and has been thoroughly blurred at least since agriculture became the dominant human subsistence pattern many millennia ago. Synthetic biology is ultimately only a late and unexceptional offshoot of this prehistoric development. From this perspective, then, synthetic biology is a red herring, distracting us from more thorough philosophical consideration of the most truly revolutionary human practice-agriculture. In the first section of this paper I will make this case with regard to ontology, arguing that synthetic biology crosses no ontological lines that were not crossed already in the Neolithic. In the second section I will construct a parallel case with regard to cognition, arguing that synthetic biology as biological engineering represents no cognitive advance over what was required for domestication and the new agricultural subsistence pattern it grounds. In the final section I will make the case with regard to human existence, arguing that synthetic biology, even if wildly successful, is not in a position to cause significant existential change in what it is to be human over and above the massive existential change caused by the transition to agriculture. I conclude that a longer historical perspective casts new light on some important issues in philosophy of technology and environmental philosophy. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. The role of 'conservatism' in herring migrations

    NARCIS (Netherlands)

    Corten, A.

    2002-01-01

    Herring (Clupea harengus) migrations tend to remain constant over periods of several years or even decades, despite environmental variation. When a migration pattern is changed, apparently in response to an environmental stimulus, the change in migratory behavior sometimes lasts longer than the

  6. Parathion alters incubation behavior of laughing gulls

    Science.gov (United States)

    White, D.H.; Mitchell, C.A.; Hill, E.F.

    1983-01-01

    One member of each pair of incubating laughing gulls at 9 nests was trapped, orally dosed with either 6 mg/kg parathion in corn oil or corn oil alone, and marked about the neck with red dye. Each nest was marked with a numbered stake and the treatment was recorded. A pilot study with captive laughing gulls had determined the proper dosage of parathion that would significantly inhibit their brain AChE activity (about 50% of normal) without overt signs of poisoning. After dosing, birds were released and the nests were observed for 2 1/2 days from a blind on the nesting island. The activities of the birds at each marked nest were recorded at 10-minute intervals. Results indicated that on the day of treatment there was no difference (P greater than 0.05, Chi-square test) in the proportion of time spent on the nest between treated and control birds. However, birds dosed with 6 mg/kg parathion spent significantly less time incubating on days 2 and 3 than did birds receiving only corn oil. By noon on the third day, sharing of nest duties between pair members in the treated group had approached normal, indicating recovery from parathion intoxication. These findings suggest that sublethal exposure of nesting birds to an organophosphate (OP) insecticide, such as parathion, may result in decreased nest attentiveness, thereby making the clutch more susceptible to predation or egg failure. Behavioral changes caused by sublethal OP exposure could be especially detrimental in avian species where only one pair member incubates or where both members are exposed in species sharing nest duties.

  7. Seasonal dynamics of Atlantic herring (Clupea harengus L.) populations spawning in the vicinity of marginal habitats.

    Science.gov (United States)

    Eggers, Florian; Slotte, Aril; Libungan, Lísa Anne; Johannessen, Arne; Kvamme, Cecilie; Moland, Even; Olsen, Esben M; Nash, Richard D M

    2014-01-01

    Gillnet sampling and analyses of otolith shape, vertebral count and growth indicated the presence of three putative Atlantic herring (Clupea harengus L.) populations mixing together over the spawning season February-June inside and outside an inland brackish water lake (Landvikvannet) in southern Norway. Peak spawning of oceanic Norwegian spring spawners and coastal Skagerrak spring spawners occurred in March-April with small proportions of spawners entering the lake. In comparison, spawning of Landvik herring peaked in May-June with high proportions found inside the lake, which could be explained by local adaptations to the environmental conditions and seasonal changes of this marginal habitat. The 1.85 km(2) lake was characterized by oxygen depletion occurring between 2.5 and 5 m depth between March and June. This was followed by changes in salinity from 1-7‰ in the 0-1 m surface layer to levels of 20-25‰ deeper than 10 m. In comparison, outside the 3 km long narrow channel connecting the lake with the neighboring fjord, no anoxic conditions were found. Here salinity in the surface layer increased over the season from 10 to 25‰, whereas deeper than 5 m it was stable at around 35‰. Temperature at 0-5 m depth increased significantly over the season in both habitats, from 7 to 14 °C outside and 5 to 17 °C inside the lake. Despite differences in peak spawning and utilization of the lake habitat between the three putative populations, there was an apparent temporal and spatial overlap in spawning stages suggesting potential interbreeding in accordance with the metapopulation concept.

  8. Seasonal dynamics of Atlantic herring (Clupea harengus L. populations spawning in the vicinity of marginal habitats.

    Directory of Open Access Journals (Sweden)

    Florian Eggers

    Full Text Available Gillnet sampling and analyses of otolith shape, vertebral count and growth indicated the presence of three putative Atlantic herring (Clupea harengus L. populations mixing together over the spawning season February-June inside and outside an inland brackish water lake (Landvikvannet in southern Norway. Peak spawning of oceanic Norwegian spring spawners and coastal Skagerrak spring spawners occurred in March-April with small proportions of spawners entering the lake. In comparison, spawning of Landvik herring peaked in May-June with high proportions found inside the lake, which could be explained by local adaptations to the environmental conditions and seasonal changes of this marginal habitat. The 1.85 km(2 lake was characterized by oxygen depletion occurring between 2.5 and 5 m depth between March and June. This was followed by changes in salinity from 1-7‰ in the 0-1 m surface layer to levels of 20-25‰ deeper than 10 m. In comparison, outside the 3 km long narrow channel connecting the lake with the neighboring fjord, no anoxic conditions were found. Here salinity in the surface layer increased over the season from 10 to 25‰, whereas deeper than 5 m it was stable at around 35‰. Temperature at 0-5 m depth increased significantly over the season in both habitats, from 7 to 14 °C outside and 5 to 17 °C inside the lake. Despite differences in peak spawning and utilization of the lake habitat between the three putative populations, there was an apparent temporal and spatial overlap in spawning stages suggesting potential interbreeding in accordance with the metapopulation concept.

  9. "Everything revolves around the herring": the Heiltsuk-herring relationship through time

    Directory of Open Access Journals (Sweden)

    Alisha M. Gauvreau

    2017-06-01

    Full Text Available Pacific herring (Clupea pallasii is foundational to many social-ecological systems of the North American coast. The indigenous people of Heiltsuk First Nation on the central coast of British Columbia, Canada have depended on this forage fish for food, social, ceremonial, and economic purposes for millennia. Our research documents social, ecological, and cultural aspects of Heiltsuk First Nation's relationship with Pacific herring and how this relationship has changed over time. We describe and discuss (1 how Heiltsuk social institutions, local and traditional ecological knowledge, and worldview have informed herring management strategies from pre-contact times until present, and (2 how post-contact changes in state-led herring management and other social and institutional developments in British Columbia have affected the role and transmission of Heiltsuk local knowledge and management of herring. By working in close partnership with Heiltsuk decision-makers, and by conducting interviews with Heiltsuk knowledge holders, we ensured that the data gathered would be relevant, applicable, and valuable to the Heiltsuk community. Our research therefore serves as an example of how state fisheries agencies could improve relationships with indigenous communities by engaging in more collaborative data collection, and our results suggest the potential for joint learning and improvement in fisheries management through collaboration during the design of management and harvesting plans. Our research has relevance at the global level because we identify some of the steps that may be taken to help overcome institutionalized inertia and attain more equitable power relationships for sustainable fisheries management.

  10. Ichthyophonus hoferi disease in the herring in Norwegian waters

    OpenAIRE

    Hjeltnes, Brit K.; Skagen, Dankert W.

    1992-01-01

    After the discovery of I. hoferi disease in Norwegian spring spawning herring in summer 1991, a program for systematic surveillance of the disease in the herring in Norwegian waters was developed. The programme, which aims primarily at monitoring the prevalence of the disease, is described. Macroscopic lesions in the heart emerged as the standard diagnostic criterium. The results so far indicate that the situation for Norwegian spring spawning herring is not alarming, ...

  11. Distribution and diet of Ivory gulls (Pagophila eburnea) in the North Water polynya

    OpenAIRE

    Karnovsky, NJ; Hobson, KA; Brown, ZW; Hunt, GL

    2009-01-01

    Ivory gulls (Pagophila eburnea, Phipps, 1774), one of the world's least-known species, have declined throughout their range in recent years. This study describes the patterns of ivory gull use of the North Water polynya, a large polynya that occurs every year near ivory gull breeding sites on Ellesmere Island, Nunavut, Canada. We conducted at-sea surveys from Canadian icebreakers during the summers of 1997-99. In 1998, stomach contents of five ivory gulls were analyzed. We measured stable iso...

  12. Distribution and numbers of breeding ivory gulls Pagophila eburnea in Severnaja Zemlja, Russian Arctic

    NARCIS (Netherlands)

    Volkov, AE; de Korte, J.

    The ivory gull Pagophila eburnea has a semi-circumpolar distribution with breeding sites in the High Arctic. Data about ivory gulls in the Severnaja Zemlja Archipelago (Siberia) were collected from 1991 to 1995. The numbers of breeding ivory gulls and their egg-laying period are correlated with the

  13. Frozen herring as raw material for spice-salting

    NARCIS (Netherlands)

    Stefansson, G.; Nielsen, H.H.; Skara, T.; Schubring, R.; Oehlenschlager, J.; Luten, J.

    2000-01-01

    One batch of herring (Clupea harengus) was spice-salted fresh and as thawed after 32 days of frozen storage at -24 °C. After salting, samples of both groups were sent to participating laboratories in Iceland, Denmark, Norway, Germany and England. The herring was kept at 5 ± 1 °C and sampled three

  14. Is disease an important mortality factor for Pacific herring?

    Science.gov (United States)

    Hershberger, Paul

    2005-01-01

    Marine pelagic forage fishes, including sardines, anchovies, and herring, undergo large oscillations in population abundance. Although over-fishing can have a dramatic impact in reducing population size, this anthropogenic perturbation cannot fully account for all population declines because natural oscillations in marine pelagic fish biomasses occurred prior to the onset of commercial fishing. Among the herring metapopulation in Puget Sound / Straight of Georgia, the mean estimated annual mortality, exclusive of commercial fishing, increased from 20% in the late 1970’s and early 1980’s to 64-87% during 1996-1999. This natural mortality affects primarily the older age cohorts and resulted in recent decreased median ages of adult herring from age 4-6 cohorts to age 2-3 cohorts that die prior to iteroparous spawning. Surveys of wild herring from the region indicate that the protozoan parasite Ichthyophonus sp., is currently ubiquitous among Pacific herring populations in Washington and British Columbia, and prevalence of infection increase directly with herring age, from 12% among juveniles to 58% among the underrepresented age 6+ cohorts. Ichthyophonus can be highly pathogenic to immunologically naïve Pacific herring, causing 80% mortality 2 mo. after exposure in the laboratory. Current laboratory-based studies are underway to determine whether natural Ichthyophonus infections are terminal for the host, and whether these infections account for the decreasing median age of wild Pacific herring populations in recent years.

  15. Environmental Factors and Natural Resource Stock: Atlantic Herring case

    Energy Technology Data Exchange (ETDEWEB)

    Cho, J.H. [Korea Maritime Institute, Seoul (Korea); John, M. Gate [University of Rhode Island, Kingston (United States)

    2001-12-01

    Atlantic herrings have held the important position as fish-baits in the marine ecosystem such as major baits in fishing lobsters. The Atlantic herring is sensitively influenced by the environmental factors of the marine ecosystem, such as the temperature of seawater, the amount of planktons, and the submarine deposit of the habitat. In the immature phase of herrings, especially, they are very sensitive of the low temperature of seawater. This study analyzes the correlation between two-year-old imported herring resources and the temperature of seawater, measured by a satellite. The area of measuring temperature is limited to the spawning ground of Atlantic herrings. As results of the analysis, the coefficient is 0.69, which means that the environmental factors should be very seriously considered in explaining the change of fishing resources. 12 refs., 4 figs., 1 tab.

  16. Annotated Bibliography for Lake Erie. Volume I. Biological,

    Science.gov (United States)

    1974-10-01

    maculosa Le Sueur; calico bass, or Lake Erie bass, Pomoxis sparoides Lacepede. (SM) 52. Reardslee, Clark S. 1944. Bonapart’s gull on the Niagara...of the burbot, Lota lota maculosa (LeSueur), in Lake Erie. Trans. Am. Fish. Soc. 80:163-173. Growth studies were made on 2,329 Lake Erie burbot...almo -- hystus; whitefish, oe onus albus; common shad salmon, Coregonus a upelformis; aobony pike, Lepisosteus bison; spotted burbot, Lota maculosa ; and

  17. Improving smoked herring quality by gamma irradiation

    International Nuclear Information System (INIS)

    Zahran, D.A.; Abd El-Wahab, S.A.; Hendy, B.A.

    2009-01-01

    Smoked herring which is a highly purchasable product in Egypt, was exposed to different gamma irradiation doses (1.5,3.0 and 5.0 kGy) and stored at environmental temperature (12± 2 deg C) until spoilage of the control. Microbiological, chemical and sensory analyses were performed throughout storage to monitor the quality attributes. It is worthy to mention that irradiation reduced the population of bacteria and the effect was more pronounced at the highest dose used (5.0 kGy). At the same time 1.5 kGy completely eliminated staphylococcus aureus (coagulase + ve) and coliforms. By chemical analysis, there was significant decrease in average moisture content by different gamma irradiation doses and storage. Although the average thiobarbituric acid reactive substances (TBARS) increased slightly by γ-irradiation, this increase was highly significant by storage . At the same time there was a significant (p< 0.05)decrease in the average trimethylamine (TMA) value of all irradiated samples compared with unirradiated control, this value increased significantly by storage. interestingly, the average histamine value decreased significantly in all irradiated samples. The sensory analysis revealed a highly significant difference in the average acceptability scores between different irradiation doses used and also by storage. Therefore it could be concluded that the quality of smoked herring during storage at environmental temperature (12 ± 2 deg C) could be improved by using 5.0 kGy γ -irradiation

  18. Sensory Properties of Frozen Herring (Clupea harengus) from Different Catch Seasons and Locations

    DEFF Research Database (Denmark)

    Hyldig, Grethe; Jørgensen, Bo Munk; Undeland, Ingrid

    2012-01-01

    Freezing of herring (Clupea harengus) for human consumption is increasing in the Nordic herring industry, either onboard the fishing vessels or right after landing. The quality of frozen herring as a raw material does not only depend on the frozen storage conditions applied, but also...... on compositional features, something which in turn can vary with season and catching ground. To unravel the link between biological variations, basic muscle composition, and sensory properties of frozen herring, a unique herring raw material was caught by commercial fishing vessels at three locations: around...... the utilization of herring for frozen storage for human consumption....

  19. Population diversity in Pacific herring of the Puget Sound, USA.

    Science.gov (United States)

    Siple, Margaret C; Francis, Tessa B

    2016-01-01

    Demographic, functional, or habitat diversity can confer stability on populations via portfolio effects (PEs) that integrate across multiple ecological responses and buffer against environmental impacts. The prevalence of these PEs in aquatic organisms is as yet unknown, and can be difficult to quantify; however, understanding mechanisms that stabilize populations in the face of environmental change is a key concern in ecology. Here, we examine PEs in Pacific herring (Clupea pallasii) in Puget Sound (USA) using a 40-year time series of biomass data for 19 distinct spawning population units collected using two survey types. Multivariate auto-regressive state-space models show independent dynamics among spawning subpopulations, suggesting that variation in herring production is partially driven by local effects at spawning grounds or during the earliest life history stages. This independence at the subpopulation level confers a stabilizing effect on the overall Puget Sound spawning stock, with herring being as much as three times more stable in the face of environmental perturbation than a single population unit of the same size. Herring populations within Puget Sound are highly asynchronous but share a common negative growth rate and may be influenced by the Pacific Decadal Oscillation. The biocomplexity in the herring stock shown here demonstrates that preserving spatial and demographic diversity can increase the stability of this herring population and its availability as a resource for consumers.

  20. Comparative biology and population mixing among local, coastal and offshore Atlantic herring (Clupea harengus) in the North Sea, Skagerrak, Kattegat and western Baltic

    Science.gov (United States)

    Slotte, Aril; Johannessen, Arne; Kvamme, Cecilie; Clausen, Lotte Worsøe; Nash, Richard D. M.

    2017-01-01

    The population structure of Atlantic herring (Clupea harengus) from 13 local, coastal and offshore areas of the North Sea, Skagerrak, Kattegat and western Baltic (northeast Atlantic) was studied using biological and environmental data from 1970–2015. The objective was to identify distinct populations by comparing variability in the temporal and spatial phenotypic characteristics and evaluate the potential for mixing of populations in time and space. The populations varied in biological characteristics such as mean vertebral counts (VS), growth and maturity ogives. Generalized additive models indicated temporally stable VS in the North Sea and western Baltic, whereas intra-annual temporal variation of VS occurred in other areas. High variability of VS within a population was not affected by environmental factors such as temperature and salinity. Consequently, seasonal VS variability can be explained by the presence or absence of herring populations as they migrate between areas. The three main populations identified in this paper correspond to the three managed stocks in this area: Norwegian spring spawners (NSS), western Baltic spring spawners (WBSS) and North Sea autumn spawners (NSAS). In addition, several local populations were identified in fjords or lakes along the coast, but our analyses could not detect direct mixing of local populations with the three main populations. Our results highlight the importance of recognizing herring dynamics and understanding the mixing of populations as a challenge for management of herring. PMID:29084258

  1. Effectiveness of a refuge for Lake Trout in Western Lake Superior II: Simulation of future performance

    Science.gov (United States)

    Akins, Andrea L; Hansen, Michael J.; Seider, Michael J.

    2015-01-01

    Historically, Lake Superior supported one of the largest and most diverse Lake Trout Salvelinus namaycush fisheries in the Laurentian Great Lakes, but Lake Trout stocks collapsed due to excessive fishery exploitation and predation by Sea Lampreys Petromyzon marinus. Lake Trout stocking, Sea Lamprey control, and fishery regulations, including a refuge encompassing Gull Island Shoal (Apostle Islands region), were used to enable recovery of Lake Trout stocks that used this historically important spawning shoal. Our objective was to determine whether future sustainability of Lake Trout stocks will depend on the presence of the Gull Island Shoal Refuge. We constructed a stochastic age-structured simulation model to assess the effect of maintaining the refuge as a harvest management tool versus removing the refuge. In general, median abundances of age-4, age-4 and older (age-4+), and age-8+ fish collapsed at lower instantaneous fishing mortality rates (F) when the refuge was removed than when the refuge was maintained. With the refuge in place, the F that resulted in collapse depended on the rate of movement into and out of the refuge. Too many fish stayed in the refuge when movement was low (0–2%), and too many fish became vulnerable to fishing when movement was high (≥22%); thus, the refuge was more effective at intermediate rates of movement (10–11%). With the refuge in place, extinction did not occur at any simulated level of F, whereas refuge removal led to extinction at all combinations of commercial F and recreational F. Our results indicate that the Lake Trout population would be sustained by the refuge at all simulated F-values, whereas removal of the refuge would risk population collapse at much lower F (0.700–0.744). Therefore, the Gull Island Shoal Refuge is needed to sustain the Lake Trout population in eastern Wisconsin waters of Lake Superior.

  2. 76 FR 79610 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Adjustment to 2012 Annual...

    Science.gov (United States)

    2011-12-22

    ... account for catch overages in 2010 and to prevent overfishing. DATES: Public comments must be received no... FR 48874). Although herring is not overfished and is not experiencing overfishing, the herring annual...

  3. NEFSC 1998 Atlantic Herring Acoustic/Midwater Trawl Survey (DE9810, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Atlantic herring acoustic survey is a fisheries independent survey that provides scientific data for Atlantic herring assessments in the U.S. mid-Atlantic...

  4. NEFSC 2011 Atlantic Herring Acoustic/Midwater Trawl Survey (DE1108, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Atlantic herring acoustic survey is a fisheries independent survey that provides scientific data for Atlantic herring assessments in the U.S. mid-Atlantic...

  5. NEFSC 2002 Atlantic Herring Acoustic/Midwater Trawl Survey (DE0208, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Atlantic herring acoustic survey is a fisheries independent survey that provides scientific data for Atlantic herring assessments in the U.S. mid-Atlantic...

  6. NEFSC 2006 Atlantic Herring Acoustic/Midwater Trawl Survey (DE0615, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Atlantic herring acoustic survey is a fisheries independent survey that provides scientific data for Atlantic herring assessments in the U.S. mid-Atlantic...

  7. NEFSC 1999 Atlantic Herring Acoustic/Midwater Trawl Survey (DE9909, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Atlantic herring acoustic survey is a fisheries independent survey that provides scientific data for Atlantic herring assessments in the U.S. mid-Atlantic...

  8. NEFSC 2008 Atlantic Herring Acoustic/Midwater Trawl Survey (DE0809, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Atlantic herring acoustic survey is a fisheries independent survey that provides scientific data for Atlantic herring assessments in the U.S. mid-Atlantic...

  9. NEFSC 2003 Atlantic Herring Acoustic/Midwater Trawl Survey (DE0308, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Atlantic herring acoustic survey is a fisheries independent survey that provides scientific data for Atlantic herring assessments in the U.S. mid-Atlantic...

  10. NEFSC 2004 Atlantic Herring Acoustic/Midwater Trawl Survey (DE0413, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Atlantic herring acoustic survey is a fisheries independent survey that provides scientific data for Atlantic herring assessments in the U.S. mid-Atlantic...

  11. NEFSC 2010 Atlantic Herring Acoustic/Midwater Trawl Survey (DE1010, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Atlantic herring acoustic survey is a fisheries independent survey that provides scientific data for Atlantic herring assessments in the U.S. mid-Atlantic...

  12. NEFSC 2000 Atlantic Herring Acoustic/Midwater Trawl Survey (DE0008, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Atlantic herring acoustic survey is a fisheries independent survey that provides scientific data for Atlantic herring assessments in the U.S. mid-Atlantic...

  13. NEFSC 2001 Atlantic Herring Acoustic/Midwater Trawl Survey (DE0109, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Atlantic herring acoustic survey is a fisheries independent survey that provides scientific data for Atlantic herring assessments in the U.S. mid-Atlantic...

  14. NEFSC 2005 Atlantic Herring Acoustic/Midwater Trawl Survey (DE0512, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Atlantic herring acoustic survey is a fisheries independent survey that provides scientific data for Atlantic herring assessments in the U.S. mid-Atlantic...

  15. NEFSC 2007 Atlantic Herring Acoustic/Midwater Trawl Survey (DE0710, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Atlantic herring acoustic survey is a fisheries independent survey that provides scientific data for Atlantic herring assessments in the U.S. mid-Atlantic...

  16. NEFSC 2012 Atlantic Herring Acoustic/Midwater Trawl Survey (PC1206, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Atlantic herring acoustic survey is a fisheries independent survey that provides scientific data for Atlantic herring assessments in the U.S. mid-Atlantic...

  17. NEFSC 1998 Atlantic Herring Acoustic/Midwater Trawl Survey (DE9809, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Atlantic herring acoustic survey is a fisheries independent survey that provides scientific data for Atlantic herring assessments in the U.S. mid-Atlantic...

  18. NEFSC 2009 Atlantic Herring Acoustic/Midwater Trawl Survey (DE0910, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Atlantic herring acoustic survey is a fisheries independent survey that provides scientific data for Atlantic herring assessments in the U.S. mid-Atlantic...

  19. Exposure to parvalbumin allergen and aerosols among herring processing workers.

    Science.gov (United States)

    Dahlman-Höglund, Anna; Renström, Anne; Acevedo, Fernando; Andersson, Eva

    2013-10-01

    There are increasing reports of allergies and respiratory symptoms among workers in the fish processing industry, coinciding with an increasing use of high-pressure water in the processing plants. However, few studies have measured exposure in these work environments. The aim of this study was to characterize the occupational exposure of workers to herring antigen and to screen environmental factors at a herring (Clupea harengus) plant in which new and more encapsulated filleting machines had been installed. To assist in this, a method to assess airborne exposure to herring allergen was needed. Exposure to airborne herring antigen, mould spores, and endotoxin were measured during work. Antigen exposure was assessed using a newly developed sensitive (detection limit, 0.1 ng ml(-1)) rabbit polyclonal sandwich enzyme-linked immunosorbent assay against the major herring muscle protein allergen, parvalbumin. Aerosols were measured by mass concentration (DataRAM) and number of particles (Climet I-500). Personal geometric mean herring allergen exposure was 986 ng m(-3) at the old filleting workstations and 725 ng m(-3) at the new workstations (difference not significant). Outside the production room, the level was ~130 ng m(-3). Number of particles and mass concentration were both significantly lower around the new machines than around the old machines (P < 0.001 and P < 0.0001, respectively). The highest particle count was seen for the 0.3-0.5 μm fraction, with more than 400,000 particles per cubic metre air. Endotoxin concentration in the air varied between 3 and 92 EU m(-3), with the highest levels when the catch mainly contained herring that had eaten krill or seaweed. We developed a sensitive method to detect herring antigen. High exposure to herring antigen was measured during filleting work. The particles in the air around the fillet machines were mainly <0.5 μm and the newer encapsulated machines generated fewer particles. It is important to reduce occupational

  20. 50 CFR 648.207 - Herring Research Set-Aside (RSA).

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Herring Research Set-Aside (RSA). 648.207... Measures for the Atlantic Herring Fishery § 648.207 Herring Research Set-Aside (RSA). (a) NMFS shall... authorized to utilize RSA, based on the selection criteria described in the RFP. (d) NMFS shall consider each...

  1. 75 FR 29574 - Final Legislative Environmental Impact Statement for the Harvest of Glaucous-Winged Gull Eggs by...

    Science.gov (United States)

    2010-05-26

    ... for the Harvest of Glaucous-Winged Gull Eggs by the Huna Tlingit in Glacier Bay National Park AGENCY... Impact Statement for the Harvest of Glaucous-Winged Gull Eggs by the Huna Tlingit in Glacier Bay National... Environmental Impact Statement (LEIS) for the harvest of glaucous-winged gull eggs by the Huna Tlingit in...

  2. Comparison of gull-specific assays targeting 16S rRNA gene of Catellicoccus marimammalium and Streptococcus spp.

    Science.gov (United States)

    Gulls have been implicated as a source of fecal contamination in inland and coastal waters. Only one gull-specific assay is currently available (i.e., gull2 qPCR assay). This assay is based on the 16S rRNA gene of Catellicocclls marimammalium and has showed a high level of host-s...

  3. Pacific and Atlantic herring produce burst pulse sounds.

    Science.gov (United States)

    Wilson, Ben; Batty, Robert S; Dill, Lawrence M

    2004-02-07

    The commercial importance of Pacific and Atlantic herring (Clupea pallasii and Clupea harengus) has ensured that much of their biology has received attention. However, their sound production remains poorly studied. We describe the sounds made by captive wild-caught herring. Pacific herring produce distinctive bursts of pulses, termed Fast Repetitive Tick (FRT) sounds. These trains of broadband pulses (1.7-22 kHz) lasted between 0.6 s and 7.6 s. Most were produced at night; feeding regime did not affect their frequency, and fish produced FRT sounds without direct access to the air. Digestive gas or gulped air transfer to the swim bladder, therefore, do not appear to be responsible for FRT sound generation. Atlantic herring also produce FRT sounds, and video analysis showed an association with bubble expulsion from the anal duct region (i.e. from the gut or swim bladder). To the best of the authors' knowledge, sound production by such means has not previously been described. The function(s) of these sounds are unknown, but as the per capita rates of sound production by fish at higher densities were greater, social mediation appears likely. These sounds may have consequences for our understanding of herring behaviour and the effects of noise pollution.

  4. Sanctuaries for lake trout in the Great Lakes

    Science.gov (United States)

    Stanley, Jon G.; Eshenroder, Randy L.; Hartman, Wilbur L.

    1987-01-01

    Populations of lake trout, severely depleted in Lake Superior and virtually extirpated from the other Great Lakes because of sea lamprey predation and intense fishing, are now maintained by annual plantings of hatchery-reared fish in Lakes Michigan, Huron, and Ontario and parts of Lake Superior. The extensive coastal areas of the Great Lakes and proximity to large populations resulted in fishing pressure on planted lake trout heavy enough to push annual mortality associated with sport and commercial fisheries well above the critical level needed to reestablish self-sustaining stocks. The interagency, international program for rehabilitating lake trout includes controlling sea lamprey abundance, stocking hatchery-reared lake trout, managing the catch, and establishing sanctuaries where harvest is prohibited. Three lake trout sanctuaries have been established in Lake Michigan: the Fox Island Sanctuary of 121, 500 ha, in the Chippewa-Ottawa Treaty fishing zone in the northern region of the lake; the Milwaukee Reef Sanctuary of 160, 000 ha in midlake, in boundary waters of Michigan and Wisconsin; and Julian's Reef Sanctuary of 6, 500 ha, in Illinois waters. In northern Lake Huron, Drummond Island Sanctuary of 55, 000 ha is two thirds in Indian treaty-ceded waters in Michigan and one third in Ontario waters of Canada. A second sanctuary, Six Fathom Bank-Yankee Reef Sanctuary, in central Lake Huron contains 168, 000 ha. Sanctuary status for the Canadian areas remains to be approved by the Provincial government. In Lake Superior, sanctuaries protect the spawning grounds of Gull Island Shoal (70, 000 ha) and Devils Island Shoal (44, 000 ha) in Wisconsin's Apostle Island area. These seven sanctuaries, established by the several States and agreed upon by the States, Indian tribes, the U.S. Department of the Interior, and the Province of Ontario, contribute toward solving an interjurisdictional fishery problem.

  5. The Efficiency of an Integrated Program Using Falconry to Deter Gulls from Landfills

    Directory of Open Access Journals (Sweden)

    Ericka Thiériot

    2015-04-01

    Full Text Available Gulls are commonly attracted to landfills, and managers are often required to implement cost-effective and socially accepted deterrence programs. Our objective was to evaluate the effectiveness of an intensive program that integrated the use of trained birds of prey, pyrotechnics, and playback of gull distress calls at a landfill located close to a large ring-billed gull (Larus delawarensis colony near Montreal, Quebec, Canada. We used long-term survey data on bird use of the landfill, conducted behavioral observations of gulls during one season and tracked birds fitted with GPS data loggers. We also carried out observations at another landfill located farther from the colony, where less refuse was brought and where a limited culling program was conducted. The integrated program based on falconry resulted in a 98% decrease in the annual total number of gulls counted each day between 1995 and 2014. A separate study indicated that the local breeding population of ring-billed gulls increased and then declined during this period but remained relatively large. In 2010, there was an average (±SE of 59 ± 15 gulls/day using the site with falconry and only 0.4% ± 0.2% of these birds were feeding. At the other site, there was an average of 347 ± 55 gulls/day and 13% ± 3% were feeding. Twenty-two gulls tracked from the colony made 41 trips towards the landfills: twenty-five percent of the trips that passed by the site with falconry resulted in a stopover that lasted 22 ± 7 min compared to 85% at the other landfill lasting 63 ± 15 min. We concluded that the integrated program using falconry, which we consider more socially acceptable than selective culling, was effective in reducing the number of gulls at the landfill.

  6. Comparison of Gull Feces-specific Assays Targeting the 16S rRNA Gene of Catellicoccus Marimammalium and Streptococcus spp.

    Science.gov (United States)

    Two novel gull-specific qPCR assays were developed using 16S rRNA gene sequences from gull fecal clone libraries: a SYBR-green-based assay targeting Streptococcus spp. (i.e., gull3) and a TaqMan qPCR assay targeting Catellicoccus marimammalium (i.e., gull4). The main objectives ...

  7. Antioxidant activities and functional properties of protein and peptide fractions isolated from salted herring brine

    DEFF Research Database (Denmark)

    Taheri, Ali; Farvin, Sabeena; Jacobsen, Charlotte

    2014-01-01

    In the present study proteins isolated from herring brine, which is a by-product of marinated herring production were evaluated for their functional properties and antioxidant activity. Herring brine was collected from the local herring industry and proteins were precipitated by adjusting the p...... to delay iron catalyzed lipid oxidation in 5% fish oil in water emulsions and the 10–50kDa fraction was the best. These results show the potential of proteins and peptide fractions recovered from waste water from the herring industry as source of natural antioxidants for use in food products....

  8. Effects of lake trout refuges on lake whitefish and cisco in the Apostle Islands Region of Lake Superior

    Science.gov (United States)

    Zuccarino-Crowe , Chiara M.; Taylor, William W.; Hansen, Michael J.; Seider, Michael J.; Krueger, Charles C.

    2016-01-01

    Lake trout refuges in the Apostle Islands region of Lake Superior are analogous to the concept of marine protected areas. These refuges, established specifically for lake trout (Salvelinus namaycush) and closed to most forms of recreational and commercial fishing, were implicated as one of several management actions leading to successful rehabilitation of Lake Superior lake trout. To investigate the potential significance of Gull Island Shoal and Devils Island Shoal refuges for populations of not only lake trout but also other fish species, relative abundances of lake trout, lake whitefish (Coregonus clupeaformis), and cisco (Coregonus artedi) were compared between areas sampled inside versus outside of refuge boundaries. During 1982–2010, lake trout relative abundance was higher and increased faster inside the refuges, where lake trout fishing was prohibited, than outside the refuges. Over the same period, lake whitefish relative abundance increased faster inside than outside the refuges. Both evaluations provided clear evidence that refuges protected these species. In contrast, trends in relative abundance of cisco, a prey item of lake trout, did not differ significantly between areas inside and outside the refuges. This result did not suggest indirect or cascading refuge effects due to changes in predator levels. Overall, this study highlights the potential of species-specific refuges to benefit other fish species beyond those that were the refuges' original target. Improved understanding of refuge effects on multiple species of Great Lakes fishes can be valuable for developing rationales for refuge establishment and predicting associated fish community-level effects.

  9. Biomonitoring of coastal areas in Tunisia: Stable isotope and trace element analysis in the Yellow-legged Gull

    International Nuclear Information System (INIS)

    Abdennadher, Aida; Ramirez, Francisco; Romdhane, Mohamed Salah; Ruiz, Xavier; Jover, Lluis; Sanpera, Carolina

    2010-01-01

    We used Yellow-legged Gull (YLG) chicks to monitor trace elements in Tunisian areas subject to different pollution stresses: urban contamination (Chikly), industrial pollution (Thyna) and an unpolluted area (Kneis). We measured trace element concentrations (Hg, Se and Pb) in chick feathers. We also assessed their feeding ecology by analyzing both regurgitates and stable isotopes (SIA) in chick feathers and in their prey, to determine the main entry route of pollutants. SIA revealed that YLG feed mainly on aquatic resources from the Lake of Tunis (Chikly colony) and the Gulf of Gabes (Thyna and Kneis colonies). Moreover, the enriched δ 15 N found in feathers from Chikly are attributed to the eutrophication of the Lake of Tunis. Hg and Se were higher in Kneis and Thyna colonies, in agreement with the higher consumption of marine resources and the greater availability of these elements resulting from the impact of the industrial activity in the area. Pb concentrations were higher in Chikly, related to the heavier traffic around the Lake of Tunis and the use of leaded gasoline.

  10. Distribution of juvenile Pacific herring relative to environmental and geospatial factors in Prince William Sound, Alaska

    Science.gov (United States)

    Lewandoski, Sean; Bishop, Mary Anne

    2018-01-01

    Documenting distribution patterns of juvenile Pacific herring (Clupea pallasii) can clarify habitat preferences and provide insight into ecological factors influencing early life survival. However, few analyses relating juvenile Pacific herring density to habitat characteristics have been conducted. We sampled age-0 Pacific herring in nine bays and fjords distributed throughout Alaska's Prince William Sound during November over a 3-year period (2013-2015) and investigated associations between catch rate and habitat covariates using generalized linear mixed models. Our results indicated that the night-time distribution of age-0 Pacific herring in the pelagic environment was influenced by proximity to eelgrass (Zostera marina) beds, salinity, and water depth. Age-0 Pacific herring catch rate was negatively associated with tow depth, with herring favoring shallower water across the range of depths sampled (7.2-35.4 m). In addition, Pacific herring distribution was positively associated with fresher water within the sampled salinity gradient (24.1-32.3 psu) and proximity to eelgrass beds. Seasonal changes in juvenile Pacific herring distribution were investigated by sampling one bay over a seven month period (October-April). Age-0 Pacific herring tended to remain in the inner bay region throughout the seven months, while age-1 Pacific herring had shifted from the inner to the outer bay by spring (March-April). Additionally, catch rate of age-0 Pacific herring in areas where ice breakup had just occurred was higher than in open water, suggesting that age-0 herring preferentially select ice-covered habitats when available. Based on our results we recommend that habitat preferences of age-0 Pacific herring should be considered in the development of Pacific herring year-class strength indices from catch data.

  11. Review of Ruegen herring larvae survey project 2011

    NARCIS (Netherlands)

    Dickey-Collas, M.; Nash, R.D.M.

    2011-01-01

    At the request of the Johann Heinrich von Thünen Institut (vTI), IOR Rostock, a return review of the German Rügen herring larval survey (RHLS) project took place on the 24th to 26th January 2011, following on from a similar review in November 2006. Mark Dickey-Collas (Wageningen IMARES) and Richard

  12. Technology of puddings made of Pacific herring milt

    Directory of Open Access Journals (Sweden)

    Dement'eva N. V.

    2016-09-01

    Full Text Available The technology of culinary products (puddings of finely ground Pacific herring milt has been experimentally proved. The standard physics and chemical, organoleptic, microbiological methods for food analysis have been used. The main raw material is frozen milt of Pacific herring. Fresh eggs, drinking cream, berries (cranberries, raspberries, strawberries, etc. frozen and fresh, sugar, and soda have been used as additional materials. The ratio of main components in production of puddings from Pacific herring milt is: milt 35–40 %, cream 20–25 %, eggs 15–22 %. The recipes of sweet puddings of milt with the addition of berries have been developed. The effect of duration of whipping protein mass on puddings' organoleptic parameters has been found experimentally. The recommended duration of whipping is from 3 to 5 minutes, this increases the amount of pudding mass lifting after the whipping of not less than 40 % of the original and provides the necessary structure in the finished product after heat treatment. The rational heat treatment of puddings' baking has been substantiated – at the temperature of 150 °C, with the duration of heat treatment for 20 minutes, which provides high organoleptic characteristics and safety of the finished product. The recommended shelf life of the finished product of not more than 72 hours at the temperature of 2–6 °C has been determined. On the basis of the research the technology of new kinds of culinary fish products – puddings of Pacific herring milt allowing obtain culinary products with high organoleptic characteristics – has been developed. The unique chemical composition combined (milk, eggs, cream and berries provides a basis for classification of new products as functional food. Additional involvement in food production little used milt of herring species of fish enables to expand the range of fish culinary products and increase the rate of food use of water origin raw material.

  13. Molecular characterization of extended-spectrum-cephalosporin-resistant Enterobacteriaceae from wild kelp gulls in South America

    NARCIS (Netherlands)

    Liakopoulos, Apostolos; Olsen, Björn; Geurts, Yvon; Artursson, Karin; Berg, Charlotte; Mevius, Dik J.; Bonnedahl, Jonas

    2016-01-01

    Extended-spectrum-cephalosporin-resistant Enterobacteriaceae are a public health concern due to limited treatment options. Here, we report on the occurrence and the molecular characteristics of extended-spectrum-cephalosporin-resistant Enterobacteriaceae recovered from wild birds (kelp gulls).

  14. ESBL-producing Escherichia coli in Swedish gulls-A case of environmental pollution from humans?

    Directory of Open Access Journals (Sweden)

    Clara Atterby

    Full Text Available ESBL-producing bacteria are present in wildlife and the environment might serve as a resistance reservoir. Wild gulls have been described as frequent carriers of ESBL-producing E. coli strains with genotypic characteristics similar to strains found in humans. Therefore, potential dissemination of antibiotic resistance genes and bacteria between the human population and wildlife need to be further investigated. Occurrence and characterization of ESBL-producing E. coli in Swedish wild gulls were assessed and compared to isolates from humans, livestock and surface water collected in the same country and similar time-period. Occurrence of ESBL-producing E. coli in Swedish gulls is about three times higher in gulls compared to Swedish community carriers (17% versus 5% and the genetic characteristics of the ESBL-producing E. coli population in Swedish wild gulls and Swedish human are similar. ESBL-plasmids IncF- and IncI1-type carrying ESBL-genes blaCTX-M-15 or blaCTX-M-14 were most common in isolates from both gulls and humans, but there was limited evidence of clonal transmission. Isolates from Swedish surface water harbored similar genetic characteristics, which highlights surface waters as potential dissemination routes between wildlife and the human population. Even in a low-prevalence country such as Sweden, the occurrence of ESBL producing E. coli in wild gulls and the human population appears to be connected and the occurrence of ESBL-producing E. coli in Swedish gulls is likely a case of environmental pollution.

  15. Geographic, temporal, and age-specific variation in diets of Glaucous Gulls in western Alaska

    Science.gov (United States)

    Schmutz, J.A.; Hobson, K.A.

    1998-01-01

    We collected boluses and food remains of adult Glaucous Gulls (Larus hyperboreus) at or near nests and chicks, and digestive tracts from adults at three sites on the Yukon-Kuskokwim Delta, Alaska that differed in proximity to marine and terrestrial foods. We observed both geographic and temporal variation in diet; gulls consumed proportionately more terrestrial prey after peak hatch in late June, and gulls near the coast consumed proportionately more marine prey than gulls at two inland areas. Goslings occurred in > 60% of all samples from these inland areas. We compared these data to those from a previous study in western Alaska and found no marked differences. Evidence for similar patterns of geographic and temporal variation in diet was found using measurements of stable-carbon and nitrogen isotopes in gull and prey tissues. Stable isotope analysis further revealed that adult gulls consumed proportionately more marine prey (saffron cod, Eleginus gracilis) than they fed to their young. Using isotopic models, we estimated that 7-22% and 10-23% of the diet of adult and juvenile Glaucous Gulls, respectively, was comprised of terrestrial species. In addition to significant age-related variation, dietary estimates varied among geographic areas and between pre- and post-hatch periods. Overall, our isotopic estimates of the contribution of terrestrial prey to the diet of Glaucous Gulls was less than what may be inferred from conventional methods of diet analysis. Our study emphasizes the benefit of combining stable-isotope and conventional analyses to infer temporal and geographic changes in diet of wild birds and other organisms.

  16. ESBL-producing Escherichia coli in Swedish gulls-A case of environmental pollution from humans?

    Science.gov (United States)

    Atterby, Clara; Börjesson, Stefan; Ny, Sofia; Järhult, Josef D; Byfors, Sara; Bonnedahl, Jonas

    2017-01-01

    ESBL-producing bacteria are present in wildlife and the environment might serve as a resistance reservoir. Wild gulls have been described as frequent carriers of ESBL-producing E. coli strains with genotypic characteristics similar to strains found in humans. Therefore, potential dissemination of antibiotic resistance genes and bacteria between the human population and wildlife need to be further investigated. Occurrence and characterization of ESBL-producing E. coli in Swedish wild gulls were assessed and compared to isolates from humans, livestock and surface water collected in the same country and similar time-period. Occurrence of ESBL-producing E. coli in Swedish gulls is about three times higher in gulls compared to Swedish community carriers (17% versus 5%) and the genetic characteristics of the ESBL-producing E. coli population in Swedish wild gulls and Swedish human are similar. ESBL-plasmids IncF- and IncI1-type carrying ESBL-genes blaCTX-M-15 or blaCTX-M-14 were most common in isolates from both gulls and humans, but there was limited evidence of clonal transmission. Isolates from Swedish surface water harbored similar genetic characteristics, which highlights surface waters as potential dissemination routes between wildlife and the human population. Even in a low-prevalence country such as Sweden, the occurrence of ESBL producing E. coli in wild gulls and the human population appears to be connected and the occurrence of ESBL-producing E. coli in Swedish gulls is likely a case of environmental pollution.

  17. Does predation by grey seals (Halichoerus grypus) affect Bothnian Sea herring stock estimates?

    DEFF Research Database (Denmark)

    Gårdmark, Anna; Östman, Örjan; Nielsen, Anders

    2012-01-01

    when accounting for seal predation, this did not change the conclusions about drivers of herring dynamics. Accounting for grey seal predation is important for abundance estimates of old herring, but currently not for SSB estimates, given the great uncertainties in the standard assessment. The grey seal...... fivefold since 1985. Its main prey, herring (Clupea harrengus), is a key species for fisheries in the region. Yet, current stock assessments assume constant natural mortality, leading to a risk of biased stock estimates with increasing predation and misleading analyses of herring population dynamics. We...... estimated grey seal predation from diet data and reanalysed herring spawning stock biomass (SSB) during 1973–2009. Accounting for predation increased the herring SSB 16% (maximum 19%), but this was within the confidence intervals when ignoring predation. Although mortality in older individuals was inflated...

  18. Textural and biochemical changes during ripening of old-fashioned salted herrings

    DEFF Research Database (Denmark)

    Christensen, Mette; Andersen, Eva; Christensen, Line

    2011-01-01

    the ripening period could be explained by free-radical-induced cross-linking of myosin and the formation of aggregates. In addition, degradation of these aggregates correlated with the decrease in hardness observed at 371 days. CONCLUSIONS: Texture changes during ripening of salted herrings can be explained...... of salted herrings. The aim of this study was to measure the texture changes during ripening using two differentmethods and to correlate the texture changeswith brine composition andwith biochemical modifications at themolecular level. RESULTS: During ripening (up to 151 days), hardness was higher in salted...... herrings compared to raw herrings, irrespective of the brine composition. However, the increase in hardness of herring prepared with extra brine occurred later. After prolonged storage (371 days), hardness was found for both batches to decrease to the level of raw herring. The increase in hardness during...

  19. Quantifying fall migration of Ross's gulls (Rhodostethia rosea) past Point Barrow, Alaska

    Science.gov (United States)

    Uher-Koch, Brian D.; Davis, Shanti E.; Maftei, Mark; Gesmundo, Callie; Suydam, R.S.; Mallory, Mark L.

    2014-01-01

    The Ross's gull (Rhodostethia rosea) is a poorly known seabird of the circumpolar Arctic. The only place in the world where Ross's gulls are known to congregate is in the near-shore waters around Point Barrow, Alaska where they undertake an annual passage in late fall. Ross's gulls seen at Point Barrow are presumed to originate from nesting colonies in Siberia, but neither their origin nor their destination has been confirmed. Current estimates of the global population of Ross's gulls are based largely on expert opinion, and the only reliable population estimate is derived from extrapolations from previous counts conducted at Point Barrow, but these data are now over 25 years old. In order to update and clarify the status of this species in Alaska, our study quantified the timing, number, and flight direction of Ross's gulls passing Point Barrow in 2011. We recorded up to two-thirds of the estimated global population of Ross's gulls (≥ 27,000 individuals) over 39 days with numbers peaking on 16 October when we observed over 7,000 birds during a three-hour period.

  20. Migration patterns of post-spawning Pacific herring in a subarctic sound

    Science.gov (United States)

    Bishop, Mary Anne; Eiler, John H.

    2018-01-01

    Understanding the distribution of Pacific herring (Clupea pallasii) can be challenging because spawning, feeding and overwintering may take place in different areas separated by 1000s of kilometers. Along the northern Gulf of Alaska, Pacific herring movements after spring spawning are largely unknown. During the fall and spring, herring have been seen moving from the Gulf of Alaska into Prince William Sound, a large embayment, suggesting that fish spawning in the Sound migrate out into the Gulf of Alaska. We acoustic-tagged 69 adult herring on spawning grounds in Prince William Sound during April 2013 to determine seasonal migratory patterns. We monitored departures from the spawning grounds as well as herring arrivals and movements between the major entrances connecting Prince William Sound and the Gulf of Alaska. Departures of herring from the spawning grounds coincided with cessation of major spawning events in the immediate area. After spawning, 43 of 69 tagged herring (62%) moved to the entrances of Prince William Sound over a span of 104 d, although most fish arrived within 10 d of their departure from the spawning grounds. A large proportion remained in these areas until mid-June, most likely foraging on the seasonal bloom of large, Neocalanus copepods. Pulses of tagged herring detected during September and October at Montague Strait suggest that some herring returned from the Gulf of Alaska. Intermittent detections at Montague Strait and the Port Bainbridge passages from September through early January (when the transmitters expired) indicate that herring schools are highly mobile and are overwintering in this area. The pattern of detections at the entrances to Prince William Sound suggest that some herring remain in the Gulf of Alaska until late winter. The results of this study confirm the connectivity between local herring stocks in Prince William Sound and the Gulf of Alaska.

  1. Energetic Cost of Ichthyophonus Infection in Juvenile Pacific Herring (Clupea pallasii)

    OpenAIRE

    Johanna J. Vollenweider; Jake L. Gregg; Ron A. Heintz; Paul K. Hershberger

    2011-01-01

    The energetic costs of fasting and Ichthyophonus infection were measured in juvenile Pacific herring (Clupea pallasii) in a lab setting at three temperatures. Infected herring incurred significant energetic costs, the magnitude of which depended on fish condition at the time of infection (fat versus lean). Herring that were fed continually and were in relatively good condition at the time of infection (fat) never stored lipid despite ad libitum feeding. In feeding herrin...

  2. Sensory properties of marinated herring (Clupea harengus) processed from raw material from commercial landings

    DEFF Research Database (Denmark)

    Nielsen, Durita; Hyldig, Grethe; Nielsen, Jette

    2005-01-01

    Sensory properties of marinated herring processed from raw material from Danish commercial catches were described and related to fishing season and biological, chemical and functional properties. Herring was caught on five cruises and stored on board in tanks or ice. The sensory profile of marina......Sensory properties of marinated herring processed from raw material from Danish commercial catches were described and related to fishing season and biological, chemical and functional properties. Herring was caught on five cruises and stored on board in tanks or ice. The sensory profile...

  3. Baltic herring fisheries management: stakeholder views to frame the problem

    DEFF Research Database (Denmark)

    Haapasaari, Päivi Elisabet; Mäntyniemi, Samu; Kuikka, Sakari

    2012-01-01

    Comprehensive problem framing that includes different perspectives is essential for holistic understanding of complex problems and as the first step in building models. We involved five stakeholders to frame the management problem of the Central Baltic herring fishery. By using the Bayesian belief...... nongovernmental organization included markets and fishing industry influences. Management measures were considered to have a relatively small impact on the development of the herring stock; their impact on socioeconomic objectives was greater. Overall, the framings by these stakeholders propose a focus...... networks (BBNs) approach, the views of the stakeholders were built into graphical influence diagrams representing variables and their dependencies. The views of the scientists involved concentrated on biological concerns, whereas the fisher, the manager, and the representative of an environmental...

  4. Interacting trophic forcing and the population dynamics of herring

    DEFF Research Database (Denmark)

    Lindegren, Martin; Ostman, Orjan; Gardmark, Anna

    2011-01-01

    -up nor top-down, but rather through multiple external and internal drivers. While in many studies single drivers have been identified, potential synergies of multiple factors, as well as their relative importance in regulating population dynamics of small pelagic fish, is a largely unresolved issue....... Using a statistical, age-structured modeling approach, we demonstrate the relative importance and influence of bottom-up (e.g., climate, zooplankton availability) and top-down (i.e., fishing and predation) factors on the population dynamics of Bothnian Sea herring (Clupea harengus) throughout its life...... cycle. Our results indicate significant bottom-up effects of zooplankton and interspecific competition from sprat (Sprattus sprattus), particularly on younger age classes of herring. Although top-down forcing through fishing and predation by grey seals (Halichoerus grypus) and Atlantic cod (Gadus morhua...

  5. The high diversity of arsenolipids in herring fillet (Clupea harengus).

    Science.gov (United States)

    Lischka, S; Arroyo-Abad, U; Mattusch, J; Kühn, A; Piechotta, Ch

    2013-06-15

    Arsenolipids represent a relevant step in the biosynthesis of organoarsenicals from inorganic arsenic compounds. Their fate after human consumption is still uncertain. By means of a HPLC-ICP-MS/ESI-Q-TOF-MS method, 16 lipid soluble arsenic compounds, including seven formerly unknown organoarsenicals, have been identified in commercial herring fillet. The structural assignment was done by exact mass and high resolution MS/MS data. This is the first identification of arsenolipids in herring (Clupea harengus). They contribute with (3.6±0.2) mg kg(-1) arsenic to 62.3% of the total arsenic content of (5.7±0.3) mg of arsenic per kg dry mass. Current studies indicate that a metabolization by humans to cancerous dimethylarsinic acid is very likely. The presented results are highly relevant as herring is a very popular food fish species in Europe. Moreover, the screening of different fish species revealed that arsenolipids are more widespread than previously assumed. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Food web changes under ocean acidification promote herring larvae survival.

    Science.gov (United States)

    Sswat, Michael; Stiasny, Martina H; Taucher, Jan; Algueró-Muñiz, Maria; Bach, Lennart T; Jutfelt, Fredrik; Riebesell, Ulf; Clemmesen, Catriona

    2018-05-01

    Ocean acidification-the decrease in seawater pH due to rising CO 2 concentrations-has been shown to lower survival in early life stages of fish and, as a consequence, the recruitment of populations including commercially important species. To date, ocean-acidification studies with fish larvae have focused on the direct physiological impacts of elevated CO 2 , but largely ignored the potential effects of ocean acidification on food web interactions. In an in situ mesocosm study on Atlantic herring (Clupea harengus) larvae as top predators in a pelagic food web, we account for indirect CO 2 effects on larval survival mediated by changes in food availability. The community was exposed to projected end-of-the-century CO 2 conditions (~760 µatm pCO 2 ) over a period of 113 days. In contrast with laboratory studies that reported a decrease in fish survival, the survival of the herring larvae in situ was significantly enhanced by 19 ± 2%. Analysis of the plankton community dynamics suggested that the herring larvae benefitted from a CO 2 -stimulated increase in primary production. Such indirect effects may counteract the possible direct negative effects of ocean acidification on the survival of fish early life stages. These findings emphasize the need to assess the food web effects of ocean acidification on fish larvae before we can predict even the sign of change in fish recruitment in a high-CO 2 ocean.

  7. Passive immunization of Pacific herring against viral hemorrhagic septicemia.

    Science.gov (United States)

    Hershberger, P.K.; Gregg, J.L.; Grady, C.A.; LaPatra, S.E.; Winton, J.R.

    2011-01-01

    The plasma of Pacific herring Clupea pallasii that survived laboratory-induced viral hemorrhagic septicemia (VHS) epizootics contained humoral substances that, when injected into naive animals, conferred passive immunity against the disease. Among groups exposed to viral hemorrhagic septicemia virus (VHSV), injection of donor plasma from VHS survivors resulted in significantly greater survival (50%) and significantly lower tissue titers (1.5 x 10(5) plaque-forming units [PFU]/g) than the injection of plasma from VHSV-naive donors (6% survival; 3.7 x 10(6) PFU/g). Additionally, the magnitude of the protective immune response increased during the postexposure period; plasma that was collected from survivors at 123 d postexposure (931 degree-days) provided greater protection than plasma collected from survivors at 60 d postexposure (409 degree-days). These results provide proof of concept that the VHSV exposure history of Pacific herring populations can be determined post hoc; furthermore, the results can be used as the foundation for developing additional high-throughput diagnostic techniques that may be effective at quantifying herd immunity and forecasting the potential for future VHS epizootics in populations of wild Pacific herring.

  8. NODC Standard Format Herring Survey Population Density and Distribution (F057) Data (1976-1977) (NODC Accession 0014189)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data type contains data from aircraft surveys of herring schools. These data were collected to provide information on herring population density and...

  9. High‐resolution acoustic indices of Atlantic herring (Clupea harengus) paving the way for inclusion of migration patterns in management considerations of herring in ICES Divisions IIIa and SD 22‐24

    DEFF Research Database (Denmark)

    Stæhr, Karl-Johan; Worsøe Clausen, Lotte

    2012-01-01

    Herring catches in the Western Baltic, Kattegat and Skagerrak consist of a mixture of stocks; the two predominant stocks are the spring‐spawning Western Baltic herring stock and the North Sea autumn‐spawning herring (NSAS), and the mixing follows an age‐ and season‐dependent pattern with high var...

  10. 77 FR 10978 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Adjustment to 2012 Annual...

    Science.gov (United States)

    2012-02-24

    ... to prevent overfishing. DATES: Effective February 24, 2012, through December 31, 2012. ADDRESSES...). Although herring is not overfished and is not experiencing overfishing, the herring annual acceptable... level that prevents overfishing. The sub-ACLs overages in 2010 did not result in overfishing, therefore...

  11. 75 FR 20550 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Specifications

    Science.gov (United States)

    2010-04-20

    ... time. Additionally, the SSC recommended that a new herring benchmark stock assessment is needed to... MSY . A new benchmark stock assessment is needed to address the inconsistency between long-term... herring stock complex is a transboundary stock and is found in both U.S and Canadian waters. As such, the...

  12. 75 FR 48874 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Specifications

    Science.gov (United States)

    2010-08-12

    ... until a new benchmark stock assessment can be conducted. They cited concern about the high level of... additional data to assess the resource as it prepares for the next benchmark stock assessment in 2012. They... role of herring as a forage species, past declines in the New England herring stock, and concern that...

  13. Outlier loci detect intraspecific biodiversity amongst spring and autumn spawning herring across local scales

    DEFF Research Database (Denmark)

    Bekkevold, Dorte; Gross, Riho; Arula, Timo

    2016-01-01

    Herring, Clupea harengus, is one of the ecologically and commercially most important species in European northern seas, where two distinct ecotypes have been described based on spawning time; spring and autumn. To date, it is unknown if these spring and autumn spawning herring constitute genetica...... of these co-occurring ecotypes to meet requirements for sustainable exploitation and ensure optimal livelihood for coastal communities....

  14. Recovery of biomolecules from marinated herring (Clupea harengus) brine using ultrafiltration through ceramic membranes

    DEFF Research Database (Denmark)

    Gringer, Nina; Hosseini, Seyed Vali; Svendsen, Tore

    2015-01-01

    Marinated herring processing brines, which are usually discarded, are rich in salt, protein, non-protein nitrogen, iron, fatty acids, antioxidant and even possess enzymatic activity. This study investigated the performance of ceramic ultrafiltration of two herring spice brines with a major focus...

  15. Prey selection by North Sea herring (Clupea harengus) with special reference to fish eggs

    NARCIS (Netherlands)

    Segers, F.H.I.D.; Dickey-Collas, M.; Rijnsdorp, A.D.

    2007-01-01

    The herring stock in the North Sea in recent years has recovered to a relatively high biomass, and here we investigate prey selection of individual North Sea herring when population numbers are high. The diet composition, and specifically pelagic fish eggs, was investigated in February 2004. Samples

  16. In situ activity of chymotrypsin in sugar-salted herring during cold storage

    DEFF Research Database (Denmark)

    Engvang, K.L.; Nielsen, Henrik Hauch

    2000-01-01

    In sifts activity of intestinal chymotrypsin in sugar-salted whole herring during cold storage was evaluated by analysing changes in the low-molecular-weight nitrogen fraction when a specific inhibitor was added. Addition of chymostatin (0.01 mM) to sugar-salted herring gave 100% inhibition...

  17. Energetic Cost of Ichthyophonus Infection in Juvenile Pacific Herring (Clupea pallasii

    Directory of Open Access Journals (Sweden)

    Johanna J. Vollenweider

    2011-01-01

    Full Text Available The energetic costs of fasting and Ichthyophonus infection were measured in juvenile Pacific herring (Clupea pallasii in a lab setting at three temperatures. Infected herring incurred significant energetic costs, the magnitude of which depended on fish condition at the time of infection (fat versus lean. Herring that were fed continually and were in relatively good condition at the time of infection (fat never stored lipid despite ad libitum feeding. In feeding herring, the energetic cost of infection was a 30% reduction in total energy content relative to controls 52 days post infection. Following food deprivation (lean condition, infection caused an initial delay in the compensatory response of herring. Thirty-one days after re-feeding, the energetic cost of infection in previously-fasted fish was a 32% reduction in total energy content relative to controls. Body composition of infected herring subsequently recovered to some degree, though infected herring never attained the same energy content as their continuously fed counterparts. Fifty-two days after re-feeding, the energetic cost of infection in previously-fasted fish was a 6% reduction in total energy content relative to controls. The greatest impacts of infection occurred in colder temperatures, suggesting Ichthyophonus-induced reductions in body condition may have greater consequences in the northern extent of herring's range, where juveniles use most of their energy reserves to survive their first winter.

  18. Energetic Cost of Ichthyophonus Infection in Juvenile Pacific Herring (Clupea pallasii).

    Science.gov (United States)

    Vollenweider, Johanna J; Gregg, Jake L; Heintz, Ron A; Hershberger, Paul K

    2011-01-01

    The energetic costs of fasting and Ichthyophonus infection were measured in juvenile Pacific herring (Clupea pallasii) in a lab setting at three temperatures. Infected herring incurred significant energetic costs, the magnitude of which depended on fish condition at the time of infection (fat versus lean). Herring that were fed continually and were in relatively good condition at the time of infection (fat) never stored lipid despite ad libitum feeding. In feeding herring, the energetic cost of infection was a 30% reduction in total energy content relative to controls 52 days post infection. Following food deprivation (lean condition), infection caused an initial delay in the compensatory response of herring. Thirty-one days after re-feeding, the energetic cost of infection in previously-fasted fish was a 32% reduction in total energy content relative to controls. Body composition of infected herring subsequently recovered to some degree, though infected herring never attained the same energy content as their continuously fed counterparts. Fifty-two days after re-feeding, the energetic cost of infection in previously-fasted fish was a 6% reduction in total energy content relative to controls. The greatest impacts of infection occurred in colder temperatures, suggesting Ichthyophonus-induced reductions in body condition may have greater consequences in the northern extent of herring's range, where juveniles use most of their energy reserves to survive their first winter.

  19. 75 FR 71731 - Notice of Availability of the Record of Decision for the Harvest of Glaucous-Winged Gull Eggs by...

    Science.gov (United States)

    2010-11-24

    ... for the Harvest of Glaucous-Winged Gull Eggs by Huna Tlingit in Glacier Bay National Park and Preserve... availability of the Record of Decision for the Harvest of Glaucous-Winged Gull Eggs by Huna Tlingit in Glacier... Impact Statement (LEIS) on the Harvest of Glaucous-Winged Gull Eggs by Huna Tlingit in Glacier Bay...

  20. Nocturnal feeding under artificial light conditions by Brown-hooded Gull (Larus maculipennis) in Puerto Madryn harbour (Chubut Province, Argentina)

    NARCIS (Netherlands)

    Leopold, M.F.; Philippart, C.J.M.; Yorio, P.

    2010-01-01

    This paper describes nocturnal, marine feeding behaviour in the Brown-hooded Gull (Larus maculipennis) in November 2009. The gulls assembled at night at the end of a long pier, running 800 m offshore into the Golfo Nuevo, at Puerto Madryn, Chubut Province, Argentina. Powerful lights predictably

  1. Pathogenecity of Ichthyophonus hoferi for laboratory-reared Pacific herring (Clupea pallasi) and its early appearance in wild Puget Sound herring

    Science.gov (United States)

    Kocan, R.; Hershberger, P.; Mehl, T.; Elder, N.; Bradley, M.; Wildermuth, D.; Stick, K.

    1999-01-01

    Laboratory-reared pathogen-free Pacific herring were exposed to pure cultures of Ichthyophonus hoferi, and reproduced the disease seen in naturally infected fish--thus fulfilling Koch's Postulates. Pathogen-free herring used in this study were reared from artificially spawned eggs incubated in filtered, UV-sterilized seawater, eliminating the variables associated with multiple infections, which are common in wild herring. Wild free-ranging herring were captured monthly from June through October by dip net from 'herring balls' located in the northern Puget Sound. I. hoferi infections were identified in these fish soon after metamorphoses, about 4 mo post-hatch. The prevalence increased from 5 to 6% in 0-yr fish to 24% in 1-yr-old fish to 50 to 70% in fish over 2 yr old, with no associated increase in mortality. The route of natural transmission to wild herring was not determined, but carnivorous fish became infected and died when they were experimentally fed tissues infected with the organism. In vitro culture of tissues was the most sensitive method for identifying both clinical and subclinical infections.

  2. Pathogenicity of Ichthyophonus hoferi for laboratory-reared Pacific herring Clupea pallasi and its early appearance in wild Puget Sound herring.

    Science.gov (United States)

    Kocan, R M; Hershberger, P; Mehl, T; Elder, N; Bradley, M; Wildermuth, D; Stick, K

    1999-01-07

    Laboratory-reared pathogen-free Pacific herring were exposed to pure cultures of Ichthyophonus hoferi, and reproduced the disease seen in naturally infected fish--thus fulfilling Koch's Postulates. Pathogen-free herring used in this study were reared from artificially spawned eggs incubated in filtered, UV-sterilized seawater, eliminating the variables associated with multiple infections, which are common in wild herring. Wild free-ranging herring were captured monthly from June through October by dip net from 'herring balls' located in the northern Puget Sound. I. hoferi infections were identified in these fish soon after metamorphoses, about 4 mo post-hatch. The prevalence increased from 5 to 6% in 0-yr fish to 24% in 1-yr-old fish to 50 to 70% in fish over 2 yr old, with no associated increase in mortality. The route of natural transmission to wild herring was not determined, but carnivorous fish became infected and died when they were experimentally fed tissues infected with the organism. In vitro culture of tissues was the most sensitive method for identifying both clinical and subclinical infections.

  3. Pathogenicity of Ichthyophonus hoferi for laboratory-reared Pacific herring Clupea pallasi and its early appearance in wild Puget Sound herring

    Science.gov (United States)

    Kocan, R.M.; Hershberger, P.; Mehl, T.; Elder, N.; Bradley, M.; Wildermuth, D.; Stick, K.

    1999-01-01

    Laboratory-reared pathogen-free Pacific herring were exposed to pure cultures of Ichthyophonus hoferi, and reproduced the disease seen in naturally infected fish - thus fulfilling Koch's Postulates. Pathogen-free herring used in this study were reared from artificially spawned eggs incubated in filtered, UV-sterilized seawater, eliminating the variables associated with multiple infections, which are common in wild herring. Wild free-ranging herring were captured monthly from June through October by dip net from 'herring balls' located in the northern Puget Sound. I. hoferi infections were identified in these fish soon after metamorphoses, about 4 mo post-hatch. The prevalence increased from 5 to 6% in 0-yr fish to 24% in 1-yr-old fish to 50 to 70% in fish over 2 yr old, with no associated increase in mortality. The route of natural transmission to wild herring was not determined, but carnivorous fish became infected and died when they were experimentally fed tissues infected with the organism. In vitro culture of tissues was the most sensitive method for identifying both clinical and subclinical infections.

  4. Complete breeding failures in ivory gull following unusual rainy storms in North Greenland

    Directory of Open Access Journals (Sweden)

    Glenn Yannic

    2014-03-01

    Full Text Available Natural catastrophic events such as heavy rainfall and windstorms may induce drastic decreases in breeding success of animal populations. We report the impacts of summer rainfalls on the reproductive success of ivory gull (Pagophila eburnea in north-east Greenland. On two occasions, at Amdrup Land in July 2009 and at Station Nord in July 2011, we observed massive ivory gull breeding failures following violent rainfall and windstorms that hit the colonies. In each colony, all of the breeding birds abandoned their eggs or chicks during the storm. Juvenile mortality was close to 100% at Amdrup Land in 2009 and 100% at Station Nord in 2011. Our results show that strong winds associated with heavy rain directly affected the reproductive success of some Arctic bird species. Such extreme weather events may become more common with climate change and represent a new potential factor affecting ivory gull breeding success in the High Arctic.

  5. Empirically based models of oceanographic and biological influences on Pacific Herring recruitment in Prince William Sound

    Science.gov (United States)

    Sewall, Fletcher; Norcross, Brenda; Mueter, Franz; Heintz, Ron

    2018-01-01

    Abundances of small pelagic fish can change dramatically over time and are difficult to forecast, partially due to variable numbers of fish that annually mature and recruit to the spawning population. Recruitment strength of age-3 Pacific Herring (Clupea pallasii) in Prince William Sound, Alaska, is estimated in an age-structured model framework as a function of spawning stock biomass via a Ricker stock-recruitment model, and forecasted using the 10-year median recruitment estimates. However, stock size has little influence on subsequent numbers of recruits. This study evaluated the usefulness of herring recruitment models that incorporate oceanographic and biological variables. Results indicated herring recruitment estimates were significantly improved by modifying the standard Ricker model to include an index of young-of-the-year (YOY) Walleye Pollock (Gadus chalcogrammus) abundance. The positive relationship between herring recruits-per-spawner and YOY pollock abundance has persisted through three decades, including the herring stock crash of the early 1990s. Including sea surface temperature, primary productivity, and additional predator or competitor abundances singly or in combination did not improve model performance. We suggest that synchrony of juvenile herring and pollock survival may be caused by increased abundance of their zooplankton prey, or high juvenile pollock abundance may promote prey switching and satiation of predators. Regardless of the mechanism, the relationship has practical application to herring recruitment forecasting, and serves as an example of incorporating ecosystem components into a stock assessment model.

  6. Infecting Pacific Herring with Ichthyophonus sp. in the laboratory

    Science.gov (United States)

    Hershberger, Paul; Hart, Lucas; Mackenzie, Ashley; Yanney, M.L.; Conway, Carla M.; Elliott, Diane G.

    2015-01-01

    The protistan parasite Ichthyophonus sp. occurs in coastal populations of Pacific Herring Clupea pallasii throughout the northeast Pacific region, but the route(s) by which these planktivorous fish become infected is unknown. Several methods for establishing Ichthyophonus infections in laboratory challenges were examined. Infections were most effectively established after intraperitoneal (IP) injections with suspended parasite isolates from culture or after repeated feedings with infected fish tissues. Among groups that were offered the infected tissues, infection prevalence was greater after multiple feedings (65%) than after a single feeding (5%). Additionally, among groups that were exposed to parasite suspensions prepared from culture isolates, infection prevalence was greater after exposure by IP injection (74%) than after exposure via gastric intubation (12%); the flushing of parasite suspensions over the gills did not lead to infections in any of the experimental fish. Although the consumption of infected fish tissues is unlikely to be the primary route of Ichthyophonus sp. transmission in wild populations of Pacific Herring, this route may contribute to abnormally high infection prevalence in areas where juveniles have access to infected offal.

  7. Infecting Pacific Herring with Ichthyophonus sp. in the Laboratory.

    Science.gov (United States)

    Hershberger, P K; Hart, L M; MacKenzie, A H; Yanney, M L; Conway, C M; Elliott, D G

    2015-12-01

    The protistan parasite Ichthyophonus sp. occurs in coastal populations of Pacific Herring Clupea pallasii throughout the northeast Pacific region, but the route(s) by which these planktivorous fish become infected is unknown. Several methods for establishing Ichthyophonus infections in laboratory challenges were examined. Infections were most effectively established after intraperitoneal (IP) injections with suspended parasite isolates from culture or after repeated feedings with infected fish tissues. Among groups that were offered the infected tissues, infection prevalence was greater after multiple feedings (65%) than after a single feeding (5%). Additionally, among groups that were exposed to parasite suspensions prepared from culture isolates, infection prevalence was greater after exposure by IP injection (74%) than after exposure via gastric intubation (12%); the flushing of parasite suspensions over the gills did not lead to infections in any of the experimental fish. Although the consumption of infected fish tissues is unlikely to be the primary route of Ichthyophonus sp. transmission in wild populations of Pacific Herring, this route may contribute to abnormally high infection prevalence in areas where juveniles have access to infected offal.

  8. Baltic Herring Fisheries Management: Stakeholder Views to Frame the Problem

    Directory of Open Access Journals (Sweden)

    Päivi Haapasaari

    2012-09-01

    Full Text Available Comprehensive problem framing that includes different perspectives is essential for holistic understanding of complex problems and as the first step in building models. We involved five stakeholders to frame the management problem of the Central Baltic herring fishery. By using the Bayesian belief networks (BBNs approach, the views of the stakeholders were built into graphical influence diagrams representing variables and their dependencies. The views of the scientists involved concentrated on biological concerns, whereas the fisher, the manager, and the representative of an environmental nongovernmental organization included markets and fishing industry influences. Management measures were considered to have a relatively small impact on the development of the herring stock; their impact on socioeconomic objectives was greater. Overall, the framings by these stakeholders propose a focus on socioeconomic issues in research and management and explicitly define management objectives, not only in biological but also in social and economic terms. We find the approach an illustrative tool to structure complex issues systematically. Such a tool can be used as a forum for discussion and for decision support that explicitly includes the views of different stakeholder groups. It enables the examination of social and biological factors in one framework and facilitates bridging the gap between social and natural sciences. A benefit of the BBN approach is that the graphical model structures can be transformed into a quantitative form by inserting probabilistic information.

  9. Reduction of garbage in the diet of nonbreeding glaucous gulls corresponding to a change in waste management

    Science.gov (United States)

    Weiser, Emily L.; Powell, Abby N.

    2011-01-01

    Glaucous gulls (Larus hyperboreus) are major predators in the Arctic and may benefit from human development. We studied use of garbage by glaucous gulls in Barrow, Alaska, in 2007, when municipal waste was disposed of in a landfill, and in 2008, when it was incinerated. In both years, diet samples from breeding adult gulls contained less garbage than those from loafing nonbreeding gulls (mostly subadults of less than four years), possibly because the breeding colony was more distant than many loafing sites from the landfills. Although breeding gull samples showed no change, garbage in regurgitated pellets and food remains of nonbreeding gulls was significantly less prevalent in 2008 than in 2007 (28% vs. 43% occurrence in diet samples), and this reduction could be explained by the switch from landfill to waste incineration. Yet garbage remained a substantial part of nonbreeding gull diet after the management change. Other aspects of waste management, such as storage prior to disposal, may also be important in limiting scavengers’ access to garbage and thus reducing the indirect impact of human development on prey species of conservation concern.

  10. Kelp gulls prey on the eyes of juvenile Cape fur seals in Namibia ...

    African Journals Online (AJOL)

    The kelp gull Larus dominicanus is an abundant and highly successful avian predator and scavenger that breeds along the coastline in the Southern Hemisphere, ranging from Antarctica to the tropics. On account of its dietary breadth, wide-ranging foraging strategies, and acclimation to modified landscapes, this species ...

  11. Effects of testosterone on growth, plumage pigmentation, and mortality in Black-headed Gull chicks

    NARCIS (Netherlands)

    Ros, A.F.H.

    In the Black-headed Gull Larus ridibundus, sibling chicks defend small territories against conspecifics with testosterone-dependent aggressive behaviour. The energetic requirements for the performance of this behaviour may trade off against the energetic requirements for growth. There are

  12. American Conference on Theoretical Chemistry Held in Gull Lake, Minnesota on July 25-31, 1987.

    Science.gov (United States)

    1988-01-01

    Texas 78712 ABSTRACT A new algorithm for self-consistent electronic structure calculations has been developed. The algorithm is a synthesis of...calculations has been developed. The algorithm is a synthesis of conventional electronic structure techniques with the pseudospectral method, a numerical...formanilide and trimethylamine represent possible associative sites of the local P anesthetics procaine and lidocaine . Dimethylphosphate monoanion, o

  13. Living on the edge: demography of the slender-billed gull in the Western Mediterranean.

    Directory of Open Access Journals (Sweden)

    Ana Sanz-Aguilar

    Full Text Available Small and peripheral populations are typically vulnerable to local extinction processes but important for the metapopulation dynamics of species. The Slender-billed gull (Chroicocephalus genei is a long-lived species breeding in unstable ephemeral coastal habitats. Their Western Mediterranean populations are relatively small and represent the edge of their global geographical distribution. At a local scale, using long-term data (14 years on annual breeding success and capture-resights of marked individuals, we estimated and compared the vital rates and evaluated the connectivity of two Spanish populations (Ebro Delta and Doñana varying in their local environmental conditions. At a metapopulation scale, we analyzed 22 years of data on breeding numbers to predict their future prospects by means of population demographic models. Local survival and breeding success of gulls from the Ebro Delta was lower than those from Doñana, which is likely the result of higher permanent emigration and/or winter mortality in the former. Gulls from the Ebro Delta wintered mostly in Mediterranean areas whereas those from Doñana did so in Atlantic coasts, where food availability is higher. Whereas adult local survival was constant, juvenile local survival showed temporal parallel variations between colonies, probably related to natal dispersal to other breeding colonies. Our results suggested that dispersal was higher at the Ebro Delta and gulls emigrating from their natal colonies settled preferentially in close patches. We found large fluctuations in breeding numbers among local populations probably related to the fact that the Slender-billed gull is a species adapted to unstable and unpredictable habitats with high abilities to disperse between suitable patches depending on environmental stochastic conditions during breeding.

  14. The Gordian knot: managing herring (Clupea harengus) bridging across populations, fishery units, management areas, and politics

    DEFF Research Database (Denmark)

    Worsøe Clausen, Lotte; Mosegaard, Henrik; Berg, Casper Willestofte

    2012-01-01

    –24) and the North Sea (Division IIIa) by various EU—and in the latter case also non‐EU—fishing fleets. For the two separate management areas, TACs are set at different times in the yearly TACsetting process by the EU and negotiating counties, which often result in conflicts over quota allocations among different......The management of western Baltic spring spawning (WBSS) herring is challenged by the highly complex stock structure with a temporal and geographical distribution leading to conflicting interests among different stakeholder groups. The stock is exploited in the Baltic Sea (Subdivisions 22...... management units. The WBSS herring stock spawns in the western Baltic Sea and migrates into the Kattegat and Skagerrak areas, where it mixes with North Sea autumn spawning (NSAS) herring. Recent development of otolith shape analysis has enabled a high‐resolution separation of herring stocks in these waters...

  15. Recurrent mass mortalities of the blueback herring, Alosa aestivalis, in the lower Connecticut River

    International Nuclear Information System (INIS)

    Moss, S.A.; Leggett, W.C.; Boyd, W.A.

    1976-01-01

    The authors studied 5 mass mortalities of blueback herring, Alosa aestivalis between 1965 and 1971. The reach of the Connecticut River in which the mortalities were observed includes the region thermally influenced by cooling water effluents from the Connecticut Yankee Atomic Power Plant. This warm water effluent has not been related to catastrophic blueback herring mortalities to the present time. The mortalities observed in 1965, 1966, and 1967 occurred before the plant became operational. The years of no abnormal mortalities, 1968, 1969, and 1970 coincided with periods of near-maximum generating output by this power plant. Only in June, 1971, did power plant operation coincide with a mass mortality of herring. Nevertheless, the occurrence of herring mortalities in four years out of seven observed suggests that further deterioration of water quality in the Connecticut River may threaten the continued spawning success of this fish. 9 references, 4 figures, 4 tables

  16. AFSC/ABL: Southeast and Prince William Sound, Alaska Herring Microsatellite data, 2007-2008

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Herring is one of the most energy-rich fish in the Alaskan ecosystem, and when populations struggle over time, such as the Lynn Canal population, there is management...

  17. Chasing red herrings: Memory of distractors causes fixation in creative problem solving.

    Science.gov (United States)

    Beda, Zsolt; Smith, Steven M

    2018-03-07

    Two experiments tested the red herring retrieval hypothesis, which states that fixation in creative problem solving is worse when memory for red herrings (i.e., inappropriate or incorrect solutions) is strengthened. In Experiment 1, when associations between Remote Associates Test (RAT) problem words (e.g., COTTAGE, SWISS, CAKE) and related red herring words (e.g., hut, chocolate, icing) were strengthened via repetition, an encoding variable, fixation was found to increase. In Experiment 2, when associations were formed between RAT problem contexts and red herrings, then subsequent reinstatement of problem contexts during RAT problem solving trials (as compared with showing new contexts) also worsened fixation effects. Our results add to the increasing body of research that connects memory with creative problem solving, and they suggest possible ways for overcoming fixation effects.

  18. Addressing socio-cultural values in the use and management of Baltic herring

    DEFF Research Database (Denmark)

    Ignatius, Suvi; Haapasaari, Päivi Elisabet

    2016-01-01

    , and is mainly used for animal feed and fishmeal and oil. Harmful dioxins in Baltic herring have been offered as an explanation for its reduced human consumption. We argue that dioxins are only part of the explanation while sociocultural values also influence the use and management of the fish resource....... By applying the justification theory of Boltanski and Thévenot to expert workshop discussions and a literature review, we investigate (1) what values people in Sweden, Finland, Denmark and Estonia associate with Baltic herring; and (2) which values determine the way the fish resource is used. Our study...... indicates that management decisions related to Baltic herring are predominantly guided by economic values and industrial efficiency. Profit optimisation in the fishery together with the image problem that Baltic herring suffers from, seem to have contributed to the devaluation of this fish species as food...

  19. Properties of protein powders from arrowtooth flounder (Atheresthes stomias) and herring (Clupea harengus) byproducts.

    Science.gov (United States)

    Sathivel, Subramaniam; Bechtel, Peter J; Babbitt, Jerry; Prinyawiwatkul, Witoon; Negulescu, Ioan I; Reppond, Kermit D

    2004-08-11

    Functional, nutritional, and thermal properties of freeze-dried protein powders (FPP) from whole herring (WHP), herring body (HBP), herring head (HHP), herring gonad (HGP), and arrowtooth flounder fillets (AFP) were evaluated. The FPP samples have desirable nutritional and functional properties and contained 63-81.4% protein. All FPP samples had desirable essential amino acid profiles and mineral contents. The emulsifying and fat adsorption capacities of all FPP samples were higher than those of soy protein concentrate. The emulsifying stability of WHP was lower than that of egg albumin but greater than that of soy protein concentrate. Thermal stability of the FPP samples is in the following order: HGP > HBP > WHP > HHP > AFP.

  20. LANDSAT menhaden and thread herring resources investigation. [Gulf of Mexico

    Science.gov (United States)

    Kemmerer, A. J. (Principal Investigator); Brucks, J. T.; Butler, J. A.; Faller, K. H.; Holley, H. J.; Leming, T. D.; Savastano, K. J.; Vanselous, T. M.

    1977-01-01

    The author has identified the following significant results. The relationship between the distribution of menhaden and selected oceanographic parameters (water color, turbidity, and possibly chlorophyll concentrations) was established. Similar relationships for thread herring were not established nor were relationships relating to the abundance of either species. Use of aircraft and LANDSAT remote sensing instruments to measure or infer a set of basic oceanographic parameters was evaluated. Parameters which could be accurately inferred included surface water temperature, salinity, and color. Water turbidity (Secchi disk) was evaluated as marginally inferrable from the LANDSAT MSS data and chlorophyll-a concentrations as less than marginal. These evaluations considered the parameters only as experienced in the two test areas using available sensors and statistical techniques.

  1. Incorporating stakeholders' knowledge to stock assessment: Central Baltic herring

    DEFF Research Database (Denmark)

    Mäntyniemi, Samu; Haapasaari, Päivi Elisabet; Kuikka, Sakari

    2013-01-01

    We present a method by which the knowledge of stakeholders can be taken into account in stock assessment. The approach consists of a structured interview process followed by quantitative modelling of the answers. The outcome is a set of probability models, each describing the views of different...... stakeholders. Individual models are then merged to a large model by applying the techniques of Bayesian model averaging, and this model is conditioned on stock assessment data. As a result, the viewsofinterviewedstakeholdershavebeentakenintoaccountandweighedbasedonhowwelltheirviewsaresupportedbythe observed...... data. We applied this method to the Baltic Sea herring (Clupea harengus) stock assessment by interviewing six stakeholders and conditioning the resulting models on stock assessment data provided by the International Council for the Exploration of the Sea....

  2. Organohalogen pollutants in herring from the northern Baltic Sea: Concentrations, congener profiles and explanatory factors

    International Nuclear Information System (INIS)

    Koistinen, Jaana; Kiviranta, Hannu; Ruokojaervi, Paeivi; Parmanne, Raimo; Verta, Matti; Hallikainen, Anja; Vartiainen, Terttu

    2008-01-01

    Organohalogen contaminants were investigated in Baltic herring caught from three catchment areas in the Baltic Sea, off the coasts of Finland. Pools of both small and large herring were analysed for polychlorinated biphenyls (PCB), dibenzo-p-dioxins, dibenzofurans, naphthalenes, camphenes (toxaphene), polybrominated diphenyl ethers and the pesticide DDT and its metabolites. PCB concentrations per fresh weight in small herring were at the same level in all catchment areas, i.e. the Bothnian Bay, the Bothnian Sea and the Gulf of Finland, revealing no hot spots and reflecting most likely long term emissions and atmospheric deposition. Differences in the levels and/or congener profiles of other contaminants between catchment areas may be explained by point sources. Similar concentrations in small and large herring in the Gulf of Finland were possibly due to their common nutrition. In the other areas, differences between small and large herring most likely reflected their different food sources. - Sources of pollutants are reflected in levels and congener profiles of pollutants in Baltic herring

  3. The Adopt-a-Herring program as a fisheries conservation tool

    Science.gov (United States)

    Frank, Holly J.; Mather, Martha E.; Muth, Robert M.; Pautzke, Sarah M.; Smith, Joseph M.; Finn, John T.

    2009-01-01

    Successful conservation depends on a scientifically literate public. We developed the adopt-a-Herring program to educate nonscientists about fisheries and watershed restoration. this interactive educational and outreach project encouraged coastal residents to be involved in local watershed restoration. In the northeastern United States, river herring (Alosa spp.) are an important component of many coastal watersheds and often are the object of conservation efforts. In order to understand river herring spawning behavior and to improve the effectiveness of restoration efforts, our research tracked these fish via radiotelemetry in the Ipswich River, Massachusetts. In our adopt-a-Herring Program, participating stakeholder organizations adopted and named individual tagged river herring and followed their movements online. We also made information available to our adopters on our larger research goals, the mission and activities of other research and management agencies, examples of human actions that adversely affect watersheds, and opportunities for proactive conservation. Research results were communicated to adopters through our project web page and end-of-the-season summary presentations. Both tools cultivated a personal interest in river herring, stimulated discussion about fisheries and watershed restoration, educated participants about the goals and methods of scientists in general, and initiated critical thinking about human activities that advance or impede sustainability.

  4. Demographics and chronology installation nests of Yellow-legged Gull (Larus ridibundus) in the region of Jijel (Algeria)

    International Nuclear Information System (INIS)

    Bougaham, A. F.; Moulai, R.

    2013-01-01

    During the 2007 breeding season, the population of Yellow-legged Gull in the region of Jijel has experienced a growth of 4,06% from 1978. The annual average increaseλ observed is 1,02 for Grand Cavallo Island and 1,10 for Petit Cavallo Island. The mean density of Yellow-legged Gull for one coastal kilometer is 18, 4 pairs. Nests installation of Yellow-legged Gull is early and staggered at the traditional nesting sites, namely Grand and Petit Cavallo Islands. In contrast, it is quite late and synchronous at Grand Cavallo and the cliffs of Pointe Thamakrent. Yellow-legged Gulls in the region of Jijel have a large growing population, including the colonization of new nesting sites. (author)

  5. Regional variation in the intensity of humpback whale predation on Pacific herring in the Gulf of Alaska

    Science.gov (United States)

    Moran, J. R.; Heintz, R. A.; Straley, J. M.; Vollenweider, J. J.

    2018-01-01

    We modeled the biomass of Pacific herring (Clupea pallasii) consumed by humpback whales (Megaptera novaeangliae) to determine if whales are preventing the recovery of some herring populations in the Gulf of Alaska. We estimated consumption, by whales, of two depressed (Lynn Canal, Prince William Sound) and one robust (Sitka Sound) herring populations during fall/winter of 2007-2008 and 2008-2009. Consumption estimates relied on observations of whale abundance, prey selection, and herring energy content along with published data on whale size and metabolic rate. Herring biomass removed by whales was compared with independent estimates of herring abundance to assess the impact of predation on each population. Whales removed a greater proportion of the total biomass of herring available in Lynn Canal and Prince William Sound than in Sitka Sound. Biomass removals were greatest in Prince William Sound where we observed the largest number of whales foraging on herring. The biomass of herring consumed in Prince William Sound approximated the biomass lost to natural mortality over winter as projected by age-structured stock assessments. Though whales also focused their foraging on herring during the fall in Lynn Canal, whales were less abundant resulting in lower estimated consumption rates. Whales were more abundant in Sitka Sound than in Lynn Canal but foraged predominately on euphausiids. Herring abundance was greater in Sitka Sound, further reducing the overall impact on the herring population. These data indicate that the focused predation in Prince William Sound can exert top-down controlling pressure, but whale populations are not a ubiquitous constraint on forage fish productivity in the Gulf of Alaska at this time.

  6. Experimental infection of highly pathogenic avian influenza virus H5N1 in black-headed gulls (Chroicocephalus ridibundus)

    OpenAIRE

    Ramis , Antonio; van Amerongen , Geert; van de Bildt , Marco; Leijten , Loneke; Vanderstichel , Raphael; Osterhaus , Albert; Kuiken , Thijs

    2014-01-01

    Historically, highly pathogenic avian influenza viruses (HPAIV) rarely resulted in infection or clinical disease in wild birds. However, since 2002, disease and mortality from natural HPAIV H5N1 infection have been observed in wild birds including gulls. We performed an experimental HPAIV H5N1 infection of black-headed gulls (Chroicocephalus ridibundus) to determine their susceptibility to infection and disease from this virus, pattern of viral shedding, clinical signs, pathological changes a...

  7. Environmental pollutants in endangered vs. increasing subspecies of the lesser black-backed gull on the Norwegian Coast

    International Nuclear Information System (INIS)

    Bustnes, Jan Ove; Helberg, Morten; Strann, Karl-Birger; Skaare, Janneche Utne

    2006-01-01

    Organochlorine (OC) residues were measured in eggs and blood of different subspecies of the lesser black-backed gull, Larus fuscus, on the Norwegian coast: a) increasing L. f. intermedius in the North Sea; b) endangered L. f. fuscus near the Arctic Circle; c) L. f. fuscus and greyish-mantled gulls, with a L. f. intermedius appearance, in the Barents Sea region. The dominating OCs in lesser black-backed gulls were polychlorinated biphenyls (PCB) and p,p'-dichlorodiphenyldichloroethylene (DDE). DDE and β-hexachlorocyclohexane (β-HCH) residues were higher in L. f. fuscus compared to L. f. intermedius and greyish-mantled birds in the Barents Sea region. In the latter area, blood residues of PCB and DDE in lesser black-backed gulls were as high as in great black-backed gulls, Larus marinus, while in the other regions they were lower. The higher DDE residues in endangered L. f. fuscus compared to increasing L. f. intermedius and greyish-mantled birds, which are invading northern Norway, suggest that OCs may have played a role in the population decline of L. f. fuscus, possibly in combination with nutrient stress. - DDE and β-HCH residues were higher in an endangered compared to an increasing subspecies of lesser black-backed gulls in Norway

  8. Seasonal variation in the levels of organohalogen compounds in herring (Clupea harengus) from the Norwegian Sea.

    Science.gov (United States)

    Frantzen, Sylvia; Måge, Amund; Iversen, Svein Arnholt; Julshamn, Kåre

    2011-09-01

    The Norwegian spring spawning (NSS) herring is an ecologically important fish stock in the Norwegian Sea, and with a catch volume exceeding one million tons a year it is also economically important and a valuable food source. In order to provide a baseline of the levels of contaminants in this fish stock, the levels of organohalogen compounds were determined in 800 individual herring sampled at 29 positions in the Norwegian Sea and off the coast of Norway. Due to seasonal migration, the herring were sampled where they were located during the different seasons. Concentrations of dioxins and dioxin-like PCBs, non-dioxin-like PCBs (PCB(7)) and PBDEs were determined in fillet samples of individual herring, and found to be relatively low, with means (min-max) of 0.77 (0.24-3.5) ng TEQ kg(-1) wet weight (ww), 5.0 (1.4-24) μg kg(-1) ww and 0.47 (0.091-3.1) μg kg(-1) ww, respectively. The concentrations varied throughout the year due to the feeding- and spawning cycle: Starved, pre-spawning herring caught off the Norwegian coast in January-February had the highest levels and those caught in the Norwegian Sea in April-June, after further starvation and spawning, had the lowest levels. These results show that the concentrations of organohalogen compounds in NSS herring are relatively low and closely tied to their physiological condition, and that in the future regular monitoring of NSS herring should be made in the spawning areas off the Norwegian coast in late winter. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. California gull chicks raised near colony edges have elevated stress levels

    Science.gov (United States)

    Herring, Garth; Ackerman, Joshua T.

    2011-01-01

    Coloniality in nesting birds represents an important life history strategy for maximizing reproductive success. Birds nesting near the edge of colonies tend to have lower reproductive success than individuals nesting near colony centers, and offspring of edge-nesting parents may be impaired relative to those of central-nesting parents. We used fecal corticosterone metabolites in California gull chicks (Larus californicus) to examine whether colony size or location within the colony influenced a chick's physiological condition. We found that chicks being raised near colony edges had higher fecal corticosterone metabolite concentrations than chicks raised near colony centers, but that colony size (ranging from 150 to 11,554 nests) had no influence on fecal corticosterone levels. Fecal corticosterone metabolite concentrations also increased with chick age. Our results suggest that similarly aged California gull chicks raised near colony edges may be more physiologically stressed, as indicated by corticosterone metabolites, than chicks raised near colony centers.

  10. Diversity and abundance of water birds in a subarctic lake during three decades

    Directory of Open Access Journals (Sweden)

    Anders Klemetsen

    2013-12-01

    Full Text Available The numbers of divers, ducks, gulls, terns and waders in the 15 km2 oligotrophic lake Takvatn, North Norway were estimated six times during 1983-2012. Systematic mapping surveys were done by boat within the first week after ice-break in June. Twenty-one species were observed over the years and 12 were regarded as breeding on the lake. Red-breasted merganser Mergus serrator was the dominant diving bird, with estimated minimum number of pairs varying from 15 to 39 among years. Black-throated diver Gavia arctica (1-3 pairs, tufted duck Aythya fuligula (2-15 pairs and common scoter Melanitta nigra (1-5 pairs bred regularly, while velvet scoter Melanitta fusca (1-2 and goldeneye Bucephala clangula (2-4 were found in some years and mallard Anas platyrhynchos (1 pair and wigeon Anas penelope (1 pair in one year. Common gull Larus canus (6-30 pairs and arctic tern Sterna paradisaea (2-35 pairs bred in all years. Common sandpiper Tringa hypoleucos (3-9 pairs and redshank Tringa totanus (1-4 pairs were regular waders. Density variations of mergansers, gulls and terns are possibly related to density variations of three-spined sticklebacks Gasterosteus aculeatus, their dominant fish prey. The water birds are important links in the food web of the lake.

  11. Effects of gull predation and weather on survival of emperor goose goslings

    Science.gov (United States)

    Schmutz, Joel A.; Manly, Bryan F.J.; Dau, Christian P.

    2001-01-01

    Numbers of emperor geese (Chen canagica) have remained depressed since the mid-1980s. Despite increases in glaucous gulls (Larus hyperboreus), a primary predator of goslings, little information existed to assess whether recent patterns of gosling survival have been a major factor affecting population dynamics. We used observations of known families of emperor geese to estimate rates of gosling survival during 1993-96 on the Yukon-Kuskokwim Delta, Alaska. Survival of goslings to 30 days of age varied among years from 0.332 during 1994 to 0.708 during 1995. Survival was lowest during 1993-94, which corresponded with the years of highest frequency of disturbance of goose broods by glaucous gulls. Rainfall during early brood rearing was much higher in 1994 than other years, and this corresponded to low survival among goslings ≤5 days of age. Numbers of juveniles in families during fall staging were negatively related to rainfall during early brood rearing (n = 23 yr). Although there are no data to assess whether gosling survival in emperor geese has declined from some previous level, current survival rates of emperor goose goslings are as high as or higher than those observed in other goose species that are rapidly increasing. A proposed reduction of glaucous gull numbers by managers may not be the most effective means for increasing population growth in emperor geese.

  12. Dioxins and dl-PCBs in gull eggs from Spanish Natural Parks (2010-2013).

    Science.gov (United States)

    Morales, Laura; Gene'rosa Martrat, Ma; Parera, Jordi; Bertolero, Albert; Ábalos, Manuela; Santos, Francisco Javier; Lacorte, Silvia; Abad, Esteban

    2016-04-15

    The aim of this study was to evaluate the presence and distribution of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and biphenyls (PCBs), concretely those so-called as dioxin-like PCBs, in yellow-legged gull eggs (Larus michahellis) collected from five Natural Parks (some of them National Parks) in Spain during the period 2010-2013. PCDD/Fs and dl-PCBs were detected in all the samples. Due to the proximity to important urban and industrial areas higher concentrations were determined in colonies located in the Northern Mediterranean coast than those found in the Southern Mediterranean or Atlantic colonies where a softer anthropogenic impact occurs. Mean ∑PCDD/F concentrations ranged from 49 to 223pg/g lipid weight (lw) and ∑dl-PCB concentrations varied from 146 to 911ng/g lw. In the Natural Park of the Ebro Delta (Northern Mediterranean coast) two gull species share habitat: yellow-legged and Audouin gull (Larus audouinii). Eggs from both species were collected and PCDD/F and dl-PCB levels compared. The species that feeds exclusively on pelagic fish (L. audouinii) had significantly higher PCDD/F and dl-PCB levels than the scavenger L. michahellis, pointing out the diet-dependent differences in the accumulation of persistent organic pollutants between similar cohabitant breeding species. Finally, mean TEQ values were in general below those considered as critical for toxicological effects in birds. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Anthropogenic debris in the nests of kelp gulls in South Africa.

    Science.gov (United States)

    Witteveen, Minke; Brown, Mark; Ryan, Peter G

    2017-01-30

    Anthropogenic debris results in detrimental interactions with many marine species. Several seabirds include debris items in their nests, which can lead to entanglement of chicks and adults, resulting in injury or death. Anthropogenic debris was found in 4-67% of kelp gull Larus dominicanus nests in seven colonies in the Western Cape, South Africa. Nests contained two types of litter: items included in the nest structure during construction (mainly ropes and straps), and regurgitated items (mainly bags and food wrappers) that probably accumulate primarily during the chick-rearing period. Debris used in nest construction was more likely to injure gulls, and was found mainly at coastal sites where there was little natural vegetation for construction. Distance to the nearest urban waste landfill significantly affected the occurrence of debris items in nests, especially dietary-derived items. The amount of debris in kelp gull nests highlights the need for improved debris management in South Africa. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Persistent organic pollutants, heavy metals and parasites in the glaucous gull (Larus hyperboreus) on Spitsbergen

    Energy Technology Data Exchange (ETDEWEB)

    Sagerup, Kjetil, E-mail: kjetil.sagerup@uit.n [Tromso University Museum, NO-9037 Tromso (Norway); Savinov, Vladimir; Savinova, Tatiana [Akvaplan-niva, Polar Environmental Centre, NO-9296 Tromso (Norway); Kuklin, Vadim [Murmansk Marine Biological Institute, Kola Scientific Centre, Russian Academy of Sciences, Murmansk (Russian Federation); Muir, Derek C.G. [Aquatic Ecosystem Protection Research Division, Environment Canada, Burlington ON L7R 4A6 (Canada); Gabrielsen, Geir W. [Norwegian Polar Institute, Polar Environmental Centre, NO-9296 Tromso (Norway)

    2009-08-15

    The prediction of a higher parasite infection as a consequence of an impaired immune system with increasing persistent organic pollution (POP) and heavy metal levels were investigated in adult glaucous gull (Larus hyperboreus) from Svalbard. The levels of chlorinated pesticides, polychlorinated biphenyls (PCBs), toxaphenes and polybrominated diphenyl ethers (PBDEs) were measured in liver. Cupper, cadmium, lead, mercury, selenium and zinc were measured in kidney samples. An elevated ratio of PCB-118 was found, suggesting that local contamination from the settlement was detectable in the glaucous gull. Eight cestodes, four nematodes, two acanthocephalan and three trematode helminth species were found in the intestine. A positive correlation was found between cestode intensities and selenium levels and between acanthocephalan intensities and mercury levels. No correlation was found between parasite intensities and POP concentrations. It is concluded that the contaminant levels found in glaucous gulls do not cause immune suppression severe enough to affect parasite intensity. - Consistent relationships between contaminant level and parasite intensity, as an immunotoxic endpoint unit, were not found in the present study.

  15. Persistent organic pollutants, heavy metals and parasites in the glaucous gull (Larus hyperboreus) on Spitsbergen

    International Nuclear Information System (INIS)

    Sagerup, Kjetil; Savinov, Vladimir; Savinova, Tatiana; Kuklin, Vadim; Muir, Derek C.G.; Gabrielsen, Geir W.

    2009-01-01

    The prediction of a higher parasite infection as a consequence of an impaired immune system with increasing persistent organic pollution (POP) and heavy metal levels were investigated in adult glaucous gull (Larus hyperboreus) from Svalbard. The levels of chlorinated pesticides, polychlorinated biphenyls (PCBs), toxaphenes and polybrominated diphenyl ethers (PBDEs) were measured in liver. Cupper, cadmium, lead, mercury, selenium and zinc were measured in kidney samples. An elevated ratio of PCB-118 was found, suggesting that local contamination from the settlement was detectable in the glaucous gull. Eight cestodes, four nematodes, two acanthocephalan and three trematode helminth species were found in the intestine. A positive correlation was found between cestode intensities and selenium levels and between acanthocephalan intensities and mercury levels. No correlation was found between parasite intensities and POP concentrations. It is concluded that the contaminant levels found in glaucous gulls do not cause immune suppression severe enough to affect parasite intensity. - Consistent relationships between contaminant level and parasite intensity, as an immunotoxic endpoint unit, were not found in the present study.

  16. Novel species interactions: American black bears respond to Pacific herring spawn.

    Science.gov (United States)

    Fox, Caroline Hazel; Paquet, Paul Charles; Reimchen, Thomas Edward

    2015-05-26

    In addition to the decline and extinction of the world's species, the decline and eventual loss of species interactions is one of the major consequences of the biodiversity crisis. On the Pacific coast of North America, diminished runs of salmon (Oncorhynchus spp.) drive numerous marine-terrestrial interactions, many of which have been intensively studied, but marine-terrestrial interactions driven by other species remain relatively unknown. Bears (Ursus spp.) are major vectors of salmon into terrestrial ecosystems, but their participation in other cross-ecosystem interactions is similarly poorly described. Pacific herring (Clupea pallasii), a migratory forage fish in coastal marine ecosystems of the North Pacific Ocean and the dominant forage fish in British Columbia (BC), spawn in nearshore subtidal and intertidal zones. Spawn resources (eggs, milt, and spawning adults) at these events are available to coastal predators and scavengers, including terrestrial species. In this study, we investigated the interaction between American black bears (Ursus americanus) and Pacific herring at spawn events in Quatsino Sound, BC, Canada. Using remote cameras to monitor bear activity (1,467 camera days, 29 sites, years 2010-2012) in supratidal and intertidal zones and a machine learning approach, we determined that the quantity of Pacific herring eggs in supratidal and intertidal zones was a leading predictor of black bear activity, with bears positively responding to increasing herring egg masses. Other important predictors included day of the year and Talitrid amphipod (Traskorchestia spp.) mass. A complementary analysis of black bear scats indicated that Pacific herring egg mass was the highest ranked predictor of egg consumption by bears. Pacific herring eggs constituted a substantial yet variable component of the early springtime diet of black bears in Quatsino Sound (frequency of occurrence 0-34%; estimated dietary content 0-63%). Other major dietary items included

  17. Outlier Loci Detect Intraspecific Biodiversity amongst Spring and Autumn Spawning Herring across Local Scales.

    Directory of Open Access Journals (Sweden)

    Dorte Bekkevold

    Full Text Available Herring, Clupea harengus, is one of the ecologically and commercially most important species in European northern seas, where two distinct ecotypes have been described based on spawning time; spring and autumn. To date, it is unknown if these spring and autumn spawning herring constitute genetically distinct units. We assessed levels of genetic divergence between spring and autumn spawning herring in the Baltic Sea using two types of DNA markers, microsatellites and Single Nucleotide Polymorphisms, and compared the results with data for autumn spawning North Sea herring. Temporally replicated analyses reveal clear genetic differences between ecotypes and hence support reproductive isolation. Loci showing non-neutral behaviour, so-called outlier loci, show convergence between autumn spawning herring from demographically disjoint populations, potentially reflecting selective processes associated with autumn spawning ecotypes. The abundance and exploitation of the two ecotypes have varied strongly over space and time in the Baltic Sea, where autumn spawners have faced strong depression for decades. The results therefore have practical implications by highlighting the need for specific management of these co-occurring ecotypes to meet requirements for sustainable exploitation and ensure optimal livelihood for coastal communities.

  18. Latitudinal Gradient in Otolith Shape among Local Populations of Atlantic Herring (Clupea harengus L.) in Norway.

    Science.gov (United States)

    Libungan, Lísa Anne; Slotte, Aril; Husebø, Åse; Godiksen, Jane A; Pálsson, Snæbjörn

    2015-01-01

    Otolith shape analysis of Atlantic herring (Clupea harengus) in Norwegian waters shows significant differentiation among fjords and a latitudinal gradient along the coast where neighbouring populations are more similar to each other than to those sampled at larger distances. The otolith shape was obtained using quantitative shape analysis, the outlines were transformed with Wavelet and analysed with multivariate methods. The observed morphological differences are likely to reflect environmental differences but indicate low dispersal among the local herring populations. Otolith shape variation suggests also limited exchange between the local populations and their oceanic counterparts, which could be due to differences in spawning behaviour. Herring from the most northerly location (69°N) in Balsfjord, which is genetically more similar to Pacific herring (Clupea pallasii), differed in otolith shape from all the other populations. Our results suggest that the semi-enclosed systems, where the local populations live and breed, are efficient barriers for dispersal. Otolith shape can thus serve as a marker to identify the origin of herring along the coast of Norway.

  19. Predation on larval Atlantic herring (Clupea harengus) in inshore waters of the Baltic Sea

    Science.gov (United States)

    Kotterba, Paul; Moll, Dorothee; von Nordheim, Lena; Peck, Myron A.; Oesterwind, Daniel; Polte, Patrick

    2017-11-01

    In fishery science, early life-stage survival and development are regarded as major factors driving the population dynamics of marine fishes. During the last century, the main research focus has been on the spatio-temporal match of larval fish and appropriate food (bottom-up processes). However, these field studies are often criticised for their limited capability to disentangle their results from mortality caused by predation since these top-down mechanisms are rarely studied. We examined the predation on herring (Clupea harengus) larvae in a Baltic inshore lagoon by investigating the spatio-temporal overlap of larval herring and their potential predators such as the dominant threespine stickleback (Gasterosteus aculeatus) in distinct habitats (sublittoral and littoral areas) using a set of different gears and sampling techniques. Despite significant spatial and temporal predator-prey overlap, stomach analyses suggested that very few larvae were consumed by sticklebacks, even if projected to the entire study area and season. Other well-known predators of clupeid larvae such as gelatinous plankton occur later in the year after young herring have migrated out of the system. The observed predation on herring larvae was much less than expected and appears being a minor factor in determining herring reproduction success in our study area, particularly if compared to other causes of mortality such as egg predation. Providing a relatively good shelter from predation might be a key element making transitional waters valuable nursery grounds for the offspring of migrating marine fish species.

  20. Herring parasite and tissue alterations following the Exxon Valdez oil spill

    International Nuclear Information System (INIS)

    Moles, A.D.; Rice, S.D.; Okihiro, M.S.

    1993-01-01

    The authors examined the intensity and prevalence of larval nematodes (Anisakis simplex) and alterations in selected tissues of spawning Pacific herring (Clupea harengus pallasi) exposed to crude oil, in the laboratory under controlled conditions and in Prince William Sound 14 days after the Exxon Valdez oil spill. In the laboratory, intensity and prevalence of nematodes in the body cavities of herring exposed to the water-soluble fraction of oil declined when exposed to doses above 1.2 mg/L total aromatics. In Prince William Sound, nematodes were rare in spawning herring from oiled sites and abundant among herring from areas outside the spill. Oil exposure apparently induced the nematodes to migrate from the body cavity to the body wall with the lower intensity reflecting a change in parasite location. A coccidian, Eimeria clupearum, was found in greater numbers in oil-exposed herring. To verify exposure effects and to link parasite and tissue alteration with oil exposure, histological examination was used. Liver coagulative necrosis indicated hepatotoxic exposure. Necrosis was followed by macrophage aggregation in the resolution phase. The laboratory exposures allowed confirmation of oil exposure in Prince William Sound and permitted analysis of effects on two internal parasites

  1. Feasibility of Acoustic Remote Sensing of Large Herring Shoals and Seafloor by Baleen Whales

    Directory of Open Access Journals (Sweden)

    Dong Hoon Yi

    2016-08-01

    Full Text Available Recent research has found a high spatial and temporal correlation between certain baleen whale vocalizations and peak herring spawning processes in the Gulf of Maine. These vocalizations are apparently related to feeding activities with suggested functions that include communication, prey manipulation, and echolocation. Here, the feasibility of the echolocation function is investigated. Physical limitations on the ability to detect large herring shoals and the seafloor by acoustic remote sensing are determined with ocean acoustic propagation, scattering, and statistical theories given baleen whale auditory parameters. Detection is found to be highly dependent on ambient noise conditions, herring shoal distributions, baleen whale time-frequency vocalization spectra, and geophysical parameters of the ocean waveguide. Detections of large herring shoals are found to be physically feasible in common Gulf of Maine herring spawning scenarios at up to 10 ± 6 km in range for humpback parameters and 1 ± 1 km for minke parameters but not for blue and fin parameters even at zero horizontal range. Detections of the seafloor are found to be feasible up to 2 ± 1 km for blue and humpback parameters and roughly 1 km for fin and minke parameters, suggesting that the whales share a common acoustic sensation of rudimentary features of the geophysical environment.

  2. Latitudinal Gradient in Otolith Shape among Local Populations of Atlantic Herring (Clupea harengus L.) in Norway

    Science.gov (United States)

    Libungan, Lísa Anne; Slotte, Aril; Husebø, Åse; Godiksen, Jane A.; Pálsson, Snæbjörn

    2015-01-01

    Otolith shape analysis of Atlantic herring (Clupea harengus) in Norwegian waters shows significant differentiation among fjords and a latitudinal gradient along the coast where neighbouring populations are more similar to each other than to those sampled at larger distances. The otolith shape was obtained using quantitative shape analysis, the outlines were transformed with Wavelet and analysed with multivariate methods. The observed morphological differences are likely to reflect environmental differences but indicate low dispersal among the local herring populations. Otolith shape variation suggests also limited exchange between the local populations and their oceanic counterparts, which could be due to differences in spawning behaviour. Herring from the most northerly location (69°N) in Balsfjord, which is genetically more similar to Pacific herring (Clupea pallasii), differed in otolith shape from all the other populations. Our results suggest that the semi-enclosed systems, where the local populations live and breed, are efficient barriers for dispersal. Otolith shape can thus serve as a marker to identify the origin of herring along the coast of Norway. PMID:26101885

  3. Otolith shape: a population marker for Atlantic herring Clupea harengus.

    Science.gov (United States)

    Libungan, L A; Óskarsson, G J; Slotte, A; Jacobsen, J A; Pálsson, S

    2015-04-01

    Otolith shape variation of seven Atlantic herring Clupea harengus populations from Canada, the Faroe Islands, Iceland, Ireland, Norway and Scotland, U.K., covering a large area of the species' distribution, was studied in order to see if otolith shape can be used to discriminate between populations. The otolith shape was obtained using quantitative shape analysis, transformed with Wavelet and analysed with multivariate methods. Significant differences were detected among the seven populations, which could be traced to three morphological structures in the otoliths. The differentiation in otolith shape between populations was not only correlated with their spawning time, indicating a strong environmental effect, but could also be due to differing life-history strategies. A model based on the shape differences discriminates with 94% accuracy between Icelandic summer spawners and Norwegian spring spawners, which are known to mix at feeding grounds. This study shows that otolith shape could become an accurate marker for C. harengus population discrimination. © 2015 The Fisheries Society of the British Isles.

  4. Spatially explicit estimates of stock sizes, structure and biomass of herring and blue whiting, and catch data of bluefin tuna

    DEFF Research Database (Denmark)

    Huse, G.; MacKenzie, B. R.; Trenkel, V.

    2015-01-01

    The North Atlantic is a productive marine region which has supported important commercial fisheries for centuries. Many of these fisheries have exploited the pelagic species, including herring, blue whiting and tuna. Here we present data on the distribution of herring and blue whiting based on th...

  5. Larval growth and drift pattern and the separation of herring spawning groups in the North Sea

    DEFF Research Database (Denmark)

    Munk, Peter; Christensen, Villy

    1990-01-01

    Data from two internationally co-ordinated survey programmes are used in an attempt to display the events in the early life that took place during the 'recovery period' of the North Sea herring stock, 1979-1986. During the period, an increasing importance of the spawning grounds off Buchan and off...... Yorkshire is evident from distributions of newly hatched herring larvae. The dramatic changes in relative importance of spawning grounds are traced in the data on both late larvae (6 months old) and juveniles (18 months old). The onset of extended spawning off Buchan and off Yorkshire was followed...... in the relative contributions from spawning grounds apparently influence the overall spatial distribution as well as size composition of larval and juvenile North Sea herring. The findings indicate that groups of larvae retain, to a large extent, separate distributions until metamorphosis, and point to larval...

  6. Stock structure of Atlantic herring Clupea harengus in the Norwegian Sea and adjacent waters

    DEFF Research Database (Denmark)

    Pampoulie, Christophe; Slotte, Aril; Oskarsson, Guomundur J.

    2015-01-01

    The genetic structure of Atlantic herring Clupea harengus L. was investigated in its north-easterly distribution in the Norwegian Sea and adjacent waters, using 23 neutral and one non-neutral (Cpa111) microsatellite loci. Fish from the suspected 2 main populations-the Norwegian spring......-spawning herring (NSSH) and the Icelandic summer-spawning herring (ISSH)-were collected at spawning locations in their respective spawning seasons from 2009 to 2012. Samples were also collected from Norwegian autumn spawning locations, from different local Norwegian fjords such as the inner part...... of Trondheimsfjorden, Lindas pollene, Landvikvannet and Lusterfjorden, as well as from suspected Faroese spawning components. The observed level of genetic differentiation was significant but low (F-ST = 0.007) and mostly attributable to the differentiation of the local Norwegian fjord populations. The locus Cpa111...

  7. Incidence of Ichthyophonus hoferi in Puget Sound fishes and its increase with age of Pacific herring

    Science.gov (United States)

    Hershberger, P.K.; Stick, K.; Bui, B.; Carroll, C.; Fall, B.; Mork, C.; Perry, J.A.; Sweeney, E.; Wittouck, J.; Winton, J.; Kocan, R.

    2002-01-01

    A recent decrease in the mean age of adult Pacific herring Clupea pallasi in Puget Sound was associated with a high prevalence of Ichthyophonus hoferi, a protistan parasite that can be highly pathogenic to Pacific herring. In Puget Sound, high intensities of I. hoferiinfection may be maintained in older cohorts of Pacific herring because the prevalence ofI. hoferi increased with age from 12% among juveniles to 58% among the oldest, age-6 and older cohorts. Low intensities of I. hoferi infection in the region may be maintained in alternative fish hosts, such as surf smelt Hypomesus pretiosus, Puget Sound rockfishSebastes emphaeus, Pacific tomcod Microgadus proximus, and speckled sanddabCithanichthys stigmaeus.

  8. Exxon Valdez oil spill restoration project final report: Prince William Sound Herring disease program (HDP), restoration project 070819

    Science.gov (United States)

    Hershberger, Paul; Elliott, Diane G.; Emmenegger, Eveline J.; Hansen, John D.; Kurath, Gael; Winton, James R.; Kocan, Richard; LaPatra, Scott

    2011-01-01

    Surveys of pathogens in Pacific herring from 2007 – 2010 indicated that Ichthyophonus, viral hemorrhagic septicemia virus, and erythrocytic necrosis virus are endemic in Prince William Sound and throughout the NE Pacific. Laboratory studies with VHSV indicated that multiple herring stocks are equally susceptible to the resulting disease, Pacific herring shed copious levels of VHSV (as high at 5x108 plaque-forming units/day) shortly after exposure, chronic and persistent infections can occur in Pacific herring, susceptibility of Pacific herring to VHS extends to the larval life stages but not the embryonic stages, and the prior exposure history of Pacific herring to VHSV can be determined post hoc. Laboratory studies involving Ichthyophonus indicated that schizonts can be inactivated with chlorine and iodine solutions, the parasite can survive for extended periods in saltwater but not freshwater, a low potential exists for cross contamination between in vitro explant cultures, infectious schizonts are released from the skin surface of infected herring, schizonts are not uniformly distributed throughout the skeletal muscle of infected Pacific herring, multiple types of Ichthyophonus exist with different genotypes and phenotypic traits, and temperature is an important factor influencing the infectivity of Ichthyophonus. Additional field and laboratory studies indicated that Ichthyophonus negatively influences the swimming performance of infected hosts and the negative impacts effects are exacerbated by increasing temperatures, American shad are an important reservoir of Ichthyophonus in the NE Pacific, Pacific herring are not susceptible to infectious hematopoietic necrosis (IHN), and Pacific herring will accept surgically implanted acoustic tags with negligible impacts on survival.

  9. Diets of nesting laughing gulls (Larus atricilla) at the Virginia Coast Reserve: observations from stable isotope analysis

    Science.gov (United States)

    Knoff, A.J.; Macko, S.A.; Erwin, R.M.

    2001-01-01

    Food web studies often ignore details of temporal, spatial, and intrapopulation dietary variation in top-level consumers. In this study, intrapopulation dietary variation of a dominant carnivore, the Laughing Gull (Larus atricilla), was examined using carbon, nitrogen, and sulfur isotope analysis of gull tissues as well as their prey (fish, invertebrates, and insects) from the Virginia Coast Reserve estuarine system. As earlier traditional diet studies found evidence of individual dietary specialization within gull populations, this study used stable isotope analysis to assess specialization in a coastal Laughing Gull population. Specifically, blood, muscle, and feather isotope values indicated significant intrapopulation dietary specialization. Some gulls relied more heavily on estuarine prey (mean blood δ13C = -17.5, δ15N = 12.6, and δ34S = 9.3), whereas others appeared to consume more foods of marine origin (mean blood δ13C = -19.4, δ15N = 14.8, and δ34S = 10.4). It is important to account for such dietary variability when assessing trophic linkages in dynamic estuarine systems.

  10. Viral tropism and pathology associated with viral hemorrhagic septicemia in larval and juvenile Pacific herring

    Science.gov (United States)

    Lovy, Jan; Lewis, N.L.; Hershberger, P.K.; Bennett, W.; Meyers, T.R.; Garver, K.A.

    2012-01-01

    Viral hemorrhagic septicemia virus (VHSV) genotype IVa causes mass mortality in wild Pacific herring, a species of economic value, in the Northeast Pacific Ocean. Young of the year herring are particularly susceptible and can be carriers of the virus. To understand its pathogenesis, tissue and cellular tropisms of VHSV in larval and juvenile Pacific herring were investigated with immunohistochemistry, transmission electron microscopy, and viral tissue titer. In larval herring, early viral tropism for epithelial tissues (6d post-exposure) was indicated by foci of epidermal thickening that contained heavy concentrations of virus. This was followed by a cellular tropism for fibroblasts within the fin bases and the dermis, but expanded to cells of the kidney, liver, pancreas, gastrointestinal tract and meninges in the brain. Among wild juvenile herring that underwent a VHS epizootic in the laboratory, the disease was characterized by acute and chronic phases of death. Fish that died during the acute phase had systemic infections in tissues including the submucosa of the gastrointestinal tract, spleen, kidney, liver, and meninges. The disease then transitioned into a chronic phase that was characterized by the appearance of neurological signs including erratic and corkscrew swimming and darkening of the dorsal skin. During the chronic phase viral persistence occurred in nervous tissues including meninges and brain parenchymal cells and in one case in peripheral nerves, while virus was mostly cleared from the other tissues. The results demonstrate the varying VHSV tropisms dependent on the timing of infection and the importance of neural tissues for the persistence and perpetuation of chronic infections in Pacific herring.

  11. Framing the problem with stakeholders: five views to herring fishery management

    DEFF Research Database (Denmark)

    Haapasaari, Päivi Elisabet; Mäntyniemi, Samu; Kuikka, Sakari

    Fisheries management is often subject to disputes due to high uncertainty and high values at stake. Such disputes call for improving the communication between parties, the understanding of policy processes, and transparency. We hypothesize that a transparent basis for a dialogue could be built...... should be taken into account in herring management, 2) Which variables are of primary interest, 3) What should be the objectives for herring management, and 4) What kind of management measures could or should be used to reach these objectives. The views of the stakeholders were built into causal maps...

  12. Chemical Characterization, Antioxidant and Enzymatic Activity of Brines from Scandinavian Marinated Herring Products

    DEFF Research Database (Denmark)

    Gringer, Nina; Osman, Ali; Nielsen, Henrik Hauch

    2014-01-01

    Brines generated during the last marination step in the production of marinated herring (Clupea harengus) were chemically characterized and analyzed for antioxidant and enzyme activities. The end-products were vinegar cured, spice cured and traditional barrel-salted herring with either salt...... or spices. The chemical characterization encompassed pH, dry matter, ash, salt, fatty acids, protein, polypeptide pattern, iron and nitrogen. The antioxidant activity was tested with three assays measuring: iron chelation, reducing power and radical scavenging activity. The enzymatic activity for peroxidase...

  13. Environmentally acquired lead, cadmium, and manganese in the cattle egret, Bubulcus ibis, and the laughing gull, Larus atricilla

    Energy Technology Data Exchange (ETDEWEB)

    Hulse, M; Mahoney, J S; Schroder, G D; Hacker, C S; Pier, S M

    1980-01-01

    Concentrations of lead, cadmium, and manganese in the tissues of cattle egrets and laughing gulls gathered from the Galveston Bay region of Texas were compared to determine if different patterns of accumulation exist. Lead, cadmium, and manganese levels in these species were within the range reported for other bird species. Lead levels in bones were comparable, but gulls had more lead in brain, liver, and kidney tissues than egrets had, which suggested a higher rate of accumulation or exposure. Because of their high abundance and comparable positions in the estuarine and terrestrial food webs, cattle egrets and laughing gulls may serve as convenient biological indicators to monitor potentially toxic substances in these ecosystems. (29 references, 7 tables)

  14. Hybridization among Arctic white-headed gulls (Larus spp.) obscures the genetic legacy of the Pleistocene

    Science.gov (United States)

    Sonsthagen, Sarah A.; Chesser, R. Terry; Bell, Douglas A.; Dove, Carla J.

    2012-01-01

    We studied the influence of glacial oscillations on the genetic structure of seven species of white-headed gull that breed at high latitudes (Larus argentatus, L. canus, L. glaucescens, L. glaucoides, L. hyperboreus, L. schistisagus, and L. thayeri). We evaluated localities hypothesized as ice-free areas or glacial refugia in other Arctic vertebrates using molecular data from 11 microsatellite loci, mitochondrial DNA (mtDNA) control region, and six nuclear introns for 32 populations across the Holarctic. Moderate levels of genetic structure were observed for microsatellites (FST= 0.129), introns (ΦST= 0.185), and mtDNA control region (ΦST= 0.461), with among-group variation maximized when populations were grouped based on subspecific classification. Two haplotype and at least two allele groups were observed across all loci. However, no haplotype/allele group was composed solely of individuals of a single species, a pattern consistent with recent divergence. Furthermore, northernmost populations were not well differentiated and among-group variation was maximized when L. argentatus and L. hyberboreus populations were grouped by locality rather than species, indicating recent hybridization. Four populations are located in putative Pleistocene glacial refugia and had larger t estimates than the other 28 populations. However, we were unable to substantiate these putative refugia using coalescent theory, as all populations had genetic signatures of stability based on mtDNA. The extent of haplotype and allele sharing among Arctic white-headed gull species is noteworthy. Studies of other Arctic taxa have generally revealed species-specific clusters as well as genetic structure within species, usually correlated with geography. Aspects of white-headed gull behavioral biology, such as colonization ability and propensity to hybridize, as well as their recent evolutionary history, have likely played a large role in the limited genetic structure observed.

  15. Effects of the Exxon Valdez oil spill on survival of Pacific herring eggs and viability of their larvae

    International Nuclear Information System (INIS)

    McGurk, M.D.; Warburton, H.D.; Parker, T.B.; Litke, M.; Marliave, J.B.

    1993-01-01

    The Exxon Valdez spill in March 1989 coincided with the spawning period of Pacific herring (Clupea pallasi) in the spill area. Adult herring were first observed near their spawning ground about a week after the spill. Spawners were concentrated in four major areas of Prince William Sound. The northeast and north areas were untouched by the spill, but the Naked Island archipelago and the northern tip of Montague Island were in the spill path. Previous research has shown that growth and mortality of free-swimming herring larvae were not significantly different between non-oiled and oiled areas of the Sound, suggesting that any effect of the oil spill on herring may have been restricted to the egg stage. This hypothesis was tested by measuring survival, hatching schedule, and viability of herring eggs collected from oiled and non-oiled areas of the Sound and incubated in laboratory aquaria. Variance analysis showed that egg survival and mean age of hatch varied with oil treatment, depth, and the interaction of treatment and depth. Six larval abnormalities were identified, all of which would render larvae effectively dead in a natural environment. Dry egg weight and yolk volume varied only with depth. Despite these findings, the population dynamics of both oiled and non-oiled herring eggs from the Sound in 1989 resembled the dynamics of natural, uncontaminated herring eggs. A possible reason for this similarity is that most eggs in the oil treatments may have been exposed to relatively low concentrations of hydrocarbons. 2 refs

  16. Teaching to the Test: A Very Large Red Herring

    Science.gov (United States)

    Phelps, Richard P.

    2016-01-01

    Elevating teaching-to-the-test to dogma, from the beginning with the distortion of J.J. Cannell's 1980s "Lake Wobegon" findings, has served to divert attention from scandals that should have threatened US educators' almost complete control of their own evaluation. Had the test cheating scandal Dr. Cannell uncovered been portrayed…

  17. Seasonal presence and potential influence of humpback whales on wintering Pacific herring populations in the Gulf of Alaska

    Science.gov (United States)

    Straley, Janice M.; Moran, John R.; Boswell, Kevin M.; Vollenweider, Johanna J.; Heintz, Ron A.; Quinn, Terrance J., II; Witteveen, Briana H.; Rice, Stanley D.

    2018-01-01

    This study addressed the lack of recovery of Pacific herring (Clupea pallasii) in Prince William Sound, Alaska, in relation to humpback whale (Megaptera novaeangliae) predation. As humpback whales rebound from commercial whaling, their ability to influence their prey through top-down forcing increases. We compared the potential influence of foraging humpback whales on three herring populations in the coastal Gulf of Alaska: Prince William Sound, Lynn Canal, and Sitka Sound (133-147°W; 57-61°N) from 2007 to 2009. Information on whale distribution, abundance, diet and the availability of herring as potential prey were used to correlate populations of overwintering herring and humpback whales. In Prince William Sound, the presence of whales coincided with the peak of herring abundance, allowing whales to maximize the consumption of overwintering herring prior to their southern migration. In Lynn Canal and Sitka Sound peak attendance of whales occurred earlier, in the fall, before the herring had completely moved into the areas, hence, there was less opportunity for predation to influence herring populations. North Pacific humpback whales in the Gulf of Alaska may be experiencing nutritional stress from reaching or exceeding carrying capacity, or oceanic conditions may have changed sufficiently to alter the prey base. Intraspecific competition for food may make it harder for humpback whales to meet their annual energetic needs. To meet their energetic demands whales may need to lengthen their time feeding in the northern latitudes or by skipping the annual migration altogether. If humpback whales extended their time feeding in Alaskan waters during the winter months, the result would likely be an increase in herring predation.

  18. 78 FR 33020 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Amendment 5

    Science.gov (United States)

    2013-06-03

    ...' consistency with the MSA and other applicable law. Following public comment, NMFS will determine if these... E permits, and vessels declaring herring carrier trips via VMS must notify NMFS Office of Law... accurately report the weight of fish, which is obtained by scale weights and/or volumetric estimates. Because...

  19. Spatial variation in growth, condition and maturation reaction norms of the Baltic herring Clupea harengus membras

    NARCIS (Netherlands)

    Vainikka, A.; Mollet, F.M.; Casini, M.; Gardmark, A.

    2009-01-01

    Understanding of spatial patterns in life-history traits can help fisheries management focus on biologically and functionally relevant stock units. In the present study, we examined life-history variation in growth, condition and maturation of the Baltic herring Clupea harengus membras among

  20. 75 FR 63791 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Amendment 4

    Science.gov (United States)

    2010-10-18

    ... submit Confidential Business Information or otherwise sensitive or protected information. NMFS will..., uncertainty related to expected catch of herring in the New Brunswick weir fishery and discard [[Page 63793... vessels issued Limited Access Incidental Catch Permits, and 2,272 vessels issued Open Access Permits...

  1. Use of herring bait to farm lobsters in the Gulf of Maine.

    Science.gov (United States)

    Grabowski, Jonathan H; Clesceri, Erika J; Baukus, Adam J; Gaudette, Julien; Weber, Matthew; Yund, Philip O

    2010-04-15

    Ecologists, fisheries scientists, and coastal managers have all called for an ecosystem approach to fisheries management, yet many species such as the American lobster (Homarus americanus) are still largely managed individually. One hypothesis that has yet to be tested suggests that human augmentation of lobster diets via the use of Atlantic herring (Clupea harengus) as bait may contribute to recent increases in lobster landings. Currently 70% of Atlantic herring landings in the Gulf of Maine are used as bait to catch lobsters in traps throughout coastal New England. We examined the effects of this herring bait on the diet composition and growth rate of lobsters at heavily baited vs. seasonally closed (i.e., bait free) sites in coastal Maine. Our results suggest that human use of herring bait may be subsidizing juvenile lobster diets, thereby enhancing lobster growth and the overall economic value and yield of one of the most valuable fisheries in the U.S. Our study illustrates that shifting to an ecosystem approach to fisheries management should require consideration of cross-fishery interactions.

  2. Bayesian stock assessment of Pacific herring in Prince William Sound, Alaska.

    Science.gov (United States)

    Muradian, Melissa L; Branch, Trevor A; Moffitt, Steven D; Hulson, Peter-John F

    2017-01-01

    The Pacific herring (Clupea pallasii) population in Prince William Sound, Alaska crashed in 1993 and has yet to recover, affecting food web dynamics in the Sound and impacting Alaskan communities. To help researchers design and implement the most effective monitoring, management, and recovery programs, a Bayesian assessment of Prince William Sound herring was developed by reformulating the current model used by the Alaska Department of Fish and Game. The Bayesian model estimated pre-fishery spawning biomass of herring age-3 and older in 2013 to be a median of 19,410 mt (95% credibility interval 12,150-31,740 mt), with a 54% probability that biomass in 2013 was below the management limit used to regulate fisheries in Prince William Sound. The main advantages of the Bayesian model are that it can more objectively weight different datasets and provide estimates of uncertainty for model parameters and outputs, unlike the weighted sum-of-squares used in the original model. In addition, the revised model could be used to manage herring stocks with a decision rule that considers both stock status and the uncertainty in stock status.

  3. Climate influence on Baltic cod, sprat, and herring stock–recruitment relationships

    DEFF Research Database (Denmark)

    Margonski, Piotr; Hansson, Sture; Tomczak, Maciej

    2010-01-01

    is significantly related to spawning stock biomass, climatic forcing, and feeding conditions and (ii) by acknowledging these drivers, management decisions can be improved. Climate impact expressed by climatic indices or changes in water temperature was included in all the final models. Recruitment of the herring...

  4. The parasite Ichthyophonus sp. in Pacific herring from the coastal NE Pacific

    Science.gov (United States)

    Hershberger, Paul K.; Gregg, Jacob L.; Hart, Lucas M.; Moffitt, Steve; Brenner, Richard L.; Stick, K.; Coonradt, Eric; Otis, E. O.; Vollenweider, Johanna J.; Garver, Kyle A.; Lovy, Jan; Meyers, T.R.

    2016-01-01

    The protistan parasite Ichthyophonus occurred in populations of Pacific herring Clupea pallasii Valenciennes throughout coastal areas of the NE Pacific, ranging from Puget Sound, WA north to the Gulf of Alaska, AK. Infection prevalence in local Pacific herring stocks varied seasonally and annually, and a general pattern of increasing prevalence with host size and/or age persisted throughout the NE Pacific. An exception to this zoographic pattern occurred among a group of juvenile, age 1+ year Pacific herring from Cordova Harbor, AK in June 2010, which demonstrated an unusually high infection prevalence of 35%. Reasons for this anomaly were hypothesized to involve anthropogenic influences that resulted in locally elevated infection pressures. Interannual declines in infection prevalence from some populations (e.g. Lower Cook Inlet, AK; from 20–32% in 2007 to 0–3% during 2009–13) or from the largest size cohorts of other populations (e.g. Sitka Sound, AK; from 62.5% in 2007 to 19.6% in 2013) were likely a reflection of selective mortality among the infected cohorts. All available information for Ichthyophonus in the NE Pacific, including broad geographic range, low host specificity and presence in archived Pacific herring tissue samples dating to the 1980s, indicate a long-standing host–pathogen relationship.

  5. Feeding and growth of larval herring,Clupea harengus, in relation to density of copepod nauplii

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Munk, Peter

    1986-01-01

    Feeding and growth rates of 1–3 wk old herring larvae from four different stocks were compared in laboratory experiments (8°C). For most of the larval groups, feeding rate was saturated at nauplii (Acartia tonsa, nauplii stages 3–5) densities over 301−1 (5 μg d.w. 1−1). Specific growth rate incre...

  6. Organochlorine pesticides and polychlorinated biphenyls in herring from the southern Baltic, 1983

    Energy Technology Data Exchange (ETDEWEB)

    Falandysz, J

    1986-02-01

    Hexachlorobenzene (HCB), alpha-, beta-, gamma- and delta-benzenehexachloride (BHC, HCH), p,p'-DDE, o,p'-DDD, o,p'-DDT, p,p'-DDD and p,p'-DDT (sigma DDT) and polychlorinated biphenyls (PCB) levels have been determined in muscle tissue of 187 herring (Clupea harengus) netted during 1983 in a different regions in the southern part of the Baltic Sea. The mean levels found for herring muscle tissue related to wet weight (microgram/kg) were: 14 HCB, 18 alpha-BHC, 23 beta-BHC, 14 gamma-BHC, delta-BHC remained undetected, 56 sigma BHC, 115 p,p'-DDE, o,p'-DDD and o,p'-DDT remained undetected, 84 p,p'-DDD, 51 p,p'-DDT, 250 sigma DDT and 530 PCB. The levels of organochlorine pesticides determined in wet muscles or extractable lipids of herring are nearly 2-3 times as high as those noted in fish sampled in the same area in two years before, while for PCBs the wet weight levels were comparable, and when based on a lipid weight are somewhat higher. The results are compared with levels found in herring collected in different regions of the Baltic Sea during 1965-1983, and reported previously by other authors.

  7. Bayesian stock assessment of Pacific herring in Prince William Sound, Alaska.

    Directory of Open Access Journals (Sweden)

    Melissa L Muradian

    Full Text Available The Pacific herring (Clupea pallasii population in Prince William Sound, Alaska crashed in 1993 and has yet to recover, affecting food web dynamics in the Sound and impacting Alaskan communities. To help researchers design and implement the most effective monitoring, management, and recovery programs, a Bayesian assessment of Prince William Sound herring was developed by reformulating the current model used by the Alaska Department of Fish and Game. The Bayesian model estimated pre-fishery spawning biomass of herring age-3 and older in 2013 to be a median of 19,410 mt (95% credibility interval 12,150-31,740 mt, with a 54% probability that biomass in 2013 was below the management limit used to regulate fisheries in Prince William Sound. The main advantages of the Bayesian model are that it can more objectively weight different datasets and provide estimates of uncertainty for model parameters and outputs, unlike the weighted sum-of-squares used in the original model. In addition, the revised model could be used to manage herring stocks with a decision rule that considers both stock status and the uncertainty in stock status.

  8. Lumpers or splitters? Evaluating recovering and management plans for metapopulations of herring

    NARCIS (Netherlands)

    Kell, L.T.; Dickey-Collas, M.; Hintzen, N.T.; Nash, R.D.M.; Pilling, G.M.

    2009-01-01

    The long-term management of a stock representing a metapopulation has been simulated in a case study loosely based upon herring to the west of the British isles, where stocks are currently assessed and managed by management area, although there is evidence of mixing between stocks (in terms of

  9. Influence of ionizing radiation on the fatty acid composition of herring fillets

    International Nuclear Information System (INIS)

    Adam, S.; Paul, G.; Ehlermann, D.

    1982-01-01

    The effect of γ-irradiation (absorbed dose: 50 kGy, dose-rate: 2.9 kGy/h) on the distribution of fatty acid components in herring fillets has been examined using high-resolution gas chromatographic methods. Radiolytic treatment at 0 0 C and exclusion of atmospheric oxygen caused no significant decrease in the relative amounts of the constituent saturated, monounsaturated and polyunsaturated fatty acid components. Specifically, eicosapentaenoic acid (20:5) and docosahexaenoic acid (22:6), which are of particular physiological interest were not affected by γ-rays, even after additional storage of the irradiated material at 0 0 C for 4 weeks. Irradiation of oil extracted from herring fillets or of herring oil/water emulsions under aerobic conditions, however, destroyed eicosapentaenoic acid and docosahexaenoic acid significantly. The loss of radio-resistance - as compared to the radiation-induced processes in the fillets - is explained by the absence of proteins, which effectively protect the lipid components from radiolytic decomposition. It is concluded that the commercial radiation processing of herring at the recommended dose levels (1 to 2 kGy) should not reduce the content of unsaturated fatty acid components. (author)

  10. Histopathology of adult Pacific herring in Prince William Sound, Alaska, after the Exxon Valdez oil spill

    International Nuclear Information System (INIS)

    Marty, G. S.; Okihiro, M. S.; Hinton, D. E.; Brown, E. D.; Hanes, D.

    1999-01-01

    The histopathology of Pacific herring sampled from oiled sites in Prince William Sound, Alaska, three weeks after the 1989 Exxon Valdez oil spill, is discussed. All samples showed multifocal hepatic necrosis and significantly increased tissue concentrations of polynuclear aromatic hydrocarbons (PAH). In contrast, Pacific herring from reference sites in 1989 and from all sites in 1990 and 1991 did not have hepatic necrosis or increase PAH concentrations. Naphthalenes were the predominant PAH in all tissue samples. The development of hepatic necrosis and the predominance of naphthalenes in samples from 1989 is considered consistent with results obtained from recent laboratory studies indicating that crude oil exposure resulted in dose-dependent expression of viral hemorrhagic septicemia virus (VHSV). It was concluded that adult Pacific herring in Prince William Sound were likely exposed to Exxon Valdez oil in April 1989. Because Pacific herring near spawning condition in early spring are in a state of physiological stress, the added stress of oil exposure in 1989 could reasonably have led to expression of VHSV in these fish. The findings suggest that the immediate response to future large toxic spills should include consideration of the potential interaction of multiple stressors in exposed individuals. 29 refs., 7 tabs., 1 fig

  11. Use of herring bait to farm lobsters in the Gulf of Maine.

    Directory of Open Access Journals (Sweden)

    Jonathan H Grabowski

    2010-04-01

    Full Text Available Ecologists, fisheries scientists, and coastal managers have all called for an ecosystem approach to fisheries management, yet many species such as the American lobster (Homarus americanus are still largely managed individually. One hypothesis that has yet to be tested suggests that human augmentation of lobster diets via the use of Atlantic herring (Clupea harengus as bait may contribute to recent increases in lobster landings. Currently 70% of Atlantic herring landings in the Gulf of Maine are used as bait to catch lobsters in traps throughout coastal New England.We examined the effects of this herring bait on the diet composition and growth rate of lobsters at heavily baited vs. seasonally closed (i.e., bait free sites in coastal Maine. Our results suggest that human use of herring bait may be subsidizing juvenile lobster diets, thereby enhancing lobster growth and the overall economic value and yield of one of the most valuable fisheries in the U.S.Our study illustrates that shifting to an ecosystem approach to fisheries management should require consideration of cross-fishery interactions.

  12. The parasite Ichthyophonus sp. in Pacific herring from the coastal NE Pacific.

    Science.gov (United States)

    Hershberger, P K; Gregg, J L; Hart, L M; Moffitt, S; Brenner, R; Stick, K; Coonradt, E; Otis, E O; Vollenweider, J J; Garver, K A; Lovy, J; Meyers, T R

    2016-04-01

    The protistan parasite Ichthyophonus occurred in populations of Pacific herring Clupea pallasii Valenciennes throughout coastal areas of the NE Pacific, ranging from Puget Sound, WA north to the Gulf of Alaska, AK. Infection prevalence in local Pacific herring stocks varied seasonally and annually, and a general pattern of increasing prevalence with host size and/or age persisted throughout the NE Pacific. An exception to this zoographic pattern occurred among a group of juvenile, age 1+ year Pacific herring from Cordova Harbor, AK in June 2010, which demonstrated an unusually high infection prevalence of 35%. Reasons for this anomaly were hypothesized to involve anthropogenic influences that resulted in locally elevated infection pressures. Interannual declines in infection prevalence from some populations (e.g. Lower Cook Inlet, AK; from 20-32% in 2007 to 0-3% during 2009-13) or from the largest size cohorts of other populations (e.g. Sitka Sound, AK; from 62.5% in 2007 to 19.6% in 2013) were likely a reflection of selective mortality among the infected cohorts. All available information for Ichthyophonus in the NE Pacific, including broad geographic range, low host specificity and presence in archived Pacific herring tissue samples dating to the 1980s, indicate a long-standing host-pathogen relationship. © 2015 John Wiley & Sons Ltd.

  13. Quality of crude fish oil extracted from herring byproducts of varying states of freshness

    NARCIS (Netherlands)

    Aidos, I.M.; Padt, van der A.; Boom, R.M.; Luten, J.B.

    2003-01-01

    Herring byproducts were stored at 2 and 15degreesC for up to 72 h. Over time, significant increases of total volatile bases (TVB), histamine, putrescine, cadaverine, and tyramine were detected. However, only tyramine and TVB levels were temperature-dependent. The level of total polyunsaturated

  14. Realized habitats of early-stage North Sea herring: looking for signals of environmental change

    DEFF Research Database (Denmark)

    Röckmann, C.; Dickey-Collas, M.; Payne, Mark

    2011-01-01

    Realized habitats of North Sea herring for two larval and two juvenile stages were estimated over the past 30 years, using abundances from surveys tied to modelled estimates of temperature and salinity. Newly hatched larvae (NHL) were found mainly in water masses of 9–11°C, pre-metamorphosis larvae...

  15. Feathered Detectives: Real-Time GPS Tracking of Scavenging Gulls Pinpoints Illegal Waste Dumping.

    Directory of Open Access Journals (Sweden)

    Joan Navarro

    Full Text Available Urban waste impacts human and environmental health, and waste management has become one of the major challenges of humanity. Concurrently with new directives due to manage this human by-product, illegal dumping has become one of the most lucrative activities of organized crime. Beyond economic fraud, illegal waste disposal strongly enhances uncontrolled dissemination of human pathogens, pollutants and invasive species. Here, we demonstrate the potential of novel real-time GPS tracking of scavenging species to detect environmental crime. Specifically, we were able to detect illegal activities at an officially closed dump, which was visited recurrently by 5 of 19 GPS-tracked yellow-legged gulls (Larus michahellis. In comparison with conventional land-based surveys, GPS tracking allows a much wider and cost-efficient spatiotemporal coverage, even of the most hazardous sites, while GPS data accessibility through the internet enables rapid intervention. Our results suggest that multi-species guilds of feathered detectives equipped with GPS and cameras could help fight illegal dumping at continental scales. We encourage further experimental studies, to infer waste detection thresholds in gulls and other scavenging species exploiting human waste dumps.

  16. Maternal transfer of organohalogen contaminants and metabolites to eggs of Arctic-breeding glaucous gulls

    International Nuclear Information System (INIS)

    Verreault, Jonathan; Villa, Rosa A.; Gabrielsen, Geir W.; Skaare, Janneche U.; Letcher, Robert J.

    2006-01-01

    Eggs of seabirds have routinely been used as indicators of environmental pollution in the Arctic. However, the variability in organohalogen concentration and composition associated with the laying sequence, have not been defined. We examined a suite of PCBs, organochlorine (OC) pesticides and by-products, polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs) and methylsulfonyl- (MeSO 2 ) PCBs in complete 3-egg clutches of glaucous gulls (Larus hyperboreus), and plasma samples of the laying females collected from the Norwegian Arctic. ΣPCB, ΣOC and ΣPBDE, but not ΣMeSO 2 -PCB, concentrations in eggs were positively associated, with increasing magnitude and significance from the first through the last-laid egg, with concentrations in female plasma. However, the concentrations of these organohalogen classes fluctuated irrespective of the laying order in the clutch. In general, maternal transfer favored low K ow and/or less persistent compounds, whereas the recalcitrant and/or higher-halogenated compounds were less readily transferred, and consequently more selectively retained in the mother. - Concentrations of organohalogen contaminants and metabolites in eggs of glaucous gulls do not fluctuate with the laying order in a three-egg clutch

  17. Relationships between reproductive performance and organochlorine contaminants in great black-backed gulls (Larus marinus)

    International Nuclear Information System (INIS)

    Helberg, Morten; Bustnes, Jan Ove; Erikstad, Kjell Einar; Kristiansen, Kai Ove; Skaare, Janneche Utne

    2005-01-01

    The great black-backed gull Larus marinus is a top predator in subarctic and temperate marine ecosystems, and the aim of this study was to investigate if organochlorines (OCs) were related to reproductive performance in this species at the subarctic parts of the Norwegian Coast. We measured blood levels of various OCs in 53 breeding birds. The OC levels were relatively low compared to levels found in nearby arctic areas. In females, however, there was a significant positive relationship between blood concentrations of OCs, especially hexachlorobenzene (HCB) and, p,p'-dichlorodiphenyldichloroethylene (DDE), and egg laying date, and a positive relationship between the probability of nest predation and blood concentration of β-hexachlorocyclohexane (β-HCH), oxychlordane, and DDE. In females with high levels of OCs, especially persistent polychlorinated biphenyls (PCBs), there was also a decline in egg volume as egg laying progressed; i.e. the second and third laid egg were relatively smaller, compared to females with low OC levels. No relationships between reproductive parameters and OC levels were found in males. - Elevated blood concentrations of organochlorine contaminants correlate with poor reproductive performance in female great black-backed gulls

  18. Molecular evidence for extra-pair paternity and intraspecific brood parasitism in the Black-headed Gull

    Czech Academy of Sciences Publication Activity Database

    Ležalová-Piálková, Radka

    2011-01-01

    Roč. 152, č. 2 (2011), s. 291-295 ISSN 0021-8375 Institutional research plan: CEZ:AV0Z60930519 Keywords : Black-headed Gull * genetic mating system * extra-pair paternity * intraspecific brood parasitism Subject RIV: EG - Zoology Impact factor: 1.636, year: 2011

  19. Kelp and dolphin gulls cause perineal wounds in South American fur seal pups (Arctocephalus australis) at Guafo Island, Chilean Patagonia.

    Science.gov (United States)

    Seguel, Mauricio; Muñoz, Francisco; Montalva, Felipe; Perez-Venegas, Diego; Pavés, Héctor; Gottdenker, Nicole

    2017-07-01

    During five reproductive seasons, we documented the presence, extent and origin of perineal wounds in South American fur seal pups ( Arctocephalus australis ) on Guafo Island, Northern Chilean Patagonia. The seasonal prevalence of perineal wounds ranged from 5 to 9%, and new cases were more common at the end of the breeding season (February), when pups were on average two months old and were actively expelling hookworms ( Uncinaria sp). Histologically, wounds corresponded to marked ulcerative lymphoplasmacytic and histiocytic dermatitis with granulation tissue and mixed bacterial colonies. In 2015 and 2017, kelp gulls ( Larus dominicanus ) and dolphin gulls ( Leucophaeus scoresbii ) were observed picking and wounding the perineal area of marked pups. This behaviour occurred more frequently after the pups' defecation, when sea gulls engaged in consumption of pups' faeces. The affected pups usually had moderate to marked hookworm infections along with bloody diarrhoea and anaemia. Pups with severe wounds (23% of affected animals) had swollen perineal areas and signs of secondary systemic bacterial infection. We propose that seagulls on Guafo Island have learned to consume remains of blood and parasites in the faeces of pups affected by hookworm infection, causing perineal wounds during this process. We conclude that this perineal wounding is an unintentional, occasional negative effect of an otherwise commensal gull-fur seal relationship.

  20. Experimental infection of highly pathogenic avian influenza virus H5N1 in black-headed gulls (Chroicocephalus ridibundus)

    NARCIS (Netherlands)

    A. Ramis (Antonio); G. van Amerongen (Geert); M.W.G. van de Bildt (Marco); L.M.E. Leijten (Lonneke); R. Vanderstichel (R.); A.D.M.E. Osterhaus (Albert); T. Kuiken (Thijs)

    2014-01-01

    textabstractHistorically, highly pathogenic avian influenza viruses (HPAIV) rarely resulted in infection or clinical disease in wild birds. However, since 2002, disease and mortality from natural HPAIV H5N1 infection have been observed in wild birds including gulls. We performed an experimental

  1. Monitoring organic contaminants in eggs of glaucous and glaucous-winged gulls (Larus hyperboreus and Larus glaucescens) from Alaska

    International Nuclear Information System (INIS)

    Vander Pol, Stacy S.; Becker, Paul R.; Ellisor, Michael B.; Moors, Amanda J.; Pugh, Rebecca S.; Roseneau, David G.

    2009-01-01

    Gull eggs have been used to monitor contaminants in many parts of the world. The Seabird Tissue Archival and Monitoring Project (STAMP) is a long-term program designed to track trends in pollutants in northern marine environments using seabird eggs. Glaucous and glaucous-winged gull (Larus hyperboreus and Larus glaucescens) eggs collected in 2005 from seven Alaskan colonies were analyzed for organic contaminants. Concentrations ranged from below detection limits to 322 ng g -1 wet mass in one egg for 4,4'-DDE and differed among the samples collected in the Gulf of Alaska and Bering and Chukchi Seas. Chick growth and survival rates may be affected by the contaminant levels found in the eggs, but the eggs should be safe for human consumption if they are eaten in small quantities. STAMP plans to continue collecting and banking gull eggs for future real-time and retrospective analyses. - Organic contaminant concentrations in Alaskan gull eggs could possibly be affecting chick growth and survival rates, but the eggs should be safe for humans to eat in small quantities

  2. On the Ontogeny of Display Behaviour in the Black-Headed Gull : I. The Gradual Emergence of the Adult Forms

    NARCIS (Netherlands)

    Groothuis, Ton

    1989-01-01

    The central question in this paper concerns the mechanism by which displays develop their species-specific sterotyped form. To this end the ontogeny of display behaviour in the black-headed gull was studied in birds kept and raised in aviaries. First it was analyzed whether the complete adult form

  3. Experience modulates both aromatase activity and the sensitivity of agonistic behaviour to testosterone in black-headed gulls

    NARCIS (Netherlands)

    Ros, Albert F. H.; Franco, Aldina M. A.; Groothuis, Ton G. G.

    2009-01-01

    In young black-headed gulls (Larus ridibundus), exposure to testosterone increases the sensitivity of agonistic behaviour to a subsequent exposure to this hormone. The aim of this paper is twofold: to analyze whether social experience, gained during testosterone exposure, mediates this increase in

  4. The relationship between carbon stable isotope ratios of hatchling down and egg yolk in Black-headed Gulls

    NARCIS (Netherlands)

    Klaassen, M.R.J.; Baarspul, T.; Dekkers, T.; Van Tienen, P.

    2004-01-01

    We reconstructed the nutrient source for egg synthesis by sampling Black-headed Gull (Larus ridibundus) eggs for yolk, analyzing their carbon stable isotope ratio, and comparing that to hatchling down. Most of the variation in carbon stable isotope ratio was explained by differences between nests,

  5. An analysis of the potential for oil spill effects on the herring population of Prince William Sound, Alaska

    International Nuclear Information System (INIS)

    Pearson, W.H.; Elston, R.A.; Bienert, R.W.; Drum, A.S.; Antrim, L.D.

    1996-01-01

    The impact of the Exxon Valdez oil spill on the herring population in Prince William Sound, was studied. Following the incident in 1989, there was no commercial harvest of herring. However, 1990 through 1992 proved to have above average, record harvests. This was followed by a dramatic decline in 1993 which was generally attributed to the oil spill. An examination of the scientific data was conducted. The main hypotheses for the decline were tested. These hypotheses attributed the decline to: (1) the oil spill itself, (2) a combination of increasing herring biomass and decreasing food supply, (3) disease, and (4) other natural stochastic processes. Based on the review of the data and the analysis of the four alternative hypotheses, it was concluded that the population decline of 1993 was the result of a combination of increasing herring biomass and decreasing food supply. No connection to the Exxon Valdez incident was evident. 22 refs., 6 figs

  6. Economic gains from introducing international ITQs - the case of the mackerel and herring fisheries in the Northeast Atlantic

    DEFF Research Database (Denmark)

    Thøgersen, Thomas Talund; Eigaard, Ole Ritzau; Fitzpatrick, M.

    2015-01-01

    Achieving a balance between fishing capacity and fishing opportunities is one of the major challenges in European fisheries. One way to achieve this is to introduce individual tradable quotas or similar management measures. In several mackerel and herring fisheries in the Northeast Atlantic...... that the gross cash flow can be improved by 21% by allowing the mackerel and herring quotas to be traded internationally in the Northeast Atlantic. This rent gain arises mainly from increased productivity by allowing tradability between areas and fleets. The analysis also shows that the Danish pelagic fleet...... will gain from increasing its share of mackerel and herring quotas, whereas the Irish fleets are incentivised to sell quota, if individual quotas are allowed to be traded among countries. This result is in line with the qualitative analyses that show that Irish fishermen targeting herring in the Celtic Sea...

  7. Forage fish quality: seasonal lipid dynamics of herring (Clupea harengus L.) and sprat (Sprattus sprattus L.) in the Baltic Sea

    DEFF Research Database (Denmark)

    Røjbek, Maria; Tomkiewicz, Jonna; Jacobsen, Charlotte

    2013-01-01

    seasonally with high levelstowards the end of the annual zooplankton production cycle, succeeded by a decline. Lipid content and fatty acid composition differed significantly between sprat and herring. Sprat lipid content was higher than herring, increasing with fish size and characterized by large......This study investigates lipid content and fatty acid composition of two important forage fish, sprat (Sprattus sprattus) and herring (Clupea harengus) in the Baltic Sea ecosystem. Seasonal variation in lipids was studied during three periods following the annual reproductive cycle considering...... potential differences relating to fish size, sex, and reproductive status. The isopod Saduria entomon, being at times an important prey for predatory fish, was included for comparison. In both sprat and herring, lipid content and absolute contents of essential polyunsaturated fatty acids (PUFAs) varied...

  8. Mercury and other metals in eggs and feathers of glaucous-winged gulls (Larus glaucescens) in the Aleutians

    Science.gov (United States)

    Gochfeld, Michael; Jeitner, Christian; Burke, Sean; Volz, Conrad D.; Snigaroff, Ronald; Snigaroff, Daniel; Shukla, Tara; Shukla, Sheila

    2014-01-01

    Levels of mercury and other contaminants should be lower in birds nesting on isolated oceanic islands and at high latitudes without any local or regional sources of contamination, compared to more urban and industrialized temperate regions. We examined concentrations of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in the eggs, and the feathers of fledgling and adult glaucous-winged gulls (Larus glaucescens) nesting in breeding colonies on Adak, Amchitka, and Kiska Islands in the Aleutian Chain of Alaska in the Bering Sea/North Pacific. We tested the following null hypotheses: 1) There were no differences in metal levels among eggs and feathers of adult and fledgling glaucous-winged gulls, 2) There were no differences in metal levels among gulls nesting near the three underground nuclear test sites (Long Shot 1965, Milrow 1969, Cannikin 1971) on Amchitka, 3) There were no differences in metal levels among the three islands, and 4) There were no gender-related differences in metal levels. All four null hypotheses were rejected at the 0.05 level, although there were few differences among the three test sites on Amchitka. Eggs had the lowest levels of cadmium, lead, and mercury, and the feathers of adults had the lowest levels of selenium. Comparing only adults and fledglings, adults had higher levels of cadmium, chromium, lead and mercury, and fledglings had higher levels of arsenic, manganese and selenium. There were few consistent interisland differences, although levels were generally lower for eggs and feathers from gulls on Amchitka compared to the other islands. Arsenic was higher in both adult feathers and eggs from Amchitka compared to Adak, and chromium and lead were higher in adult feathers and eggs from Adak compared to Amchitka. Mercury and arsenic, and chromium and manganese levels were significantly correlated in the feathers of both adult and fledgling gulls. The feathers of males had significantly higher levels of chromium and

  9. Quantification of biomolecules in herring (Clupea harengus) industry processing waters and their recovery using electroflocculation and ultrafiltration

    DEFF Research Database (Denmark)

    Osman, Ali; Gringer, Nina; Svendsen, Tore

    2015-01-01

    Four types of herring industry processing waters; refrigerated sea water (RSW), storage water (SW), processing water from cutting (PW) and pre-salting brines (SB) were subjected to chemical characterization and biomolecule recovery using electroflocculation (EF) and ultrafiltration (UF). The high......Four types of herring industry processing waters; refrigerated sea water (RSW), storage water (SW), processing water from cutting (PW) and pre-salting brines (SB) were subjected to chemical characterization and biomolecule recovery using electroflocculation (EF) and ultrafiltration (UF...

  10. Gene-associated markers can assign origin in a weakly structured fish, Atlantic herring

    DEFF Research Database (Denmark)

    Bekkevold, Dorte; Helyar, Sarah J.; Limborg, Morten T.

    2015-01-01

    , there are relatively few examples in marine fish displaying accurate origin assignment. We synthesize data for 156 single-nucleotide polymorphisms typed in 1039 herring, Clupea harengus L., spanning the Northeast Atlantic to develop a tool that allows assignment of individual herring to their regional origin. We show......Regulations on the exploitation of populations of commercially important fish species and the ensuing consumer interest in sustainable products have increased the need to accurately identify the population of origin of fish and fish products. Although genomics-based tools have proven highly useful...... the method's suitability to address specific biological questions, as well as management applications. We analyse temporally replicated collections from two areas, the Skagerrak (n = 81, 84, 66) and the western Baltic (n = 52, 52). Both areas harbour heavily fished mixed-origin stocks, complicating...

  11. Recruitment in a changing environment: the 2000s North Sea herring recruitment failure

    DEFF Research Database (Denmark)

    Payne, Mark; Hatfield, E.M.C.; Dickey-Collas, M.

    2009-01-01

    Environmentally induced change appears to be impacting the recruitment of North Sea herring (Clupea harengus). Despite simultaneously having a large adult population, historically low exploitation, and Marine Stewardship Council accreditation (implying sustainability), there have been an unpreced......Environmentally induced change appears to be impacting the recruitment of North Sea herring (Clupea harengus). Despite simultaneously having a large adult population, historically low exploitation, and Marine Stewardship Council accreditation (implying sustainability), there have been...... an unprecedented 6 sequential years of poor juvenile production (recruitment). Analysis suggests that the poor recruitment arises during the larval overwintering phase, with recent survival rates greatly reduced. Contemporary warming of the North Sea has caused significant changes in the plankton community...

  12. Foraging behaviour and prey size spectra of larval herring Clupea harengus

    DEFF Research Database (Denmark)

    Munk, Peter

    1992-01-01

    size groups of larval herring Clupea harengus L. were studied when preying on 6 size groups of copepods. Larval swimming and attack behaviour changed with prey size and were related to the ratio between prey length and larval length. The effective search rate showed a maximum when prey length was about......, that the available biomass of food as a proportion of the predator biomass will not increase. In order to assess the uniformity of relative prey size spectra of herring larvae and their background in larval foraging behaviour, a set of experimental and field investigations has been carried out. In the experiments, 4...... in the biomass spectra of the environment is important to larval growth and survival....

  13. Methods for conducting bioassays using embryos and larvae of Pacific herring, Clupea pallasi.

    Science.gov (United States)

    Dinnel, Paul A; Middaugh, Douglas P; Schwarck, Nathan T; Farren, Heather M; Haley, Richard K; Hoover, Richard A; Elphick, James; Tobiason, Karen; Marshall, Randall R

    2011-02-01

    The rapid decrease of several stocks of Pacific herring, Clupea pallasi, in Puget Sound, Washington, has led to concerns about the effects of industrial and nonpoint source contamination on the embryo and larval stages of this and related forage fish species. To address these concerns, the state of Washington and several industries have funded efforts to develop embryo and larval bioassay protocols that can be used by commercial laboratories for routine effluent testing. This article presents the results of research to develop herring embryo and larval bioassay protocols. Factors evaluated during protocol development included temperature, salinity, dissolved oxygen (DO), light intensity, photoperiod, larval feeding regimes, use of brine and artificial sea salts, gonad sources, collection methods, and egg quality.

  14. Recruitment decline in North Sea herring is accompanied by reduced larval growth rates

    DEFF Research Database (Denmark)

    Payne, Mark; Ross, Stine Dalmann; Worsøe Clausen, Lotte

    2013-01-01

    The stock of North Sea autumn spawning herring (Clupea harengus L.) has shown an unprecedented sequence of ten years of sharply reduced recruitment, in spite of a high spawning biomass. Recent work has identified this below-expected recruitment as being determined during the larval phase: however...... rate of 8%, concurrent with the reduced larval survival and recruitment, was identified: after correcting for the effect of other explanatory variables (e.g. temperature changes), the gross reduction was found to be 12%. This reduction is most probably due to changes in either the amount or quality...... and larvae survival, thereby narrowing the range of potential mechanisms underlying the observed reduction in the recruitment of North Sea autumn spawning herring...

  15. Viability and infectivity of Ichthyophonus sp. in post-mortem Pacific herring, Clupea pallasii.

    Science.gov (United States)

    Kocan, Richard; Hart, Lucas; Lewandowski, Naomi; Hershberger, Paul

    2014-12-01

    Ichthyophonus-infected Pacific herring, Clupea pallasii , were allowed to decompose in ambient seawater then serially sampled for 29 days to evaluate parasite viability and infectivity for Pacific staghorn sculpin, Leptocottus armatus . Ichthyophonus sp. was viable in decomposing herring tissues for at least 29 days post-mortem and could be transmitted via ingestion to sculpin for up to 5 days. The parasite underwent morphologic changes during the first 48 hr following death of the host that were similar to those previously reported, but as host tissue decomposition progressed, several previously un-described forms of the parasite were observed. The significance of long-term survival and continued morphologic transformation in the post-mortem host is unknown, but it could represent a saprozoic phase of the parasite life cycle that has survival value for Ichthyophonus sp.

  16. Protein synthesis, growth and energetics in larval herring (Clupea harengus) at different feeding regimes

    DEFF Research Database (Denmark)

    Houlihan, D F; Pedersen, B H; Steffensen, J F

    1995-01-01

    Rates of growth, protein synthesis and oxygen consumption were measured in herring larvae, Clupea harengus, in order to estimate the contribution that protein synthesis makes to oxygen consumption during rapid growth at 8°C. Protein synthesis rates were determined in larvae 9 to 17 d after hatching....... Larvae were bathed in (3)H phenylalanine for several hours and the free pool and protein-bound phenylalanine specific radioactivities were determined.Fractional rates of protein synthesis increased 5 to 11 fold with feeding after a period of fasting. Efficiencies of retention of synthesized protein were...... approximately 50% during rapid growth. Rapid growth in herring larvae thus appears to be characterized by moderate levels of protein turnover similar to those obtained for larger fish. Increases in growth rate occurred without changes in RNA concentration, i.e., the larvae increased the efficiency of RNA...

  17. Audouin's gull chicks as bioindicators of mercury pollution at different breeding locations in the western Mediterranean

    International Nuclear Information System (INIS)

    Sanpera, Carolina; Moreno, Roci'o; Ruiz, Xavier; Jover, Lluis

    2007-01-01

    Mercury levels of Audouin's gull are amongst the highest for Mediterranean seabirds, and have been mainly attributed to its piscivorous habits in these naturally Hg rich waters. Moreover, two additional factors could enhance its mercury intake: the consumption of discarded fish (which attain higher concentrations) and/or feeding in areas receiving Hg anthropogenic inputs. In order to differentiate the relevance of both sources we analysed Hg and stable isotopes of chick feathers from different breeding locations in western Mediterranean: one in its northern part (Ebro Delta) and two southern (Chafarinas Isl. and Alboran Isl.). The results from stable isotopes indicate that consumption of discards is higher at Alboran Isl., followed by the Ebro Delta and Chafarinas Isl. Thus, the higher mercury levels found in the Ebro Delta cannot be explained uniquely by the contribution of discarded fish to diet, but local pollution caused by the river Ebro waters accounts for Hg differences observed

  18. Plastic consumption and diet of Glaucous-winged Gulls (Larus glaucescens).

    Science.gov (United States)

    Lindborg, Valerie A; Ledbetter, Julia F; Walat, Jean M; Moffett, Cinamon

    2012-11-01

    We analyzed dietary habits and presence of plastic in 589 boluses of Glaucous-winged Gulls (Larus glaucescens) as one of two studies on the impact of plastics on marine life in the US Salish Sea. Volunteers dissected boluses collected (2007-2010) from Protection Island, Washington. Components were separated into 23 food and non-food categories. Plastic was found in 12.2% of boluses, with plastic film being the most common plastic form. No diet specialization was observed. Vegetation was the most abundant component, found in 91.3% of boluses. No relationship was observed between any dietary items and occurrence or type of plastic found. Load and potential ecological impact in the marine environment can be expected to increase concurrently with increasing plastic use and number and variety of plastic sources. Future studies are necessary to understand the impacts of plastic ingestion on this species. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Kelp gulls, Larus dominicanus (Aves: Laridae, breeding in Keller Peninsula, King George Island, Antarctic Peninsula

    Directory of Open Access Journals (Sweden)

    Joaquim O. Branco

    2009-09-01

    Full Text Available We examined the distribution, abundance and density of the Kelp Gull, Larus dominicanus (Lichtenstein, 1823, at Keller Peninsula on two occasions during the breeding season of 2007-2008 (once for incubation and once for chick stages and compared our results with previously published data. We present information on the number of eggs, incubation success, and initial development of L. dominicanus chicks in the studied sites. The abundance and density of the species has remained statistically similar in Keller Peninsula over the last 30 years (since 1978-1979. Although the abundance and density were almost unchanged, we recorded alterations in the occupation of the breeding areas by L. dominicanus, mainly the abandonment of breeding sites in the eastern portion of Keller Peninsula. The results of the present study compared with similar previous investigations on the abundance of L. dominicanus indicate that the populations have been in equilibrium over the years.

  20. Spatial and temporal variation in lead and cadmium in the Laughing Gull, Larus atricilla

    Energy Technology Data Exchange (ETDEWEB)

    Reid, M; Hacker, C S

    1982-11-01

    Lead and cadmium concentrations were measured in eggs and in bone, kidney, liver and stomach contents of downy young, prefledgling, and adult Laughing Gulls collected from Matagorda Bay and Galveston Bay, Texas. Matagorda Bay drains a rural, moderately industrialized region while the Galveston Bay area is heavily urbanized and industrialized. Lead levels were lower in birds from Matagorda Bay and decreased in birds from Galveston Bay between 1977 and 1980. Cadmium levels were also lower in birds from Matagorda Bay but increased over the three-year period in those from Galveston Bay. The temporal decrease in lead may be associated with such environmental control efforts as reduced point source emissions and substitution of unleaded gasoline.

  1. Molecular identification of erythrocytic necrosis virus (ENV) from the blood of Pacific herring (Clupea pallasii)

    Science.gov (United States)

    Emmenegger, Eveline J.; Glenn, Jolene A.; Winton, James R.; Batts, William N.; Gregg, Jacob L.; Hershberger, Paul K.

    2014-01-01

    Viral erythrocytic necrosis (VEN) is a condition affecting the red blood cells of more than 20 species of marine and anadromous fishes in the North Atlantic and North Pacific Oceans. Among populations of Pacific herring (Clupea pallasii) on the west coast of North America the disease causes anemia and elevated mortality in periodic epizootics. Presently, VEN is diagnosed by observation of typical cytoplasmic inclusion bodies in stained blood smears from infected fish. The causative agent, erythrocytic necrosis virus (ENV), is unculturable and a presumed iridovirus by electron microscopy. In vivo amplification of the virus in pathogen-free laboratory stocks of Pacific herring with subsequent virus concentration, purification, DNA extraction, and high-throughput sequencing were used to obtain genomic ENV sequences. Fragments with the highest sequence identity to the family Iridoviridae were used to design four sets of ENV-specific polymerase chain reaction (PCR) primers. Testing of blood and tissue samples from experimentally and wild infected Pacific herring as well as DNA extracted from other amphibian and piscine iridoviruses verified the assays were specific to ENV with a limit of detection of 0.0003 ng. Preliminary phylogenetic analyses of a 1448 bp fragment of the putative DNA polymerase gene supported inclusion of ENV in a proposed sixth genus of the family Iridoviridae that contains other erythrocytic viruses from ectothermic hosts. This study provides the first molecular evidence of ENV's inclusion within the Iridoviridae family and offers conventional PCR assays as a means of rapidly surveying the ENV-status of wild and propagated Pacific herring stocks.

  2. What can we learn from the stock collapse and recovery of North Sea herring? A review

    DEFF Research Database (Denmark)

    Dickey-Collas, M.; Nash, R.D.M.; Brunel, T.

    The collapse and recovery of North Sea herring in the latter half of the twentieth century hasbeen well documented. With hindsight and the benefit of almost 40 years of extra data andstudies, we can now obtain a clear view of the impact of the collapse and the recovery onthe stock, the fishery, a...... the relevant lessons for the management of other fish stocks and other marine shelf ecosystems...

  3. The use of photon correlation spectroscopy method for determining diffusion coefficient in brine and herring flesh

    Directory of Open Access Journals (Sweden)

    Shumanova M.V.

    2015-03-01

    Full Text Available The process fish salting has been studied by the method of photon correlation spectroscopy; the distribution of salt concentration in the solution and herring flesh with skin has been found, diffusion coefficients and salt concentrations used for creating a mathematical model of the salting technology have been worked out; the possibility of determination by this method the coefficient of dynamic viscosity of solutions and different media (minced meat etc. has been considered

  4. LIMNOLOGY, LAKE BASINS, LAKE WATERS

    Directory of Open Access Journals (Sweden)

    Petre GÂŞTESCU

    2009-06-01

    Full Text Available Limnology is a border discipline between geography, hydrology and biology, and is also closely connected with other sciences, from it borrows research methods. Physical limnology (the geography of lakes, studies lake biotopes, and biological limnology (the biology of lakes, studies lake biocoenoses. The father of limnology is the Swiss scientist F.A. Forel, the author of a three-volume entitled Le Leman: monographie limnologique (1892-1904, which focuses on the geology physics, chemistry and biology of lakes. He was also author of the first textbook of limnology, Handbuch der Seenkunde: allgemeine Limnologie,(1901. Since both the lake biotope and its biohydrocoenosis make up a single whole, the lake and lakes, respectively, represent the most typical systems in nature. They could be called limnosystems (lacustrine ecosystems, a microcosm in itself, as the American biologist St.A. Forbes put it (1887.

  5. Increased Wounding of Southern Right Whale (Eubalaena australis Calves by Kelp Gulls (Larus dominicanus at Península Valdés, Argentina.

    Directory of Open Access Journals (Sweden)

    Carina F Marón

    Full Text Available At least 626 southern right whale (Eubalaena australis calves died at the Península Valdés calving ground, Argentina, between 2003 and 2014. Intense gull harassment may have contributed to these deaths. In the 1970s, Kelp Gulls (Larus dominicanus began feeding on skin and blubber pecked from the backs of living right whales at Valdés. The frequency of gull attacks has increased dramatically over the last three decades and mother-calf pairs are the primary targets. Pairs attacked by gulls spend less time nursing, resting and playing than pairs not under attack. In successive attacks, gulls open new lesions on the whales' backs or enlarge preexisting ones. Increased wounding could potentially lead to dehydration, impaired thermoregulation, and energy loss to wound healing. The presence, number and total area of gull-inflicted lesions were assessed using aerial survey photographs of living mother-calf pairs in 1974-2011 (n = 2680 and stranding photographs of dead calves (n = 192 in 2003-2011. The percentage of living mothers and calves with gull lesions increased from an average of 2% in the 1970s to 99% in the 2000s. In the 1980s and 1990s, mothers and calves had roughly equal numbers of lesions (one to five, but by the 2000s, calves had more lesions (nine or more covering a greater area of their backs compared to their mothers. Living mother-calf pairs and dead calves in Golfo Nuevo had more lesions than those in Golfo San José in the 2000s. The number and area of lesions increased with calf age during the calving season. Intensified Kelp Gull harassment at Península Valdés could be compromising calf health and thereby contributing to the high average rate of calf mortality observed in recent years, but it cannot explain the large year-to-year variance in calf deaths since 2000.

  6. Kinetics of viral shedding provide insights into the epidemiology of viral hemorrhagic septicemia in Pacific herring

    Science.gov (United States)

    Hershberger, Paul K.; Gregg, Jacob L.; Winton, James R.; Grady, Courtney; Collins, Rachael

    2010-01-01

    Losses from infectious diseases are an important component of natural mortality among marine fish species, but factors controlling the ecology of these diseases and their potential responses to anthropogenic changes are poorly understood. We used viral hemorrhagic septicemia virus (VHSV) and a laboratory stock of Pacific herring Clupea pallasii to investigate the kinetics of viral shedding and its effect on disease transmission and host mortality. Outbreaks of acute disease, accompanied by mortality and viral shedding, were initiated after waterborne exposure of herring to concentrations of VHSV as low as 101 plaque-forming units (pfu) ml–1. Shed virus in flow-through tanks was first detected 4 to 5 d post-exposure, peaked after 6 to 10 d, and was no longer detected after 16 d. Shedding rates, calculated from density, flow and waterborne virus titer reached 1.8 to 5.0 × 108 pfu fish–1 d–1. Onset of viral shedding was dose-dependent and preceded initial mortality by 2 d. At 21 d, cumulative mortality in treatment groups ranged from 81 to 100% and was dependent not on challenge dose, but on the kinetics and level of viral shedding by infected fish in the tank. Possible consequences of the viral shedding and disease kinetics are discussed in the context of epizootic initiation and perpetuation among populations of wild Pacific herring.

  7. Persistence of external signs in Pacific herring Clupea pallasii Valenciennes with ichthyophoniasis

    Science.gov (United States)

    Hart, Lucas M.; Conway, Carla M.; Elliott, Diane G.; Hershberger, Paul K.

    2016-01-01

    The progression of external signs of Ichthyophonus infection in Pacific herring Clupea pallasii Valenciennes was highly variable and asynchronous after intraperitoneal injection with pure parasite preparations; however, external signs generally persisted through the end of the study (429 days post-exposure). Observed signs included papules, erosions and ulcers. The prevalence of external signs plateaued 35 days post-exposure and persisted in 73–79% of exposed individuals through the end of the first experiment (147 days post-exposure). Among a second group of infected herring, external signs completely resolved in only 10% of the fish after 429 days. The onset of mortality preceded the appearance of external signs. Histological examination of infected skin and skeletal muscle tissues indicated an apparent affinity of the parasite for host red muscle. Host responses consisted primarily of granulomatous inflammation, fibrosis and necrosis in the skeletal muscle and other tissues. The persistence and asynchrony of external signs and host response indicated that they were neither a precursor to host mortality nor did they provide reliable metrics for hindcasting on the date of exposure. However, the long-term persistence of clinical signs in Pacific herring may be useful in ascertaining the population-level impacts of ichthyophoniasis in regularly observed populations.

  8. Oogenesis, fecundity and condition of Baltic herring (Clupea harengus L.): A stereological study

    DEFF Research Database (Denmark)

    Bucholtz, R. Hagstrøm; Tomkiewicz, J.; Nyengaard, Jens Randel

    2013-01-01

    Herring (Clupea harengus) is a capital breeder that stores energy reserves in muscle tissue. Individual potential fecundity relies on the size and weight of female fish. Poor condition during the maturation process can lead to a heavy down-regulation of fecundity through atresia and, in the extre...... was a good predictor of potential fecundity within maturing stages of females. Combined with estimates of skipped spawning, this ovary weight could be used to estimate egg production thereby improving Central Baltic herring stock-recruitment models.......-regulation of fecundity. Although determined as spring spawners by otolith hatch type, 15% of the randomly sampled females were characterized by oocytes in CA stage in the prespawning period, indicating skipped spawning. The condition of these females was poor, which might have resulted in skipped spawning. Ovary weight......Herring (Clupea harengus) is a capital breeder that stores energy reserves in muscle tissue. Individual potential fecundity relies on the size and weight of female fish. Poor condition during the maturation process can lead to a heavy down-regulation of fecundity through atresia and, in the extreme...

  9. Quantitative determination of creatine kinase release from herring (Clupea harengus) spermatozoa induced by tributyltin.

    Science.gov (United States)

    Grzyb, Katarzyna; Rychłowski, Michał; Biegniewska, Anna; Skorkowski, Edward F

    2003-02-01

    Creatine kinase (CK, ATP creatine phosphotransferase, EC 2.7.3.2) is an enzyme participating in ATP regeneration, which is the primary source of energy in living organisms. We demonstrated that CK from herring spermatozoa has high activity ( approximately 452 micromol/min/g of fresh semen) and has a different electrophoretic mobility from isoenzymes present in skeletal muscle. In our study, we investigated toxic effect of tributyltin (TBT) on herring spermatozoa using a specific sperm viability kit to observe live and dead sperm cells with a confocal microscope. Treatment of herring spermatozoa with TBT caused a time-dependent decrease of viability: 35% nonviable cells with 5 microM TBT and more than 90% nonviable cells with 10 microM TBT after 6 h exposure. We also monitored CK release from damaged spermatozoa into surrounding medium containing different concentrations of TBT. The higher concentration of TBT was used the more CK release from spermatozoa was observed. We suggest that CK could be a good biomarker of sperm cell membranes degradation in the case when lactate dehydrogenase release from permeabilized cells is not possible for rapid determination of the effect of TBT.

  10. At-sea behavior varies with lunar phase in a nocturnal pelagic seabird, the swallow-tailed gull.

    Directory of Open Access Journals (Sweden)

    Sebastian M Cruz

    Full Text Available Strong and predictable environmental variability can reward flexible behaviors among animals. We used long-term records of activity data that cover several lunar cycles to investigate whether behavior at-sea of swallow-tailed gulls Creagrus furcatus, a nocturnal pelagic seabird, varied with lunar phase in the Galápagos Islands. A Bayesian hierarchical model showed that nighttime at-sea activity of 37 breeding swallow-tailed gulls was clearly associated with changes in moon phase. Proportion of nighttime spent on water was highest during darker periods of the lunar cycle, coinciding with the cycle of the diel vertical migration (DVM that brings prey to the sea surface at night. Our data show that at-sea behavior of a tropical seabird can vary with environmental changes, including lunar phase.

  11. At-sea behavior varies with lunar phase in a nocturnal pelagic seabird, the swallow-tailed gull

    Science.gov (United States)

    Cruz, Sebastian M.; Hooten, Mevin; Huyvaert, Kathryn P.; Proaño, Carolina B.; Anderson, David J.; Afanasyev, Vsevolod; Wikelski, Martin

    2013-01-01

    Strong and predictable environmental variability can reward flexible behaviors among animals. We used long-term records of activity data that cover several lunar cycles to investigate whether behavior at-sea of swallow-tailed gulls Creagrus furcatus, a nocturnal pelagic seabird, varied with lunar phase in the Galápagos Islands. A Bayesian hierarchical model showed that nighttime at-sea activity of 37 breeding swallow-tailed gulls was clearly associated with changes in moon phase. Proportion of nighttime spent on water was highest during darker periods of the lunar cycle, coinciding with the cycle of the diel vertical migration (DVM) that brings prey to the sea surface at night. Our data show that at-sea behavior of a tropical seabird can vary with environmental changes, including lunar phase.

  12. Egg production in a coastal seabird, the glaucous-winged gull (Larus glaucescens, declines during the last century.

    Directory of Open Access Journals (Sweden)

    Louise K Blight

    Full Text Available Seabirds integrate information about oceanic ecosystems across time and space, and are considered sensitive indicators of marine conditions. To assess whether hypothesized long-term foodweb changes such as forage fish declines may be reflected in a consumer's life history traits over time, I used meta-regression to evaluate multi-decadal changes in aspects of egg production in the glaucous-winged gull (Larus glaucescens, a common coastal bird. Study data were derived from literature searches of published papers and unpublished historical accounts, museum egg collections, and modern field studies, with inclusion criteria based on data quality and geographic area of the original study. Combined historical and modern data showed that gull egg size declined at an average of 0.04 cc y(-1 from 1902 (108 y, equivalent to a decline of 5% of mean egg volume, while clutch size decreased over 48 y from a mean of 2.82 eggs per clutch in 1962 to 2.25 in 2009. There was a negative relationship between lay date and mean clutch size in a given year, with smaller clutches occurring in years where egg laying commenced later. Lay date itself advanced over time, with commencement of laying presently (2008-2010 7 d later than in previous studies (1959-1986. This study demonstrates that glaucous-winged gull investment in egg production has declined significantly over the past ∼50-100 y, with such changes potentially contributing to recent population declines. Though gulls are generalist feeders that should readily be able to buffer themselves against food web changes, they are likely nutritionally constrained during the early breeding period, when egg production requirements are ideally met by consumption of high-quality prey such as forage fish. This study's results suggest a possible decline in the availability of such prey, and the incremental long-term impoverishment of a coastal marine ecosystem bordering one of North America's rapidly growing urban areas.

  13. Egg Production in a Coastal Seabird, the Glaucous-Winged Gull (Larus glaucescens), Declines during the Last Century

    Science.gov (United States)

    Blight, Louise K.

    2011-01-01

    Seabirds integrate information about oceanic ecosystems across time and space, and are considered sensitive indicators of marine conditions. To assess whether hypothesized long-term foodweb changes such as forage fish declines may be reflected in a consumer's life history traits over time, I used meta-regression to evaluate multi-decadal changes in aspects of egg production in the glaucous-winged gull (Larus glaucescens), a common coastal bird. Study data were derived from literature searches of published papers and unpublished historical accounts, museum egg collections, and modern field studies, with inclusion criteria based on data quality and geographic area of the original study. Combined historical and modern data showed that gull egg size declined at an average of 0.04 cc y−1 from 1902 (108 y), equivalent to a decline of 5% of mean egg volume, while clutch size decreased over 48 y from a mean of 2.82 eggs per clutch in 1962 to 2.25 in 2009. There was a negative relationship between lay date and mean clutch size in a given year, with smaller clutches occurring in years where egg laying commenced later. Lay date itself advanced over time, with commencement of laying presently (2008–2010) 7 d later than in previous studies (1959–1986). This study demonstrates that glaucous-winged gull investment in egg production has declined significantly over the past ∼50–100 y, with such changes potentially contributing to recent population declines. Though gulls are generalist feeders that should readily be able to buffer themselves against food web changes, they are likely nutritionally constrained during the early breeding period, when egg production requirements are ideally met by consumption of high-quality prey such as forage fish. This study's results suggest a possible decline in the availability of such prey, and the incremental long-term impoverishment of a coastal marine ecosystem bordering one of North America's rapidly growing urban areas. PMID

  14. Experimental infection of highly pathogenic avian influenza virus H5N1 in black-headed gulls (Chroicocephalus ridibundus).

    Science.gov (United States)

    Ramis, Antonio; van Amerongen, Geert; van de Bildt, Marco; Leijten, Loneke; Vanderstichel, Raphael; Osterhaus, Albert; Kuiken, Thijs

    2014-08-19

    Historically, highly pathogenic avian influenza viruses (HPAIV) rarely resulted in infection or clinical disease in wild birds. However, since 2002, disease and mortality from natural HPAIV H5N1 infection have been observed in wild birds including gulls. We performed an experimental HPAIV H5N1 infection of black-headed gulls (Chroicocephalus ridibundus) to determine their susceptibility to infection and disease from this virus, pattern of viral shedding, clinical signs, pathological changes and viral tissue distribution. We inoculated sixteen black-headed gulls with 1 × 10(4) median tissue culture infectious dose HPAIV H5N1 (A/turkey/Turkey/1/2005) intratracheally and intraesophageally. Birds were monitored daily until 12 days post inoculation (dpi). Oropharyngeal and cloacal swabs were collected daily to detect viral shedding. Necropsies from birds were performed at 2, 4, 5, 6, 7, and 12 dpi. Sampling from selected tissues was done for histopathology, immunohistochemical detection of viral antigen, PCR, and viral isolation. Our study shows that all inoculated birds were productively infected, developed systemic disease, and had a high morbidity and mortality rate. Virus was detected mainly in the respiratory tract on the first days after inoculation, and then concentrated more in pancreas and central nervous system from 4 dpi onwards. Birds shed infectious virus until 7 dpi from the pharynx and 6 dpi from the cloaca. We conclude that black-headed gulls are highly susceptible to disease with a high mortality rate and are thus more likely to act as sentinel species for the presence of the virus than as long-distance carriers of the virus to new geographical areas.

  15. Multi-laboratory evaluations of the performance of Catellicoccus marimammalium PCR assays developed to target gull fecal sources

    Science.gov (United States)

    Sinigalliano, Christopher D.; Ervin, Jared S.; Van De Werfhorst, Laurie C.; Badgley, Brian D.; Ballestée, Elisenda; Bartkowiaka, Jakob; Boehm, Alexandria B.; Byappanahalli, Muruleedhara N.; Goodwin, Kelly D.; Gourmelon, Michèle; Griffith, John; Holden, Patricia A.; Jay, Jenny; Layton, Blythe; Lee, Cheonghoon; Lee, Jiyoung; Meijer, Wim G.; Noble, Rachel; Raith, Meredith; Ryu, Hodon; Sadowsky, Michael J.; Schriewer, Alexander; Wang, Dan; Wanless, David; Whitman, Richard; Wuertz, Stefan; Santo Domingo, Jorge W.

    2013-01-01

    Here we report results from a multi-laboratory (n = 11) evaluation of four different PCR methods targeting the 16S rRNA gene of Catellicoccus marimammalium originally developed to detect gull fecal contamination in coastal environments. The methods included a conventional end-point PCR method, a SYBR® Green qPCR method, and two TaqMan® qPCR methods. Different techniques for data normalization and analysis were tested. Data analysis methods had a pronounced impact on assay sensitivity and specificity calculations. Across-laboratory standardization of metrics including the lower limit of quantification (LLOQ), target detected but not quantifiable (DNQ), and target not detected (ND) significantly improved results compared to results submitted by individual laboratories prior to definition standardization. The unit of measure used for data normalization also had a pronounced effect on measured assay performance. Data normalization to DNA mass improved quantitative method performance as compared to enterococcus normalization. The MST methods tested here were originally designed for gulls but were found in this study to also detect feces from other birds, particularly feces composited from pigeons. Sequencing efforts showed that some pigeon feces from California contained sequences similar to C. marimammalium found in gull feces. These data suggest that the prevalence, geographic scope, and ecology of C. marimammalium in host birds other than gulls require further investigation. This study represents an important first step in the multi-laboratory assessment of these methods and highlights the need to broaden and standardize additional evaluations, including environmentally relevant target concentrations in ambient waters from diverse geographic regions.

  16. Climate variability and temporal trends of persistent organic pollutants in the arctic: a study of glaucous gulls.

    Science.gov (United States)

    Bustnes, Jan O; Gabrielsen, Geir W; Verreault, Jonathan

    2010-04-15

    The impact of climate variability on temporal trends (1997-2006) of persistent organic pollutants (POPs; polychlorinated biphenyls [PCB], hexachlorobenzene [HCB], and oxychlordane) was assessed in glaucous gulls (Larus hyperboreus) breeding in the Norwegian Arctic (n = 240). The Arctic Oscillation (AO: an index of sea-level pressure variability in the Northern Hemisphere above 20 degrees N) with different time lags was used as a climate proxy. The estimated concentrations of POPs in glaucous gull blood/plasma declined substantially (16-60%) over the time period. Multiple regression analyses showed that the rates of decline for POPs were correlated to climate variation when controlling for potential confounding variables (sex and body condition). More specifically AO in the current winter showed negative associations with POP concentrations, whereas the relationships with AO measurements from the year preceding POP measurements (AO preceding summer and AO preceding winter) were positive. Hence, gulls had relatively higher POP concentrations in breeding seasons following years with high air transport toward the Arctic. Furthermore, the impact of AO appeared to be stronger for HCB, a relatively volatile compound with high transport potential, compared to heavy chlorinated PCB congeners. This study thus suggests that predicted climate change should be considered in assessments of future temporal trends of POPs in Arctic wildlife.

  17. Organohalogen contamination in breeding glaucous gulls from the Norwegian Arctic: Associations with basal metabolism and circulating thyroid hormones

    International Nuclear Information System (INIS)

    Verreault, Jonathan; Bech, Claus; Letcher, Robert J.; Ropstad, Erik; Dahl, Ellen; Gabrielsen, Geir W.

    2007-01-01

    Exposure to organohalogens in endotherms has been suggested to impose chemically induced stress by affecting functions related to maintenance energy requirements. Effects on basal metabolic rate (BMR) have been suggested to be, in part, mediated through interactions with the thyroid hormones (THs). We investigated the relationships between plasma concentrations of major organochlorines, PBDEs, hydroxylated (OH)- and methoxylated (MeO)-PBDEs and OH-PCBs, circulating TH levels and BMR in breeding glaucous gulls (Larus hyperboreus) from the Norwegian Arctic. Negative associations were found between BMR and concentrations of ΣPCB, ΣDDT and particularly Σchlordane, which combined made up 91% of the total contaminant burden. Levels of THs (thyroxine and triiodothyronine) were not associated significantly with variation of BMR or concentrations of any of the compounds determined. The present study suggests that BMR may be altered in glaucous gulls exposed to high loadings of persistent contaminants in the Norwegian Arctic environment. - Basal metabolic rate in glaucous gulls was negatively associated with plasma organochlorine concentrations, but not with circulating thyroid hormone levels

  18. The Kelp Gull as bioindicator of environmental chemicals in the Magellan region. A comparison with other coastal sites in Chile

    Directory of Open Access Journals (Sweden)

    Jacqueline Muñoz

    1999-12-01

    Full Text Available During the breeding seasons 1994/5 and 1995/6 we collected Kelp Gull (Larus dominicanus eggs from five locations in central to south Chile to study the contamination with mercury and organochlorine compounds. The sites were Algarrobo, Concepción, Maiquillahue Bay, Doña Sebastiana Island (Chalcao channel at Chiloé and Magdalena Island (Straits of Magellan. We found differences among the sites: Kelp Gull eggs from Chiloé and Algarrobo had the greatest concentrations of mercury (about 170 ng g-1 fresh weight. Residues of DDT were greatest in eggs from Algarrobo and Maiquillahue Bay, those of PCBs (polychlorinated biphenyls greatest at Algarrobo and Concepción. HCB had highest levels at Concepción. Considering all organochlorines, samples from Algarrobo had the highest concentrations, those from Chiloé the lowest. In consequence we found a geographical pattern from north to south, i.e., from areas with greater to lesser human impact. In comparison with other studies, the levels of environmental chemicals found in Kelp Gulls from Chile are much lower than those known to cause adverse effects on reproductive success.

  19. Fish waste as an alternative resource for gulls along the Patagonian coast: availability, use, and potential consequences

    Energy Technology Data Exchange (ETDEWEB)

    Yorio, Pablo; Caille, Guillermo

    2004-04-01

    We evaluated the volumes of waste from fish processing plants in Chubut Province, Argentina, and discuss its potential consequences for Kelp Gull (Larus dominicanus) population dynamics and coastal management. Mean volume of waste produced between 1989 and 2001 in three coastal cities was 49.8 {+-} 10.9 thousand tons y{sup -1}. The amount of waste varied between years and cities, being larger at Puerto Madryn and Comodoro Rivadavia than at Rawson (24.1, 19.3 and 6.4 thousand tons y{sup -1}, respectively). Waste was disposed at the three cities during all months of the sampled years. Large numbers of Kelp Gulls have been recorded taking advantage of fish waste disposed at these waste sites throughout the year. Considering its energetic content, waste generated at processing plants may support a population of between 101 000 and 209 000 Kelp Gulls. Fish waste could be contributing to their population expansion through increased survival and breeding success. Conflicts due to the use of waste and derived effects on other coastal species and human populations could be minimized by adequate fish waste management.

  20. Fish waste as an alternative resource for gulls along the Patagonian coast: availability, use, and potential consequences

    International Nuclear Information System (INIS)

    Yorio, Pablo; Caille, Guillermo

    2004-01-01

    We evaluated the volumes of waste from fish processing plants in Chubut Province, Argentina, and discuss its potential consequences for Kelp Gull (Larus dominicanus) population dynamics and coastal management. Mean volume of waste produced between 1989 and 2001 in three coastal cities was 49.8 ± 10.9 thousand tons y -1 . The amount of waste varied between years and cities, being larger at Puerto Madryn and Comodoro Rivadavia than at Rawson (24.1, 19.3 and 6.4 thousand tons y -1 , respectively). Waste was disposed at the three cities during all months of the sampled years. Large numbers of Kelp Gulls have been recorded taking advantage of fish waste disposed at these waste sites throughout the year. Considering its energetic content, waste generated at processing plants may support a population of between 101 000 and 209 000 Kelp Gulls. Fish waste could be contributing to their population expansion through increased survival and breeding success. Conflicts due to the use of waste and derived effects on other coastal species and human populations could be minimized by adequate fish waste management

  1. Fine-scale flight strategies of gulls in urban airflows indicate risk and reward in city living.

    Science.gov (United States)

    Shepard, Emily L C; Williamson, Cara; Windsor, Shane P

    2016-09-26

    Birds modulate their flight paths in relation to regional and global airflows in order to reduce their travel costs. Birds should also respond to fine-scale airflows, although the incidence and value of this remains largely unknown. We resolved the three-dimensional trajectories of gulls flying along a built-up coastline, and used computational fluid dynamic models to examine how gulls reacted to airflows around buildings. Birds systematically altered their flight trajectories with wind conditions to exploit updraughts over features as small as a row of low-rise buildings. This provides the first evidence that human activities can change patterns of space-use in flying birds by altering the profitability of the airscape. At finer scales still, gulls varied their position to select a narrow range of updraught values, rather than exploiting the strongest updraughts available, and their precise positions were consistent with a strategy to increase their velocity control in gusty conditions. Ultimately, strategies such as these could help unmanned aerial vehicles negotiate complex airflows. Overall, airflows around fine-scale features have profound implications for flight control and energy use, and consideration of this could lead to a paradigm-shift in the way ecologists view the urban environment.This article is part of the themed issue 'Moving in a moving medium: new perspectives on flight'. © 2016 The Author(s).

  2. Organohalogen contamination in breeding glaucous gulls from the Norwegian Arctic: Associations with basal metabolism and circulating thyroid hormones

    Energy Technology Data Exchange (ETDEWEB)

    Verreault, Jonathan [Norwegian Polar Institute, Polar Environmental Centre, NO-9296 Tromso (Norway) and Department of Aquatic BioSciences, University of Tromso, NO-9037 Tromso (Norway)]. E-mail: jonathan@npolar.no; Bech, Claus [Department of Biology, Norwegian University of Science and Technology, NO-7491 Trondheim (Norway); Letcher, Robert J. [Environment Canada, Canadian Wildlife Service, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3 (Canada); Ropstad, Erik [Department of Reproduction and Forensic Medicine, Norwegian School of Veterinary Science, P.O. Box 8146 Dep., NO-0033 Oslo (Norway); Dahl, Ellen [Department of Reproduction and Forensic Medicine, Norwegian School of Veterinary Science, P.O. Box 8146 Dep., NO-0033 Oslo (Norway); Gabrielsen, Geir W. [Norwegian Polar Institute, Polar Environmental Centre, NO-9296 Tromso (Norway)

    2007-01-15

    Exposure to organohalogens in endotherms has been suggested to impose chemically induced stress by affecting functions related to maintenance energy requirements. Effects on basal metabolic rate (BMR) have been suggested to be, in part, mediated through interactions with the thyroid hormones (THs). We investigated the relationships between plasma concentrations of major organochlorines, PBDEs, hydroxylated (OH)- and methoxylated (MeO)-PBDEs and OH-PCBs, circulating TH levels and BMR in breeding glaucous gulls (Larus hyperboreus) from the Norwegian Arctic. Negative associations were found between BMR and concentrations of {sigma}PCB, {sigma}DDT and particularly {sigma}chlordane, which combined made up 91% of the total contaminant burden. Levels of THs (thyroxine and triiodothyronine) were not associated significantly with variation of BMR or concentrations of any of the compounds determined. The present study suggests that BMR may be altered in glaucous gulls exposed to high loadings of persistent contaminants in the Norwegian Arctic environment. - Basal metabolic rate in glaucous gulls was negatively associated with plasma organochlorine concentrations, but not with circulating thyroid hormone levels.

  3. The GULLS project: a comparison of vulnerabilities across selected ocean hotspots and implications for adaptation to global change.

    Science.gov (United States)

    Cochrane, K.; Hobday, A. J.; Aswani, S.; Byfield, V.; Dutra, L.; Gasalla, M.; Haward, M.; Paytan, A.; Pecl, G.; Plaganyi-Lloyd, E.; Popova, K.; Salim, S. S.; Savage, C.; Sauer, W.; van Putten, I. E.; Visser, N.; Team, T G

    2016-12-01

    The GULLS project, `Global learning for local solutions: Reducing vulnerability of marine-dependent coastal communities' has been underway since October 2014. The project has been investigating six regional `hotspots': marine areas experiencing rapid warming. These are south-east Australia, Brazil, India, Solomon Islands, South Africa, and the Mozambique Channel and Madagascar. Rapid warming could be expected to have social, cultural and economic impacts that could affect these countries in different ways and may already be doing so. GULLS has focused on contributing to assessing and reducing the vulnerability of coastal communities and other stakeholders dependent on marine resources and to facilitate adaptation to climate change and variability through an integrated and trans-disciplinary approach. It includes participants from Australia, Brazil, India, Madagascar, New Zealand, South Africa, the United Kingdom and the United States of America. The research programme has been divided into six inter-linked components: ocean models, biological and ecological sensitivity analyses, system models, social vulnerability, policy mapping, and communication and education. This presentation will provide a brief overview of each of these components and describe the benefits that have resulted from the collaborative and transdisciplinary approach of GULLS. Following the standard vulnerability elements of exposure, sensitivity and adaptive capacity, the vulnerabilities of coastal communities and other stakeholders dependent on marine resources in the five hotspots will be compared using a set of indicators derived and populated from results of the research programme. The implications of similarities and differences between the hotspots for adaptation planning and options will be described.

  4. Lake sediments as natural seismographs: Earthquake-related deformations (seismites) in central Canadian lakes

    Science.gov (United States)

    Doughty, M.; Eyles, N.; Eyles, C. H.; Wallace, K.; Boyce, J. I.

    2014-11-01

    Central Canada experiences numerous intraplate earthquakes but their recurrence and source areas remain obscure due to shortness of the instrumental and historic records. Unconsolidated fine-grained sediments in lake basins are 'natural seismographs' with the potential to record ancient earthquakes during the last 10,000 years since the retreat of the Laurentide Ice Sheet. Many lake basins are cut into bedrock and are structurally-controlled by the same Precambrian basement structures (shear zones, terrane boundaries and other lineaments) implicated as the source of ongoing mid-plate earthquake activity. A regional seismic sub-bottom profiling of lakes Gull, Muskoka, Joseph, Rousseau, Ontario, Wanapitei, Fairbanks, Vermilion, Nipissing, Georgian Bay, Mazinaw, Simcoe, Timiskaming, Kipawa, Parry Sound and Lake of Bays, encompassing a total of more than 2000 kilometres of high-resolution track line data supplemented by multibeam and sidescan sonar survey records show a consistent sub-bottom stratigraphy of relatively-thick lowermost lateglacial facies composed of interbedded semi-transparent mass flow facies (debrites, slumps) and rhythmically-laminated silty-clays. Mass flows together with cratered ('kettled') lake floors and associated deformations reflect a dynamic ice-contact glaciolacustrine environment. Exceptionally thick mass flow successions in Lake Timiskaming along the floor of the Timiskaming Graben within the seismically-active Western Quebec Seismic Zone (WQSZ), point to a higher frequency of earthquakes and slope failure during deglaciation and rapid glacio-isostatic rebound though faulting continues into the postglacial. Lateglacial faulting, diapiric deformation and slumping of coeval lateglacial sediments is observed in Parry Sound, Lake Muskoka and Lake Joseph, which are all located above prominent Precambrian terrane boundaries. Lateglacial sediments are sharply overlain by relatively-thin rhythmically-laminated and often semi

  5. Small scale distribution patterns and vertical migration of North Sea herring larvae (Clupea harengus, Teleostei: Clupeidea in relation to abiotic and biotic factors

    Directory of Open Access Journals (Sweden)

    Holger Haslob

    2009-10-01

    Full Text Available The distribution of herring larvae in relation to environmental conditions and the occurrence of possible prey and predator organisms was studied during a 4-day period on a permanent station in the northern North Sea in September 1999. The vertical distribution of herring larvae was sampled in 20-m intervals by means of a multiple-closing net. To resolve the small-scale patchiness of herring larvae and planktonic prey and predator organisms, a towed in-situ video system was used, the Ichthyoplankton Recorder. A diel vertical migration of herring larvae was observed with different intensities depending on their body length. Small larvae ( 16 mm showed the highest abundances in the upper water layers during the day and were concentrated in deeper water layers during the night. The presented results appear to be relevant for individual-based modelling of the fate of larval herring populations.

  6. Broad-scale climate influences on spring-spawning herring (Clupea harengus, L.) recruitment in the Western Baltic Sea.

    Science.gov (United States)

    Gröger, Joachim P; Hinrichsen, Hans-Harald; Polte, Patrick

    2014-01-01

    Climate forcing in complex ecosystems can have profound implications for ecosystem sustainability and may thus challenge a precautionary ecosystem management. Climatic influences documented to affect various ecological functions on a global scale, may themselves be observed on quantitative or qualitative scales including regime shifts in complex marine ecosystems. This study investigates the potential climatic impact on the reproduction success of spring-spawning herring (Clupea harengus) in the Western Baltic Sea (WBSS herring). To test for climate effects on reproduction success, the regionally determined and scientifically well-documented spawning grounds of WBSS herring represent an ideal model system. Climate effects on herring reproduction were investigated using two global indices of atmospheric variability and sea surface temperature, represented by the North Atlantic Oscillation (NAO) and the Atlantic Multi-decadal Oscillation (AMO), respectively, and the Baltic Sea Index (BSI) which is a regional-scale atmospheric index for the Baltic Sea. Moreover, we combined a traditional approach with modern time series analysis based on a recruitment model connecting parental population components with reproduction success. Generalized transfer functions (ARIMAX models) allowed evaluating the dynamic nature of exogenous climate processes interacting with the endogenous recruitment process. Using different model selection criteria our results reveal that in contrast to NAO and AMO, the BSI shows a significant positive but delayed signal on the annual dynamics of herring recruitment. The westward influence of the Siberian high is considered strongly suppressing the influence of the NAO in this area leading to a higher explanatory power of the BSI reflecting the atmospheric pressure regime on a North-South transect between Oslo, Norway and Szczecin, Poland. We suggest incorporating climate-induced effects into stock and risk assessments and management strategies as part

  7. Broad-scale climate influences on spring-spawning herring (Clupea harengus, L. recruitment in the Western Baltic Sea.

    Directory of Open Access Journals (Sweden)

    Joachim P Gröger

    Full Text Available Climate forcing in complex ecosystems can have profound implications for ecosystem sustainability and may thus challenge a precautionary ecosystem management. Climatic influences documented to affect various ecological functions on a global scale, may themselves be observed on quantitative or qualitative scales including regime shifts in complex marine ecosystems. This study investigates the potential climatic impact on the reproduction success of spring-spawning herring (Clupea harengus in the Western Baltic Sea (WBSS herring. To test for climate effects on reproduction success, the regionally determined and scientifically well-documented spawning grounds of WBSS herring represent an ideal model system. Climate effects on herring reproduction were investigated using two global indices of atmospheric variability and sea surface temperature, represented by the North Atlantic Oscillation (NAO and the Atlantic Multi-decadal Oscillation (AMO, respectively, and the Baltic Sea Index (BSI which is a regional-scale atmospheric index for the Baltic Sea. Moreover, we combined a traditional approach with modern time series analysis based on a recruitment model connecting parental population components with reproduction success. Generalized transfer functions (ARIMAX models allowed evaluating the dynamic nature of exogenous climate processes interacting with the endogenous recruitment process. Using different model selection criteria our results reveal that in contrast to NAO and AMO, the BSI shows a significant positive but delayed signal on the annual dynamics of herring recruitment. The westward influence of the Siberian high is considered strongly suppressing the influence of the NAO in this area leading to a higher explanatory power of the BSI reflecting the atmospheric pressure regime on a North-South transect between Oslo, Norway and Szczecin, Poland. We suggest incorporating climate-induced effects into stock and risk assessments and management

  8. Intra population polymorphism of Caspian gull (Larus cachinnans from the North-Western Coast of the Azov Sea (oological aspect

    Directory of Open Access Journals (Sweden)

    Y. Y. Dubinina

    2016-03-01

    Full Text Available This study presents the results of a long term study of nesting colonies of the Caspian gull (Larus cachinnans Pallas, 1811 on the islands of the Molochniy Liman and in Obitochnaya Bay (Azov Sea, in the South of Ukraine (Zaporizhia region, conducted between 1988 and 2013. A description of the size and coloring of eggs of Caspian gull was conducted by generally accepted methods. We measured 1000 eggs from 5 colonies of Caspian gulls. The background coloration of the eggs’ shells was classified into 7 types, the pattern of markings on the surface of the shells was classified into 4 types. In the nesting colonies, comprising different nesting settlements, the study tested differences in the distribution of typical and atypical coloring types and patterns on the surface of the shells. The background color and character of the shell marking patterns is dominated by eggs of phenotypes 3 and 4: gray-green, with a pattern of spots, of medium size (5–60% and brown, with a pattern of large spots (2–40%. In different settlements the Caspian gull egg sizes vary in length and diameter of 54.5–86.3 x 39.2–60.4 mm, volume 61.7–113.7 cm3 and index of roundness 63.6–85.3%. The study revealed that the linear dimensions of eggs also depend on the number of birds in the nesting colonies. We found that morphological and dimensional characteristics of Caspian gull eggs can vary at certain intervals and characterize individual colonies, settlements and populations. Based on cluster analysis, conducted in terms of the average of the linear sizes of eggs of Caspian gull from several populations within the range of the species, the study identified three groups of colonies – Danube-Sivash, Azov-Black Sea and Caucasus-Caspian. In region of the Azov-Black Sea, the greatest similarity was shown between the settlements of Sivash and the South of Crimea, which in turn is similar to Lebiyazhyi Islands and Kaniv Nature Reserve (river Dnipro. A related link

  9. Membrane fractionation of herring marinade for separation and recovery of fats, proteins, amino acids, salt, acetic acid and water

    DEFF Research Database (Denmark)

    Fjerbæk Søtoft, Lene; Lizarazu, Juncal Martin; Razi Parjikolaei, Behnaz

    2015-01-01

    In the production of marinated herring, nearly one ton of acidic saline marinade is produced per 1.5 tons herring fillet. This spent marinade contains highly valuable compounds such as proteins and amino acids. Membranes are suited to recover these substances. In this work, six membrane stages...... containing sugars, amino acids and smaller peptides and a NF permeate containing salt and acetic acid ready for reuse. 42% of the spent marinade is recovered to substitute fresh water and chemicals. The Waste water amount is reduced 62.5%. Proteins are concentrated 30 times, while amino acids and smaller...

  10. An Ichthyophonus hoferi epizootic in herring in the North Sea, the Skagerrak, the Kattegat and the Baltic Sea

    OpenAIRE

    Mellergaard, Stig; Spanggaard, Bettina

    1997-01-01

    An epizootic caused by the internal parasite Ichthyophonus hoferi in herring Clupea harengus was recorded from 1991 to 1993 in the waters around Denmark. A surveillance programme from research vessels and commercial fishing boats was conducted in the North Sea, Skagerrak, Kattegat and Baltic Sea. A total of 15769 hearts of adult herring were examined macroscopically for evidence of infection. The prevalence of the infection in this period decreased from 10.6 to 2.0% in the North Sea, from 8.0...

  11. Hypoxia increases the behavioural activity of schooling herring: a response to physiological stress or respiratory distress?

    DEFF Research Database (Denmark)

    Herbert, Neill A.; Steffensen, John F.

    2006-01-01

    a deviation in physiological homeostasis is associated with any change in behavioural activity, we exposed C. harengus in a school to a progressive stepwise decline in water oxygen pressure  and measured fish swimming speed and valid indicators of primary and secondary stress (i.e. blood cortisol, lactate......Atlantic herring, Clupea harengus, increase their swimming speed during low O2 (hypoxia) and it has been hypothesised that the behavioural response is modulated by the degree of "respiratory distress" (i.e. a rise in anaerobic metabolism and severe physiological stress). To test directly whether...

  12. Modelling the mixing of herring stocks between the Baltic and the North Sea from otolith data

    DEFF Research Database (Denmark)

    Ulrich, Clara; Post, Søren Lorentzen; Worsøe Clausen, Lotte

    2012-01-01

    and Swedish commercial landings and surveys samples for the purpose of stock assessment. But the split estimates from sampling data are highly variable and noisy. Better understanding of the migration and exploitation patterns involved could therefore potentially improve the stock assessment as well...... and are consistent with existing ideas about the migration patterns of WBSS and NSAS within Division IIIa and adjacent waters. This work therefore provides the foundation for the development of a more rational management of the herring stocks in this area...

  13. Predictions of realised fecundity and spawning time in Norwegian spring-spawning herring ( Clupea harengus)

    Science.gov (United States)

    Óskarsson, G. J.; Kjesbu, O. S.; Slotte, A.

    2002-08-01

    Maturing Norwegian spring-spawning (NSS) herring, Clupea harengus, were collected for reproductive analyses along the Norwegian coast prior to the spawning seasons of 1997-2000. Over this time period there was a marked change in weight (W) at length (TL) with 1998 showing extremely low values and 2000 high values in a historical perspective. Potential fecundity, amounting to about 20 000-100 000 developing (vitellogenic) oocytes per fish and positively related to fish size, increased significantly with fish condition. Relative somatic potential fecundity (RF P, number of oocytes per g ovary-free body weight) in NSS herring was found to vary by 35-55% between years. Unexpectedly, females in 2000 showed low RF P-values, possibly due to negative feedback from previous reproductive investments at low condition. A clear threshold value for Fulton's condition factor, K (K=100×W/TL 3), of 0.65-0.70 existed below which there was considerable atresia (resorption of vitellogenic oocytes). Thus, these components of the spawning stock, amounting to 1-46% in the period 1980-1999, obviously contributed relatively little to the total egg production. This was confirmed by low ovary weights and examples of delayed oocyte development in these individuals. An up-to-date atresia model is presented. The established oocyte growth curve, and to a lesser degree the assumed atretic oocytic turnover rate, was critical for the estimation of realised fecundity (number of eggs spawned). Modelled realised fecundity was significantly below observed potential fecundity. Females that had migrated the shortest distance from the over-wintering area, Vestfjorden, northern Norway, were in the poorest condition, had the least developed oocytes and the lowest potential and realised fecundities. In agreement with previously published studies on temporal and spatial changes in gonad weights, those females reaching the main spawning grounds in the south-western part of the coast (Møre) were the most

  14. Sexual differences in post-hatching Saunders's gulls: size, locomotor activity, and foraging skill.

    Science.gov (United States)

    Yoon, Jongmin; Lee, Seung-Hee; Joo, Eun-Jin; Na, Ki-Jeong; Park, Shi-Ryong

    2013-04-01

    Various selection pressures induce the degree and direction of sexual size dimorphism in animals. Selection favors either larger males for contests over mates or resources, or smaller males are favored for maneuverability; whereas larger females are favored for higher fecundity, or smaller females for earlier maturation for reproduction. In the genus of Larus (seagulls), adult males are generally known to be larger in size than adult females. However, the ontogeny of sexual size dimorphism is not well understood, compared to that in adults. The present study investigates the ontogeny of sexual size dimorphism in Saunders's gulls (Larus saundersi) in captivity. We artificially incubated fresh eggs collected in Incheon, South Korea, and measured body size, locomotor activity, and foraging skill in post-hatching chicks in captivity. Our results indicated that the sexual differences in size and locomotor activity occurred with the post-hatching development. Also, larger males exhibited greater foraging skills for food acquisition than smaller females at 200 days of age. Future studies should assess how the adaptive significance of the sexual size dimorphism in juveniles is linked with sexual divergence in survival rates, intrasexual contests, or parental effort in sexes.

  15. Growth of Audouin's gull chicks: the role of prehatch and posthatch factors

    Directory of Open Access Journals (Sweden)

    Elena Villuendas

    2003-07-01

    Full Text Available We compared the growth rates of Audouin´s Gull (Larus audouinii chicks from the Ebro Delta and Columbretes Islands. Chicks from the Columbretes Islands were reared in captivity and fed ad libitum. Wild chicks from the Ebro Delta weighed more than chicks hatched from Columbretes eggs but attained a lower weight at fledging. Chicks from Columbretes eggs hatched with a longer wing length but rates did not differ between samples during the early stages of growth. Eggs from the Ebro Delta were significantly larger than eggs from Columbretes. Hence, differences in growth appeared not to be related to differences in egg size (prehatch factor but only in parental quality (posthatch factor through the amount of food delivered to chicks. These differences could be due to the incapacity of parents to provide enough food during the last stages of chick development, in part because of reduced food availability at the Ebro Delta during the study period. Alternatively, differences could be attributed to a trade-off between present and future reproduction. Demographic consequences of reduced food availability for the 1993 Ebro Delta cohort should be explored in future work.

  16. Artificial propagation of coregonines in the management of the Laurentian Great Lakes

    Science.gov (United States)

    Todd, Thomas N.

    1986-01-01

    Numerous stresses caused wide fluctuations in the abundance of Great Lakes coregonine fishes during the last century. State, Provincial, and Federal agencies attempted to bolster these fisheries by stocking more than 32 billion fry of lake whitefish (Coregonus clupeaformis) and 6 billion fry of lake herring (C. artedii) over a period of about 90 years (1870-1960). Propagation efforts were unsuccessful in arresting the decline of these fishes, perhaps because the stocking densities were too low. It appears that stocking densities must exceed 41% of the natural hatch to produce measurable success in a planting program that augments natural reproduction. Stocking of any of the Great Lakes with lake whitefish at these levels would require several billion fry per lake annually. Such a program is too large to be practical and intensified protection of the remaining stocks would be more cost effective. A species such as the shortnose cisco (C. reighardi) which has only a small number of extant individuals, and can therefore be significantly augmented with fewer stocked fish, may be a much better candidate for propagation than is the lake whitefish. Propagation of coregonines in the Great Lakes should be considered only in localities that have little or no natural recruitment and then only for rehabilitation, and only if accompanied by adequate assessment of the performance of the stocked fish.

  17. Loss of vitamin B(12) in fish (round herring) meats during various cooking treatments.

    Science.gov (United States)

    Nishioka, Michiko; Kanosue, Fuki; Yabuta, Yukinori; Watanabe, Fumio

    2011-01-01

    The loss of vitamin B(12) in round herring meats during various cooking treatments was evaluated. Although amounts of vitamin B(12) were three times greater in the viscera (37.5 ± 10.6 µg/100 g fresh weight) than in the meats, about 73% of total vitamin B(12) found in the whole fish body (except for head and bones) were recovered in the meats (5.1 ± 1.0 µg of vitamin B(12)). The vitamin B(12) contents of the round herring's meats were significantly decreased up to ~62% during cooking by grilling, boiling, frying, steaming, and microwaving. There was, however, no loss of vitamin B(12) during vacuum-packed pouch cooking. Model experiment using hydroxocobalamin suggest that loss of vitamin B(12) is dependent on the degree of temperature and time used in conventional cooking, and is further affected by the concomitant ingredients of food. Retention of vitamin B(12) was not dependent on vacuum or temperature (or both) used in the vacuum-packed pouch cooking.

  18. Seagulls (Larus spp.) as vectors of salmonellae: an investigation into the range of serotypes and numbers of salmonellae in gull faeces.

    Science.gov (United States)

    Fenlon, D R

    1981-04-01

    Of 1241 samples of seagulls faeces examined, 12.9% were found to contain salmonellae. The number of positive samples was significantly higher (17-21%) near sewage outfalls. Twenty-seven serotypes were isolated, including a new serotype named Salmonella grampian. The range and frequency of serotypes carried by gulls was similar to those in the human population, suggesting sewage as a possible source of gull infection. The number of salmonellae found in positive samples was low (0.18-191 g-1 faeces). This was similar to the numbers found in sewage, 10-80 1-1, suggesting gulls may only carry infected material without infecting themselves. Antibiotic resistance in the isolates was low, only 21 showing resistance to the antibiotics tested, although most of these were determined by resistance transfer plasmids.

  19. Larval and juvenile Pacific herring Clupea pallasii are not susceptible to infectious hematopoietic necrosis under laboratory conditions

    Science.gov (United States)

    Hart, L.M.; Traxler, G.S.; Garver, K.A.; Richard, J.; Gregg, J.L.; Grady, C.A.; Kurath, G.; Hershberger, P.K.

    2011-01-01

    Infectious hematopoietic necrosis (IHN) leads to periodic epidemics among certain wild and farmed fish species of the Northeast (NE) Pacific. The source of the IHN virus (IHNV) that initiates these outbreaks remains unknown; however, a leading hypothesis involves viral persistence in marine host species such as Pacific herring Clupea pallasii. Under laboratory conditions we exposed specific pathogen-free (SPF) larval and juvenile Pacific herring to 103 to 104 plaque-forming units (pfu) of IHNV ml–1 by waterborne immersion. Cumulative mortalities among exposed groups were not significantly different from those of negative control groups. After waterborne exposure, IHNV was transiently recovered from the tissues of larvae but absent in tissues of juveniles. Additionally, no evidence of viral shedding was detected in the tank water containing exposed juveniles. After intraperitoneal (IP) injection of IHNV in juvenile herring with 103 pfu, IHNV was recovered from the tissues of sub-sampled individuals for only the first 5 d post-exposure. The lack of susceptibility to overt disease and transient levels of IHNV in the tissues of exposed fish indicate that Pacific herring do not likely serve a major epizootiological role in perpetuation of IHNV among free-ranging sockeye salmon Oncorhynchus nerka and farmed Atlantic salmon Salmo salar in the NE Pacific.

  20. Coupling otolith microstructure analysis and hydrographic backtracking suggests a mechanism for the 2000s North Sea herring recruitment failure

    DEFF Research Database (Denmark)

    Ross, Stine Dalmann; Payne, Mark; Worsøe Clausen, Lotte

    2012-01-01

    The North Sea autumn spawning herring (Clupea harengus) has, since the 2002 year class, shown an unprecedented sequence of ten years of sharply reduced recruitment, in spite of a high spawning biomass and low fishing mortality. Recent work has identified this reduction in recruitment level (or st...

  1. Characterization of herring populations west of the British Isles: an investigation of mixing based on otolith microchemistry

    NARCIS (Netherlands)

    Geffen, A.J.; Nash, R.D.M.; Dickey-Collas, M.

    2011-01-01

    Herring along the west coast of the British Isles are managed and assessed as a series of discrete stocks. The relationship between the spawning components, mixed (feeding) aggregations, and juveniles in nursery areas for these stocks was modelled by discriminant analysis and integrated stock

  2. Regional and seasonal differences in growth of larval North Sea herring (clupea harengus L.) estimated by otolith microstructure analysis

    DEFF Research Database (Denmark)

    Munk, Peter; Heath, Mike; Skaarup, Bo

    1991-01-01

    The ecology processes of the larval life of autumn-spawned North Sea herring have been studied in a multidisciplinary and internationally coordinated research programme (ACE). The programme focused on larval advection and the importance of the autumn/winter circulation in determining larval distr...

  3. What is left? Macrophyte meadows and Atlantic herring (Clupea harengus) spawning sites in the Greifswalder Bodden, Baltic Sea

    Science.gov (United States)

    Kanstinger, Philipp; Beher, Jutta; Grenzdörffer, Görres; Hammer, Cornelius; Huebert, Klaus B.; Stepputis, Daniel; Peck, Myron A.

    2018-02-01

    Coastal zones are productive areas of marine ecosystems which are also hotspots of anthropogenic activities causing habitat degradation. In the southwest Baltic Sea, eutrophication is thought to have caused the massive reduction in submerged macrophytes observed in recent decades. Here, we surveyed the submarine vegetation and examined locations of spawning of herring (Clupea harengus) in the Greifswalder Bodden, one of the most important reproductive habitats of the Western Baltic Spring Spawner herring stock (WBSS). This stock deposits eggs onto submerged vegetation and changes in macrophyte coverage are expected to influence the availability of reproductive habitat. Aerial, underwater video tows and SCUBA surveys conducted in spring 2009 revealed that only ∼7% of the lagoon was vegetated. Herring eggs were observed on 12 of 32 SCUBA transects, at depths between 0.2 and 5 m and were attached to a variety of spermatophyte and algae species but not to stones or mussels. A classification tree model indicated that spawning sites were strongly associated with the vegetation cover within a 100- and 500-m radius, implying that herring schools preferentially spawn on dense and large underwater meadows. Only ∼5% of the lagoon now falls into this vegetation category. Despite 20 years of efforts to reduce eutrophication, no increase in macroalgae and spermatophyte vegetation towards the historical level of 90% coverage in the area is apparent.

  4. Effects of temperature and population density on von Bertalanffy growth parameters in Atlantic herring: a macro-ecological analysis

    NARCIS (Netherlands)

    Brunel, T.P.A.; Dickey-Collas, M.

    2010-01-01

    The effect of temperature and population density on the growth of Atlantic herring Clupea harengus was studied using a comparative approach applied to 15 North Atlantic populations. The von Bertalanffy (VB) equation was applied to describe mean growth of individuals in each population, both averaged

  5. Microbiological quality of maatjes herring stored in air and under modified atmosphere at 4 and 10 C

    NARCIS (Netherlands)

    Lyhs, U.; Lahtinen, J.; Schelvis-Smit, A.A.M.

    2007-01-01

    Microbiological and sensory changes of maatjes herring stored in air (experiment I) and under modified atmosphere (MAP) (experiments II and III) were evaluated during storage at 4 and 10 °C. Microbial (total and psychrotrophic viable bacteria, lactic acid bacteria and Enterobacteriaceae) counts and

  6. Subchronic toxicity of Baltic herring oil and its fractions in the rat II: Clinical observations and toxicological parameters

    NARCIS (Netherlands)

    Stern, N.H.; Oberg, M.; Casabona, H.; Trossvik, C.; Manzoor, E.; Johansson, N.; Lind, M.; Orberg, J.; Feinstein, R.; Johansson, A.; Chu, I.; Poon, R.; Yagminas, A.; Brouwer, A.; Jones, B.; Hakansson, H.

    2002-01-01

    This study aimed to increase the knowledge about the toxicity of fish-derived organohalogen pollutants in mammals. The strategy chosen was to separate organohalogen pollutants derived from Baltic herring (Clupea harengus) fillet, in order to obtain fractions with differing proportions of identified

  7. An Ichthyophonus hoferi epizootic in herring in the North Sea, the Skagerrak, the Kattegat and the Baltic Sea

    DEFF Research Database (Denmark)

    Mellergaard, Stig; Spanggaard, Bettina

    1997-01-01

    An epizootic caused by the internal parasite Ichthyophonus hoferi in herring Clupea harengus was recorded from 1991 to 1993 in the waters around Denmark. A surveillance programme from research vessels and commercial fishing boats was conducted in the North Sea, Skagerrak, Kattegat and Baltic Sea...

  8. Lake Cadagno

    DEFF Research Database (Denmark)

    Tonolla, Mauro; Storelli, Nicola; Danza, Francesco

    2017-01-01

    Lake Cadagno (26 ha) is a crenogenic meromictic lake located in the Swiss Alps at 1921 m asl with a maximum depth of 21 m. The presence of crystalline rocks and a dolomite vein rich in gypsum in the catchment area makes the lake a typical “sulphuretum ” dominated by coupled carbon and sulphur...... cycles. The chemocline lies at about 12 m depth, stabilized by density differences of salt-rich water supplied by sub-aquatic springs to the monimolimnion and of electrolyte-poor surface water feeding the mixolimnion. Steep sulphide and light gradients in the chemocline support the growth of a large...... in the chemocline. Small-celled PSB together with the sulfate-reducing bacterium Desulfocapsa thiozymogenes sp. form stable aggregates in the lake, which represent small microenvironments with an internal sulphur cycle. Eukaryotic primary producers in the anoxic zones are dominated by Cryptomonas phaseolus...

  9. Playa Lakes

    Data.gov (United States)

    Kansas Data Access and Support Center — This digital dataset provides information about the spatial distribution of soil units associated with playa lakes. Specific soil types have been designated by the...

  10. Recurrent hybridization and recent origin obscure phylogenetic relationships within the ‘white-headed’ gull (Larus sp.) complex

    Science.gov (United States)

    Sonsthagen, Sarah A.; Wilson, Robert E.; Chesser, Terry; Pons, Jean-Marc; Crochet, Pierre-Andre; Driscoll, Amy; Dove, Carla

    2016-01-01

    Species complexes that have undergone recent radiations are often characterized by extensive allele sharing due to recent ancestry and (or) introgressive hybridization. This can result in discordant evolutionary histories of genes and heterogeneous genomes, making delineating species limits difficult. Here we examine the phylogenetic relationships among a complex group of birds, the white-headed gulls (Aves: Laridae), which offer a unique window into the speciation process due to their recent evolutionary history and propensity to hybridize. Relationships were examined among 17 species (61 populations) using a multilocus approach, including mitochondrial and nuclear intron DNA sequences and microsatellite genotype information. Analyses of microsatellite and intron data resulted in some species-based groupings, although most species were not represented by a single cluster. Considerable allele and haplotype sharing among white-headed gull species was observed; no locus contained a species-specific clade. Despite this, our multilocus approach provided better resolution among some species than previous studies. Interestingly, most clades appear to correspond to geographic locality: our BEAST analysis recovered strong support for a northern European/Icelandic clade, a southern European/Russian clade, and a western North American/canus clade, with weak evidence for a high latitude clade spanning North America and northwestern Europe. This geographical structuring is concordant with behavioral observations of pervasive hybridization in areas of secondary contact. The extent of allele and haplotype sharing indicates that ecological and sexual selection are likely not strong enough to complete reproductive isolation within several species in the white-headed gull complex. This suggests that just a few genes are driving the speciation process.

  11. Gene expression, glutathione status and indicators of hepatic oxidative stress in laughing gull (Larus atricilla) hatchlings exposed to methylmercury

    Science.gov (United States)

    Jenko, Kathryn; Karouna-Renier, Natalie K.; Hoffman, David J.

    2012-01-01

    Despite extensive studies of methylmercury (MeHg) toxicity in birds, molecular effects on birds are poorly characterized. To improve our understanding of toxicity pathways and identify novel indicators of avian exposure to Hg, the authors investigated genomic changes, glutathione status, and oxidative status indicators in liver from laughing gull (Larus atricilla) hatchlings that were exposed in ovo to MeHg (0.05–1.6 µg/g). Genes involved in the transsulfuration pathway, iron transport and storage, thyroid-hormone related processes, and cellular respiration were identified by suppression subtractive hybridization as differentially expressed. Quantitative polymerase chain reaction (qPCR) identified statistically significant effects of Hg on cytochrome C oxidase subunits I and II, transferrin, and methionine adenosyltransferase RNA expression. Glutathione-S-transferase activity and protein-bound sulfhydryl levels decreased, whereas glucose-6-phosphate dehydrogenase activity increased dose-dependently. Total sulfhydryl concentrations were significantly lower at 0.4 µg/g Hg than in controls. T ogether, these endpoints provided some evidence of compensatory effects, but little indication of oxidative damage at the tested doses, and suggest that sequestration of Hg through various pathways may be important for minimizing toxicity in laughing gulls. This is the first study to describe the genomic response of an avian species to Hg. Laughing gulls are among the less sensitive avian species with regard to Hg toxicity, and their ability to prevent hepatic oxidative stress may be important for surviving levels of MeHg exposures at which other species succumb.

  12. Herring and chicken/pork meals lead to differences in plasma levels of TCA intermediates and arginine metabolites in overweight and obese men and women

    DEFF Research Database (Denmark)

    Vincent, Andrew; Savolainen, Otto I; Sen, Partho

    2017-01-01

    citrate, fumarate, isocitrate, glycolate, oxalate, agmatine and methyhistidine and increased asparagine, ornithine, glutamine and the hexosamine glucosamine. Modelling found that the tricarboxylic acid cycle, glyoxylate, and argininemetabolism were affected by the intervention. The effect on arginine...... metabolism was supported by an increase in blood nitric oxide in males on the herring diet. Conclusion: The results suggest that eating herring instead of chicken and lean pork leads to important metabolic effects, particularly on energy and amino acid metabolism. Our findings support the hypothesis...... that there are metabolic effects of herring intake unrelated to the long chain n-3 polyunsaturated fatty acid content....

  13. Feeding Ecology of Northeast Atlantic Mackerel, Norwegian Spring-Spawning Herring and Blue Whiting in the Norwegian Sea.

    Directory of Open Access Journals (Sweden)

    Eneko Bachiller

    Full Text Available The Norwegian spring-spawning (NSS herring (Clupea harengus, blue whiting (Micromesistius poutassou and Northeast Atlantic (NEA mackerel (Scomber scombrus are extremely abundant pelagic planktivores that feed in the Norwegian Sea (NS during spring and summer. This study investigated the feeding ecology and diet composition of these commercially important fish stocks on the basis of biological data, including an extensive set of stomach samples in combination with hydrographical data, zooplankton samples and acoustic abundance data from 12 stock monitoring surveys carried out in 2005-2010. Mackerel were absent during the spring, but had generally high feeding overlap with herring in the summer, with a diet mainly based on calanoid copepods, especially Calanus finmarchicus, as well as a similar diet width. Stomach fullness in herring diminished from spring to summer and feeding incidence was lower than that of mackerel in summer. However, stomach fullness did not differ between the two species, indicating that herring maintain an equally efficient pattern of feeding as mackerel in summer, but on a diet that is less dominated by copepods and is more reliant on larger prey. Blue whiting tended to have a low dietary overlap with mackerel and herring, with larger prey such as euphausiids and amphipods dominating, and stomach fullness and feeding incidence increasing with length. For all the species, feeding incidence increased with decreasing temperature, and for mackerel so did stomach fullness, indicating that feeding activity is highest in areas associated with colder water masses. Significant annual effects on diet composition and feeding-related variables suggested that the three species are able to adapt to different food and environmental conditions. These annual effects are likely to have an important impact on the predation pressure on different plankton groups and the carrying capacity of individual systems, and emphasise the importance of

  14. Feeding Ecology of Northeast Atlantic Mackerel, Norwegian Spring-Spawning Herring and Blue Whiting in the Norwegian Sea.

    Science.gov (United States)

    Bachiller, Eneko; Skaret, Georg; Nøttestad, Leif; Slotte, Aril

    2016-01-01

    The Norwegian spring-spawning (NSS) herring (Clupea harengus), blue whiting (Micromesistius poutassou) and Northeast Atlantic (NEA) mackerel (Scomber scombrus) are extremely abundant pelagic planktivores that feed in the Norwegian Sea (NS) during spring and summer. This study investigated the feeding ecology and diet composition of these commercially important fish stocks on the basis of biological data, including an extensive set of stomach samples in combination with hydrographical data, zooplankton samples and acoustic abundance data from 12 stock monitoring surveys carried out in 2005-2010. Mackerel were absent during the spring, but had generally high feeding overlap with herring in the summer, with a diet mainly based on calanoid copepods, especially Calanus finmarchicus, as well as a similar diet width. Stomach fullness in herring diminished from spring to summer and feeding incidence was lower than that of mackerel in summer. However, stomach fullness did not differ between the two species, indicating that herring maintain an equally efficient pattern of feeding as mackerel in summer, but on a diet that is less dominated by copepods and is more reliant on larger prey. Blue whiting tended to have a low dietary overlap with mackerel and herring, with larger prey such as euphausiids and amphipods dominating, and stomach fullness and feeding incidence increasing with length. For all the species, feeding incidence increased with decreasing temperature, and for mackerel so did stomach fullness, indicating that feeding activity is highest in areas associated with colder water masses. Significant annual effects on diet composition and feeding-related variables suggested that the three species are able to adapt to different food and environmental conditions. These annual effects are likely to have an important impact on the predation pressure on different plankton groups and the carrying capacity of individual systems, and emphasise the importance of regular

  15. Dynamics of individual growth in a recovering population of lake trout (Salvelinus namaycush)

    Science.gov (United States)

    Fabrizio, Mary C.; Dorazio, Robert M.; Schram, Stephen T.

    2001-01-01

    In 1976, the Wisconsin Department of Natural Resources established a refuge for a nearly depleted population of lake trout (Salvelinus namaycush) at Gull Island Shoal, Lake Superior. The refuge was intended to reduce fishing mortality by protecting adult lake trout. We examined the growth dynamics of these lake trout during the period of recovery by comparing estimates of ndividual growth before and after the refuge was established. Our estimates are based on an annual mark-recapture survey conducted at the spawning area since 1969. We developed a model that allowed mean growth rates to differ among individuals of different sizes and that accommodated variation in growth rates of individuals of the same size. Likelihood ratio tests were used to determine if the mean growth increments of lake trout changed ater the refuge was established. Our results suggest that growth of mature lake trout (particularly wild fish) decreased significantly in the postrefuge period. This decreased growth may have been associated with a reduction in food availability. We also observed reductions in growth as wild fish grew older and larger, which suggests that the growth of these fish may be adequately approximated by a von Bertalanffy growth model if it becomes possible to obtain accurate ages.

  16. Principles of lake sedimentology

    International Nuclear Information System (INIS)

    Janasson, L.

    1983-01-01

    This book presents a comprehensive outline on the basic sedimentological principles for lakes, and focuses on environmental aspects and matters related to lake management and control-on lake ecology rather than lake geology. This is a guide for those who plan, perform and evaluate lake sedimentological investigations. Contents abridged: Lake types and sediment types. Sedimentation in lakes and water dynamics. Lake bottom dynamics. Sediment dynamics and sediment age. Sediments in aquatic pollution control programmes. Subject index

  17. Variation in immune parameters and disease prevalence among Lesser Black-backed Gulls (Larus fuscus sp. with different migratory strategies.

    Directory of Open Access Journals (Sweden)

    Elena Arriero

    Full Text Available The ability to control infections is a key trait for migrants that must be balanced against other costly features of the migratory life. In this study we explored the links between migration and disease ecology by examining natural variation in parasite exposure and immunity in several populations of Lesser Black-backed Gulls (Larus fuscus with different migratory strategies. We found higher activity of natural antibodies in long distance migrants from the nominate subspecies L.f.fuscus. Circulating levels of IgY showed large variation at the population level, while immune parameters associated with antimicrobial activity showed extensive variation at the individual level irrespective of population or migratory strategy. Pathogen prevalence showed large geographical variation. However, the seroprevalence of one of the gull-specific subtypes of avian influenza (H16 was associated to the migratory strategy, with lower prevalence among the long-distance migrants, suggesting that migration may play a role in disease dynamics of certain pathogens at the population level.

  18. Immunoreactive cortisone in droppings reflect stress levels, diet and growth rate of gull-billed tern chicks.

    Science.gov (United States)

    Albano, Noelia; Santiago-Quesada, Francisco; Masero, José A; Sánchez-Guzmán, Juan M; Möstl, Erich

    2015-03-01

    Blood levels of corticosterone have been traditionally analyzed to assess stress levels in birds; however, measuring steroid hormone metabolites in feces and droppings has gained much interest as a noninvasive technique successfully used for such purposed in vertebrates. Diet may affect these fecal metabolite levels (e.g., due to nutritional stress), however, this variable has not been taken into account in studies with chicks despite the great dietary flexibility of many avian species. In this study, we addressed for the first time this key issue and validated the technique in wild gull-billed tern chicks (Gelochelidon nilotica). Several enzyme immunoassays were used to determine the most appropriate test to measure the stress response. Subsequently, we performed an experiment in captivity to assess adrenocortical activity in gull-billed tern chicks fed with two diets: piscivorous vs. insectivorous. Finally, the relation between the chicks' growth rate and excreted immunoreactive glucocorticoid metabolites (EGMs) was also evaluated. We found the immunoreactive cortisone metabolites to be a good index of stress (as being an index of adrenocortical reactivity) in chicks of this species. Fish-fed chicks had higher levels of cortisone metabolites when comparing both concentration and total daily excreted metabolites. Within each treatment diet, cortisone metabolite levels and growth rates were negatively correlated. These findings suggest that the diet should be considered when using this technique for comparative purposes and highlight the trade-off between stress levels and chicks growth rates. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Use of a nesting platform by Gull-billed Terns and Black Skimmers at the Salton Sea, California

    Science.gov (United States)

    Molina, Kathy C.; Ricca, Mark A.; Miles, A. Keith; Schoneman, Christian

    2009-01-01

    In 2006, we constructed an elevated nesting platform at the Salton Sea, California, and monitored its use by Gull-billed Terns and Black Skimmers over three subsequent breeding seasons. Black Skimmers were the first to colonize the platform with a total of five nests in 2006. In 2007 Gull-billed Terns colonized the platform with a total of 28 nests and the number of Black Skimmer nests increased to 20. Neither species nested on the platform in 2008. Low success for both species was probably influenced by at least two factors. First, when both species nested on the platform, nest densities were higher than is typical of their colonies on larger, earthen islands, and colony success may have been reduced by overcrowding. Second, lack of access to water may have reduced chicks' ability to thermoregulate effectively in the hot environment of the Salton Sea. Refinements to the size, design, and location of artificial nesting habitats are necessary to enhance productivity of colonial groundnesting birds at the Salton Sea successfully.

  20. Spatial and temporal variation in winter condition of juvenile Pacific herring (Clupea pallasii) in Prince William Sound, Alaska: Oceanographic exchange with the Gulf of Alaska

    Science.gov (United States)

    Gorman, Kristen B.; Kline, Thomas C.; Roberts, Megan E.; Sewall, Fletcher F.; Heintz, Ron A.; Pegau, W. Scott

    2018-01-01

    Spatial variability in early and late winter measures of whole body energy density of juvenile (age-0) Pacific herring (Clupea pallasii) of Prince William Sound (PWS), Alaska was examined over nine years of study. Pacific herring in this region remain considered as an injured resource over the 25 years following the Exxon Valdez oil spill, however factors responsible for the lack of recovery by herring in PWS are a source of ongoing debate. Given the species' key ecological role in energy transfer to higher predators, and its economic role in a historical commercial fishery within the region, significant research effort has focused on understanding environmental factors that shape nutritional processes and the quality of these young forage fish. During November (early winter), factors such as juvenile herring body size, hydrological region of PWS, year, and the interaction between carbon (δ13C‧) or nitrogen (δ15N) stable isotope signature and hydrological region were all important predictors of juvenile herring energy density. In particular, analyses indicated that in the northern and western regions of PWS, juvenile herring with more depleted δ13C‧ values (which reflect a Gulf of Alaska carbon source) were more energy dense. Results suggest that intrusion of water derived from the Gulf of Alaska enhances the condition of age-0 herring possibly through alterations in zooplankton community structure and abundance, particularly in the northern and western regions of PWS in the fall, which is consistent with regional circulation. During March (late winter), factors such as juvenile herring body size, year, and the interaction between δ13C‧ or δ15N isotope signature and year were all important predictors of juvenile herring energy density. Results differed for early and late winter regarding the interaction between stable isotope signatures and region or year, suggesting important seasonal aspects of circulation contribute to variation in PWS juvenile

  1. Purification and characterization of cathepsin D from herring muscle ( Clupea harengus )

    DEFF Research Database (Denmark)

    Nielsen, L.B.; Nielsen, Henrik Hauch

    2001-01-01

    hamatus) and trout ovary (Oncorhynchus mykiss). Digestion of the P-chain of oxidized insulin resulted in preferential cleavage at Leu(15)-Tyr(16), (47%), Tyr(16)-Leu(17) (34%) and Ala(14)- Leu(15) (18%). Incubation with myofibrils from herring muscle at pH 4.23 showed that the enzyme mainly degraded......Cathepsin D was purified and concentrated 469-fold from a homogenate of Clupea harengus muscle. The purified enzyme is a monomer with a molecular weight of 38 000-39 000. It is inhibited by pepstatin and has optimal activity at pH 2.5 with hemoglobin as the substrate. The isoelectric point is at p...

  2. Forecasting fish stock dynamics under climate change: Baltic herring (Clupea harengus) as a case study

    DEFF Research Database (Denmark)

    Bartolino, V.; Margonski, P.; Lindegren, Martin

    2014-01-01

    Climate change and anthropogenic disturbances may affect marine populations and ecosystems through multiple pathways. In this study we present a framework in which we integrate existing models and knowledge on basic regulatory processes to investigate the potential impact of future scenarios...... of fisheries exploitation and climate change on the temporal dynamics of the central Baltic herring stock. Alternative scenarios of increasing sea surface temperature and decreasing salinity of the Baltic Sea from a global climate model were combined with two alternative fishing scenarios, and their direct......-term fish dynamics can be an informative tool to derive expectations of the potential long-term impact of alternative future scenarios of exploitation and climate change...

  3. The North Sea autumn spawning herring (Clupea harengus L.) Spawning Component Abundance Index (SCAI)

    DEFF Research Database (Denmark)

    2013-01-01

    , the sum of the fitted abundance indices across all components proves an excellent proxy for the biomass of the total stock, even though the model utilizes information at the individual-component level. The Orkney-Shetland component appears to have recovered faster from historic depletion events than......The North Sea autumn-spawning herring (Clupea harengus) stock consists of a set of different spawning components. The dynamics of the entire stock have been well characterized, but although time-series of larval abundance indices are available for the individual components, study of the dynamics...... at the component level has historically been hampered by missing observations and high sampling noise. A simple state-space statistical model is developed that is robust to these problems, gives a good fit to the data, and proves capable of both handling and predicting missing observations well. Furthermore...

  4. The effect of progressive hypoxia on school structure and dynamics in Atlantic herring Clupea harengus

    DEFF Research Database (Denmark)

    Domenici, Paolo; Ferrari, R Silvana; Steffensen, John F

    2002-01-01

    The effect of progressive hypoxia on the structure and dynamics of herring (Clupea harengus) schools in laboratory conditions was investigated. The length, width and depth of schools of about 20 individuals were measured from video recordings to test the hypothesis that during hypoxia fish schools...... change their shape and volume. School shape (calculated as the ratios of length/depth, width/depth and length/width) did not change significantly during hypoxia. School length, width, depth, area and volume were all significantly increased at 20% oxygen saturation. Volume, area and width were more...... to overtaking or falling back by individual fishes. School integrity and positional dynamics are the outcome of trade-offs among a number of biotic factors, such as food, predator defence, mating behaviour and various physical factors that may impose certain limits. Among these, our results indicate that oxygen...

  5. Real-time ichthyoplankton drift in Northeast Arctic cod and Norwegian spring-spawning herring.

    Science.gov (United States)

    Vikebø, Frode B; Ådlandsvik, Bjørn; Albretsen, Jon; Sundby, Svein; Stenevik, Erling Kåre; Huse, Geir; Svendsen, Einar; Kristiansen, Trond; Eriksen, Elena

    2011-01-01

    Individual-based biophysical larval models, initialized and parameterized by observations, enable numerical investigations of various factors regulating survival of young fish until they recruit into the adult population. Exponentially decreasing numbers in Northeast Arctic cod and Norwegian Spring Spawning herring early changes emphasizes the importance of early life history, when ichthyoplankton exhibit pelagic free drift. However, while most studies are concerned with past recruitment variability it is also important to establish real-time predictions of ichthyoplankton distributions due to the increasing human activity in fish habitats and the need for distribution predictions that could potentially improve field coverage of ichthyoplankton. A system has been developed for operational simulation of ichthyoplankton distributions. We have coupled a two-day ocean forecasts from the Norwegian Meteorological Institute with an individual-based ichthyoplankton model for Northeast Arctic cod and Norwegian Spring Spawning herring producing daily updated maps of ichthyoplankton distributions. Recent years observed spawning distribution and intensity have been used as input to the model system. The system has been running in an operational mode since 2008. Surveys are expensive and distributions of early stages are therefore only covered once or twice a year. Comparison between model and observations are therefore limited in time. However, the observed and simulated distributions of juvenile fish tend to agree well during early fall. Area-overlap between modeled and observed juveniles September 1(st) range from 61 to 73%, and 61 to 71% when weighted by concentrations. The model system may be used to evaluate the design of ongoing surveys, to quantify the overlap with harmful substances in the ocean after accidental spills, as well as management planning of particular risky operations at sea. The modeled distributions are already utilized during research surveys to

  6. Real-time ichthyoplankton drift in Northeast Arctic cod and Norwegian spring-spawning herring.

    Directory of Open Access Journals (Sweden)

    Frode B Vikebø

    Full Text Available BACKGROUND: Individual-based biophysical larval models, initialized and parameterized by observations, enable numerical investigations of various factors regulating survival of young fish until they recruit into the adult population. Exponentially decreasing numbers in Northeast Arctic cod and Norwegian Spring Spawning herring early changes emphasizes the importance of early life history, when ichthyoplankton exhibit pelagic free drift. However, while most studies are concerned with past recruitment variability it is also important to establish real-time predictions of ichthyoplankton distributions due to the increasing human activity in fish habitats and the need for distribution predictions that could potentially improve field coverage of ichthyoplankton. METHODOLOGY/PRINCIPAL FINDINGS: A system has been developed for operational simulation of ichthyoplankton distributions. We have coupled a two-day ocean forecasts from the Norwegian Meteorological Institute with an individual-based ichthyoplankton model for Northeast Arctic cod and Norwegian Spring Spawning herring producing daily updated maps of ichthyoplankton distributions. Recent years observed spawning distribution and intensity have been used as input to the model system. The system has been running in an operational mode since 2008. Surveys are expensive and distributions of early stages are therefore only covered once or twice a year. Comparison between model and observations are therefore limited in time. However, the observed and simulated distributions of juvenile fish tend to agree well during early fall. Area-overlap between modeled and observed juveniles September 1(st range from 61 to 73%, and 61 to 71% when weighted by concentrations. CONCLUSIONS/SIGNIFICANCE: The model system may be used to evaluate the design of ongoing surveys, to quantify the overlap with harmful substances in the ocean after accidental spills, as well as management planning of particular risky operations

  7. Anatomy and histochemistry of spread-wing posture in birds. 2. Gliding flight in the California gull, Larus californicus: a paradox of fast fibers and posture.

    Science.gov (United States)

    Meyers, R A; Mathias, E

    1997-09-01

    Gliding flight is a postural activity which requires the wings to be held in a horizontal position to support the weight of the body. Postural behaviors typically utilize isometric contractions in which no change in length takes place. Due to longer actin-myosin interactions, slow contracting muscle fibers represent an economical means for this type of contraction. In specialized soaring birds, such as vultures and pelicans, a deep layer of the pectoralis muscle, composed entirely of slow fibers, is believed to perform this function. Muscles involved in gliding posture were examined in California gulls (Larus californicus) and tested for the presence of slow fibers using myosin ATPase histochemistry and antibodies. Surprisingly small numbers of slow fibers were found in the M. extensor metacarpi radialis, M. coracobrachialis cranialis, and M. coracobrachialis caudalis, which function in wrist extension, wing protraction, and body support, respectively. The low number of slow fibers in these muscles and the absence of slow fibers in muscles associated with wing extension and primary body support suggest that gulls do not require slow fibers for their postural behaviors. Gulls also lack the deep belly to the pectoralis found in other gliding birds. Since bird muscle is highly oxidative, we hypothesize that fast muscle fibers may function to maintain wing position during gliding flight in California gulls.

  8. REDD herring

    DEFF Research Database (Denmark)

    Kamelarczyk, Kewin Bach Friis; Smith-Hall, Carsten

    2014-01-01

    To enhance understanding of environmental science–policy interactions, this study analyses how environmental knowledge is produced, circulated, and applied in the Reduced Emissions from Deforestation and Degradation (REDD +) programme in Zambia. Data are drawn from interviews with key actors...... in the REDD + process and an extensive critical review of policy documents and deforestation estimates. We find that research over the past 50 years has not resulted in accurate estimates of forest cover and deforestation rates, nor have major deforestation drivers been convincingly documented. Estimates...... are difficult to compare due to inconsistent use of key terms, methodological pluralism and differences in social framing. We argue that an epistemic community is able to influence production, circulation, and application of deforestation related knowledge. Furthermore, in a situation of weak and contradictory...

  9. Great Lakes

    Science.gov (United States)

    Edsall, Thomas A.; Mac, Michael J.; Opler, Paul A.; Puckett Haecker, Catherine E.; Doran, Peter D.

    1998-01-01

    The Great Lakes region, as defined here, includes the Great Lakes and their drainage basins in Minnesota, Wisconsin, Illinois, Indiana, Ohio, Pennsylvania, and New York. The region also includes the portions of Minnesota, Wisconsin, and the 21 northernmost counties of Illinois that lie in the Mississippi River drainage basin, outside the floodplain of the river. The region spans about 9º of latitude and 20º of longitude and lies roughly halfway between the equator and the North Pole in a lowland corridor that extends from the Gulf of Mexico to the Arctic Ocean.The Great Lakes are the most prominent natural feature of the region (Fig. 1). They have a combined surface area of about 245,000 square kilometers and are among the largest, deepest lakes in the world. They are the largest single aggregation of fresh water on the planet (excluding the polar ice caps) and are the only glacial feature on Earth visible from the surface of the moon (The Nature Conservancy 1994a).The Great Lakes moderate the region’s climate, which presently ranges from subarctic in the north to humid continental warm in the south (Fig. 2), reflecting the movement of major weather masses from the north and south (U.S. Department of the Interior 1970; Eichenlaub 1979). The lakes act as heat sinks in summer and heat sources in winter and are major reservoirs that help humidify much of the region. They also create local precipitation belts in areas where air masses are pushed across the lakes by prevailing winds, pick up moisture from the lake surface, and then drop that moisture over land on the other side of the lake. The mean annual frost-free period—a general measure of the growing-season length for plants and some cold-blooded animals—varies from 60 days at higher elevations in the north to 160 days in lakeshore areas in the south. The climate influences the general distribution of wild plants and animals in the region and also influences the activities and distribution of the human

  10. THE GOAL AND THE GOLD MINE: Constraints Management and the Dutch Herring Fishing Industry, 1400-1700

    Directory of Open Access Journals (Sweden)

    Michael Scott Martin

    2009-01-01

    Full Text Available In many ways, the Netherlands set the pace for European economic growth in the fifteenth through the eighteenth centuries. The Dutch herring fishing industry was critical to this modern economic progress. A comparative study of this enterprise to the lean manufacturing tool of constraints management provides insight into how the Dutch dominated this lucrative industry. Improvements by Dutch fishing interests in technology, practice, procedures and quality control were consistent with the constraints management model. English and Scottish competitors failed to identify these constraints and thus, failed to challenge Dutch operators. The Dutch fishing industry practiced and understood constraints management and used it to monopolize the export herring market for three centuries.

  11. Principles underlying the epizootiology of viral hemorrhagic septicemia in Pacific herring and other fishes throughout the North Pacific Ocean

    Science.gov (United States)

    Hershberger, Paul K.; Garver, Kyle A.; Winton, James R.

    2016-01-01

    Although viral hemorrhagic septicemia virus (VHSV) typically occurs at low prevalence and intensity in natural populations of Pacific herring (Clupea pallasii) and other marine fishes in the Northeast Pacific Ocean, epizootics of the resulting disease (VHS) periodically occur, often in association with observed fish kills. Here we identify a list of principles, based on a combination of field studies, controlled laboratory experiments, and previously unpublished observations, that govern the epizootiology of VHS in Pacific herring. A thorough understanding of these principles provides the basis for identifying risk factors that predispose certain marine fish populations to VHS epizootics, including the lack of population resistance, presence of chronic viral carriers in a population, copious viral shedding by infected individuals, cool water temperatures, limited water circulation patterns, and gregarious host behavioral patterns. Further, these principles are used to define the epizootiological stages of the disease in Pacific herring, including the susceptible (where susceptible individuals predominate a school or subpopulation), enzootic (where infection prevalence and intensity are often below the limits of reasonable laboratory detection), disease amplification (where infection prevalence and intensity increase rapidly), outbreak (often accompanied by host mortalities with high virus loads and active shedding), recovery (in which the mortality rate and virus load decline owing to an active host immune response), and refractory stages (characterized by little or no susceptibility and where viral clearance occurs in most VHS survivors). In addition to providing a foundation for quantitatively assessing the potential risks of future VHS epizootics in Pacific herring, these principles provide insights into the epizootiology of VHS in other fish communities where susceptible species exist.

  12. In situ exposure of herring embryos in Prince William Sound two years after the Exxon Valdez oil spill

    International Nuclear Information System (INIS)

    Kocan, R.; Brown, E.; Baker, T.

    1995-01-01

    In order to evaluate long-term residual toxicity, artificially spawned Pacific herring (Clupea pallasl) embryos were deployed at 5 oiled and 5 unoiled sites in Prince William Sound two years after the Exxon Valdez oil spill. Embryos were exposed at 1.5 m and 4.5 m below mean low water for 8--10 d post fertilization. The embryos were then retrieved and transported to the laboratory for hatching and evaluation under controlled conditions, Endpoints were (1) embryo survival, (2) live hatch, (3) deformed larvae and (4) larval dry weight. The oiled sites produced significantly (P < 0.01) more deformed larvae (63.3%) than did the unoiled sites (51.3%), but there was a lower hatching success at the unoiled sites which resulted in no overall difference in normal live larvae produced between oiled and unoiled sites. The mean dry weight of newly hatched larvae from the oiled sites (78 microg/larva) was significantly lower than those from the unoiled sites (97 microg/larva) at all depths (P < 0.01). Increased larval deformities and reduced hatching weight is consistent with what has been reported by several investigators for herring larvae experimentally and naturally exposed to petroleum hydrocarbons. Based on the data, there appeared to be differences between the previously oiled and unoiled sites relative to herring development, but it is not clear whether this was due to residual oil effects or parental effects

  13. Round herring (genus Etrumeus) contain distinct evolutionary lineages coincident with a biogeographic barrier along Australia’s southern temperate coastline

    KAUST Repository

    DiBattista, Joseph; Randall, John E.; Newman, Stephen J.; Bowen, Brian W.

    2014-01-01

    Molecular genetic surveys of marine fishes have revealed that some widely distributed species are actually a composite of multiple evolutionary lineages. This is apparent in the round herrings (genus Etrumeus), wherein a globally distributed taxon (Etrumeus sadina Mitchill 1814) has proven to contain at least seven valid taxa, with more likely awaiting discovery. Here, we survey evolutionary lineages of the nominal E. sadina (formerly E. teres, a junior synonym) across the southern temperate zone of Australia, a marine region divided into three biogeographic provinces based primarily on the distribution of intertidal faunas. Results from morphological and mitochondrial DNA data reveal two evolutionary lineages corresponding to eastern and southwestern provinces (d = 0.007 for cytochrome c oxidase subunit I and d = 0.017 for cytochrome b), possibly initiated by the Bassian Isthmus between Australia and Tasmania during low sea-level stands. The Australian round herring is also genetically distinct from the nearest congeneric forms in the Indian and Pacific Oceans, with a corresponding modal difference in gill-raker counts in most cases. Based on these data, we resurrect the title Etrumeus jacksoniensis for the Australian round herring. While the Bassian Isthmus may have initiated the partition of evolutionary lineages within Australia, additional oceanographic and ecological factors must reinforce this separation in order to maintain diagnostic genetic differences along a continuous temperate coastline. © 2014 Springer-Verlag Berlin Heidelberg.

  14. Round herring (genus Etrumeus) contain distinct evolutionary lineages coincident with a biogeographic barrier along Australia’s southern temperate coastline

    KAUST Repository

    DiBattista, Joseph

    2014-08-28

    Molecular genetic surveys of marine fishes have revealed that some widely distributed species are actually a composite of multiple evolutionary lineages. This is apparent in the round herrings (genus Etrumeus), wherein a globally distributed taxon (Etrumeus sadina Mitchill 1814) has proven to contain at least seven valid taxa, with more likely awaiting discovery. Here, we survey evolutionary lineages of the nominal E. sadina (formerly E. teres, a junior synonym) across the southern temperate zone of Australia, a marine region divided into three biogeographic provinces based primarily on the distribution of intertidal faunas. Results from morphological and mitochondrial DNA data reveal two evolutionary lineages corresponding to eastern and southwestern provinces (d = 0.007 for cytochrome c oxidase subunit I and d = 0.017 for cytochrome b), possibly initiated by the Bassian Isthmus between Australia and Tasmania during low sea-level stands. The Australian round herring is also genetically distinct from the nearest congeneric forms in the Indian and Pacific Oceans, with a corresponding modal difference in gill-raker counts in most cases. Based on these data, we resurrect the title Etrumeus jacksoniensis for the Australian round herring. While the Bassian Isthmus may have initiated the partition of evolutionary lineages within Australia, additional oceanographic and ecological factors must reinforce this separation in order to maintain diagnostic genetic differences along a continuous temperate coastline. © 2014 Springer-Verlag Berlin Heidelberg.

  15. Muscle Thiobarbituric Acid Reactive Substance of the Atlantic Herring (Clupea harengus in Marinades Collected in the Market Network

    Directory of Open Access Journals (Sweden)

    Alena Halamíčková

    2010-01-01

    Full Text Available Fish fat belongs to highly specific nutritious elements especially due to its high content of polyunsaturated fatty acids. The aim of the present study was to determine the content of 2-thiobarbituric acid reactive substances in over-the-counter cold and warm marinades in which the base fish material consists of the Atlantic herring (Clupea harengus. Fifty six marinated fish products stored at refrigeration temperatures were analyzed before their expiration date. Their fat content was determined by means of the Soxhlet method and the TBARS validated fluorimetric micromethod. Lowest TBARS values were characteristic of warm baked marinades (1.17 ± 0.40 mg MDA/ kg muscle and in case of cold marinades for the rolled herring fillets with pepper (5.03 ± 0.54 mg MDA/kg muscle whereas the highest TBARS values were observed in warm cooked marinades (16.48 ± 4.22 mg MDA/kg muscle and in roll mops sold over the counter (7.61 ± 3.87 mg MDA/kg muscle. The results showed that fat content is not always critical for herring TBARS determination in marinades. For the consumer safety it is essential to pay attention to cold marinades in brine sold over the counter and baked marinades in aspic before their expiration date.

  16. Characteristics of the Norwegian Coastal Current during Years with High Recruitment of Norwegian Spring Spawning Herring (Clupea harengus L..

    Directory of Open Access Journals (Sweden)

    Øystein Skagseth

    Full Text Available Norwegian Spring Spawning herring (NSSH Clupea harengus L. spawn on coastal banks along the west coast of Norway. The larvae are generally transported northward in the Norwegian Coastal Current (NCC with many individuals utilizing nursery grounds in the Barents Sea. The recruitment to this stock is highly variable with a few years having exceptionally good recruitment. The principal causes of recruitment variability of this herring population have been elusive. Here we undertake an event analysis using data between 1948 and 2010 to gain insight into the physical conditions in the NCC that coincide with years of high recruitment. In contrast to a typical year when northerly upwelling winds are prominent during spring, the years with high recruitment coincide with predominantly southwesterly winds and weak upwelling in spring and summer, which lead to an enhanced northward coastal current during the larval drift period. Also in most peak recruitment years, low-salinity anomalies are observed to propagate northward during the spring and summer. It is suggested that consistent southwesterly (downwelling winds and propagating low-salinity anomalies, both leading to an enhanced northward transport of larvae, are important factors for elevated recruitment. At the same time, these conditions stabilize the coastal waters, possibly leading to enhanced production and improved feeding potential along the drift route to Barents Sea. Further studies on the drivers of early life history mortality can now be undertaken with a better understanding of the physical conditions that prevail during years when elevated recruitment occurs in this herring stock.

  17. Audouin's gull chicks as bioindicators of mercury pollution at different breeding locations in the western Mediterranean

    Energy Technology Data Exchange (ETDEWEB)

    Sanpera, Carolina [Departament Biologia Animal, Facultat de Biologia, Universitat de Barcelona, Diagonal 645, 08028 Barcelona (Spain)]. E-mail: csanpera@ub.edu; Moreno, Roci' o [Departament Biologia Animal, Facultat de Biologia, Universitat de Barcelona, Diagonal 645, 08028 Barcelona (Spain); Ruiz, Xavier [Departament Biologia Animal, Facultat de Biologia, Universitat de Barcelona, Diagonal 645, 08028 Barcelona (Spain); Jover, Lluis [Departament Salut Publica, Facultat de Medicina, Universitat de Barcelona, Casanova 143, 08036 Barcelona (Spain)

    2007-06-15

    Mercury levels of Audouin's gull are amongst the highest for Mediterranean seabirds, and have been mainly attributed to its piscivorous habits in these naturally Hg rich waters. Moreover, two additional factors could enhance its mercury intake: the consumption of discarded fish (which attain higher concentrations) and/or feeding in areas receiving Hg anthropogenic inputs. In order to differentiate the relevance of both sources we analysed Hg and stable isotopes of chick feathers from different breeding locations in western Mediterranean: one in its northern part (Ebro Delta) and two southern (Chafarinas Isl. and Alboran Isl.). The results from stable isotopes indicate that consumption of discards is higher at Alboran Isl., followed by the Ebro Delta and Chafarinas Isl. Thus, the higher mercury levels found in the Ebro Delta cannot be explained uniquely by the contribution of discarded fish to diet, but local pollution caused by the river Ebro waters accounts for Hg differences observed.

  18. Wild Birds as biological indicators of environmental pollution: biotyping and antimicrobial resistance patterns of Escherichia coli isolated from Audouin's gulls (Larus Audouinii living in the Bay of Gallipoli (Italy

    Directory of Open Access Journals (Sweden)

    Egidio Mallia

    2010-01-01

    Full Text Available E. Coli biotyping and antimicrobial succeptibility tests were performed on fortyeight cloacal swabs collected from a popoulation of Audouin's gulls ((Larus Audouinii living in the Bay of Gallipoli (Lecce, Italy. The aim was to assess the pathogenic potential of the strains the gulls carry and shed into the environment and to gain a better understanding of the microbial pollution of the aera they live in.

  19. Wild Birds as biological indicators of environmental pollution: biotyping and antimicrobial resistance patterns of Escherichia coli isolated from Audouin's gulls (Larus Audouinii living in the Bay of Gallipoli (Italy

    Directory of Open Access Journals (Sweden)

    Antonio Camarda

    2006-01-01

    Full Text Available E. Coli biotyping and antimicrobial succeptibility tests were performed on fortyeight cloacal swabs collected from a popoulation of Audouin's gulls ((Larus Audouinii living in the Bay of Gallipoli (Lecce, Italy. The aim was to assess the pathogenic potential of the strains the gulls carry and shed into the environment and to gain a better understanding of the microbial pollution of the aera they live in.

  20. Morphometric variation among spawning cisco aggregations in the Laurentian Great Lakes: are historic forms still present?

    Science.gov (United States)

    Yule, Daniel L.; Moore, Seth A.; Ebener, Mark P.; Claramunt, Randall M.; Pratt, Thomas C.; Salawater, Lorrie L.; Connerton, Michael J.

    2013-01-01

    Cisco (Coregonus artedi Leseur, formerly lake herring Leucichthys artedi Leseur) populations in each of the Laurentian Great Lakes collapsed between the late 1920s and early 1960s following a multitude of stressors, and never recovered in Lakes Michigan, Erie and Ontario. Prior to their collapse, Koelz (1929) studied Leucichthys spp. in the Great Lakes basin and provided a description of their diversity. Three cisco morphotypes were described; a ‘slim terete’morphotype (L. artedi artedi), a ‘deep compressed’ morphotype (L. artedi albus), and a deep-bodied form resembling tullibee in western Canadian lakes (L. artedi manitoulinus). Based on body measurements of 159 individuals (Koelz 1929), we used discriminant function analysis (DFA) to discriminate historic morphotypes. Shapes of historic morphotypes were found to vary significantly (Pillai’s trace = 1.16, P cisco. Important discriminating measurements included body depth, eye diameter, and dorsal fin base and height. Between October-November of 2007-2011, we sampled cisco from 16 Great Lakes sites collecting digital photographs of over 1, 700 individuals. We applied the DFA model to their body measurements and classified each individual to a morphotype. Contemporary cisco from Lakes Superior, Ontario and Michigan were predominantly classified as artedi, while the most common classifications from northern Lake Huron were albus and manitoulinus. Finding historic morphotypes is encouraging because it suggests that the morphological variation present prior to their collapse still exists. We conclude that contemporary cisco having shapes matching the missing historic morphotypes in the lower lakes warrant special consideration as potential donor populations in reestablishment efforts.

  1. Bathymetry of Lake Michigan

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Michigan has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  2. Bathymetry of Lake Ontario

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Ontario has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  3. Bathymetry of Lake Superior

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Superior has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  4. Great Lakes Bathymetry

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lakes Michigan, Erie, Saint Clair, Ontario and Huron has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and...

  5. Bathymetry of Lake Huron

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Huron has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  6. Great Lakes Science Center

    Data.gov (United States)

    Federal Laboratory Consortium — Since 1927, Great Lakes Science Center (GLSC) research has provided critical information for the sound management of Great Lakes fish populations and other important...

  7. Viral replication in excised fin tissues (VREFT) corresponds with prior exposure of Pacific herring, Clupea pallasii (Valenciennes), to viral haemorrhagic septicaemia virus (VHSV)

    Science.gov (United States)

    Grady, C.A.; Gregg, J.L.; Wade, R.M.; Winton, J.R.; Hershberger, P.K.

    2011-01-01

    Procedures for a viral replication in excised fin tissue (VREFT) assay were adapted to Pacific herring, Clupea pallasii, and optimized both to reduce processing time and to provide the greatest resolution between na??ve herring and those previously exposed to viral haemorrhagic septicaemia virus (VHSV), Genogroup IVa. The optimized procedures included removal of the left pectoral fin from a euthanized fish, inoculation of the fin with >105 plaque-forming units (PFU) mL-1 VHSV for 1 h, rinsing the fin in fresh medium six times to remove unadsorbed virions, incubation of the fin in fresh medium for 4 days and enumeration of the viral titre in a sample of the incubation medium by plaque assay. The optimized VREFT assay was effective at identifying the prior exposure history of laboratory-reared Pacific herring to VHSV. The geometric mean VREFT value was significantly greater (P < 0.01) among na??ve herring (1.2 ?? 103 PFU mL-1) than among groups that survived exposure to VHSV (1.0-2.9 ?? 102 PFU mL-1); additionally, the proportion of cultures with no detectable virus was significantly greater (P = 0.0002) among fish that survived exposure to VHSV (39-47%) than among na??ve fish (3.3%). The optimized VREFT assay demonstrates promise for identifying VHSV exposure history and forecasting disease potential in populations of wild Pacific herring. ?? 2010 Blackwell Publishing Ltd.

  8. Direct Effects of Microalgae and Protists on Herring (Clupea harengus Yolk Sac Larvae.

    Directory of Open Access Journals (Sweden)

    Björn Illing

    Full Text Available This study investigated effects of microalgae (Rhodomonas baltica and heterotrophic protists (Oxyrrhis marina on the daily growth, activity, condition and feeding success of Atlantic herring (Clupea harengus larvae from hatch, through the end of the endogenous (yolk sac period. Yolk sac larvae were reared in the presence and absence of microplankton and, each day, groups of larvae were provided access to copepods. Larvae reared with microalgae and protists exhibited precocious (2 days earlier and ≥ 60% increased feeding incidence on copepods compared to larvae reared in only seawater (SW. In the absence and presence of microalgae and protists, life span and growth trajectories of yolk sac larvae were similar and digestive enzyme activity (trypsin and nutritional condition (RNA-DNA ratio markedly declined in all larvae directly after yolk sac depletion. Thus, microplankton promoted early feeding but was not sufficient to alter life span and growth during the yolk sac phase. Given the importance of early feeding, field programs should place greater emphasis on the protozooplankton-ichthyoplankton link to better understand match-mismatch dynamics and bottom-up drivers of year class success in marine fish.

  9. Minors' capacity to refuse treatment: a reply to Gilmore and Herring.

    Science.gov (United States)

    Cave, Emma; Wallbank, Julie

    2012-01-01

    Re R and Re W allow a parent to consent to treatment a competent minor refuses, but the cases have not been tested post-Human Rights Act 1998. Gilmore and Herring offer a means by which they might be distinguished or sidelined. They interpret Gillick to say that in order to consent a minor need only have a full understanding of the particular treatment. They argue that the minors in Re R and Re W were refusing all treatment which requires a separate assessment of capacity-an assessment which was not made. We fear that this distinction would not be workable in clinical practice and argue that their interpretation of Gillick is flawed. From a clinician's point of view, competence cannot always be judged in relation to a specific treatment, but instead must relate to the decision. We show that a decision can incorporate more than one treatment, and more than one decision might be made about one treatment. A minor's understanding of a specific treatment is not always sufficient to demonstrate competence to make a decision. The result is that whilst there might be situations when a parent and a minor both have the power to consent to a particular treatment, they will not share concurrent powers in relation to the same decision. Consequently, a challenge to Re R and Re W, if forthcoming, would need to take a different form. We emphasise the necessity to minimise the dichotomy between legal consent and how consent works in medical practice.

  10. Direct Effects of Microalgae and Protists on Herring (Clupea harengus) Yolk Sac Larvae.

    Science.gov (United States)

    Illing, Björn; Moyano, Marta; Niemax, Jan; Peck, Myron A

    2015-01-01

    This study investigated effects of microalgae (Rhodomonas baltica) and heterotrophic protists (Oxyrrhis marina) on the daily growth, activity, condition and feeding success of Atlantic herring (Clupea harengus) larvae from hatch, through the end of the endogenous (yolk sac) period. Yolk sac larvae were reared in the presence and absence of microplankton and, each day, groups of larvae were provided access to copepods. Larvae reared with microalgae and protists exhibited precocious (2 days earlier) and ≥ 60% increased feeding incidence on copepods compared to larvae reared in only seawater (SW). In the absence and presence of microalgae and protists, life span and growth trajectories of yolk sac larvae were similar and digestive enzyme activity (trypsin) and nutritional condition (RNA-DNA ratio) markedly declined in all larvae directly after yolk sac depletion. Thus, microplankton promoted early feeding but was not sufficient to alter life span and growth during the yolk sac phase. Given the importance of early feeding, field programs should place greater emphasis on the protozooplankton-ichthyoplankton link to better understand match-mismatch dynamics and bottom-up drivers of year class success in marine fish.

  11. SEASONAL DISTRIBUTION OF YELLOW-LEGGED GULL (LARUS CACHINNANS PALLAS, 1811 OF ISLANSDS OF OBITOCHNAYA BAY (NORTH-WEST AZOV SEA AREA

    Directory of Open Access Journals (Sweden)

    Dubinina U.U.

    2013-09-01

    Full Text Available Considered territorial connection of Yellow-legged gull in breeding colony on islands Obitochnaya Bay. Analysis of the basic stages of the annual life cycle of Larus cachinnans Pallas, 1811 with taking into account the seasonal characteristics of each age group of seagulls (young, immature, adult. Based on this data set direction and distance of displacement, among whom were identified intra-continental migrations, domestic migrations within the territory of Ukraine and migrations within the nesting area. Settlement species on islands Obitochnaya Bay characterized by: high degree conservatism of adult Yellow-legged gull a wide range in season after nesting migrations and variance of young birds, the exchange of individuals between neighbouring settlements and the establishment of new colonies at the expense of immature individuals.

  12. Lake Cadagno

    DEFF Research Database (Denmark)

    Tonolla, Mauro; Storelli, Nicola; Danza, Francesco

    2017-01-01

    cycles. The chemocline lies at about 12 m depth, stabilized by density differences of salt-rich water supplied by sub-aquatic springs to the monimolimnion and of electrolyte-poor surface water feeding the mixolimnion. Steep sulphide and light gradients in the chemocline support the growth of a large...... in the chemocline. Small-celled PSB together with the sulfate-reducing bacterium Desulfocapsa thiozymogenes sp. form stable aggregates in the lake, which represent small microenvironments with an internal sulphur cycle. Eukaryotic primary producers in the anoxic zones are dominated by Cryptomonas phaseolus...

  13. Adapting to a changing world: unraveling the role of man-made habitats as alternative feeding areas for slender-billed gull (Chroicocephalus genei.

    Directory of Open Access Journals (Sweden)

    Francisco Ramírez

    Full Text Available Current rates of wildlife habitat loss have placed increasing demands on managers to develop, validate and implement tools aimed at improving our ability to evaluate such impacts on wildlife. Here, we present a case study conducted at the Natural Area of Doñana (SW Spain where remote sensing and stable isotope (δ(13C, δ(15N analyses of individuals were combined to unravel (1 the effect of variations in availability of natural food resources (i.e. from natural marshes on reproductive performance of a Slender-billed Gull (Chroicocephalus genei population, and (2 the role of two adjacent, artificial systems (a fish farm and saltmines as alternate anthropogenic feeding areas. Based on long-term (1983-2004 remote-sensing, we inferred the average extent of flooded area at the marshland (a proxy to natural resource availability annually. Estimated flooded areas (ranging from extreme drought [ca. 151 ha, 1995] to high moisture [15,049 ha, 2004] were positively related to reproductive success of gulls (estimated for the 1993-2004 period, and ranging from ca. 0 to 1.7 fledglings per breeding pairs, suggesting that habitat availability played a role in determining their reproductive performance. Based on blood δ(13C and δ(15N values of fledglings, 2001-2004, and a Bayesian isotopic mixing model, we conclude that saltmines acted as the main alternative foraging habitat for gulls, with relative contributions increasing as the extent of marshland decreased. Although adjacent, anthropogenic systems have been established as the preferred breeding sites for this gull population, dietary switches towards exploitation of alternative (anthropogenic food resources negatively affected the reproductive output of this species, thus challenging the perception that these man-made systems are necessarily a reliable buffer against loss of natural feeding habitats. The methodology and results derived from this study could be extended to a large suite of threatened

  14. Molecular characterization and genetic diversity of ESBL-producing Escherichia coli colonizing the migratory Franklin's gulls (Leucophaeus pipixcan) in Antofagasta, North of Chile.

    Science.gov (United States)

    Báez, John; Hernández-García, Marta; Guamparito, Constanza; Díaz, Sofía; Olave, Abdon; Guerrero, Katherine; Cantón, Rafael; Baquero, Fernando; Gahona, Joselyne; Valenzuela, Nicomedes; Del Campo, Rosa; Silva, Juan

    2015-02-01

    The role of wild animals, particularly migratory birds, in the dissemination of antibiotic-resistant bacteria between geographically distant ecosystems is usually underestimated. The aim of this work was to characterize the Escherichia coli population from Franklin's gull feces, focusing on the extended-spectrum β-lactamase (ESBL)-producing strains. In the summer of 2011, 124 fecal swabs from seagulls (1 of each) migrating from the United States and Canada to the coast of Antofagasta, north of Chile, were collected. Samples were seeded on MacConkey agar supplemented with 2 μg/ml of cefotaxime and a single colony from each plate was tested for ESBL production by the double-disk ESBL synergy test. Antibiotic susceptibility was determined by the disk diffusion method and blaESBL genes were amplified and sequenced. The genetic diversity of isolates was explored by pulsed-field gel electrophoresis (PFGE)-XbaI and multilocus sequence typing. A total of 91 E. coli isolates with high rates of antibiotic resistance were identified. Carbapenemase production was not detected, whereas 67 of the 91 (54%) isolates exhibited an ESBL phenotype due to the presence of CTX-M-15 (61.3%), CTX-M-2 (19.3%), CTX-M-22 (16.1%), and CTX-M-3 (1.6%) coding genes. High genetic diversity was observed, with 30 PFGE patterns and 23 sequence types (STs), including ST131 (18%), ST44 (15%), ST617 (9%), and ST10 (9%). Results presented here are complementary to those previously reported by Hernández et al. in the same gull species, but located in the Central Region of Chile. Differences observed between gulls from both areas lead us to hypothesize that gulls from the northern location retain, as gut carriers, those resistant bacteria acquired in the United States and/or Canada.

  15. White-faced storm-petrels Pelagodroma marina predated by gulls as biological monitors of plastic pollution in the pelagic subtropical northeast atlantic

    OpenAIRE

    Furtado, Ricardo Miranda; Menezes, Dilia; Santos, Carolina Jardim; Catry, Paulo

    2016-01-01

    Marine plastic pollution is rapidly growing and is a source of major concern. Seabirds often ingest plastic debris and are increasingly used as biological monitors of plastic pollution. However, virtually no studies have assessed plastics in seabirds in the deep subtropical North Atlantic. We investigated whether remains of white-faced storm-petrels (WFSP) present in gull pellets could be used for biomonitoring. We analysed 263 pellets and 79.0% of these contained plastic debris originating i...

  16. Quantifying Streamflow Variations in Ungauged Lake Basins by Integrating Remote Sensing and Water Balance Modelling: A Case Study of the Erdos Larus relictus National Nature Reserve, China

    Directory of Open Access Journals (Sweden)

    Kang Liang

    2017-06-01

    Full Text Available Hydrological predictions in ungauged lakes are one of the most important issues in hydrological sciences. The habitat of the Relict Gull (Larus relictus in the Erdos Larus relictus National Nature Reserve (ELRNNR has been seriously endangered by lake shrinkage, yet the hydrological processes in the catchment are poorly understood due to the lack of in-situ observations. Therefore, it is necessary to assess the variation in lake streamflow and its drivers. In this study, we employed the remote sensing technique and empirical equation to quantify the time series of lake water budgets, and integrated a water balance model and climate elasticity method to further examine ELRNNR basin streamflow variations from1974 to 2013. The results show that lake variations went through three phases with significant differences: The rapidly expanding sub-period (1974–1979, the relatively stable sub-period (1980–1999, and the dramatically shrinking sub-period (2000–2013. Both climate variation (expressed by precipitation and evapotranspiration and human activities were quantified as drivers of streamflow variation, and the driving forces in the three phases had different contributions. As human activities gradually intensified, the contributions of human disturbances on streamflow variation obviously increased, accounting for 22.3% during 1980–1999 and up to 59.2% during 2000–2013. Intensified human interferences and climate warming have jointly led to the lake shrinkage since 1999. This study provides a useful reference to quantify lake streamflow and its drivers in ungauged basins.

  17. White-faced storm-petrels Pelagodroma marina predated by gulls as biological monitors of plastic pollution in the pelagic subtropical Northeast Atlantic

    International Nuclear Information System (INIS)

    Furtado, Ricardo; Menezes, Dilia; Santos, Carolina Jardim; Catry, Paulo

    2016-01-01

    Marine plastic pollution is rapidly growing and is a source of major concern. Seabirds often ingest plastic debris and are increasingly used as biological monitors of plastic pollution. However, virtually no studies have assessed plastics in seabirds in the deep subtropical North Atlantic. We investigated whether remains of white-faced storm-petrels (WFSP) present in gull pellets could be used for biomonitoring. We analysed 263 pellets and 79.0% of these contained plastic debris originating in the digestive tract of WFSP. Pellets with no bird prey did not contain plastics. Most debris were fragments (83.6%) with fewer plastic pellets (8.2%). Light-coloured plastics predominated (71.0%) and the most frequent polymer was HDPE (73.0%). Stable isotopes in toe-nails of WFSP containing many versus no plastics did not differ, indicating no individual specialisation leading to differential plastic ingestion. We suggest WFSP in pellets are highly suitable to monitor the little known pelagic subtropical Northeast Atlantic. - Highlights: • Plastics in gull pellets reflect contamination of their avian prey. • 79% of white-faced storm petrels in the Northeast Atlantic contain plastics. • Gull pellets are suitable to monitor the little known subtropical NE Atlantic.

  18. Genetic factors have a major effect on growth, number of vertebrae and otolith shape in Atlantic herring (Clupea harengus).

    Science.gov (United States)

    Berg, Florian; Almeland, Oda W; Skadal, Julie; Slotte, Aril; Andersson, Leif; Folkvord, Arild

    2018-01-01

    Atlantic herring, Clupea harengus, have complex population structures. Mixing of populations is known, but the extent of connectivity is still unclear. Phenotypic plasticity results in divergent phenotypes in response to environmental factors. A marked salinity gradient occurs from Atlantic Ocean (salinity 35) into the Baltic Sea (salinity range 2-12). Herring from both habitats display phenotypic and genetic variability. To explore how genetic factors and salinity influence phenotypic traits like growth, number of vertebrae and otolith shape an experimental population consisting of Atlantic purebreds and Atlantic/Baltic F1 hybrids were incubated and co-reared at two different salinities, 16 and 35, for three years. The F1-generation was repeatedly sampled to evaluate temporal variation. A von Bertalanffy growth model indicated that reared Atlantic purebreds had a higher maximum length (26.2 cm) than Atlantic/Baltic hybrids (24.8 cm) at salinity 35, but not at salinity 16 (25.0 and 24.8 cm, respectively). In contrast, Atlantic/Baltic hybrids achieved larger size-at-age than the wild caught Baltic parental group. Mean vertebral counts and otolith aspect ratios were higher for reared Atlantic purebreds than Atlantic/Baltic hybrids, consistent with the differences between parental groups. There were no significant differences in vertebral counts and otolith aspect ratios between herring with the same genotype but raised in different salinities. A Canonical Analysis of Principal Coordinates was applied to analyze the variation in wavelet coefficients that described otolith shape. The first discriminating axis identified the differences between Atlantic purebreds and Atlantic/Baltic hybrids, while the second axis represented salinity differences. Assigning otoliths based on genetic groups (Atlantic purebreds vs. Atlantic/Baltic hybrids) yielded higher classification success (~90%) than based on salinities (16 vs. 35; ~60%). Our results demonstrate that otolith shape and

  19. Genetic factors have a major effect on growth, number of vertebrae and otolith shape in Atlantic herring (Clupea harengus.

    Directory of Open Access Journals (Sweden)

    Florian Berg

    Full Text Available Atlantic herring, Clupea harengus, have complex population structures. Mixing of populations is known, but the extent of connectivity is still unclear. Phenotypic plasticity results in divergent phenotypes in response to environmental factors. A marked salinity gradient occurs from Atlantic Ocean (salinity 35 into the Baltic Sea (salinity range 2-12. Herring from both habitats display phenotypic and genetic variability. To explore how genetic factors and salinity influence phenotypic traits like growth, number of vertebrae and otolith shape an experimental population consisting of Atlantic purebreds and Atlantic/Baltic F1 hybrids were incubated and co-reared at two different salinities, 16 and 35, for three years. The F1-generation was repeatedly sampled to evaluate temporal variation. A von Bertalanffy growth model indicated that reared Atlantic purebreds had a higher maximum length (26.2 cm than Atlantic/Baltic hybrids (24.8 cm at salinity 35, but not at salinity 16 (25.0 and 24.8 cm, respectively. In contrast, Atlantic/Baltic hybrids achieved larger size-at-age than the wild caught Baltic parental group. Mean vertebral counts and otolith aspect ratios were higher for reared Atlantic purebreds than Atlantic/Baltic hybrids, consistent with the differences between parental groups. There were no significant differences in vertebral counts and otolith aspect ratios between herring with the same genotype but raised in different salinities. A Canonical Analysis of Principal Coordinates was applied to analyze the variation in wavelet coefficients that described otolith shape. The first discriminating axis identified the differences between Atlantic purebreds and Atlantic/Baltic hybrids, while the second axis represented salinity differences. Assigning otoliths based on genetic groups (Atlantic purebreds vs. Atlantic/Baltic hybrids yielded higher classification success (~90% than based on salinities (16 vs. 35; ~60%. Our results demonstrate that

  20. Evidence from the past: exploitation as cause of commercial extinction of autumn-spawning herring in the Gulf of Riga, Baltic Sea

    DEFF Research Database (Denmark)

    MacKenzie, Brian R; Ojaveer, Henn

    2018-01-01

    Historical marine ecology has shown that many exploited animal populations declined before their abundance was quantified by scientists. This situation applies for autumn-spawning herring (Clupea harengus) in the Baltic Sea. This stock used to be the dominant spawning group of herring in the early...... and biological data and conduct population development simulations to evaluate the hypothesis that exploitation may have been sufficient to lead the stock towards commercial extinction. We found that the estimated exploitation pattern, including exploitation of juveniles, was unsustainable and led to stock...

  1. A phenomenological study of ripening of salted herring. Assessing homogeneity of data from different countries and laboratories

    DEFF Research Database (Denmark)

    Bro, R.; Nielsen, Henrik Hauch; Stefánsson, G.

    2002-01-01

    of treatments and analyzed in different laboratories. The question considered here is whether these data can be assumed to be one homogeneous set of data pertaining to ripening of salted herring or whether data from different labs, stocks, etc. must be considered independently. This is of importance for further...... easily be envisioned, it was exactly the need for a more intuitive and visual test that prompted this work, developing different exploration tools that visually make it clear how well the data can be assumed to derive from the same population. Subsequently analyzing the data as one homogeneous group...

  2. Exploring the multidimensional nature of stock structure: a case study on herring dynamics in a transition area

    DEFF Research Database (Denmark)

    Worsøe Clausen, Lotte

    occupy areas without much environmental structuring and extensive mixing between populations occur. Many species of marine fishes have the capacity of dispersing over vast geographical areas, either passively by drifting eggs and larvae following ocean currents, or actively by migration of juveniles...... will aid a sustainable aggregated management of a fishery on a mixed herring stock. It will facilitate protecting the weaker populations from over harvesting in a mixed fishery and thus maintain the diversity and in turn the resilience of the stock to a fishery...

  3. Field Metabolic Rate Is Dependent on Time-Activity Budget in Ring-Billed Gulls (Larus delawarensis Breeding in an Anthropogenic Environment.

    Directory of Open Access Journals (Sweden)

    Sarah C Marteinson

    Full Text Available Environmental and behavioral factors have long been assumed to affect variation in avian field metabolic rate (FMR. However, due to the difficulties in measuring continuous behavior of birds over prolonged periods of time, complete time-activity budgets have rarely been examined in relation to FMR. Our objective was to determine the effect of activity (measured by detailed time-activity budgets and a series of extrinsic and intrinsic factors on FMR of the omnivorous ring-billed gull (Larus delawarensis. The experiment was conducted during the incubation period when both members of the pair alternate between attending the nest-site and leaving the colony to forage in aquatic and anthropogenic environments (city, agricultural. FMR was determined using the doubly labeled water method. Time-activity budgets were extrapolated from spatio-temporal data (2-5 days obtained from bird-borne GPS data loggers. Gulls had low FMRs compared to those predicted by allometric equations based on recorded FMRs from several seabird species. Gulls proportioned their time mainly to nest-site attendance (71% of total tracking time, which reduced FMR/g body mass, and was the best variable explaining energy expenditure. The next best variable was the duration of foraging trips, which increased FMR/g; FMR/g was also elevated by the proportion of time spent foraging or flying (17% and 8% of tracking time respectively. Most environmental variables measured did not impact FMR/g, however, the percent of time birds were subjected to temperatures below their lower critical temperature increased FMR. Time-activity budgets varied between the sexes, and with temperature and capture date suggesting that these variables indirectly affected FMR/g. The gulls foraged preferentially in anthropogenic-related habitats, which may have contributed to their low FMR/g due to the high availability of protein- and lipid-rich foods. This study demonstrates that activities were the best

  4. Limnology of Eifel maar lakes

    National Research Council Canada - National Science Library

    Scharf, Burkhard W; Björk, Sven

    1992-01-01

    ... & morphometry - Physical & chemical characteristics - Calcite precipitation & solution in Lake Laacher See - Investigations using sediment traps in Lake Gemundener Maar - Phytoplankton of Lake Weinfelder Maar...

  5. Identification and Characterization of Main Allergic Proteins in Cooked Wolf Herring Fish.

    Science.gov (United States)

    Mohamadi, Mohsen; Falak, Reza; Mokhtarian, Kobra; Khoramizadeh, Mohammad Reza; Sadroddiny, Esmaeil; Kardar, Gholam Ali

    2016-10-01

    Our aim in this study was to identify and characterize allergic proteins in cooked wolf herring fish. We heated the crude extract alternatively at 50, 60, 70, 80, 90, and 100°C for one hour and results were compared by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Also, proteins were immunoblotted with fish-sensitive patients' sera. The major allergenic proteins were identified via mass spectrometry. These allergenic proteins were then purified by anion exchange chromatography and the IgE-immunoreactivity of the fractions was compared with the crude extracts via disk enzyme-linked immunosorbent assay (ELISA). SDS-PAGE of the crude extract showed more than 15 distinct protein bands. Five of these proteins, with apparent molecular weights of 12, 18, 24, 38, and 51 kDa, were only observed in the 100°C heated extract. Immunoblotting of the heated extract revealed that the 12 and 51 kDa proteins were IgE-immunoreactive with 88 percent of fish-sensitive patient sera while the 24 and 38 kDa proteins reacted with 33.3 and 55.5 percent of fish-sensitive patient sera, respectively. Mass spectrometry of the 12, 38, and 51 kDa proteins revealed that all three were parvalbumin oligomers. Disk ELISA results showed that 20 of 25 and 14 of 25 fish-allergic patients' sera were IgE-reactive with purified oligomeric parvalbumin-coated and crude extract-coated disks, respectively. Parvalbumin and its oligomers are the main allergenic molecules in cooked fish. Therefore, an enriched or purified fraction containing this protein could be a useful source of allergen for applications in ELISA-based immunoassays and could discriminate fish-allergic patients who can tolerate cooked fish from those who cannot.

  6. Bathymetry of Lake Erie and Lake Saint Clair

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Erie and Lake Saint Clair has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and...

  7. Allelic variability in species and stocks of Lake Superior ciscoes (Coregoninae)

    Science.gov (United States)

    Todd, Thomas N.

    1981-01-01

    Starch gel electrophoresis was used as a means of recognizing species and stocks in Lake Superior Coregonus. Allelic variability at isocitrate dehydrogenase and glycerol-3-phosphate dehydrogenase loci was recorded for samples of lake herring (Coregonus artedii), bloater (C. hoyi), kiyi (C. kiyi), and shortjaw cisco (C. zenithicus) from five Lake Superior localities. The observed frequencies of genotypes within each subsample did not differ significantly from those expected on the basis of random mating, and suggested that each subsample represented either a random sample from a larger randomly mating population or an independent and isolated subpopulation within which mating was random. Significant contingency X2 values for comparisons between both localities and species suggested that more than one randomly mating population occurred among the Lake Superior ciscoes, but did not reveal how many such populations there were. In contrast to the genetic results of this study, morphology seems to be a better descriptor of cisco stocks, and identification of cisco stocks and species will still have to be based on morphological criteria until more data are forthcoming. Where several species are sympatric, management should strive to preserve the least abundant. Failure to do so could result in the extinction or depletion of the rarer forms.

  8. Identifying molecular effects of diet through systems biology: influence of herring diet on sterol metabolism and protein turnover in mice.

    Directory of Open Access Journals (Sweden)

    Intawat Nookaew

    Full Text Available BACKGROUND: Changes in lifestyle have resulted in an epidemic development of obesity-related diseases that challenge the healthcare systems worldwide. To develop strategies to tackle this problem the focus is on diet to prevent the development of obesity-associated diseases such as cardiovascular disease (CVD. This will require methods for linking nutrient intake with specific metabolic processes in different tissues. METHODOLOGY/PRINCIPAL FINDING: Low-density lipoprotein receptor-deficient (Ldlr -/- mice were fed a high fat/high sugar diet to mimic a westernized diet, being a major reason for development of obesity and atherosclerosis. The diets were supplemented with either beef or herring, and matched in macronutrient contents. Body composition, plasma lipids and aortic lesion areas were measured. Transcriptomes of metabolically important tissues, e.g. liver, muscle and adipose tissue were analyzed by an integrated approach with metabolic networks to directly map the metabolic effects of diet in these different tissues. Our analysis revealed a reduction in sterol metabolism and protein turnover at the transcriptional level in herring-fed mice. CONCLUSION: This study shows that an integrated analysis of transcriptome data using metabolic networks resulted in the identification of signature pathways. This could not have been achieved using standard clustering methods. In particular, this systems biology analysis could enrich the information content of biomedical or nutritional data where subtle changes in several tissues together affects body metabolism or disease progression. This could be applied to improve diets for subjects exposed to health risks associated with obesity.

  9. Histopathology and cytogenetic evaluation of Pacific herring larvae exposed to petroleum hydrocarbons in the laboratory or in Prince William Sound, Alaska, after the Exxon Valdez oil spill

    International Nuclear Information System (INIS)

    Marty, G.D.; Hinton, D.E.; Brown, E.D.

    1997-01-01

    Following the Exxon Valdez oil spill in Prince William Sound, Alaska, Pacific herring larvae samples from oiled sites showed ascites, pericardial edema, and genotoxic damage. Laboratory study confirmed that these lesions were consistent with oil exposure. In a laboratory experiment, Pacific herring eggs were exposed to an oil-water dispersion of Prudhoe Bay crude oil and sampled for histopathology less than 24 h after hatching. Effects were significant at the 0.48 mg/L dose. Lesions included ascites, heptocellular vacuolar change and degeneration or necrosis of skeletal myocytes, retinal cells, and developing brain cells. Lesions in field-sampled larvae were consistent with higher mortality rates documented in larvae from oiled sites. In both field and laboratory experiments, ascites was the most significant lesion related to oil exposure. Decreased growth in larvae from oiled sites was also consistent with findings in three other laboratory studies with Pacific herring. This study concluded that if a large proportion of a population is exposed to contamination during early life stages, impacts on subsequent recruitment may be significant. However, estimates of the proportion of Pacific herring year-class affected by the Exxon Valdez oil spill vary from 4 per cent to 50 per cent. Since recruitment of the 1989 year-class was also poor in Sitka Sound (the control site), it was suggested that oceanic variables might have been more significant in limiting recruitment of the 1989 year-class in Prince William Sound than was the oil spill. 40 refs., 3 tabs., 7 figs

  10. Effects of exotic fish farms on bird communities in lake and marine ecosystems

    Science.gov (United States)

    Jiménez, Jaime E.; Arriagada, Aldo M.; Fontúrbel, Francisco E.; Camus, Patricio A.; Ávila-Thieme, M. Isidora

    2013-08-01

    Salmon farming is a widespread activity around the world, also known to promote diverse environmental effects on aquatic ecosystems. However, information regarding the impact of salmon farming on bird assemblages is notably scarce. We hypothesize that salmon farming, by providing food subsidies and physical structures to birds, will change their local community structure. To test this hypothesis, we conducted a seasonal monitoring of bird richness, abundance, and composition at paired salmon pen and control plots in two marine and two lake sites in southern Chile, from fall 2002 to summer 2004. Overall, salmon farming had no significant effects on species richness, but bird abundance was significantly and noticeably higher in salmon pens than in controls. Such aggregation was mainly accounted for by the trophic guilds of omnivores, diving piscivores, carrion eaters, and perching piscivores, but not by invertebrate feeders, herbivores, and surface feeders. Species composition was also significantly and persistently different between salmon pens and controls within each lake or marine locality. The patterns described above remained consistent across environment types and seasons indicating that salmon farming is changing the community structure of birds in both lake and marine habitats by promoting functional and aggregation responses, particularly by favoring species with broader niches. Such local patterns may thus anticipate potential threats from the ongoing expansion of the salmon industry to neighboring areas in Chile, resulting in regional changes of bird communities, toward a less diverse one and dominated by opportunistic, common, and generalist species such as gulls, vultures, and cormorants.

  11. Lake or Pond WBID

    Data.gov (United States)

    Vermont Center for Geographic Information — The VT DEC (Vermont Department of Environmental Conservation) manages an inventory of lake and pond information. The "Lakes and Ponds Inventory" stores the Water...

  12. National Lakes Assessment Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The National Lakes Assessment (NLA) is a first-ever statistically-valid survey of the biological condition of lakes and reservoirs throughout the U.S. The U.S....

  13. DNR 24K Lakes

    Data.gov (United States)

    Minnesota Department of Natural Resources — Medium scale lake polygons derived from the National Wetlands Inventory (NWI) polygons and MnDOT Basemap lake delineations. Integrated with the DNR 24K Streams...

  14. Selection by higher-order effects of salinity and bacteria on early life-stages of Western Baltic spring-spawning herring.

    Science.gov (United States)

    Poirier, Maude; Listmann, Luisa; Roth, Olivia

    2017-07-01

    Habitat stratification by abiotic and biotic factors initiates divergence of populations and leads to ecological speciation. In contrast to fully marine waters, the Baltic Sea is stratified by a salinity gradient that strongly affects fish physiology, distribution, diversity and virulence of important marine pathogens. Animals thus face the challenge to simultaneously adapt to the concurrent salinity and cope with the selection imposed by the changing pathogenic virulence. Western Baltic spring-spawning herring ( Clupea harengus ) migrate to spawning grounds characterized by different salinities to which herring are supposedly adapted. We hypothesized that herring populations do not only have to cope with different salinity levels but that they are simultaneously exposed to higher-order effects that accompany the shifts in salinity, that is induced pathogenicity of Vibrio bacteria in lower saline waters. To experimentally evaluate this, adults of two populations were caught in their spawning grounds and fully reciprocally crossed within and between populations. Larvae were reared at three salinity levels, representing the spawning ground salinity of each of the two populations, or Atlantic salinity conditions resembling the phylogenetic origin of Clupea harengus . In addition, larvae were exposed to a Vibrio spp . infection. Life-history traits and gene expression analysis served as response variables. Herring seem adapted to Baltic Sea conditions and cope better with low saline waters. However, upon a bacterial infection, herring larvae suffer more when kept at lower salinities implying reduced resistance against Vibrio or higher Vibrio virulence. In the context of recent climate change with less saline marine waters in the Baltic Sea, such interactions may constitute key future stressors.

  15. Temporal trends in dioxins (polychlorinated dibenzo-p-dioxin and dibenzofurans) and dioxin-like polychlorinated biphenyls in Baltic herring (Clupea harengus).

    Science.gov (United States)

    Miller, Aroha; Hedman, Jenny E; Nyberg, Elisabeth; Haglund, Peter; Cousins, Ian T; Wiberg, Karin; Bignert, Anders

    2013-08-15

    Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyl (dl-PCBs) concentrations in Baltic herring (Clupea harengus) have been relatively stable since the mid to late 1990s. It is unclear why concentrations in Baltic herring are not following the observed decreases in other environmental matrices. Here, changes in long-term temporal trends in Baltic herring were examined. A number of biological variables were examined alongside the temporal trends to investigate whether fish biology e.g., growth (length, weight, age), lipid content, reproductive phase or fishing date may provide an explanation for the temporal trends observed. Significant (p<0.05) decreasing trends were observed for PCDD/F toxic equivalents (TEQPCDD/F) at three of the four sites (lipid weight (lw) and wet weight (ww), Swedish west coast lw only); however, other TEQ values e.g., TEQPCDD, TEQPCDF, TEQdl-PCB, TEQPCDD/F+dl-PCB were inconsistent, decreasing at some sites but not others. In the most recent 10 years of data, fewer significant decreases were seen overall. Over the examined time period, significant decreases (Bothnian Bay, p<0.01, southern Baltic Proper, p<0.02) and increases (Swedish west coast, p<0.02) in lipid content, growth dilution or lack thereof, and significant changes in age were observed. However herring were not randomly selected which biases this result. Continual efforts to decrease PCDD/F and dl-PCB emissions and to locate/reduce hotspots are necessary, while bearing in mind that herring biology may be impeding faster decreases of these chemicals. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Evaluating signals of oil spill impacts, climate, and species interactions in Pacific herring and Pacific salmon populations in Prince William Sound and Copper River, Alaska.

    Directory of Open Access Journals (Sweden)

    Eric J Ward

    Full Text Available The Exxon Valdez oil spill occurred in March 1989 in Prince William Sound, Alaska, and was one of the worst environmental disasters on record in the United States. Despite long-term data collection over the nearly three decades since the spill, tremendous uncertainty remains as to how significantly the spill affected fishery resources. Pacific herring (Clupea pallasii and some wild Pacific salmon populations (Oncorhynchus spp. in Prince William Sound declined in the early 1990s, and have not returned to the population sizes observed in the 1980s. Discerning if, or how much of, this decline resulted from the oil spill has been difficult because a number of other physical and ecological drivers are confounded temporally with the spill; some of these drivers include environmental variability or changing climate regimes, increased production of hatchery salmon in the region, and increases in populations of potential predators. Using data pre- and post-spill, we applied time-series methods to evaluate support for whether and how herring and salmon productivity has been affected by each of five drivers: (1 density dependence, (2 the EVOS event, (3 changing environmental conditions, (4 interspecific competition on juvenile fish, and (5 predation and competition from adult fish or, in the case of herring, humpback whales. Our results showed support for intraspecific density-dependent effects in herring, sockeye, and Chinook salmon, with little overall support for an oil spill effect. Of the salmon species, the largest driver was the negative impact of adult pink salmon returns on sockeye salmon productivity. Herring productivity was most strongly affected by changing environmental conditions; specifically, freshwater discharge into the Gulf of Alaska was linked to a series of recruitment failures-before, during, and after EVOS. These results highlight the need to better understand long terms impacts of pink salmon on food webs, as well as the

  17. Intra-clutch and inter-colony variability in element concentrations in eggshells of the black-headed gull, Chroicocephalus ridibundus, in northern Poland.

    Science.gov (United States)

    Kitowski, Ignacy; Indykiewicz, Piotr; Wiącek, Dariusz; Jakubas, Dariusz

    2017-04-01

    Eggshells are good bioindicators of environmental contamination, and therefore, the concentrations of 17 trace elements in 87 eggshells of black-headed gulls, Chroicocephalus ridibundus, were determined in five breeding colonies in an area dominated by farmland in northern Poland. The intra-clutch variability in the eggshell concentrations of heavy metals and other elements was also investigated, and the concentrations of the elements showed the following pattern: Ca > Mg > Sr > Fe > Zn > Al > Cr > Se > Mn > Cu > Pb > As > Ni > Mo = V > Sc > Cd. The concentrations of Fe, Al, and Mn decreased with the order in which the eggs were laid, but Sr concentrations increased. In contrast, the concentration of Cu significantly increased with the laying date. The concentrations of all elements significantly differed among the studied colonies; the highest concentration of eight elements was found in the eggshells from the Kusowo colony, which may have resulted from the intensive use of fertilizers, manure, and slurry in the surrounding agricultural region. The concentrations of Mg, Sr, and Zn in the eggshells from Skoki Duże were higher than those of the other studied colonies, which may have occurred because the gulls were nesting in a functioning gravel pit; soil and the parent rock are natural reservoirs of these elements. The observed element levels indicate that the environment where the black-headed gull eggs were formed, i.e., primarily near the breeding colonies, remains in a relatively unpolluted state, which was reflected by the low levels of Cd, Ni, and Pb and the lack of measurable levels of Hg.

  18. Description and proposed life cycle of Maritrema novaezealandensis n. sp. (Microphallidae) parasitic in red-billed gulls, Larus novaehollandiae scopulinus, from Otago Harbor, South Island, New Zealand

    DEFF Research Database (Denmark)

    Martorelli, Sergio R; Fredensborg, Brian Lund; Mouritsen, Kim Nørgaard

    2004-01-01

    Maritrema novaezealandensis n. sp. is described from Otago Harbor, South Island, New Zealand, on the basis of adult specimens collected from the Red-billed gull, Larus novaehollandiae scopulinus, and excysted metacercariae obtained from crabs. It belongs to the "eroliae group" and differs from...... snail, Zeacumantus subcarinatus, in which the cercarial stage is produced in sporocysts located within the gonad of the snail. At least 3 crab species (Hemigrapsus crenulatus, Macrophtalmus hirtipes, and Halicarcinus whitei) and several species of amphipods act as second intermediate hosts...

  19. Yolk testosterone affects growth and promotes individual-level consistency in behavioral lateralization of yellow-legged gull chicks.

    Science.gov (United States)

    Possenti, Cristina Daniela; Romano, Andrea; Caprioli, Manuela; Rubolini, Diego; Spiezio, Caterina; Saino, Nicola; Parolini, Marco

    2016-04-01

    Behavioral lateralization is common in animals and may be expressed at the individual- and at the population-level. The ontogenetic processes that control lateralization, however, are largely unknown. Well-established sex-dependence in androgen physiology and sex-dependent variation in lateralization have led to the hypothesis that testosterone (T) has organizational effects on lateralization. The effects of T exposure in early life on lateralization can be efficiently investigated by manipulating T levels in the cleidoic eggs of birds, because the embryo is isolated from maternal and sibling physiological interference, but this approach has been adopted very rarely. In the yellow-legged gull (Larus michahellis) we increased yolk T concentration within the physiological limits and tested the effects on the direction of lateralization in two functionally fundamental behaviors (begging for parental care and escape to cover) of molecularly sexed hatchlings. We also speculated that T may intervene in regulating consistency, rather than direction of lateralization, and therefore tested if T affected the 'repeatability' of lateral preference in consecutive behavioral trials. T treatment had no effect on the direction of lateralization, but enhanced the consistency of lateral preference in escape responses. Sex did not predict lateralization. Neither behavior was lateralized at the population-level. We therefore showed for the first time in any species an effect of egg T on consistency in lateralization. The implications of the effect of T for the evolution of trade-offs in maternal allocation of egg hormones, and the evolutionary interpretations of findings from our studies on lateralization among unmanipulated birds are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Education in and for the Outdoors. Report of the National Conference on Outdoor Education (Kellogg Gull Lake Biological Station, Hickory Corners, Michigan, May 2-4, 1962).

    Science.gov (United States)

    American Association for Health, Physical Education, and Recreation, Washington, DC.

    The two board aspects of outdoor education considered in this document are education in the outdoors, using the natural environment as a laboratory for learning, and education for the outdoors, with a focus on teaching skills and appreciations for outdoor recreation. Conference procedures, keynote addresses, current practices, contributions to…

  1. Letna Dinamika Pojavljanja Vodnih Ptic Na Reki Dravi Med Mariborskim Jezerom In Jezom Melje (Sv Slovenija / Yearly dynamics of waterbirds’ occurrence on the Drava River between Lake Maribor and Melje Dam (NE Slovenia

    Directory of Open Access Journals (Sweden)

    Logar Katja

    2014-11-01

    Full Text Available Between April 2007 and April 2008, 40 systematic waterbird counts were conducted on the Drava River between Lake Maribor and the Melje Dam (length 8.5 km, area 155 ha to determine the specific composition, abundance and seasonal dynamics of bird occurrence. Between October and May, counts were conducted every week, whereas between June and September they were carried out once every two weeks. In total, 26,803 individuals of 30 species were counted. The number of waterbirds and diversity of species were the highest from late December to late February, when more than 1,000 individuals were regularly present in the area. Waterbirds were distributed along the river unequally, with the highest number of birds present yearround in the city centre and in the first counting sector of Lake Maribor. The Mallard Anas platyrhynchos and Mute Swan Cygnus olor were recorded during every count, while occurrence frequency was greater than 50% in another 10 species. Dominant species in terms of percentage composition were Mallard, Black-headed Gull Chroicocephalus ridibundus, Coot Fulica atra, Mute Swan, Pochard Aythya ferina and Tufted Duck Ay. fuligula. Mute Swan and Mallard were the only breeding waterbirds in the study area. Both the total number of waterbirds and the highest daily total in the first two counting sectors were greater between October and March 1992/93 than in our study. The decline in numbers was the greatest for Mallard, Pochard and Tufted Duck, while an increase was noted in Mute Swan and Yellow-legged / Caspian Gull Larus michahellis / cachinnans. The total number of waterbirds and the number of some species in the study area were significantly higher than expected solely based on its length compared to the length of the lowland Drava in Slovenia (125.7 km. The study area is conservationally important for Pochard, Tufted Duck and Black-headed Gull

  2. Long-distance flights and high-risk breeding by nomadic waterbirds on desert salt lakes.

    Science.gov (United States)

    Pedler, Reece D; Ribot, Raoul F H; Bennett, Andrew T D

    2018-02-01

    Understanding and conserving mobile species presents complex challenges, especially for animals in stochastic or changing environments. Nomadic waterbirds must locate temporary water in arid biomes where rainfall is highly unpredictable in space and time. To achieve this they need to travel over vast spatial scales and time arrival to exploit pulses in food resources. How they achieve this is an enduring mystery.  We investigated these challenges in the colonial-nesting Banded Stilt (Cladorhynchus leucocephalus), a nomadic shorebird of conservation concern. Hitherto, Banded Stilts were hypothesized to have only 1-2 chances to breed during their long lifetime, when flooding rain fills desert salt lakes, triggering mass-hatching of brine shrimp. Over 6 years, we satellite tagged 57 individuals, conducted 21 aerial surveys to detect nesting colonies on 14 Australian desert salt lakes, and analyzed 3 decades of Landsat and MODIS satellite imagery to quantify salt-lake flood frequency and extent. Within days of distant inland rainfall, Banded Stilts flew 1,000-2,000 km to reach flooded salt lakes. On arrival, females laid over half their body weight in eggs. We detected nesting episodes across the species' range at 7 times the frequency reported during the previous 80 years. Nesting colonies of thousands formed following minor floods, yet most were subsequently abandoned when the water rapidly evaporated prior to egg hatching. Satellite imagery revealed twice as many flood events sufficient for breeding-colony initiation as recorded colonies, suggesting that nesting at remote sites has been underdetected. Individuals took risk on uncertain breeding opportunities by responding to frequent minor flood events between infrequent extensive flooding, exemplifying the extreme adaptability and trade-offs of species exploiting unstable environments. The conservation challenges of nest predation by overabundant native gulls and anthropogenic modifications to salt lakes filling

  3. Egg-larval mortality of Pacific herring in Prince William Sound, Alaska, after the Exxon Valdez oil spill

    International Nuclear Information System (INIS)

    McGurk, M. D.; Brown, E. D.

    1996-01-01

    Experiments were carried out to test the hypothesis that instantaneous daily rates of egg-larval mortality of Pacific herring were higher at two oil-exposed sites than at two other sites not so exposed. Results showed that egg-larval mortality was twice as great in the oil-exposed areas as in the two non-oiled areas. Larval growth rates were also severely affected; they were about half of those measured in populations from other areas of the north Pacific Ocean. A cautionary note was introduced to the effect that the differences in the egg-larval mortality between oiled and control sites may have been influenced by differences in egg dessication, predation, and wave scouring, hence these results should not be construed as conclusive evidence of oil spill damage. 40 refs., 6 figs

  4. Genetic and environmental correlates of morphological variation in a marine fish: the case of Baltic Sea herring ( Clupea harengus )

    DEFF Research Database (Denmark)

    Jørgensen, H.B.H.; Pertoldi, C.; Hansen, Michael Møller

    2008-01-01

    Baltic Sea herring (Clupea harengus) have been shown to exhibit morphological differences across the marked salinity and temperature gradients in the region. Here we analyse genetic (nine microsatellite loci), morpho metric (skull shape), and meristic (pectoral fin rays and number of vertebrae...... and plastic responses. Skull shape, including and excluding size variation, differed significantly among samples, both temporally and spatially. Genetic and morphometric distances were correlated, especially when size variation was excluded from the analysis. When size variation was included, skull shape...... variation was more closely correlated with environmental distances among spawning locations. Vertebrate number differed among samples and was correlated with environmental distances, whereas the number of fin rays was not. Genetic and geographic distances among samples were not correlated....

  5. The amount of food ingested in a single meal by rainbow trout offered chopped herring, dry and wet diets

    Science.gov (United States)

    Ruohonen; Grove; McIlroy

    1997-07-01

    Two-year-old 1·5-kg rainbow trout were held in cages and conditioned by feeding either on low-fat chopped herring (H trout) or dry pellets (P trout) for 15 weeks. Their satiation amounts were then determined under standard conditions. On a wet weight basis H trout ate 2·5-3·5 times more food than P trout; this was sufficient to compensate for the high water content of herring and thereby maintain the dry matter intake. When P trout were offered herring (PH trout) they consumed more food than when offered dry pellets but not as much as H trout. Stomach capacity restricted the intake and their dry matter intake was reduced by c. 40%. When H trout were offered dry pellets (HP trout) they adjusted their intake immediately close to the level of P trout although their larger stomachs could have accommodated more than twice this volume of dry food. The return of appetite after a satiation meal was almost linear with time. Appetite increased at c. 556 mg g-1 body weight h-1 for H trout and at 142 mg g-1 bw h-1 for P trout. The return of appetite in PH trout was significantly slower (c. 370 mg g-1 bw h-1) than in H trout; the previous dietary history of the PH trout limited their capacity to process larger volumes of wet food in a single meal. Fish offered dry diet (P and HP trout) had similar rates of appetite return despite their previous feeding history suggesting that the property of the dry feed itself might limit meal size. The total gastric emptying time of diets of similar dry matter content (with and without large amounts of water) was similar, but the delay time before gastric emptying starts tended to be longer for dry diets. Dry pellets appear to impose a demand for water that prolongs the gastric delay. This water demand is met partly by drinking since the trout fed on dry pellets drank significantly more (436±189 mg kg-1 h-1) than unfed and herring-fed trout which drank little or not at all (65±113 and 70±66 mg kg-1 h-1 respectively). Dietary water

  6. Effect of spatial differences in growth on distribution of seasonally co-occurring herring Clupea harengus stocks

    DEFF Research Database (Denmark)

    Worsøe Clausen, Lotte; Stæhr, Karl-Johan; Rindorf, Anna

    2015-01-01

    The mechanisms most likely to determine the distribution of the two major herring Clupea harengus stocks in their common early summer feeding ground in the eastern North Sea, Skagerrak and Kattegat were investigated through analysis of acoustic survey data from six consecutive years. No change...... was detected in biomass of North Sea autumn spawning C. harengus (NSAS) over time, whereas the biomass of western Baltic spring spawning C. harengus (WBSS) declined severely. Analyses of centre of abundance by stock showed no change in NSAS distribution, whereas the WBSS changed to a more western distribution...... Kattegat. The westward movement of spring spawners over time suggests that growth rate and possibly density of conspecifics influence the migration pattern and distribution of C. harengus in the area. In contrast, there was no evidence to suggest that distribution was constant over time within stocks...

  7. Kinetics of viral load and erythrocytic inclusion body formation in pacific herring artificially infected with erythrocytic necrosis virus

    Science.gov (United States)

    Glenn, Jolene A.; Emmenegger, Eveline J.; Grady, Courtney A.; Roon, Sean R.; Gregg, Jacob L.; Conway, Carla M.; Winton, James R.; Hershberger, Paul K.

    2012-01-01

    Viral erythrocytic necrosis (VEN) is a condition that affects marine and anadromous fish species, including herrings and salmonids, in the Atlantic and Pacific oceans. Infection is frequently associated with severe anemia and causes episodic mortality among wild and hatchery fish when accompanied by additional stressors; VEN can be presumptively diagnosed by (1) light microscopic identification of a single characteristic—a round, magenta-colored, 0.8-μm-diameter inclusion body (IB) within the cytoplasm of erythrocytes and their precursors on Giemsa-stained blood films; or (2) observation (via transmission electron microscopy [TEM]) of the causative iridovirus, erythrocytic necrosis virus (ENV), within erythrocytes or their precursors. To better understand the kinetics of VEN, specific-pathogen-free Pacific herring Clupea pallasii were infected with ENV by intraperitoneal injection. At 1, 4, 7, 10, 14, 21, and 28 d postexposure, samples of blood, spleen, and kidney were collected and assessed (1) via light microscopy for the number of intracytoplasmic IBs in blood smears and (2) via TEM for the number of virions within erythrocytes. The mean prevalence of intracytoplasmic IBs in the blood cells increased from 0% at 0–4 d postexposure to 94% at 28 d postexposure. Viral load within circulating red blood cells peaked at 7 d postexposure, fell slightly, and then reached a plateau. However, blood cells observed within the kidney and spleen tissues demonstrated high levels of ENV between 14 and 28 d postexposure. The results indicate that the viral load within erythrocytes does not correlate well with IB prevalence and that the virus can persist in infected fish for more than 28 d.

  8. Impaired immune function in seals and laboratory rats exposed to dioxin-like compounds from Baltic herring

    Energy Technology Data Exchange (ETDEWEB)

    Ross, P.S. [Seal Rehabilitation and Research Centre, Pieterburen (Netherlands)]|[National Inst. of Public Health and Environmental Protection, Bilthoven (Netherlands); Swart, R.L. de [Seal Rehabilitation and Research Centre, Pieterburen (Netherlands)]|[Erasmus Univ., Rotterdam (Netherlands); Timmerman, H.H.; Loveren, H. van [National Inst. of Public Health and Environmental Protection, Bilthoven (Netherlands); Osterhaus, A.D.M.E. [Seal Rehabilitation and Research Centre, Pieterburen (Netherlands)]|[National Inst. of Public Health and Environmental Protection, Bilthoven (Netherlands)]|[Erasmus Univ., Rotterdam (Netherlands)

    1995-12-31

    Complex mixtures of lipophilic contaminants have been shown to affect certain top predators in the aquatic food chain, including seals. A recent demonstration that harbor seals (Phoca vitulina) fed Baltic Sea herring displayed impaired natural killer cell activity and T-lymphocyte function represented the first demonstration of immunotoxicity induced by ambient levels of contaminants in the environment. While these animals had a lower ability to respond to immunizations with inactivated vaccines, specific antibody responses, and in vitro antigen-specific lymphoproliferative responses, obvious constraints limited the ability to extend these results with host resistance tests or an evaluation of thymus and other lymphoid organs. The authors therefore set up a parallel study by exposing pregnant laboratory rats to the same Baltic herring contaminant mixture as received the seals. They then examined immune function parameters and host resistance to virus infection. As in the seals, rat pups of the Baltic group had impaired T-lymphocyte function. In addition, thymus cells and/or their precursors appeared to be targeted, as their numbers and function were reduced in the rats. Following challenge with rat cytomegalovirus in a host resistance study, rat pups in the Baltic group had impaired natural killer cell responses to the virus infection, and lower specific CD8 + (cytotoxic T-lymphocyte) responses following in vitro stimulation. By extrapolation, these results suggest that the impaired immune responses observed in the Baltic group of seals may lead to a less effective defense against virus infections in marine mammals inhabiting polluted coastal waters. Toxicological profiles and results of both the captive seal and laboratory rat experiments tend to implicate the 2,3,7,8-TCDD-like PCB, dioxin and furan congeners in the immunosuppression, and point to a major role for the PCBs.

  9. Biological transport of persistent organic pollutants (POPs) to Lake Ellasjoeen, Bjoernoeya (Bear Island), Norway

    Energy Technology Data Exchange (ETDEWEB)

    Evenset, A.; Christensen, G. [Akvaplan-niva, Tromso (Norway); Kallenborn, R. [Norwegian Inst. for Air Research, Kjeller (Norway); Herzke, D. [Norwegian Inst. for Air Research, Tromso (Norway)

    2004-09-15

    During recent years, multidisciplinary studies have been carried out on Bjoernoeya (Bear Island, Norway), elucidating the fate and the presence of persistent organic pollutants (POPs) in this pristine Arctic environment. High concentrations of POPs, like polychlorinated biphenyls (PCBs), dichloro-diphenyl-dichlorethane (DDE) and polybrominated diphenyl ethers (PBDEs) have been measured in sediment and biota from Ellasjoeen, a lake located in the southern, mountainous part of Bjoernoeya. In Lake Oeyangen, located only 6 km north of Ellasjoeen on the central plains of the island, levels of POPs are several times lower than in Ellasjoeen. One reason for the different POP contamination levels in Ellasjoeen and Oeyangen is probably differences in precipitation regime between the southern mountainous part of the island and the central plains further north, leading to differences in the deposition of air transported contaminants. Another possible source for contaminants to Ellasjoeen is the large colonies of seabirds (mainly kittiwake (Rissa tridactyla), little auk (Alle alle) and glaucous gull (Larus hyperboreus)), which are situated close to the lake during the ice-free period (early June - October). These seabirds feed in the marine environment, and deposit large amounts of guano (excrements) directly into the lake or in the catchment area of the lake. Oeyangen is not influenced by seabirds. There are two ways in which input from seabirds can lead to higher levels of POPs in Ellasjoeen: direct input of POPs through allochthonous material (guano, bird remains) a change in trophic state of the lake as a result of nutrient loadings from the seabirds. The aim of the present study was to investigate the role of guano as a transport medium for POPs to Ellasjoeen. Two main approaches were followed: an investigation of the trophic status of Ellasjoeen, as well as the reference lake, Oeyangen, through analyses of stable isotopes of carbon and nitrogen, analyses of selected

  10. Description and proposed life cycle of Maritrema novaezealandensis n. sp. (Microphallidae) parasitic in red-billed gulls, Larus novaehollandiae scopulinus, from Otago Harbor, South Island, New Zealand.

    Science.gov (United States)

    Martorelli, Sergio R; Fredensborg, Brian L; Mouritsen, Kim N; Poulin, Robert

    2004-04-01

    Maritrema novaezealandensis n. sp. is described from Otago Harbor, South Island, New Zealand, on the basis of adult specimens collected from the Red-billed gull, Larus novaehollandiae scopulinus, and excysted metacercariae obtained from crabs. It belongs to the "eroliae group" and differs from other related species mainly in the shape, size, and patterns of distributions of the spines on the cirrus, the shape of the metraterm, the presence of an unlobed ovary, and the complete ring of the vitelline follicles. Based on morphometric features of metacercariae and adult specimens, the trophic relationships among invertebrate and vertebrate hosts, experimental infections, and previous reports of species of Maritrema with similar transmission patterns, the life cycle of M. novaezealandensis n. sp. is described. A 3-host life cycle is proposed for this parasite. The first intermediate host is the mud snail, Zeacumantus subcarinatus, in which the cercarial stage is produced in sporocysts located within the gonad of the snail. At least 3 crab species (Hemigrapsus crenulatus, Macrophtalmus hirtipes, and Halicarcinus whitei) and several species of amphipods act as second intermediate hosts, with metacercariae encysted in the body cavity of the crustacean host. Finally, the definitive host, the gull, L. n. scopulinus, harbors the adult worms in its intestine.

  11. Polychlorinated camphenes (toxaphenes), polybrominated diphenylethers and other halogenated organic pollutants in glaucous gull (Larus hyperboreus) from Svalbard and Bjoernoeya (Bear Island)

    International Nuclear Information System (INIS)

    Herzke, Dorte; Gabrielsen, G.W.; Evenset, Anita; Burkow, I.C.

    2003-01-01

    PCBs and p,p'-DDE constituted 90% of contaminants found. - The levels of polychlorinated camphenes (toxaphenes) were investigated in liver samples from 18 glaucous gulls (Larus hyperboreus) from Bjoernoeya (74 deg. N, 19 deg. E) and four individuals from Longyearbyen (78 deg. N, 15 deg. E). Additionally brominated flame retardants (BFRs), PCBs and chlorinated pesticides were investigated in liver and intestinal contents of 15 of the glaucous gulls from Bjoernoeya. Of the analysed BFRs only 2,2',4,4'-tetra- and 2,2',4,4',5-pentabrominated diphenylethers (PBDE 47 and 99) could be detected. The concentrations ranged between 2 and 25 ng/g ww. In addition, high resolution measurements with GC/HRMS revealed the existence of several, not quantified, PBDEs and polybrominated biphenyls (PBBs) congeners in the samples. B9-1679 and B8-1413 were the dominating toxaphenes with median concentrations of 8 and 15 ng/g ww. Concentrations of toxaphenes and PBDEs were up to 100-times lower than the concentrations of PCB and some of the pesticides. PCB and p,p'-DDE constituted 90% of the contaminants found

  12. Nitrogen isotopic patterns of vegetation as affected by breeding activity of Black-tailed Gull (Larus crassiostris): A coupled analysis of feces, inorganic soil nitrogen and flora

    International Nuclear Information System (INIS)

    Mizota, C.

    2009-01-01

    Two currently breeding colonies (Matsushima Bay and Rishiri island; northern Japan) of predominant Black-tailed Gull (Larus crassiostris) were studied for N isotopic patterns of flora, which is affected by increased supply of inorganic soil N derived from the microbial transformation of feces. Coupled samples of feces, topsoil and flora were collected in early to mid July (2008), when input of fecal N onto soils was at its maximum. As bird migration and breeding continued, native Japanese red-pine (Pinus densiflora), junipers (Juniperus chinensis and Juniperus rigita; Matsushima Bay colony) and Sasa senanensis (Rishiri colony) declined, while ornithocoprophilus exotic plants succeeded. Among tree species on the islands, P. densiflora with ectomycorrizal colonization appears highly susceptible to elevated concentrations of NH 4 -N in the topsoil. A mechanism for best explaining the plant succession associated with the breeding activity of Black-tailed Gull was evidenced by two parameters: first, concomitant elevation of N content in the flora and second, inorganic soil N content, along with changes in N isotopic composition (δ 15 N). Earlier isotopic data on the foliar N affected by breeding activity were compiled and reviewed. Emphasis was put on isotopic information for inorganic N in soils that controls plant succession.

  13. Western Alaska ESI: LAKES (Lake Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing lakes and land masses used in the creation of the Environmental Sensitivity Index (ESI) for Western Alaska. The...

  14. Pollution at Lake Mariut

    International Nuclear Information System (INIS)

    Nour ElDin, H.; Halim, S. N.; Shalby, E.

    2004-01-01

    Lake Mariut, south Alexandria, Egypt suffered in the recent decades from intensive pollution as a result of a continuous discharge of huge amounts of agriculture wastewater that contains a large concentration of the washed pesticides and fertilizers in addition to domestic and industrial untreated wastewater. The over flow from the lake is discharged directly to the sea through El-Max pumping station via EI-Umum drain. Lake Mariout is surrounded by a huge number of different industrial activities and also the desert road is cutting the lake, this means that a huge number of various pollutants cycle through the air and settle down in the lake, by the time and during different seasons these pollutants after accumulation and different chemical interactions will release again from the lake to the surrounding area affecting the surrounding zone

  15. Release of infectious cells from epidermal ulcers in Ichthyophonus sp.-infected Pacific herring (Clupea pallasii): evidence for multiple mechanisms of transmission.

    Science.gov (United States)

    Kocan, Richard M; Gregg, Jacob L; Hershberger, Paul K

    2010-04-01

    A common clinical sign of ichthyophoniasis in herring and trout is "sandpaper" skin, a roughening of the epidermis characterized by the appearance of small papules, followed by ulceration and sloughing of the epithelium; early investigators hypothesized that these ulcers might be a means of transmitting the parasite, Ichthyophonus sp., without the necessity of ingesting an infected host. We examined the cells associated with the epidermal lesions and confirmed that they were viable Ichthyophonus sp. cells that were readily released from the skin into the mucous layer and ultimately into the aquatic environment. The released cells were infectious when injected into the body cavity of specific-pathogen-free herring. Our hypothesis is that different mechanisms of transmission occur in carnivorous and planktivorous hosts: Planktonic feeders become infected by ingestion of ulcer-derived cells, while carnivores become infected by ingestion of whole infected fish.

  16. Release of infectious cells from epidermal ulcers in Ichthyophonus sp.–infected Pacific Herring (Clupea pallasii): Evidence for multiple mechanisms of transmission

    Science.gov (United States)

    Hershberger, Paul K.; Gregg, Jacob L.; Kocan, R.M.

    2010-01-01

    A common clinical sign of ichthyophoniasis in herring and trout is “sandpaper” skin, a roughening of the epidermis characterized by the appearance of small papules, followed by ulceration and sloughing of the epithelium; early investigators hypothesized that these ulcers might be a means of transmitting the parasite, Ichthyophonus sp., without the necessity of ingesting an infected host. We examined the cells associated with the epidermal lesions and confirmed that they were viable Ichthyophonus sp. cells that were readily released from the skin into the mucous layer and ultimately into the aquatic environment. The released cells were infectious when injected into the body cavity of specific-pathogen-free herring. Our hypothesis is that different mechanisms of transmission occur in carnivorous and planktivorous hosts: Planktonic feeders become infected by ingestion of ulcer-derived cells, while carnivores become infected by ingestion of whole infected fish.

  17. Sublethal effects of the Exxon Valdez oil spill on herring embryos and larvae: morphological, cytogenetic; and histopathological assessments, 1989-1991

    International Nuclear Information System (INIS)

    Hose, J. E.; Marty, G. D.; Hinton, D. E.

    1996-01-01

    Extensive sublethal damage assessments were carried out on Pacific herring larvae following the Exxon Valdez oil spill. Egg masses were collected from oiled and non-oiled areas during 1989 to 1991, and incubated to hatch. The hatched larvae were evaluated for morphological deformities, cytogenetic abnormalities, and histopathological lesions. In 1989, herring larvae from the oiled areas showed high incidence of morphological deformities and cytogenetic abnormalities compared to larvae from non-oiled areas. There was no evidence of histopathological lesions. Identical assessments in 1990 and 1991 revealed no detectable oil-related developmental and genetic effects. In contrast, there was a marked decrease in survival, suggesting that that genetic damage at heavily oiled stations combined with severe morphological malformations mitigated against survival through the stressful larval period. 40 refs., 1 tab.,8 figs

  18. Distribution, density and abundance of the western Baltic herring ( Clupea harengus ) in the Sound (ICES Subdivision 23) in relation to hydrographical features

    DEFF Research Database (Denmark)

    Nielsen, J. Rasmus; Lundgren, Bo; Jensen, T. F.

    2001-01-01

    Biomass and duration of the over-wintering period of the Rugen spring spawning herring stock (RHS) in the Sound (ICES Subdivison 23) were investigated as well as possible hydrographical factors affecting relative distribution and triggering southwards migration towards the spawning grounds. Monit....... Monitoring was performed during 27 surveys over a 6-year period (1993-1998). Abundance of 45-165 000 t in August-February, 560 000 t in March-May, and...

  19. Developing Baltic cod recruitment models I : Resolving spatial and temporal dynamics of spawning stock and recruitment for cod, herring, and sprat

    DEFF Research Database (Denmark)

    Köster, Fritz; Möllmann, C.; Neuenfeldt, Stefan

    2001-01-01

    The Baltic Sea comprises a heterogeneous oceanographic environment influencing the spatial and temporal potential for reproductive success of cod (Gadus morhua) and sprat (Sprattus sprattus) in the different spawning basins. Hence, to quantify stock and recruitment dynamics, it is necessary......-disaggregated multispecies virtual population analyses (MSVPA) were performed for interacting species cod, herring (Clupea harengus), and sprat in the different subdivisions of the Central Baltic. The MSVPA runs revealed distinct spatial trends in population abundance, spawning biomass, recruitment, and predation...

  20. Great Lakes Literacy Principles

    Science.gov (United States)

    Fortner, Rosanne W.; Manzo, Lyndsey

    2011-03-01

    Lakes Superior, Huron, Michigan, Ontario, and Erie together form North America's Great Lakes, a region that contains 20% of the world's fresh surface water and is home to roughly one quarter of the U.S. population (Figure 1). Supporting a $4 billion sport fishing industry, plus $16 billion annually in boating, 1.5 million U.S. jobs, and $62 billion in annual wages directly, the Great Lakes form the backbone of a regional economy that is vital to the United States as a whole (see http://www.miseagrant.umich.edu/downloads/economy/11-708-Great-Lakes-Jobs.pdf). Yet the grandeur and importance of this freshwater resource are little understood, not only by people in the rest of the country but also by many in the region itself. To help address this lack of knowledge, the Centers for Ocean Sciences Education Excellence (COSEE) Great Lakes, supported by the U.S. National Science Foundation and the National Oceanic and Atmospheric Administration, developed literacy principles for the Great Lakes to serve as a guide for education of students and the public. These “Great Lakes Literacy Principles” represent an understanding of the Great Lakes' influences on society and society's influences on the Great Lakes.

  1. The Key Lake project

    International Nuclear Information System (INIS)

    1991-01-01

    Key Lake is located in the Athabasca sand stone basin, 640 kilometers north of Saskatoon, Saskatchewan, Canada. The three sources of ore at Key Lake contain 70 100 tonnes of uranium. Features of the Key Lake Project were described under the key headings: work force, mining, mill process, tailings storage, permanent camp, environmental features, worker health and safety, and economic benefits. Appendices covering the historical background, construction projects, comparisons of western world mines, mining statistics, Northern Saskatchewan surface lease, and Key Lake development and regulatory agencies were included

  2. Inability to demonstrate fish-to-fish transmission of Ichthyophonus from laboratory infected Pacific herring Clupea pallasii to naïve conspecifics.

    Science.gov (United States)

    Gregg, J L; Grady, C A; Friedman, C S; Hershberger, P K

    2012-06-13

    The parasite Ichthyophonus is enzootic in many marine fish populations of the northern Atlantic and Pacific Oceans. Forage fishes are a likely source of infection for higher trophic level predators; however, the processes that maintain Ichthyophonus in forage fish populations (primarily clupeids) are not well understood. Lack of an identified intermediate host has led to the convenient hypothesis that the parasite can be maintained within populations of schooling fishes by waterborne fish-to-fish transmission. To test this hypothesis we established Ichthyophonus infections in Age-1 and young-of-the-year (YOY) Pacific herring Clupea pallasii (Valenciennes) via intraperitoneal (IP) injection and cohabitated these donors with naïve conspecifics (sentinels) in the laboratory. IP injections established infection in 75 to 84% of donor herring, and this exposure led to clinical disease and mortality in the YOY cohort. However, after cohabitation for 113 d no infections were detected in naïve sentinels. These data do not preclude the possibility of fish-to-fish transmission, but they do suggest that other transmission processes are necessary to maintain Ichthyophonus in wild Pacific herring populations.

  3. Limnology of Eifel maar lakes

    National Research Council Canada - National Science Library

    Scharf, Burkhard W; Björk, Sven

    1992-01-01

    ... : Species composition & seasonal periodicity - Qualitative & quantitative investigations on cladoceran zooplankton of oligotrophic maar lakes - Population dynamics of pelagic copepods in maar lakes - Population dynamics...

  4. Comparison of three nonlinear models to describe long-term tag shedding by lake trout

    Science.gov (United States)

    Fabrizio, Mary C.; Swanson, Bruce L.; Schram, Stephen T.; Hoff, Michael H.

    1996-01-01

    We estimated long-term tag-shedding rates for lake trout Salvelinus namaycush using two existing models and a model we developed to account for the observed permanence of some tags. Because tag design changed over the course of the study, we examined tag-shedding rates for three types of numbered anchor tags (Floy tags FD-67, FD-67C, and FD-68BC) and an unprinted anchor tag (FD-67F). Lake trout from the Gull Island Shoal region, Lake Superior, were double-tagged, and subsequent recaptures were monitored in annual surveys conducted from 1974 to 1992. We modeled tag-shedding rates, using time at liberty and probabilities of tag shedding estimated from fish released in 1974 and 1978–1983 and later recaptured. Long-term shedding of numbered anchor tags in lake trout was best described by a nonlinear model with two parameters: an instantaneous tag-shedding rate and a constant representing the proportion of tags that were never shed. Although our estimates of annual shedding rates varied with tag type (0.300 for FD-67, 0.441 for FD-67C, and 0.656 for FD-68BC), differences were not significant. About 36% of tags remained permanently affixed to the fish. Of the numbered tags that were shed (about 64%), two mechanisms contributed to tag loss: disintegration and dislodgment. Tags from about 11% of recaptured fish had disintegrated, but most tags were dislodged. Unprinted tags were shed at a significant but low rate immediately after release, but the long-term, annual shedding rate of these tags was only 0.013. Compared with unprinted tags, numbered tags dislodged at higher annual rates; we hypothesized that this was due to the greater frictional drag associated with the larger cross-sectional area of numbered tags.

  5. Lakes, Lagerstaetten, and Evolution

    Science.gov (United States)

    Kordesch, E. G.; Park, L. E.

    2001-12-01

    The diversity of terrestrial systems is estimated to be greater than in the marine realm. However no hard data yet exists to substantiate this claim. Ancient lacustrine deposits may preserve an exceptionally diverse fossil fauna and aid in determining continental faunal diversities. Fossils preserved in lake deposits, especially those with exceptional preservation (i.e. Konservat Lagerstaetten), may represent a dependable method for determining species diversity changes in the terrestrial environment because of their faunal completeness. Important Konservat Lagerstaetten, such as the Green River Formation (US) and Messel (Germany), both Eocene in age, are found in lake sediments and show a remarkable faunal diversity for both vertebrates and invertebrates. To date information from nearly 25 lake lagerstaetten derived from different types of lake basins from the Carboniferous to the Miocene have been collected and described. Carboniferous sites derive from the cyclothems of Midcontinent of the US while many Cenozoic sites have been described from North and South America as well as Europe and Australia. Asian sites contain fossils from the Mesozoic and Cenozoic. With this data, insight into the evolutionary processes associated with lake systems can be examined. Do lakes act as unique evolutionary crucibles in contrast to marine systems? The speciation of cichlid fishes in present-day African lakes appears to be very high and is attributed to the diversity of environments found in large rift lakes. Is this true of all ancient lakes or just large rift lakes? The longevity of a lake system may be an important factor in allowing speciation and evolutionary processes to occur; marine systems are limited only in the existence of environments as controlled by tectonics and sea level changes, on the order of tens of millions of years. Rift lakes are normally the longest lived in the millions of years. Perhaps there are only certain types of lakes in which speciation of

  6. Trophodynamics of inorganic pollutants in a wide-range feeder: The relevance of dietary inputs and biomagnification in the Yellow-legged gull (Larus michahellis)

    International Nuclear Information System (INIS)

    Ramos, Raül; Ramírez, Francisco; Jover, Lluís

    2013-01-01

    The suitability of sentinel species to monitor environmental pollution is often hampered by an insufficient knowledge on pollutant trophodynamics. We simultaneously evaluated the influence of individuals' trophic position (as revealed by δ 15 N values) and dietary exploitation of particular systems (using δ 13 C and δ 34 S as proxies) on inorganic pollutant concentrations measured on fledglings' feathers of a wide-range feeder, the Yellow-legged Gull (Larus michahellis), sampled at four locations throughout the Western Mediterranean. Concentrations of total Hg and Se in fledgling feathers (2.43 ± 1.30 and 1.16 ± 0.43 μg/g, respectively) were under the threshold points for deleterious effects on seabirds. On the contrary, alarming Pb concentrations were found in one colony (mean: 1.57 ± 2.46 μg/g, range: 0.16–12.13). With the exception of Pb, pollutant concentrations were positively influenced by consumption of marine resources (as suggested by the positive relationship with δ 34 S values), whereas trophic position played a minor role in determining pollutant body burdens. - Graphical abstract: Individual feeding behaviours in wide-range feeders may represent unavoidable knowledge for an appropriate understanding of contaminant acquisition, adding complexity to the study of the dynamic of contaminants throughout food chains. In this case study, pollutant body burden of Yellow-legged gull (Larus michahellis) chicks was highly influenced by dietary exposure, whereas the influence of trophic position was relatively low. Display Omitted Highlights: ► Diet origin (δ 34 S) and trophic position (δ 15 N) were tested relative to Hg, Se, and Pb levels. ► Hg and Se concentrations in gull feathers were highly influenced by δ 34 S signatures. ► Exploited habitat influenced pollutant levels to a greater extent than trophic position. ► Biomagnification processes contribute less to contamination exposure in wide-range feeders. - Pollutant body burden of a wide

  7. Ecology of Meromictic Lakes

    NARCIS (Netherlands)

    Gulati, R.D.; Zadereev, E.S.; Degermendzhy, A.G.

    2017-01-01

    This volume presents recent advances in the research on meromictic lakes and a state-of-the art overview of this area. After an introduction to the terminology and geographic distribution of meromictic lakes, three concise chapters describe their physical, chemical and biological features. The

  8. Lake Afdera: a threatened saline lake in Ethiopia | Getahun | SINET ...

    African Journals Online (AJOL)

    Lake Afdera is a saline lake located in the Afar region, Northern Ethiopia. Because of its inaccessibility it is one of the least studied lakes of the country. It supports life including three species of fish of which two are endemic. Recently, reports are coming out that this lake is used for salt extraction. This paper gives some ...

  9. Lake trout in northern Lake Huron spawn on submerged drumlins

    Science.gov (United States)

    Riley, Stephen C.; Binder, Thomas; Wattrus, Nigel J.; Faust, Matthew D.; Janssen, John; Menzies, John; Marsden, J. Ellen; Ebener, Mark P.; Bronte, Charles R.; He, Ji X.; Tucker, Taaja R.; Hansen, Michael J.; Thompson, Henry T.; Muir, Andrew M.; Krueger, Charles C.

    2014-01-01

    Recent observations of spawning lake trout Salvelinus namaycush near Drummond Island in northern Lake Huron indicate that lake trout use drumlins, landforms created in subglacial environments by the action of ice sheets, as a primary spawning habitat. From these observations, we generated a hypothesis that may in part explain locations chosen by lake trout for spawning. Most salmonines spawn in streams where they rely on streamflows to sort and clean sediments to create good spawning habitat. Flows sufficient to sort larger sediment sizes are generally lacking in lakes, but some glacial bedforms contain large pockets of sorted sediments that can provide the interstitial spaces necessary for lake trout egg incubation, particularly if these bedforms are situated such that lake currents can penetrate these sediments. We hypothesize that sediment inclusions from glacial scavenging and sediment sorting that occurred during the creation of bedforms such as drumlins, end moraines, and eskers create suitable conditions for lake trout egg incubation, particularly where these bedforms interact with lake currents to remove fine sediments. Further, these bedforms may provide high-quality lake trout spawning habitat at many locations in the Great Lakes and may be especially important along the southern edge of the range of the species. A better understanding of the role of glacially-derived bedforms in the creation of lake trout spawning habitat may help develop powerful predictors of lake trout spawning locations, provide insight into the evolution of unique spawning behaviors by lake trout, and aid in lake trout restoration in the Great Lakes.

  10. Interaction Mode between Inclusion Complex of Vitamin K3 with γ- Cyclodextrin and Herring-Sperm DNA.

    Science.gov (United States)

    Tang, Yan; Cai, Li; Xue, Kang; Wang, Chunling; Xiong, Xiaoli

    2016-05-03

    Methods including spectroscopy, electronic chemistry and thermodynamics were used to study the inclusion effect between γ-cyclodextrin (CD) and vitamin K3(K3), as well as the interaction mode between herring-sperm DNA (hsDNA) and γ-CD-K3 inclusion complex. The results from ultraviolet spectroscopic method indicated that VK3 and γ-CD formed 1:1 inclusion complex, with the inclusion constant Kf = 1.02 × 10(4) L/mol, which is based on Benesi-Hildebrand's viewpoint. The outcomes from the probe method and Scatchard methods suggested that the interaction mode between γ-CD-K3 and DNA was a mixture mode, which included intercalation and electrostatic binding effects. The binding constants were K (θ)25°C = 2.16 × 10(4) L/mol, and K(θ)37°C = 1.06 × 10(4) L/mol. The thermodynamic functions of the interaction between γ-CD-K3 and DNA were ΔrHm(θ) = -2.74 × 10(4) J/mol, ΔrSm(θ) = 174.74 J·mol(-1)K(-1), therefore, both ΔrHm(θ) (enthalpy) and ΔrSm(θ) (entropy) worked as driven forces in this action.

  11. Length correction for early-juvenile Brazilian herring Sardinella janeiro (Eigenmann, 1894 after preservation in formalin, ethanol and freezing

    Directory of Open Access Journals (Sweden)

    Joaquim N. S. Santos

    Full Text Available This work aims to quantify the variation in total length and body mass for the early-juvenile Brazilian herring Sardinella janeiro and to determine total length and body mass correction equation to allow fresh measures to be calculated from preserved ones. Fishes were randomly assigned to one of five preservation methods (freezing at - 20º C, 2.5% and 5% formalin, 70% and 95% ethanol, and measured for total length (TL and body mass (W before preservation, and on days 5, 15, 30, and 60 after storage. Significant reductions in total length and body mass occurred during the first 5 days after preservation and continued to contract significantly at a lesser rate through 30 days in most methods. Exceptions were shown for body mass in freezing and 5% formalin, where the greatest losses occurred after 30 days of preservation. The degree of shrinkage for total length and body mass was very much dependent on fish size, with smaller specimens shrinking more than larger ones. The fresh total length and body mass can be back-calculated using equations that describe the relationship between fresh and preserved individuals after 60 days storage for all methods except for body mass in freezing.

  12. Lake sturgeon population characteristics in Rainy Lake, Minnesota and Ontario

    Science.gov (United States)

    Adams, W.E.; Kallemeyn, L.W.; Willis, D.W.

    2006-01-01

    Rainy Lake contains a native population of lake sturgeon Acipenser fulvescens that has been largely unstudied. The aims of this study were to document the population characteristics of lake sturgeon in Rainy Lake and to relate environmental factors to year-class strength for this population. Gill-netting efforts throughout the study resulted in the capture of 322 lake sturgeon, including 50 recaptures. Lake sturgeon in Rainy Lake was relatively plump and fast growing compared with a 32-population summary. Population samples were dominated by lake sturgeon between 110 and 150 cm total length. Age–structure analysis of the samples indicated few younger (<10 years) lake sturgeon, but the smallest gill net mesh size used for sampling was 102 mm (bar measure) and would not retain small sturgeon. Few lake sturgeon older than age 50 years were captured, and maximum age of sampled fish was 59 years. Few correlations existed between lake sturgeon year-class indices and both annual and monthly climate variables, except that mean June air temperature was positively correlated with year-class strength. Analysis of Rainy Lake water elevation and resulting lake sturgeon year-class strength indices across years yielded consistent but weak negative correlations between late April and early June, when spawning of lake sturgeon occurs. The baseline data collected in this study should allow Rainy Lake biologists to establish more specific research questions in the future.

  13. Yellowstone Lake Nanoarchaeota

    Directory of Open Access Journals (Sweden)

    Scott eClingenpeel

    2013-09-01

    Full Text Available Considerable Nanoarchaeota novelty and diversity were encountered in Yellowstone Lake, Yellowstone National Park, where sampling targeted lake floor hydrothermal vent fluids, streamers and sediments associated with these vents, and in planktonic photic zones in three different regions of the lake. Significant homonucleotide repeats (HR were observed in pyrosequence reads and in near full-length Sanger sequences, averaging 112 HR per 1,349 bp clone and could confound diversity estimates derived from pyrosequencing, resulting in false nucleotide insertions or deletions (indels. However, Sanger sequencing of two different sets of PCR clones (110 bp, 1349 bp demonstrated that at least some of these indels are real. The majority of the Nanoarchaeota PCR amplicons were vent associated; however, curiously, one relatively small Nanoarchaeota OTU (70 pyrosequencing reads was only found in photic zone water samples obtained from a region of the lake furthest removed from the hydrothermal regions of the lake. Extensive pyrosequencing failed to demonstrate the presence of an Ignicoccus lineage in this lake, suggesting the Nanoarchaeota in this environment are associated with novel Archaea hosts. Defined phylogroups based on near full-length PCR clones document the significant Nanoarchaeota 16S rRNA gene diversity in this lake and firmly establish a terrestrial clade distinct from the marine Nanoarcheota as well as from other geographical locations.

  14. Whiting in Lake Michigan

    Science.gov (United States)

    2002-01-01

    Satellites provide a view from space of changes on the Earth's surface. This series of images from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) aboard the Orbview-2 satellite shows the dramatic change in the color of Lake Michigan during the summer. The bright color that appears in late summer is probably caused by calcium carbonate-chalk-in the water. Lake Michigan always has a lot of calcium carbonate in it because the floor of the lake is limestone. During most of the year the calcium carbonate remains dissolved in the cold water, but at the end of summer the lake warms up, lowering the solubility of calcium carbonate. As a result, the calcium carbonate precipitates out of the water, forming clouds of very small solid particles that appear as bright swirls from above. The phenomenon is appropriately called a whiting event. A similar event occured in 1999, but appears to have started later and subsided earlier. It is also possible that a bloom of the algae Microcystis is responsible for the color change, but unlikely because of Lake Michigan's depth and size. Microcystis blooms have occured in other lakes in the region, however. On the shore of the lake it is possible to see the cities of Chicago, Illinois, and Milwaukee, Wisconsin. Both appear as clusters of gray-brown pixels. Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  15. Ecology of playa lakes

    Science.gov (United States)

    Haukos, David A.; Smith, Loren M.

    1992-01-01

    Between 25,000 and 30,000 playa lakes are in the playa lakes region of the southern high plains (Fig. 1). Most playas are in west Texas (about 20,000), and fewer, in New Mexico, Oklahoma, Kansas, and Colorado. The playa lakes region is one of the most intensively cultivated areas of North America. Dominant crops range from cotton in southern areas to cereal grains in the north. Therefore, most of the native short-grass prairie is gone, replaced by crops and, recently, grasses of the Conservation Reserve Program. Playas are the predominant wetlands and major wildlife habitat of the region.More than 115 bird species, including 20 species of waterfowl, and 10 mammal species have been documented in playas. Waterfowl nest in the area, producing up to 250,000 ducklings in wetter years. Dominant breeding and nesting species are mallards and blue-winged teals. During the very protracted breeding season, birds hatch from April through August. Several million shorebirds and waterfowl migrate through the area each spring and fall. More than 400,000 sandhill cranes migrate through and winter in the region, concentrating primarily on the larger saline lakes in the southern portion of the playa lakes region.The primary importance of the playa lakes region to waterfowl is as a wintering area. Wintering waterfowl populations in the playa lakes region range from 1 to 3 million birds, depending on fall precipitation patterns that determine the number of flooded playas. The most common wintering ducks are mallards, northern pintails, green-winged teals, and American wigeons. About 500,000 Canada geese and 100,000 lesser snow geese winter in the playa lakes region, and numbers of geese have increased annually since the early 1980’s. This chapter describes the physiography and ecology of playa lakes and their attributes that benefit waterfowl.

  16. Halls Lake 1990

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Salt marsh habitats along the shoreline of Halls Lake are threatened by wave erosion, but the reconstruction of barrier islands to reduce this erosion will modify or...

  17. Lake Level Reconstructions

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past lake levels, mostly related to changes in moisture balance (evaporation-precipitation). Parameter keywords describe what was measured in this data...

  18. The Key Lake project

    International Nuclear Information System (INIS)

    Glattes, G.

    1985-01-01

    Aspects of project financing for the share of the Canadian subsidiary of Uranerzbergbau-GmbH, Bonn, in the uranium mining and milling facility at Key Lake, Saskatchewan, by a Canadian bank syndicate. (orig.) [de

  19. Great Lakes Ice Charts

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Charts show ice extent and concentration three times weekly during the ice season, for all lakes except Ontario, from the 1973/74 ice season through the 2001/2002...

  20. Foy Lake paleodiatom data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Percent abundance of 109 diatom species collected from a Foy Lake (Montana, USA) sediment core that was sampled every ∼5–20 years, yielding a ∼7 kyr record over 800...

  1. Dragon Lake, Siberia

    Science.gov (United States)

    2002-01-01

    Nicknamed 'Dragon Lake,' this body of water is formed by the Bratskove Reservoir, built along the Angara river in southern Siberia, near the city of Bratsk. This image was acquired in winter, when the lake is frozen. This image was acquired by Landsat 7's Enhanced Thematic Mapper plus (ETM+) sensor on December 19, 1999. This is a natural color composite image made using blue, green, and red wavelengths. Image provided by the USGS EROS Data Center Satellite Systems Branch

  2. Influência da temperatura na reprodução e longevidade do predador Orius thyestes Herring (Hemiptera, Anthocoridae Influence of the temperature on reproduction and longevity of the predator Orius thyestes Herring (Hemiptera, Anthocoridae

    Directory of Open Access Journals (Sweden)

    Lívia Mendes Carvalho

    2005-09-01

    Full Text Available O desenvolvimento e a fecundidade das espécies de Orius são bastante influenciados por uma série de fatores, como as condições ambientais, e em particular, pela temperatura. Esse trabalho teve como objetivo avaliar a reprodução e a longevidade de Orius thyestes Herring 1966 em diferentes temperaturas, tendo como alimento, ovos de Anagasta kuehniella (Zeller, 1879. O experimento foi conduzido em câmaras climatizadas com temperaturas de 16, 19, 22, 25, 28, 31 ± 1ºC, UR de 70±10% e fotofase de 12horas. Efeito deletério da temperatura em O. thyestes foi obtido a 16ºC, na qual apenas 40% das ninfas atingiram a fase adulta, e destes apenas 19% não apresentaram deformações morfológicas. O maior período de pré-oviposição foi observado a 19ºC (17,8 dias. Os maiores valores para a fecundidade média total foram registrados a 25 e 28ºC, com 109,2 e 128,2 ovos/fêmea, respectivamente, e o menor a 19ºC, com 22,8 ovos/fêmea. A 22 e 31ºC as fêmeas viveram mais que os machos, sendo que a 19ºC a longevidade foi maior, independente do sexo. As baixas temperaturas influenciaram a reprodução e longevidade de O. thyestes sugerindo que esta espécie poderá ter melhor performance reprodutiva em temperaturas mais elevadas, como aquelas de regiões tropicais e ou subtropicais.The development time and the fecundity of Orius species are strongly influenced by a wide range of factors, like environmental conditions and in particular temperature. This work aimed to evaluate the reproduction and adult longevity of Orius thyestes Herring, 1966 in different temperatures. Eggs of Anagasta kuehniella (Zeller, 1879 was provide as food supply. The experiment was carried out in climatic chambers at temperatures 16, 19, 22, 25, 28 and 31 ± 1°C, RH 70 ±10% and photophase 12h. A deleterious effect of the temperature on O. thyestes was found at 16°C, in which only 40% of the nymphs reached adulthood, of which only 19% presented normal morphological

  3. Lake Chad, Chad, Africa

    Science.gov (United States)

    1992-01-01

    Hydrologic and ecologic changes in the Lake Chad Basin are shown in this Oct 1992 photograph. In space photo documentation, Lake Chad was at its greatest area extent (25,000 sq. km.) during Gemini 9 in June 1966 (see S66-38444). Its reduction during the severe droughts from 1968 to 1974 was first noted during Skylab (1973-1974). After the drought began again in 1982, the lake reached its minimum extent (1,450 sq. km.) in Space Shuttle photographs taken in 1984 and 1985. In this STS-52 photograph, Lake Chad has begun to recover. The area of the open water and interdunal impoundments in the southern basin (the Chari River Basin) is estimated to be 1,900 to 2100 sq. km. Note the green vegetation in the valley of the K'Yobe flow has wetted the northern lake basin for the first time in several years. There is evidence of biomass burning south of the K'Yobe Delta and in the vegetated interdunal areas near the dike in the center of the lake. Also note the dark 'Green Line' of the Sahel (the g

  4. Avian botulism type E in waterbirds of Lake Michigan, 2010–2013

    Science.gov (United States)

    Chipault, Jennifer G.; White, C. LeAnn; Blehert, David S.; Jennings, Susan K.; Strom, Sean M.

    2015-01-01

    During 2010 to 2013, waterbird mortality surveillance programs used a shared protocol for shoreline walking surveys performed June to November at three areas in northern Lake Michigan. In 2010 and 2012, 1244 total carcasses (0.8 dead bird/km walked) and 2399 total carcasses (1.2 dead birds/km walked), respectively, were detected. Fewer carcasses were detected in 2011 (353 total carcasses, 0.2 dead bird/km walked) and 2013 (451 total carcasses, 0.3 dead bird/km walked). During 3 years, peak detection of carcasses occurred in October and involved primarily migratory diving and fish-eating birds, including long-tailed ducks (Clangula hyemalis; 2010), common loons (Gavia immer; 2012), and red-breasted mergansers (Mergus serrator; 2013). In 2011, peak detection of carcasses occurred in August and consisted primarily of summer residents such as gulls (Larus spp.) and double-crested cormorants (Phalacrocorax auritus). A subset of fresh carcasses was collected throughout each year of the study and tested for botulinum neurotoxin type E (BoNT/E). Sixty-one percent of carcasses (57/94) and 10 of 11 species collected throughout the sampling season tested positive for BoNT/E, suggesting avian botulism type E was a major cause of death for both resident and migratory birds in Lake Michigan. The variety of avian species affected by botulism type E throughout the summer and fall during all 4 years of coordinated surveillance also suggests multiple routes for bird exposure to BoNT/E in Lake Michigan.

  5. Resilience and Restoration of Lakes

    Directory of Open Access Journals (Sweden)

    Stephen R. Carpenter

    1997-06-01

    Full Text Available Lake water quality and ecosystem services are normally maintained by several feedbacks. Among these are nutrient retention and humic production by wetlands, nutrient retention and woody habitat production by riparian forests, food web structures that cha nnel phosphorus to consumers rather than phytoplankton, and biogeochemical mechanisms that inhibit phosphorus recycling from sediments. In degraded lakes, these resilience mechanisms are replaced by new ones that connect lakes to larger, regional economi c and social systems. New controls that maintain degraded lakes include runoff from agricultural and urban areas, absence of wetlands and riparian forests, and changes in lake food webs and biogeochemistry that channel phosphorus to blooms of nuisance al gae. Economic analyses show that degraded lakes are significantly less valuable than normal lakes. Because of this difference in value, the economic benefits of restoring lakes could be used to create incentives for lake restoration.

  6. Is Lake Chabot Eutrophic?

    Science.gov (United States)

    Pellegrini, K.; Logan, J.; Esterlis, P.; Lew, A.; Nguyen, M.

    2013-12-01

    Introduction/Abstract: Lake Chabot is an integral part of the East Bay watershed that provides habitats for animals and recreation for humans year-round. Lake Chabot has been in danger of eutrophication due to excessive dumping of phosphorous and nitrogen into the water from the fertilizers of nearby golf courses and neighboring houses. If the lake turned out to be eutrophified, it could seriously impact what is currently the standby emergency water supply for many Castro Valley residents. Eutrophication is the excessive richness of nutrients such as nitrogen and phosphorus in a lake, usually as a result of runoff. This buildup of nutrients causes algal blooms. The algae uses up most of the oxygen in the water, and when it dies, it causes the lake to hypoxify. The fish in the lake can't breathe, and consequently suffocate. Other oxygen-dependant aquatic creatures die off as well. Needless to say, the eutrophication of a lake is bad news for the wildlife that lives in or around it. The level of eutrophication in our area in Northern California tends to increase during the late spring/early summer months, so our crew went out and took samples of Lake Chabot on June 2. We focused on the area of the lake where the water enters, known on the map as Honker Bay. We also took readings a ways down in deeper water for comparison's sake. Visually, the lake looked in bad shape. The water was a murky green that glimmered with particulate matter that swirled around the boat as we went by. In the Honker Bay region where we focused our testing, there were reeds bathed in algae that coated the surface of the lake in thick, swirling patterns. Surprisingly enough, however, our test results didn't reveal any extreme levels of phosphorous or nitrogen. They were slightly higher than usual, but not by any significant amount. The levels we found were high enough to stimulate plant and algae growth and promote eutrophication, but not enough to do any severe damage. After a briefing with a

  7. Results of the radiological verification survey at the former Herring-Hall-Marvin Safe Company, 1550 Grand Boulevard, Hamilton Ohio (HO001V)

    International Nuclear Information System (INIS)

    Murray, M.E.; allred, J.F.; Johnson, C.A.

    1995-11-01

    During the period between the 1940s and early 1950s, the Herring-Hall-Marvin Safe Company, 1550 Grand Boulevard, Hamilton, Ohio, was one company under subcontract to the Manhattan Engineer District (MED), and the Atomic Energy Commission (AEC), the lead agencies in the development of nuclear energy for defense-related projects. The US Department of Energy (DOE) conducted radiological surveys of these sites to evaluate current radiological conditions as part of the Formerly Utilized Sites Remedial Action Program (FUSRAP). In 1988, a radiological survey of the Herring-Hall-Marvin Safe Company facility was conducted, and after small fragments of uranium metal were removed, no beta or gamma radiation above background was detected and the building was dismissed from any additional DOE restrictions. In 1993, it was discovered that a portion of the actual machining work was conducted on the third floor of the facility, located in the southeastern comer of the building. At the request of DOE, this part of the facility was radiologically surveyed by an ORNL survey team to determine whether fixed surface contamination could be found that might exceed the DOE guidelines. Results of this radiological survey indicated 238 U contamination in excess of the DOE criteria for surface contamination, and the site was recommended for remediation. In February and March of 1995, a verification survey of the third floor of the former Herring-Hall-Marvin Safe Company facility by an ORNL survey team was performed in conjunction with decontamination operations conducted under the supervision of Bechtel National Incorporated. The verification survey included gamma scans at the surface and at one meter, alpha and beta-gamma scans for fixed contamination, and smears for transferable contamination

  8. A field and laboratory assessment of oil spill effects on survival and reproduction of Pacific herring following the Exxon Valdez spill

    International Nuclear Information System (INIS)

    Pearson, W.H.; Moksness, E.

    1995-01-01

    Field and laboratory investigations in 1989 and 1990 were designed to assess potential injury to Prince William Sound herring by testing for differences between oiled regions and unoiled reference areas and by relating biological response variables to the concentrations of polycyclic aromatic hydrocarbons (PAH) in eggs-on-kelp samples. Hydrocarbon analyses and laboratory incubation were conducted on eggs-on-kelp samples from Prince William Sound and Sitka Sound. The eggs and hatching larvae were examined to evaluate several response variables: egg development, hatch, larval survival, abnormal development of larvae, larval length, and larval yolk-sac volume. Analysis of 1989 shoreline surveys indicate that about 96% of the total spawn length (158 km) in Prince William Sound occurred along shorelines with no oiling, and less than 1% of the 1989 total spawn length occurred along shorelines with moderate to heavy oiling. Analysis of shoreline oiling in both 1989 and 1990 from all surveys indicates that about 90 to 91% of the total 1989 spawn length occurred along unoiled shorelines. Effects on herring eggs were minor in 1989 even in oiled areas. No significant relationship was found between 1989 PAH burdens in eggs-on-kelp samples and 9 out of 10 biological response variables. In 1989, significantly lower proportions of developed eggs were observed for Cabin Bay samples visibly contaminated with tarry deposits. The location where these effects were seen represented less than 2% of total 1989 spawn length. No effects of the spill on herring were evident in 1990. No significant relationship was found between 1990 PAH burdens and the seven biological response variables studied. 33 refs., 11 figs., 5 tabs

  9. Viral hemorrhagic septicemia virus, Ichthyophonus hoferi, and other causes of morbidity in Pacific herring Clupea pallasi spawning in Prince William Sound, Alaska, USA.

    Science.gov (United States)

    Marty, G D; Freiberg, E F; Meyers, T R; Wilcock, J; Farver, T B; Hinton, D E

    1998-02-26

    Pacific herring Clupea pallasi populations in Prince William Sound, Alaska, USA, declined from an estimated 9.8 x 10(7) kg in 1992 to 1.5 x 10(7) kg in 1994. To determine the role of disease in population decline, 233 Pacific herring from Prince William Sound were subjected to complete necropsy during April 1994. The North American strain of viral hemorrhagic septicemia virus (VHSV) was isolated from 11 of 233 fish (4.7%). VHSV was significantly related to myocardial mineralization, hepatocellular necrosis, submucosal gastritis, and meningoencephalitis. Ichthyophonus hoferi infected 62 of 212 (29%) fish. I. hoferi infections were associated with severe, disseminated, granulomatous inflammation and with increased levels of plasma creatine phosphokinase (CPK) and aspartate aminotransferase (AST). I. hoferi prevalence in 1994 was more than double that of most previous years (1989 to 1993). Plasma chemistry values significantly greater (p < 0.01) in males than females included albumin, total protein, cholesterol, chloride, glucose, and potassium; only alkaline phosphatase was significantly greater in females. Hypoalbuminemia was relatively common in postspawning females; other risk factors included VHSV and moderate or severe focal skin reddening. Pacific herring had more than 10 species of parasites, but they were not associated with significant lesions. Two of the parasites have not previously been described: a renal intraductal myxosporean (11% prevalence) and an intestinal coccidian (91% prevalence). Transmission electron microscopy of a solitary mesenteric lesion revealed viral particles consistent with lymphocystis virus. No fish had viral erythrocytic necrosis (VEN). Prevalence of external gross lesions and major parasites was not related to fish age, and fish that were year-lings at the time of the 1989 'Exxon Valdez' oil spill (1988 year class) had no evidence of increased disease prevalence.

  10. Polychlorinated dibenzo-p-dioxins, dibenzofurans, biphenyls, naphthalenes and polybrominated diphenyl ethers in the edible fish caught from the Baltic Sea and lakes in Finland

    International Nuclear Information System (INIS)

    Isosaari, Pirjo; Hallikainen, Anja; Kiviranta, Hannu; Vuorinen, Pekka J.; Parmanne, Raimo; Koistinen, Jaana; Vartiainen, Terttu

    2006-01-01

    A total of 156 fish composite samples were collected from five areas of the Baltic Sea and from three lakes and analysed for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs) and polybrominated diphenyl ethers (PBDEs). The European Union's maximum permissible level for PCDD/Fs, 4 pg WHO-TEQ/g fresh weight (fw), was exceeded in salmon, river lamprey and Baltic herring. In other species from the Baltic Sea, the 90th percentile was 3.42 pg WHO PCDD/F -TEQ/g fw. In the lake fish, the concentrations of PCDD/Fs, PCBs and PCNs were only 29-46% of those in the same species caught from the Baltic Sea, whereas the concentrations of PBDEs in the lake fish were as high as in the Baltic Sea fish. Dioxin-like PCBs contributed to the total dioxin-like toxicity of PCBs and PCDD/Fs by 49 ± 12% in all the analysed samples. - Lake fish is less contaminated with dioxins, PCBs and chloronaphthalenes than Baltic Sea fish but similarly contaminated with polybrominated diphenyl ethers

  11. Human-Induced Long-Term Shifts in Gull Diet from Marine to Terrestrial Sources in North America's Coastal Pacific: More Evidence from More Isotopes (δ2H, δ34S).

    Science.gov (United States)

    Hobson, Keith A; Blight, Louise K; Arcese, Peter

    2015-09-15

    Measurements of naturally occurring stable isotopes in tissues of seabirds and their prey are a powerful tool for investigating long-term changes in marine foodwebs. Recent isotopic (δ(15)N, δ(13)C) evidence from feathers of Glaucous-winged Gulls (Larus glaucescens) has shown that over the last 150 years, this species shifted from a midtrophic marine diet to one including lower trophic marine prey and/or more terrestrial or freshwater foods. However, long-term isotopic patterns of δ(15)N and δ(13)C cannot distinguish between the relative importance of lower trophic-level marine foods and terrestrial sources. We examined 48 feather stable-hydrogen (δ(2)H) and -sulfur (δ(34)S) isotope values from this same 150-year feather set and found additional isotopic evidence supporting the hypothesis that gulls shifted to terrestrial and/or freshwater prey. Mean feather δ(2)H and δ(34)S values (± SD) declined from the earliest period (1860-1915; n = 12) from -2.5 ± 21.4 ‰ and 18.9 ± 2.7 ‰, respectively, to -35.5 ± 15.5 ‰ and 14.8 ± 2.4 ‰, respectively, for the period 1980-2009 (n = 12). We estimated a shift of ∼ 30% increase in dependence on terrestrial/freshwater sources. These results are consistent with the hypothesis that gulls increased terrestrial food inputs in response to declining forage fish availability.

  12. Testing of an oral dosing technique for double-crested cormorants, Phalacocorax auritus, laughing gulls, Leucophaeus atricilla, homing pigeons, Columba livia, and western sandpipers, Calidris mauri, with artificially weather MC252 oil.

    Science.gov (United States)

    Dean, K M; Cacela, D; Carney, M W; Cunningham, F L; Ellis, C; Gerson, A R; Guglielmo, C G; Hanson-Dorr, K C; Harr, K E; Healy, K A; Horak, K E; Isanhart, J P; Kennedy, L V; Link, J E; Lipton, I; McFadden, A K; Moye, J K; Perez, C R; Pritsos, C A; Pritsos, K L; Muthumalage, T; Shriner, S A; Bursian, S J

    2017-12-01

    Scoping studies were designed to determine if double-crested cormorants (Phalacocorax auritus), laughing gulls (Leucophaues atricilla), homing pigeons (Columba livia) and western sandpipers (Calidris mauri) that were gavaged with a mixture of artificially weathered MC252 oil and food for either a single day or 4-5 consecutive days showed signs of oil toxicity. Where volume allowed, samples were collected for hematology, plasma protein electrophoresis, clinical chemistry and electrolytes, oxidative stress and organ weigh changes. Double-crested cormorants, laughing gulls and western sandpipers all excreted oil within 30min of dose, while pigeons regurgitated within less than one hour of dosing. There were species differences in the effectiveness of the dosing technique, with double-crested cormorants having the greatest number of responsive endpoints at the completion of the trial. Statistically significant changes in packed cell volume, white cell counts, alkaline phosphatase, alanine aminotransferase, creatine phosphokinase, gamma glutamyl transferase, uric acid, chloride, sodium, potassium, calcium, total glutathione, glutathione disulfide, reduced glutathione, spleen and liver weights were measured in double-crested cormorants. Homing pigeons had statistically significant changes in creatine phosphokinase, total glutathione, glutathione disulfide, reduced glutathione and Trolox equivalents. Laughing gulls exhibited statistically significant decreases in spleen and kidney weight, and no changes were observed in any measurement endpoints tested in western sandpipers. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Characterization and Comparison of Extended-Spectrum β-Lactamase (ESBL) Resistance Genotypes and Population Structure of Escherichia coli Isolated from Franklin's Gulls (Leucophaeus pipixcan) and Humans in Chile

    Science.gov (United States)

    Stedt, Johan; Bengtsson, Stina; Porczak, Aleksandra; Granholm, Susanne; González-Acuña, Daniel; Olsen, Björn; Bonnedahl, Jonas; Drobni, Mirva

    2013-01-01

    We investigated the general level of antibiotic resistance with further analysis of extended-spectrum beta-lactamase (ESBL) prevalence, as well as the population structure of E. coli in fecal flora of humans and Franklin’s gulls (Leucophaeus pipixcan) in central parts of Chile. We found a surprisingly high carriage rate of ESBL-producing E. coli among the gulls 112/372 (30.1%) as compared to the human population 6/49 (12.2%.) Several of the E. coli sequence types (STs) identified in birds have previously been reported as Multi Drug Resistant (MDR) human pathogens including the ability to produce ESBLs. This means that not only commensal flora is shared between birds and humans but also STs with pathogenic potential. Given the migratory behavior of Franklin’s gulls, they and other migratory species, may be a part of ESBL dissemination in the environment and over great geographic distances. Apart from keeping the antibiotic use low, breaking the transmission chains between the environment and humans must be a priority to hinder the dissemination of resistance. PMID:24098774

  14. Characterization and comparison of extended-spectrum β-lactamase (ESBL resistance genotypes and population structure of Escherichia coli isolated from Franklin's gulls (Leucophaeus pipixcan and humans in Chile.

    Directory of Open Access Journals (Sweden)

    Jorge Hernandez

    Full Text Available We investigated the general level of antibiotic resistance with further analysis of extended-spectrum beta-lactamase (ESBL prevalence, as well as the population structure of E. coli in fecal flora of humans and Franklin's gulls (Leucophaeus pipixcan in central parts of Chile. We found a surprisingly high carriage rate of ESBL-producing E. coli among the gulls 112/372 (30.1% as compared to the human population 6/49 (12.2%. Several of the E. coli sequence types (STs identified in birds have previously been reported as Multi Drug Resistant (MDR human pathogens including the ability to produce ESBLs. This means that not only commensal flora is shared between birds and humans but also STs with pathogenic potential. Given the migratory behavior of Franklin's gulls, they and other migratory species, may be a part of ESBL dissemination in the environment and over great geographic distances. Apart from keeping the antibiotic use low, breaking the transmission chains between the environment and humans must be a priority to hinder the dissemination of resistance.

  15. Glacial lake inventory and lake outburst potential in Uzbekistan.

    Science.gov (United States)

    Petrov, Maxim A; Sabitov, Timur Y; Tomashevskaya, Irina G; Glazirin, Gleb E; Chernomorets, Sergey S; Savernyuk, Elena A; Tutubalina, Olga V; Petrakov, Dmitriy A; Sokolov, Leonid S; Dokukin, Mikhail D; Mountrakis, Giorgos; Ruiz-Villanueva, Virginia; Stoffel, Markus

    2017-08-15

    Climate change has been shown to increase the number of mountain lakes across various mountain ranges in the World. In Central Asia, and in particular on the territory of Uzbekistan, a detailed assessment of glacier lakes and their evolution over time is, however lacking. For this reason we created the first detailed inventory of mountain lakes of Uzbekistan based on recent (2002-2014) satellite observations using WorldView-2, SPOT5, and IKONOS imagery with a spatial resolution from 2 to 10m. This record was complemented with data from field studies of the last 50years. The previous data were mostly in the form of inventories of lakes, available in Soviet archives, and primarily included localized in-situ data. The inventory of mountain lakes presented here, by contrast, includes an overview of all lakes of the territory of Uzbekistan. Lakes were considered if they were located at altitudes above 1500m and if lakes had an area exceeding 100m 2 . As in other mountain regions of the World, the ongoing increase of air temperatures has led to an increase in lake number and area. Moreover, the frequency and overall number of lake outburst events have been on the rise as well. Therefore, we also present the first outburst assessment with an updated version of well-known approaches considering local climate features and event histories. As a result, out of the 242 lakes identified on the territory of Uzbekistan, 15% are considered prone to outburst, 10% of these lakes have been assigned low outburst potential and the remainder of the lakes have an average level of outburst potential. We conclude that the distribution of lakes by elevation shows a significant influence on lake area and hazard potential. No significant differences, by contrast, exist between the distribution of lake area, outburst potential, and lake location with respect to glaciers by regions. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Between-year variability in the mixing of North Sea herring spawning components leads to pronounced variation in the composition of the catch

    DEFF Research Database (Denmark)

    Bierman, Stijn M.; Dickey-Collas, Mark; van Damme, Cindy J.G.

    2010-01-01

    North Sea herring (Clupea harengus) are managed as a single stock, but maintaining a diversity of spawning components is considered important. However, the total catch from each of these components cannot be estimated easily because the components mix during the summer feeding season. The spawning......-at-age between spawning components, in particular of the 2000 year class, may have caused the observed between-year changes in mixing of components. Our results indicate that estimates of compositions change when assumptions of perfect spatial mixing and perfect classification are relaxed, and can be uncertain...

  17. Disentangling the effects of evolutionary, demographic, and environmental factors influencing genetic structure of natural populations: Atlantic herring as a case study

    DEFF Research Database (Denmark)

    Gaggiotti, Oscar E.; Bekkevold, Dorte; Jørgensen, Hanne B.H.

    2009-01-01

    , on the other hand, seems to have been largely eroded, which is not surprising given the large reproductive potential and presumed enormous local effective population sizes of pelagic fish that constrain the effect of stochastic processes. The approach we used can in principle be applied to any abundant...... carried out separate analyses of neutral and selected genetic variation, which allowed us to establish that the two most important factors affecting population structure were selection due to salinity at spawning sites and feeding migrations. The genetic signal left by the demographic history of herring...

  18. Quantification of trypsin with a radioimmunoassay in herring larvae (Clupea harengus L.) compared with a highly sensitive fluorescence technique to determine tryptic enzyme activity

    International Nuclear Information System (INIS)

    Ueberschaer, B.; Pedersen, B.H.; Hjelmeland, K.

    1993-01-01

    Enzymatic activity and quantity of the protease trypsin were measured in individual herring larvae (Clupea harengus L.). The enzymatic activity assay was done by a fluorescence technique, and a radioimmunoassay was used for quantification of trypsin. The results are compared and the differences between the techniques discussed. Both methods have similar results, as high or low values in trypsin quantity were reflected in high or low values of tryptic activity. Quantity and activity were linearly and positively correlated, but small differences between methods were found at the lowest detection limits. Both techniques reflect the high variability between individual larvae. (orig.)

  19. Comparison of spatial and temporal trends of methoxylated PBDEs, PBDEs, and hexabromocyclododecane in herring along the Swedish coast

    Energy Technology Data Exchange (ETDEWEB)

    Asplund, L.; Nylund, K. [ITM, Stockholm Univ. (Sweden); Bignert, A. [Swedish Museum of Natural History, Stockholm (Sweden)

    2004-09-15

    Some brominated flame retardants, for example poly brominated diphenyl ethers (PBDEs) have been identified as ubiquitous environmental contaminants. The use of the technical PentaBDE product in the European Union has been drastically reduced in the last years and is banned from 2004, while another brominated flame retardant, hexabromocyclododecane (HBCD), continues to be used. In addition to the commercial BFR products, methoxylated PBDEs (MeO-PBDEs) have been identified in biota in the aquatic environment. The origin of the MeO-PBDEs is under discussion. To our knowledge, neither OH-PBDEs nor MeO-PBDEs are commercially produced, nor have they been reported as impurities in brominated technical products or formed as byproducts in any industrial process. However, MeO-PBDEs has been reported to be natural products formed in the marine environment. As regards MeO-PBDEs detected in Baltic fish several factors points in the direction of a natural origin. On the other hand, certain MeO-PBDEs detected in environmental samples could also be metabolites/environmental transformation products of PBDEs. Knowledge of the spatial and temporal trends of the flame retardants in biota can be very useful in identifying sources of emission to the environment and in evaluating the impacts of voluntary restrictions / bans (PBDEs) and ongoing use (HBCD) on environmental contamination. In addition, this knowledge could provide valuable help in identifying the origin of the MeO-PBDEs. To this end, the Swedish Environmental Monitoring Programme on Contaminants in Biota (SEMPC) has incorporated these 3 substance groups into its monitoring of organic contaminants in herring (Clupea harengus). In this contribution we report on the results of the first 4 years.

  20. The effects of pollutants on osmotic and ionic regulation of herring (Clupea harengus L. ) embryos and larvae

    Energy Technology Data Exchange (ETDEWEB)

    Ramsay, N.C. (Aberdeen Univ. (United Kingdom))

    1991-01-01

    This thesis looks at how osmoregulatory processes function during early ontogeny of herring (Clupea harengus L.) and how these can be affected by pollutants. First, during embryo osmoregulatory ontogeny, two distinct stages occur. Until the completion of epiboly and closure of the yolk plug, the embryo must rely wholly on passive osmoregulation. From epiboly to hatching, the embryo is able to regulate its osmolality and increases its water content through a drinking mechanism similar to that of the adult fish. Increased water content is paralleled by increased levels of solutes. The protein level thereafter decreases with subsequent increased ninhydrin positive substances. Excess salts are excreted through cells thought to be classical chloride cells. During the [open quotes]active[close quotes] osmoregulatory stage, the embryo has developed true osmotic homeostasis, providing continuity until the development of gills, skin, gut, kidney of the adult. Second, exposing embryos and larvae to a number of different pollutants affected parameters important for osmotic and ionic homeostasis. The most consistent response is an increased whole body electrolyte content and decreased water content, resulting in elevated osmolality. Exposure to drilling muds containing high levels of petrogenic components causes water loss from the larvae associated with a decreased drinking rate. Subsequent exposure to individual oil constituents at sublethal levels cause changes resulting in higher whole body electrolyte concentrations. In larvae exposed in vivo to metal levels below the Environmental Quality Standard, changes occurred in epithelial permeability. Effects on electrolyte concentrations also occurred in embryos but the mechanism was unclear. The mixture of heavy metals exposed in vitro resulted in a lower concentration required to cause a 50% reduction in whole body homogenate Na[sup +]K[sup +]-ATPase activity than for any individual metal.

  1. Lake Morphometry for NHD Lakes in Tennessee Region 6 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  2. Lake Morphometry for NHD Lakes in Ohio Region 5 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  3. Lake Morphometry for NHD Lakes in California Region 18 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  4. Temporal changes in tree-ring nitrogen of Pinus thunbergii trees exposed to Black-tailed Gull (Larus crassirostris) breeding colonies

    Energy Technology Data Exchange (ETDEWEB)

    Larry, Lopez C.M., E-mail: larry@iwate-u.ac.jp [United Graduate School of Agricultural Sciences, Iwate University, Morioka 020-8550 (Japan); Chitoshi, Mizota [Faculty of Agriculture, Iwate University, Morioka 020-8550 (Japan); Toshiro, Yamanaka [Division of Earth Science, Graduate School of Natural Science and Technology, Okayama University, 1-1, Naka 3-Chome, Tsushima, Okayama 700-8530 (Japan); Yoshihiro, Nobori [Faculty of Agriculture, Yamagata University, 1-23 Wakabamachi, Tsuruoka, Yamagata 997-8555 (Japan)

    2010-11-15

    Research highlights: {yields} N concentration and isotope ratio on tree-rings can be an important tool to infer past N soil conditions where trees grow. {yields} Changes in avian population on established or new breeding grounds caused by natural or anthropogenic mechanism could be inferred from the analysis shown in this paper. {yields} The property of trees to retain N concentration and N isotope characteristics is found in Pinus thunbergii. The use of other trees for similar analysis have to be determined because other species (Pinus densiflora, for example) do not have this property. - Abstract: Natural abundances of {sup 15}N/{sup 14}N ratios (commonly designated by {delta}{sup 15}N notation) of annual rings from Pinus thunbergii trees were determined after transplantation from a nursery to breeding colonies of Black-tailed Gull (Larus crassirostris) in Miyagi and Aomori and a control site in Yamagata, in northeastern Japan. Tree-rings were collected in July/August/September, 2009. Transplanting was conducted in the year 2000 in the Miyagi site, whereas there is no information about transplanting data in the Aomori and Yamagata sites. Soils associated with piscivorous (fish eating) avian colonies receive large seasonal input of organic N in the form of feces. The organic N is microbiologically transformed into inorganic N in soils, from which P. thunbergii derives its N. The resulting NH{sub 4}{sup -} and NO{sub 3}{sup -}N are characterized by distinctly heavy {delta}{sup 15}N ratios, due to coupled processes of mineralization, volatilization, nitrification and denitrification of feces. In general, total N concentration along with {delta}{sup 15}N values stored in the annual rings of P. thunbergii increased steadily after transplanting from the nursery to locations under continued avian N input. Tree-ring N content and isotopic ratios provided a reliable record of past annual available soil N caused by changes in the Black-tailed Gull population, and thus can

  5. Real-estate lakes

    Science.gov (United States)

    Rickert, David A.; Spieker, Andrew Maute

    1971-01-01

    Since the dawn of civilization waterfront land has been an irresistible attraction to man. Throughout history he has sought out locations fronting on oceans, rivers, and lakes. Originally sought for proximity .to water supply and transportation, such locations are now sought more for their esthetic qualities and for recreation. Usable natural waterfront property is limited, however, and the more desirable sites in many of our urban areas have already been taken. The lack of available waterfront sites has led to the creation of many artificial bodies of water. The rapid suburbanization that has characterized urban growth in America since the end of World War II, together with increasing affluence and le-isure time, has created a ready market for waterfront property. Accordingly, lake-centered subdivisions and developments dot the suburban landscape in many of our major urban areas. Literally thousands of lakes surrounded by homes have materialized during this period of rapid growth. Recently, several "new town" communities have been planned around this lake-centered concept. A lake can be either an asset or a liaoility to a community. A clean, clear, attractively landscaped lake is a definite asset, whereas a weed-choked, foul-smelling mudhole is a distinct liability. The urban environment poses both problems and imaginative opportunities in the development of lakes. Creation of a lake causes changes in all aspects of the environment. Hydrologic systems and ecological patterns are usually most severely altered. The developer should be aware of the potential changes; it is not sufficient merely to build a dam across a stream or to dig a hole in the ground. Development of Gl a successful lake requires careful planning for site selection and design, followed by thorough and cc ntinual management. The purpose of this report is to describe the characteristics of real-estate lakes, to pinpoint potential pmblems, and to suggest possible planning and management guidelines

  6. Lake Michigan lake trout PCB model forecast post audit

    Science.gov (United States)

    Scenario forecasts for total PCBs in Lake Michigan (LM) lake trout were conducted using the linked LM2-Toxics and LM Food Chain models, supported by a suite of additional LM models. Efforts were conducted under the Lake Michigan Mass Balance Study and the post audit represents th...

  7. Methane emissions from permafrost thaw lakes limited by lake drainage.

    NARCIS (Netherlands)

    van Huissteden, J.; Berrittella, C.; Parmentier, F.J.W.; Mi, Y.; Maximov, T.C.; Dolman, A.J.

    2011-01-01

    Thaw lakes in permafrost areas are sources of the strong greenhouse gas methane. They develop mostly in sedimentary lowlands with permafrost and a high excess ground ice volume, resulting in large areas covered with lakes and drained thaw-lake basins (DTLBs; refs,). Their expansion is enhanced by

  8. Great Lakes Environmental Database (GLENDA)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Great Lakes Environmental Database (GLENDA) houses environmental data on a wide variety of constituents in water, biota, sediment, and air in the Great Lakes area.

  9. Functional microbiology of soda lakes

    NARCIS (Netherlands)

    Sorokin, D.Y.; Banciu, H.L.; Muyzer, G.

    2015-01-01

    Soda lakes represent unique permanently haloalkaline system. Despite the harsh conditions, they are inhabited by abundant, mostly prokaryotic, microbial communities. This review summarizes results of studies of main functional groups of the soda lake prokaryotes responsible for carbon, nitrogen and

  10. Microplastic pollution in lakes and lake shoreline sediments - A case study on Lake Bolsena and Lake Chiusi (central Italy).

    Science.gov (United States)

    Fischer, Elke Kerstin; Paglialonga, Lisa; Czech, Elisa; Tamminga, Matthias

    2016-06-01

    Rivers and effluents have been identified as major pathways for microplastics of terrestrial sources. Moreover, lakes of different dimensions and even in remote locations contain microplastics in striking abundances. This study investigates concentrations of microplastic particles at two lakes in central Italy (Lake Bolsena, Lake Chiusi). A total number of six Manta Trawls have been carried out, two of them one day after heavy winds occurred on Lake Bolsena showing effects on particle distribution of fragments and fibers of varying size categories. Additionally, 36 sediment samples from lakeshores were analyzed for microplastic content. In the surface waters 2.68 to 3.36 particles/m(3) (Lake Chiusi) and 0.82 to 4.42 particles/m(3) (Lake Bolsena) were detected, respectively. Main differences between the lakes are attributed to lake characteristics such as surface and catchment area, depth and the presence of local wind patterns and tide range at Lake Bolsena. An event of heavy winds and moderate rainfall prior to one sampling led to an increase of concentrations at Lake Bolsena which is most probable related to lateral land-based and sewage effluent inputs. The abundances of microplastic particles in sediments vary from mean values of 112 (Lake Bolsena) to 234 particles/kg dry weight (Lake Chiusi). Lake Chiusi results reveal elevated fiber concentrations compared to those of Lake Bolsena what might be a result of higher organic content and a shift in grain size distribution towards the silt and clay fraction at the shallow and highly eutrophic Lake Chiusi. The distribution of particles along different beach levels revealed no significant differences. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Water quality of Lake Austin and Town Lake, Austin, Texas

    Science.gov (United States)

    Andrews, Freeman L.; Wells, Frank C.; Shelby, Wanda J.; McPherson, Emma

    1988-01-01

    Lake Austin and Town Lake are located on the Colorado River in Travis County, central Texas, and serve as a source of water for municipal and industrial water supplies, electrical-power generation, and recreation for more than 500,000 people in the Austin metropolitan area. Lake Austin, located immediately downstream of Lake Travis, extends for more than 20 miles into the western edge of the city of Austin. Town Lake extends through the downtown area of the city of Austin for nearly 6 miles where the Colorado River is impounded by Longhorn Dam.

  12. Lake Morphometry for NHD Lakes in Great Lakes Region 4 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  13. Transient Tsunamis in Lakes

    Science.gov (United States)

    Couston, L.; Mei, C.; Alam, M.

    2013-12-01

    A large number of lakes are surrounded by steep and unstable mountains with slopes prone to failure. As a result, landslides are likely to occur and impact water sitting in closed reservoirs. These rare geological phenomena pose serious threats to dam reservoirs and nearshore facilities because they can generate unexpectedly large tsunami waves. In fact, the tallest wave experienced by contemporary humans occurred because of a landslide in the narrow bay of Lituya in 1958, and five years later, a deadly landslide tsunami overtopped Lake Vajont's dam, flooding and damaging villages along the lakefront and in the Piave valley. If unstable slopes and potential slides are detected ahead of time, inundation maps can be drawn to help people know the risks, and mitigate the destructive power of the ensuing waves. These maps give the maximum wave runup height along the lake's vertical and sloping boundaries, and can be obtained by numerical simulations. Keeping track of the moving shorelines along beaches is challenging in classical Eulerian formulations because the horizontal extent of the fluid domain can change over time. As a result, assuming a solid slide and nonbreaking waves, here we develop a nonlinear shallow-water model equation in the Lagrangian framework to address the problem of transient landslide-tsunamis. In this manner, the shorelines' three-dimensional motion is part of the solution. The model equation is hyperbolic and can be solved numerically by finite differences. Here, a 4th order Runge-Kutta method and a compact finite-difference scheme are implemented to integrate in time and spatially discretize the forced shallow-water equation in Lagrangian coordinates. The formulation is applied to different lake and slide geometries to better understand the effects of the lake's finite lengths and slide's forcing mechanism on the generated wavefield. Specifically, for a slide moving down a plane beach, we show that edge-waves trapped by the shoreline and free

  14. Technologies for lake restoration

    Directory of Open Access Journals (Sweden)

    Helmut KLAPPER

    2003-09-01

    Full Text Available Lakes are suffering from different stress factors and need to be restored using different approaches. The eutrophication remains as the main water quality management problem for inland waters: both lakes and reservoirs. The way to curb the degradation is to stop the nutrient sources and to accelerate the restoration with help of in-lake technologies. Especially lakes with a long retention time need (eco- technological help to decrease the nutrient content in the free water. The microbial and other organic matter from sewage and other autochthonous biomasses, causes oxygen depletion, which has many adverse effects. In less developed countries big reservoirs function as sewage treatment plants. Natural aeration solves problems only partly and many pollutants tend to accumulate in the sediments. The acidification by acid rain and by pyrite oxidation has to be controlled by acid neutralizing technologies. Addition of alkaline chemicals is useful only for soft waters, and technologies for (microbial alkalinization of very acidic hardwater mining lakes are in development. The corrective measures differ from those in use for eutrophication control. The salinization and water shortage mostly occurs if more water is used than available. L. Aral, L. Tschad, the Dead Sea or L. Nasser belong to waters with most severe environmental problems on a global scale. Their hydrologic regime needs to be evaluated. The inflow of salt water at the bottom of some mining lakes adds to stability of stratification, and thus accumulation of hydrogen sulphide in the monimolimnion of the meromictic lakes. Destratification, which is the most used technology, is only restricted applicable because of the dangerous concentrations of the byproducts of biological degradation. The contamination of lakes with hazardous substances from industry and agriculture require different restoration technologies, including subhydric isolation and storage, addition of nutrients for better self

  15. Lakes on Mars

    CERN Document Server

    Cabrol, Nathalie A

    2014-01-01

    On Earth, lakes provide favorable environments for the development of life and its preservation as fossils. They are extremely sensitive to climate fluctuations and to conditions within their watersheds. As such, lakes are unique markers of the impact of environmental changes. Past and current missions have now demonstrated that water once flowed at the surface of Mars early in its history. Evidence of ancient ponding has been uncovered at scales ranging from a few kilometers to possibly that of the Arctic ocean. Whether life existed on Mars is still unknown; upcoming missions may find critic

  16. White-faced storm-petrels Pelagodroma marina predated by gulls as biological monitors of plastic pollution in the pelagic subtropical Northeast Atlantic.

    Science.gov (United States)

    Furtado, Ricardo; Menezes, Dilia; Santos, Carolina Jardim; Catry, Paulo

    2016-11-15

    Marine plastic pollution is rapidly growing and is a source of major concern. Seabirds often ingest plastic debris and are increasingly used as biological monitors of plastic pollution. However, virtually no studies have assessed plastics in seabirds in the deep subtropical North Atlantic. We investigated whether remains of white-faced storm-petrels (WFSP) present in gull pellets could be used for biomonitoring. We analysed 263 pellets and 79.0% of these contained plastic debris originating in the digestive tract of WFSP. Pellets with no bird prey did not contain plastics. Most debris were fragments (83.6%) with fewer plastic pellets (8.2%). Light-coloured plastics predominated (71.0%) and the most frequent polymer was HDPE (73.0%). Stable isotopes in toe-nails of WFSP containing many versus no plastics did not differ, indicating no individual specialisation leading to differential plastic ingestion. We suggest WFSP in pellets are highly suitable to monitor the little known pelagic subtropical Northeast Atlantic. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Terrestrial CDOM in Lakes of Yamal Peninsula: Connection to Lake and Lake Catchment Properties

    Directory of Open Access Journals (Sweden)

    Yury Dvornikov

    2018-01-01

    Full Text Available In this study, we analyze interactions in lake and lake catchment systems of a continuous permafrost area. We assessed colored dissolved organic matter (CDOM absorption at 440 nm (a(440CDOM and absorption slope (S300–500 in lakes using field sampling and optical remote sensing data for an area of 350 km2 in Central Yamal, Siberia. Applying a CDOM algorithm (ratio of green and red band reflectance for two high spatial resolution multispectral GeoEye-1 and Worldview-2 satellite images, we were able to extrapolate the a(λCDOM data from 18 lakes sampled in the field to 356 lakes in the study area (model R2 = 0.79. Values of a(440CDOM in 356 lakes varied from 0.48 to 8.35 m−1 with a median of 1.43 m−1. This a(λCDOM dataset was used to relate lake CDOM to 17 lake and lake catchment parameters derived from optical and radar remote sensing data and from digital elevation model analysis in order to establish the parameters controlling CDOM in lakes on the Yamal Peninsula. Regression tree model and boosted regression tree analysis showed that the activity of cryogenic processes (thermocirques in the lake shores and lake water level were the two most important controls, explaining 48.4% and 28.4% of lake CDOM, respectively (R2 = 0.61. Activation of thermocirques led to a large input of terrestrial organic matter and sediments from catchments and thawed permafrost to lakes (n = 15, mean a(440CDOM = 5.3 m−1. Large lakes on the floodplain with a connection to Mordy-Yakha River received more CDOM (n = 7, mean a(440CDOM = 3.8 m−1 compared to lakes located on higher terraces.

  18. Growth performance and survival of larval Atlantic herring, under the combined effects of elevated temperatures and CO2.

    Directory of Open Access Journals (Sweden)

    Michael Sswat

    Full Text Available In the coming decades, environmental change like warming and acidification will affect life in the ocean. While data on single stressor effects on fish are accumulating rapidly, we still know relatively little about interactive effects of multiple drivers. Of particular concern in this context are the early life stages of fish, for which direct effects of increased CO2 on growth and development have been observed. Whether these effects are further modified by elevated temperature was investigated here for the larvae of Atlantic herring (Clupea harengus, a commercially important fish species. Over a period of 32 days, larval survival, growth in size and weight, and instantaneous growth rate were assessed in a crossed experimental design of two temperatures (10°C and 12°C with two CO2 levels (400 μatm and 900 μatm CO2 at food levels mimicking natural levels using natural prey. Elevated temperature alone led to increased swimming activity, as well as decreased survival and instantaneous growth rate (Gi. The comparatively high sensitivity to elevated temperature in this study may have been influenced by low food levels offered to the larvae. Larval size, Gi and swimming activity were not affected by CO2, indicating tolerance of this species to projected "end of the century" CO2 levels. A synergistic effect of elevated temperature and CO2 was found for larval weight, where no effect of elevated CO2 concentrations was detected in the 12°C treatment, but a negative CO2 effect was found in the 10°C treatment. Contrasting CO2 effects were found for survival between the two temperatures. Under ambient CO2 conditions survival was increased at 12°C compared to 10°C. In general, CO2 effects were minor and considered negligible compared to the effect of temperature under these mimicked natural food conditions. These findings emphasize the need to include biotic factors such as energy supply via prey availability in future studies on interactive

  19. Poet Lake Crystal Approval

    Science.gov (United States)

    This September 19, 2016 letter from EPA approves the petition from Poet Biorefining-Lake Crystal, regarding non-grandfathered ethanol produced through a dry mill process, qualifying under the Clean Air Act for renewable fuel (D-code 6) RINs under the RFS

  20. Lake Kariba, Zimbabwe

    African Journals Online (AJOL)

    1984-02-01

    Feb 1, 1984 ... rings word opgesom terwyl sommige van die lesse wat by Kariba geleer is en 'n ... one area of the lake must have an effect, directly or indirectly, on other consumer organisms in the aquatic environment. Con- sidering ... are liable to attain their high density at the price of other taxa. ... be measured. Data on ...

  1. IN LAKE TANA, ETHIOPIA

    African Journals Online (AJOL)

    Turbidity showed depressed effect on biomass ... Key words/phrases: Biomass, duration of development, Lake Tana, large-turbid ... 36°45'-38°14'E and at an altitude of 1830 In, a.s.l. ... 30 cm mouth opening, 1.2 m cod end), which was ... times of the three copepods were measured under .... The greatest density values were.

  2. Lake whitefish diet, condition, and energy density in Lake Champlain and the lower four Great Lakes following dreissenid invasions

    Science.gov (United States)

    Herbst, Seth J.; Marsden, J. Ellen; Lantry, Brian F.

    2013-01-01

    Lake Whitefish Coregonus clupeaformis support some of the most valuable commercial freshwater fisheries in North America. Recent growth and condition decreases in Lake Whitefish populations in the Great Lakes have been attributed to the invasion of the dreissenid mussels, zebra mussels Dreissena polymorpha and quagga mussels D. bugensis, and the subsequent collapse of the amphipod, Diporeia, a once-abundant high energy prey source. Since 1993, Lake Champlain has also experienced the invasion and proliferation of zebra mussels, but in contrast to the Great Lakes, Diporeia were not historically abundant. We compared the diet, condition, and energy density of Lake Whitefish from Lake Champlain after the dreissenid mussel invasion to values for those of Lake Whitefish from Lakes Michigan, Huron, Erie, and Ontario. Lake Whitefish were collected using gill nets and bottom trawls, and their diets were quantified seasonally. Condition was estimated using Fulton's condition factor (K) and by determining energy density. In contrast to Lake Whitefish from some of the Great Lakes, those from Lake Champlain Lake Whitefish did not show a dietary shift towards dreissenid mussels, but instead fed primarily on fish eggs in spring, Mysis diluviana in summer, and gastropods and sphaeriids in fall and winter. Along with these dietary differences, the condition and energy density of Lake Whitefish from Lake Champlain were high compared with those of Lake Whitefish from Lakes Michigan, Huron, and Ontario after the dreissenid invasion, and were similar to Lake Whitefish from Lake Erie; fish from Lakes Michigan, Huron, and Ontario consumed dreissenids, whereas fish from Lake Erie did not. Our comparisons of Lake Whitefish populations in Lake Champlain to those in the Great Lakes indicate that diet and condition of Lake Champlain Lake Whitefish were not negatively affected by the dreissenid mussel invasion.

  3. Ecosystem scale acoustic sensing reveals humpback whale behavior synchronous with herring spawning processes and re-evaluation finds no effect of sonar on humpback song occurrence in the Gulf of Maine in fall 2006.

    Directory of Open Access Journals (Sweden)

    Zheng Gong

    Full Text Available We show that humpback-whale vocalization behavior is synchronous with peak annual Atlantic herring spawning processes in the Gulf of Maine. With a passive, wide-aperture, densely-sampled, coherent hydrophone array towed north of Georges Bank in a Fall 2006 Ocean Acoustic Waveguide Remote Sensing (OAWRS experiment, vocalizing whales could be instantaneously detected and localized over most of the Gulf of Maine ecosystem in a roughly 400-km diameter area by introducing array gain, of 18 dB, orders of magnitude higher than previously available in acoustic whale sensing. With humpback-whale vocalizations consistently recorded at roughly 2000/day, we show that vocalizing humpbacks (i were overwhelmingly distributed along the northern flank of Georges Bank, coinciding with the peak spawning time and location of Atlantic herring, and (ii their overall vocalization behavior was strongly diurnal, synchronous with the formation of large nocturnal herring shoals, with a call rate roughly ten-times higher at night than during the day. Humpback-whale vocalizations were comprised of (1 highly diurnal non-song calls, suited to hunting and feeding behavior, and (2 songs, which had constant occurrence rate over a diurnal cycle, invariant to diurnal herring shoaling. Before and during OAWRS survey transmissions: (a no vocalizing whales were found at Stellwagen Bank, which had negligible herring populations, and (b a constant humpback-whale song occurrence rate indicates the transmissions had no effect on humpback song. These measurements contradict the conclusions of Risch et al. Our analysis indicates that (a the song occurrence variation reported in Risch et al. is consistent with natural causes other than sonar, (b the reducing change in song reported in Risch et al. occurred days before the sonar survey began, and (c the Risch et al. method lacks the statistical significance to draw the conclusions of Risch et al. because it has a 98-100% false-positive rate

  4. Microbiology of Lonar Lake and other soda lakes

    Science.gov (United States)

    Paul Antony, Chakkiath; Kumaresan, Deepak; Hunger, Sindy; Drake, Harold L; Murrell, J Colin; Shouche, Yogesh S

    2013-01-01

    Soda lakes are saline and alkaline ecosystems that are believed to have existed throughout the geological record of Earth. They are widely distributed across the globe, but are highly abundant in terrestrial biomes such as deserts and steppes and in geologically interesting regions such as the East African Rift valley. The unusual geochemistry of these lakes supports the growth of an impressive array of microorganisms that are of ecological and economic importance. Haloalkaliphilic Bacteria and Archaea belonging to all major trophic groups have been described from many soda lakes, including lakes with exceptionally high levels of heavy metals. Lonar Lake is a soda lake that is centered at an unusual meteorite impact structure in the Deccan basalts in India and its key physicochemical and microbiological characteristics are highlighted in this article. The occurrence of diverse functional groups of microbes, such as methanogens, methanotrophs, phototrophs, denitrifiers, sulfur oxidizers, sulfate reducers and syntrophs in soda lakes, suggests that these habitats harbor complex microbial food webs that (a) interconnect various biological cycles via redox coupling and (b) impact on the production and consumption of greenhouse gases. Soda lake microorganisms harbor several biotechnologically relevant enzymes and biomolecules (for example, cellulases, amylases, ectoine) and there is the need to augment bioprospecting efforts in soda lake environments with new integrated approaches. Importantly, some saline and alkaline lake ecosystems around the world need to be protected from anthropogenic pressures that threaten their long-term existence. PMID:23178675

  5. Lake trout rehabilitation in Lake Erie: a case history

    Science.gov (United States)

    Cornelius, Floyd C.; Muth, Kenneth M.; Kenyon, Roger

    1995-01-01

    Native lake trout (Salvelinus namaycush) once thrived in the deep waters of eastern Lake Erie. The impact of nearly 70 years of unregulated exploitation and over 100 years of progressively severe cultural eutrophication resulted in the elimination of lake trout stocks by 1950. Early attempts to restore lake trout by stocking were unsuccessful in establishing a self-sustaining population. In the early 1980s, New York's Department of Environmental Conservation, Pennsylvania's Fish and Boat Commission, and the U.S. Fish and Wildlife Service entered into a cooperative program to rehabilitate lake trout in the eastern basin of Lake Erie. After 11 years of stocking selected strains of lake trout in U.S. waters, followed by effective sea lamprey control, lake trout appear to be successfully recolonizing their native habitat. Adult stocks have built up significantly and are expanding their range in the lake. Preliminary investigations suggest that lake trout reproductive habitat is still adequate for natural reproduction, but natural recruitment has not been documented. Future assessments will be directed toward evaluation of spawning success and tracking age-class cohorts as they move through the fishery.

  6. Age, growth, and maturity of the longnose sucker Catostomus catostomus, of western Lake Superior

    Science.gov (United States)

    Bailey, Merryll M.

    1969-01-01

    Studies of age, growth, and maturity were based on 1760 fish collected in western Lake Superior in 1964-65. The body:scale relation was curvilinear and the curve had an intercept of 1.65 inches on the length axis. The weight increased as the 2.85 power of the length. Some fish formed an annulus before May 18 in 1965; all had completed annuli by late September. Longnose suckers grew 3.6 inches the 1st year, reached 12 inches in the 6th year, and 18 inches in the 11th year. Fish from Pikes Bay grew faster than those from Gull Island Shoal. Over 6 years were required for weight to reach 1 lb and nearly 10 years to reach 2 lb. Minimum length at maturity was 10.5 inches for males and 11.5 inches for females. The youngest mature male belonged to age-group IV and the youngest mature female to age-group V. All males were mature at 14.5-14.9 inches (age-group VIII) and all females at 15.0-15.4 inches (age-group IX). Finclipped longnose suckers returned to spawn in the Brule River in successive years. One fish returned to spawn in 4 successive years. Many of the fish were not recaptured until 2 or 3 years after marking. The time of the Brule River spawning migration depended more on water temperature than on length of day. The average water temperature during the peak of the spawning runs of 1958-64 was 55.4 F. Larval suckers apparently spend little time in the Brule River and adjacent streams and drift downstream to the lake soon after hatching. The number of eggs in the ovaries of eight suckers ranged from 14 to 35 thousand and averaged 24 thousand for fish 13.9-17.7 inches long.

  7. Evolution of alkaline lakes - Lake Van case study

    Science.gov (United States)

    Tillman Meyer, Felix; Viehberg, Finn; Bahroun, Sonya; Wolf, Annabel; Immenhauser, Adrian; Kwiecien, Ola

    2017-04-01

    Lake Van in Eastern Anatolia (Turkey) is the largest terminal soda lake on Earth. The lake sedimentary profile covers ca. 600 ka (Stockhecke et al. 2014) Based on lithological changes, the presence of freshwater microfossils and close-to-freshwater pH value in the pore water, members of ICDP PALEOVAN concluded that Lake Van might have started as an open lake. Here we show paleontological and geochemical evidence in favour of this idea and constrain the time, when Lake Van likely transformed into a closed lake. Additionally we provide the first conceptual model of how this closure may have happened. Our archives of choice are inorganic and biogenic carbonates, separated by wet sieving. We identified microfossil assemblages (fraction > 125 µm) and performed high-resolution oxygen isotope (delta18O) and elemental (Mg/Ca, Sr/Ca) analyses of the fraction plants growing in the photic zone as food supply. These two aspects point to an increasing salinity in a shallowing lake. The delta18O values of inorganic carbonates are relatively low during the initial phase of Lake Van and increase abruptly (ca. 7‰) after 530 ka BP. At approximately the same time combination of Sr/Ca and Mg/Ca data suggest first occurrence of aragonite. Again, these findings suggest geochemical changes of the lake water concurrent with transition documented by microfossils. Comparison between Lake Van and Lake Ohrid (Lacey et al. 2016) delta18O data, precludes regional climate change (e.g.: increased evaporation) as the main driver of observed changes. With no evidence for increased volcanic or tectonic activity (e.g.: tephra layers, deformation structures, slumping) in the Lake Van sedimentary profile around 530 ka, it seems unlikely that a pyroclastic flow blocked the outflow of the lake. Alternatively, a portion of inflow has been diverged which might have caused a change in the hydrological balance and lake level falling below its outlet. However, as no geomorphological data confirming this

  8. Predicting Maximum Lake Depth from Surrounding Topography

    Science.gov (United States)

    Lake volume aids understanding of the physical and ecological dynamics of lakes, yet is often not readily available. The data needed to calculate lake volume (i.e. bathymetry) are usually only collected on a lake by lake basis and are difficult to obtain across broad regions. ...

  9. Lake-level frequency analysis for Devils Lake, North Dakota

    Science.gov (United States)

    Wiche, Gregg J.; Vecchia, Aldo V.

    1996-01-01

    Two approaches were used to estimate future lake-level probabilities for Devils Lake. The first approach is based on an annual lake-volume model, and the second approach is based on a statistical water mass-balance model that generates seasonal lake volumes on the basis of seasonal precipitation, evaporation, and inflow. Autoregressive moving average models were used to model the annual mean lake volume and the difference between the annual maximum lake volume and the annual mean lake volume. Residuals from both models were determined to be uncorrelated with zero mean and constant variance. However, a nonlinear relation between the residuals of the two models was included in the final annual lakevolume model.Because of high autocorrelation in the annual lake levels of Devils Lake, the annual lake-volume model was verified using annual lake-level changes. The annual lake-volume model closely reproduced the statistics of the recorded lake-level changes for 1901-93 except for the skewness coefficient. However, the model output is less skewed than the data indicate because of some unrealistically large lake-level declines. The statistical water mass-balance model requires as inputs seasonal precipitation, evaporation, and inflow data for Devils Lake. Analysis of annual precipitation, evaporation, and inflow data for 1950-93 revealed no significant trends or long-range dependence so the input time series were assumed to be stationary and short-range dependent.Normality transformations were used to approximately maintain the marginal probability distributions; and a multivariate, periodic autoregressive model was used to reproduce the correlation structure. Each of the coefficients in the model is significantly different from zero at the 5-percent significance level. Coefficients relating spring inflow from one year to spring and fall inflows from the previous year had the largest effect on the lake-level frequency analysis.Inclusion of parameter uncertainty in the model

  10. Lake-wide distribution of Dreissena in Lake Michigan, 1999

    Science.gov (United States)

    Fleischer, Guy W.; DeSorcie, Timothy J.; Holuszko, Jeffrey D.

    2001-01-01

    The Great Lakes Science Center has conducted lake-wide bottom trawl surveys of the fish community in Lake Michigan each fall since 1973. These systematic surveys are performed at depths of 9 to 110 m at each of seven index sites around Lake Michigan. Zebra mussel (Dreissena polymorpha) populations have expanded to all survey locations and at a level to sufficiently contribute to the bottom trawl catches. The quagga (Dreissena bugensis), recently reported in Lake Michigan, was likely in the catches though not recognized. Dreissena spp. biomass ranged from about 0.6 to 15 kg/ha at the various sites in 1999. Dreissenid mussels were found at depths of 9 to 82 m, with their peak biomass at 27 to 46 m. The colonization of these exotic mussels has ecological implications as well as potential ramifications on the ability to sample fish consistently and effectively with bottom trawls in Lake Michigan.

  11. The diversity of benthic mollusks of Lake Victoria and Lake Burigi ...

    African Journals Online (AJOL)

    Molluscan diversity, abundance and distribution in sediments of Lake Victoria and its satellite lake, Lake Burigi, were investigated. The survey was carried out in January and February 2002 for Lake Victoria and in March and April 2002 for Lake Burigi. Ten genera were recorded from four zones of Lake Victoria while only ...

  12. Gut content analysis of Lake Michigan waterbirds in years with avian botulism type E mortality, 2010–2012

    Science.gov (United States)

    Essian, David A.; Chipault, Jennifer G.; Lafrancois, Brenda M.; Leonard, Jill B.K.

    2016-01-01

    Waterbird die-offs caused by Clostridium botulinum neurotoxin type E (BoNT/E) have occurred sporadically in the Great Lakes since the late 1960s, with a recent pulse starting in the late 1990s. In recent die-offs, round gobies (Neogobius melanostomus) have been implicated as vectors for the transfer of BoNT/E to fish-eating birds due to the round goby invasion history and their importance as prey. Dreissenid mussels (Dreissena spp.) are also potentially involved in BoNT/E transmission to birds and round gobies. We examined gut contents of waterbirds collected in Lake Michigan during die-offs in 2010–2012, and the gut contents of culled, presumably BoNT/E-free double-crested cormorants (Phalacrocorax auritus). Round gobies were found in 86% of the BoNT/E-positive individuals, 84% of the BoNT/E-negative birds, and 94% of the BoNT/E-free cormorants examined. Double-crested cormorants, ring-billed gulls (Larus delewarensis), and common loons (Gavia immer) consumed larger-sized round gobies than horned and red-necked grebes (Podiceps auritus and Podiceps grisegena), white-winged scoters (Melanitta deglandi), and long-tailed ducks (Clangula hymealis). Other common prey included dreissenid mussels, terrestrial insects, and alewives (Alosa pseudoharengus). Our data emphasize the importance of round gobies and mussels in diets of Lake Michigan waterbirds and suggest they may play a role in the transfer of BoNT/E to waterbirds; however, round gobies and mussels were found in BoNT/E-positive, -negative, and -free individuals, suggesting that other factors, such as alternative trophic pathways for toxin transfer, bird migratory timing and feeding locations, prey behavior, and individual physiological differences across birds may affect the likelihood that a bird will succumb to BoNT/E intoxication.

  13. Elliot Lake progress report

    International Nuclear Information System (INIS)

    Findlay, W.; Scott, A.S.

    1980-01-01

    The intent of the Elliot Lake remedial program is to identify houses in Elliot Lake with annual average WL's in excess of 0.02, discover the routes of radon entry into identified houses and close enough of them to reduce the annual average WL to an acceptable level, and to demonstrate that the annual average WL is below 0.02 in houses where remedial work was not thought necessary as well as in houses where remedial work has been completed. The remedial program is organized into two subprograms, the survey program and the remedial action program. By December 31, 1979 more than 17000 survey measurements had been carried out, identifying 157 houses where remedial action was required and confirming that no action was needed in 413 houses. Remedial work had been completed on 98 houses

  14. Angora Fire, Lake Tahoe

    Science.gov (United States)

    2007-01-01

    On the weekend of June 23, 2007, a wildfire broke out south of Lake Tahoe, which stretches across the California-Nevada border. By June 28, the Angora Fire had burned more than 200 homes and forced some 2,000 residents to evacuate, according to The Seattle Times and the Central Valley Business Times. On June 27, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this image of the burn scar left by the Angora fire. The burn scar is dark gray, or charcoal. Water bodies, including the southern tip of Lake Tahoe and Fallen Leaf Lake, are pale silvery blue, the silver color a result of sunlight reflecting off the surface of the water. Vegetation ranges in color from dark to bright green. Streets are light gray, and the customary pattern of meandering residential streets and cul-de-sacs appears throughout the image, including the area that burned. The burn scar shows where the fire obliterated some of the residential areas just east of Fallen Leaf Lake. According to news reports, the U.S. Forest Service had expressed optimism about containing the fire within a week of the outbreak, but a few days after the fire started, it jumped a defense, forcing the evacuation of hundreds more residents. Strong winds that had been forecast for June 27, however, did not materialize, allowing firefighters to regain ground in controlling the blaze. On June 27, authorities hoped that the fire would be completely contained by July 3. According to estimates provided in the daily report from the National Interagency Fire Center, the fire had burned 3,100 acres (about 12.5 square kilometers) and was about 55 percent contained as of June 28. Some mandatory evacuations remained in effect. NASA image by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.

  15. Great Lakes Energy Institute

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, J. Iwan [Case Western Reserve Univ., Cleveland, OH (United States)

    2012-11-18

    The vision of the Great Lakes Energy Institute is to enable the transition to advanced, sustainable energy generation, storage, distribution and utilization through coordinated research, development, and education. The Institute will place emphasis on translating leading edge research into next generation energy technology. The Institute’s research thrusts focus on coordinated research in decentralized power generation devices (e.g. fuel cells, wind turbines, solar photovoltaic devices), management of electrical power transmission and distribution, energy storage, and energy efficiency.

  16. Limnology of Lake Midmar

    CSIR Research Space (South Africa)

    Breen, CM

    1983-12-01

    Full Text Available goals. Those which seem important to us are: the identification of the limnological responses affecting water quality which are of universal application. Some such as phosphorus load are well known whereas others may still require to be identified... Figure 17 Pattern of release of total nitrogen and phosphorus from decomposing vegetation ............................. 56 Figure 18 Changes in the amounts of total phosphorus within the lake, the inflow and the outflow on a weekly basis....... 59...

  17. Restoring life to acidified lakes

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, M

    1986-05-01

    In 1983 EPRI initiated the lake acidification mitigation project (LAMP) in order to examine the long-term ecosystem effects of liming lakes, and to develop a model for calculating optimal liming doses. Investigations were carried out at lakes under 3 sets of conditions: reacidification, maintenance liming and preventive maintenance liming. The research so far has indicated that liming is a safe and effective technique.

  18. Radioecological characteristics of Lake Zarnowieckie

    International Nuclear Information System (INIS)

    Soszka, G.J.; Grzybowska, D.; Rostek, J.; Pietruszewski, A.; Wardaszko, T.; Kalinowska, A.; Tomczak, J.

    1986-01-01

    Results are presented of the radioecological studies carried out in Lake Zarnowieckie as a part of pre-operational investigations related to the construction of a nuclear power station at this lake. Concentrations of essential radionuclides were determined in water, bottom sediments and selected plants and animals. Analyses were made of the distribution and spreading of 90 Sr and 137 Cs in the lake ecosystem and in the near-by meadows. 28 refs., 6 figs., 6 tabs. (author)

  19. Environmental Monitoring, Water Quality - Lakes Assessments - Attaining

    Data.gov (United States)

    NSGIC Education | GIS Inventory — This layer shows only attaining lakes of the Integrated List. The Lakes Integrated List represents lake assessments in an integrated format for the Clean Water Act...

  20. Atlantic Herring Acoustic Surveys

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Advanced Sampling Technologies Research Group conducts annual fisheries acoustic surveys using state-of-the-art acoustic, midwater trawling, and underwater...

  1. Red herring vaginal discharge.

    Science.gov (United States)

    Lee, Jun Hee; Pringle, Kirsty; Rajimwale, Ashok

    2013-09-18

    Labial hair tourniquet syndrome is a rare condition that can be easily misdiagnosed and ultimately lead to irreversible damage. An 11-year-old premenarche girl presented with a 5-day history of pain and swelling in the labia with associated vaginal discharge. The general practitioner treated her with clotrimazole without improvement. On examination, there was an oedematous swelling of the right labia with a proximal hair tourniquet. Local anaesthetic was applied and the hair removed with forceps. There was instant relief of pain and the discharge stopped within 24 h. The patient was sent home with a course of antibiotics.

  2. Argentina's nuclear red herring

    International Nuclear Information System (INIS)

    Perera, J.

    1983-01-01

    The article deals with Argentina's nuclear power programme over the last 30 years, including the country's efforts to be nuclear independent of the United States, as well as its aspirations to be a nuclear supplier to latin America. The latter policy on economic, rather than military grounds for nuclear weapons, has led to Argentina's decision to build a uranian enrichment plant. (U.K.)

  3. Algae Bloom in a Lake

    Directory of Open Access Journals (Sweden)

    David Sanabria

    2008-01-01

    Full Text Available The objective of this paper is to determine the likelihood of an algae bloom in a particular lake located in upstate New York. The growth of algae in this lake is caused by a high concentration of phosphorous that diffuses to the surface of the lake. Our calculations, based on Fick's Law, are used to create a mathematical model of the driving force of diffusion for phosphorous. Empirical observations are also used to predict whether the concentration of phosphorous will diffuse to the surface of this lake within a specified time and under specified conditions.

  4. Submerged Grove in Lake Onogawa

    OpenAIRE

    Sato, Yasuhiro; Nakamura, Soken; Ochiai, Masahiro

    1996-01-01

    Abstract : The first record by ultrasonic echo sounding on the distribution of the submerged standing trees on the bottom of Lake Onogawa is presented. Lake Onogawa is a dammed lake formed at the time of the eruption of the volcano Mt.Bandai in 1888. Since then the original vegetation of the dammed valley has remained submerged. Many submerged standing trees are distributed on the bottom within about 600m from the northeast end of the lake. The density of the trees in this area is sufficient ...

  5. Lake Charles CCS Project

    Energy Technology Data Exchange (ETDEWEB)

    Leib, Thomas [Leucadia Energy, LLC, Salt Lake City, UT (United States); Cole, Dan [Denbury Onshore, LLC, Plano, TX (United States)

    2015-06-30

    In late September 2014 development of the Lake Charles Clean Energy (LCCE) Plant was abandoned resulting in termination of Lake Charles Carbon Capture and Sequestration (CCS) Project which was a subset the LCCE Plant. As a result, the project was only funded through Phase 2A (Design) and did not enter Phase 2B (Construction) or Phase 2C (Operations). This report was prepared relying on information prepared and provided by engineering companies which were engaged by Leucadia Energy, LLC to prepare or review Front End Engineering and Design (FEED) for the Lake Charles Clean Energy Project, which includes the Carbon Capture and Sequestration (CCS) Project in Lake Charles, Louisiana. The Lake Charles Carbon Capture and Sequestration (CCS) Project was to be a large-scale industrial CCS project intended to demonstrate advanced technologies that capture and sequester carbon dioxide (CO2) emissions from industrial sources into underground formations. The Scope of work was divided into two discrete sections; 1) Capture and Compression prepared by the Recipient Leucadia Energy, LLC, and 2) Transport and Sequestration prepared by sub-Recipient Denbury Onshore, LLC. Capture and Compression-The Lake Charles CCS Project Final Technical Report describes the systems and equipment that would be necessary to capture CO2 generated in a large industrial gasification process and sequester the CO2 into underground formations. The purpose of each system is defined along with a description of its equipment and operation. Criteria for selection of major equipment are provided and ancillary utilities necessary for safe and reliable operation in compliance with environmental regulations are described. Construction considerations are described including a general arrangement of the CCS process units within the overall gasification project. A cost estimate is provided, delineated by system area with cost breakdown showing equipment, piping and materials

  6. Premature feather loss among common tern chicks in Ontario: the return of an enigmatic developmental anomaly

    Directory of Open Access Journals (Sweden)

    Jennifer M. Arnold

    2016-05-01

    Full Text Available In July 2014, we observed premature feather loss (PFL among non-sibling, common tern Sterna hirundo chicks between two and four weeks of age at Gull Island in northern Lake Ontario, Canada. Rarely observed in wild birds, to our knowledge PFL has not been recorded in terns since 1974, despite the subsequent banding of hundreds of thousands of tern chicks across North America alone. The prevalence, 5% of chicks (9/167, and extent of feather loss we report is more extreme than in previous reports for common terns but was not accompanied by other aberrant developmental or physical deformities. Complete feather loss from all body areas (wing, tail, head and body occurred over a period of a few days but all affected chicks appeared vigorous and quickly began to grow replacement feathers. All but one chick (recovered dead and submitted for post-mortem most likely fledged 10–20 days after normal fledging age. We found no evidence of feather dystrophy or concurrent developmental abnormalities unusual among affected chicks. Thus, the PFL we observed among common terns in 2014 was largely of unknown origin. There was striking temporal association between the onset of PFL and persistent strong southwesterly winds that caused extensive mixing of near-shore surface water with cool, deep lake waters. One hypothesis is that PFL may have been caused by unidentified pathogens or toxins welling up from these deep waters along the shoreline but current data are insufficient to test this. PFL was not observed among common terns at Gull Island in 2015, although we did observe similar feather loss in a herring gull Larus argentatus chick in that year. Comparison with sporadic records of PFL in other seabirds suggests that PFL may be a rare, but non-specific, response to a range of potential stressors. PFL is now known for gulls, penguins and terns.

  7. Holocene Lake-Level Fluctuations of Lake Aricota, Southern Peru

    Science.gov (United States)

    Placzek, Christa; Quade, Jay; Betancourt, Julio L.

    2001-09-01

    Lacustrine deposits exposed around Lake Aricota, Peru (17° 22‧S), a 7.5-km2 lake dammed by debris flows, provide a middle to late Holocene record of lake-level fluctuations. Chronological context for shoreline deposits was obtained from radiocarbon dating of vascular plant remains and other datable material with minimal 14C reservoir effects (<350 yr). Diatomites associated with highstands several meters above the modern lake level indicate wet episodes. Maximum Holocene lake level was attained before 6100 14C yr B.P. and ended ∼2700 14C yr B.P. Moderately high lake levels occurred at 1700 and 1300 14C yr B.P. The highstand at Lake Aricota during the middle Holocene is coeval with a major lowstand at Lake Titicaca (16°S), which is only 130 km to the northeast and shares a similar climatology. Comparisons with other marine and terrestrial records highlight emerging contradictions over the nature of mid-Holocene climate in the central Andes.

  8. PYRAMID LAKE RENEWEABLE ENERGY PLAN

    Energy Technology Data Exchange (ETDEWEB)

    HIGH DESERT GEOCULTURE, LLC

    2009-06-06

    The Pyramid Lake Renewable Energy Plan covers these areas: energy potential (primarily focusing on geothermal resource potential, but also more generally addressing wind energy potential); renewable energy market potential; transmission system development; geothermal direct use potential; and business structures to accomplish the development objectives of the Pyramid Lake Paiute Tribe.

  9. Choking Lake Winnipeg

    Science.gov (United States)

    Byrne, J. M.; Little, L. J.; Dodgson, K. A.; MacDonald, R. J.; Graham, J.

    2009-12-01

    The problems of waterway eutrophication and coastal zone hypoxia are reaching epidemic proportions. Fresh water and coastal marine environments around the world are suffering unprecedented pollution loadings. We are developing an education program to address the dramatic need for public, community and K-12 education about the harsh impacts of elevated nutrient loads on fresh and marine water environments. The Lake Winnipeg watershed is adopted as the poster child of fresh water eutrophication in western North America. The watershed, one of the largest on the continent, is in rapid decline due to pollution, population pressures and water diversion. A concerted education program is needed to change personal and society actions that negatively impact the Winnipeg watershed; and the confluence of the watershed - Lake Winnipeg. But the education program goes beyond Lake Winnipeg. Negative impacts of nutrient loads are adversely affecting environments right to the oceans. Major dead zones that are expanding on our continental shelves due to nutrient overloading threaten to coalesce into extensive regions of marine life die-off. This presentation outlines the documentary education production process under development. We are building a series of Public Service Announcements (PSAs) for national television networks. The PSAs will direct educators, stakeholders and citizens to an associated website with educational video clips detailing the issues of eutrophication and hypoxia. The video clips or webisodes, present interviews with leading scientists. The discussions address the causes of the problems, and presents workable solutions to nutrient overloads from a variety of sources. The webisodes are accompanied by notes and advice to teachers on ways and means to use the webisodes in classrooms. The project is fully funed by a group of Canadian Community Foundations, with the understanding the work wil be available free to educators anywhere in the world. Our education

  10. Lake Carnegie, Western Australia

    Science.gov (United States)

    2002-01-01

    Ephemeral Lake Carnegie, in Western Australia, fills with water only during periods of significant rainfall. In dry years, it is reduced to a muddy marsh. This image was acquired by Landsat 7's Enhanced Thematic Mapper plus (ETM+) sensor on May 19, 1999. This is a false-color composite image made using shortwave infrared, infrared, and red wavelengths. The image has also been sharpened using the sensor's panchromatic band. Image provided by the USGS EROS Data Center Satellite Systems Branch. This image is part of the ongoing Landsat Earth as Art series.

  11. L-Lake macroinvertebrate community

    Energy Technology Data Exchange (ETDEWEB)

    Specht, W.L.

    1996-06-01

    To characterize the present benthic macroinvertebrate community of L-Lake, Regions 5 and 7 of the reservoir were sampled in September 1995 at the same locations sampled in 1988 and 1989 during the L-Lake monitoring program. The macroinvertebrate community of 1995 is compared to that of 1988 and 1989. The species composition of L-Lake`s macroinvertebrate community has changed considerably since 1988-1989, due primarily to maturation of the reservoir ecosystem. L-Lake contains a reasonably diverse macroinvertebrate community that is capable of supporting higher trophic levels, including a diverse assemblage of fish species. The L-Lake macroinvertebrate community is similar to those of many other southeastern reservoirs, and there is no indication that the macroinvertebrate community is perturbed by chemical or physical stressors.

  12. L-Lake macroinvertebrate community

    International Nuclear Information System (INIS)

    Specht, W.L.

    1996-06-01

    To characterize the present benthic macroinvertebrate community of L-Lake, Regions 5 and 7 of the reservoir were sampled in September 1995 at the same locations sampled in 1988 and 1989 during the L-Lake monitoring program. The macroinvertebrate community of 1995 is compared to that of 1988 and 1989. The species composition of L-Lake's macroinvertebrate community has changed considerably since 1988-1989, due primarily to maturation of the reservoir ecosystem. L-Lake contains a reasonably diverse macroinvertebrate community that is capable of supporting higher trophic levels, including a diverse assemblage of fish species. The L-Lake macroinvertebrate community is similar to those of many other southeastern reservoirs, and there is no indication that the macroinvertebrate community is perturbed by chemical or physical stressors

  13. Effects of pressure reductions in a proposed siphon water lift system at St. Stephen Dam, South Carolina, on mortality rates of juvenile American shad and blueback herring. Technical report

    International Nuclear Information System (INIS)

    Nestler, J.M.; Schilt, C.R.; Jones, D.P.

    1998-09-01

    This report presents results of studies to predict the mortality rate of juvenile blueback herring (Alosa aestivalis) and American shad (A. sapidissima) associated with reduced pressure as they pass downstream through a proposed siphon water lift system at St. Stephen Dam, South Carolina. The primary function of the siphon is to increase attracting flow to better guide upstream migrating adult herring of both species into the existing fish lift for upstream passage. The US Army Engineer District, Charleston, wishes to consider the siphon as an alternative bypass route through the dam for downstream migrating juvenile and adult herring. A pressure-reduction testing system that emulates some of the pressure characteristics of the siphon was used to determine the approximate percentage of juvenile fishes that could be reasonably expected to be killed passing through the reduced pressures anticipated for the siphon water lift system. The testing system could duplicate the range of pressure change anticipated for the siphon lift system but could not obtain pressures lower than 4.1 psi, whereas pressures for some design alternatives may approach the theoretical minimum pressure of 0.0 psi. Study results indicate that the mortality rate is probably about 20 percent. Power analysis indicates that mortality rate above 30 percent is unlikely. Conducting additional mortality studies is recommended to refine predicted mortality rates. Measures should be taken to prevent juvenile fish from entering the siphon lift system if excessive mortality rates are observed

  14. Maternal effects mediated by egg quality in the Yellow-legged Gull Larus michahellis in relation to laying order and embryo sex

    Directory of Open Access Journals (Sweden)

    Caprioli Manuela

    2011-10-01

    Full Text Available Abstract Background Maternal effects mediated by egg size and quality may profoundly affect offspring development and performance, and mothers may adjust egg traits according to environmental or social influences. In avian species, context-dependency of maternal effects may result in variation in egg composition, as well as in differential patterns of covariation among selected egg components, according to, for example, position in the laying sequence or offspring sex. We investigated variation in major classes of egg yolk components (carotenoids, vitamins and steroid hormones in relation to egg size, position in the laying sequence and embryo sex in clutches of the Yellow-legged Gull (Larus michahellis. We also investigated their covariation, to highlight mutual adjustments, maternal constraints or trade-offs in egg allocation. Results Laying sequence-specific patterns of allocation emerged: concentration of carotenoids and vitamin E decreased, while concentrations of androgens increased. Vitamin A, estradiol and corticosterone did not show any change. There was no evidence of sex-specific allocation or covariation of yolk components. Concentrations of carotenoids and vitamins were positively correlated. Egg mass decreased along the laying sequence, and this decrease was negatively correlated with the mean concentrations of carotenoids in clutches, suggesting that nutritionally constrained females lay low quality clutches in terms of carotenoid content. Finally, clutches with smaller decline in antioxidants between first- and last-laid eggs had a larger increase in yolk corticosterone, suggesting that a smaller antioxidant depletion along the laying sequence may entail a cost for laying females in terms of increased stress levels. Conclusions Since some of the analyzed yolk components (e.g. testosterone and lutein are known to exert sex-specific phenotypic effects on the progeny in this species, the lack of sex-specific egg allocation by

  15. 75 FR 34934 - Safety Zone; Fireworks for the Virginia Lake Festival, Buggs Island Lake, Clarksville, VA

    Science.gov (United States)

    2010-06-21

    ...-AA00 Safety Zone; Fireworks for the Virginia Lake Festival, Buggs Island Lake, Clarksville, VA AGENCY... Fireworks for the Virginia Lake Festival event. This action is intended to restrict vessel traffic movement... Virginia Lake Festival, Buggs Island Lake, Clarksville, VA (a) Regulated Area. The following area is a...

  16. Holocene lake-level fluctuations of Lake Aricota, Southern Peru

    Science.gov (United States)

    Placzek, C.; Quade, Jay; Betancourt, J.L.

    2001-01-01

    Lacustrine deposits exposed around Lake Aricota, Peru (17?? 22???S), a 7.5-km2 lake dammed by debris flows, provide a middle to late Holocene record of lake-level fluctuations. Chronological context for shoreline deposits was obtained from radiocarbon dating of vascular plant remains and other datable material with minimal 14C reservoir effects (Titicaca (16?? S), which is only 130 km to the northeast and shares a similar climatology. Comparisons with other marine and terrestrial records highlight emerging contradictions over the nature of mid-Holocene climate in the central Andes. ?? 2001 University of Washington.

  17. Forest blowdown and lake acidification

    International Nuclear Information System (INIS)

    Dobson, J.E.; Rush, R.M.; Peplies, R.W.

    1990-01-01

    The authors examine the role of forest blowdown in lake acidification. The approach combines geographic information systems (GIS) and digital remote sensing with traditional field methods. The methods of analysis consist of direct observation, interpretation of satellite imagery and aerial photographs, and statistical comparison of two geographical distributions-one representing forest blow-down and another representing lake chemistry. Spatial and temporal associations between surface water pH and landscape disturbance are strong and consistent in the Adirondack Mountains of New York. In 43 Adirondack Mountain watersheds, lake pH is associated with the percentage of the watershed area blown down and with hydrogen ion deposition (Spearman rank correlation coefficients of -0.67 and -0.73, respectively). Evidence of a temporal association is found at Big Moose Lake and Jerseyfield Lake in New York and the Lygners Vider Plateau of Sweden. They conclude that forest blowdown facilities the acidification of some lakes by altering hydrologic pathways so that waters (previously acidified by acid deposition and/or other sources) do not experience the neutralization normally available through contact with subsurface soils and bedrock. Increased pipeflow is suggested as a mechanism that may link the biogeochemical impacts of forest blowdown to lake chemistry

  18. Microplastics in Taihu Lake, China.

    Science.gov (United States)

    Su, Lei; Xue, Yingang; Li, Lingyun; Yang, Dongqi; Kolandhasamy, Prabhu; Li, Daoji; Shi, Huahong

    2016-09-01

    In comparison with marine environments, the occurrence of microplastics in freshwater environments is less understood. In the present study, we investigated microplastic pollution levels during 2015 in Taihu Lake, the third largest Chinese lake located in one of the most developed areas of China. The abundance of microplastics reached 0.01 × 10(6)-6.8 × 10(6) items/km(2) in plankton net samples, 3.4-25.8 items/L in surface water, 11.0-234.6 items/kg dw in sediments and 0.2-12.5 items/g ww in Asian clams (Corbicula fluminea). The average abundance of microplastics was the highest in plankton net samples from the southeast area of the lake and in the sediments from the northwest area of the lake. The northwest area of the lake was the most heavily contaminated area of the lake, as indicated by chlorophyll-α and total phosphorus. The microplastics were dominated by fiber, 100-1000 μm in size and cellophane in composition. To our best knowledge, the microplastic levels measured in plankton net samples collected from Taihu Lake were the highest found in freshwater lakes worldwide. The ratio of the microplastics in clams to each sediment sample ranged from 38 to 3810 and was negatively correlated to the microplastic level in sediments. In brief, our results strongly suggest that high levels of microplastics occurred not only in water but also in organisms in Taihu Lake. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Key Lake spill. Final report

    International Nuclear Information System (INIS)

    1984-03-01

    On January 5, 1984 contaminated water overflowed a storage reservoir at the Key Lake uranium mill onto the ice on a neighboring lake, into a muskeg area and onto a road. Outflow continued for two days, partially undercutting a retaining dyke. This report concludes the spill was the result of poor operation by the Key Lake Mining Corp.. The environmental impact will be minimal after cleanup. Improvements can be made in the regulatory process, and it is necessary to prepare for possible future mishaps

  20. 2010 Great Lakes Restoration Initiative Bathymetric Lidar: Lake Superior

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data contained in this file contain hydrographic and topographic data collected by the Fugro LADS Mk II system along the Lake Superior coast of Minnessota,...

  1. Jordan Lake Watershed Protection District

    Data.gov (United States)

    Town of Chapel Hill, North Carolina — Polygon representing the area of the Jordan Lake Watershed Protection District. The Watershed Protection District (PDF) is a sensitive area of land that drains to...

  2. Great Lakes Environmental Research Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — NOAA-GLERL and its partners conduct innovative research on the dynamic environments and ecosystems of the Great Lakes and coastal regions to provide information for...

  3. Paleosecular variations from lake sediments

    International Nuclear Information System (INIS)

    Lund, S.P.; Banerjee, S.K.

    1979-01-01

    Data are presented on the secular variations of the magnetization of wet and dry lake sediments for 17 North American locations. The usefullness of this data in terms of the geomagnetic field is discussed

  4. Spatial distribution of seepage at a flow-through lake: Lake Hampen, Western Denmark

    DEFF Research Database (Denmark)

    Kidmose, Jacob Baarstrøm; Engesgaard, Peter Knudegaard; Nilsson, Bertel

    2011-01-01

    recharge patiern of the lake and relating these to the geologic history of the lake. Recharge of the surrounding aquifer by lake water occurs off shore in a narrow zone, as measured from lake–groundwater gradients. A 33-m-deep d18O profi le at the recharge side shows a lake d18O plume at depths...... that corroborates the interpretation of lake water recharging off shore and moving down gradient. Inclusion of lake bed heterogeneity in the model improved the comparison of simulated and observed discharge to the lake. The apparent age of the discharging groundwater to the lake was determined by CFCs, resulting...

  5. Can small zooplankton mix lakes?

    OpenAIRE

    Simoncelli, S.; Thackeray, S.J.; Wain, D.J.

    2017-01-01

    The idea that living organisms may contribute to turbulence and mixing in lakes and oceans (biomixing) dates to the 1960s, but has attracted increasing attention in recent years. Recent modeling and experimental studies suggest that marine organisms can enhance turbulence as much as winds and tides in oceans, with an impact on mixing. However, other studies show opposite and contradictory results, precluding definitive conclusions regarding the potential importance of biomixing. For lakes, on...

  6. Lake Turkana National Parks Kenya.

    OpenAIRE

    2005-01-01

    Lake Turkana is the largest, most northerly and most saline of Africa's Rift Valley lakes and an outstanding laboratory for the study of plant and animal communities. The three National Parks are a stopover for migrant waterfowl and are major breeding grounds for the Nile crocodile and hippopotamus. The Koobi Fora deposits are rich in pre-human, mammalian, molluscan and other fossil remains and have contributed more to the understanding of Quaternary palaeoenvironments than any other site on ...

  7. Radiocarbon dating of lake sediments

    OpenAIRE

    Pocevičius, Matas

    2016-01-01

    Matas Pocevičius, Radiocarbon dating of lake sediments, bachelor thesis, Vilnius University, Faculty of Physics, Department of General Physics and Spectroscopy, physics, Vilnius, 45 p., 2016. The aim of this study is to evaluate the possibility of radiocarbon dating application for Tapeliai lake bottom sediments. The literature review discusses topics related to accelerator mass spectrometry, principles of radiocarbon formation, importance of nuclear fallout for 14C, possible applications of ...

  8. How hype and glory gull

    International Nuclear Information System (INIS)

    Pinsdorf, M.K.

    1992-01-01

    Hyped expectations and lulling news, or no news translated as good news, are prescriptions for disasters. Such lulling encourages men to push themselves or their machines on missions impossible. It discourages constant vigilance or the plain speaking on which sound decisions must be made. Postdisaster, lulling intensifies the shock. When psychologically unprepared, victims are devastated more than necessary. This thesis will be illustrated by the historical example of Captain Robert F. Scott's 1910-1911 race to the South Pole against Roald Amundsen, the 1985 Challenger explosion, the 1986 Chernobyl nuclear accident, and the 1989 Exxon Valdez spill. Understanding the perils of treating such dangerous missions as milk runs will help managers avoid complacency, even accidents

  9. Aquatic macrophyte richness in Danish lakes in relation to alkalinity, transparency, and lake area

    DEFF Research Database (Denmark)

    Vestergaard, Ole Skafte; Sand-Jensen, Kaj

    2000-01-01

    We examined the relationship between environmental factors and the richness of submerged macrophytes species in 73 Danish lakes, which are mainly small, shallow, and have mesotrophic to hypertrophic conditions. We found that mean species richness per lake was only 4.5 in acid lakes of low...... alkalinity but 12.3 in lakes of high alkalinity due to a greater occurrence of the species-rich group of elodeids. Mean species richness per lake also increased significantly with increasing Secchi depth. No significant relationship between species richness and lake surface area was observed among the entire...... group of lakes or a subset of eutrophic lakes, as the growth of submerged macrophytes in large lakes may be restricted by wave action in shallow water and light restriction in deep water. In contrast, macrophyte species richness increased with lake surface area in transparent lakes, presumably due...

  10. Changes in Rongbuk lake and Imja lake in the Everest region of Himalaya

    Science.gov (United States)

    Chen, W.; Doko, T.; Liu, C.; Ichinose, T.; Fukui, H.; Feng, Q.; Gou, P.

    2014-12-01

    The Himalaya holds the world record in terms of range and elevation. It is one of the most extensively glacierized regions in the world except the Polar Regions. The Himalaya is a region sensitive to climate change. Changes in the glacial regime are indicators of global climate changes. Since the second half of the last century, most Himalayan glaciers have melted due to climate change. These changes directly affected the changes of glacial lakes in the Himalayan region due to the glacier retreat. New glacial lakes are formed, and a number of them have expanded in the Everest region of the Himalayas. This paper focuses on the two glacial lakes which are Imja Lake, located at the southern slope, and Rongbuk Lake, located at the northern slope in the Mt. Everest region, Himalaya to present the spatio-temporal changes from 1976 to 2008. Topographical conditions between two lakes were different (Kruskal-Wallis test, p < 0.05). Rongbuk Lake was located at 623 m higher than Imja Lake, and radiation of Rongbuk Lake was higher than the Imja Lake. Although size of Imja Lake was larger than the Rongbuk Lake in 2008, the growth speed of Rongbuk Lake was accelerating since 2000 and exceeds Imja Lake in 2000-2008. This trend of expansion of Rongbuk Lake is anticipated to be continued in the 21st century. Rongbuk Lake would be the biggest potential risk of glacial lake outburst flood (GLOF) at the Everest region of Himalaya in the future.

  11. Spruce Lake Dam reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, G. [SGE Acres Ltd., Fredericton, NB (Canada); Barnard, J. [SGE Acres Ltd., St. John' s, NF (Canada); Vriezen, C. [City of Saint John, NF (Canada); Stephenson, M. [Jacques Whitford Environment Ltd., Fredericton, NB (Canada)

    2004-09-01

    Spruce Lake Dam was constructed in 1898 as part of the water supply system for Saint John, New Brunswick. The original dam was a 6 meter high, 140 meter long concrete gravity dam with an intake structure at its mid point and an overflow spillway at the left abutment. A rehabilitation project was launched in 2001 to bring the deteriorated dam into conformance with the dam safety guidelines of the Canadian Dam Association. The project criteria included minimal disruption to normal operation of water supply facilities and no negative effect on water quality. The project involved installation of a new low level outlet, removal of a gate house and water intake pipes, replacement of an access road culvert in the spillway channel, and raising the earth dam section by 1.8 meters to allow for increased water storage. The new raised section has an impervious core. The project also involved site and geotechnical investigations as well as hydrotechnical and environmental studies. This presentation described the final design of the remedial work and the environmental permitting procedures. Raising the operating level of the system proved successful as demonstrated by the fewer number of pumping days required after dam rehabilitation. The dam safety assessment under the Canadian Environmental Assessment Act began in April 2001, and the rehabilitation was completed by the end of 2002. 1 tab., 8 figs.

  12. Spray Lakes reclamation project

    International Nuclear Information System (INIS)

    Zacaruk, M.R.

    1996-01-01

    When the level of the Spray Lakes (Alberta) reservoir was lowered by four metres, 208 ha of shoreline was exposed offering little to no wildlife benefit and only limited recreation potential. A reclamation plan for 128 ha of shoreline was therefore developed. A wild life-palatable, self-sustaining vegetation cover was established. Approximately 90 ha was scarified, and/or had tree stumps removed prior to seeding, while approximately 40 ha was seeded and fertilized only. The remaining 80 ha of shoreline was not revegetated due to limited access; these areas will be allowed to re-establish naturally from the forested edge. The species were selected based on their adaptation to alkaline soils, drought tolerance, persistence in a stand and rooting characteristics, as well as palatability to wildlife. Alfalfa, white clover and fall rye were seeded. In general, all areas of the reclamation plan are successfully revegetated. Areas which were recontoured are stable and non-eroding. Success was most significant in areas which had been scarified, then seeded and trackpacked. Areas that were seeded and fertilized only were less well established at the end of the first year, but showed improvement in the second and third years. The area will be monitored to ensure the reclaimed vegetation is self-sustaining

  13. The reproduction of lake trout in southern Lake Superior

    Science.gov (United States)

    Eschmeyer, Paul H.

    1955-01-01

    The principal spawning grounds of lake trout (Salvelinus namaycush namaycush) in United States waters of southern Lake Superior are on rocky shoals at depths of less than 20 fathoms. Most spawning occurs in October and early November. Of the mature fish collected on or near the spawning grounds, 60 to 69 percent were males. Among mature fish the average length of females was greater than that of males; few males less than 24 inches or females less than 26 inches in total length were caught. Recoveries of lake trout tagged on the spawning grounds showed that some males remained in the immediate area for a period of several weeks during the spawning season. Marked fish showed a tendency to return during later years to spawning grounds on which they had been tagged, even though many of them ranged long distances between spawning seasons.

  14. Recent warming of lake Kivu.

    Science.gov (United States)

    Katsev, Sergei; Aaberg, Arthur A; Crowe, Sean A; Hecky, Robert E

    2014-01-01

    Lake Kivu in East Africa has gained notoriety for its prodigious amounts of dissolved methane and dangers of limnic eruption. Being meromictic, it is also expected to accumulate heat due to rising regional air temperatures. To investigate the warming trend and distinguish between atmospheric and geothermal heating sources, we compiled historical temperature data, performed measurements with logging instruments, and simulated heat propagation. We also performed isotopic analyses of water from the lake's main basin and isolated Kabuno Bay. The results reveal that the lake surface is warming at the rate of 0.12°C per decade, which matches the warming rates in other East African lakes. Temperatures increase throughout the entire water column. Though warming is strongest near the surface, warming rates in the deep waters cannot be accounted for solely by propagation of atmospheric heat at presently assumed rates of vertical mixing. Unless the transport rates are significantly higher than presently believed, this indicates significant contributions from subterranean heat sources. Temperature time series in the deep monimolimnion suggest evidence of convection. The progressive deepening of the depth of temperature minimum in the water column is expected to accelerate the warming in deeper waters. The warming trend, however, is unlikely to strongly affect the physical stability of the lake, which depends primarily on salinity gradient.

  15. Recent warming of lake Kivu.

    Directory of Open Access Journals (Sweden)

    Sergei Katsev

    Full Text Available Lake Kivu in East Africa has gained notoriety for its prodigious amounts of dissolved methane and dangers of limnic eruption. Being meromictic, it is also expected to accumulate heat due to rising regional air temperatures. To investigate the warming trend and distinguish between atmospheric and geothermal heating sources, we compiled historical temperature data, performed measurements with logging instruments, and simulated heat propagation. We also performed isotopic analyses of water from the lake's main basin and isolated Kabuno Bay. The results reveal that the lake surface is warming at the rate of 0.12°C per decade, which matches the warming rates in other East African lakes. Temperatures increase throughout the entire water column. Though warming is strongest near the surface, warming rates in the deep waters cannot be accounted for solely by propagation of atmospheric heat at presently assumed rates of vertical mixing. Unless the transport rates are significantly higher than presently believed, this indicates significant contributions from subterranean heat sources. Temperature time series in the deep monimolimnion suggest evidence of convection. The progressive deepening of the depth of temperature minimum in the water column is expected to accelerate the warming in deeper waters. The warming trend, however, is unlikely to strongly affect the physical stability of the lake, which depends primarily on salinity gradient.

  16. 33 CFR 162.134 - Connecting waters from Lake Huron to Lake Erie; traffic rules.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; traffic rules. 162.134 Section 162.134 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.134 Connecting waters from Lake Huron to Lake Erie; traffic rules. (a) Detroit River. The...

  17. 33 CFR 162.132 - Connecting waters from Lake Huron to Lake Erie; communications rules.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; communications rules. 162.132 Section 162.132 Navigation and Navigable Waters COAST... NAVIGATION REGULATIONS § 162.132 Connecting waters from Lake Huron to Lake Erie; communications rules. (a...

  18. 33 CFR 162.130 - Connecting waters from Lake Huron to Lake Erie; general rules.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; general rules. 162.130 Section 162.130 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.130 Connecting waters from Lake Huron to Lake Erie; general rules. (a) Purpose. The...

  19. 33 CFR 162.138 - Connecting waters from Lake Huron to Lake Erie; speed rules.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; speed rules. 162.138 Section 162.138 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.138 Connecting waters from Lake Huron to Lake Erie; speed rules. (a) Maximum speed limit for...

  20. 33 CFR 162.136 - Connecting waters from Lake Huron to Lake Erie; anchorage grounds.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; anchorage grounds. 162.136 Section 162.136 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.136 Connecting waters from Lake Huron to Lake Erie; anchorage grounds. (a) In the Detroit...

  1. 33 CFR 162.140 - Connecting waters from Lake Huron to Lake Erie; miscellaneous rules.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; miscellaneous rules. 162.140 Section 162.140 Navigation and Navigable Waters COAST... NAVIGATION REGULATIONS § 162.140 Connecting waters from Lake Huron to Lake Erie; miscellaneous rules. (a...

  2. Energy density of lake whitefish Coregonus clupeaformis in Lakes Huron and Michigan

    Science.gov (United States)

    Pothoven, S.A.; Nalepa, T.F.; Madenjian, C.P.; Rediske, R.R.; Schneeberger, P.J.; He, J.X.

    2006-01-01

    We collected lake whitefish Coregonus clupeaformis off Alpena and Tawas City, Michigan, USA in Lake Huron and off Muskegon, Michigan USA in Lake Michigan during 2002–2004. We determined energy density and percent dry weight for lake whitefish from both lakes and lipid content for Lake Michigan fish. Energy density increased with increasing fish weight up to 800 g, and then remained relatively constant with further increases in fish weight. Energy density, adjusted for weight, was lower in Lake Huron than in Lake Michigan for both small (≤800 g) and large fish (>800 g). Energy density did not differ seasonally for small or large lake whitefish or between adult male and female fish. Energy density was strongly correlated with percent dry weight and percent lipid content. Based on data from commercially caught lake whitefish, body condition was lower in Lake Huron than Lake Michigan during 1981–2003, indicating that the dissimilarity in body condition between the lakes could be long standing. Energy density and lipid content in 2002–2004 in Lake Michigan were lower than data for comparable sized fish collected in 1969–1971. Differences in energy density between lakes were attributed to variation in diet and prey energy content as well as factors that affect feeding rates such as lake whitefish density and prey abundance.

  3. Preparation of aluminium lakes by electrocoagulation

    OpenAIRE

    Prapai Pradabkham

    2008-01-01

    Aluminium lakes have been prepared by electrocoagulation employing aluminium as electrodes. The electrocoagulation is conducted in an aqueous alcoholic solution and is completed within one hour. The dye content in the lake ranges approximately between 4-32%.

  4. Global Lake and River Ice Phenology Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Global Lake and River Ice Phenology Database contains freeze and thaw/breakup dates as well as other descriptive ice cover data for 865 lakes and rivers in the...

  5. Lake Tahoe Water Quality Improvement Programs

    Science.gov (United States)

    Information on the Lake Tahoe watershed, EPA's protection efforts, water quality issues, effects of climate, change, Lake Tahoe Total Maximum Daily Load (TMDL), EPA-sponsored projects, and list of partner agencies.

  6. Biota - 2011 Vegetation Inventory - Marsh Lake, MN

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — 2011 Vegetation Classification for Marsh Lake, MN Vegetation Project Report, OMBIL Environmental Stewardship - Level 1 Inventory. Marsh Lake is located on the...

  7. Zooplankton communities in a large prealpine lake, Lake Constance: comparison between the Upper and the Lower Lake

    Directory of Open Access Journals (Sweden)

    Gerhard MAIER

    2005-08-01

    Full Text Available The zooplankton communities of two basins of a large lake, Lake Constance, were compared during the years 2002 and 2003. The two basins differ in morphology, physical and chemical conditions. The Upper Lake basin has a surface area of 470 km2, a mean depth of 100 and a maximum depth of 250 m; the Lower Lake basin has a surface area of 62 km2, a mean depth of only 13 and a maximum depth of 40 m. Nutrient, chlorophyll-a concentrations and mean temperatures are somewhat higher in the Lower than in the Upper Lake. Total abundance of rotifers (number per m2 lake surface was higher and rotifer development started earlier in the year in the Lower than in the Upper Lake. Total abundance of crustaceans was higher in the Upper Lake in the year 2002; in the year 2003 no difference in abundance could be detected between the lake basins, although in summer crustacean abundance was higher in the Lower than in the Upper Lake. Crustacean communities differed significantly between lake basins while there was no apparent difference in rotifer communities. In the Lower Lake small crustaceans, like Bosmina spp., Ceriodaphnia pulchella and Thermocyclops oithonoides prevailed. Abundance (number per m2 lake surface of predatory cladocerans, large daphnids and large copepods was much lower in the Lower than in the Upper Lake, in particular during the summer months. Ordination with nonmetric multidimensional scaling (NMS separated communities of both lakes along gradients that correlated with temperature and chlorophyll a concentration. Clutches of copepods were larger in the Lower than in the Upper Lake. No difference could be detected in clutch size of large daphnids between lake basins. Our results show that zooplankton communities in different basins of Lake Constance can be very different. They further suggest that the lack of large crustaceans in particular the lack of large predatory cladocerans in the Lower Lake can have negative effects on growth and

  8. 33 CFR 162.220 - Hoover Dam, Lake Mead, and Lake Mohave (Colorado River), Ariz.-Nev.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Hoover Dam, Lake Mead, and Lake... REGULATIONS § 162.220 Hoover Dam, Lake Mead, and Lake Mohave (Colorado River), Ariz.-Nev. (a) Lake Mead and... the axis of Hoover Dam and that portion of Lake Mohave (Colorado River) extending 4,500 feet...

  9. lakemorpho: Calculating lake morphometry metrics in R.

    Science.gov (United States)

    Hollister, Jeffrey; Stachelek, Joseph

    2017-01-01

    Metrics describing the shape and size of lakes, known as lake morphometry metrics, are important for any limnological study. In cases where a lake has long been the subject of study these data are often already collected and are openly available. Many other lakes have these data collected, but access is challenging as it is often stored on individual computers (or worse, in filing cabinets) and is available only to the primary investigators. The vast majority of lakes fall into a third category in which the data are not available. This makes broad scale modelling of lake ecology a challenge as some of the key information about in-lake processes are unavailable. While this valuable in situ information may be difficult to obtain, several national datasets exist that may be used to model and estimate lake morphometry. In particular, digital elevation models and hydrography have been shown to be predictive of several lake morphometry metrics. The R package lakemorpho has been developed to utilize these data and estimate the following morphometry metrics: surface area, shoreline length, major axis length, minor axis length, major and minor axis length ratio, shoreline development, maximum depth, mean depth, volume, maximum lake length, mean lake width, maximum lake width, and fetch. In this software tool article we describe the motivation behind developing lakemorpho , discuss the implementation in R, and describe the use of lakemorpho with an example of a typical use case.

  10. Study of pollution in Rawal lake

    International Nuclear Information System (INIS)

    Ahmad, M.; Khan, M.I.A.; Nisar, M.; Kaleem, M.Y.

    1999-01-01

    It was intended to establish effects of pollution on quality of water of Rawal Lake, Islamabad. Six stations were located for collection of water. The data collected and analyzed so far indicated increasing pollution in the lake Increase in growth of hydrophytes in quite evident, leading towards process of eutrophication of the lake. (author)

  11. Decline of the world's saline lakes

    Science.gov (United States)

    Wayne A. Wurtsbaugh; Craig Miller; Sarah E. Null; R. Justin DeRose; Peter Wilcock; Maura Hahnenberger; Frank Howe; Johnnie Moore

    2017-01-01

    Many of the world’s saline lakes are shrinking at alarming rates, reducing waterbird habitat and economic benefits while threatening human health. Saline lakes are long-term basin-wide integrators of climatic conditions that shrink and grow with natural climatic variation. In contrast, water withdrawals for human use exert a sustained reduction in lake inflows and...

  12. A reactive nitrogen budget for Lake Michigan

    Science.gov (United States)

    The reactive nitrogen budget for Lake Michigan was reviewed and updated, making use of recent estimates of watershed and atmospheric nitrogen loads. The updated total N load to Lake Michigan was approximately double the previous estimate from the Lake Michigan Mass Balance study ...

  13. Historical changes to Lake Washington and route of the Lake Washington Ship Canal, King County, Washington

    Science.gov (United States)

    Chrzastowski, Michael J.

    1983-01-01

    Lake Washington, in the midst of the greater Seattle metropolitan area of the Puget Sound region (fig. 1), is an exceptional commercial, recreational, and esthetic resource for the region . In the past 130 years, Lake Washington has been changed from a " wild " lake in a wilderness setting to a regulated lake surrounded by a growing metropolis--a transformation that provides an unusual opportunity to study changes to a lake's shoreline and hydrologic characteristics -resulting from urbanization.

  14. First evidence of successful natural reproduction by planted lake trout in Lake Huron

    Science.gov (United States)

    Nester, Robert T.; Poe, Thomas P.

    1984-01-01

    Twenty-two lake trout (Salvelinus namaycush) swim-up fry, 24-27 mm long, were captured with emergent fry traps and a tow net in northwestern Lake Huron on a small nearshore reef off Alpena, Michigan, between May 10 and June 1, 1982. These catches represent the first evidence of successful production of swim-up fry by planted, hatchery-reared lake trout in Lake Huron since the lake trout rehabilitation program began in 1973.

  15. Horizontal drilling under Lake Erie

    Energy Technology Data Exchange (ETDEWEB)

    Meller, R.

    2001-07-01

    Drilling oil wells under Lake Erie calls for horizontal drilling wells to be drilled from shore out into the pay-zone under the lake. The nature and characteristics of horizontal wells as compared to vertical wells are explored. Considerations that have to be taken into account in drilling horizontal wells are explained (the degree of curvature, drilling fluid quality, geosteering in the pay-zone, steering instrumentation, measurements while drilling (MWD), logging while drilling (LWD)). The concept and reasons for extended reach wells are outlined, along with characteristic features of multilateral wells.

  16. The Lake and the City

    Directory of Open Access Journals (Sweden)

    Konstantin Lidin

    2013-09-01

    Full Text Available The article considers relations between the city of Irkutsk and Lake Baikal in terms of cultural geography. Baikal is included in the UNESCO world heritage list. Unlike the majority of lakes also included in this list, Baikal’s coast is inhabited, especially its southern part. Similar situation is, for example, in the cluster “the city of Bergen – Geiranger village – Geirangerfjord” in Norway. The comparative analysis shows how Norway’s positive experience of the system “a city – a village – a natural phenomenon” could be used in order to make Irkutsk more attractive for tourists and citizens.

  17. Protecting the endangered lake salmon

    International Nuclear Information System (INIS)

    Soimakallio, H.; Oesch, P.

    1997-01-01

    In addition to the Ringed Seal, the labyrinthine Saimaa lake system created after the Ice Age also trapped a species of salmon, whose entire life cycle became adapted to fresh water. In order to improve the living conditions of this lake salmon which - like the ringed seal - is today classified as an endangered species, an intensive research programme has been launched. The partners include the Finnish Game and Fisheries Research Institute, fishing and environmental authorities and - in collaboration with UPM-Kymmene Oy and Kuurnan Voima Oy - the IVO subsidiary Pamilo Oy

  18. LAKE BAIKAL: Underwater neutrino detector

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    A new underwater detector soon to be deployed in Lake Baikal in Siberia, the world's deepest lake with depths down to 1.7 kilometres, could help probe the deepest mysteries of physics. One of the big unsolved problems of astrophysics is the origin of very energetic cosmic rays. However there are many ideas on how particles could be accelerated by exotic concentrations of matter and provide the majority of the Galaxy's high energy particles. Clarification would come from new detectors picking up the energetic photons and neutrinos from these sources

  19. Protecting the endangered lake salmon

    Energy Technology Data Exchange (ETDEWEB)

    Soimakallio, H.; Oesch, P. [ed.

    1997-11-01

    In addition to the Ringed Seal, the labyrinthine Saimaa lake system created after the Ice Age also trapped a species of salmon, whose entire life cycle became adapted to fresh water. In order to improve the living conditions of this lake salmon which - like the ringed seal - is today classified as an endangered species, an intensive research programme has been launched. The partners include the Finnish Game and Fisheries Research Institute, fishing and environmental authorities and - in collaboration with UPM-Kymmene Oy and Kuurnan Voima Oy - the IVO subsidiary Pamilo Oy

  20. Post Audit of Lake Michigan Lake Trout PCB Model Forecasts

    Science.gov (United States)

    The Lake Michigan (LM) Mass Balance Study was conducted to measure and model polychlorinated biphenyls (PCBs) and other anthropogenic substances to gain a better understanding of the transport, fate, and effects of these substances within the system and to aid managers in the env...