Use of preserved museum fish to evaluate historical and current mercury contamination in fish from two rivers in Oklahoma, USA.

Science.gov (United States)

Hill, J Jaron; Chumchal, Matthew M; Drenner, Ray W; Pinder, John E; Drenner, S Matthew

2010-02-01

We examined the effects of a commonly used preservation technique on mercury concentration in fish tissue. After fixing fish muscle tissue in formalin followed by preservation in isopropanol, we found that mercury concentration in fish muscle tissue increased by 18%, reaching an asymptote after 40 days. We used formalin-isopropanol-preserved longear sunfish (Lepomis megalotis) from the Sam Noble Oklahoma Museum of Natural History to examine historical changes and predict current mercury concentrations in fish from two rivers in southeastern Oklahoma. Glover River was free-flowing, while Mountain Fork River was impounded in 1970 and a coldwater trout fishery was established upstream from the collection site in 1989. Mercury concentrations in longear sunfish from Glover River showed no historical changes from 1963 to 2001. Mercury concentrations in longear sunfish from Mountain Fork River showed no change from 1925 to 1993 but declined significantly from 1993 to 2003. We also compared mercury concentrations of the most recently collected longear sunfish in the museum to mercury concentrations of unpreserved fish collected from the rivers in 2006. Concentrations of mercury in museum fish were not significantly different from mercury concentrations in unpreserved fish we collected from the rivers. Our study indicates that preserved museum fish specimens can be used to evaluate historical changes and predict current levels of mercury contamination in fish.

Comparison of plasma and tissue disposition of enrofloxacin in rainbow trout (Oncorhynchus mykiss) and common carp (Cyprinus carpio) after a single oral administration.

Science.gov (United States)

Kyuchukova, Ralica; Milanova, Aneliya; Pavlov, Alexander; Lashev, Lubomir

2015-01-01

The aim of the study was to investigate the serum and tissue disposition of enrofloxacin and its active metabolite ciprofloxacin in rainbow trout (Oncorhynchus mykiss) and common carp (Cyprinus carpio) after a single oral administration at a dose of 10 mg kg(-1). Concentrations of enrofloxacin in the serum of rainbow trout showed high variability with two peaks at the third and 24th hour after administration. The highest concentrations were found in the liver. The curves of liver levels showed similar changes to the respective serum samples. In the muscles, enrofloxacin concentrations were also higher compared with the respective serum samples. Ciprofloxacin concentrations were lower and showed smaller variations in all investigated tissues. The serum and tissue concentrations of enrofloxacin and ciprofloxacin in common carp showed two peaks, with the first Cmax at the third hour after drug administration as in rainbow trout. Concentrations of both investigated substances were higher in the liver than in the serum. The differences in common carp were less pronounced in comparison with rainbow trout. Relatively high levels of both substances were found in the muscles. Seven days after treatment enrofloxacin concentrations in the serum and tissues were within the therapeutic levels for most of the sensitive microorganisms in trout. Lower concentrations of its metabolite ciprofloxacin were found in the investigated tissues at the last sampling point. Lower levels of both substances were found in carp.

Determination of niclosamide residues in rainbow trout (Oncorhynchus mykiss) and channel catfish (Ictalurus punctatus) fillet tissue by high-performance liquid chromatography

Science.gov (United States)

Schreier, Theresa M.; Dawson, V.K.; Cho, Yirang; Spanjers, N.J.; Boogaard, M.A.

2000-01-01

Bayluscide [the ethanolamine salt of niclosamide (NIC)] is a registered piscicide used in combination with 3-(trifluoromethyl)-4-nitrophenol (TFM) to control sea lamprey populations in streams tributary to the Great Lakes. A high-performance liquid chromatography (HPLC) method was developed for the determination of NIC residues in muscle fillet tissues of fish exposed to NIC and TFM during sea lamprey control treatments. NIC was extracted from fortified channel catfish and rainbow trout fillet tissue with a series of acetone extractions and cleaned up on C-18 solid-phase extraction cartridges. NIC concentrations were determined by HPLC with detection at 360 and 335 nm for rainbow trout and catfish, respectively. Recovery of NIC from rainbow trout (n = 7) fortified at 0.04 mu g/g was 77 +/- 6.5% and from channel catfish (n = 7) fortified at 0.02 mu g/g was 113 +/- 11%. NIC detection limit was 0.0107 mu g/g for rainbow trout and 0.0063 mu g/g for catfish. Percent recovery of incurred radioactive residues by this method from catfish exposed to [C-14]NIC was 89.3 +/- 4.1%. Percent recoveries of NIC from fortified storage stability tissue samples for rainbow trout (n = 3) analyzed at 5 and 7.5 month periods were 78 +/- 5.1 and 68 +/- 2.4%, respectively. Percent recoveries of NIC from fortified storage stability tissue samples for channel catfish (n = 3) analyzed at 5 and 7.5 month periods were 88 +/- 13 and 76 +/- 21%, respectively.

Total mercury distribution in different tissues of six species of freshwater fish from the Kpong hydroelectric reservoir in Ghana.

Science.gov (United States)

Atta, Alhassan; Voegborlo, Ray Bright; Agorku, Eric Selorm

2012-05-01

Total mercury concentrations were determined in seven tissues of 38 fish samples comprising six species from the Kpong hydroelectric reservoir in Ghana by cold vapour atomic absorption spectrometry technique using an automatic mercury analyzer. Mercury concentration in all the tissues ranged from 0.005 to 0.022 μg/g wet weight. In general, the concentration of mercury in all the tissues were decreasing in the order; liver > muscle > intestine > stomach > gonad > gill > swim bladder. Mercury concentration was generally greater in the tissues of high-trophic-level fish such as Clarotes laticeps, Mormyrops anguilloides and Chrysichthys aurutus whereas low-trophic-level fish such as Oreochromis niloticus recorded low mercury concentration in their tissues. The results obtained for total mercury concentration in the muscle tissues analysed in this study are below the WHO/FAO threshold limit of 0.5 μg/g. This suggests that the exposure of the general public to Hg through fish consumption can be considered negligible.

Multi-tissue analyses reveal limited inter-annual and seasonal variation in mercury exposure in an Antarctic penguin community.

Science.gov (United States)

Brasso, Rebecka L; Polito, Michael J; Emslie, Steven D

2014-10-01

Inter-annual variation in tissue mercury concentrations in birds can result from annual changes in the bioavailability of mercury or shifts in dietary composition and/or trophic level. We investigated potential annual variability in mercury dynamics in the Antarctic marine food web using Pygoscelis penguins as biomonitors. Eggshell membrane, chick down, and adult feathers were collected from three species of sympatrically breeding Pygoscelis penguins during the austral summers of 2006/2007-2010/2011. To evaluate the hypothesis that mercury concentrations in penguins exhibit significant inter-annual variation and to determine the potential source of such variation (dietary or environmental), we compared tissue mercury concentrations with trophic levels as indicated by δ(15)N values from all species and tissues. Overall, no inter-annual variation in mercury was observed in adult feathers suggesting that mercury exposure, on an annual scale, was consistent for Pygoscelis penguins. However, when examining tissues that reflected more discrete time periods (chick down and eggshell membrane) relative to adult feathers, we found some evidence of inter-annual variation in mercury exposure during penguins' pre-breeding and chick rearing periods. Evidence of inter-annual variation in penguin trophic level was also limited suggesting that foraging ecology and environmental factors related to the bioavailability of mercury may provide more explanatory power for mercury exposure compared to trophic level alone. Even so, the variable strength of relationships observed between trophic level and tissue mercury concentrations across and within Pygoscelis penguin species suggest that caution is required when selecting appropriate species and tissue combinations for environmental biomonitoring studies in Antarctica.

Genetic Inventory of Bull Trout and Westslope Cutthroat Trout in the Pend Oreille Subbasin, 2002-2003 Annual Report.

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Maroney, Joseph R. (Kalispel Tribe of Indians, Usk, WA); Shaklee, James B.; Young, Sewall F. (Washington Department of Fish and Wildlife, Olympia, WA)

2003-10-01

In 2002, the Kalispel Natural Resource Department (KNRD) collected tissue samples for genetic analysis from 280 bull trout and 940 westslope cutthroat. The Washington Department of Fish and Wildlife developed and applied microsatellite DNA screening protocols for the analysis of bull trout at 13 loci and 24 loci for cutthroat trout. This project will continue collection and analysis of additional samples for the next 2 years. At that time, a final annual report will be compiled for the three-year study that will describe the genetic characteristics for bull trout and westslope cutthroat trout. The extent of hybridization of bull trout (with brook trout) and westslope cutthroat trout (with Yellowstone cutthroat trout and rainbow trout) in the Priest Lake and Lower Pend Oreille subbasins will also be examined.

Mercury and selenium levels, and selenium:mercury molar ratios of brain, muscle and other tissues in bluefish (Pomatomus saltatrix) from New Jersey, USA

Science.gov (United States)

Burger, Joanna; Jeitner, Christian; Donio, Mark; Pittfield, Taryn; Gochfeld, Michael

2015-01-01

A number of contaminants affect fish health, including mercury and selenium, and the selenium: mercury molar ratio. Recently the protective effects of selenium on methylmercury toxicity have been publicized, particularly for consumption of saltwater fish. Yet the relative ameliorating effects of selenium on toxicity within fish have not been examined, nor has the molar ratio in different tissues, (i.e. brain). We examined mercury and selenium levels in brain, kidney, liver, red and white muscle, and skin and scales in bluefish (Pomatomus saltatrix) from New Jersey to determine whether there were toxic levels of either metal, and we computed the selenium: mercury molar ratios by tissues. Total mercury averaged 0.32 ± 0.02 ppm wet weight in edible muscle and 0.09 ± 0.01 ppm in brain. Selenium concentration averaged 0.37 ± 0.03 in muscle and 0.36 ± 0.03 ppm in brain. There were significant differences in levels of mercury, selenium, and selenium: mercury molar ratios, among tissues. Mercury and selenium levels were correlated in kidney and skin/scales. Mercury levels were highest in kidney, intermediate in muscle and liver, and lowest in brain and skin/scales; selenium levels were also highest in kidney, intermediate in liver, and were an order of magnitude lower in the white muscle and brain. Mercury levels in muscle, kidney and skin/scales were positively correlated with fish size (length). Selenium levels in muscle, kidney and liver were positively correlated with fish length, but in brain; selenium levels were negatively correlated with fish length. The selenium: mercury molar ratio was negatively correlated with fish length for white muscle, liver, kidney, and brain, particularly for fish over 50 cm in length, suggesting that older fish experience less protective advantages of selenium against mercury toxicity than smaller fish, and that consumers of bluefish similarly receive less advantage from eating larger fish. PMID:23202378

Wet and Dry Atmospheric Mercury Deposition Accumulates in Watersheds of the Northeastern United States

Science.gov (United States)

Boyer, E. W.; Grant, C.; Grimm, J.; Drohan, P. J.; Bennett, J.; Lawler, D.

2013-12-01

Mercury emissions to the atmosphere from coal-fired power plants and other sources such as waste incineration can be deposited to landscapes in precipitation and in dry fallout. Some mercury reaches watersheds and streams, where it can accumulate in sediments and biota. Human exposure to mercury occurs primarily through fish consumption, and currently mercury fish eating advisories are in place for many of the streams and lakes in the state. Here, we explored mercury in air, soils, water, and biota. To quantify atmospheric mercury deposition, we measured both wet and dry mercury deposition at over 10 locations in Pennsylvania, from which we present variation in mercury deposition and initial assessments of factors affecting the patterns. Further, we simulated mercury deposition at unmonitored locations in Pennsylvania and the northeastern United States over space and time with a high-resolution modeling technique that reflects storm tracks and air flow patterns. To consider mercury accumulation in watersheds, we collected data on soil mercury concentrations in a set of soil samples, and collected baseline data on mercury in streams draining 35 forested watersheds across Pennsylvania, spanning gradients of atmospheric deposition, climate and geology. Mercury concentrations were measured in stream water under base-flow conditions, in streambed sediments, aquatic mosses, and in fish tissues from brook trout. Results indicate that wet and dry atmospheric deposition is a primary source of mercury that is accumulating in watersheds of Pennsylvania and the northeastern United States.

Using river distance and existing hydrography data can improve the geostatistical estimation of fish tissue mercury at unsampled locations.

Science.gov (United States)

Money, Eric S; Sackett, Dana K; Aday, D Derek; Serre, Marc L

2011-09-15

Mercury in fish tissue is a major human health concern. Consumption of mercury-contaminated fish poses risks to the general population, including potentially serious developmental defects and neurological damage in young children. Therefore, it is important to accurately identify areas that have the potential for high levels of bioaccumulated mercury. However, due to time and resource constraints, it is difficult to adequately assess fish tissue mercury on a basin wide scale. We hypothesized that, given the nature of fish movement along streams, an analytical approach that takes into account distance traveled along these streams would improve the estimation accuracy for fish tissue mercury in unsampled streams. Therefore, we used a river-based Bayesian Maximum Entropy framework (river-BME) for modern space/time geostatistics to estimate fish tissue mercury at unsampled locations in the Cape Fear and Lumber Basins in eastern North Carolina. We also compared the space/time geostatistical estimation using river-BME to the more traditional Euclidean-based BME approach, with and without the inclusion of a secondary variable. Results showed that this river-based approach reduced the estimation error of fish tissue mercury by more than 13% and that the median estimate of fish tissue mercury exceeded the EPA action level of 0.3 ppm in more than 90% of river miles for the study domain.

Mercury concentrations in seabird tissues from Machias Seal Island, New Brunswick, Canada

Energy Technology Data Exchange (ETDEWEB)

Bond, Alexander L., E-mail: abond@mun.ca [Atlantic Cooperative Wildlife Ecology Research Network, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick, E3B 5A3 (Canada); Department of Biology, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick, E3B 5A3 (Canada); Diamond, Antony W. [Atlantic Cooperative Wildlife Ecology Research Network, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick, E3B 5A3 (Canada); Department of Biology, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick, E3B 5A3 (Canada)

2009-07-01

Mercury is a pervasive environmental contaminant, the anthropogenic portion of which is increasing globally, and in northeastern North America in particular. Seabirds frequently are used as indicators of the marine environment, including mercury contamination. We analysed paired samples for total mercury (Hg) concentrations in feathers and blood from adult and chick, albumen, and lipid-free yolk of seven seabirds breeding on Machias Seal Island, New Brunswick, Canada - Arctic Tern (Sterna paradisaea), Atlantic Puffin (Fratercula arctica), Common Eider (Somateria mollissima), Common Murre (Uria aalge), Common Tern (Sterna hirundo), Leach's Storm-petrel (Oceanodroma leucorhoa), and Razorbill (Alca torda). We also used stable-isotope ratios of carbon ({delta}{sup 13}C), and nitrogen ({delta}{sup 15}N) to evaluate the relationship between carbon source and trophic position and mercury. We found high Hg concentrations across tissue types in Leach's Storm-petrels, and Razorbills, with lower concentrations in other species, the lowest being in Common Eiders. Storm-petrels prey on mesopelagic fish that accumulate mercury, and Razorbills feed on larger, older fish that bioaccumulate heavy metals. Biomagnification of Hg, or the increase in Hg concentration with trophic position as measured by {delta}{sup 15}N, was significant and greater in albumen than other tissues, whereas in other tissues, {delta}{sup 15}N explained little of the overall variation in Hg concentration. Hg concentrations in egg components are higher on Machias Seal Island than other sites globally and in the Gulf of Maine region, but only for some species. Further detailed investigations are required to determine the cause of this trend.

Internal redistribution of radiolabelled silver among tissues of rainbow trout (Oncorhynchus mykiss) and European eel (Anguilla anguilla)

DEFF Research Database (Denmark)

Hogstrand, C.; Grosell, M.; Wood, C.M.

2003-01-01

chloride water). Contents and concentrations of Ag-110m(l) in tissues and body fluids were then monitored over a 67-day post-exposure period in Ag(I)-free water of the same chloride levels. Changing the speciation of Ag(l) in the water had no effect on the whole body load of Ag-110m(I), but did result......(I) through the 67-day period, whereas the body burden of Ag-110m(I) in eel was reduced to half initial values by day 67. (C) 2002 Elsevier Science B.V. All rights reserved....... in differences in internal distribution. In trout, changing water Ag(I) speciation significantly altered elimination or accumulation of Ag(I) in several body compartments. Notably, trout exposed to AgClaq eliminated Ag-110m(l) from the kidney more quickly than trout exposed to Ag(l) primarily as Ag...

Assessment of mercury contamination in the Bílina River (Czech Republic using indicator fish

Directory of Open Access Journals (Sweden)

Kamila Kružíková

2012-01-01

Full Text Available The aim of the study was to determine mercury content in the muscle of indicator fish and to assess mercury pollution along the Bílina River, which is one of the most important tributaries of the Elbe River. A total of eight sites were chosen on the Bílina River for sampling. Indicator fish chub (Leuciscus cephalus L, roach (Rutilus rutilus L. and brown trout (Salmo trutta m. fario L. in the total numbers of 24, 26 and 27, respectively, were sampled at four locations, since at the remaining sites fish were absent. Mercury concentrations in the muscle of sampled indicator fish were measured using cold vapour atomic absorption spectrometry on an AMA 254 analyser. The highest mercury content (0.12 ± 0.027 mg·kg-1 was found in the muscle of roach at the Ústí nad Labem site and the lowest mercury content (0.04 ± 0.008 mg·kg-1 in the muscle of brown trout from the Březenec (the first upstream site site. A significant difference (P -1 and brown trout (0.04 mg·kg-1 at the Březenec site. The priority of this study was to assess the mercury contamination of the Bílina River because this river flows through a heavy industrial activity in the region (especially production of petrochemicals, agrochemicals, sorbents, plasticizers and textile auxiliaries. Despite the fact that the Bílina is an extensively polluted river, the obtained mercury results were very low and did not exceed the limit of 0.5 mg·kg-1 set by Commission Regulation No. 1881/2006.

Determination of mercury in human tissues after acute poisoning by neutron activation

International Nuclear Information System (INIS)

Rakovic, M.; Glagolicova, A.; Prouza, Z.; Gregora, Z.

1976-01-01

The non-destructive determination of mercury in human tissues after acute poisoning based on the use of a γ-ray spectometer with a Ge(Li) semiconductor detector is described. Samples were irradiated at a thermal neutron flux density of about 10 12 n cm -2 s -1 for 4 hrs. From the results of the preliminary experiments the following conclusions have been drawn. The mercury losses should be negligible when drying of the biological samples at 80 deg C. To irradiate samples for mercury determination is preferable in silica tubes than in polyethylene ones. (T.I.)

Concentration of mercury and selenium in tissues of five cetacean species from Croatian coastal waters

Directory of Open Access Journals (Sweden)

Bilandžić Nina

2015-01-01

Full Text Available Mercury (Hg and selenium (Se concentrations were measured in muscle, liver, kidney, spleen and lung tissues of five cetacean species, three dolphin (Stenella coeruleoalba, Tursiops truncatus and Grampus griseus and two whale species (Balaenoptera physalus and Ziphius cavirostris, stranded along the Croatian coast during the period 1999-2002. Statistically significant differences in Hg concentrations in muscle, spleen and lung, and Se in liver and lung of the different dolphin species were observed. Mercury levels in liver and spleen and Se levels in liver differed between young and adult T. truncatus species. A significant positive correlation between different tissue types for Hg and Se concentrations was observed. In all tissues tested, the lowest Hg and Se concentrations were found in B. physalus. Mercury concentrations were positively correlated with Se in all tissues. The results present one of few studies related to lung and spleen tissues in these mammals, particularly in the Adriatic Sea. Since very little data are available, this research provides new data on concentrations of Hg and Se in five cetacean species from the Adriatic Sea basin.

Mercury monitoring in fish using a non-lethal tissue biopsy method

Science.gov (United States)

Ackerson, J; Schmitt, Christopher J.; McKee, J; Brumbaugh, W. G.

2010-01-01

The occurrence of mercury in fish is well-known and often occurs at levels that warrant restricted consumption by sensitive human populations. Because of this, local wildlife and health agencies have developed monitoring programs to identify the magnitude of fish contamination and changes through time. Monitoring mercury levels in fish typically requires killing fish for removal of a fillet. Recently, researchers have proposed the use of a non-lethal tissue biopsy plug method as a surrogate for analysis of the entire fillet.

Growth type of vertebral centra and the hard tissue observed by microradiography of the rainbow trout

International Nuclear Information System (INIS)

Kubo, Y.; Asano, H.

1987-01-01

To clarify the growth feature and the structure of hard tissue, we studied the vertebral centrum of rainbow trout Salmo gairdneri, using three specimens (BL: 21.0, 29.0 and 40.0cm). We examined the ratio of centrum length to centrum diameter in each vertebral centrum and obtained the value of 0.8-1.0 in most centra. This indicates that the vertebral centra of rainbow trout belong to the so-called equivalent type. The hard tissue was observed by microradiography, with the longitudinal and cross sections (about 100 μm)cut through the center of notochordal pore. The microradiograph of thin section of centrurn differentiated serially and changed in pattern, but it is clear to sustain the specific characteristics. In longitudinal sections, the V-shaped part of bone was composed of structure like compact bone through the length of vertebral column. In cross sections, the notochordal pore was enclosed by the radial trabecular bones, the arrangement gradually turning toward the posterior centra like paired fans set opposite each other laterally

Fate of Tetracapsuloides bryosalmonae (Myxozoa) after infection of brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss.

Science.gov (United States)

Kumar, Gokhlesh; Abd-Elfattah, Ahmed; Saleh, Mona; El-Matbouli, Mansour

2013-11-25

Tetracapsuloides bryosalmonae (Myxozoa) is the causative agent of proliferative kidney disease in salmonids. We assessed differences in intensity of T. bryosalmonae infection between brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss from the clinical phase of infection onwards. Specific pathogen-free fish were exposed to T. bryosalmonae spores under controlled laboratory conditions and sampled at 6, 8, 10, 12, 14, and 17 wk post exposure (wpe), and the transmission of T. bryosalmonae from infected fish to the bryozoan Fredericella sultana was observed. Parasite load was determined in fish kidneys by quantitative real-time PCR (qRT-PCR), and parasite stages were detected in kidney, liver, and spleen tissues at different time points by immunohistochemistry. T. bryosalmonae was successfully transmitted from infected brown trout to F. sultana colonies but not from infected rainbow trout. Body length and weight of infected brown trout did not differ significantly from control brown trout during all time points, while length and weight of infected rainbow trout differed significantly compared to controls from 10 to 17 wpe. qRT-PCR revealed that parasite load was significantly higher in kidneys of brown trout compared with rainbow trout. Immunohistochemistry showed high numbers of intra-luminal stages (sporogonic stages) in kidneys of brown trout with low numbers of pre-sporogonic stages. Sporogonic stages were not seen in kidneys of rainbow trout; only high numbers of pre-sporogonic stages were detected. Numbers of pre-sporogonic stages were low in the spleen and liver of brown trout but high in rainbow trout. These data confirmed that there are differences in the development and infection progress of T. bryosalmonae between brown trout and rainbow trout.

Fate of Tetracapsuloides bryosalmonae (Myxozoa) after infection of brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss

Science.gov (United States)

Kumar, Gokhlesh; Abd-Elfattah, Ahmed; Saleh, Mona; El-Matbouli, Mansour

2014-01-01

Tetracapsuloides bryosalmonae (Myxozoa) is the causative agent of proliferative kidney disease in salmonids. We assessed differences in intensity of T. bryosalmonae infection between brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss from the clinical phase of infection onwards. Specific pathogen-free fish were exposed to T. bryosalmonae spores under controlled laboratory conditions and sampled at 6, 8, 10, 12, 14, and 17 wk post exposure (wpe), and the transmission of T. bryosalmonae from infected fish to the bryozoan Fredericella sultana was observed. Parasite load was determined in fish kidneys by quantitative real-time PCR (qRT-PCR), and parasite stages were detected in kidney, liver, and spleen tissues at different time points by immunohistochemistry. T. bryosalmonae was successfully transmitted from infected brown trout to F. sultana colonies but not from infected rainbow trout. Body length and weight of infected brown trout did not differ significantly from control brown trout during all time points, while length and weight of infected rainbow trout differed significantly compared to controls from 10 to 17 wpe. qRT-PCR revealed that parasite load was significantly higher in kidneys of brown trout compared with rainbow trout. Immunohistochemistry showed high numbers of intra-luminal stages (sporogonic stages) in kidneys of brown trout with low numbers of pre-sporogonic stages. Sporogonic stages were not seen in kidneys of rainbow trout; only high numbers of pre-sporogonic stages were detected. Numbers of pre-sporogonic stages were low in the spleen and liver of brown trout but high in rainbow trout. These data confirmed that there are differences in the development and infection progress of T. bryosalmonae between brown trout and rainbow trout. PMID:24270019

Detection of virus level in tissues of rainbow trout, Oncoryhinchus mykiss in clinical stage of viral hemorrhagic septicemia

DEFF Research Database (Denmark)

Ghiasi, Farzad; Olesen, Niels Jørgen

2014-01-01

tanks containing 70 fish. Group one was considered as control and group two infected by bath challenge with 103 TCID50 ml-1 of a VHS virus strain serologically similar to reference strain F1 with high pathogenicity in rainbow trout. At days 12, 13 and 14 post infection the organs including kidney...... liver, gill, pyloric caeca and skin showed the lowest with brain and spleen lying in between. These results point out that the significant levels of VHS virus found in rainbow trout tissues are relevant for the biosecurity in VHS-free areas mainly when fish are displayed and retained as whole fish....

The Effects on Antioxidant Enzyme Systems in Rat Brain Tissues of Lead Nitrate and Mercury Chloride

OpenAIRE

Baş, Hatice; Kalender, Suna; Karaboduk, Hatice; Apaydın, Fatma

2014-01-01

The present study was undertaken to evaluate the effects of lead nitrate and mercury chloride in brain tissues of Wistar rats. Mercury chloride (0.02 mg/kg bw) and lead nitrate (45 mg/kg bw) were administered orally for 28 days rats. The mercury chloride and lead nitrate treated animals were exhibited a significant inhibition of superoxide dismutase, catalase, glutation peroxidase and glutathione-S-transferase activities and increasing of malondialdehyde levels. In our present study mercury c...

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.

Quantification of total mercury in liver and heart tissue of Harbor Seals (Phoca vitulina) from Alaska USA

International Nuclear Information System (INIS)

Marino, Kady B.; Hoover-Miller, Anne; Conlon, Suzanne; Prewitt, Jill; O'Shea, Stephen K.

2011-01-01

This study quantified the Hg levels in the liver (n=98) and heart (n=43) tissues of Harbor Seals (Phoca vitulina) (n=102) harvested from Prince William Sound and Kodiak Island Alaska. Mercury tissue dry weight (dw) concentrations in the liver ranged from 1.7 to 393 ppm dw, and in the heart from 0.19 to 4.99 ppm dw. Results of this study indicate liver and heart tissues' Hg ppm dw concentrations significantly increase with age. Male Harbor Seals bioaccumulated Hg in both their liver and heart tissues at a significantly faster rate than females. The liver Hg bioaccumulation rates between the harvest locations Kodiak Island and Prince William Sound were not found to be significantly different. On adsorption Hg is transported throughout the Harbor Seal's body with the partition coefficient higher for the liver than the heart. No significant differences in the bio-distribution (liver:heart Hg ppm dw ratios (n=38)) values were found with respect to either age, sex or geographic harvest location. In this study the age at which Hg liver and heart bioaccumulation levels become significantly distinct in male and female Harbor Seals were identified through a Tukey's analysis. Of notably concern to human health was a male Harbor Seal's liver tissue harvested from Kodiak Island region. Mercury accumulation in this sample tissue was determined through a Q-test to be an outlier, having far higher Hg concentrarion (liver 392 Hg ppm dw) than the general population sampled. - Highlights: ► Mercury accumulation in the liver and heart of seals exceed food safety guidelines. ► Accumulation rate is greater in males than females with age. ► Liver mercury accumulation is greater than in the heart tissues. ► Mercury determination by USA EPA Method 7473 using thermal decomposition.

Mercury, Fatty Acids Content and Lipid Quality Indexes in Muscles of Freshwater and Marine Fish on the Polish Market. Risk Assessment of Fish Consumption.

Science.gov (United States)

Łuczyńska, Joanna; Paszczyk, Beata; Nowosad, Joanna; Łuczyński, Marek Jan

2017-09-25

Mercury content and fatty acids in muscles of Perca fluviatilis L. (European perch), Leuciscus idus L. (ide), Cyprinus carpio L. (European or common carp), Oncorhynchus mykiss Walb. (rainbow trout), Platichthys flesus L. (European flounder). and Clupea harengus L. (bream) from the Polish market were investigated. The total mercury was processed with AAS. The fatty acids were analyzed by gas chromatography. The concentration of mercury in muscles varied from 0.006 to 0.138 mg/kg and decreased as follows: perch ≈ ide > flounder > herring ≈ bream ≈ rainbow trout > carp ( p ≤ 0.05). There were only significant positive correlations between body weight and mercury content in muscle tissue of carp (r = 0.878), flounder (r = 0.925) and herring (r = 0.982) ( p ≤ 0.05). The atherogenic index (AI), thrombogenicity index (TI) and flesh-lipid quality index (FLQ) were calculated as follows 0.33-0.70 (IA), 0.16-0.31 (IT) and 13.01-33.22 (FLQ). Hypocholesterolemic (OFA) and hypercholesterolemic fatty acids (DFA) in muscles of fish ranged from 18.26 to 23.01 and from 73.91 to 78.46, respectively. In most cases, there were not significant correlations between size (body weight and total length) and fatty acids in the muscles of the examined fish ( p > 0.05). The Target Hazard Quotient (THQ) values were below 1, which shows that there is no non-carcinogenic health risk to the consumer by consuming the examined fish.

Mercury, Fatty Acids Content and Lipid Quality Indexes in Muscles of Freshwater and Marine Fish on the Polish Market. Risk Assessment of Fish Consumption

Directory of Open Access Journals (Sweden)

Joanna Łuczyńska

2017-09-01

Full Text Available Mercury content and fatty acids in muscles of Perca fluviatilis L. (European perch, Leuciscus idus L. (ide, Cyprinus carpio L. (European or common carp, Oncorhynchus mykiss Walb. (rainbow trout, Platichthys flesus L. (European flounder. and Clupea harengus L. (bream from the Polish market were investigated. The total mercury was processed with AAS. The fatty acids were analyzed by gas chromatography. The concentration of mercury in muscles varied from 0.006 to 0.138 mg/kg and decreased as follows: perch ≈ ide > flounder > herring ≈ bream ≈ rainbow trout > carp (p ≤ 0.05. There were only significant positive correlations between body weight and mercury content in muscle tissue of carp (r = 0.878, flounder (r = 0.925 and herring (r = 0.982 (p ≤ 0.05. The atherogenic index (AI, thrombogenicity index (TI and flesh-lipid quality index (FLQ were calculated as follows 0.33–0.70 (IA, 0.16–0.31 (IT and 13.01–33.22 (FLQ. Hypocholesterolemic (OFA and hypercholesterolemic fatty acids (DFA in muscles of fish ranged from 18.26 to 23.01 and from 73.91 to 78.46, respectively. In most cases, there were not significant correlations between size (body weight and total length and fatty acids in the muscles of the examined fish (p > 0.05. The Target Hazard Quotient (THQ values were below 1, which shows that there is no non-carcinogenic health risk to the consumer by consuming the examined fish.

Preliminary study of selenium and mercury distribution in some porcine tissues and their subcellular fractions by NAA and HG-AFS

International Nuclear Information System (INIS)

Jiujiang Zhao; Chunying Chen; Peiqun Zhang; Zhifang Chai

2004-01-01

Selenium and mercury distribution in porcine tissues and their subcellular fractions from a mercury-polluted area of Guizhou Province and from a not mercury-exposed area of Beijing in China have been studied with neutron activation analysis and hydride generation-atomic fluorescence spectrometry. Both the selenium and mercury levels are higher in Guizhou porcine tissues and their subcellular fractions than those in Beijing. These two elements are highly enriched in kidney and liver of Guizhou pig, while selenium is only enriched in the kidney of Beijing pig. Exposure of mercury may result in redistribution of Se and Hg in vivo. The Hg/Se molar ratio of the subcellular fractions is very low in the case of relatively low mercury level and gradually reaches to a high constant value with increasing level of mercury, which implies that selenium and mercury may form some special complexes in the organisms. (author)

Ontogenetic profile of innate immune related genes and their tissue-specific expression in brown trout, Salmo trutta (Linnaeus, 1758).

Science.gov (United States)

Cecchini, Stefano; Paciolla, Mariateresa; Biffali, Elio; Borra, Marco; Ursini, Matilde V; Lioi, Maria B

2013-09-01

The innate immune system is a fundamental defense weapon of fish, especially during early stages of development when acquired immunity is still far from being completely developed. The present study aims at looking into ontogeny of innate immune system in the brown trout, Salmo trutta, using RT-PCR based approach. Total RNA extracted from unfertilized and fertilized eggs and hatchlings at 0, 1 h and 1, 2, 3, 4, 5, 6, 7 weeks post-fertilization was subjected to RT-PCR using self-designed primers to amplify some innate immune relevant genes (TNF-α, IL-1β, TGF-β and lysozyme c-type). The constitutive expression of β-actin was detected in all developmental stages. IL-1β and TNF-α transcripts were detected from 4 week post-fertilization onwards, whereas TGF-β transcript was detected only from 7 week post-fertilization onwards. Lysozyme c-type transcript was detected early from unfertilized egg stage onwards. Similarly, tissues such as muscle, ovary, heart, brain, gill, testis, liver, intestine, spleen, skin, posterior kidney, anterior kidney and blood collected from adult brown trout were subjected to detection of all selected genes by RT-PCR. TNF-α and lysozyme c-type transcripts were expressed in all tissues. IL-1β and TGF-β transcripts were expressed in all tissues except for the brain and liver, respectively. Taken together, our results show a spatial-temporal expression of some key innate immune-related genes, improving the basic knowledge of the function of innate immune system at early stage of brown trout. Copyright © 2013 Elsevier Ltd. All rights reserved.

Robust microwave-assisted extraction protocol for determination of total mercury and methylmercury in fish tissues

Energy Technology Data Exchange (ETDEWEB)

Reyes, L. Hinojosa; Rahman, G.M. Mizanur [Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282 (United States); Kingston, H.M. Skip [Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282 (United States)], E-mail: kingston@duq.edu

2009-01-12

A rapid and efficient closed vessel microwave-assisted extraction (MAE) method based on acidic leaching was developed and optimized for the extraction of total mercury (Hg), inorganic mercury (Hg{sup 2+}) and methylmercury (CH{sub 3}Hg{sup +}) from fish tissues. The quantitative extraction of total Hg and mercury species from biological samples was achieved by using 5 mol L{sup -1} HCl and 0.25 mol L{sup -1} NaCl during 10 min at 60 deg. C. Total Hg content was determined using inductively coupled plasma mass spectrometry (ICP-MS). Mercury species were measured by liquid chromatography hyphenated with inductively coupled plasma mass spectrometry (LC-ICP-MS). The method was validated using biological certified reference materials ERM-CE464, DOLT-3, and NIST SRM-1946. The analytical results were in good agreement with the certified reference values of total Hg and CH{sub 3}Hg{sup +} at a 95% confidence level. Further, accuracy validation using speciated isotope-dilution mass spectrometry (SIDMS, as described in the EPA Method 6800) was carried out. SIDMS was also applied to study and correct for unwanted species transformation reactions during and/or after sample preparation steps. For the studied reference materials, no statistically significant transformation between mercury species was observed during the extraction and determination procedures. The proposed method was successfully applied to fish tissues with good agreement between SIDMS results and external calibration (EC) results. Interspecies transformations in fish tissues were slightly higher than certified reference materials due to differences in matrix composition. Depending on the type of fish tissue, up to 10.24% of Hg{sup 2+} was methylated and up to 1.75% of CH{sub 3}Hg{sup +} was demethylated to Hg{sup 2+}.

Oxidative stress biomarkers in different tissues of rainbow trout (Oncorhynchus mykiss exposed to Disinfectant-CIP formulated with peracetic acid and hydrogen peroxide

Directory of Open Access Journals (Sweden)

Tkachenko Halyna

2014-09-01

Full Text Available The aim of study was to determine the effects of exposure to the product DEZYNFEKTANT-CIP (Eng. - Disinfectant-CIP, which is formulated with peracetic acid and hydrogen peroxide, on oxidative stress biomarkers (lipid peroxidation (LPO levels and the carbonyl content of oxidatively modified proteins and antioxidant defenses (superoxide dismutase (SOD, catalase (CAT, glutathione reductase (GR, glutathione peroxidase (GPx, total antioxidant capacity in muscle, gill, hepatic, and cardiac tissues of rainbow trout, Oncorhynchus mykiss (Walbaum. LPO and carbonyl contents changed with tissue type. Exposure to Disinfectant-CIP led to a significant decrease in LPO in muscle tissues and carbonyl content in muscle and gill tissues. The inhibition of SOD and CAT activity in muscle, hepatic, and cardiac tissues was observed probably because of increased oxidative stress during disinfection; however, hepatic and cardiac GPx activity increased in an attempt to counteract oxidative stress. We suggest that oxidative stress during the oxidation of peracetic acid and hydrogen peroxide could be counteracted by the antioxidant system in trout tissues. Correlative analysis between oxidative stress biomarkers and antioxidant defense confirms the pivotal role of SOD and CAT against CIP-induced oxidative stress

Determination of mercury by cold-vapor technique in several tissues of treated American red crayfish (Procambarus clarkii)

Energy Technology Data Exchange (ETDEWEB)

Del Ramo, J.; Pastor, A.; Diaz-Mayans, J.; Medina, J.; Torreblanca, A.

1988-01-01

Adult intermolt specimens of American red crayfish (Procambarus clarkii) collected from Lake Albufera (Valencia, Spain), were exposed to mercury during 96 h. The Hg-concentrations used were 50, 100, and 250 ..mu..g Hg/l as Cl/sub 2/Hg. The content of mercury in muscle, midgut gland, antennal glands and gills was investigated. Determinations of mercury were made by cold-vapor technique and AAS. The mercury levels in all examined tissues increased significantly with increasing Hg-concentration in the water.

Draft Genome Sequence of a Picorna-Like Virus Associated with Gill Tissue in Clinically Normal Brook Trout, Salvelinus fontinalis

OpenAIRE

Iwanowicz, Luke R.; Iwanowicz, Deborah D.; Adams, Cynthia R.; Galbraith, Heather; Aunins, Aaron; Cornman, Robert S.

2017-01-01

ABSTRACT Here, we report a draft genome sequence of a picorna-like virus associated with brook trout, Salvelinus fontinalis, gill tissue. The draft genome comprises 8,681 nucleotides, excluding the poly(A) tract, and contains two open reading frames. It is most similar to picorna-like viruses that infect invertebrates.

Draft Genome Sequence of a Picorna-Like Virus Associated with Gill Tissue in Clinically Normal Brook Trout, Salvelinus fontinalis.

Science.gov (United States)

Iwanowicz, Luke R; Iwanowicz, Deborah D; Adams, Cynthia R; Galbraith, Heather; Aunins, Aaron; Cornman, Robert S

2017-10-12

Here, we report a draft genome sequence of a picorna-like virus associated with brook trout, Salvelinus fontinalis , gill tissue. The draft genome comprises 8,681 nucleotides, excluding the poly(A) tract, and contains two open reading frames. It is most similar to picorna-like viruses that infect invertebrates.

Mercury bioaccumulation in fish in a region affected by historic gold mining; the South Yuba River, Deer Creek, and Bear River watersheds, California, 1999

Science.gov (United States)

May, Jason T.; Hothem, Roger L.; Alpers, Charles N.; Law, Matthew A.

2000-01-01

Mercury that was used historically for gold recovery in mining areas of the Sierra Nevada continues to enter local and downstream water bodies, including the Sacramento Delta and the San Francisco Bay of northern California. Methylmercury is of particular concern because it is the most prevalent form of mercury in fish and is a potent neurotoxin that bioaccumulates at successive trophic levels within food webs. In April 1999, the U.S. Geological Survey, in cooperation with several other agencies the Forest Service (U.S. Department of Agriculture), the Bureau of Land Management, the U.S. Environmental Protection Agency, the California State Water Resources Control Board, and the Nevada County Resource Conservation District began a pilot investigation to characterize the occurrence and distribution of mercury in water, sediment, and biota in the South Yuba River, Deer Creek, and Bear River watersheds of California. Biological samples consisted of semi-aquatic and aquatic insects, amphibians, bird eggs, and fish. Fish were collected from 5 reservoirs and 14 stream sites during August through October 1999 to assess the distribution of mercury in these watersheds. Fish that were collected from reservoirs included top trophic level predators (black basses, Micropterus spp.) intermediate trophic level predators [sunfish (blue gill, Lepomis macrochirus; green sunfish, Lepomis cyanellus; and black crappie, Poxomis nigromaculatus)] and benthic omnivores (channel catfish, Ictularus punctatus). At stream sites, the species collected were upper trophic level salmonids (brown trout, Salmo trutta) and upper-to-intermediate trophic level salmonids (rainbow trout, Oncorhynchus mykiss). Boneless and skinless fillet portions from 161 fish were analyzed for total mercury; 131 samples were individual fish, and the remaining 30 fish were combined into 10 composite samples of three fish each of the same species and size class. Mercury concentrations in samples of black basses

Glucose homeostasis in rainbow trout fed a high-carbohydrate diet: metformin and insulin interact in a tissue-dependent manner.

Science.gov (United States)

Polakof, S; Moon, T W; Aguirre, P; Skiba-Cassy, S; Panserat, S

2011-01-01

Carnivorous fish species such as the rainbow trout (Oncorhynchus mykiss) are considered to be "glucose intolerant" because of the prolonged hyperglycemia experienced after intake of a carbohydrate-enriched meal. In the present study, we use this species to study glucose homeostasis in fish chronically infused with the hypoglycemic agents, insulin, and metformin, and fed with a high proportion of carbohydrates (30%). We analyzed liver, skeletal muscle, and white adipose tissue (WAT), which are insulin- and metformin-specific targets at both the biochemical and molecular levels. Trout infused with the combination of insulin and metformin can effectively utilize dietary glucose at the liver, resulting in lowered glycemia, increased insulin sensitivity, and glucose storage capacity, combined with reduced glucose output. However, in both WAT and skeletal muscle, we observed decreased insulin sensitivity with the combined insulin + metformin treatment, resulting in the absence of changes at the metabolic level in the skeletal muscle and an increased potential for glucose uptake and storage in the WAT. Thus, the poor utilization by rainbow trout of a diet with a high proportion of carbohydrate can at least be partially improved by a combined treatment with insulin and metformin, and the glucose intolerance observed in this species could be, in part, due to some of the downstream components of the insulin and metformin signaling pathways. However, the predominant effects of metformin treatment on the action of insulin in these three tissues thought to be involved in glucose homeostasis remain exclusive in this species.

POSSIBLE RAMIFICATIONS OF HIGHER MERCURY CONCENTRATIONS IN FILLET TISSUE OF SKINNIER FISH

Science.gov (United States)

Mercury concentrations were found to be statistically higher in the fillet tissue of the skinnier individuals of a fish species (striped bass) that was experiencing starvation when collected from Lake Mead, which is located on the Arizona-Nevada border. This is considered a conse...

Cytochemical demonstration of mercury deposits in trout liver and kidney following methyl mercury intoxication: differentiation of two mercury pools by selenium

DEFF Research Database (Denmark)

Baatrup, E; Danscher, G

1988-01-01

and the selected organs were determined by measuring the uptake of 203Hg-labeled MeHg. Spleen, liver, and kidney had the highest concentrations after both experimental periods, while the largest relative increases were found in brain, muscle, and kidney. The subcellular distribution of mercury accumulations...... was demonstrated cytochemically in liver and kidney using the silver enhancement method by which accumulations of mercury-sulfides and/or mercury-selenides are made visible for light and electron microscopy. When sections prepared from the liver and kidney from fish, injected with selenium 2 hr prior to being...... pronounced in the kidney. The HgSe pool, supposed to represent methyl mercury, was shown by the presence of silver deposits at new locations as well as by an increase in the amount of deposits within lysosomes. The new locations included (1) secretory-like vesicles and the bile canaliculi of the liver...

Identification of the thiamin pyrophosphokinase gene in rainbow trout: Characteristic structure and expression of seven splice variants in tissues and cell lines and during embryo development

Science.gov (United States)

Yuge, Shinya; Richter, Catherine A.; Wright-Osment, Maureen K.; Nicks, Diane; Saloka, Stephanie K.; Tillitt, Donald E.; Li, Weiming

2012-01-01

Thiamin pyrophosphokinase (TPK) converts thiamin to its active form, thiamin diphosphate. In humans, TPK expression is down-regulated in some thiamin deficiency related syndrome, and enhanced during pregnancy. Rainbow trout are also vulnerable to thiamin deficiency in wild life and are useful models for thiamin metabolism research. We identified the tpk gene transcript including seven splice variants in the rainbow trout. Almost all cell lines and tissues examined showed co-expression of several tpk splice variants including a potentially major one at both mRNA and protein levels. However, relative to other tissues, the longest variant mRNA expression was predominant in the ovary and abundant in embryos. During embryogenesis, total tpk transcripts increased abruptly in early development, and decreased to about half of the peak shortly after hatching. In rainbow trout, the tpk transcript complex is ubiquitously expressed for all tissues and cells examined, and its increase in expression could be important in the early-middle embryonic stages. Moreover, decimated tpk expression in a hepatoma cell line relative to hepatic and gonadal cell lines appears to be consistent with previously reported down-regulation of thiamin metabolism in cancer.

Characterization of elements of the kallikrein-kinin system in rainbow trout (Salmo gairdneri)

International Nuclear Information System (INIS)

Lipke, D.W.

1988-01-01

Elements of kallikrein-kinin system (KKS) are found in anamniotic vertebrates, however, research has failed to substantiate the presence of a KKS in these animals. This research was conducted to verify the presence of elements of the KKS in rainbow trout. Trout branchial angiotensin-converting enzyme (ACE, kininase II) was similar to mammalian ACE in many physical, chemical and kinetic parameters. Angiotensin-converting enzyme-like activity (ACELA) was also demonstrated in the most primitive vertebrates. ACELA was consistently found in vertebrate respiratory tissues and was prevalent in salt and water exchanging organs. 3 H-bradykinin, perfused through the trout gill was not metabolized, as demonstrated by high voltage paper electrophoresis. However, trout gills extracted and retained approximately 40% of the 3 H-bradykinin perfused into the branchial vasculature. Gill tissue homogenates metabolized both 3 H-bradykinin and the vasoactive substance produced by incubating trout plasma with glandular kallikrein

Detection of free and covalently bound microcystins in different tissues (liver, intestines, gills, and muscles) of rainbow trout (Oncorhynchus mykiss) by liquid chromatography–tandem mass spectrometry: Method characterization

International Nuclear Information System (INIS)

Cadel-Six, Sabrina; Moyenga, David; Magny, Stéphanie; Trotereau, Sophie; Edery, Marc; Krys, Sophie

2014-01-01

So far only a few publications have explored the development of extraction methods of cyanotoxin extracted from complex matrices. With regard to cyanobacterial microcystins (MCs), the data on the contamination of the flesh of aquatic organisms is hard to compare and very limited due to the lack of validated methods. In recent years, evidence that both free and bound fractions of toxin are found in these tissues has highlighted the need to develop effective methods of quantification. Several techniques do exist, but only the Lemieux oxidation has so far been used to investigate complex tissue matrices. In this study, protocols based on the Lemieux approach were adapted for the quantitative chemical analysis of free MC-LR and MMPB derived from bound toxin in the tissues of juvenile trout gavaged with MC-LR. Afterwards, the NF V03 110 guideline was used to characterize the protocols elaborated and evaluate their effectiveness. -- Highlights: • We adapted the quantitative chemical analysis of free and total MC for the tissues of trout. • We characterize with the NF V03 110 guideline the protocols for free MC-LR and MMPB. • We quantify the free MC-LR and MMPB in the tissues of trout gavaged with MC-LR. -- We develop and characterize with the guideline NF V03 110 the protocols for the extraction and quantification of the free and total MC for different matrices

Identification and tissue distribution of mRNAs encoding salmon-type calcitonins-IV and -V in the rainbow trout.

Science.gov (United States)

Hidaka, Yoshie; Suzuki, Masakazu

2004-06-01

Four types of calcitonin are produced in salmonid fish, although their functional diversity is almost unknown. To explore the significance of these isoforms, we have characterized salmon-type calcitonin (sCT) mRNAs in the rainbow trout (Oncorhynchus mykiss), and examined their tissue distribution. In addition to the previously isolated sCT-I cDNAs, two new forms of sCT cDNA were cloned from the ultimobranchial gland, and one of them (sCT-IV cDNA) was predicted to encode an N-terminal peptide of 80 amino acid residues, a putative cleavage site Lys-Arg, sCT-IV, a cleavage and amidation sequence Gly-Lys-Lys-Arg, and a C-terminal peptide of 18 amino acids. The sCT-IV precursor was 78% identical with the rainbow trout sCT-I precursors. The other cloned cDNA encoded a precursor for a novel CT, sCT-V. The sCT-V peptide was different from sCT-IV by only one amino acid residue: Val at position 8 in the latter was replaced by Met. The sCT-V precursor had 80 and 90% identity with the sCT-I and -IV precursors respectively. No cDNA clones were obtained for sCTs-II or -III.Tissue distribution of sCT-I, -IV and -V mRNAs was examined by RT-PCR and specific cleavage with restriction enzymes. An amplified fragment from sCT-I mRNA was detected not only in the ultimobranchial gland, but also in the gills, testis and ovary. RT-PCR analysis coupled to restriction digestion further revealed that sCT-IV mRNA was expressed in both the testis and the ultimobranchial gland. The expression sites of sCT-IV mRNA were localized to the Leydig cells of the testis and to the parenchymal cells of the ultimobranchial gland, by in situ hybridization histochemistry. Although the amino acid sequence of sCT-V peptide was nearly the same as that of sCT-IV, the sCT-V gene showed a much wider pattern of expression: the band amplified by RT-PCR was detected in all the tissues examined except the kidney, gills and blood cells. The sCT-V mRNA was shown to be localized in the parenchymal cells of the

Water striders (family Gerridae): mercury sentinels in small freshwater ecosystems

International Nuclear Information System (INIS)

Jardine, Timothy D.; Al, Tom A.; MacQuarrie, Kerry T.B.; Ritchie, Charles D.; Arp, Paul A.; Maprani, Antu; Cunjak, Richard A.

2005-01-01

To circumvent some of the previous limitations associated with contaminant-monitoring programs, we tested the suitability of the water strider (Hemiptera: Gerridae) as a mercury sentinel by comparing total mercury concentrations in water striders and brook trout (Salvelinus fontinalis) from a variety of stream sites in New Brunswick, Canada. There was a strong association between the two variables across sites (r 2 = 0.81, P < 0.001) in systems where both atmospheric deposition and a point source (an abandoned gold mine) were likely contributing to ambient mercury levels. In a small stream draining the gold mine tailings pile, water striders had mercury concentrations an order of magnitude higher than those from reference locations. Temporal variation at three southern New Brunswick stream sites was non-significant. These results suggest that water strider mercury levels accurately quantify food chain entry of the element. The use of sentinel species holds great potential for expanding contaminant-monitoring programs. - Water striders accurately reflect the entry of mercury in food chains of small freshwater systems

Infectious pancreatic necrosis the trout farmers' dilemma

Science.gov (United States)

Parisot, T.J.

1965-01-01

Induction of the innate immune pathways is critical for early anti-viral defense but there is limited understanding of how teleost fish recognize viral molecules and activate these pathways. In mammals, Toll-like receptors (TLR) 7 and 8 bind single-stranded RNA of viral origin and are activated by synthetic anti-viral imidazoquinoline compounds. Herein, we identify and describe the rainbow trout (Oncorhynchus mykiss) TLR7 and TLR8 gene orthologs and their mRNA expression. Two TLR7/8 loci were identified from a rainbow trout bacterial artificial chromosome (BAC) library using DNA fingerprinting and genetic linkage analyses. Direct sequencing of two representative BACs revealed intact omTLR7and omTLR8a1 open reading frames (ORFs) located on chromosome 3 and a second locus on chromosome 22 that contains an omTLR8a2 ORF and a putative TLR7pseudogene. We used the omTLR8a1/2 nomenclature for the two trout TLR8 genes as phylogenetic analysis revealed that they and all the other teleost TLR8 genes sequenced to date are similar to the zebrafish TLR8a, but are distinct from the zebrafish TLR8b. The duplicated trout loci exhibit conserved synteny with other fish genomes extending beyond the tandem of TLR7/8 genes. The trout TLR7 and 8a1/2 genes are composed of a single large exon similar to all other described TLR7/8 genes. The omTLR7 ORF is predicted to encode a 1049 amino acid (aa) protein with 84% similarity to the Fugu TLR7and a conserved pattern of predicted leucine-rich repeats (LRR). The omTLR8a1 andomTLR8a2 are predicted to encode 1035- and 1034-aa proteins, respectively, and have 86% similarity to each other. omTLR8a1 is likely the ortholog of the only Atlantic salmonTLR8 gene described to date as they have 95% aa sequence similarity. The tissue expression profiles of omTLR7, omTLR8a1 and omTLR8a2 in healthy trout were highest in spleen tissue followed by anterior and then posterior kidney tissues. Rainbow trout anterior kidney leukocytes produced elevated levels of

Below a Historic Mercury Mine: Non-linear Patterns of Mercury Bioaccumulation in Aquatic Organisms

Science.gov (United States)

Haas, J.; Ichikawa, G.; Ode, P.; Salsbery, D.; Abel, J.

2001-12-01

Unlike most heavy metals, mercury is capable of bioaccumulating in aquatic food-chains, primarily because it is methylated by bacteria in sediment to the more toxic methylmercury form. Mercury concentrations in a number of riparian systems in California are highly elevated as a result of historic mining activities. These activities included both the mining of cinnabar in the coastal ranges to recover elemental mercury and the use of elemental mercury in the gold fields of the Sierra Nevada Mountains. The most productive mercury mining area was the New Almaden District, now a county park, located in the Guadalupe River drainage of Santa Clara County, where cinnabar was mined and retorted for over 100 years. As a consequence, riparian systems in several subwatersheds of the Guadalupe River drainage are contaminated with total mercury concentrations that exceed state hazardous waste criteria. Mercury concentrations in fish tissue frequently exceed human health guidelines. However, the potential ecological effects of these elevated mercury concentrations have not been thoroughly evaluated. One difficulty is in extrapolating sediment concentrations to fish tissue concentrations without accounting for physical and biological processes that determine bioaccumulation patterns. Many processes, such as methylation and demethylation of mercury by bacteria, assimilation efficiency in invertebrates, and metabolic rates in fish, are nonlinear, a factor that often confounds attempts to evaluate the effects of mercury contamination on aquatic food webs. Sediment, benthic macroinvertebrate, and fish tissue samples were collected in 1998 from the Guadalupe River drainage in Santa Clara County at 13 sites upstream and downstream from the historic mining district. Sediment and macroinvertebrate samples were analyzed for total mercury and methylmercury. Fish samples were analyzed for total mercury as whole bodies, composited by species and size. While linear correlations of sediment

Determination of the exposure parameters that maximise the concentrations of the anaesthetic/sedative eugenol in rainbow trout (Oncorhynchus mykiss) skin-on fillet tissue

Science.gov (United States)

Meinertz, Jeffery R.; Porcher, Scott T.; Smerud, Justin R.

2014-01-01

Studies were conducted to determine the anaesthetic/sedative concentrations and durations that would maximize anaesthetic/sedative residue concentrations in rainbow trout (Oncorhynchus mykiss) skin-on fillet tissue. Rainbow trout (167–404 g) were exposed to 50 mg l−1 AQUI-S® 20E (10% active ingredient, eugenol) in 17°C freshwater for durations up to 1440 min, 100 and 250 mg l−1 AQUI-S® 20E for durations up to 240 min, and 500 and 1000 mg l−1 AQUI-S® 20E for durations up to 90 min. Fish exposed to 100 mg l−1 AQUI-S® 20E for durations of 30, 60, 120 and 240 min had the greatest eugenol concentrations in the fillet tissue, 50, 58, 54 and 62 µg g−1, respectively. All other exposure concentrations and durations resulted in significantly lower eugenol concentrations, i.e. all −1.

Mercury Exposure: Protein Biomarkers of Mercury Exposure in Jaraqui Fish from the Amazon Region.

Science.gov (United States)

Vieira, José Cavalcante Souza; Braga, Camila Pereira; de Oliveira, Grasieli; Padilha, Cilene do Carmo Federici; de Moraes, Paula Martin; Zara, Luiz Fabricio; Leite, Aline de Lima; Buzalaf, Marília Afonso Rabelo; Padilha, Pedro de Magalhães

2018-05-01

This study presents data on the extraction and characterization of proteins associated with mercury in the muscle and liver tissues of jaraqui (Semaprochilodus spp.) from the Madeira River in the Brazilian Amazon. Protein fractionation was carried out by two-dimensional electrophoresis (2D-PAGE). Mercury determination in tissues, pellets, and protein spots was performed by graphite furnace atomic absorption spectrometry (GFAAS). Proteins in the spots that showed mercury were characterized by electrospray ionization tandem mass spectrometry (ESI-MS/MS). The highest mercury concentrations were found in liver tissues and pellets (426 ± 6 and 277 ± 4 μg kg -1 ), followed by muscle tissues and pellets (132 ± 4 and 86 ± 1 μg kg -1 , respectively). Mercury quantification in the protein spots allowed us to propose stoichiometric ratios in the range of 1-4 mercury atoms per molecule of protein in the protein spots. The proteins characterized in the analysis by ESI-MS/MS were keratin, type II cytoskeletal 8, parvalbumin beta, parvalbumin-2, ubiquitin-40S ribosomal S27a, 39S ribosomal protein L36 mitochondrial, hemoglobin subunit beta, and hemoglobin subunit beta-A/B. The results suggest that proteins such as ubiquitin-40S ribosomal protein S27a, which have specific domains, possibly zinc finger, can be used as biomarkers of mercury, whereas mercury and zinc present characteristics of soft acids.

The sexually dimorphic adipose fin is an androgen target tissue in the brown trout (Salmo trutta fario).

Science.gov (United States)

Hisar, Olcay; Sönmez, Adem Yavuz; Hisar, Şükriye Aras; Budak, Harun; Gültepe, Nejdet

2013-04-01

An investigation has been described on the relationship of body length, age and sex with adipose fin length and the number of androgen receptor (AR)-containing cells in the adipose fin as a secondary sexual characteristic for brown trout (Salmo trutta fario). Firstly, body and adipose fin lengths of 2- to 5-year-old brown trout were measured. Thereafter, these fish were killed by decapitation, then their sexes were determined, and adipose fins were excised. The cellular bases of AR binding activities in the adipose fins were analyzed with an antibody against human/rat AR peptide. Immunocytochemistry and western blotting techniques were performed with this antibody. Analysis of morphological measurements indicated that body length and age had a linear relationship with adipose fin length. The coefficients of determination for the body length and age were 0.92 and 0.85 in the male fish and 0.76 and 0.73 in the female fish against the adipose fin length, respectively. At 2 years of age, cells in the adipose fin did not exhibit AR immunoreactivity. However, AR-immunopositive cells were abundant in the adipose fin of 3- to 5-year-old fish. Moreover, the number of AR-immunopositive cells was significantly (P brown trout is a probable target for androgen action and that tissue function or development may to some extent be androgen dependent. In addition, it is likely that such an effect will be mediated by specific androgen receptors.

Relationships of mercury concentrations across tissue types, muscle regions and fins for two shark species

KAUST Repository

O'Bryhim, Jason R.

2017-01-31

Mercury (Hg) exposure poses a threat to both fish and human health. Sharks are known to bioaccumulate Hg, however, little is known regarding how Hg is distributed between different tissue groups (e.g. muscle regions, organs). Here we evaluated total mercury (THg) concentrations from eight muscle regions, four fins (first dorsal, left and right pectorals, caudal-from both the inner core and trailing margin of each fin), and five internal organs (liver, kidney, spleen, heart, epigonal organ) from two different shark species, bonnethead (Sphyrna tiburo) and silky shark (Carcharhinus falciformis) to determine the relationships of THg concentrations between and within tissue groups. Total Hg concentrations were highest in the eight muscle regions with no significant differences in THg concentrations between the different muscle regions and muscle types (red and white). Results from tissue collected from any muscle region would be representative of all muscle sample locations. Total Hg concentrations were lowest in samples taken from the fin inner core of the first dorsal, pectoral, and caudal (lower lobe) fins. Mercury concentrations for samples taken from the trailing margin of the dorsal, pectoral, and caudal fins (upper and lower lobe) were also not significantly different from each other for both species. Significant relationships were found between THg concentrations in dorsal axial muscle tissue and the fin inner core, liver, kidney, spleen and heart for both species as well as the THg concentrations between the dorsal fin trailing margin and the heart for the silky shark and all other sampled tissue types for the bonnethead shark. Our results suggest that biopsy sampling of dorsal muscle can provide data that can effectively estimate THg concentrations in specific organs without using more invasive, or lethal methods.

DETERMINATION OF TOTAL MERCURY IN FISH TISSUES USING PYROLYSIS ATOMIC ABSORPTION SPECTROMETRY WITH GOLD AMALGAMATION

Science.gov (United States)

A simple and rapid procedure for measuring total mercury in fish tissues is evaluated and compared with conventional techniques. Using an automated instrument incorporating combustion, preconcentration by amalgamation with gold, and atomic absorption spectrometry (AAS), mill...

Determination of the exposure parameters that maximise the concentrations of the anaesthetic/sedative eugenol in rainbow trout (Oncorhynchus mykiss) skin-on fillet tissue.

Science.gov (United States)

Meinertz, J R; Porcher, S T; Smerud, J R; Gaikowski, M P

2014-01-01

Studies were conducted to determine the anaesthetic/sedative concentrations and durations that would maximise anaesthetic/sedative residue concentrations in rainbow trout (Oncorhynchus mykiss) skin-on fillet tissue. Rainbow trout (167-404 g) were exposed to 50 mg l(-1) AQUI-S(®) 20E (10% active ingredient, eugenol) in 17°C freshwater for durations up to 1440 min, 100 and 250 mg l(-1) AQUI-S(®) 20E for durations up to 240 min, and 500 and 1000 mg l(-1) AQUI-S(®) 20E for durations up to 90 min. Fish exposed to 100 mg l(-1) AQUI-S(®) 20E for durations of 30, 60, 120 and 240 min had the greatest eugenol concentrations in the fillet tissue, 50, 58, 54 and 62 µg g(-1), respectively. All other exposure concentrations and durations resulted in significantly lower eugenol concentrations, i.e. all < 39 µg g(-1).

Environmental monitoring of the Robertson Reservoir (1990-2005) : evolution of the mercury levels in the flesh of fish

International Nuclear Information System (INIS)

Therrien, J.

2006-04-01

This paper provided details of an environmental monitoring analysis of the stomach contents and mercury levels in the flesh of main fish species in the Robertson Reservoir. The report noted that smelt species were dominant in the reservoir and in the adjoining Ivry Lake, while benthos were dominant the brackish waters of Lake Monger. Sticklebacks were found in the stomachs of the examined fish, while the diet of brook trout was comprised mainly of benthos in lakes and reservoirs. Arctic char mainly ate benthos in the reservoir. Landlocked salmon mainly ate fish in the reservoirs and lakes. Smelt was the primary diet of Arctic char until 2003. After 2003, Arctic char fed mainly on sticklebacks. It was observed that average mercury levels of fish of a standardized length increased by a factor of 2.7 to 4.9 after the impoundment of the reservoir. However, average mercury levels stopped increasing for dwarf Arctic char in 2003. Levels of mercury in brook trout have not increased since 1999. A significant decrease in mercury levels of rainbow smelt were observed. Average mercury levels of fish in the brackish waters of Lake Monger were lower than levels observed in most other freshwater lakes in the region. It was concluded that the number of monthly meals recommended by the fish consumption guide produced in 2001 for the Gros Mecatina region are still appropriate for the reservoir

Plump Cutthroat Trout and Thin Rainbow Trout in a Lentic Ecosystem

OpenAIRE

Courtney, Joshua; Abbott, Jessica; Schmidt, Kerri; Courtney, Michael

2012-01-01

Background: Much has been written about introduced rainbow trout (Oncorhynchus mykiss) interbreeding and outcompeting cutthroat trout (Oncorhynchus clarkii). However, the specific mechanisms by which rainbow trout and their hybrids outcompete cutthroat trout have not been thoroughly explored, and the published data is limited to lotic ecosystems. Materials and Methods: Samples of rainbow trout and cutthroat trout were obtained from a lentic ecosystem by angling. The total length and weight of...

Mercury Concentrations in Fish and Sediment within Streams are Influenced by Watershed and Landscape Variables including Historical Gold Mining in the Sierra Nevada, California

Science.gov (United States)

Alpers, C. N.; Yee, J. L.; Ackerman, J. T.; Orlando, J. L.; Slotton, D. G.; Marvin-DiPasquale, M. C.

2015-12-01

We compiled available data on total mercury (THg) and methylmercury (MeHg) concentrations in fish tissue and streambed sediment from stream sites in the Sierra Nevada, California, to assess whether spatial data, including information on historical mining, can be used to make robust predictions of fish fillet tissue THg concentrations. A total of 1,271 fish from five species collected at 103 sites during 1980-2012 were used for the modeling effort: 210 brown trout, 710 rainbow trout, 79 Sacramento pikeminnow, 93 Sacramento sucker, and 179 smallmouth bass. Sediment data were used from 73 sites, including 106 analyses of THg and 77 analyses of MeHg. The dataset included 391 fish (mostly rainbow trout) and 28 sediment samples collected explicitly for this study during 2011-12. Spatial data on historical mining included the USGS Mineral Resources Data System and publicly available maps and satellite photos showing the areas of hydraulic mine pits and other placer mines. Modeling was done using multivariate linear regression and multi-model inference using Akaike Information Criteria. Results indicate that fish THg, accounting for species and length, can be predicted using geospatial data on mining history together with other landscape characteristics including land use/land cover. A model requiring only geospatial data, with an R2 value of 0.61, predicted fish THg correctly with respect to over-or-under 0.2 μg/g wet weight (a California regulatory threshold) for 108 of 121 (89 %) size-species combinations tested. Data for THg in streambed sediment did not improve the geospatial-only model. However, data for sediment MeHg, loss on ignition (organic content), and percent of sediment less than 0.063 mm resulted in a slightly improved model, with an R2 value of 0.63. It is anticipated that these models will be useful to the State of California and others to predict areas where mercury concentrations in fish are likely to exceed regulatory criteria.

Determination of malachite green residues in the eggs, fry, and adult muscle-tissue of rainbow-trout (Oncorhynchus-mykiss)

Science.gov (United States)

Allen, John L.; Gofus, J.E.; Meinertz, Jeffery R.

1994-01-01

Malachite green, an effective antifungal therapeutant used in fish culture, is a known teratogen. We developed a method to simultaneously detect both the chromatic and leuco forms of malachite green residues in the eggs, fry, and adult muscle tissue of rainbow trout (oncorhynchus mykiss). Homogenates of these tissues were fortified with [c-14] malachite green chloride and extracted with 1% (v/v) acetic acid in acetonitrile or in methanol. The extracts were partitioned with chloroform, dried, redissolved in mobile phase, and analyzed by liquid chromatography (lc) with postcolumn oxidation of leuco malachite green to the chromatic form. Lc fractions were collected every 30 s for quantitation by scintillation counting. Recoveries of total [c-14] malachite green chloride residue were 85 and 98% in eggs fortified with labeled malachite green at concentrations of 0.5 And 1.00 Mug/g, respectively; 68% in fry similarly fortified at a concentration of 0.65 Mug/g; and 66% in muscle homogenate similarly fortified at a level of 1.00 Mug/g. The method was tested under operational conditions by exposing adult rainbow trout to 1.00 Mg/l [c-14] malachite green chloride bath for 1 h. Muscle samples analyzed by sample oxidation and scintillation counting contained 1.3 And 0.5 Mug/g total malachite green chloride residues immediately after exposure and after a 5-day withdrawal period, respectively.

Immunomodulation by heavy metals tested individually or in mixtures in rainbow trout (Oncorhynchus mykiss) exposed in vivo

Energy Technology Data Exchange (ETDEWEB)

Sanchez-Dardon, J.; Voccia, I.; Hontela, A.; Chilmonczyk, S.; Dunier, M.; Boermans, H.; Blakley, B.; Fournier, M.

1999-07-01

The objective of this study was to evaluate the effect of heavy metals, at environmentally relevant concentrations, on the immune response of rainbow trout. Trout were exposed for 30 d to cadmium chloride (CdCl{sub 2}), mercuric chloride (HgCl{sub 2}), or zinc chloride (ZnCl{sub 2}) either individually or in combinations: CdCl{sub 2}/HgCl{sub 2}, CdCl{sub 2}/ZnCl{sub 2}, HgCl{sub 2}/ZnCl{sub 2}, or CdCl{sub 2}/HgCl{sub 2}/ZnCl{sub 2}. Following the 30-d exposure, parameters of the nonspecific cellular immune response (phagocytosis, respiratory burst, and lymphoblastic proliferation) and of the nonspecific humoral immune response (lysozyme activity and the level of immunoglobulin) were measured. The results obtained indicate that individually, all three metals induce significant immunomodulations. However, the toxicity of mercury or cadmium is significantly reduced in fish simultaneously exposed to zinc, indicating that a protection is afforded by zinc against cadmium- and mercury-induced immunotoxicity.

Relations between mercury, methyl-mercury and selenium in tissues of Octopus vulgaris from the Portuguese Coast

Energy Technology Data Exchange (ETDEWEB)

Raimundo, Joana, E-mail: jraimundo@ipimar.p [IPIMAR - National Institute of Biological Resources, Av. Brasilia, 1449-006 Lisbon (Portugal); REQUIMTE - CQFB, Department of Chemistry, Faculty of Sciences and Technology, New University of Lisbon, Qta Torre, 2829-516 Monte da Caparica (Portugal); Vale, Carlos; Canario, Joao; Branco, Vasco [IPIMAR - National Institute of Biological Resources, Av. Brasilia, 1449-006 Lisbon (Portugal); Moura, Isabel [REQUIMTE - CQFB, Department of Chemistry, Faculty of Sciences and Technology, New University of Lisbon, Qta Torre, 2829-516 Monte da Caparica (Portugal)

2010-06-15

Mercury, methyl-mercury (MeHg) and selenium were determined in digestive gland and mantle of Octopus vulgaris, from three areas of the Portuguese coast. To our knowledge these are the first data on MeHg in cephalopods. Concentrations were higher in the digestive gland and percentage of MeHg in mantle. Enhanced Hg and MeHg levels were obtained in digestive gland of specimens from Olhao (3.1-7.4 and 2.0-5.0 mug g{sup -1}, respectively). Differences between areas may be partially related to Hg availability. Relationships between concentrations in mantle and digestive gland pointed to proportional increases of Hg and MeHg in tissues of specimens from Matosinhos and Cascais, but relatively constant values in mantle of individuals from Olhao (higher contamination). Se:Hg molar ratio in digestive gland was 32 and 30 in octopus from Matosinhos and Cascais, respectively, and 5.4 from Olhao. The proximity to the unit suggests demethylation as response to elevated MeHg levels in digestive gland. - Digestive gland presented high accumulation of Hg and MeHg and demethylation processes may occur with the involvement of Se

Relations between mercury, methyl-mercury and selenium in tissues of Octopus vulgaris from the Portuguese Coast

International Nuclear Information System (INIS)

Raimundo, Joana; Vale, Carlos; Canario, Joao; Branco, Vasco; Moura, Isabel

2010-01-01

Mercury, methyl-mercury (MeHg) and selenium were determined in digestive gland and mantle of Octopus vulgaris, from three areas of the Portuguese coast. To our knowledge these are the first data on MeHg in cephalopods. Concentrations were higher in the digestive gland and percentage of MeHg in mantle. Enhanced Hg and MeHg levels were obtained in digestive gland of specimens from Olhao (3.1-7.4 and 2.0-5.0 μg g -1 , respectively). Differences between areas may be partially related to Hg availability. Relationships between concentrations in mantle and digestive gland pointed to proportional increases of Hg and MeHg in tissues of specimens from Matosinhos and Cascais, but relatively constant values in mantle of individuals from Olhao (higher contamination). Se:Hg molar ratio in digestive gland was 32 and 30 in octopus from Matosinhos and Cascais, respectively, and 5.4 from Olhao. The proximity to the unit suggests demethylation as response to elevated MeHg levels in digestive gland. - Digestive gland presented high accumulation of Hg and MeHg and demethylation processes may occur with the involvement of Se

Levels of total mercury in predatory fish sold in Canada in 2005

OpenAIRE

Dabeka, R.W.; McKenzie, A.D.; Forsyth, D.S.

2011-01-01

Total mercury was analysed in 188 samples of predatory fish purchased at the retail level in Canada in 2005. The average concentrations (ng g−1, range) were: sea bass 329 (38–1367), red snapper 148 (36–431), orange roughy 543 (279–974), fresh water trout 55 (20–430), grouper 360 (8–1060), black cod 284 (71–651), Arctic char 37 (28–54), king fish 440 (42–923), tilefish 601 (79–1164) and marlin 854 (125–2346). The Canadian standard for maximum total mercury allowed in the edible portions of fis...

Sexual difference in PCB concentrations of lake trout (Salvelinus namaycush) from Lake Ontario

Science.gov (United States)

Madenjian, Charles P.; Keir, Michael J.; Whittle, D. Michael; Noguchi, George E.

2010-01-01

We determined polychlorinated biphenyl (PCB) concentrations in 61 female lake trout (Salvelinus namaycush) and 71 male lake trout from Lake Ontario (Ontario, Canada and New York, United States). To estimate the expected change in PCB concentration due to spawning, PCB concentrations in gonads and in somatic tissue of lake trout were also determined. In addition, bioenergetics modeling was applied to investigate whether gross growth efficiency (GGE) differed between the sexes. Results showed that, on average, males were 22% higher in PCB concentration than females in Lake Ontario. Results from the PCB determinations of the gonads and somatic tissues revealed that shedding of the gametes led to 3% and 14% increases in PCB concentration for males and females, respectively. Therefore, shedding of the gametes could not explain the higher PCB concentration in male lake trout. According to the bioenergetics modeling results, GGE of males was about 2% higher than adult female GGE, on average. Thus, bioenergetics modeling could not explain the higher PCB concentrations exhibited by the males. Nevertheless, a sexual difference in GGE remained a plausible explanation for the sexual difference in PCB concentrations of the lake trout.

Broad-scale patterns of Brook Trout responses to introduced Brown Trout in New York

Science.gov (United States)

McKenna, James E.; Slattery, Michael T.; Kean M. Clifford,

2013-01-01

Brook Trout Salvelinus fontinalis and Brown Trout Salmo trutta are valuable sport fish that coexist in many parts of the world due to stocking introductions. Causes for the decline of Brook Trout within their native range are not clear but include competition with Brown Trout, habitat alteration, and repetitive stocking practices. New York State contains a large portion of the Brook Trout's native range, where both species are maintained by stocking and other management actions. We used artificial neural network models, regression, principal components analysis, and simulation to evaluate the effects of Brown Trout, environmental conditions, and stocking on the distribution of Brook Trout in the center of their native range. We found evidence for the decline of Brook Trout in the presence of Brown Trout across many watersheds; 22% of sampled reaches where both species were expected to occur contained only Brown Trout. However, a model of the direct relationship between Brook Trout and Brown Trout abundance explained less than 1% of data variation. Ordination showed extensive overlap of Brook Trout and Brown Trout habitat conditions, with only small components of the hypervolume (multidimensional space) being distinctive. Subsequent analysis indicated higher abundances of Brook Trout in highly forested areas, while Brown Trout were more abundant in areas with relatively high proportions of agriculture. Simulation results indicated that direct interactions and habitat conditions were relatively minor factors compared with the effects of repeated stocking of Brown Trout into Brook Trout habitat. Intensive annual stocking of Brown Trout could eliminate resident Brook Trout in less than a decade. Ecological differences, harvest behavior, and other habitat changes can exacerbate Brook Trout losses. Custom stocking scenarios with Brown Trout introductions at relatively low proportions of resident Brook Trout populations may be able to sustain healthy populations of both

Patterns of hybridization of nonnative cutthroat trout and hatchery rainbow trout with native redband trout in the Boise River, Idaho

Science.gov (United States)

Neville, Helen M.; Dunham, Jason B.

2011-01-01

Hybridization is one of the greatest threats to native fishes. Threats from hybridization are particularly important for native trout species as stocking of nonnative trout has been widespread within the ranges of native species, thus increasing the potential for hybridization. While many studies have documented hybridization between native cutthroat trout Oncorhynchus clarkii and nonnative rainbow trout O. mykiss, fewer have focused on this issue in native rainbow trout despite widespread threats from introductions of both nonnative cutthroat trout and hatchery rainbow trout. Here, we describe the current genetic (i.e., hybridization) status of native redband trout O. mykiss gairdneri populations in the upper Boise River, Idaho. Interspecific hybridization was widespread (detected at 14 of the 41 sampled locations), but high levels of hybridization between nonnative cutthroat trout and redband trout were detected in only a few streams. Intraspecific hybridization was considerably more widespread (almost 40% of sampled locations), and several local populations of native redband trout have been almost completely replaced with hatchery coastal rainbow trout O. mykiss irideus; other populations exist as hybrid swarms, some are in the process of being actively invaded, and some are maintaining genetic characteristics of native populations. The persistence of some redband trout populations with high genetic integrity provides some opportunity to conserve native genomes, but our findings also highlight the complex decisions facing managers today. Effective management strategies in this system may include analysis of the specific attributes of each site and population to evaluate the relative risks posed by isolation versus maintaining connectivity, identifying potential sites for control or eradication of nonnative trout, and long-term monitoring of the genetic integrity of remaining redband trout populations to track changes in their status.

A physiological toxicokinetic model for dermal absorption of waterborne pyrene by trout

Energy Technology Data Exchange (ETDEWEB)

Namdari, R.; Law, F.C.P. [Simon Fraser Univ., Burnaby, British Columbia (Canada)

1995-12-31

A physiologically-based toxicokinetic (PB-TK) model was developed to describe the disposition of pyrene in trout following a bolus injection into the dorsal aorta. In the present study, the PB-TK model was adapted for dermal absorption of waterborne pyrene by trout. A skin compartment with transdermal flux described mathematically by the permeability-area-concentration product was added to the PB-TK model to allow prediction of pyrene concentrations in target organs and blood on the basis of exposure concentration at the skin surface. Physiologically relevant parameters e.g., organ volume, blood flow rate, and tissue/blood partitioning coefficient which were derived from the model were similar to those reported in the previous publication. The dermal PB-TK model was validated by exposing the trunk of trout (400--500 g) to stagnant water containing 24 ppm pyrene in a specially designed chamber for 4 hr, 24 hr or 48 hr. The trout were sacrificed at the conclusion of pyrene exposure and the tissues analyzed for unchanged pyrene by HPLC. In separate experiments, trout were implanted with dorsal aorta cannuli before the trunks were exposed to stagnant water containing 24 ppm pyrene in the chamber for 4 hr. At specific time intervals during and after pyrene exposure, blood samples were withdrawn through the cannula and analyzed for pyrene by HPLC. The agreement between simulated and experimentally obtained values shows that this model is an appropriate tool to predict dermal absorption of waterborne pyrene by trout.

Anthropogenic impacts on mercury concentrations and nitrogen and carbon isotope ratios in fish muscle tissue of the Truckee River watershed, Nevada, USA

International Nuclear Information System (INIS)

Sexauer Gustin, Mae; Saito, Laurel; Peacock, Mary

2005-01-01

The lower Truckee River originates at Lake Tahoe, California/Nevada (NV), USA and ends in the terminal water body, Pyramid Lake, NV. The river has minimal anthropogenic inputs of contaminants until it encounters the cities of Reno and Sparks, NV, and receives inflows from Steamboat Creek (SBC). SBC originates at Washoe Lake, NV, where there were approximately six mills that used mercury for gold and silver amalgamation in the late 1800s. Since then, mercury has been distributed down the creek to the Truckee River. In addition, SBC receives agricultural and urban nonpoint source pollution, and treated effluent from the Reno-Sparks water reclamation facility. Fish muscle tissue was collected from different species in SBC and the Truckee River and analyzed for mercury and stable isotopes. Nitrogen (?δ 15 N) and carbon (?δ 13 C) isotopic values in these tissues provide insight as to fish food resources and help to explain their relative Hg concentrations. Mercury concentrations, and ?δ 15 N and ?δ 13 C values in fish muscle from the Truckee River, collected below the SBC confluence, were significantly different than that found in fish collected upstream. Mercury concentrations in fish tissue collected below the confluence for all but three fish sampled were significantly greater (0.1 to 0.65 μg/g wet wt.) than that measured in the tissue collected above the confluence (0.02 to 0.1 μg/g). ?δ 15 N and ?δ 13 C isotopic values of fish muscle collected from the river below the confluence were higher and lower, respectively, than that measured in fish collected up river, most likely reflecting wastewater inputs. The impact of SBC inputs on muscle tissue isotope values declined down river whereas the impact due to Hg inputs showed the opposite trend

Hybridization dynamics between Colorado's native cutthroat trout and introduced rainbow trout.

Science.gov (United States)

Metcalf, Jessica L; Siegle, Matthew R; Martin, Andrew P

2008-01-01

Newly formed hybrid populations provide an opportunity to examine the initial consequences of secondary contact between species and identify genetic patterns that may be important early in the evolution of hybrid inviability. Widespread introductions of rainbow trout (Oncorhynchus mykiss) into watersheds with native cutthroat trout (Oncorhynchus clarkii) have resulted in hybridization. These introductions have contributed to the decline of native cutthroat trout populations. Here, we examine the pattern of hybridization between introduced rainbow trout and 2 populations of cutthroat trout native to Colorado. For this study, we utilized 7 diagnostic, codominant nuclear markers and a diagnostic mitochondrial marker to investigate hybridization in a population of greenback cutthroat trout (Oncorhynchus clarkii stomias) and a population of Colorado River cutthroat trout (Oncorhynchus clarkii pleuriticus). We infer that cutthroat-rainbow trout hybrid swarms have formed in both populations. Although a mixture of hybrid genotypes was present, not all genotype combinations were detected at expected frequencies. We found evidence that mitochondrial DNA introgression in hybrids is asymmetric and more likely from rainbow trout than from cutthroat trout. A difference in spawning time of the 2 species or differences in the fitness between the reciprocal crosses may explain the asymmetry. Additionally, the presence of intraspecific cytonuclear associations found in both populations is concordant with current hypotheses regarding coevolution of mitochondrial and nuclear genomes.

Are brown trout replacing or displacing bull trout populations in a changing climate?

Science.gov (United States)

Al-Chokhachy, Robert K.; Schmetterling, David A.; Clancy, Chris; Saffel, Pat; Kovach, Ryan; Nyce, Leslie; Liermann, Brad; Fredenberg, Wade A.; Pierce, Ron

2016-01-01

Understanding how climate change may facilitate species turnover is an important step in identifying potential conservation strategies. We used data from 33 sites in western Montana to quantify climate associations with native bull trout (Salvelinus confluentus) and non-native brown trout (Salmo trutta) abundance and population growth rates (λ). We estimated λ using exponential growth state space models and delineated study sites based on bull trout use for either Spawning and Rearing (SR) or Foraging, Migrating, and Overwintering (FMO) habitat. Bull trout abundance was negatively associated with mean August stream temperatures within SR habitat (r = -0.75). Brown trout abundance was generally highest at temperatures between 12 and 14°C. We found bull trout λ were generally stable at sites with mean August temperature below 10°C but significantly decreasing, rare, or extirpated at 58% of the sites with temperatures exceeding 10°C. Brown trout λ were highest in SR and sites with temperatures exceeding 12°C. Declining bull trout λs at sites where brown trout were absent suggests brown trout are likely replacing bull trout in a warming climate.

Exogenous lactate supply affects lactate kinetics of rainbow trout, not swimming performance

Science.gov (United States)

Omlin, Teye; Langevin, Karolanne

2014-01-01

Intense swimming causes circulatory lactate accumulation in rainbow trout because lactate disposal (Rd) is not stimulated as strongly as lactate appearance (Ra). This mismatch suggests that maximal Rd is limited by tissue capacity to metabolize lactate. This study uses exogenous lactate to investigate what constrains maximal Rd and minimal Ra. Our goals were to determine how exogenous lactate affects: 1) Ra and Rd of lactate under baseline conditions or during graded swimming, and 2) exercise performance (critical swimming speed, Ucrit) and energetics (cost of transport, COT). Results show that exogenous lactate allows swimming trout to boost maximal Rd lactate by 40% and reach impressive rates of 56 μmol·kg−1·min−1. This shows that the metabolic capacity of tissues for lactate disposal is not responsible for setting the highest Rd normally observed after intense swimming. Baseline endogenous Ra (resting in normoxic water) is not significantly reduced by exogenous lactate supply. Therefore, trout have an obligatory need to produce lactate, either as a fuel for oxidative tissues and/or from organs relying on glycolysis. Exogenous lactate does not affect Ucrit or COT, probably because it acts as a substitute for glucose and lipids rather than extra fuel. We conclude that the observed 40% increase in Rd lactate is made possible by accelerating lactate entry into oxidative tissues via monocarboxylate transporters (MCTs). This observation together with the weak expression of MCTs and the phenomenon of white muscle lactate retention show that lactate metabolism of rainbow trout is significantly constrained by transmembrane transport. PMID:25121611

Brook trout use of thermal refugia and foraging habitat influenced by brown trout

Science.gov (United States)

Hitt, Nathaniel P.; Snook, Erin; Massie, Danielle L.

2017-01-01

The distribution of native brook trout (Salvelinus fontinalis) in eastern North America is often limited by temperature and introduced brown trout (Salmo trutta), the relative importance of which is poorly understood but critical for conservation and restoration planning. We evaluated effects of brown trout on brook trout behavior and habitat use in experimental streams across increasing temperatures (14–23 °C) with simulated groundwater upwelling zones providing thermal refugia (6–9 °C below ambient temperatures). Allopatric and sympatric trout populations increased their use of upwelling zones as ambient temperatures increased, demonstrating the importance of groundwater as thermal refugia in warming streams. Allopatric brook trout showed greater movement rates and more even spatial distributions within streams than sympatric brook trout, suggesting interference competition by brown trout for access to forage habitats located outside thermal refugia. Our results indicate that removal of introduced brown trout may facilitate native brook trout expansion and population viability in downstream reaches depending in part on the spatial configuration of groundwater upwelling zones.

Total mercury and mercury species in birds and fish in an aquatic ecosystem in the Czech Republic

International Nuclear Information System (INIS)

Houserova, Pavlina; Kuban, Vlastimil; Kracmar, Stanislav; Sitko, Jilji

2007-01-01

Total mercury and mercury species (methylmercury-MeHg, inorganic mercury - Hg 2+ ) were determined in the aquatic ecosystem Zahlinice (Czech Republic). Four tissues (muscle, intestines, liver and kidney) of three bird species - cormorant, great crested grebe and Eurasian buzzard, muscle tissues of common carp, grass carp, northern pike, goldfish, common tench, perch and rudd, aquatic plants (reed mace and common reed), sediments and water were analysed. Relative contents of MeHg (of total Hg) were in the range from 71% to 94% and from 15% up to 62% in the muscle and intestines and in liver, respectively, for all birds. Statistically significant differences were found between contents of MeHg in liver tissues of young and adult cormorant populations (F 4.6 = 56.71, P -5 ). Relative contents of MeHg in muscle tissues of fishes were in the range from 65.1% to 87.9% of total Hg. - The distribution of the mercury species among the organs of the individual birds is discussed

Angiotensin extraction by trout tissues in vivo and metabolism by the perfused gill

International Nuclear Information System (INIS)

Olson, K.R.; Kullman, D.; Narkates, A.J.; Oparil, S.

1986-01-01

Plasma clearance and tissue accumulation of 125I-angiotensin I, [Asp1, Ile5]ANG I, and [14C]sucrose, an inert volume reference, were measured after a bolus injection into the dorsal aorta of rainbow trout, Salmo gairdneri. Retention and metabolism of ANG I to angiotensin II (ANG II) and their constituent 1-4 peptide by the gill were examined using an isolated perfused arch preparation in which outflow from the respiratory and central filamental (venous) pathways was separated. Clearance of ANG I from plasma is multiexponential, reflecting dilution and tissue extraction. Liver, bile, gonads, corpuscles of Stannius, and white skeletal muscle accumulate more 125I than 14C; gill tissue accumulates less 125I than 14C. ANG I and II are retained by the perfused gill longer than the inert vascular marker sucrose, even though the distribution volumes of the former are less. The gill respiratory pathway converts ANG I to ANG II whereas the venous pathway metabolizes either ANG I or II to the 1-4 peptide and other metabolites. The gill respiratory pathway is in series with the systemic vasculature, has a large blood-cell contact area, and, like the mammalian lung, is ideally suited to activate ANG I. The gill venous pathway is in parallel with the systemic vasculature and removes ANG II from the circulation. During stress, elevated plasma catecholamines may reduce venous perfusion and thereby help maintain elevated circulating ANG II levels through reduced venous metabolism

Sexual differences in the distribution and retention of organic and inorganic mercury in methyl mercury-treated rats

International Nuclear Information System (INIS)

Thomas, D.J.; Fisher, H.L.; Sumler, M.R.; Marcus, A.H.; Mushak, P.; Hall, L.L.

1986-01-01

At 56 days of age, male and female Long-Evans rats received 1 μmole of 203 Hg-labeled mercuric chloride per kilogram sc and total, organic, and inorganic mercury contents and concentrations in tissues were determined for up to 98 days postdosing. When expressed on a concentration basis, the only significant sexual difference was in the higher average concentration of organic mercury in the kidneys of females. When expressed on a tissue content basis, significant male-female differences in the kinetics (sex x time interactions) of organic mercury retention were found in kidney, brain, skeletal muscle, pelt, and whole body. Significant sex x time interactions in the concentrations of organic mercury were found in kidney, skeletal muscle, and whole body. Kinetics of retention and concentration of inorganic Hg in the pelt differed significantly for males and females. Discordance of degree of statistical significance of differences in mercury contents and concentrations reflected in part differences in relative body composition of males and females. Differences in integrated exposure were estimated by the female-to-male ratio of areas under retention curves. Reconstruction of whole body organic and inorganic mercury burdens from constituent tissues indicated that integrated exposures of males and females to inorganic mercury were equal but females had a lower integrated exposure to organic mercury. Integrated exposure of liver to either form of mercury was about equal in males and females. However, the integrated exposure of the brain of females to inorganic mercury was 2.19 times that of males suggest'ing a sexual difference in accumulation or retention of inorganic mercury in the nervous system

Chemical Form Matters: Differential Accumulation of Mercury Following Inorganic and Organic Mercury Exposures in Zebrafish Larvae

Energy Technology Data Exchange (ETDEWEB)

Korbas, Malgorzata; MacDonald, Tracy C.; Pickering, Ingrid J.; George, Graham N.; Krone, Patrick H. (Saskatchewan)

2013-04-08

Mercury, one of the most toxic elements, exists in various chemical forms each with different toxicities and health implications. Some methylated mercury forms, one of which exists in fish and other seafood products, pose a potential threat, especially during embryonic and early postnatal development. Despite global concerns, little is known about the mechanisms underlying transport and toxicity of different mercury species. To investigate the impact of different mercury chemical forms on vertebrate development, we have successfully combined the zebrafish, a well-established developmental biology model system, with synchrotron-based X-ray fluorescence imaging. Our work revealed substantial differences in tissue-specific accumulation patterns of mercury in zebrafish larvae exposed to four different mercury formulations in water. Methylmercury species not only resulted in overall higher mercury burdens but also targeted different cells and tissues than their inorganic counterparts, thus revealing a significant role of speciation in cellular and molecular targeting and mercury sequestration. For methylmercury species, the highest mercury concentrations were in the eye lens epithelial cells, independent of the formulation ligand (chloride versus L-cysteine). For inorganic mercury species, in absence of L-cysteine, the olfactory epithelium and kidney accumulated the greatest amounts of mercury. However, with L-cysteine present in the treatment solution, mercuric bis-L-cysteineate species dominated the treatment, significantly decreasing uptake. Our results clearly demonstrate that the common differentiation between organic and inorganic mercury is not sufficient to determine the toxicity of various mercury species.

Determination of total mercury in fillets of sport fishes collected from Folsom Reservoir, California, 2006

Science.gov (United States)

May, Thomas W.; Brumbaugh, William G.

2007-01-01

This report presents the results of a study by the U.S. Geological Survey, done in cooperation with the U.S. Bureau of Reclamation, to determine mercury concentrations in selected sport fishes from Folsom Reservoir in California. Fillets were collected from each fish sample, and after homogenization and lyophilization of fish fillets, mercury concentrations were determined with a direct mercury analyzer utilizing the process of thermal combustion-gold amalgamation atomic absorption spectroscopy. Mercury concentrations in fillets ranged from 0.031 to 0.20 micrograms per gram wet weight in rainbow trout (Oncorhynchus mykiss) samples and 0.071 to 0.16 micrograms per gram wet weight in bluegill (Lepomis macrochirus) samples. Mercury concentration was 0.98 microgram per gram wet weight in a single spotted bass (Micropterus punctulatus) sample, which was the only one in the sample set which exceeded the U.S. Environmental Protection Agency's fish consumption advisory of 0.30 microgram per gram wet weight.

Spatial trends and impairment assessment of mercury in sport fish in the Sacramento-San Joaquin Delta watershed

International Nuclear Information System (INIS)

Melwani, A.R.; Bezalel, S.N.; Hunt, J.A.; Grenier, J.L.; Ichikawa, G.; Heim, W.; Bonnema, A.; Foe, C.; Slotton, D.G.; Davis, J.A.

2009-01-01

A three-year study was conducted to examine mercury in sport fish from the Sacramento-San Joaquin Delta. More than 4000 fish from 31 species were collected and analyzed for total mercury in individual muscle filets. Largemouth bass and striped bass were the most contaminated, averaging 0.40 μg/g, while redear sunfish, bluegill and rainbow trout exhibited the lowest (<0.15 μg/g) concentrations. Spatial variation in mercury was evaluated with an analysis of covariance model, which accounted for variability due to fish size and regional hydrology. Significant regional differences in mercury were apparent in size-standardized largemouth bass, with concentrations on the Cosumnes and Mokelumne rivers significantly higher than the central and western Delta. Significant prey-predator mercury correlations were also apparent, which may explain a significant proportion of the spatial variation in the watershed. - Regional differences in sport fish mercury were found in the Sacramento-San Joaquin Delta.

Green Tea Increases the Concentration of Total Mercury in the Blood of Rats following an Oral Fish Tissue Bolus

Directory of Open Access Journals (Sweden)

Elsa M. Janle

2015-01-01

Full Text Available Fish has many health benefits but is also the most common source of methylmercury. The bioavailability of methylmercury in fish may be affected by other meal components. In this study, the effect of green tea on the bioavailability of methylmercury from an oral bolus of fish muscle tissue was studied in rats and compared to a water treated control group and a group treated with meso-2,3-dimercaptosuccinic acid (DMSA, a compound used medically to chelate mercury. Rats were given a single oral dose of fish tissue via gavage and one of the treatments. Rats were given access to food for 3 h at 12 h intervals. They were dosed with each of the treatments with each meal. Blood samples were collected for 95 hours. Green tea significantly increased the concentration of total mercury in blood relative to the control, whereas DMSA significantly decreased it. In addition, feeding caused a slight increase in blood mercury for several meals following the initial dose.

OCCURRENCE OF INFECTIOUS PANCREATIC NECROSIS VIRUS (IPNV) IN FARMED RAINBOW TROUT (ONCHORHYNCHUS MYKISS) IN KOSOVO

OpenAIRE

Agim Rexhepi; Kristaq Berxholli; Peter Scheinert; Afrim Hamidi; Kurtesh Sherifi

2013-01-01

This article describes the research carried out for the detection of viruses responsible for VHS, IHN and IPN diseases in farmed rainbow trout (Oncorhynchus mykiss) in Kosovo for the three-year period between 2006 and 2008. Losses are often reported in trout fingerlings, but no virus has ever been isolated in the rainbow trout in Kosovo. A research project was carried out to determine the occurrence of VHSV, IHNV & IPNV from the samples of fish tissue and ovarian fluids from mature broodf...

Total mercury and mercury species in birds and fish in an aquatic ecosystem in the Czech Republic

Energy Technology Data Exchange (ETDEWEB)

Houserova, Pavlina [Department of Chemistry and Biochemistry, Mendel University of Agriculture and Forestry, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Kuban, Vlastimil [Department of Chemistry and Biochemistry, Mendel University of Agriculture and Forestry, Zemedelska 1, CZ-613 00 Brno (Czech Republic)]. E-mail: kuban@mendelu.cz; Kracmar, Stanislav [Department of Animal Nutrition, Mendel University of Agriculture and Forestry, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Sitko, Jilji [Commenius Museum, Moravian Ornithological Station, Horni nam. 1, Prerov CZ-751 52 (Czech Republic)

2007-01-15

Total mercury and mercury species (methylmercury-MeHg, inorganic mercury - Hg{sup 2+}) were determined in the aquatic ecosystem Zahlinice (Czech Republic). Four tissues (muscle, intestines, liver and kidney) of three bird species - cormorant, great crested grebe and Eurasian buzzard, muscle tissues of common carp, grass carp, northern pike, goldfish, common tench, perch and rudd, aquatic plants (reed mace and common reed), sediments and water were analysed. Relative contents of MeHg (of total Hg) were in the range from 71% to 94% and from 15% up to 62% in the muscle and intestines and in liver, respectively, for all birds. Statistically significant differences were found between contents of MeHg in liver tissues of young and adult cormorant populations (F {sub 4.6} = 56.71, P < 10{sup -5}). Relative contents of MeHg in muscle tissues of fishes were in the range from 65.1% to 87.9% of total Hg. - The distribution of the mercury species among the organs of the individual birds is discussed.

Brown Trout removal effects on short-term survival and movement of Myxobolus cerebralis-resistant rainbow trout

Science.gov (United States)

Fetherman, Eric R.; Winkelman, Dana L.; Bailey, Larissa L.; Schisler, George J.; Davies, K.

2015-01-01

Following establishment of Myxobolus cerebralis (the parasite responsible for salmonid whirling disease) in Colorado, populations of Rainbow Trout Oncorhynchus mykissexperienced significant declines, whereas Brown Trout Salmo trutta densities increased in many locations across the state, potentially influencing the success of M. cerebralis-resistant Rainbow Trout reintroductions. We examined the effects of Brown Trout removal on the short-term (3-month) survival and movement of two crosses of reintroduced, M. cerebralis-resistant Rainbow Trout in the Cache la Poudre River, Colorado. Radio frequency identification passive integrated transponder tags and antennas were used to track movements of wild Brown Trout and stocked Rainbow Trout in reaches where Brown Trout had or had not been removed. Multistate mark–recapture models were used to estimate tagged fish apparent survival and movement in these sections 3 months following Brown Trout removal. A cross between the German Rainbow Trout and Colorado River Rainbow Trout strains exhibited similar survival and movement probabilities in the reaches, suggesting that the presence of Brown Trout did not affect its survival or movement. However, a cross between the German Rainbow Trout and Harrison Lake Rainbow Trout exhibited less movement from the reach in which Brown Trout had been removed. Despite this, the overall short-term benefits of the removal were equivocal, suggesting that Brown Trout removal may not be beneficial for the reintroduction of Rainbow Trout. Additionally, the logistical constraints of conducting removals in large river systems are substantial and may not be a viable management option in many rivers.

Organic contaminants in thermal plume resident brown trout

International Nuclear Information System (INIS)

Romberg, G.P.; Bourne, S.

1978-01-01

A pilot study was conducted to identify possible contaminants accumulated by thermal plume-resident fish in Lake Michigan. Brown trout were maintained in tanks receiving intake and discharge (less than or equal to 21 0 C) water from a power plant and were fed a diet of frozen alewife. Fish were sampled over a period of 127 days in order to estimate uptake rates and equilibrium levels for toxic organic and inorganic materials occurring in Lake Michigan fish and water. Experimental fish and natural samples were analyzed to determine the distribution of contaminants in various tissues and the corresponding pollutant levels in similar size brown trout from Lake Michigan. The quantitative analyses for the major organic contaminants are summarized. Without exception, the pyloric caecum of brown trout contained the highest concentration of lipids, PCB's, and chlorinated pesticides. Gill and kidney samples contained lower concentrations of contaminants than the caecum, while liver and muscle values were lowest

Distribution and retention of organic and inorganic mercury in methyl mercury-treated neonatal rats

International Nuclear Information System (INIS)

Thomas, D.J.; Fisher, H.L.; Sumler, M.R.; Hall, L.L.; Mushak, P.

1988-01-01

Seven-day-old Long Evans rats received one mumol of 203 Hg-labeled methyl mercury/kg sc and whole body retention and tissue distribution of organic and inorganic mercury were examined for 32 days postdosing. Neonates cleared mercury slowly until 10 days postdosing when the clearance rate abruptly increased. During the interval when whole body clearance of mercury was extremely slow, methyl mercury was metabolized to inorganic mercury. Peak concentration of mercury in kidney occurred at 2 days postdosing. At 32 days postdosing, 8% of mercury in kidney was in an organic from. Liver mercury concentration peaked at 2 days postdosing and organic mercury accounted for 38% at 32 days postdosing. Brain concentrations of mercury peaked at 2 days postdosing. At 10 days postdosing, organic mercury accounted for 86% of the brain mercury burden, and, at 32 days postdosing, for 60%. The percentage of mercury body burden in pelt rose from 30 to 70% between 1 and 10 days postdosing. At 32 days postdosing pelt contained 85% of the body burden of mercury. At all time points, about 95% of mercury in pelt was in an organic form. Compartmental analysis of these data permitted development of a model to describe the distribution and excretion of organic and inorganic mercury in methyl mercury-treated neonatal rats

Growth, morphology, and developmental instability of rainbow trout, Yellowstone cutthroat trout, and four hybrid generations

Science.gov (United States)

Ostberg, C.O.; Duda, J.J.; Graham, J.H.; Zhang, S.; Haywood, K. P.; Miller, B.; Lerud, T.L.

2011-01-01

Hybridization of cutthroat trout Oncorhynchus clarkii with nonindigenous rainbow trout O. mykiss contributes to the decline of cutthroat trout subspecies throughout their native range. Introgression by rainbow trout can swamp the gene pools of cutthroat trout populations, especially if there is little selection against hybrids. We used rainbow trout, Yellowstone cutthroat trout O. clarkii bouvieri, and rainbow trout × Yellowstone cutthroat trout F1 hybrids as parents to construct seven different line crosses: F1 hybrids (both reciprocal crosses), F2 hybrids, first-generation backcrosses (both rainbow trout and Yellowstone cutthroat trout), and both parental taxa. We compared growth, morphology, and developmental instability among these seven crosses reared at two different temperatures. Growth was related to the proportion of rainbow trout genome present within the crosses. Meristic traits were influenced by maternal, additive, dominant, overdominant, and (probably) epistatic genetic effects. Developmental stability, however, was not disturbed in F1 hybrids, F2 hybrids, or backcrosses. Backcrosses were morphologically similar to their recurrent parent. The lack of developmental instability in hybrids suggests that there are few genetic incompatibilities preventing introgression. Our findings suggest that hybrids are not equal: that is, growth, development, character traits, and morphology differ depending on the genomic contribution from each parental species as well as the hybrid generation.

Competition and predation as mechanisms for displacement of greenback cutthroat trout by brook trout

Science.gov (United States)

C. C. McGrath; W. M. Lewis

2007-01-01

Cutthroat trout Oncorhynchus clarkii frequently are displaced by nonnative brook trout Salvelinus fontinalis, but the ecological mechanisms of displacement are not understood. Competition for food and predation between greenback cutthroat trout O. c. stomias and brook trout were investigated in montane streams of...

OCCURRENCE OF INFECTIOUS PANCREATIC NECROSIS VIRUS (IPNV IN FARMED RAINBOW TROUT (ONCHORHYNCHUS MYKISS IN KOSOVO

Directory of Open Access Journals (Sweden)

Agim Rexhepi

2013-10-01

Full Text Available This article describes the research carried out for the detection of viruses responsible for VHS, IHN and IPN diseases in farmed rainbow trout (Oncorhynchus mykiss in Kosovo for the three-year period between 2006 and 2008. Losses are often reported in trout fingerlings, but no virus has ever been isolated in the rainbow trout in Kosovo. A research project was carried out to determine the occurrence of VHSV, IHNV & IPNV from the samples of fish tissue and ovarian fluids from mature broodfish. In total, 467 fishes from 113 (pools in 10 rainbow trout aquaculture facilities were screened. Laboratory analysis was performed at the TGD (Tiergesundheitsdienst Bayern e. V laboratory in Germany using the biomolecular method of RT-PCR and nested-PCR. The Infectious Pancreatic Necrosis virus was detected in seven trout farms, and prevalence from total samples (pools was 11.5 %. This is the first research and report for IPN virus diagnosis in farmed rainbow trout fry, on-growing fish and broodfish in Kosovo. Keywords: Rainbow trout, viral diseases, IPN, RT-PCR, nested PCR

Fall and winter survival of brook trout and brown trout in a north-central Pennsylvania watershed

Science.gov (United States)

Sweka, John A.; Davis, Lori A.; Wagner, Tyler

2017-01-01

Stream-dwelling salmonids that spawn in the fall generally experience their lowest survival during the fall and winter due to behavioral changes associated with spawning and energetic deficiencies during this time of year. We used data from Brook Trout Salvelinus fontinalis and Brown Trout Salmo trutta implanted with radio transmitters in tributaries of the Hunts Run watershed of north-central Pennsylvania to estimate survival from the fall into the winter seasons (September 2012–February 2013). We examined the effects that individual-level covariates (trout species, size, and movement rates) and stream-level covariates (individual stream and cumulative drainage area of a stream) have on survival. Brook Trout experienced significantly lower survival than Brown Trout, especially in the early fall during their peak spawning period. Besides a significant species effect, none of the other covariates examined influenced survival for either species. A difference in life history between these species, with Brook Trout having a shorter life expectancy than Brown Trout, is likely the primary reason for the lower survival of Brook Trout. However, Brook Trout also spawn earlier in the fall than Brown Trout and low flows during Brook Trout spawning may have resulted in a greater risk of predation for Brook Trout compared with Brown Trout, thereby also contributing to the observed differences in survival between these species. Our estimates of survival can aid parameterization of future population models for Brook Trout and Brown Trout through the spawning season and into winter.

An assessment of mercury in estuarine sediment and tissue in Southern New Jersey using public domain data

Science.gov (United States)

Ng, Kara; Szabo, Zoltan; Reilly, Pamela A.; Barringer, Julia; Smalling, Kelly L.

2016-01-01

Mercury (Hg) is considered a contaminant of global concern for coastal environments due to its toxicity, widespread occurrence in sediment, and bioaccumulation in tissue. Coastal New Jersey, USA, is characterized by shallow bays and wetlands that provide critical habitat for wildlife but share space with expanding urban landscapes. This study was designed as an assessment of the magnitude and distribution of Hg in coastal New Jersey sediments and critical species using publicly available data to highlight potential data gaps. Mercury concentrations in estuary sediments can exceed 2 μg/g and correlate with concentrations of other metals. Based on existing data, the concentrations of Hg in mussels in southern New Jersey are comparable to those observed in other urbanized Atlantic Coast estuaries. Lack of methylmercury data for sediments, other media, and tissues are data gaps needing to be filled for a clearer understanding of the impacts of Hg inputs to the ecosystem.

Microsomal biotransformation of chlorpyrifos, parathion and fenthion in rainbow trout (Oncorhynchus mykiss) and coho salmon (Oncorhynchus kisutch): mechanistic insights into interspecific differences in toxicity

Science.gov (United States)

Lavado, Ramon

2010-01-01

Rainbow trout often serve as a surrogate species evaluating xenobiotic toxicity in cold-water species including other salmonids of the same genus, which are listed as threatened or endangered. Biotransformation tends to show species-specific patterns that influence susceptibility to xenobiotic toxicity, particularly organophoshpate insecticides (OPs). To evaluate the contribution of biotransformation in the mechanism of toxicity of three organophosphate (phosphorothionate) insecticides, chlorpyrifos, parathion and fenthion, microsomal bioactivation and detoxification pathways were measured in gills, liver and olfactory tissues in juvenile rainbow trout (Oncorhynchus mykiss) and compared to juvenile coho salmon (Oncorhynchus kisutch). Consistent with species differences in acute toxicity, significantly higher chlorpyrifos bioactivation was found in liver microsomes of rainbow trout (up to 2-fold) when compared with coho salmon. Although bioactivation to the oxon was observed, the catalytic efficiency towards chlorpyrifos dearylation (detoxification) was significantly higher in liver for both species (1.82 and 0.79 for trout and salmon, respectively) when compared to desulfuration (bioactivation). Bioactivation of parathion to paraoxon was significantly higher (up to 2.2-fold) than detoxification to p-nitrophenol in all tissues of both species with rates of conversion in rainbow trout, again significantly higher than coho salmon. Production of fenoxon and fenthion sulfoxides from fenthion was detected only in liver and gills of both species with activities in rainbow trout significantly higher than coho salmon. NADPH-Dependent hydrolysis of fenthion was observed in all tissues, and was the only activity detected in olfactory tissues. These results indicate rainbow trout are more sensitive than coho salmon to the acute toxicity of OP pesticides because trout have higher catalytic rates of oxon formation. Thus, rainbow trout may serve as a conservative surrogate

Distribution and excretion of inhaled mercury vapour

Energy Technology Data Exchange (ETDEWEB)

Gage, J C

1961-01-01

Rats have been exposed for varying periods to an atmosphere containing 1 mg/cu.m. mercury vapor. The toxic effects produced showed resemblances to signs of mercurialism in man. An attempt has been made to study the kinetics of absorption and excretion of mercury from measurements of the amounts excreted and stored in the tissues. The efficiency of absorption of mercury by the rat lung is about 50%. A small proportion is excreted into the gut. After about 10 days of continuous exposure a steady state is reached in which excretion balances absorption. During short exposures the turnover of mercury in all tissues except brain is fairly rapid and most of the mercury is cleared from the body within a week after exposure. The urinary excretion of mercury, during the initial stage of storage in the tissues and the final stage of clearance, shows divergencies from the simple exponential pattern; there appears to be a delay mechanism in the kidney which, in intermittent exposures, may result in the occurrence of peak excretion during periods of non-exposure. After more prolonged exposures the mercury in the kidney appears to be converted to a form which is only very slowly excreted. The significance of the urinary excretion of mercury by man after industrial exposure to mercury vapour is discussed. The rat experiments suggest that single measurements will give only limited information concerning industrial conditions, but that an approximate assessment of the total absorbed during a working week would be obtained if it were possible to make a seven-day collection of urine. Repeated measurements after exposure would yield information on the duration of exposure and would have some diagnostic value.

Radio-transmitted electromyogram signals as indicators of swimming speed in lake trout and brown trout

DEFF Research Database (Denmark)

Thorstad, E.B.; Økland, F.; Koed, Anders

2000-01-01

Swimming speed and average electromyogram (EMG) pulse intervals were highly correlated in individual lake trout Salvelinus namaycush (r(2)=0.52-0.89) and brown trout Salmo trutta (r(2)=0.45-0.96). High correlations were found also for pooled data in both lake trout (r(2)=0.90) and brown trout...... of the Ema stock (r(2)=0.96) and Laerdal stock (r(2)=0.96). The linear relationship between swimming speed and average EMG pulse intervals differed significantly among lake trout and the brown trout stocks. This successful calibration of EMGs to swimming speed opens the possibility of recording swimming...... speed of free swimming lake trout and brown trout in situ. EMGs can also be calibrated to oxygen consumption to record energy expenditure. (C) 2000 The Fisheries Society of the British Isles...

Lake trout (Salvelinus namaycush) suppression for bull trout (Salvelinus confluentus) recovery in Flathead Lake, Montana, North America

Science.gov (United States)

Hansen, Michael J.; Hansen, Barry S; Beauchamp, David A.

2016-01-01

Non-native lake trout Salvelinus namaycush displaced native bull trout Salvelinus confluentus in Flathead Lake, Montana, USA, after 1984, when Mysis diluviana became abundant following its introduction in upstream lakes in 1968–1976. We developed a simulation model to determine the fishing mortality rate on lake trout that would enable bull trout recovery. Model simulations indicated that suppression of adult lake trout by 75% from current abundance would reduce predation on bull trout by 90%. Current removals of lake trout through incentivized fishing contests has not been sufficient to suppress lake trout abundance estimated by mark-recapture or indexed by stratified-random gill netting. In contrast, size structure, body condition, mortality, and maturity are changing consistent with a density-dependent reduction in lake trout abundance. Population modeling indicated total fishing effort would need to increase 3-fold to reduce adult lake trout population density by 75%. We conclude that increased fishing effort would suppress lake trout population density and predation on juvenile bull trout, and thereby enable higher abundance of adult bull trout in Flathead Lake and its tributaries.

Avian mercury exposure and toxicological risk across western North America: A synthesis

Science.gov (United States)

Ackerman, Joshua T.; Eagles-Smith, Collin A.; Herzog, Mark; Hartman, Christopher; Peterson, Sarah; Evers, David C.; Jackson, Allyson K.; Elliott, John E.; Vander Pol, Stacy S.; Bryan, Colleen E.

2016-01-01

Methylmercury contamination of the environment is an important issue globally, and birds are useful bioindicators for mercury monitoring programs. The available data on mercury contamination of birds in western North America were synthesized. Original data from multiple databases were obtained and a literature review was conducted to obtain additional mercury concentrations. In total, 29219 original bird mercury concentrations from 225 species were compiled, and an additional 1712 mean mercury concentrations, representing 19998 individuals and 176 species, from 200 publications were obtained. To make mercury data comparable across bird tissues, published equations of tissue mercury correlations were used to convert all mercury concentrations into blood-equivalent mercury concentrations. Blood-equivalent mercury concentrations differed among species, foraging guilds, habitat types, locations, and ecoregions. Piscivores and carnivores exhibited the greatest mercury concentrations, whereas herbivores and granivores exhibited the lowest mercury concentrations. Bird mercury concentrations were greatest in ocean and salt marsh habitats and lowest in terrestrial habitats. Bird mercury concentrations were above toxicity benchmarks in many areas throughout western North America, and multiple hotspots were identified. Additionally, published toxicity benchmarks established in multiple tissues were summarized and translated into a common blood-equivalent mercury concentration. Overall, 66% of birds sampled in western North American exceeded a blood-equivalent mercury concentration of 0.2 μg/g wet weight (ww; above background levels), which is the lowest-observed effect level, 28% exceeded 1.0 μg/g ww (moderate risk), 8% exceeded 3.0 μg/g ww (high risk), and 4% exceeded 4.0 μg/g ww (severe risk). Mercury monitoring programs should sample bird tissues, such as adult blood and eggs, that are most-easily translated into tissues with well-developed toxicity benchmarks and that

Influence of water chemistry and natural organic matter on active and passive uptake of inorganic mercury by gills of rainbow trout (Oncorhynchus mykiss)

International Nuclear Information System (INIS)

Klinck, Joel; Dunbar, Michael; Brown, Stephanie; Nichols, Joel; Winter, Anna; Hughes, Christopher; Playle, Richard C.

2005-01-01

To distinguish physiologically regulated uptake from passive uptake of inorganic Hg in fish, rainbow trout (Oncorhynchus mykiss) were exposed to inorganic Hg (0.5, 1, or 2 μM total Hg) in ion-poor water with various treatments. Addition of ions to the water (mM concentrations of Ca, K, Cl) did not consistently alter Hg accumulation by trout gills, although there was a trend to higher Hg accumulation at higher ion concentrations. The apical Ca channel blockers Verapamil and lanthanum also did not consistently affect Hg accumulation by trout gills. Pre-treatment of trout with the Na channel blocker Phenamil decreased Hg uptake by about half. These results suggest a combination of physiologically regulated and passive uptake of Hg by trout gills. Strong complexing agents of Hg (EDTA, NTA, ethylenediamine, cysteine) decreased Hg-binding by trout gills in a dose-dependent manner. From these data, a conditional equilibrium binding constant for Hg to the gills was estimated as log K Hg-gill = 18.0, representing very strong binding of Hg to the gills. This value is a first step in creating a biotic ligand model (BLM) for inorganic Hg and fish. Natural organic matter (2-10 mg C/L) also decreased Hg-binding by trout gills, although mM concentrations of Na, K, and Cl interfered with this effect. At low concentrations of these ions, natural organic matter samples isolated from various sources bound Hg to similar degrees, as judged by Hg accumulation by trout gills. A conditional binding constant to natural organic matter (NOM) was estimated as log K Hg-NOM = 18.0 with about 0.5 μmol binding sites per mg C, representing strong binding of Hg to NOM

Influence of water chemistry and natural organic matter on active and passive uptake of inorganic mercury by gills of rainbow trout (Oncorhynchus mykiss)

Energy Technology Data Exchange (ETDEWEB)

Klinck, Joel [Department of Biology, Wilfrid Laurier University, Waterloo, Ont., N2L 3C5 (Canada); Dunbar, Michael [Department of Biology, Wilfrid Laurier University, Waterloo, Ont., N2L 3C5 (Canada); Brown, Stephanie [Department of Biology, Wilfrid Laurier University, Waterloo, Ont., N2L 3C5 (Canada); Nichols, Joel [Department of Biology, Wilfrid Laurier University, Waterloo, Ont., N2L 3C5 (Canada); Winter, Anna [Department of Biology, Wilfrid Laurier University, Waterloo, Ont., N2L 3C5 (Canada); Hughes, Christopher [Department of Biology, Wilfrid Laurier University, Waterloo, Ont., N2L 3C5 (Canada); Playle, Richard C. [Department of Biology, Wilfrid Laurier University, Waterloo, Ont., N2L 3C5 (Canada)]. E-mail: rplayle@wlu.ca

2005-03-25

To distinguish physiologically regulated uptake from passive uptake of inorganic Hg in fish, rainbow trout (Oncorhynchus mykiss) were exposed to inorganic Hg (0.5, 1, or 2 {mu}M total Hg) in ion-poor water with various treatments. Addition of ions to the water (mM concentrations of Ca, K, Cl) did not consistently alter Hg accumulation by trout gills, although there was a trend to higher Hg accumulation at higher ion concentrations. The apical Ca channel blockers Verapamil and lanthanum also did not consistently affect Hg accumulation by trout gills. Pre-treatment of trout with the Na channel blocker Phenamil decreased Hg uptake by about half. These results suggest a combination of physiologically regulated and passive uptake of Hg by trout gills. Strong complexing agents of Hg (EDTA, NTA, ethylenediamine, cysteine) decreased Hg-binding by trout gills in a dose-dependent manner. From these data, a conditional equilibrium binding constant for Hg to the gills was estimated as log K {sub Hg-gill} = 18.0, representing very strong binding of Hg to the gills. This value is a first step in creating a biotic ligand model (BLM) for inorganic Hg and fish. Natural organic matter (2-10 mg C/L) also decreased Hg-binding by trout gills, although mM concentrations of Na, K, and Cl interfered with this effect. At low concentrations of these ions, natural organic matter samples isolated from various sources bound Hg to similar degrees, as judged by Hg accumulation by trout gills. A conditional binding constant to natural organic matter (NOM) was estimated as log K {sub Hg-NOM} = 18.0 with about 0.5 {mu}mol binding sites per mg C, representing strong binding of Hg to NOM.

Influence of water chemistry and natural organic matter on active and passive uptake of inorganic mercury by gills of rainbow trout (Oncorhynchus mykiss).

Science.gov (United States)

Klinck, Joel; Dunbar, Michael; Brown, Stephanie; Nichols, Joel; Winter, Anna; Hughes, Christopher; Playle, Richard C

2005-03-25

To distinguish physiologically regulated uptake from passive uptake of inorganic Hg in fish, rainbow trout (Oncorhynchus mykiss) were exposed to inorganic Hg (0.5, 1, or 2 microM total Hg) in ion-poor water with various treatments. Addition of ions to the water (mM concentrations of Ca, K, Cl) did not consistently alter Hg accumulation by trout gills, although there was a trend to higher Hg accumulation at higher ion concentrations. The apical Ca channel blockers Verapamil and lanthanum also did not consistently affect Hg accumulation by trout gills. Pre-treatment of trout with the Na channel blocker Phenamil decreased Hg uptake by about half. These results suggest a combination of physiologically regulated and passive uptake of Hg by trout gills. Strong complexing agents of Hg (EDTA, NTA, ethylenediamine, cysteine) decreased Hg-binding by trout gills in a dose-dependent manner. From these data, a conditional equilibrium binding constant for Hg to the gills was estimated as logK(Hg-gill) = 18.0, representing very strong binding of Hg to the gills. This value is a first step in creating a biotic ligand model (BLM) for inorganic Hg and fish. Natural organic matter (2-10 mg C/L) also decreased Hg-binding by trout gills, although mM concentrations of Na, K, and Cl interfered with this effect. At low concentrations of these ions, natural organic matter samples isolated from various sources bound Hg to similar degrees, as judged by Hg accumulation by trout gills. A conditional binding constant to natural organic matter (NOM) was estimated as logK(Hg-NOM) = 18.0 with about 0.5 micromol binding sites per mg C, representing strong binding of Hg to NOM.

Presence of specific growth hormone binding sites in rainbow trout (Oncorhynchus mykiss) tissues: characterization of the hepatic receptor

Energy Technology Data Exchange (ETDEWEB)

Yao, K.; Niu, P.D.; Le Gac, F.; Le Bail, P.Y. (Laboratoire de Physiologie des Poissons, INRA, Rennes, (France))

1991-01-01

The present work outlines the presence of specific binding for chinook salmon growth hormone (sGH) in different tissue preparations of rainbow trout. Optimal incubation conditions (pH, Tris, MgCl{sub 2}) were determined. Specific binding was very sensitive to salt concentration during incubation. The specific binding reached a plateau after 15 and 25 hr of incubation at 12 and 4 {degree}. At 20 {degree}, specific and nonspecific binding were not stable. Specific binding dissociation was slower than association and was only partial. The binding was saturable (Bmax = 187 +/- 167 pmol), of high affinity (Ka = 2.4 +/- 0.8 10(9) M-1), and very specific for GH, properties which are in agreement with the characteristics of hormonal receptors. Sea bream and mammalian GH appeared 2- and 30-fold, respectively, less potent than cold sGH2 for displacing {sup 125}I-sGH2. Tissue preparations from ovary, testis, fat, skin, cartilage, gill, blood pellet, brain, spleen, kidney, and muscle showed significant saturable binding.

Presence of specific growth hormone binding sites in rainbow trout (Oncorhynchus mykiss) tissues: characterization of the hepatic receptor

International Nuclear Information System (INIS)

Yao, K.; Niu, P.D.; Le Gac, F.; Le Bail, P.Y.

1991-01-01

The present work outlines the presence of specific binding for chinook salmon growth hormone (sGH) in different tissue preparations of rainbow trout. Optimal incubation conditions (pH, Tris, MgCl 2 ) were determined. Specific binding was very sensitive to salt concentration during incubation. The specific binding reached a plateau after 15 and 25 hr of incubation at 12 and 4 degree. At 20 degree, specific and nonspecific binding were not stable. Specific binding dissociation was slower than association and was only partial. The binding was saturable (Bmax = 187 +/- 167 pmol), of high affinity (Ka = 2.4 +/- 0.8 10(9) M-1), and very specific for GH, properties which are in agreement with the characteristics of hormonal receptors. Sea bream and mammalian GH appeared 2- and 30-fold, respectively, less potent than cold sGH2 for displacing 125 I-sGH2. Tissue preparations from ovary, testis, fat, skin, cartilage, gill, blood pellet, brain, spleen, kidney, and muscle showed significant saturable binding

Movement and survival of brown trout and rainbow trout in an ozark tailwater river

Science.gov (United States)

Quinn, J.W.; Kwak, T.J.

2011-01-01

We evaluated the movement of adult brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss in relation to a catch-andrelease area in the White River downstream from Beaver Dam, Arkansas. Nine fish of each species were implanted with radio transmitters and monitored from July 1996 to July 1997. The 1.5- km river length of a catch-and-release area (closed to angler harvest) was greater than the total linear range of 72% of the trout (13 of 18 fish), but it did not include two brown trout spawning riffles, suggesting that it effectively protects resident fish within the catch-and-release area except during spawning. The total detected linear range of movement varied from 172 to 3,559 m for brown trout and from 205 to 3,023mfor rainbow trout. The movements of both species appeared to be generally similar to that in unregulated river systems. The annual apparent survival of both trout species was less than 0.40, and exploitation was 44%.Management to protect fish on spawning riffles may be considered if management for wild brown trout becomes a priority. ?? American Fisheries Society 2011.

Cadmium, mercury and selenium concentrations in mink (Mustela vison) from Yukon, Canada

Energy Technology Data Exchange (ETDEWEB)

Gamberg, Mary [Gamberg Consulting, Box 10460, Whitehorse, Yukon, Y1A 7A1 (Canada)]. E-mail: mary.gamberg@northwestel.net; Boila, Gail [Freshwater Institute, Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, MB, R3T 2N6 (Canada); Stern, Gary [Freshwater Institute, Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, MB, R3T 2N6 (Canada); Roach, Patrick [Department of Indian and Northern Affairs, Suite 300, 300 Main Street, Whitehorse, Yukon, Y1A 2B5 (Canada)

2005-12-01

Mercury (total and methyl), cadmium and selenium concentrations were measured in liver, kidney and brain tissue from mink trapped from the Yukon Territory from 2001-2002. None of these metals was found at levels of toxicological concern. Total mercury averaged 0.66, 0.92 and 0.22 {mu}g g{sup -1} in mink kidney, liver and brain tissue respectively, while methyl mercury averaged 0.77, 0.85 and 0.21 {mu}g g{sup -1} in the same tissues. Selenium averaged 2.07, 1.40 and 0.39 {mu}g g{sup -1} in mink kidney, liver and brain tissue, while cadmium was only measured in kidneys and averaged 0.22 {mu}g g{sup -1}. All element concentrations are presented on a wet weight basis. Concentrations of total mercury in all tissues were significantly higher in female than male mink, possibly reflecting proportionally greater food consumption by the smaller females. Total mercury concentrations were inversely related to the proportion of mercury present as methylmercury, and positively related to concentrations of selenium, consistent with increasing demethylation of methylmercury, and the formation of mercuric selenide as total concentrations of mercury increased. This relationship was seen most strongly in mink liver, less so in kidneys and not at all in brains where most of the mercury was maintained in the methyl form. There did not appear to be any geographical areas in which mink had obviously higher concentrations of mercury, and there was frequently a relatively large range of mercury levels found in mink from a given trapline. Mink diet may be a factor in this variation. Local environmental levels of cadmium were not reflected in cadmium concentrations in mink tissues. Mercury, cadmium and selenium do not appear to constitute environmental hazards to mink in the Yukon.

Cadmium, mercury and selenium concentrations in mink (Mustela vison) from Yukon, Canada

International Nuclear Information System (INIS)

Gamberg, Mary; Boila, Gail; Stern, Gary; Roach, Patrick

2005-01-01

Mercury (total and methyl), cadmium and selenium concentrations were measured in liver, kidney and brain tissue from mink trapped from the Yukon Territory from 2001-2002. None of these metals was found at levels of toxicological concern. Total mercury averaged 0.66, 0.92 and 0.22 μg g -1 in mink kidney, liver and brain tissue respectively, while methyl mercury averaged 0.77, 0.85 and 0.21 μg g -1 in the same tissues. Selenium averaged 2.07, 1.40 and 0.39 μg g -1 in mink kidney, liver and brain tissue, while cadmium was only measured in kidneys and averaged 0.22 μg g -1 . All element concentrations are presented on a wet weight basis. Concentrations of total mercury in all tissues were significantly higher in female than male mink, possibly reflecting proportionally greater food consumption by the smaller females. Total mercury concentrations were inversely related to the proportion of mercury present as methylmercury, and positively related to concentrations of selenium, consistent with increasing demethylation of methylmercury, and the formation of mercuric selenide as total concentrations of mercury increased. This relationship was seen most strongly in mink liver, less so in kidneys and not at all in brains where most of the mercury was maintained in the methyl form. There did not appear to be any geographical areas in which mink had obviously higher concentrations of mercury, and there was frequently a relatively large range of mercury levels found in mink from a given trapline. Mink diet may be a factor in this variation. Local environmental levels of cadmium were not reflected in cadmium concentrations in mink tissues. Mercury, cadmium and selenium do not appear to constitute environmental hazards to mink in the Yukon

MEASUREMENT OF MECURY IN FISH SCALES AS AN ASSESSMENT METHOD FOR PREDICTING MUSCLE TISSUE MERCURY CNOCENTRATIONS IN LARGEMOUTH BASS

Science.gov (United States)

The relationship between total mercury (Hg) concentration in fish scales and in tissues of largemouth bass (Micropterus salmoides) from 20 freshwater sites was developed and evaluated to determine whether scale analysis would allow a non lethal and convenient method for predicti...

Summary of total mercury concentrations in fillets of selected sport fishes collected during 2000-2003 from Lake Natoma, Sacramento County, California

Science.gov (United States)

Saiki, Michael K.; Slotton, Darrell G.; May, Thomas W.; Ayers, Shaun M.; Alpers, Charles N.

2004-01-01

This report summarizes results of total mercury measurements in skinless fillets of sport fishes collected during August 2000, September?October 2002, and July 2003 from Lake Natoma, a small (8,760 acre-feet) afterbay for Folsom Dam on the lower American River. The primary objective of the study was to determine if mercury concentrations in fillets approached or exceeded guidelines for human consumption. The Food and Drug Administration (FDA) human-health action level for methylmercury in commercially caught fish is 1.0 ?g/g (microgram per gram); the U.S. Environmental Protection Agency (USEPA) human-health criterion for methylmercury residue in fish tissue is 0.30 ?g/g. Wet weight concentrations of total mercury in skinless fillets were as high as 0.19 ?g/g in bluegill (Lepomis macrochirus), 0.39 ?g/g in redear sunfish (L. microlophus), 1.02 ?g/g in largemouth bass (Micropterus salmoides), and 1.89 ?g/g in channel catfish (Ictalurus punctatus). Maximum concentrations of mercury in other fish species varied from 0.10 ?g/g in rainbow trout (Oncorhynchus mykiss) to 0.56 ?g/g in white catfish (A-meiurus catus). Altogether, 1 of 86 largemouth bass and 11 of 11 channel catfish exceeded the FDA human-health action level. In addition, 1 of 20 redear sunfish, 26 of 86 largemouth bass, 2 of 3 spotted bass (M. punctulatus), 1 of 1 brown bullhead (A. nebulosus), and 1 of 1 white catfish exceeded the USEPA human-health criterion. These results indicate that some fish species inhabiting Lake Natoma contain undesirably high concentrations of mercury in their skinless fillets.

Use of cover habitat by bull trout Salvelinus confluentus and lake trout Salvelinus namaycush in a laboratory environment

Science.gov (United States)

Meeuwig, Michael H.; Guy, Christopher S.; Fredenberg, Wade A.

2011-01-01

Lacustrine-adfluvial bull trout, Salvelinus confluentus, migrate from spawning and rearing streams to lacustrine environments as early as age 0. Within lacustrine environments, cover habitat pro- vides refuge from potential predators and is a resource that is competed for if limiting. Competitive inter- actions between bull trout and other species could result in bull trout being displaced from cover habitat, and bull trout may lack evolutionary adaptations to compete with introduced species, such as lake trout, Salvelinus namaycush. A laboratory experiment was performed to examine habitat use and interactions for cover by juvenile (i.e., habitat, with bull trout using cover and bottom habitats more than lake trout. Habitat selection ratios indicated that bull trout avoided water column habitat in the presence of lake trout and that lake trout avoided bottom habitat. Intraspecific and interspecific agonistic interactions were infrequent, but approximately 10 times greater for intraspecific inter- actions between lake trout. Results from this study provide little evidence that juvenile bull trout and lake trout compete for cover, and that species-specific differences in habitat use and selection likely result in habitat partitioning between these species.

Mercury accumulation plant Cyrtomium macrophyllum and its potential for phytoremediation of mercury polluted sites.

Science.gov (United States)

Xun, Yu; Feng, Liu; Li, Youdan; Dong, Haochen

2017-12-01

Cyrtomium macrophyllum naturally grown in 225.73 mg kg -1 of soil mercury in mining area was found to be a potential mercury accumulator plant with the translocation factor of 2.62 and the high mercury concentration of 36.44 mg kg -1 accumulated in its aerial parts. Pot experiments indicated that Cyrtomium macrophyllum could even grow in 500 mg kg -1 of soil mercury with observed inhibition on growth but no obvious toxic effects, and showed excellent mercury accumulation and translocation abilities with both translocation and bioconcentration factors greater than 1 when exposed to 200 mg kg -1 and lower soil mercury, indicating that it could be considered as a great mercury accumulating species. Furthermore, the leaf tissue of Cyrtomium macrophyllum showed high resistance to mercury stress because of both the increased superoxide dismutase activity and the accumulation of glutathione and proline induced by mercury stress, which favorited mercury translocation from the roots to the aerial parts, revealing the possible reason for Cyrtomium macrophyllum to tolerate high concentration of soil mercury. In sum, due to its excellent mercury accumulation and translocation abilities as well as its high resistance to mercury stress, the use of Cyrtomium macrophyllum should be a promising approach to remediating mercury polluted soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cutaneous mercury granuloma

OpenAIRE

Kalpana A Bothale; Sadhana D Mahore; Sushil Pande; Trupti Dongre

2013-01-01

Cutaneous mercury granuloma is rarely encountered. Clinically it may pose difficulty in diagnosis. Here, we report a 23-year-old male presented with erythematous, nodular lesions over the forearm and anterior aspect of chest wall. Metallic mercury in tissue sections appear as dark black, opaque, spherical globules of varying size and number. They are surrounded by granulomatous foreign-body reaction. It is composed of foreign body giant cells and mixed inflammatory infiltrate composed of hist...

Diagnostic single nucleotide polymorphisms for identifying westslope cutthroat trout (Oncorhynchus clarki lewisi), Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri) and rainbow trout (Oncorhynchus mykiss).

Science.gov (United States)

Kalinowski, S T; Novak, B J; Drinan, D P; Jennings, R deM; Vu, N V

2011-03-01

We describe 12 diagnostic single nucleotide polymorphism (SNP) assays for use in species identification among rainbow and cutthroat trout: five of these loci have alleles unique to rainbow trout (Oncorhynchus mykiss), three unique to westslope cutthroat trout (O. clarkii lewisi) and four unique to Yellowstone cutthroat trout (O. clarkii bouvieri). These diagnostic assays were identified using a total of 489 individuals from 26 populations and five fish hatchery strains. © 2010 Blackwell Publishing Ltd.

Solid phase microextraction capillary gas chromatography combined with furnace atomization plasma emission spectrometry for speciation of mercury in fish tissues

International Nuclear Information System (INIS)

Grinberg, Patricia; Campos, Reinaldo C.; Mester, Zoltan; Sturgeon, Ralph E.

2003-01-01

The use of solid phase microextraction in conjunction with tandem gas chromatography-furnace atomization plasma emission spectrometry (SPME-GC-FAPES) was evaluated for the determination of methylmercury and inorganic mercury in fish tissue. Samples were digested with methanolic potassium hydroxide, derivatized with sodium tetraethylborate and extracted by SPME. After the SPME extraction, species were separated by GC and detected by FAPES. All experimental parameters were optimized for best separation and analytical response. A repeatability precision of typically 2% can be achieved with long-term (3 months) reproducibility precision of 4.3%. Certified Reference Materials DORM-2, DOLT-2 and TORT-2 from the National Research Council of Canada were analyzed to verify the accuracy of this technique. Detection limits of 1.5 ng g -1 for methylmercury and 0.7 ng g -1 for inorganic mercury in biological tissues were obtained

Contribution of cathepsins B, L and D to muscle protein profiles correlated with texture in rainbow trout (Oncorhynchus mykiss)

DEFF Research Database (Denmark)

Godiksen, Helene; Morzel, M.; Hyldig, Grethe

2009-01-01

Post-mortem softening of fish tissue often results in low yield and decreased product quality. In this study, proteolytic profiles of trout stored 5 days oil ice were obtained by SDS-PAGE. The link between protein hand intensities and firmness of trout fillets was examined through a correlation...

Metallothionein in brook trout (salvelinus fontinalis) as a biological indicator of inorganic chemical contaminant stress

International Nuclear Information System (INIS)

Hamilton, S.J.

1985-01-01

A technique for quantifying metallothionein was evaluated with fish tissue. Adult brook trout were administered 3 mg 109 cadmium/kg body weight by intraperitoneal injection over a 5 day period to induce metallothionein concentrations in liver and kidney tissues. The method was modified so cadmium bound to unsaturated metallothionein could be measured. The method gave precise measurements and was used to evaluate the toxicological significant of metallothionein in two 30-day chronic toxicity studies of cadmium on brook trout. In particular, metallothionein was evaluated as a biological indicator of inorganic chemical stress in brook trout. Pathological effects in animals resulting from exposure to inorganic chemicals is thought to occur when metallothionein's sequestering ability is exceeded; a phenomenon explained by the spillover hypothesis. The presence of free cadmium in tissues of fish from all exposures suggests metallothionein was not saturated with cadmium perhaps because of competition for binding sites on metallothionein between cadmium and other inorganic chemicals such as copper and zinc. Based on results of the two toxicity studies, the spillover hypothesis should be redefined to a continuum of toxic responses to varying balances between the relative abundance of inorganic chemicals present and their respective binding affinities for metallothionein

BIOACCUMULATION AND ENANTIOSELECTIVE BIOTRANSFORMATION OF FIPRONIL BY RAINBOW TROUT (ONCORHYNCHUS MYKISS)

Science.gov (United States)

Dietary accumulation and enantioselective biotransformation was determined for rainbow trout (Oncorhynchus mykiss) exposed to fipronil, a widely used chiral pesticide. Measurement of the fish carcass tissue (whole fish minus GI tract and liver) showed a rapid accumulation of fip...

From tails to toes: developing nonlethal tissue indicators of mercury exposure in five amphibian species.

Science.gov (United States)

Pfleeger, Adam Z; Eagles-Smith, Collin A; Kowalski, Brandon M; Herring, Garth; Willacker, James J; Jackson, Allyson K; Pierce, John R

2016-04-01

Exposure to environmental contaminants has been implicated as a factor in global amphibian decline. Mercury (Hg) is a particularly widespread contaminant that biomagnifies in amphibians and can cause a suite of deleterious effects. However, monitoring contaminant exposure in amphibian tissues may conflict with conservation goals if lethal take is required. Thus, there is a need to develop non-lethal tissue sampling techniques to quantify contaminant exposure in amphibians. Some minimally invasive sampling techniques, such as toe-clipping, are common in population-genetic research, but it is unclear if these methods can adequately characterize contaminant exposure. We examined the relationships between mercury (Hg) concentrations in non-lethally sampled tissues and paired whole-bodies in five amphibian species. Specifically, we examined the utility of three different tail-clip sections from four salamander species and toe-clips from one anuran species. Both tail and toe-clips accurately predicted whole-body THg concentrations, but the relationships differed among species and the specific tail-clip section or toe that was used. Tail-clips comprised of the distal 0-2 cm segment performed the best across all salamander species, explaining between 82 and 92% of the variation in paired whole-body THg concentrations. Toe-clips were less effective predictors of frog THg concentrations, but THg concentrations in outer rear toes accounted for up to 79% of the variability in frog whole-body THg concentrations. These findings suggest non-lethal sampling of tails and toes has potential applications for monitoring contaminant exposure and risk in amphibians, but care must be taken to ensure consistent collection and interpretation of samples.

Diel resource partitioning among juvenile Atlantic Salmon, Brown Trout, and Rainbow Trout during summer

Science.gov (United States)

Johnson, James H.; McKenna, James E.

2015-01-01

Interspecific partitioning of food and habitat resources has been widely studied in stream salmonids. Most studies have examined resource partitioning between two native species or between a native species and one that has been introduced. In this study we examine the diel feeding ecology and habitat use of three species of juvenile salmonids (i.e., Atlantic Salmon Salmo salar, Brown Trout Salmo trutta, and Rainbow Trout Oncorhynchus mykiss) in a tributary of Skaneateles Lake, New York. Subyearling Brown Trout and Rainbow Trout fed more heavily from the drift than the benthos, whereas subyearling Atlantic Salmon fed more from the benthos than either species of trout. Feeding activity of Atlantic Salmon and Rainbow Trout was similar, with both species increasing feeding at dusk, whereas Brown Trout had no discernable feeding peak or trough. Habitat availability was important in determining site-specific habitat use by juvenile salmonids. Habitat selection was greater during the day than at night. The intrastream, diel, intraspecific, and interspecific variation we observed in salmonid habitat use in Grout Brook illustrates the difficulty of acquiring habitat use information for widespread management applications.

Mercury and Methylmercury Concentrations in Muscle Tissue of Fish Caught in Major Rivers of the Czech Republic

Directory of Open Access Journals (Sweden)

K. Kružíková

2008-01-01

Full Text Available The aim of the study was to evaluate mercury contamination at twelve outlet sites of rivers in the Czech Republic (Labe, Ohře, Vltava, Berounka, Sázava, Otava, Lužnice, Svratka, Dyje, Morava and Odra. As an indicator, we used muscle tissue of the chub (Leuciscus cephalus caught at selected sites in 2007. A total of 96 fish were examined. Total mercury was determined by atomic absorption spectrophotometry using the AMA 254 analyzer and methylmercury was determined by gas chromatography with electron-capture detection. Total mercury (THg and methylmercury (MeHg concentrations ranged 0.039–0.384 mg kg-1 fresh weight and 0.033–0.362 mg kg-1 fresh weight, respectively. Mercury bound in methylmercury (HgMe made up on average about 82.2% of total mercury. The highest mercury concentrations were found in fish from Obříství, a site on Labe (THg 0.263 ± 0.086 mg kg-1; MeHg 0.256 ± 0.084 mg kg-1. Mercury concentrations in fish from rivers that cross the borders of the Czech Republic (Labe, Odra and Morava were low. The Czech Republic therefore does not contribute significantly to river pollution outside its national borders. Hazard indices of the sites monitored were well below 1, and reached 1.365 only in Obříství on Labe for fisherman’s family members (i.e. in the case of annual consumption of 10 kg fish. This indicates possible hazards involved in eating meat of fish caught in that location. Based on PTWI for methylmercury, the maximum amount of fish meat allowed for consumption per week was calculated. The site with the lowest value was Obříství on Labe (0.44 kg. The results of this study present a partial contribution to health risk assessment on the major rivers in Czech Republic.

Tetracapsuloides bryosalmonae persists in brown trout Salmo trutta for five years post exposure.

Science.gov (United States)

Soliman, Hatem; Kumar, Gokhlesh; El-Matbouli, Mansour

2018-01-31

Tetracapsuloides bryosalmonae is a malacosporean parasite and the causative agent of proliferative kidney disease (PKD) that seriously impacts farmed and wild salmonids. The parasite's life cycle includes an invertebrate host, the bryozoan Fredericella sultana, and a vertebrate host, salmonid fish. The persistence of T. bryosalmonae in brown trout Salmo trutta for up to 2 yr following exposure is well documented. Results from the present study confirmed that one brown trout that had recovered from PKD did not completely clear the parasite from its tissues and that T. bryosalmonae could persist in brown trout for up to 5 yr post exposure. Furthermore, recovered infected brown trout can release viable T. bryosalmonae spores that are able to infect specific pathogen-free F. sultana colonies. T. bryosalmonae DNA was detected by PCR in every organ, and parasite stages were observed in the kidney, spleen and liver following immunohistochemistry. This finding indicates that T. bryosalmonae-infected brown trout can act as asymptomatic carriers and release the parasite for several years after the initial infection, acting as a reservoir of infection, and contributing to the dissemination of the parasite to new areas.

Functional Identification of Dendritic Cells in the Teleost Model, Rainbow Trout (Oncorhynchus mykiss)

Science.gov (United States)

Bassity, Elizabeth; Clark, Theodore G.

2012-01-01

Dendritic cells are specialized antigen presenting cells that bridge innate and adaptive immunity in mammals. This link between the ancient innate immune system and the more evolutionarily recent adaptive immune system is of particular interest in fish, the oldest vertebrates to have both innate and adaptive immunity. It is unknown whether dendritic cells co-evolved with the adaptive response, or if the connection between innate and adaptive immunity relied on a fundamentally different cell type early in evolution. We approached this question using the teleost model organism, rainbow trout (Oncorhynchus mykiss), with the aim of identifying dendritic cells based on their ability to stimulate naïve T cells. Adapting mammalian protocols for the generation of dendritic cells, we established a method of culturing highly motile, non-adherent cells from trout hematopoietic tissue that had irregular membrane processes and expressed surface MHCII. When side-by-side mixed leukocyte reactions were performed, these cells stimulated greater proliferation than B cells or macrophages, demonstrating their specialized ability to present antigen and therefore their functional homology to mammalian dendritic cells. Trout dendritic cells were then further analyzed to determine if they exhibited other features of mammalian dendritic cells. Trout dendritic cells were found to have many of the hallmarks of mammalian DCs including tree-like morphology, the expression of dendritic cell markers, the ability to phagocytose small particles, activation by toll-like receptor-ligands, and the ability to migrate in vivo. As in mammals, trout dendritic cells could be isolated directly from the spleen, or larger numbers could be derived from hematopoietic tissue and peripheral blood mononuclear cells in vitro. PMID:22427987

Distribution of mercury in guinea pig offspring after in utero exposure to mercury vapor during late gestation

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Minoru; Yamamura, Yukio; Sataoh, Hiroshi

1986-04-01

Organ distribution of mercury after in utero mercury vapor exposure was investigated in neonatal guinea pigs. Mother guinea pigs in late gestation were exposed to 0.2-0.3 mg/m/sup 3/ mercury vapor 2 h per day until giving birth. Mercury concentrations in neonatal brain, lungs, heart, kidneys, plasma and erythrocytes were much lower than those of maternal organs and tissues. Neonatal liver, however, showed a mercury concentration twice as high as maternal liver. Mercury concentration ratios of erythrocytes to plasma in offspring were quite different from those of mothers, being 0.2-0.4 for offspring, and 1.3-3.0 for mothers. These results suggested that mercury vapor metabolism in fetuses was quite different from that in their mothers. This may be due to the different blood circulation, as mercury vapor transferred through the placental barrier would be rapidly oxidized into ionic mercury in fetal liver and accumulated in the organ. The different mercury vapor metabolism may prevent fetal brain, which is rapidly developing, and thus vulnerable, from being exposed to excessive mercury vapor.

Does the introduced brook trout ( Salvelinus fontinalis) affect growth of the native brown trout ( Salmo trutta)?

Science.gov (United States)

Korsu, Kai; Huusko, Ari; Muotka, Timo

2009-03-01

Non-native brook trout have become widely established in North European streams. We combined evidence from an artificial-stream experiment and drainage-scale field surveys to examine whether brook trout suppressed the growth of the native brown trout (age 0 to age 2). Our experimental results demonstrated that brown trout were unaffected by the presence of brook trout but that brook trout showed reduced growth in the presence of brown trout. However, the growth reduction only appeared in the experimental setting, indicating that the reduced spatial constraint of the experimental system may have forced the fish to unnaturally intense interactions. Indeed, in the field, no effect of either species on the growth of the putative competitor was detected. These results caution against uncritical acceptance of findings from small-scale experiments because they rarely scale up to more complex field situations. This and earlier work suggest that the establishment of brook trout in North European streams has taken place mainly because of the availability of unoccupied (or underutilized) niche space, rather than as a result of species trait combinations or interspecific competition per se.

Marcellus and mercury: Assessing potential impacts of unconventional natural gas extraction on aquatic ecosystems in northwestern Pennsylvania.

Science.gov (United States)

Grant, Christopher J; Weimer, Alexander B; Marks, Nicole K; Perow, Elliott S; Oster, Jacob M; Brubaker, Kristen M; Trexler, Ryan V; Solomon, Caroline M; Lamendella, Regina

2015-01-01

Mercury (Hg) is a persistent element in the environment that has the ability to bioaccumulate and biomagnify up the food chain with potentially harmful effects on ecosystems and human health. Twenty-four streams remotely located in forested watersheds in northwestern PA containing naturally reproducing Salvelinus fontinalis (brook trout), were targeted to gain a better understanding of how Marcellus shale natural gas exploration may be impacting water quality, aquatic biodiversity, and Hg bioaccumulation in aquatic ecosystems. During the summer of 2012, stream water, stream bed sediments, aquatic mosses, macroinvertebrates, crayfish, brook trout, and microbial samples were collected. All streams either had experienced hydraulic fracturing (fracked, n = 14) or not yet experienced hydraulic fracturing (non-fracked, n = 10) within their watersheds at the time of sampling. Analysis of watershed characteristics (GIS) for fracked vs non-fracked sites showed no significant differences (P > 0.05), justifying comparisons between groups. Results showed significantly higher dissolved total mercury (FTHg) in stream water (P = 0.007), lower pH (P = 0.033), and higher dissolved organic matter (P = 0.001) at fracked sites. Total mercury (THg) concentrations in crayfish (P = 0.01), macroinvertebrates (P = 0.089), and predatory macroinvertebrates (P = 0.039) were observed to be higher for fracked sites. A number of positive correlations between amount of well pads within a watershed and THg in crayfish (r = 0.76, P shale natural gas exploration is having an effect on aquatic ecosystems.

Role of bacteria in bioaccumulation of mercury in the oyster Crassostrea virginica

International Nuclear Information System (INIS)

Sayler, G.S.; Nelson, J.D. Jr.; Colwell, R.R.

1975-01-01

An investigation of mercury-resistant bacteria was undertaken to determine their role in the accumulation of mercury in a simplified food chain. Oysters (Crassostrea virginica) were maintained in a closed system, sealed aquarium with stirred, aerated water containing 10 μg of 203 HgCl 2 per liter. Uptake of 203 Hg by oysters held under control conditions was compared with that of 203 Hg uptake by oysters under similar conditions except that mercury-accumulating and mercury-metabolizing species of Pseudomonsa, isolated from Chesapeake Bay, were added to the experimental oysters. After incubation for 4 days, the major portion of the 203 Hg in the water column was found to be associated with the microparticulate fraction, corresponding to a rise in total viable count. Mercury accumulation in the oysters was significantly higher in the gill and fisceral tissue than other tissues. Mercury concentrations were 200 times greater in tissue fractions of oysters dosed with mercury-metabolizing bacteria compared with the oysters held under control conditions without mercury-metabolizing bacteria. (U.S.)

The release of bystander factor(s) from tissue explant cultures of rainbow trout (Onchorhynchus mykiss) after exposure to gamma radiation.

Science.gov (United States)

O'Dowd, Colm; Mothersill, Carmel E; Cairns, Michael T; Austin, Brian; McClean, Brendan; Lyng, Fiona M; Murphy, James E J

2006-10-01

The bystander response has been documented in cell lines and cell cultures derived from aquatic species over the past several years. However, little work has been undertaken to identify a similar bystander response in tissue explant cultures from fish. In this study, indirect effects of ionizing gamma radiation on tissue explant cultures of fish were investigated. Tissue explants in culture were exposed to 0.5 Gy and 5 Gy gamma radiation from a 60Co teletherapy unit. A bystander response in Epithelioma papulosum cyprini (EPC) cells exposed to gamma-irradiated tissue conditioned medium from rainbow trout explants was investigated, and the effects on cell survival were quantified by the clonogenic survival assay. Dichlorofluorescein and rhodamine 123 fluorescent dyes were used to identify alterations in reactive oxygen species (ROS) and mitochondrial membrane potential (MMP), respectively. Results indicate a different response for the three tissue types investigated. Clonogenic assay results vary from a decrease in cell survival (gill) to no effect (skin) to a stimulatory effect (spleen). Results from fluorescence assays of ROS and MMP show similarities to clonogenic assay results. This study identifies a useful model for further studies relating to the bystander effect in aquatic organisms in vivo and ex vivo.

Scale-dependent seasonal pool habitat use by sympatric Wild Brook Trout and Brown Trout populations

Science.gov (United States)

Davis, Lori A.; Wagner, Tyler

2016-01-01

Sympatric populations of native Brook Trout Salvelinus fontinalis and naturalized Brown Trout Salmo truttaexist throughout the eastern USA. An understanding of habitat use by sympatric populations is of importance for fisheries management agencies because of the close association between habitat and population dynamics. Moreover, habitat use by stream-dwelling salmonids may be further complicated by several factors, including the potential for fish to display scale-dependent habitat use. Discrete-choice models were used to (1) evaluate fall and early winter daytime habitat use by sympatric Brook Trout and Brown Trout populations based on available residual pool habitat within a stream network and (2) assess the sensitivity of inferred habitat use to changes in the spatial scale of the assumed available habitat. Trout exhibited an overall preference for pool habitats over nonpool habitats; however, the use of pools was nonlinear over time. Brook Trout displayed a greater preference for deep residual pool habitats than for shallow pool and nonpool habitats, whereas Brown Trout selected for all pool habitat categories similarly. Habitat use by both species was found to be scale dependent. At the smallest spatial scale (50 m), habitat use was primarily related to the time of year and fish weight. However, at larger spatial scales (250 and 450 m), habitat use varied over time according to the study stream in which a fish was located. Scale-dependent relationships in seasonal habitat use by Brook Trout and Brown Trout highlight the importance of considering scale when attempting to make inferences about habitat use; fisheries managers may want to consider identifying the appropriate spatial scale when devising actions to restore and protect Brook Trout populations and their habitats.

Thermal regimes, nonnative trout, and their influences on native Bull Trout in the Upper Klamath River Basin, Oregon

Science.gov (United States)

Benjamin, Joseph R.; Heltzel, Jeannie; Dunham, Jason B.; Heck, Michael; Banish, Nolan P.

2016-01-01

The occurrence of fish species may be strongly influenced by a stream’s thermal regime (magnitude, frequency, variation, and timing). For instance, magnitude and frequency provide information about sublethal temperatures, variability in temperature can affect behavioral thermoregulation and bioenergetics, and timing of thermal events may cue life history events, such as spawning and migration. We explored the relationship between thermal regimes and the occurrences of native Bull Trout Salvelinus confluentus and nonnative Brook Trout Salvelinus fontinalis and Brown Trout Salmo trutta across 87 sites in the upper Klamath River basin, Oregon. Our objectives were to associate descriptors of the thermal regime with trout occurrence, predict the probability of Bull Trout occurrence, and estimate upper thermal tolerances of the trout species. We found that each species was associated with a different suite of thermal regime descriptors. Bull Trout were present at sites that were cooler, had fewer high-temperature events, had less variability, and took longer to warm. Brook Trout were also observed at cooler sites with fewer high-temperature events, but the sites were more variable and Brook Trout occurrence was not associated with a timing descriptor. In contrast, Brown Trout were present at sites that were warmer and reached higher temperatures faster, but they were not associated with frequency or variability descriptors. Among the descriptors considered, magnitude (specifically June degree-days) was the most important in predicting the probability of Bull Trout occurrence, and model predictions were strengthened by including Brook Trout occurrence. Last, all three trout species exhibited contrasting patterns of tolerating longer exposures to lower temperatures. Tolerance limits for Bull Trout were lower than those for Brook Trout and Brown Trout, with contrasts especially evident for thermal maxima. Our results confirm the value of exploring a suite of thermal

Influences on Mercury Bioaccumulation Factors for the Savannah River

International Nuclear Information System (INIS)

Paller, M.H.

2003-01-01

Mercury TMDLs (Total Maximum Daily Loads) are a regulatory instrument designed to reduce the amount of mercury entering a water body and ultimately to control the bioaccumulation of mercury in fish. TMDLs are based on a BAF (bioaccumulation factor), which is the ratio of methyl mercury in fish to dissolved methyl mercury in water. Analysis of fish tissue and aqueous methyl mercury samples collected at a number of locations and over several seasons in a 118 km reach of the Savannah River demonstrated that species specific BAFs varied by factors of three to eight. Factors contributing to BAF variability were location, habitat and season related differences in fish muscle tissue mercury levels and seasonal differences in dissolved methyl mercury levels. Overall (all locations, habitats, and seasons) average BAFs were 3.7 x 106 for largemouth bass, 1.4 x 106 for sunfishes, and 2.5 x 106 for white catfish. Inaccurate and imprecise BAFs can result in unnecessary economic impact or insufficient protection of human health. Determination of representative and precise BAFs for mercury in fish FR-om large rivers necessitates collecting large and approximately equal numbers of fish and aqueous methyl mercury samples over a seasonal cycle FR-om the entire area and all habitats to be represented by the TMDL

Mechanisms of fenthion activation in rainbow trout (Oncorhynchus mykiss) acclimated to hypersaline environments

International Nuclear Information System (INIS)

Lavado, Ramon; Rimoldi, John M.; Schlenk, Daniel

2009-01-01

Previous studies in rainbow trout have shown that acclimation to hypersaline environments enhances the toxicity to thioether organophosphate and carbamate pesticides. In order to determine the role of biotransformation in this process, the metabolism of the thioether organophosphate biocide, fenthion was evaluated in microsomes from gills, liver and olfactory tissues in rainbow trout (Oncorhynchus mykiss) acclimated to freshwater and 17 per mille salinity. Hypersalinity acclimation increased the formation of fenoxon and fenoxon sulfoxide from fenthion in liver microsomes from rainbow trout, but not in gills or in olfactory tissues. NADPH-dependent and independent hydrolysis was observed in all tissues, but only NADPH-dependent fenthion cleavage was differentially modulated by hypersalinity in liver (inhibited) and gills (induced). Enantiomers of fenthion sulfoxide (65% and 35% R- and S-fenthion sulfoxide, respectively) were formed in liver and gills. The predominant pathway of fenthion activation in freshwater appears to be initiated through initial formation of fenoxon which may be subsequently converted to the most toxic metabolite fenoxon R-sulfoxide. However, in hypersaline conditions both fenoxon and fenthion sulfoxide formation may precede fenoxon sulfoxide formation. Stereochemical evaluation of sulfoxide formation, cytochrome P450 inhibition studies with ketoconazole and immunoblots indicated that CYP3A27 was primarily involved in the enhancement of fenthion activation in hypersaline-acclimated fish with limited contribution of FMO to initial sulfoxidation

Temporary Restoration of Bull Trout Passage at Albeni Falls Dam

Energy Technology Data Exchange (ETDEWEB)

Paluch, Mark; Scholz, Allan; McLellan, Holly [Eastern Washington University Department of Biology; Olson, Jason [Kalispel Tribe of Indians Natural Resources Department

2009-07-13

This study was designed to monitor movements of bull trout that were provided passage above Albeni Falls Dam, Pend Oreille River. Electrofishing and angling were used to collect bull trout below the dam. Tissue samples were collected from each bull trout and sent to the U. S. Fish and Wildlife Service Abernathy Fish Technology Center Conservation Genetics Lab, Washington. The DNA extracted from tissue samples were compared to a catalog of bull trout population DNA from the Priest River drainage, Lake Pend Oreille tributaries, and the Clark Fork drainage to determine the most probable tributary of origin. A combined acoustic radio or radio tag was implanted in each fish prior to being transported and released above the dam. Bull trout relocated above the dam were able to volitionally migrate into their natal tributary, drop back downstream, or migrate upstream to the next dam. A combination of stationary radio receiving stations and tracking via aircraft, boat, and vehicle were used to monitor the movement of tagged fish to determine if the spawning tributary it selected matched the tributary assigned from the genetic analysis. Seven bull trout were captured during electrofishing surveys in 2008. Of these seven, four were tagged and relocated above the dam. Two were tagged and left below the dam as part of a study monitoring movements below the dam. One was immature and too small at the time of capture to implant a tracking tag. All four fish released above the dam passed by stationary receivers stations leading into Lake Pend Oreille and no fish dropped back below the dam. One of the radio tags was recovered in the tributary corresponding with the results of the genetic test. Another fish was located in the vicinity of its assigned tributary, which was impassable due to low water discharge at its mouth. Two fish have not been located since entering the lake. Of these fish, one was immature and not expected to enter its natal tributary in the fall of 2008. The other

Australian seafood compositional profiles: A pilot study. Vitamin D and mercury content.

Science.gov (United States)

Padula, David; Greenfield, Heather; Cunningham, Judy; Kiermeier, Andreas; McLeod, Catherine

2016-02-15

Given the scarcity of comprehensive nutritional data for Australia's >400 commercially produced seafood species a pilot study was undertaken to collect and analyse 22 species of wild and aquaculture seafood in order to develop a model for future comprehensive surveys. The species analysed were: Atlantic salmon, Australian sardine, prawn (six species), barramundi, abalone (three species), blue sprat, burrowing blackfish, gummy shark, oyster (four species), ocean trout and yellowtail kingfish. The analyses undertaken in this pilot study were: moisture, protein, total fat, cholesterol, fatty acids, vitamin C, vitamins A and D, and 21 mineral elements (including total mercury and methyl mercury). The data reported here are for vitamin D and mercury only. Comprehensive data have already been published elsewhere. Issues identified that should be addressed prior to undertaking a more extensive and representative study of the remaining major edible commercial Australian seafood species include: choice of samples and nutrients for analysis, facilities for sample handling and storage, data management and scrutiny, and laboratory quality control. Copyright © 2014 Elsevier Ltd. All rights reserved.

Uptake of mercury from water by the grass shrimp, Palaemonetes vulgaris (Say)

International Nuclear Information System (INIS)

Ray, G.L.; Tripp, M.R.

1976-01-01

In order to assess the toxicity of mercury to the grass shrimp (Palaemonetes vulgaris [Say]), the lethal concentration for 50 percent (LC 50 ) of the tested population in a 24-hour period for HgCl 2 and MeHgCl were determined. The LC 50 values were approximately 400 parts per billion (ppB) Hg for HgCl 2 and 125 ppB Hg for MeHgCl. When shrimp were held in mercury solutions at sublethal concentrations (1.5 ppB Hg as HgCl 2 ) for 15 days, a maximum of 500 ppB Hg was accumulated in the animal's tissues after 3 days. The average tissue concentration of mercury for the remaining 12 days was 450 ppB Hg. The actual tissue distribution of mercury was determined by exposure of shrimp to radioactively labeled HgCl 2 and MeHgCl. No difference could be found in the tissue distribution of the two compounds. A significant difference is tissue mercury distribution occurred between the 24-hour and 72-hour exposures

The effects of varied densities on the growth and emigration of adult cutthroat trout and brook trout in fenced stream enclosures

Science.gov (United States)

Buys, D.J.; Hilderbrand, R.H.; Kershner, J.L.

2009-01-01

We evaluated the effects of various density treatments on adult fish growth and emigration rates between Bonneville cutthroat trout Oncorhynchus clarki utah and brook trout Salvelinus fontinalis in stream enclosures in Beaver Creek, Idaho, We used 3 density treatments (low, ambient, and high fish densities) to evaluate density-related effects and to ensure a response. Intraspecific ambient-density tests using cutthroat trout only were also performed. Results indicated an absence of cage effects in the stream enclosures and no differences in fish growth between ambient-density stream-enclosure fish and free-range fish. Brook trout outgrew and moved less than cutthroat trout in the stream enclosures, especially as density increased, In all 3 density treatments, brook trout gained more weight than cutthroat trout, with brook trout gaining weight in each density treatment and cutthroat trout losing weight at the highest density. At high densities, cutthroat trout attempted to emigrate more frequently than brook trout in sympatry and allopatry. We observed a negative correlation between growth and emigration for interspecific cutthroat trout, indicating a possible competitive response due to the presence of brook trout. We observed similar responses for weight and emigration in trials of allopatric cutthroat trout, indicating strong intraspecific effects as density increased. While cutthroat trout showed a response to experimental manipulation with brook trout at different densities, there has been long-term coexistence between these species in Beaver Creek, This system presents a unique opportunity to study the mechanisms that lead cutthroat trout to coexist with rather than be replaced by nonnative brook trout.

Mercury levels in eggs, embryos, and neonates of Trachemys callirostris (Testudines, Emydidae)

International Nuclear Information System (INIS)

Rendon Valencia, Beatriz; Zapata, Lina M; Bock, Brian C; Paez, Vivian P; Palacio, Jaime A.

2014-01-01

We quantified total mercury concentrations in eggshells, egg yolks, and embryos from 16 nests of the Colombian slider (Trachemys callirostris). Nests were collected in different stages of development, but estimated time of incubation in natural substrates was not correlated with mercury levels in the eggs, suggesting that mercury was not absorbed from the substrate, but more likely passed on to the embryos during folliculogenesis by the reproductive females who had bioaccumulated the mercury from environmental sources. Mean mercury concentrations were higher in embryos than in eggshells or egg yolks, indicating that embryos also bioaccumulate mercury present in other egg tissues. Intra-clutch variation in egg yolk mercury concentrations was relatively high. Egg yolk mercury concentrations were not associated with any of the fitness proxies we quantified for the nests (hatching success rates, initial neonate sizes and first-month juvenile growth rates). After five months of captive rearing in a mercury-free laboratory environment, 86 % of the juveniles had eliminated the mercury from their tissues.

JV Task 96 - Phase 2 - Investigating the Importance of the Mercury-Selenium Interaction

Energy Technology Data Exchange (ETDEWEB)

Nicholas Ralston; Laura Raymond

2008-03-01

In order to improve the understanding of the mercury issue, it is vital to study mercury's effects on selenium physiology. While mercury present in the environment or food sources may pose health risks, the protective effects of selenium have not been adequately considered in establishing regulatory policy. Numerous studies report that vulnerability to mercury toxicity is inversely proportional to selenium status or level. However, selenium status has not been considered in the development of the reference dosage levels for mercury exposure. Experimental animals fed low-selenium diets are far more vulnerable to mercury toxicity than animals fed normal selenium, and animals fed selenium-rich diets are even more resistant. Selenium-dependent enzymes in brain and endocrine tissues can be impaired by excessive mercury exposure, apparently because mercury has an extremely high binding affinity for selenium. When selenium becomes bound to mercury, it is unable to participate in the metabolic cycling of selenoprotein synthesis. Because of mercury-dependent impairments of selenoprotein synthesis, various antioxidant and regulatory functions in brain biochemistry are compromised. This report details a 2-year multiclient-funded research program designed to examine the interactions between mercury and selenium in animal models. The studies explored the effects of dietary intakes of toxic amounts of methylmercury and the protective effects of the normal dietary range of selenium in counteracting mercury toxicity. This study finds that the amounts of selenium present in ocean fish are sufficient to protect against far larger quantities of methylmercury than those present in typical seafoods. Toxic effects of methylmercury exposure were not directly proportional to mercury concentrations in blood, brain, or any other tissues. Instead, mercury toxicity was proportional to molar ratios of mercury relative to selenium. In order to accurately assess risk associated with

Landscape-scale evaluation of asymmetric interactions between Brown Trout and Brook Trout using two-species occupancy models

Science.gov (United States)

Wagner, Tyler; Jefferson T. Deweber,; Jason Detar,; John A. Sweka,

2013-01-01

Predicting the distribution of native stream fishes is fundamental to the management and conservation of many species. Modeling species distributions often consists of quantifying relationships between species occurrence and abundance data at known locations with environmental data at those locations. However, it is well documented that native stream fish distributions can be altered as a result of asymmetric interactions between dominant exotic and subordinate native species. For example, the naturalized exotic Brown Trout Salmo trutta has been identified as a threat to native Brook Trout Salvelinus fontinalis in the eastern United States. To evaluate large-scale patterns of co-occurrence and to quantify the potential effects of Brown Trout presence on Brook Trout occupancy, we used data from 624 stream sites to fit two-species occupancy models. These models assumed that asymmetric interactions occurred between the two species. In addition, we examined natural and anthropogenic landscape characteristics we hypothesized would be important predictors of occurrence of both species. Estimated occupancy for Brook Trout, from a co-occurrence model with no landscape covariates, at sites with Brown Trout present was substantially lower than sites where Brown Trout were absent. We also observed opposing patterns for Brook and Brown Trout occurrence in relation to percentage forest, impervious surface, and agriculture within the network catchment. Our results are consistent with other studies and suggest that alterations to the landscape, and specifically the transition from a forested catchment to one that contains impervious surface or agriculture, reduces the occurrence probability of wild Brook Trout. Our results, however, also suggest that the presence of Brown Trout results in lower occurrence probability of Brook Trout over a range of anthropogenic landscape characteristics, compared with streams where Brown Trout were absent.

The accumulation of radioactive caesium from water by the brown trout (Salmo trutta) and its comparison with plaice and rays

International Nuclear Information System (INIS)

Hewett, C.J.; Jefferies, D.F.

1976-01-01

The patterns of accumulation of caesium-137 from water by the tissues and organs of the freshwater teleost, the brown trout (Salmo trutta) are described. Estimates of the biological half-times and steady-state concentrations are derived, using a simple exponential equation. In all tissues and organs examined, other than muscle, the rate processes of the trout fall between those of the plaice and the ray. It is concluded that most of the caesium accumulated by the brown trout from water enters other than by the gut, probably through the gills, but as with plaice and ray, the main source of the caesium, possibly 90%, must come from the food. Despite differences in the levels of accumulation, the ratios of the tissue to blood steady state concentrations were very similar in all three species. The steady state caesium concentration of the blood appeared to be directly related to the red blood cell count of the fish. (author)

Cortisol regulates nitric oxide synthase in freshwater and seawater acclimated rainbow trout, Oncorhynchus mykiss

DEFF Research Database (Denmark)

Gerber, Lucie; Madsen, Steffen S; Jensen, Frank B

2017-01-01

Cortisol and nitric oxide (NO) are regulators of ion transport and metabolic functions in fish. In the gill, they show opposite effects on Na(+)/K(+)-ATPase (NKA) activity: cortisol stimulates NKA activity while NO inhibits NKA activity. We hypothesized that cortisol may impact NO production...... in osmoregulatory tissues by regulating NO synthase (NOS) expression. We evaluated the influence of cortisol treatment on mRNA expression of Nos1 and Nos2 in gill, kidney and middle intestine of both freshwater (FW) and seawater (SW) acclimated rainbow trout and found both tissue- and salinity-dependent effects....... Nos2 expression was down-regulated in the gill by cortisol injection in both FW and SW trout. This was substantiated by incubating gill tissue with cortisol ex vivo. Similarly, cortisol injection significantly down-regulated Nos2 expression in kidney of SW fish but not in FW fish. In the middle...

[Evaluation of the mercury accumulating capacity of pepper (Capsicum annuum)].

Science.gov (United States)

Pérez-Vargas, Híver M; Vidal-Durango, Jhon V; Marrugo-Negrete, José L

2014-01-01

To assess the mercury accumulating capacity in contaminated soils from the community of Mina Santa Cruz, in the south of the department of Bolívar, Colombia, of the pepper plant (Capsicum annuum), in order to establish the risk to the health of the consuming population. Samples were taken from tissues (roots, stems, and leaves) of pepper plants grown in two soils contaminated with mercury and a control soil during the first five months of growth to determine total mercury through cold vapor atomic absorption spectrometry. Total mercury was determined in the samples of pepper plant fruits consumed in Mina Santa Cruz. The mean concentrations of total mercury in the roots were higher than in stems and leaves. Accumulation in tissues was influenced by mercury levels in soil and the growth time of the plants. Mercury concentrations in fruits of pepper plant were lower than tolerable weekly intake provided by WHO. Percent of translocation of mercury to aerial parts of the plant were low in both control and contaminated soils. Despite low levels of mercury in this food, it is necessary to minimize the consumption of food contaminated with this metal.

Mercury pollution in Malaysia.

Science.gov (United States)

Hajeb, Parvaneh; Jinap, S; Ismail, Ahmad; Mahyudin, Nor Ainy

2012-01-01

Although several studies have been published on levels of mercury contamination of the environment, and of food and human tissues in Peninsular Malaysia, there is a serious dearth of research that has been performed in East Malaysia (Sabah and Sarawak). Industry is rapidly developing in East Malaysia, and, hence, there is a need for establishing baseline levels of mercury contamination in environmental media in that part of the country by performing monitoring studies. Residues of total mercury and inorganic in food samples have been determined in nearly all previous studies that have been conducted; however, few researchers have analyzed samples for the presence of methlymercury residues. Because methylmercury is the most toxic form of mercury, and because there is a growing public awareness of the risk posed by methylmercury exposure that is associated with fish and seafood consumption, further monitoring studies on methylmercury in food are also essential. From the results of previous studies, it is obvious that the economic development in Malaysia, in recent years, has affected the aquatic environment of the country. Primary areas of environmental concern are centered on the rivers of the west Peninsular Malaysian coast, and the coastal waters of the Straits of Malacca, wherein industrial activities are rapidly expanding. The sources of existing mercury input to both of these areas of Malaysia should be studied and identified. Considering the high levels of mercury that now exists in human tissues, efforts should be continued, and accelerated in the future, if possible, to monitor mercury contamination levels in the coastal states, and particularly along the west Peninsular Malaysian coast. Most studies that have been carried out on mercury residues in environmental samples are dated, having been conducted 20-30 years ago; therefore, the need to collect much more and more current data is urgent. Furthermore, establishing baseline levels of mercury exposure to

Use of wild trout for PBDE assessment in freshwater environments: Review and summary of critical factors

Directory of Open Access Journals (Sweden)

Juan M. Ríos

2015-11-01

Full Text Available Certain wild animals represent sentinels to address issues related to environmental pollution, since they can provide integrative data on both pollutant exposure and biological effects. Despite their technological benefits, PBDEs are considered a threat to environmental health due to their persistence, toxicity, and capacity to be accumulated. These pollutants have been found geographically widespread in fish, particularly in predator species such as trout. The aim of this work is to critically review the applicability and usefulness of wild trout for assessing PBDEs in freshwater environments. Reviewed reports include data from highly industrialized areas as well as areas from remote regions with relatively low human activity, including European and North American great lakes and freshwater environments in Europe, Greenland, subarctic areas and Patagonia, respectively. A summary of relevant factors were grouped into organism-specific factors (food habits, age, size, lipid content, sex and reproduction, tissue type, mechanism of contaminant uptake and metabolism, and PBDE levels in the surrounding environment (sediment. Five wild trout species [rainbow trout (Oncorhynchus mykiss, brown trout (Salmo trutta, lake trout (Salvelinus namaycush, arctic char (Salvelinus alpinus, and brook trout (Salvelinus fontinalis], collected worldwide within the 1994 to present time frame, were considered. Multivariate techniques (principal component analysis-PCA and mapping approach, showed clear differences in geographic distribution patterns of PBDE levels in trout depending on the region studied: wild trout from European and North American great lakes have the highest PBDE loads. This pattern could be due to high industrial activity at these locations. A correlational approach used to explore intraspecific relationships between PBDE levels and morphometry, showed positive relationships only for brown trout. Further, brown trout showed the highest trout

Autometallographic tracing of mercury in frog liver

International Nuclear Information System (INIS)

Loumbourdis, N.S.; Danscher, G.

2004-01-01

The distribution of mercury in the liver of the frog Rana ridibunda with the autometallographic method was investigated. The mercury specific autometallographic (HgS/Se AMG ) technique is a sensitive histochemical approach for tracing mercury in tissues from mercury-exposed organisms. Mercury accumulates in vivo as mercury sulphur/mercury selenium nanocrystals that can be silver-enhanced. Thus, only a fraction of the Hg can be visualized. Six animals were exposed for one day and another group of six animals for 6 days in 1 ppm mercury (as HgCI 2 ) dissolved in fresh water. A third group of six animals, served as controls, were sacrificed the day of arrival at the laboratory. First, mercury appears in the blood plasma and erythrocytes. Next, mercury moves to hepatocytes and in the apical part of the cells, that facing bile canaliculi. In a next step, mercury appears in the endothelial and Kupffer cells. It seems likely that, the mercury of hepatocytes moves through bile canaliculi to the gut, most probably bound to glutathione and/or other similar ligands. Most probably, the endothelial and Kupffer cells comprise the first line of defense against metal toxicity. - Frogs can be good bioindicators of mercury

Species-specific sensitivity to selenium-induced impairment of cortisol secretion in adrenocortical cells of rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis)

International Nuclear Information System (INIS)

Miller, L.L.; Hontela, A.

2011-01-01

Species differences in physiological and biochemical attributes exist even among closely related species and may underlie species-specific sensitivity to toxicants. Rainbow trout (RT) are more sensitive than brook trout (BT) to the teratogenic effects of selenium (Se), but it is not known whether all tissues exhibit this pattern of vulnerability. In this study, primary cultures of RT and BT adrenocortical cells were exposed to selenite (Na 2 SO 3 ) and selenomethionine (Se-Met) to compare cell viability and ACTH-stimulated cortisol secretion in the two fish species. Cortisol, the primary stress hormone in fish, facilitates maintenance of homeostasis when fish are exposed to stressors, including toxicants. Cell viability was not affected by Se, but selenite impaired cortisol secretion, while Se-Met did not (RT and BT EC 50 > 2000 mg/L). RT cells were more sensitive (EC 50 = 8.7 mg/L) to selenite than BT cells (EC 50 = 90.4 mg/L). To identify the targets where Se disrupts cortisol synthesis, selenite-impaired RT and BT cells were stimulated with ACTH, dbcAMP, OH-cholesterol, and pregnenolone. Selenite acted at different steps in the cortisol biosynthesis pathway in RT and BT cells, confirming a species-specific toxicity mechanism. To test the hypothesis that oxidative stress mediates Se-induced toxicity, selenite-impaired RT cells were exposed to NAC, BSO and antioxidants (DETCA, ATA, Vit A, and Vit E). Inhibition of SOD by DETCA enhanced selenite-induced cortisol impairment, indicating that oxidative stress plays a role in Se toxicity; however, modifying GSH content of the cells did not have an effect. The results of this study, with two closely related salmonids, provided additional evidence for species-specific differences in sensitivity to Se which should be considered when setting thresholds and water quality guidelines. - Research Highlights: → We investigated species-specific sensitivity to Se in trout adrenocortical cells. → Selenite, not Se-Met, disrupts

Lifespan mercury accumulation pattern in Liza aurata : Evidence from two southern European estuaries

Science.gov (United States)

Tavares, S.; Oliveira, H.; Coelho, J. P.; Pereira, M. E.; Duarte, A. C.; Pardal, M. A.

2011-10-01

Mercury accumulation throughout the lifespan of Liza aurata (Risso, 1810) was analysed in four tissues (muscle, gills, liver and brain) in two southern European coastal ecosystems with distinct mercury contamination. Specimens from four to five age classes were captured in two sampling sites in the Ria de Aveiro (Laranjo bay and Mira), a system historically contaminated by industrial mercury, and in one site in the Mondego estuary, assumed as a mercury-free ecosystem. Mercury concentration in all tissues was found to be significantly higher in the Ria de Aveiro (Laranjo bay) compared to the Mondego, in accordance with the environmental contamination (water, sediments and suspended particulate matter). Significant differences inside the Ria de Aveiro (between the Mira and Laranjo bay) were only detected in the liver. This tissue registered the highest levels of mercury (ranging from 0.11 to 4.2 μg g -1 ) in all sampling sites, followed by muscle, brain, and gills. In all sampling sites and tissues was denoted a mercury dilution pattern along the lifecycle (except in liver at the Mondego, the reference area where the concentrations are always very low). An exponential trend was found in the metal age variation patterns in Laranjo (the most contaminated area) and a linear trend in the Mira and the Mondego (the least contaminated areas). Organic mercury concentration in muscle generally accounted for over 95% of total mercury concentration, and followed the same accumulation pattern of total mercury. This fish species is of lesser importance in mercury transfer to adjacent coastal areas and although the consumption of fish from Laranjo may present some risk for the humans, this risk decreases with fish age/size.

Movement of mercury-203 in plants. Final report

International Nuclear Information System (INIS)

Gay, D.D.; Butler, G.P.

1977-10-01

Seeds of Pisum sativum, varieties Little Marvel and Alaska, were planted in soils contaminated with radioactive ionic mercury, methylmercury or phenylmercury compounds. After saturation, stems, leaves, and pods were harvested and analyzed by gamma spectroscopy. Utilizing a least squares three-way analysis of covariance coupled with a Studentized Range Test, significant differences were noted among the levels of the three mercury compounds in the plants, between mercury levels in the two pea varieties and among mercury levels in the different pea tissues examined. Phenylmercury levels differed consistently from levels of ionic mercury and methylmercury suggesting a separate pathway for it in peas

Sensitivity improvements, in the determination of mercury in biological tissues by neutron activation analysis

Energy Technology Data Exchange (ETDEWEB)

Cornett, C R; Samudralwar, D L; Ehmann, W D [Kentucky Univ., Lexington, KY (United States). Dept. of Chemistry; Markesbery, W R [Kentucky Univ., Lexington, KY (United States)

1995-08-01

The possible association of dental amalgam surface exposure, brain mercury (Hg) levels, and pathological markers of Alzheimer`s disease (AD) in the brain is the subject of an on-going study in our laboratory. Two radiochemical neutron activation analysis methods and the use of instrumental neutron activation analysis (INAA) with Compton suppression spectrometry have been evaluated for improving our INAA Hg detection limit (2.8{+-}0.6 ng/g, wet-weight basis) in human tissue. Large numbers of samples dictated the use of a purely instrumental method or rapid, simple radiochemical separations. Human brain tissues and NIST biological standards were analyzed using a precipitation of Hg{sub 2}Cl{sub 2}, a solvent extraction utilizing sodium diethyldithiocarbomate, conventional INAA, and INAA with Compton suppression. The radiochemical precipitation of Hg{sub 2}Cl{sub 2} proved to be the most useful method for use in our study because it provided a simultaneous, quantitative determination of silver (Ag) and a Hg detection limit in brain tissue of 1.6{+-}0.1 ng/g (wet-weight basis). (author). 12 refs., 2 tabs.

A trial of two trouts: Comparing the impacts of rainbow and brown trout on a native galaxiid

Science.gov (United States)

Young, K.A.; Dunham, J.B.; Stephenson, J.F.; Terreau, A.; Thailly, A.F.; Gajardo, G.; de Leaniz, C. G.

2010-01-01

Rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta are the world's two most widespread exotic fishes, dominate the fish communities of most cold-temperate waters in the southern hemisphere and are implicated in the decline and extirpation of native fish species. Here, we provide the first direct comparison of the impacts of rainbow and brown trout on populations of a native fish by quantifying three components of exotic species impact: range, abundance and effect. We surveyed 54 small streams on the island of Chilo?? in Chilean Patagonia and found that the rainbow trout has colonized significantly more streams and has a wider geographic range than brown trout. The two species had similar post-yearling abundances in allopatry and sympatry, and their abundances depended similarly on reach-level variation in the physical habitat. The species appeared to have dramatically different effects on native drift-feeding Aplochiton spp., which were virtually absent from streams invaded by brown trout but shared a broad sympatric range with rainbow trout. Within this range, the species' post-yearling abundances varied independently before and after controlling for variation in the physical habitat. In the north of the island, Aplochiton spp. inhabited streams uninvaded by exotic trouts. Our results provide a context for investigating the mechanisms responsible for apparent differences in rainbow and brown trout invasion biology and can help inform conservation strategies for native fishes in Chilo?? and elsewhere. ?? 2010 The Authors. Journal compilation ?? 2010 The Zoological Society of London.

Depletion of eugenol residues from the skin-on fillet tissue of rainbow trout exposed to 14C-labeled eugenol

Science.gov (United States)

Meinertz, Jeffery R.; Schreier, Theresa M.; Porcher, Scott T.; Smerud, Justin R.; Gaikowski, Mark P.

2014-01-01

The U.S. is lagging in access to an approved immediate-release sedative, i.e. a compound that can be safely and effectively used to sedate fish and has no withdrawal period. AQUI-S® 20E (10% active ingredient, eugenol) is under investigation as an immediate-release sedative for freshwater finfish. Because of its investigational status, data are needed to characterize the depletion, distribution, and identity of AQUI-S® 20E residues in fillet tissue. Rainbow trout (Oncorhynchus mykiss) were exposed to uniformly ring labeled 14C-eugenol at a nominal concentration of 10 mg/L for 60 min in 18 °C water. Fish (n = 6) were sampled immediately after the exposure (0 min) then at 30, 60, 120, and 240 min. Eugenol concentrations and characterization of 14C residues in the fillet tissue were determined by high pressure liquid chromatography and flow-through liquid scintillation counting techniques. Total 14C-residue burdens in fillet tissue were determined by tissue oxidation and static liquid scintillation counting techniques. Maximum eugenol and 14C-eugenol equivalent residue concentrations in the fillet tissue were measured immediately after the exposure (44.5 and 38.8 μg/g, respectively). Eugenol was the primary 14C-residue (> 90% of all 14C-residues) in extracts from fillet tissue taken from fish sampled immediately after the exposure (0 min) and from fish sampled at 30 and 60 min after the exposure. The depletion of 14C-eugenol residues from the fillet tissue was rapid (t1/2 = 26.25 min) after transferring the exposed fish to fresh flowing water.

Microsatellite analyses of the trout of northwest Mexico

Science.gov (United States)

Nielsen, J.L.; Sage, G.K.

2001-01-01

The trout of northwest Mexico represent an undescribed group of fish considered part of the Oncorhynchus mykiss (Pacific trout) complex of species and subspecies. Recent genetic studies have shown these fish to have important genetic diversity and a unique evolutionary history when compared to coastal rainbow trout. Increased levels of allelic diversity have been found in this species at the southern extent of its range. In this study we describe the trout in the Sierra Madre Occidental from the rios Yaqui, Mayo, Casas Grandes and de Bavispe, and their relationship to the more southern distribution of Mexican golden trout (O. chrysogaster) using 11 microsatellite loci. Microsatellite allelic diversity in Mexican trout was high with a mean of 6.6 alleles/locus, average heterozygosity = 0.35, and a mean Fst = 0.43 for all loci combined. Microsatellite data were congruent with previously published mtDNA results showing unique panmictic population structure in the Rio Yaqui trout that differs from Pacific coastal trout and Mexican golden trout. These data also add support for the theory of headwaters transfer of trout across the Continental Divide from tributaries of the Rio de Bavispe into the Rio Casas Grandes. Rio Mayo trout share a close genetic relationship to trout in Rio Yaqui, but sample sizes from the Rio Mayo prevent significant comparisons in this study. Microsatellite analyses show significant allelic frequency differences between Rio Yaqui trout and O. chrysogaster in Sinaloa and Durango Mexico, adding further support for a unique evolutionary status for this group of northwestern Mexican trout.

Mercury distribution in the main compartments of the eutrophic Lake Candia (Northern Italy

Directory of Open Access Journals (Sweden)

Gian Maria BEONE

2009-08-01

Full Text Available Total mercury (T-Hg and organic mercury (mainly methylmercury, MeHg concentrations in the most important compartments (water, sediment, macrophytes, zooplankton, mussels and fish of the shallow and eutrophic Lake Candia (Turin, Northern Italy were measured. The decreasing sequence of the T-Hg concentrations is as follows: cat-fish (143 μg kg-1 d.w., zooplankton (77 μg kg-1 d.w., Unio pictorum mancus (37.9 μg kg-1 d.w., macrophytes (28.9 μg kg-1 d.w.. The content of mercury in mussel tissues increased with the size of the animal, but the relationship between Hg concentration and tissue weight was negative, indicating that the rate of mercury accumulation was lower than the tissue growth rate. The amount of mercury accumulated in the mussels living in the lake sediments was estimated to be 0.54 μg m-2. The importance of mercury biomagnification is also discussed.

Uptake, distribution, and incorporation of 59Fe in tissue and blood of rainbow trout (Salmo gairdneri)

International Nuclear Information System (INIS)

Walker, R.L.

1975-01-01

A study was designed to evaluate the storage iron facilities in various tissues and to trace the distribution of radioiron in tissues and blood following an intraperitoneal (i.p.) injection of 59 Fe. Iron deficiency anemia was induced in an experimental group of rainbow trout in order to measure its effect on red blood cell production and mobilization of storage iron. Most of the 59 Fe was absorbed from the peritoneal cavity within 24 hrs. after the i.p. injection. Equilibrium between the plasma 59 Fe pool and that of the tissue was established by day 8. Experimental fish RBC 59 Fe content increased to 70 to 80 percent of the initial injected dose by day 16 compared to 50 percent in the controls. This was attributed to the difference in reticulocyte count which was 10 to 12 percent for the bled and 2 to 3 percent for control fish. The rate that iron is incorporated into hemoglobin by immature red cells is much slower (about half) than the rate of RBC 59 Fe uptake, thus, iron is temporarily stored in the cytoplasm. The iron for hemoglobin formation was obtained from liver iron stores which dropped from 12 percent to less than 1 percent of the initial injected dose by day 16. Total iron concentration in liver decreased from 200 to less than 100 μg Fe/g. The decrease in liver iron may have stimulated iron absorption by the intestine and pyloric caeca. There is evidence for a feedback mechanism mediated by transferrin

COMPARISON OF THE QUALITY OF RNA ISOLATED FROM THE RAINBOW TROUT (Oncorhynchus mykiss TISSUE IN FOUR DIFFERENT WAYS

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Irena Vardić

2004-03-01

Full Text Available Rapid and accurate diagnostic procedures for identification of reared fish diseases are important in order to reduce serious losses in relation of diseases outbrakes. Therefore, molecular biology methods are required for such types of investigations. First level in these experiments are DNA or RNA isolation. Tissue preparation for isolation of RNA, which is used in further RT-PCR (reverse transcription-polymerise chain reaction analysis is the key step on which is the whole process of analysis dependent. Our goal was to compare quality and integrity of RNA isolated from the rainbow trout tissue, which was prepared in four different ways: fresh tissue, frozen tissue, in formalin-fixed, paraffin embedded tissue as well as in methacarn-fixed, paraffin embedded tissue. Isolated RNA was analyzed in gel electrophoresis on non-denaturated, 1% agarose gel. Quality and integrity of RNA was proved by RT-PCR reaction with primers for ß-actin gene. Additional, prepared tissue was tested on presence of two fish viruses: viral haemorrhagic septicaemia (VHS virus and infectious haematopoietic necrosis (IHN virus in RT-PCR reaction with primers specific for these viruses. RNA isolated from fresh and frozen tissue was of high quality, integrity and quantity. RNA isolated from in methacarn-fixed, paraffin embedded tissue was quite disintegrated, but in RT-PCR with primers for ß-actin gave expected products. These products were absent after RT-PCR reaction with in formallin-fixed, paraffin-embedded tissue. That agrees with the facts from the literature about very agressive affect of formalin as a fixative on RNA in tissue. Inspected fish were not infected with VHS and IHN viruses and that was in agreement with results of clinical examination and pathological analysis. According to our knowledge, this is the first successful RNA isolation from in methacarn-fixed, paraffin embedded fish tissue. Isolated RNA can be used for further analysis in RT-PCR reaction. This

Environmental monitoring of the La Grande complex (2003-2004) : evolution of mercury levels in the flesh of fish

International Nuclear Information System (INIS)

Therrien, J.; Schetagne, R.

2005-11-01

The results of surveys conducted to assess the duration of temporary mercury levels in piscivorous species in the La Grande Complex were presented. A 2003 survey conducted in the easter sector and a 2004 survey conducted in the western sector of the complex showed that for non-piscivorous fishes of standardized length, a return to mean natural mercury levels will be achieved between 10 and 20 years after impounding. For piscivorous fishes, the evolution pattern of the mean mercury levels suggested that a return to background levels will occur after 20 to 30 years. Mercury levels for northern pike in the Robert-Bourassa Reservoir are expected to return to normal levels after 30 to 35 years. The surveys indicated that mean mercury levels in non-piscivorous fishes were often higher immediately below the La Grande generating stations. Similar observations were made for northern pike and lake trout downstream of the generating stations in the eastern sector of the complex. Mean mercury levels were significantly higher for fishes in the complex than fishes in the natural lakes of the region. Results of the surveys suggested that additional consumption restrictions for piscivorous fishes in the reservoirs are needed. Consumption guidelines for varieties of non-piscivorous and piscivorous fishes from the complex were included

Mercury Concentration in the Tissue of Terrestrial Arthropods from the Central California Coast

Science.gov (United States)

Ortiz, C.; Weiss-Penzias, P. S.; Flegal, A. R.

2012-12-01

The primary goal of this project was to obtain a baseline understanding and investigate the concentration of mercury (Hg) in the tissue of arthropods in coastal California. This region receives significant input of fog which may contain enhanced levels of Hg. Currently there is a lack of data on Hg concentration in the tissue of arthropods (Insecta, Malacostraca, and Arachnida). The sample collection sites were Elkhorn Slough Estuarine Reserve in Moss Landing, and the University of California Santa Cruz (UCSC) campus. Samples collected between February and March, 2012 had total Hg (HgT) concentrations in dry weight that ranged from 27 - 39 ng/g in the Jerusalem cricket (Orthoptera Stenopelmatidae); 80 - 110 ng/g in the camel cricket (Orthoptera Rhaphidophoridae); 21 - 219 ng/g in the ground beetle (Coleoptera Carabidae); 100 - 228 ng/g in the pill bug (Isopoda Armadillidiidae); and 285 - 423 ng/g in the wolf spider (Araneae Lycosidae). Monomethyl mercury (MMHg) concentrations in dry weight were determine to be 4.3 -28.2 ng/g for the ground beetle; 45.5 - 87.8 ng/g for the pill bug, and 252.3 - 293.7 ng/g for the wolf spider. Samples collected in July, 2012 had HgT concentrations in dry weight that ranged from 110 - 168 ng/g in the camel cricket; 337 - 562 ng/g in the ground beetle; 25 - 227 ng/g in the pill bug; and 228 - 501 ng/g in the wolf spider. The preliminary data revealed an 18% increase in the concentration of HgT for wolf spiders, and a 146% increase for ground beetles in the summer when compared to those concentrations measured in the spring. It is hypothesized that coastal fog may be a contributor to this increase of Hg concentration in coastal California arthropods.

Spatial variation of mercury bioaccumulation in bats of Canada linked to atmospheric mercury deposition.

Science.gov (United States)

Chételat, John; Hickey, M Brian C; Poulain, Alexandre J; Dastoor, Ashu; Ryjkov, Andrei; McAlpine, Donald; Vanderwolf, Karen; Jung, Thomas S; Hale, Lesley; Cooke, Emma L L; Hobson, Dave; Jonasson, Kristin; Kaupas, Laura; McCarthy, Sara; McClelland, Christine; Morningstar, Derek; Norquay, Kaleigh J O; Novy, Richard; Player, Delanie; Redford, Tony; Simard, Anouk; Stamler, Samantha; Webber, Quinn M R; Yumvihoze, Emmanuel; Zanuttig, Michelle

2018-06-01

Wildlife are exposed to neurotoxic mercury at locations distant from anthropogenic emission sources because of long-range atmospheric transport of this metal. In this study, mercury bioaccumulation in insectivorous bat species (Mammalia: Chiroptera) was investigated on a broad geographic scale in Canada. Fur was analyzed (n=1178) for total mercury from 43 locations spanning 20° latitude and 77° longitude. Total mercury and methylmercury concentrations in fur were positively correlated with concentrations in internal tissues (brain, liver, kidney) for a small subset (n=21) of little brown bats (Myotis lucifugus) and big brown bats (Eptesicus fuscus), validating the use of fur to indicate internal mercury exposure. Brain methylmercury concentrations were approximately 10% of total mercury concentrations in fur. Three bat species were mainly collected (little brown bats, big brown bats, and northern long-eared bats [M. septentrionalis]), with little brown bats having lower total mercury concentrations in their fur than the other two species at sites where both species were sampled. On average, juvenile bats had lower total mercury concentrations than adults but no differences were found between males and females of a species. Combining our dataset with previously published data for eastern Canada, median total mercury concentrations in fur of little brown bats ranged from 0.88-12.78μg/g among 11 provinces and territories. Highest concentrations were found in eastern Canada where bats are most endangered from introduced disease. Model estimates of atmospheric mercury deposition indicated that eastern Canada was exposed to greater mercury deposition than central and western sites. Further, mean total mercury concentrations in fur of adult little brown bats were positively correlated with site-specific estimates of atmospheric mercury deposition. This study provides the largest geographic coverage of mercury measurements in bats to date and indicates that atmospheric

Central ventilatory and cardiovascular actions of trout gastrin-releasing peptide (GRP in the unanesthetized trout

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Jean-Claude Le Mével

2013-07-01

Gastrin-releasing peptide (GRP, a neuropeptide initially isolated from porcine stomach, shares sequence similarity with bombesin. GRP and its receptors are present in the brains and peripheral tissues of several species of teleost fish, but little is known about the ventilatory and cardiovascular effects of this peptide in these vertebrates. The goal of this study was to compare the central and peripheral actions of picomolar doses of trout GRP on ventilatory and cardiovascular variables in the unanesthetized rainbow trout. Compared to vehicle, intracerebroventricular (ICV injection of GRP (1–50 pmol significantly elevated the ventilation rate (ƒV and the ventilation amplitude (VAMP, and consequently the total ventilation (VTOT. The maximum hyperventilatory effect of GRP (VTOT: +225%, observed at a dose of 50 pmol, was mostly due to its stimulatory action on VAMP (+170% rather than ƒV (+20%. In addition, ICV GRP (50 pmol produced a significant increase in mean dorsal aortic blood pressure (PDA (+35% and in heart rate (ƒH (+25%. Intra-arterial injections of GRP (5–100 pmol were without sustained effect on the ventilatory variables but produced sporadic and transient increases in ventilatory movement at doses of 50 and 100 pmol. At these doses, GRP elevated PDA by +20% but only the 50 pmol dose significantly increased HR (+15%. In conclusion, our study suggests that endogenous GRP within the brain of the trout may act as a potent neurotransmitter and/or neuromodulator in the regulation of cardio-ventilatory functions. In the periphery, endogenous GRP may act as locally-acting and/or circulating neurohormone with an involvement in vasoregulatory mechanisms.

Oral transmission as a route of infection for viral haemorrhagic septicaemia virus in rainbow trout, Oncorhynchus mykiss (Walbaum)

DEFF Research Database (Denmark)

Schönherz, Anna Amanda; Hansen, M. H. H.; Jørgensen, H. B. H.

2012-01-01

replication in stomach and kidney tissue was detected through bioluminescence activity of luciferase and qRT‐PCR. Replication was detected in both tissues, irrespective of transmission route. Replication patterns, however, differed among transmission routes. In trout infected through oral transmission...

Larger eggs in resident brown trout living in sympatry with anadromous brown trout

DEFF Research Database (Denmark)

Olofsson, H.; Mosegaard, Henrik

1999-01-01

Freshwater resident brown trout (Salmo trutta L.) in the stream Jorlandaan (southwestern Sweden) had larger eggs (range of actual mean egg wet weights, 65.9-108.5 mg) than both sympatric migratory trout (76.8-84.2 mg) and trout from five other Swedish streams with allopatric resident (23.7-80.1 mg......) or migratory populations (44.5-121.9 mg), after accounting for differences in body size. In Jorlandaan, some resident females even had a larger absolute mean egg weight than any of the migratory females found in the stream Resident trout had low absolute fecundity, and our data suggest that resident females...... in Jorlandan produce large eggs at the expense of their fecundity The extremely large relative egg size in resident Jorlandaan females suggests that the production of large offspring enhances fitness, possibly through increased fry survival....

Seasonal Variations in Relative Weight of Lake Trout (Salvelinus namaycush), Kokanee Salmon (Oncorhynchus nerka), Rainbow Trout (Onocorhynchus mykiss), and Brown Trout (Salmo trutta) in Blue Mesa Reservoir, Colorado

OpenAIRE

Midas, Madeline; Williams, Asia; Cooper, Cindy; Courtney, Michael

2013-01-01

Blue Mesa Reservoir is the largest body of water in Colorado and is located on the western slope of the Rocky Mountains at an elevation of 7520 feet. Blue Mesa Reservoir contains recreationally important populations of lake trout (Salvelinus namaycush), kokanee salmon (Oncorhynchus nerka), rainbow trout (Onocorhynchus mykiss), and brown trout (Salmo trutta). A management challenge in recent years has been the overpopulation of lake trout, which has led to a steep decline in abundance of kokan...

Mercury accumulation in native mammals of the Southeast

Energy Technology Data Exchange (ETDEWEB)

Cumbie, P.M.; Jenkins, J.H.

1974-01-01

Mercury levels in tissues of mammals collected in Georgia, Florida, and South Carolina were compared using hair mercury concentration as an index of total mercury content. Bobcats (Lynx rufus), raccoons (Procyon lotor), opossum (Didelphis marsupialis) and gray fox (Urocyon cinereoargenteus) from the Lower Coastal Plain of Georgia had higher mercury levels than specimens from the Upper Coastal Plain or Piedmont. The highest individual mercury levels in raccoons and bobcats occurred in specimens from the Georgia Lower Coastal Plain flatwoods. Skeletal muscle and liver of individual raccoons and bobcats taken in the coastal flatwoods exceeded the 0.5 ppm limit for mercury in human foodstuffs. No pattern of mercury accumulation was detected in white-tailed deer (Odocoileus virginianus). Hair analysis revealed elevated mercury levels in mammals from a region exposed to mercury pollution. Mercury levels in wildlife exhibit a pattern similar to that of certain fallout radioisotopes such as /sub 137/Cs. These observations indicate that significant biomagnification of mercury may occur in native mammals in certain southeastern habitats. 28 references, 6 tables.

Do native brown trout and non-native brook trout interact reproductively?

Science.gov (United States)

Cucherousset, J.; Aymes, J. C.; Poulet, N.; Santoul, F.; Céréghino, R.

2008-07-01

Reproductive interactions between native and non-native species of fish have received little attention compared to other types of interactions such as predation or competition for food and habitat. We studied the reproductive interactions between non-native brook trout ( Salvelinus fontinalis) and native brown trout ( Salmo trutta) in a Pyrenees Mountain stream (SW France). We found evidence of significant interspecific interactions owing to consistent spatial and temporal overlap in redd localizations and spawning periods. We observed mixed spawning groups composed of the two species, interspecific subordinate males, and presence of natural hybrids (tiger trout). These reproductive interactions could be detrimental to the reproduction success of both species. Our study shows that non-native species might have detrimental effects on native species via subtle hybridization behavior.

Malheur River Basin cooperative bull trout/redband trout research project, annual report FY 1999; ANNUAL

International Nuclear Information System (INIS)

Schwabe, Lawrence; Tiley, Mark

2000-01-01

The purpose of this study is to document the seasonal distribution of adult/sub-adult bull trout (Salvelinus confluentus) in the Malheur River basin. Due to the decline of bull trout in the Columbia Basin, the United States Fish and Wildlife Service listed bull trout as a threatened species in June 1998. Past land management activities; construction of dams; and fish eradication projects in the North Fork and Middle Fork Malheur River by poisoning have worked in concert to cumulatively impact native species in the Malheur Basin (Bowers et. al. 1993). Survival of the remaining bull trout populations is severely threatened (Buchanan 1997). 1999 Research Objects are: (1) Document the migratory patterns of adult/sub-adult bull trout in the North Fork Malheur River; (2) Determine the seasonal bull trout use of Beulah Reservoir and bull trout entrainment; and (3) Timing and location of bull trout spawning in the North Fork Malheur River basin. The study area includes the Malheur basin from the mouth of the Malheur River located near Ontario, Oregon to the headwaters of the North Fork Malheur River (Map 1). All fish collected and most of the telemetry effort was done on the North Fork Malheur River subbasin (Map 2). Fish collection was conducted on the North Fork Malheur River at the tailwaters of Beulah Reservoir (RK 29), Beulah Reservoir (RK 29-RK 33), and in the North Fork Malheur River at Crane Crossing (RK 69) to the headwaters of the North Fork Malheur. Radio telemetry was done from the mouth of the Malheur River in Ontario, Oregon to the headwaters of the North Fork Malheur. This report will reflect all migration data collected from 3/1/99 to 12/31/99

Distribution and excretion of methyl and phenyl mercury salts

Energy Technology Data Exchange (ETDEWEB)

Gage, J C

1964-01-01

The distribution, metabolism, and excretion of phenyl mercury acetate (P.M.A.) and of methyl mercury dicyanidiamide (M.M.D.) has been studied in the rat during the repeated subcutaneous administration of small doses over a period of six weeks, and for several weeks after a single dose. The results indicate that P.M.A. is absorbed unchanged into the circulation from which it is mainly removed by the liver and kidneys where it is metabolized and excreted in the feces and urine mostly as inorganic mercury. During repeated dosage the rats reached a steady state by the end of the second week when excretion approximately balanced intake. No measurable amount of mercury was found in the central nervous system. After repeated dosage with M.M.D. there is no clear indication of a steady state being reached after six weeks. There is an accumulation of organic mercury in all tissues, particularly in the red cells, and a progressive increase in the brain concentration. M.M.D. is more slowly released from the tissues than P.M.A. and the breakdown to inorganic mercury is low. The control of human exposure to alkyl and aryl mercury salts is considered in the light of these experimental observations. The recommendation that the concentration of alkyl mercury salts in the atmosphere should not exceed 0-01 mg/m/sup 3/ seems justifiable, but there appears to be no reason to establish the figure for aryl mercury salts below the 0-1 mg/m/sup 3/ recommended for inorganic mercury vapor. 13 references, 4 tables.

Mercury concentrations in multiple tissues of Kittlitz's murrelets (Brachyramphus brevirostris)

Science.gov (United States)

Kenney, Leah A.; Kaler, Robb S.; Kissling, Michelle L.; Bond, Alexander L.; Eagles-Smith, Collin A.

2018-01-01

Mercury (Hg) is a non-essential, toxic metal that is distributed worldwide. Mercury biomagnifies in food webs and can threaten the health of top predators such as seabirds. The Kittlitz's murrelet (Brachyramphus brevirostris) is a seabird endemic to Alaska and the Russian Far East and is a species of conservation concern in the region. We determined Hg concentrations in eggshells, guano, blood, and feathers of Kittlitz's murrelets sampled from four locations in Alaska. Mercury concentrations in eggshells, guano, and blood were low compared to other seabird species. Mean Hg concentrations of breast feathers from Adak Island and Glacier Bay were significantly greater than those from Agattu Island or Icy Bay. Two Kittlitz's murrelets at Glacier Bay and one Kittlitz's murrelet at Adak Island had Hg concentrations above those associated with impaired reproduction in other bird species, and may merit further investigation as a potential threat to individuals and populations.

Selenium-induced autometallographic demonstration of endogenous zinc in organs of the rainbow trout, Salmo gairdneri

DEFF Research Database (Denmark)

Baatrup, E

1989-01-01

, the intestine, and the gills, whereas, no such grains were found in preparations from fish having received 1 ppm Se. The use of selenium for the histochemical demonstration of endogenous zinc versus exogenous metals is discussed. Also, consideration is given to the question of which part of the total tissue......Autometallographic (AMG) silver enhancement of endogenous zinc was studied in seven organs of the rainbow trout Salmo gairdneri. Groups of trout were injected intraperitoneally with sodium selenite in doses ranging from 0.08 to 25 ppm, administered 1 h before being killed. The concentration...

Bony fish myelin: evidence for common major structural glycoproteins in central and peripheral myelin of trout.

Science.gov (United States)

Jeserich, G; Waehneldt, T V

1986-02-01

Peripheral nervous system (PNS) myelin from the rainbow trout (Salmo gairdneri) banded at a density of 0.38 M sucrose. The main myelin proteins consisted of (1) two basic proteins, BPa and BPb (11,500 and 13,000 MW, similar to those of trout central nervous system (CNS) myelin proteins BP1 and BP2), and (2) two glycosylated components, IPb (24,400 MW) and IPc (26,200 MW). IPc comigrated with trout CNS myelin protein IP2 in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, whereas trout CNS myelin protein IP1 had a lower molecular weight (23,000). Following two-dimensional separation, however, both IPb and IPc from PNS showed two components; the more acidic component of IPc comigrated with IP2 from CNS. PNS tissue autolysis led to the formation of IPa (20,000 MW), consisting of two components in isoelectric focusing of which again the more acidic one comigrated with the CNS autolysis product IP0. Limited enzymatic digestion of isolated IP proteins from PNS and CNS led to closely similar degradation patterns, being most pronounced in the case of IP2 and IPc. Immunoblotting revealed that all IP components from trout PNS and CNS myelins reacted with antibodies to trout IP1 (CNS) and bovine P0 protein (PNS) whereas antibodies to rat PLP (CNS) were entirely unreactive. All BP components from trout PNS and CNS myelins bound to antibodies against human myelin basic protein. On the basis of these studies trout PNS and CNS myelins contain at least one common IP glycoprotein, whereas other members of the IP myelin protein family appear closely related. In the CNS myelin of trout the IP components appear to replace PLP.(ABSTRACT TRUNCATED AT 250 WORDS)

Ecological and physiological parameters of mercury and cesium-137 accumulation in the raccoon

International Nuclear Information System (INIS)

Davis, A.H.

1981-01-01

Raccoons from 4 regions in the southeastern Coastal Plain were evaluated for mercury content. Mercury content of hair when used as an indicator of total body mercury content was significantly different among 3 of the 4 areas: Okefenokee Swamp, Eglin Air Force Base, and Sapelo Island on the Georgia Coast. Raccoons from Echols County Georgia were not significantly different from those of the Okefenokee. Mercury in the liver and kidney was significantly different between Okefenokee and Sapelo. There was a strong correlation between the age of the raccoon and the mercury in hair, with older animals having higher concentrations. This relationship was also valid for most other tissues. There was evidence that mercury content in some tissues was correlated with the season and the body condition of the raccoon. Mercury was not transferred through the placenta to the fetal raccoons. There was a strong relationship of mercury content to raccoon behavioral characteristics. Raccoon body weight was slightly different between the areas studied. Cesium-137 values in raccoons were significantly different between the Okefenokee and Sapelo Island. Cesium-137 content was correlated with raccoon age, body weight, and mercury content. Generally non-detectable levels of chlorinated hydrocarbons and PCB were found in Okefenokee raccoons. Mercury concentrations in crayfish were generally low but probably of importance in the raccoon food chain. The biological half life of mercury in brain, gonad, pancreas, spleen, heart, and lung was approximately 52 days. The half-life of mercury in muscle was 35 days. Mercury content of hair, liver, and kidney decreased at very slow rates, with biological half lives of 229, 108, and 138 days. This was probably due to the role of these tissues in clearance of mercury from the body, and to the molting pattern of raccoon hair

Effects of hybridization between nonnative Rainbow Trout and native Westslope Cutthroat Trout on fitness-related traits

Science.gov (United States)

Drinan, Daniel P.; Webb, Molly A. H.; Naish, Kerry A.; Kalinowski, Steven T.; Boyer, Matthew C.; Steed, Amber C.; Shepard, Bradley B.; Muhlfeld, Clint C.

2015-01-01

Hybridization between introduced and native fauna is a risk to native species and may threaten the long-term persistence of numerous taxa. Rainbow Trout Oncorhynchus mykiss has been one of the most widely introduced species around the globe and often hybridizes with native Cutthroat Trout O. clarkii in the Rocky Mountains. Previous work has shown that hybridization negatively affects reproductive success, but identification of the traits contributing to that reduction has been elusive. In this study, we used a combination of field and laboratory techniques to assess how hybridization with Rainbow Trout affects seven traits during several stages of Westslope Cutthroat Trout development: embryonic survival, ova size, ova energy concentration, sperm motility, juvenile weight, juvenile survival, and burst swimming endurance. Rainbow Trout admixture was correlated with an increase in embryonic survival and ova energy concentration but with a decrease in juvenile weight and burst swimming endurance. These correlations differed from previously observed patterns of reproductive success and likely do not explain the declines in reproductive success associated with admixture. Future investigation of additional, unstudied traits and the use of different environments may shed light on the traits responsible for reproductive success in admixed Cutthroat Trout.

Prediction of mercury bioavailability to common carp (Cyprinus carpio L.) using the diffusive gradient in thin film technique.

Science.gov (United States)

Pelcová, Pavlína; Vičarová, Petra; Ridošková, Andrea; Dočekalová, Hana; Kopp, Radovan; Mareš, Jan; Poštulková, Eva

2017-11-01

The mercury bioaccumulation by common carp (Cyprinus carpio L.) tissues (gills, skin, eyes, scales, muscle, brain, kidneys, liver, and spleen) and the capability of the diffusive gradient in thin film (DGT) technique to predict bioavailability of mercury for individual carp's tissues were evaluated. Carp and DGT units were exposed to increasing concentrations of mercury (Hg 2+ : 0 μg L -1 , 0.5 μg L -1 , 1.5 μg L -1 and 3.0 μg L -1 ) in fish tanks for 14 days. In the uncontaminated fish group, the highest mercury concentration was determined in the muscle tissues and, in fish groups exposed to mercury, the highest mercury concentration was determined in the detoxification (kidneys) and input (gills) organs. A strong and positive correlation between the rate of mercury uptake by the DGT technique and the rate of mercury accumulation by fish tissues (gills, skin, scales, and eyes) was observed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Factors influencing the distribution of native bull trout and westslope cutthroat trout in western Glacier National Park, Montana

Science.gov (United States)

D'Angelo, Vincent S.; Muhlfeld, Clint C.

2013-01-01

The widespread declines of native bull trout (Salvelinus confluentus) and westslope cutthroat trout (Oncorhynchus clarkii lewisi) populations prompted researchers to investigate factors influencing their distribution and status in western Glacier National Park, Montana. We evaluated the association of a suite of abiotic factors (stream width, elevation, gradient, large woody debris density, pool density, August mean stream temperature, reach surface area) with the occurrence (presence or absence) of bull trout and westslope cutthroat trout in 79 stream reaches in five sub-drainages containing glacial lakes. We modeled the occurrence of each species using logistic regression and evaluated competing models using an information theoretic approach. Westslope cutthroat trout were widely distributed (47 of 79 reaches), and there appeared to be no restrictions on their distribution other than physical barriers. Westslope cutthroat trout were most commonly found in relatively warm reaches downstream of lakes and in headwater reaches with large amounts of large woody debris and abundant pools. By contrast, bull trout were infrequently detected (10 of 79 reaches), with 7 of the 10 (70%) detections in sub-drainages that have not been compromised by non-native lake trout (S. namaycush). Bull trout were most often found in cold, low-gradient reaches upstream of glacial lakes. Our results indicate that complex stream habitats in sub-drainages free of non-native species are important to the persistence of native salmonids in western Glacier National Park. Results from this study may help managers monitor and protect important habitats and populations, inform conservation and recovery programs, and guide non-native species suppression efforts in Glacier National Park and elsewhere.

Acute exposure of mercury chloride stimulates the tissue regeneration program and reactive oxygen species production in the Drosophila midgut.

Science.gov (United States)

Chen, Zhi; Wu, Xiaochun; Luo, Hongjie; Zhao, Lingling; Ji, Xin; Qiao, Xianfeng; Jin, Yaping; Liu, Wei

2016-01-01

We used Drosophila as an animal model to study the digestive tract in response to the exposure of inorganic mercury (HgCl2). We found that after oral administration, mercury was mainly sequestered within the midgut. This resulted in increased cell death, which in turn stimulated the tissue regeneration program, including accelerated proliferation and differentiation of the intestinal stem cells (ISCs). We further demonstrated that these injuries correlate closely with the excessive production of the reactive oxygen species (ROS), as vitamin E, an antioxidant reagent, efficiently suppressed the HgCl2-induced phenotypes of midgut and improved the viability. We propose that the Drosophila midgut could serve as a suitable model to study the treatment of acute hydrargyrism on the digestive systems. Copyright © 2015 Elsevier B.V. All rights reserved.

Lipopolysaccharide O-antigen prevents phagocytosis of Vibrio anguillarum by rainbow trout (Oncorhynchus mykiss skin epithelial cells.

Directory of Open Access Journals (Sweden)

Kristoffer Lindell

Full Text Available Colonization of host tissues is a first step taken by many pathogens during the initial stages of infection. Despite the impact of bacterial disease on wild and farmed fish, only a few direct studies have characterized bacterial factors required for colonization of fish tissues. In this study, using live-cell and confocal microscopy, rainbow trout skin epithelial cells, the main structural component of the skin epidermis, were demonstrated to phagocytize bacteria. Mutant analyses showed that the fish pathogen Vibrio anguillarum required the lipopolysaccharide O-antigen to evade phagocytosis and that O-antigen transport required the putative wzm-wzt-wbhA operon, which encodes two ABC polysaccharide transporter proteins and a methyltransferase. Pretreatment of the epithelial cells with mannose prevented phagocytosis of V. anguillarum suggesting that a mannose receptor is involved in the uptake process. In addition, the O-antigen transport mutants could not colonize the skin but they did colonize the intestines of rainbow trout. The O-antigen polysaccharides were also shown to aid resistance to the antimicrobial factors, lysozyme and polymyxin B. In summary, rainbow trout skin epithelial cells play a role in the fish innate immunity by clearing bacteria from the skin epidermis. In defense, V. anguillarum utilizes O-antigen polysaccharides to evade phagocytosis by the epithelial cells allowing it to colonize rapidly fish skin tissues.

Lipopolysaccharide O-Antigen Prevents Phagocytosis of Vibrio anguillarum by Rainbow Trout (Oncorhynchus mykiss) Skin Epithelial Cells

Science.gov (United States)

Lindell, Kristoffer; Fahlgren, Anna; Hjerde, Erik; Willassen, Nils-Peder; Fällman, Maria; Milton, Debra L.

2012-01-01

Colonization of host tissues is a first step taken by many pathogens during the initial stages of infection. Despite the impact of bacterial disease on wild and farmed fish, only a few direct studies have characterized bacterial factors required for colonization of fish tissues. In this study, using live-cell and confocal microscopy, rainbow trout skin epithelial cells, the main structural component of the skin epidermis, were demonstrated to phagocytize bacteria. Mutant analyses showed that the fish pathogen Vibrio anguillarum required the lipopolysaccharide O-antigen to evade phagocytosis and that O-antigen transport required the putative wzm-wzt-wbhA operon, which encodes two ABC polysaccharide transporter proteins and a methyltransferase. Pretreatment of the epithelial cells with mannose prevented phagocytosis of V. anguillarum suggesting that a mannose receptor is involved in the uptake process. In addition, the O-antigen transport mutants could not colonize the skin but they did colonize the intestines of rainbow trout. The O-antigen polysaccharides were also shown to aid resistance to the antimicrobial factors, lysozyme and polymyxin B. In summary, rainbow trout skin epithelial cells play a role in the fish innate immunity by clearing bacteria from the skin epidermis. In defense, V. anguillarum utilizes O-antigen polysaccharides to evade phagocytosis by the epithelial cells allowing it to colonize rapidly fish skin tissues. PMID:22662189

Mercury in mussels of Bellingham Bay, Washington, (USA)

Energy Technology Data Exchange (ETDEWEB)

Roesijadi, G.; Drum, A.S.; Bridge, J.R.

1978-11-01

Laboratory experiments demonstrated the existence of metallothionein-like, low molecular weight, mercury-binding proteins in the marine mussel Mytilus edulis. Relatively large quantities of mercury were associated with such proteins in gills and digestive gland, the organs of interest in the present study. /sup 14/C-incorporation indicated induction of the protein in gills, but not in digestive gland. Mercury in digestive gland may have bound to existing metal-binding proteins. Short-term incorporation of mercury occurred primarily in gills. The induction of mercury-binding proteins in gills may have facilitated detoxification of mercury at the site of uptake. Mercury in mussels of Bellingham Bay were shown to have decreased from 1970 to 1978, the collection date for the present study. Mercury levels were low but approximately three times higher than those from uncontaminated areas. Mercury associated with the mercury-binding protein of gills and digestive glands of Bellingham Bay mussels were low and reflected the concentrations measured in the whole tissues. However, the highest concentration of mercury was associated with the low molecular pool components, the identity of which is not presently known.

Rethinking mercury: the role of selenium in the pathophysiology of mercury toxicity.

Science.gov (United States)

Spiller, Henry A

2018-05-01

There is increasing evidence that the pathophysiological target of mercury is in fact selenium, rather than the covalent binding of mercury to sulfur in the body's ubiquitous sulfhydryl groups. The role of selenium in mercury poisoning is multifaceted, bidirectional, and central to understanding the target organ toxicity of mercury. An initial search was performed using Medline/PubMed, Toxline, Google Scholar, and Google for published work on mercury and selenium. These searches yielded 2018 citations. Publications that did not evaluate selenium status or evaluated environmental status (e.g., lake or ocean sediment) were excluded, leaving approximately 500 citations. This initial selection was scrutinized carefully and 117 of the most relevant and representative references were selected for use in this review. Binding of mercury to thiol/sulfhydryl groups: Mercury has a lower affinity for thiol groups and higher affinity for selenium containing groups by several orders of magnitude, allowing for binding in a multifaceted way. The established binding of mercury to thiol moieties appears to primarily involve the transport across membranes, tissue distribution, and enhanced excretion, but does not explain the oxidative stress, calcium dyshomeostasis, or specific organ injury seen with mercury. Effects of mercury on selenium and the role this plays in the pathophysiology of mercury toxicity: Mercury impairs control of intracellular redox homeostasis with subsequent increased intracellular oxidative stress. Recent work has provided convincing evidence that the primary cellular targets are the selenoproteins of the thioredoxin system (thioredoxin reductase 1 and thioredoxin reductase 2) and the glutathione-glutaredoxin system (glutathione peroxidase). Mercury binds to the selenium site on these proteins and permanently inhibits their function, disrupting the intracellular redox environment. A number of other important possible target selenoproteins have been identified

Relationship between catalase activity and uptake of elemental mercury by rat brain

International Nuclear Information System (INIS)

Eide, I.; Syversen, T.L.M.

1983-01-01

Uptake of mercury by brain after intravenous injection of elemental mercury was investigated in the rat. Catalase activity was inhibited by aminotriazole either by intraperitoneal affecting catalase in most tissues of the animal or by intraventricular injections affecting catalase in the brain selectively. Uptake of elemental mercury by rat brain was not influenced by intraperitoneal administration of aminotriazole resulting in 50% inhibition of brain catalase. However, when the inhibitor was injected intraventricularly in concentrations to give a 50% inhibition of brain catalase, it was shown that the mercury uptake by brain was significantly decreased. In the latter case when only brain catalase was inhibited and the supply of elemtal mercury to brain was maintained, mercury uptake by brain was proportional to the activity of catalase in brain tissue and to the injected amount of elemental mercury. Contrary to the intraventricular injection of aminotriazole, in animals recieving aminotriazole intraperitoneally prior to elemental mercury injection, we suggest that the lower activity of brain catalse is compensated by an increased supply of elemtal mercury caused by the generally lower oxidation rate in the animal. This view is supported by the finding that mercury uptake by liver increased due to aminotriazole intraperitoneally although activity of catalase was depressed. (author)

Mercury in the Umbilical Cord: Implications for Risk Assessment for Minamata Disease

DEFF Research Database (Denmark)

Dalgård, Christine; Grandjean, Philippe; Jørgensen, Poul Jørgen

1994-01-01

Umbilical cord tissue was obtained from 50 births in the Faroe Islands, where high mercury intake is due to ingestion of pilot whale meat. The mercury concentration correlated significantly with the frequency of maternal whale meat dinners during pregnancy and with mercury concentrations in umbil...... mercury concentration of 4.95 nmol/g dry weight in Minamata would correspond to 668 nmol/l cord blood and 114 nmol/g maternal hair. These levels agree well with other evidence of susceptibility of the fetus to increased exposure to methylmercury....... in umbilical cord blood and in maternal hair. The results were compared with published values for mercury in umbilical cord tissue from 12 infants diagnosed with congenital methylmercury poisoning in Minamata, Japan. From the regression coefficients obtained in the Faroese samples, the median umbilical cord...

Use of microsatellite markers for identification of indigenous brown trout in a geographical region heavily influenced by stocked domesticated trout

DEFF Research Database (Denmark)

Fritzner, N.G.; Hansen, Michael Møller; Madsen, S.S.

2001-01-01

Based on estimates of genetic differentiation between populations, assignment tests and analysis of isolation by distance, stocked populations of brown trout Salmo trutta of Funen Island, Denmark, had been genetically affected by domesticated trout, whereas the stocking of wild exogenous trout...... into one of the rivers had little or no impact. At the same time, there were clear indications of remaining indigenous gene pools in the Funen populations. The management implications of these findings are discussed and changes in trout release activity are recommended to avoid further mixing of trout gene...

EVALUATION OF TOTAL MERCURY CONTENT IN MUSCLE TISSUE OF MARINE FISH AND ANIMALS

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Daniel Bajčan

2013-02-01

Full Text Available Nowdays, a degree of contamination by heavy metals can be observed in the environment. Heavy metals have serious effects on all living organisms because they can accumulate in lethal or sublethal concentrations in the various parts of food chain and so they can cause different health problems like cardiovascular and cancer diseases. Marine fish and animals are one of the bigges source of mercury in human food. Therefore this work is focused to the rate of mercury content in muscle tisuues of marine fish and animals. We analyzed mainly frozen or otherwise preserved marine fish and animals that were purchased in retail network in Slovakia. Mercury content in samples was analyzed by cold vapor AAS with mercury analyser AMA254. The contents of mercury in analysed samples were in the interval 0.0057 – 0,697 mg.kg-1. Our results shows, that no analyzed samples of marine fish and animals had over-limit concetration of Hg, so they are safe for human nutrition.

Chromosome rearrangements, recombination suppression, and limited segregation distortion in hybrids between Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri) and rainbow trout (O. mykiss)

Science.gov (United States)

2013-01-01

Background Introgressive hybridization is an important evolutionary process that can lead to the creation of novel genome structures and thus potentially new genetic variation for selection to act upon. On the other hand, hybridization with introduced species can threaten native species, such as cutthroat trout (Oncorhynchus clarkii) following the introduction of rainbow trout (O. mykiss). Neither the evolutionary consequences nor conservation implications of rainbow trout introgression in cutthroat trout is well understood. Therefore, we generated a genetic linkage map for rainbow-Yellowstone cutthroat trout (O. clarkii bouvieri) hybrids to evaluate genome processes that may help explain how introgression affects hybrid genome evolution. Results The hybrid map closely aligned with the rainbow trout map (a cutthroat trout map does not exist), sharing all but one linkage group. This linkage group (RYHyb20) represented a fusion between an acrocentric (Omy28) and a metacentric chromosome (Omy20) in rainbow trout. Additional mapping in Yellowstone cutthroat trout indicated the two rainbow trout homologues were fused in the Yellowstone genome. Variation in the number of hybrid linkage groups (28 or 29) likely depended on a Robertsonian rearrangement polymorphism within the rainbow trout stock. Comparison between the female-merged F1 map and a female consensus rainbow trout map revealed that introgression suppressed recombination across large genomic regions in 5 hybrid linkage groups. Two of these linkage groups (RYHyb20 and RYHyb25_29) contained confirmed chromosome rearrangements between rainbow and Yellowstone cutthroat trout indicating that rearrangements may suppress recombination. The frequency of allelic and genotypic segregation distortion varied among parents and families, suggesting few incompatibilities exist between rainbow and Yellowstone cutthroat trout genomes. Conclusions Chromosome rearrangements suppressed recombination in the hybrids. This result

Factors affecting competitive dominance of rainbow trout over brook trout in southern Appalachian streams: Implications of an individual-based model

Energy Technology Data Exchange (ETDEWEB)

Clark, M.E. [Univ. of Tennessee, Knoxville, TN (United States); Rose, K.A. [Oak Ridge National Lab., TN (United States)

1997-01-01

We used an individual-based model to examine possible explanations for the dominance of rainbow trout Oncorhynchus mykiss over brook trout Salvelinus fontinalis in southern Appalachian streams. Model simulations were used to quantify the effects on interspecific competition of (1) competitive advantage for feeding sites by rainbow trout, (2) latitudinal differences in stream temperatures, flows, and daylight, (3) year-class failures, (4) lower fecundity of brook trout, and (5) reductions in spawning habitat. The model tracks the daily spawning, growth, and survival of individuals of both species throughout their lifetime in a series of connected stream habitat units (pools, runs, or riffles). Average densities of each species based on 100-year simulations were compared for several levels of each of the five factors and for sympatric and allopatric conditions. Based on model results and empirical information, we conclude that more frequent year-class failures and the lower fecundity of brook trout are both possible and likely explanations for rainbow trout dominance, that warmer temperatures due to latitude and limited spawning habitat are possible but unlikely explanations, and that competitive advantage for feeding sites by rainbow trout is an unlikely explanation. Additional field work should focus on comparative studies of the reproductive success and the early life stage mortalities of brook and rainbow trout among Appalachian streams with varying rainbow trout dominance. 53 refs., 11 figs.

Maternal transfer of contaminants in birds: Mercury and selenium concentrations in parents and their eggs

Science.gov (United States)

Ackerman, Joshua T.; Eagles-Smith, Collin A.; Herzog, Mark P.; Hartman, C. Alex

2016-01-01

We conducted a detailed assessment of the maternal transfer of mercury and selenium to eggs in three bird species (n = 107 parents and n = 339 eggs), and developed predictive equations linking contaminant concentrations in eggs to those in six tissues of the mother (blood, muscle, liver, kidney, breast feathers, and head feathers). Mercury concentrations in eggs were positively correlated with mercury concentrations in each of the mother's internal tissues (R2 ≥ 0.95), but generally not with feathers. For each species, the proportion of mercury transferred to eggs decreased as mercury concentrations in the mother increased. At the same maternal mercury concentration, the proportion of mercury transferred to eggs differed among species, such that Forster's tern (Sterna forsteri) and black-necked stilt (Himantopus mexicanus) females transferred more methylmercury to their eggs than American avocet (Recurvirostra americana) females. Selenium concentrations in eggs also were correlated with selenium concentrations in the mother's liver (R2 = 0.87). Furthermore, mercury and selenium concentrations in tern eggs were positively correlated with those in the father (R2 = 0.84). Incubating male terns had 21% higher mercury concentrations in blood compared to incubating females at the same egg mercury concentration. We provide equations to predict contaminant concentrations in eggs from each of the commonly sampled bird tissues.

Identification of differentially expressed genes of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) in response to Tetracapsuloides bryosalmonae (Myxozoa).

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Kumar, Gokhlesh; Abd-Elfattah, Ahmed; El-Matbouli, Mansour

2015-03-01

Tetracapsuloides bryosalmonae Canning et al., 1999 (Myxozoa) is the causative agent of proliferative kidney disease in various species of salmonids in Europe and North America. We have shown previously that the development and distribution of the European strain of T. bryosalmonae differs in the kidney of brown trout (Salmo trutta) Linnaeus, 1758 and rainbow trout (Oncorhynchus mykiss) Walbaum, 1792, and that intra-luminal sporogonic stages were found in brown trout but not in rainbow trout. We have now compared transcriptomes from kidneys of brown trout and rainbow trout infected with T. bryosalmonae using suppressive subtractive hybridization (SSH). The differentially expressed transcripts produced by SSH were cloned, transformed, and tested by colony PCR. Differential expression screening of PCR products was validated using dot blot, and positive clones having different signal intensities were sequenced. Differential screening and a subsequent NCBI-BLAST analysis of expressed sequence tags revealed nine clones expressed differently between both fish species. These differentially expressed genes were validated by quantitative real-time PCR of kidney samples from both fish species at different time points of infection. Expression of anti-inflammatory (TSC22 domain family protein 3) and cell proliferation (Prothymin alpha) genes were upregulated significantly in brown trout but downregulated in rainbow trout. The expression of humoral immune response (immunoglobulin mu) and endocytic pathway (Ras-related protein Rab-11b) genes were significantly upregulated in rainbow trout but downregulated in brown trout. This study suggests that differential expression of host anti-inflammatory, humoral immune and endocytic pathway responses, cell proliferation, and cell growth processes do not inhibit the development of intra-luminal sporogonic stages of the European strain of T. bryosalmonae in brown trout but may suppress it in rainbow trout.

Volcanic mercury in Pinus canariensis

Science.gov (United States)

Rodríguez Martín, José Antonio; Nanos, Nikos; Miranda, José Carlos; Carbonell, Gregoria; Gil, Luis

2013-08-01

Mercury (Hg) is a toxic element that is emitted to the atmosphere by both human activities and natural processes. Volcanic emissions are considered a natural source of mercury in the environment. In some cases, tree ring records taken close to volcanoes and their relation to volcanic activity over time are contradictory. In 1949, the Hoyo Negro volcano (La Palma-Canary Islands) produced significant pyroclastic flows that damaged the nearby stand of Pinus canariensis. Recently, 60 years after the eruption, we assessed mercury concentrations in the stem of a pine which survived volcano formation, located at a distance of 50 m from the crater. We show that Hg content in a wound caused by pyroclastic impacts (22.3 μg kg-1) is an order of magnitude higher than the Hg concentrations measured in the xylem before and after the eruption (2.3 μg kg-1). Thus, mercury emissions originating from the eruption remained only as a mark—in pyroclastic wounds—and can be considered a sporadic and very high mercury input that did not affect the overall Hg input in the xylem. In addition, mercury contents recorded in the phloem (9.5 μg kg-1) and bark (6.0 μg kg-1) suggest that mercury shifts towards non-living tissues of the pine, an aspect that can be related to detoxification in volcanism-adapted species.

Volcanic mercury in Pinus canariensis.

Science.gov (United States)

Rodríguez Martín, José Antonio; Nanos, Nikos; Miranda, José Carlos; Carbonell, Gregoria; Gil, Luis

2013-08-01

Mercury (Hg) is a toxic element that is emitted to the atmosphere by both human activities and natural processes. Volcanic emissions are considered a natural source of mercury in the environment. In some cases, tree ring records taken close to volcanoes and their relation to volcanic activity over time are contradictory. In 1949, the Hoyo Negro volcano (La Palma-Canary Islands) produced significant pyroclastic flows that damaged the nearby stand of Pinus canariensis. Recently, 60 years after the eruption, we assessed mercury concentrations in the stem of a pine which survived volcano formation, located at a distance of 50 m from the crater. We show that Hg content in a wound caused by pyroclastic impacts (22.3 μg kg(-1)) is an order of magnitude higher than the Hg concentrations measured in the xylem before and after the eruption (2.3 μg kg(-1)). Thus, mercury emissions originating from the eruption remained only as a mark-in pyroclastic wounds-and can be considered a sporadic and very high mercury input that did not affect the overall Hg input in the xylem. In addition, mercury contents recorded in the phloem (9.5 μg kg(-1)) and bark (6.0 μg kg(-1)) suggest that mercury shifts towards non-living tissues of the pine, an aspect that can be related to detoxification in volcanism-adapted species.

Mercury

International Nuclear Information System (INIS)

Vilas, F.; Chapman, C.R.; Matthews, M.S.

1988-01-01

Papers are presented on future observations of and missions to Mercury, the photometry and polarimetry of Mercury, the surface composition of Mercury from reflectance spectrophotometry, the Goldstone radar observations of Mercury, the radar observations of Mercury, the stratigraphy and geologic history of Mercury, the geomorphology of impact craters on Mercury, and the cratering record on Mercury and the origin of impacting objects. Consideration is also given to the tectonics of Mercury, the tectonic history of Mercury, Mercury's thermal history and the generation of its magnetic field, the rotational dynamics of Mercury and the state of its core, Mercury's magnetic field and interior, the magnetosphere of Mercury, and the Mercury atmosphere. Other papers are on the present bounds on the bulk composition of Mercury and the implications for planetary formation processes, the building stones of the planets, the origin and composition of Mercury, the formation of Mercury from planetesimals, and theoretical considerations on the strange density of Mercury

A physiological approach to quantifying thermal habitat quality for redband rainbow trout (Oncorhynchus mykiss gairdneri) in the south Fork John Day River, Oregon

Science.gov (United States)

Feldhaus, J.W.; Heppell, S.A.; Li, H.; Mesa, M.G.

2010-01-01

We examined tissue-specific levels of heat shock protein 70 (hsp70) and whole body lipid levels in juvenile redband trout (Oncorhynchus mykiss gairdneri) from the South Fork of the John Day River (SFJD), Oregon, with the goal of determining if these measures could be used as physiological indicators of thermal habitat quality for juvenile redband trout. Our objectives were to determine the hsp70 induction temperature in liver, fin, and white muscle tissue and characterize the relation between whole body lipids and hsp70 for fish in the SFJD. We found significant increases in hsp70 levels between 19 and 22??C in fin, liver, and white muscle tissue. Maximum hsp70 levels in liver, fin, and white muscle tissue occurred when mean weekly maximum temperatures (MWMT) exceeded 20-22??C. In general, the estimated hsp70 induction temperature for fin and white muscle tissue was higher than liver tissue. Whole body lipid levels began to decrease when MWMT exceeded 20. 4??C. There was a significant interaction between temperature and hsp70 in fin and white muscle tissue, but not liver tissue. Collectively, these results suggest that increased hsp70 levels in juvenile redband trout are symptomatic of thermal stress, and that energy storage capacity decreases with this stress. The possible decrease in growth potential and fitness for thermally stressed individuals emphasizes the physiological justification for thermal management criteria in salmon-bearing streams. ?? Springer Science+Business Media B.V. 2010.

Growth rate differences between resident native brook trout and non-native brown trout

Science.gov (United States)

Carlson, S.M.; Hendry, A.P.; Letcher, B.H.

2007-01-01

Between species and across season variation in growth was examined by tagging and recapturing individual brook trout Salvelinus fontinalis and brown trout Salmo trutta across seasons in a small stream (West Brook, Massachusetts, U.S.A.). Detailed information on body size and growth are presented to (1) test whether the two species differed in growth within seasons and (2) characterize the seasonal growth patterns for two age classes of each species. Growth differed between species in nearly half of the season- and age-specific comparisons. When growth differed, non-native brown trout grew faster than native brook trout in all but one comparison. Moreover, species differences were most pronounced when overall growth was high during the spring and early summer. These growth differences resulted in size asymmetries that were sustained over the duration of the study. A literature survey also indicated that non-native salmonids typically grow faster than native salmonids when the two occur in sympatry. Taken together, these results suggest that differences in growth are not uncommon for coexisting native and non-native salmonids. ?? 2007 The Authors.

Erosion of interspecific reproductive barriers resulting from hatchery supplementation of rainbow trout sympatric with cutthroat trout.

Science.gov (United States)

Docker, Margaret F; Dale, Angie; Heath, Daniel D

2003-12-01

The frequency of hybridization between cutthroat (Onchorhynchus clarki clarki) and rainbow (O. mykiss irideus) trout from coastal habitats in British Columbia, Canada, was examined in seven populations where the two species are sympatric with no history of rainbow trout stocking and compared with areas where native rainbow trout populations have been supplemented with hatchery fish (three populations). Four nuclear markers were used to identify each species and interspecific hybrids and one mitochondrial marker showed the direction of gene exchange between species. The frequency of hybrids was significantly higher (Fisher exact test, P < 0.001) in river systems where hatchery rainbow trout have been introduced (50.6% hybrids) than in populations where the two species naturally co-occur without supplementation (9.9% hybrids).

Self poisoning in the home by mercury and its compounds

International Nuclear Information System (INIS)

Smith, H.

1982-01-01

Mercury poisoning can take place in the home. The metal may be present as a toy and the compounds as medicines or cosmetics. Unfortunately these materials are considered to be harmless and the victims do not connect the symptoms of poisoning (if recognised as such) with them. The tissue mercury levels are similar to those found in industrial exposure and as with them no relationship between symptoms and tissue concentrations can be found. (author)

Self poisoning in the home by mercury and its compounds

Energy Technology Data Exchange (ETDEWEB)

Smith, H. (Glasgow Univ. (UK). Dept. of Forensic Medicine)

1982-01-01

Mercury poisoning can take place in the home. The metal may be present as a toy and the compounds as medicines or cosmetics. Unfortunately these materials are considered to be harmless and the victims do not connect the symptoms of poisoning (if recognised as such) with them. The tissue mercury levels are similar to those found in industrial exposure and as with them no relationship between symptoms and tissue concentrations can be found.

Identification of suppressor of cytokine signalling (SOCS) 6, 7, 9 and CISH in rainbow trout Oncorhynchus mykiss and analysis of their expression in relation to other known trout SOCS.

Science.gov (United States)

Wang, Tiehui; Gao, Qian; Nie, Pin; Secombes, Christopher J

2010-10-01

Four new members of the SOCS family of molecules in rainbow trout (Oncorhynchus mykiss), CISH and SOCS6, 7 and 9, are described for the first time in this species. The genes had a wide tissue distribution in trout, and were detected in gills, skin, muscle, liver, spleen, head kidney, intestine and brain, with brain having the highest expression levels. Stimulation of a rainbow trout leucocyte cell line, RTS-11, (mononuclear/macrophage-like cells) with LPS or Poly I:C had no effect on the expression of these genes, although in both cases the previously identified SOCS1-3 genes were up-regulated. Similarly, stimulation of RTS-11 or RTG-2 (fibroblasts) cells with the trout recombinant cytokines IFN-gamma or IL-1beta had no effect on CISH or SOCS6, 7 and 9 expression. However, PMA stimulation did impact on SOCS6 and SOCS9 expression, and LPS stimulation of primary cultures or bacterial infection (Yersinia ruckeri) increased significantly CISH expression (as well as SOCS1 and SOCS2 or SOCS3 respectively). It is apparent that the type II SOCS genes (CISH, SOCS1-3) are particularly relevant to immune regulation in fish, although the intriguing expansion of the SOCS4/5 subgroup in fish requires further investigation as to their role and functional divergence. Copyright 2010 Elsevier Ltd. All rights reserved.

Feeding habits of the alien brook trout Salvelinus fontinalis and the native brown trout Salmo trutta in Czech mountain streams

Directory of Open Access Journals (Sweden)

Horká Petra

2017-01-01

Full Text Available Quantifying patterns of prey resource use is fundamental to identify mechanisms enabling the coexistence of related fish species. Trophic interactions between the native brown trout, Salmo trutta, and the introduced brook trout, Salvelinus fontinalis, were studied monthly from May to October in three mountain streams in Central Europe (Czech Republic. To evaluate whether the feeding habits differ between separated and coexisting populations of these species, one locality where both species coexist, and two allopatric populations of either species were studied. Across the study period, the mean stomach fullness of fish varied, being highest in spring and declining through autumn. The diet overlap (Schoener's overlap index between the species increased through the studied season (from 54.5% in July to 81.5% in October. In allopatry, both species had nearly the same feeding habits. However, in sympatry, brook trout consumed higher proportion of terrestrial invertebrates, while brown trout showed no changes either in the proportions of aquatic and terrestrial prey utilized or in the selectivity for prey categories in comparison to allopatric conditions. The dietary shift observed for brook trout, but not for brown trout, suggests that brown trout is a stronger competitor in the studied sympatric locality, leading the brook trout to change its feeding habits to reduce interspecific competition.

Admixture analysis of stocked brown trout populations using mapped microsatellite DNA markers: indigenous trout persist in introgressed populations

DEFF Research Database (Denmark)

Hansen, Michael Møller; Mensberg, Karen-Lise Dons

2009-01-01

, but resolution is low if genetic differentiation is weak. Here, we analyse stocked brown trout populations represented by historical (1943-1956) and contemporary (2000s) samples, where genetic differentiation between wild populations and stocked trout is weak (pair-wise F-ST of 0.047 and 0.053). By analysing...... a high number of microsatellite DNA markers (50) and making use of linkage map information, we achieve clear identification of admixed and non-admixed trout. Moreover, despite strong population-level admixture by hatchery strain trout in one of the populations (70.8%), non-admixed individuals...... nevertheless persist (7 out of 53 individuals). These remnants of the indigenous population are characterized by later spawning time than the majority of the admixed individuals. We hypothesize that isolation by time mediated by spawning time differences between wild and hatchery strain trout is a major factor...

Effects of sex steroids, sex, and sexual maturity on cortisol production: an in vitro comparison of chinook salmon and rainbow trout interrenals.

Science.gov (United States)

McQuillan, H James; Lokman, P Mark; Young, Graham

2003-08-01

Sex steroids appear to be responsible for hyperactivation of the hypothalamus-pituitary-interrenal (HPI) axis that occurs in mature semelparous Pacific salmon as a prelude to post-spawning (programmed) death. This study was undertaken to examine the direct effects of sex steroids on interrenal activity of semelparous (chinook salmon) and iteroparous (rainbow trout) salmonids using an in vitro incubation system. In addition, phenotypic sex differences in cortisol production by interrenals of sexually mature (spawning) rainbow trout and chinook salmon were investigated. Interrenal tissue from juvenile and sexually mature chinook salmon and rainbow trout was incubated for 48 h in culture medium containing either no steroid (controls), 1 microM estradiol (E2) or 1 microM 11-ketotestosterone (11-KT). This tissue was then challenged for 3h with either pregnenolone, dibutyryladenosine 3('):5(')-cyclic monophosphate (dbcAMP) or forskolin, or synthetic human adrenocorticotropic hormone (ACTH(1-24)). Sex differences in in vitro interrenal cortisol production were assessed using separate tissue pools challenged with the same agents. Cortisol in media was measured by radioimmunoassay. E2 suppressed the ability of juvenile chinook salmon interrenals to utilize pregnenolone as substrate for cortisol synthesis. In mature female chinook salmon the suppressive effect of E2 was less pronounced, but was observed as a reduced response of interrenals to both pregnenolone and dbcAMP. E2 did not affect ACTH(1-24) stimulated cortisol production. Immature and mature rainbow trout interrenals were both relatively insensitive to E2. 11-KT did not affect cortisol production by juvenile chinook salmon and juvenile or mature rainbow trout, and had only minor effects in male and female spawning chinook salmon. In mature chinook salmon and rainbow trout, the interrenals of females were more responsive to ACTH stimulation and showed a greater utilization of pregnenolone as a substrate than

Effect of a Peracetic Acid-Based Disinfectant on Growth, Hematology and Histology of Juvenile Rainbow Trout (Oncorhynchus mykiss

Directory of Open Access Journals (Sweden)

Ramtin Hushangi

2018-02-01

Full Text Available The effects of a peracetic acid-based disinfectant product (Aquastart® were assessed on some hematological parameters, histological aspects and skin bacterial load of rainbow trout, likewise bacterial load of the rearing tank water. A total of 180 healthy rainbow trout weighing 124.65 ± 10 g were divided into two groups, each in three replicates in flow-through tanks. First group was exposed to Aquastart at 8.9 ppm for 30 min and second group was considered as the control. The fish were then reared for 60 days prior to sampling for hematological and histological studies. The lowest bacterial load level in both water columns and trout skin were observed in the treated trout (p < 0.05. Meanwhile, no significant impact on growth performance was recorded between treated and control fish. The immunocompetent cells population size in control fish were significantly lower than treated fish (p < 0.05. Histologically, no evidence of abnormality was seen in the gills, kidney, and liver tissues of treated fish. These results showed that application of Aquastart at 8.9 ppm is safe for use in flow-through tanks farming rainbow trout.

Cadmium, mercury, zinc and selenium in ringed seals (Phoca hispida from Greenland and Svalbard

Directory of Open Access Journals (Sweden)

Run Dietz

1998-06-01

Full Text Available Muscle, liver, and kidney tissue from 456 ringed seals (Phoca hispida from eight areas in Greenland were analysed for cadmium, mercury, zinc and selenium. In general, cadmium concentrations were high in liver and kidney tissue, with geometric means of 7.79 and 33.5 μg/g (all data on wet weight basis, respectively. Muscle levels were considerably lower, at 0.067 μg/g. The concentration of mercury was relatively high in liver tissue with a geometric mean of 2.59 μg/g. Muscle and kidney mercury levels were somewhat lower, with geometric means of 0.210 and 0.956 μg/g, respectively. Cadmium and mercury levels were strongly dependent upon age and sampling area, as well as the interaction combinations, indicating that the accumulation of cadmium and mercury varies with age and area. Mercury accumulated in all three tissues throughout life, whereas cadmium in liver and kidneys peaked in the age group 5-10 years old where after it dropped significantly. Cadmium levels showed a tendency towards higher concentrations in the northern municipalities, which may be due to the higher cadmium levels in certain prey items in the northern areas. Mercury levels were higher in seals from East Greenland compared to West Greenland. Variations in feeding habits probably explain some of the differences in levels of cadmium and mercury in ringed seals from different geographical areas. Cadmium concentrations were correlated (both pairwise and partial in the three organs. This was true for mercury as well, whereas only half of the combinations were significant for zinc and selenium. Cadmium was strongly correlated to mercury in all three tissues and zinc only in liver and kidneys. Mercury was only correlated to selenium in liver and not to zinc. High concentrations of cadmium were found in the bile from 58 ringed seals, and were about 10-fold higher than in muscle. The concentration of mercury in bile was relatively low, being only one third of the

Brown trout and food web interactions in a Minnesota stream

Science.gov (United States)

Zimmerman, J.K.H.; Vondracek, B.

2007-01-01

1. We examined indirect, community-level interactions in a stream that contained non-native brown trout (Salmo trutta Linnaeus), native brook trout (Salvelinus fontinalis Mitchill) and native slimy sculpin (Cottus cognatus Richardson). Our objectives were to examine benthic invertebrate composition and prey selection of fishes (measured by total invertebrate dry mass, dry mass of individual invertebrate taxa and relative proportion of invertebrate taxa in the benthos and diet) among treatments (no fish, juvenile brook trout alone, juvenile brown trout alone, sculpin with brook trout and sculpin with brown trout). 2. We assigned treatments to 1 m2 enclosures/exclosures placed in riffles in Valley Creek, Minnesota, and conducted six experimental trials. We used three designs of fish densities (addition of trout to a constant number of sculpin with unequal numbers of trout and sculpin; addition of trout to a constant number of sculpin with equal numbers of trout and sculpin; and replacement of half the sculpin with an equal number of trout) to investigate the relative strength of interspecific versus intraspecific interactions. 3. Presence of fish (all three species, alone or in combined-species treatments) was not associated with changes in total dry mass of benthic invertebrates or shifts in relative abundance of benthic invertebrate taxa, regardless of fish density design. 4. Brook trout and sculpin diets did not change when each species was alone compared with treatments of both species together. Likewise, we did not find evidence for shifts in brown trout or sculpin diets when each species was alone or together. 5. We suggest that native brook trout and non-native brown trout fill similar niches in Valley Creek. We did not find evidence that either species had an effect on stream communities, potentially due to high invertebrate productivity in Valley Creek. ?? 2007 Blackwell Publishing Ltd.

Production and evaluation of YY-male Brook Trout to eradicate nonnative wild brook trout populations

Science.gov (United States)

Kennedy, Patrick; Schill, Daniel J.; Meyer, Kevin A.; Campbell, Matthew R.; Vu, Ninh V.; Hansen, Michael J.

2017-01-01

Nonnative Brook Trout Salvelinus fontinalis were introduced throughout western North America in the early 1900s, resulting in widespread self-sustaining populations that are difficult to eradicate and often threaten native salmonid populations. A novel approach for their eradication involves use of YY male (MYY) Brook Trout (created in the hatchery by feminizing XY males and crossing them with normal XY males). If MYY Brook Trout survive after stocking, and reproduce successfully with wild females, in theory this could eventually drive the sex ratio of the wild population to 100% males, at which point the population would not be able to reproduce and would be eradicated. This study represents the first successful development of a FYY and MYY salmonid broodstock, which was produced in four years at relatively low cost. Field trials demonstrated that stocked hatchery MYY Brook Trout survived and produced viable MYY offspring in streams, although reproductive fitness appeared to have been lower than their wild conspecifics. Even if reduced fitness is the norm in both streams and alpine lakes, our population simulations suggest that eradication can be achieved in reasonable time periods under some MYY stocking scenarios, especially when wild Brook Trout are simultaneously suppressed in the population.

Immune-Specific Expression and Estrogenic Regulation of the Four Estrogen Receptor Isoforms in Female Rainbow Trout (Oncorhynchus mykiss

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Ayako Casanova-Nakayama

2018-03-01

Full Text Available Genomic actions of estrogens in vertebrates are exerted via two intracellular estrogen receptor (ER subtypes, ERα and ERβ, which show cell- and tissue-specific expression profiles. Mammalian immune cells express ERs and are responsive to estrogens. More recently, evidence became available that ERs are also present in the immune organs and cells of teleost fish, suggesting that the immunomodulatory function of estrogens has been conserved throughout vertebrate evolution. For a better understanding of the sensitivity and the responsiveness of the fish immune system to estrogens, more insight is needed on the abundance of ERs in the fish immune system, the cellular ratios of the ER subtypes, and their autoregulation by estrogens. Consequently, the aims of the present study were (i to determine the absolute mRNA copy numbers of the four ER isoforms in the immune organs and cells of rainbow trout, Oncorhynchus mykiss, and to compare them to the hepatic ER numbers; (ii to analyse the ER mRNA isoform ratios in the immune system; and, (iii finally, to examine the alterations of immune ER mRNA expression levels in sexually immature trout exposed to 17β-estradiol (E2, as well as the alterations of immune ER mRNA expression levels in sexually mature trout during the reproductive cycle. All four ER isoforms were present in immune organs—head kidney, spleen-and immune cells from head kidney and blood of rainbow trout, but their mRNA levels were substantially lower than in the liver. The ER isoform ratios were tissue- and cell-specific, both within the immune system, but also between the immune system and the liver. Short-term administration of E2 to juvenile female trout altered the ER mRNA levels in the liver, but the ERs of the immune organs and cells were not responsive. Changes of ER gene transcript numbers in immune organs and cells occurred during the reproductive cycle of mature female trout, but the changes in the immune ER profiles differed

Auto-aggressive metallic mercury injection around the knee joint: a case report

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Friesenbichler Joerg

2011-11-01

Full Text Available Abstract Background Accidental or intentional subcutaneous and/or intramuscular injection of metallic mercury is an uncommon form of poisoning. Although it does not carry the same risk as mercury vapour inhalation, it may cause destructive early and late reactions. Case Presentation Herein we present the case of a 29-year-old male patient who developed an obsessive-compulsive disorder causing auto-aggressive behaviour with injection of elemental mercury and several other foreign bodies into the soft tissues around the left knee about 15 years before initial presentation. For clinical examination X-rays and a CT-scan of the affected area were performed. Furthermore, blood was taken to determine the mercury concentration in the blood, which showed a concentration 17-fold higher than recommended. As a consequence, the mercury depots and several foreign bodies were resected marginally. Conclusion Blood levels of mercury will decrease rapidly following surgery, especially in combination with chelating therapy. In case of subcutaneous and intramuscular injection of metallic mercury we recommend marginal or wide excision of all contaminated tissue to prevent migration of mercury and chronic inflammation. Nevertheless, prolonged clinical and biochemical monitoring should be performed for several years to screen for chronic intoxication.

Levels of arsenic, cadmium, lead and mercury in the branchial plate and muscle tissue of mobulid rays

International Nuclear Information System (INIS)

Ooi, Michelle S.M.; Townsend, Kathy A.; Bennett, Michael B.; Richardson, Anthony J.; Fernando, Daniel; Villa, Cesar A.; Gaus, Caroline

2015-01-01

Highlights: • Branchial plate and muscle tissue from mobulid rays were analysed for certain metals. • Mean concentrations of cadmium in Mobula japanica were above the EC ML. • Mean inorganic arsenic concentration in Mobula japanica muscle equalled the FSANZ ML. • Mean concentration of lead in Manta alfredi muscle tissue exceeded EC and Codex MLs. • There were significant correlations between the types of tissues for some metals. - Abstract: Mobulid rays are targeted in fisheries for their branchial plates, for use in Chinese medicine. Branchial plate and muscle tissue from Mobula japanica were collected from fish markets in Sri Lanka, and muscle tissue biopsies from Manta alfredi in Australia. These were analysed for arsenic, cadmium, lead and mercury and compared to maximum levels (MLs) set by Food Standards Australia and New Zealand (FSANZ), European Commission (EC) and Codex Alimentarius Commission. The estimated intake for a vulnerable human age group was compared to minimal risk levels set by the Agency for Toxic Substances and Disease Registry. The mean inorganic arsenic concentration in M. japanica muscle was equivalent to the FSANZ ML while cadmium exceeded the EC ML. The mean concentration of lead in M. alfredi muscle tissue exceeded EC and Codex MLs. There were significant positive linear correlations between branchial plate and muscle tissue concentrations for arsenic, cadmium and lead

Selenium: Mercury Molar Ratios in Freshwater Fish in the Columbia River Basin: Potential Applications for Specific Fish Consumption Advisories.

Science.gov (United States)

Cusack, Leanne K; Eagles-Smith, Collin; Harding, Anna K; Kile, Molly; Stone, Dave

2017-07-01

Fish provide a valuable source of beneficial nutrients and are an excellent source of low fat protein. However, fish are also the primary source of methylmercury exposure in humans. Selenium often co-occurs with mercury and there is some evidence that selenium can protect against mercury toxicity yet States issue fish consumption advisories based solely on the risks that methylmercury pose to human health. Recently, it has been suggested the selenium: mercury molar ratio be considered in risk management. In order for agencies to utilize the ratio to set consumption guidelines, it is important to evaluate the variability in selenium and mercury in different fish species. We examined 10 different freshwater fish species found within the Columbia River Basin in order to determine the inter- and intra-specific variability in the selenium: mercury molar ratios and the selenium health benefit values. We found significant variation in selenium: mercury molar ratios. The mean molar ratios for each species were all above 1:1, ranging from 3.42:1 in Walleye to 27.2:1 in Chinook salmon. There was a positive correlation between both mercury and selenium with length for each fish species apart from yellow perch and rainbow trout. All species had health benefit values greater than 2. We observed considerable variability in selenium: mercury molar ratios within fish species collected in the Columbia River Basin. Although incorporating selenium: mercury molar ratios into fish consumption holds the potential for refining advisories and assessing the risk of methylmercury exposure, the current understanding of how these ratios apply is insufficient, and further understanding of drivers of variability in the ratios is needed.

Selenium: Mercury molar ratios in freshwater fish in the Columbia River Basin: Potential applications for specific fish consumption advisories

Science.gov (United States)

Cusack, Leanne K.; Eagles-Smith, Collin A.; Harding, Anna K.; Kile, Molly; Stone, Dave

2017-01-01

Fish provide a valuable source of beneficial nutrients and are an excellent source of low fat protein. However, fish are also the primary source of methylmercury exposure in humans. Selenium often co-occurs with mercury and there is some evidence that selenium can protect against mercury toxicity yet States issue fish consumption advisories based solely on the risks that methylmercury pose to human health. Recently, it has been suggested the selenium: mercury molar ratio be considered in risk management. In order for agencies to utilize the ratio to set consumption guidelines, it is important to evaluate the variability in selenium and mercury in different fish species. We examined 10 different freshwater fish species found within the Columbia River Basin in order to determine the inter- and intra-specific variability in the selenium: mercury molar ratios and the selenium health benefit values. We found significant variation in selenium: mercury molar ratios. The mean molar ratios for each species were all above 1:1, ranging from 3.42:1 in Walleye to 27.2:1 in Chinook salmon. There was a positive correlation between both mercury and selenium with length for each fish species apart from yellow perch and rainbow trout. All species had health benefit values greater than 2. We observed considerable variability in selenium: mercury molar ratios within fish species collected in the Columbia River Basin. Although incorporating selenium: mercury molar ratios into fish consumption holds the potential for refining advisories and assessing the risk of methylmercury exposure, the current understanding of how these ratios apply is insufficient, and further understanding of drivers of variability in the ratios is needed.

Mercury exposure may influence fluctuating asymmetry in waterbirds

Science.gov (United States)

Herring, Garth; Eagles-Smith, Collin A.; Ackerman, Joshua T.

2017-01-01

Variation in avian bilateral symmetry can be an indicator of developmental instability in response to a variety of stressors, including environmental contaminants. The authors used composite measures of fluctuating asymmetry to examine the influence of mercury concentrations in 2 tissues on fluctuating asymmetry within 4 waterbird species. Fluctuating asymmetry increased with mercury concentrations in whole blood and breast feathers of Forster's terns (Sterna forsteri), a species with elevated mercury concentrations. Specifically, fluctuating asymmetry in rectrix feather 1 was the most strongly correlated structural variable of those tested (wing chord, tarsus, primary feather 10, rectrix feather 6) with mercury concentrations in Forster's terns. However, for American avocets (Recurvirostra americana), black-necked stilts (Himantopus mexicanus), and Caspian terns (Hydroprogne caspia), the authors found no relationship between fluctuating asymmetry and either whole-blood or breast feather mercury concentrations, even though these species had moderate to elevated mercury exposure. The results indicate that mercury contamination may act as an environmental stressor during development and feather growth and contribute to fluctuating asymmetry of some species of highly contaminated waterbirds.

Investigations of bull trout (Salvelinus confluentus), steelhead trout (Oncorhynchus mykiss), and spring chinook salmon (O. tshawytscha) interactions in Southeast Washington streams. Final report 1992

International Nuclear Information System (INIS)

Underwood, K.D.; Martin, S.W.; Schuck, M.L.; Scholz, A.T.

1995-01-01

The goal of this two year study was to determine if supplementation with hatchery reared steelhead trout (Oncorhynchus mykiss) and spring chinook salmon (O. tshawytscha) negatively impacted wild native bull trout (Salvelinus confluentus) through competitive interactions. Four streams with varying levels of fish supplementation activity were sampled in Southeast Washington. Tasks performed during this study were population density, relative abundance, microhabitat utilization, habitat availability, diet analysis, bull trout spawning ground surveys, radio telemetry of adult bull trout, and growth analysis. Results indicate that bull trout overlapped geographically with the supplemented species in each of the study streams suggesting competition among species was possible. Within a stream, bull trout and the supplemented species utilized dissimilar microhabitats and microhabitat utilization by each species was the same among streams suggesting that there was no shifts in microhabitat utilization among streams. The diet of bull trout and O. mykiss significantly overlapped in each of the study streams. The stream most intensely supplemented contained bull trout with the slowest growth and the non-supplemented stream contained bull trout with the fastest growth. Conversely, the stream most intensely supplemented contain steelhead with the fastest growth and the non-supplemented stream contained steelhead with the slowest growth. Growth indicated that bull trout may have been negatively impacted from supplementation, although other factors may have contributed. At current population levels, and current habitat quantity and quality, no impacts to bull trout as a result of supplementation with hatchery reared steelhead trout and spring chinook salmon were detected. Project limitations and future research recommendations are discussed

Investigations of Bull Trout (Salvelinus Confluentus), Steelhead Trout (Oncorhynchus Mykiss), and Spring Chinook Salmon (O. Tshawytscha) Interactions in Southeast Washington Streams. Final Report 1992.

Energy Technology Data Exchange (ETDEWEB)

Underwood, Keith D.

1995-01-01

The goal of this two year study was to determine if supplementation with hatchery reared steelhead trout (Oncorhynchus mykiss) and spring chinook salmon (O. tshawytscha) negatively impacted wild native bull trout (Salvelinus confluentus) through competitive interactions. Four streams with varying levels of fish supplementation activity were sampled in Southeast Washington. Tasks performed during this study were population density, relative abundance, microhabitat utilization, habitat availability, diet analysis, bull trout spawning ground surveys, radio telemetry of adult bull trout, and growth analysis. Results indicate that bull trout overlapped geographically with the supplemented species in each of the study streams suggesting competition among species was possible. Within a stream, bull trout and the supplemented species utilized dissimilar microhabitats and microhabitat utilization by each species was the same among streams suggesting that there was no shifts in microhabitat utilization among streams. The diet of bull trout and O. mykiss significantly overlapped in each of the study streams. The stream most intensely supplemented contained bull trout with the slowest growth and the non-supplemented stream contained bull trout with the fastest growth. Conversely, the stream most intensely supplemented contain steelhead with the fastest growth and the non-supplemented stream contained steelhead with the slowest growth. Growth indicated that bull trout may have been negatively impacted from supplementation, although other factors may have contributed. At current population levels, and current habitat quantity and quality, no impacts to bull trout as a result of supplementation with hatchery reared steelhead trout and spring chinook salmon were detected. Project limitations and future research recommendations are discussed.

Effects of water temperature and fish size on predation vulnerability of juvenile humpback chub to rainbow trout and brown trout

Science.gov (United States)

Ward, David L.; Morton-Starner, Rylan

2015-01-01

Predation on juvenile native fish by introduced Rainbow Trout and Brown Trout is considered a significant threat to the persistence of endangered Humpback Chub Gila cypha in the Colorado River in the Grand Canyon. Diet studies of Rainbow Trout and Brown Trout in Glen and Grand canyons indicate that these species do eat native fish, but impacts are difficult to assess because predation vulnerability is highly variable, depending on prey size, predator size, and the water temperatures under which the predation interactions take place. We conducted laboratory experiments to evaluate how short-term predation vulnerability of juvenile native fish changes in response to fish size and water temperature using captivity-reared Humpback Chub, Bonytail, and Roundtail Chub. Juvenile chub 45–90 mm total length (TL) were exposed to adult Rainbow and Brown trouts at 10, 15, and 20°C to measure predation vulnerability as a function of water temperature and fish size. A 1°C increase in water temperature decreased short-term predation vulnerability of Humpback Chub to Rainbow Trout by about 5%, although the relationship is not linear. Brown Trout were highly piscivorous in the laboratory at any size > 220 mm TL and at all water temperatures we tested. Understanding the effects of predation by trout on endangered Humpback Chub is critical in evaluating management options aimed at preserving native fishes in Grand Canyon National Park.

Distribution and elimination of [14C]octachlorostyrene in cod (Gadus morhua), rainbow trout (Salmo gairdneri), and blue mussel (Mytilus edulis)

International Nuclear Information System (INIS)

Ingebrigtsen, K.; Solbakken, J.E.; Norheim, G.; Nafstad, I.

1988-01-01

Cod (Gadus morhua) and rainbow trout (Salmo gairdneri) were given a single oral dose of 100 microCi/kg b.w. of [ 14 C]octachlorostyrene [( 14 C]OCS) in peanut oil. Blue mussel (Mytilus edulis) was exposed to [ 14 C]OCS in water. The distribution and elimination of the compound was studied by liquid scintillation counting and whole-body autoradiography. The highest degree of radioactivity in the cod and rainbow trout was measured in the liver and the visceral fat, respectively. The degree of radioactivity in the brain of cod exceeded that of the rainbow trout by a factor between 2 and 4 at all survival times. In addition to bile excretion of [ 14 C]OCS-derived radioactivity, a possible excretion over the intestinal mucosa was suggested. The rate of elimination was slow in both species, and substantial amounts of radioactivity remained in the tissues 90 d after administration. In the blue mussel, the highest degree of radioactivity was found in the hepatopancreas. Substantial amounts of radioactivity were present in the mussel tissues 60 d after administration

Critical comparison of intravenous injection of TiO2 nanoparticles with waterborne and dietary exposures concludes minimal environmentally-relevant toxicity in juvenile rainbow trout Oncorhynchus mykiss

International Nuclear Information System (INIS)

Boyle, David; Al-Bairuty, Genan A.; Henry, Theodore B.; Handy, Richard D.

2013-01-01

A critical comparison of studies that have investigated tissue accumulation and toxicity of TiO 2 -NPs in fish is necessary to resolve inconsistencies. The present study used identical TiO 2 -NPs, toxicological endpoints, and fish (juvenile rainbow trout Oncorhynchus mykiss) as previous studies that investigated waterborne and dietary toxicity of TiO 2 -NPs, and conducted a critical comparison of results after intravenous caudal-vein injection of 50 μg of TiO 2 -NPs and bulk TiO 2 . Injected TiO 2 -NPs accumulated only in kidney (94% of measured Ti) and to a lesser extent in spleen; and injected bulk TiO 2 was found only in kidney. No toxicity of TiO 2 was observed in kidney, spleen, or other tissues. Critical comparison of these data with previous studies indicates that dietary and waterborne exposures to TiO 2 -NPs do not lead to Ti accumulation in internal tissues, and previous reports of minor toxicity are inconsistent or attributable to respiratory distress resulting from gill occlusion during waterborne exposure. -- Highlights: •Critical comparison of TiO 2 -NP toxicity studies in rainbow trout. •No evidence of TiO 2 -NP absorption in internal tissues. •Conclude minimal environmentally relevant toxicity of TiO 2 -NPs in rainbow trout. -- Critical evaluation of directly comparable investigations of TiO 2 -NP toxicity by waterborne, dietary, and intravenous injection exposures conclude minimal toxicity in juvenile rainbow trout

Investigations of Bull Trout (Salvelinus Confluentus), Steelhead Trout (Oncorhynchus Mykiss), and Spring Chinook Salmon (O. Tshawytscha) Interactions in Southeast Washington Streams : 1991 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Martin, Steven W.

1992-07-01

Bull trout (Salvelinus confluentus) are native to many tributaries of the Snake River in southeast Washington. The Washington Department of Wildlife (WDW) and the American Fisheries Society (AFS) have identified bull trout as a species of special concern which means that they may become threatened or endangered by relatively, minor disturbances to their habitat. Steelhead trout/rainbow trout (Oncorhynchus mykiss) and spring chinook salmon (O.tshawytscha) are also native to several tributaries of the Snake river in southeast Washington. These species of migratory fishes are depressed, partially due to the construction of several dams on the lower Snake river. In response to decreased run size, large hatchery program were initiated to produce juvenile steelhead and salmon to supplement repressed tributary stocks, a practice known as supplementation. There is a concern that supplementing streams with artificially high numbers of steelhead and salmon may have an impact on resident bull trout in these streams. Historically, these three species of fish existed together in large numbers, however, the amount of high-quality habitat necessary for reproduction and rearing has been severely reduced in recent years, as compared to historic amounts. The findings of the first year of a two year study aimed at identifying species interactions in southeast Washington streams are presented in this report. Data was collected to assess population dynamics; habitat utilization and preference, feeding habits, fish movement and migration, age, condition, growth, and the spawning requirements of bull trout in each of four streams. A comparison of the indices was then made between the study streams to determine if bull trout differ in the presence of the putative competitor species. Bull trout populations were highest in the Tucannon River (supplemented stream), followed by Mill Creek (unsupplemented stream). Young of the year bull trout utilized riffle and cascade habitat the most in all

PATHOGENECITY OF GROUPER SLEEPY DISEASE IRIDOVIRUS (GSDIV: Megalocytivirus, FAMILY Iridoviridae TO CORAL TROUT GROUPER Plectrophomus leopardus

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Ketut Mahardika

2009-12-01

Full Text Available Grouper sleepy disease iridovirus (GSDIV, a member of the genus Megalocytivirus in the family Iridoviridae, has been known to cause large scale mortalities resulting in severe economic losses in grouper industries in south-east Asia including Indonesia. In this study, experimental infection of coral trout grouper Plectrophomus indicus with GSDIV was performed to evaluate the viral pathogenecity to this fish species. After virus exposure, the mortalities of coral trout grouper injected with primary and 10-1 dilution of spleen homogenates derived from tiger grouper Epinephelus fuscoguttatus were 100% and 90%, respectively. Histopathology revealed that moribund fish receiving GSDIV inoculum displayed massive formation of enlarged cells in the spleen and hematopoitic tissues. Under electron microscopy, the enlarged cells were observed as inclusion body bearing cells (IBCs and necrotic cells allowing virus propagation within an intracytoplasmic virus assembly site (VAS. GSDIV virions were 167-200 nm in size. These findings confirmed that GSDIV has severe pathogenicity to coral trout grouper and IBCs as well as necrotic cells were determined to be the pathognomonic sign of megalocytivirus-infected coral trout grouper.

Maternal transfer of contaminants in birds: Mercury and selenium concentrations in parents and their eggs

International Nuclear Information System (INIS)

Ackerman, Joshua T.; Eagles-Smith, Collin A.; Herzog, Mark P.; Hartman, C. Alex

2016-01-01

We conducted a detailed assessment of the maternal transfer of mercury and selenium to eggs in three bird species (n = 107 parents and n = 339 eggs), and developed predictive equations linking contaminant concentrations in eggs to those in six tissues of the mother (blood, muscle, liver, kidney, breast feathers, and head feathers). Mercury concentrations in eggs were positively correlated with mercury concentrations in each of the mother's internal tissues (R"2 ≥ 0.95), but generally not with feathers. For each species, the proportion of mercury transferred to eggs decreased as mercury concentrations in the mother increased. At the same maternal mercury concentration, the proportion of mercury transferred to eggs differed among species, such that Forster's tern (Sterna forsteri) and black-necked stilt (Himantopus mexicanus) females transferred more methylmercury to their eggs than American avocet (Recurvirostra americana) females. Selenium concentrations in eggs also were correlated with selenium concentrations in the mother's liver (R"2 = 0.87). Furthermore, mercury and selenium concentrations in tern eggs were positively correlated with those in the father (R"2 = 0.84). Incubating male terns had 21% higher mercury concentrations in blood compared to incubating females at the same egg mercury concentration. We provide equations to predict contaminant concentrations in eggs from each of the commonly sampled bird tissues. - Highlights: • We developed predictive equations linking contaminant concentrations in eggs to those in the mother. • Mercury concentrations in eggs were positively correlated with those in the mother. • The proportion of mercury transferred to eggs decreased as mercury in the mother increased. • The proportion of mercury transferred to eggs differed among species. • Selenium concentrations in eggs also were correlated with those in the mother's liver. - We examined the maternal transfer of mercury and selenium to eggs in

Heavy metal residues in tissues of marine turtles

International Nuclear Information System (INIS)

Storelli, M.M.; Marcotrigiano, G.O.

2003-01-01

Heavy metal concentrations in the tissues of marine turtles are presented. The most frequently monitored elements are mercury, cadmium and lead; and the tissues mainly analysed in nearly all the stranded individuals are muscle, liver and kidney. The highest mercury and cadmium levels were found in liver and kidney respectively; the majority of the lead burden existed in bones and carapace, while arsenic was present mainly in muscle tissue. Mercury occurred quite completely as methylmercury in muscle, whereas in liver the main form was the inorganic one. Arsenic was exclusively present in the metallorganic form either in muscle tissue or in liver. Metals in the eggs were mainly present in the yolk. Significantly higher concentration of mercury, copper, zinc and iron were found in yolk than albumen, while shell contained highest levels of manganese and copper. The load of trace metals in these animals strictly correlated with the species seems to depend on their different food behaviour

Heavy metal residues in tissues of marine turtles

Energy Technology Data Exchange (ETDEWEB)

Storelli, M.M.; Marcotrigiano, G.O

2003-04-01

Heavy metal concentrations in the tissues of marine turtles are presented. The most frequently monitored elements are mercury, cadmium and lead; and the tissues mainly analysed in nearly all the stranded individuals are muscle, liver and kidney. The highest mercury and cadmium levels were found in liver and kidney respectively; the majority of the lead burden existed in bones and carapace, while arsenic was present mainly in muscle tissue. Mercury occurred quite completely as methylmercury in muscle, whereas in liver the main form was the inorganic one. Arsenic was exclusively present in the metallorganic form either in muscle tissue or in liver. Metals in the eggs were mainly present in the yolk. Significantly higher concentration of mercury, copper, zinc and iron were found in yolk than albumen, while shell contained highest levels of manganese and copper. The load of trace metals in these animals strictly correlated with the species seems to depend on their different food behaviour.

Depletion of isoeugenol residues from the fillet tissue of AQUI-S™ exposed rainbow trout (Oncorhynchus mykiss)

Science.gov (United States)

Meinertz, Jeffery R.; Schreier, Theresa M.

2009-01-01

There is a critical need in U.S. public aquaculture and fishery management for an approved sedative that allows for the immediate release of fish after sedation. AQUI-STM is a fish anesthetic/sedative approved for use in several countries and until recently was being developed in the U.S. as a sedative for immediate release of fish after sedation. The U.S. National Toxicology Program reported that isoeugenol (the active ingredient in AQUI-STM) exposed male mice showed clear evidence of carcinogenicity, therefore efforts within the U.S. Department of Interior to develop AQUI-STM as a sedative that allows for immediate release ceased. Despite the ruling, AQUI-STM still has the potential to be approved as an anesthetic with a short withdrawal time. Among the data required to gain approval for use in the U.S. are data describing the composition and depletion of all AQUI-STM residues from fish fillet tissue. A total residue depletion study for AQUI-STM was conducted by exposing market-sized rainbow trout, Oncorhynchus mykiss (mean weight, 502.7 ± 54 g; s.d.) to 8.9 mg/L of 14C-[URL]-isoeugenol for 60 min in 17 °C water. The 14C-[URL]-isoeugenol was mixed with a surfactant resulting in a mixture that mimicked AQUI-STM. Groups of fish (n = 6) were sampled immediately after the exposure (0-h sample group) and at 0.5, 1, 2, and 4 h thereafter. Total isoeugenol-equivalent residue concentrations in the fillet tissue were determined by oxidizing triplicate subsamples of homogenized skin-on fillet tissue from each fish to 14CO2 and enumerating the radioactivity by static liquid scintillation counting. Isoeugenol concentrations in fillet tissue were determined by extracting homogenized fillet tissue with solvents and determining the isoeugenol concentrations in the extracts with high performance liquid chromatography techniques. The mean total isoeugenol-equivalent residue concentrations in the 0, 0.5, 1, 2, and 4-h sample groups were 55.4, 32.0, 19.8, 11

Mercury bioaccumulation assessment for the St. Louis River Area of Concern

Science.gov (United States)

Both Minnesota and Wisconsin have posted fish consumption advisories within the St. Louis River Area of Concern (SLR AOC), in part because fish have elevated mercury concentrations. To assess mercury concentrations in fish tissue within the SLR AOC relative to reference condition...

Lead, mercury, cadmium, chromium, and arsenic levels in eggs, feathers, and tissues of Canada geese of the New Jersey Meadowlands

International Nuclear Information System (INIS)

Tsipoura, Nellie; Burger, Joanna; Newhouse, Michael; Jeitner, Christian; Gochfeld, Michael; Mizrahi, David

2011-01-01

The New Jersey Meadowlands are located within the heavily urbanized New York/New Jersey Harbor Estuary and have been subject to contamination due to effluent and runoff from industry, traffic, and homes along the Hackensack River and nearby waterways. These extensive wetlands, though heavily impacted by development and pollution, support a wide array of bird and other wildlife species. Persistent contaminants may pose threats to birds in these habitats, affecting reproduction, egg hatchability, nestling survival, and neurobehavioral development. Metals of concern in the Meadowlands include arsenic, cadmium, chromium, lead, and mercury. These metals were analyzed in eggs, feathers, muscle, and liver of Canada geese (Branta canadensis) breeding in four wetland sites. We sampled geese collected during control culling (n=26) and collected eggs from goose nests (n=34). Levels of arsenic were below the minimum quantification level (MQL) in most samples, and cadmium and mercury were low in all tissues sampled. Chromium levels were high in feather samples. Mercury levels in eggs of Canada geese, an almost exclusively herbivorous species, were lower (mean ±SE 4.29±0.30 μg/g wet weight) than in eggs of omnivorous mallards (Anas platyrhynchos), and insectivorous red-winged blackbirds (Agelaius phoeniceus) and marsh wrens (Cistothorus palustris) from the Meadowlands, consistent with trophic level differences. However, lead levels were higher in the goose eggs (161±36.7 ng/g) than in the other species. Geese also had higher levels of lead in feathers (1910±386 ng/g) than those seen in Meadowlands passerines. By contrast, muscle and liver lead levels were within the range reported in waterfowl elsewhere, possibly a reflection of metal sequestration in eggs and feathers. Elevated lead levels may be the result of sediment ingestion or ingestion of lead shot and sinkers. Finally, lead levels in goose liver (249±44.7 ng/g) and eggs (161±36.7 ng/g) may pose a risk if consumed

A molecular approach to pre-harvest impact on post-harvest quality of trout

DEFF Research Database (Denmark)

Nielsen, Michael Engelbrecht; Hyldig, Grethe; Nielsen, Henrik Hauch

damage in rainbow trout (Oncorhynchus mykiss). Needle disrupted muscle tissue was sampled at different time points and subject to real-time RT-PCR for measuring the expression of the genes IL-1ß, IL-8, IL-10, TGF-ß, Myostatin-1ab, MMP-2, CTGF, Collagen-1alfa, VEGF, iNOS, Arg-2 and FGF. The results showed...

Status of Oregon's Bull Trout.

Energy Technology Data Exchange (ETDEWEB)

Buchanan, David V.; Hanson, Mary L.; Hooton, Robert M.

1997-10-01

Limited historical references indicate that bull trout Salvelinus confluentus in Oregon were once widely spread throughout at least 12 basins in the Klamath River and Columbia River systems. No bull trout have been observed in Oregon's coastal systems. A total of 69 bull trout populations in 12 basins are currently identified in Oregon. A comparison of the 1991 bull trout status (Ratliff and Howell 1992) to the revised 1996 status found that 7 populations were newly discovered and 1 population showed a positive or upgraded status while 22 populations showed a negative or downgraded status. The general downgrading of 32% of Oregon's bull trout populations appears largely due to increased survey efforts and increased survey accuracy rather than reduced numbers or distribution. However, three populations in the upper Klamath Basin, two in the Walla Walla Basin, and one in the Willamette Basin showed decreases in estimated population abundance or distribution.

Ice processes affect habitat use and movements of adult cutthroat trout and brook trout in a Wyoming foothills stream

Science.gov (United States)

Lindstrom, J.W.; Hubert, W.A.

2004-01-01

Habitat use and movements of 25 adult cutthroat trout Oncorhynchus clarkii and 25 adult brook trout Salvelinus fontinalis from fall through winter 2002-2003 were assessed by means of radiotelemetry in a 7-km reach of a Rocky Mountains foothills stream. Temporal dynamics of winter habitat conditions were evaluated by regularly measuring the features of 30 pools and 5 beaver Castor canadensis ponds in the study reach. Groundwater inputs at three locations raised mean daily water temperatures in the stream channel during winter to 0.2-0.6??C and kept at least 250 m of the downstream channel free of ice, but the lack of surface ice further downstream led to the occurrence of frazil ice and anchor ice in pools and unstable habitat conditions for trout. Pools in segments that were not affected by groundwater inputs and beaver ponds tended to be stable and snow accumulated on the surface ice. Pools throughout the study reach tended to become more stable as snow accumulated. Both cutthroat trout and brook trout selected beaver ponds as winter progressed but tended to use lateral scour pools in proportion to their availability. Tagged fish not in beaver ponds selected lateral scour pools that were deeper than average and stable during winter. Movement frequencies by tagged fish decreased from fall through winter, but some individuals of both species moved during winter. Ice processes affected both the habitat use and movement patterns of cutthroat trout and brook trout in this foothills stream.

Investigations of bull trout (Salvelinus confluentus), steelhead trout (Oncorhynchus mykiss), and spring chinook salmon (O. tshawytscha) interactions in Southeast Washington streams. Final report 1992; FINAL

International Nuclear Information System (INIS)

Underwood, K.D.; Martin, S.W.; Schuck, M.L.; Scholz, A.T.

1995-01-01

The goal of this two year study was to determine if supplementation with hatchery reared steelhead trout (Oncorhynchus mykiss) and spring chinook salmon (O. tshawytscha) negatively impacted wild native bull trout (Salvelinus confluentus) through competitive interactions. Four streams with varying levels of fish supplementation activity were sampled in Southeast Washington. Tasks performed during this study were population density, relative abundance, microhabitat utilization, habitat availability, diet analysis, bull trout spawning ground surveys, radio telemetry of adult bull trout, and growth analysis. Results indicate that bull trout overlapped geographically with the supplemented species in each of the study streams suggesting competition among species was possible. Within a stream, bull trout and the supplemented species utilized dissimilar microhabitats and microhabitat utilization by each species was the same among streams suggesting that there was no shifts in microhabitat utilization among streams. The diet of bull trout and O. mykiss significantly overlapped in each of the study streams. The stream most intensely supplemented contained bull trout with the slowest growth and the non-supplemented stream contained bull trout with the fastest growth. Conversely, the stream most intensely supplemented contain steelhead with the fastest growth and the non-supplemented stream contained steelhead with the slowest growth. Growth indicated that bull trout may have been negatively impacted from supplementation, although other factors may have contributed. At current population levels, and current habitat quantity and quality, no impacts to bull trout as a result of supplementation with hatchery reared steelhead trout and spring chinook salmon were detected. Project limitations and future research recommendations are discussed

YERSINIA RUCKERI INFECT RAINBOW TROUT THROUGH THE GILLS DEMONSTRATED BY A THREE-DIMENSIONAL IMAGING ANALYSIS

DEFF Research Database (Denmark)

Otani, Maki; Raida, Martin Kristian

2013-01-01

-dimensional (3D) imaging of small tissues. Rainbow trout were infected with Yersinia ruckeri O1 biotype 1 (1 x 109 cells/ml) for 1 hour at 18°C, and significant mortality were observed post infection. Three fish were sampled at different time points and fixed in 4% paraformaldehyde for OPT, or 10% formalin...... is a strong tool for 3D visualization of the bacteria infection routes in the host tissues....

Fish mercury levels appear to be increasing lately: a report from 40 years of monitoring in the province of Ontario, Canada.

Science.gov (United States)

Gandhi, Nilima; Tang, Rex W K; Bhavsar, Satyendra P; Arhonditsis, George B

2014-05-20

Recent mercury levels and trends reported for North America suggest a mixed (positive/negative) outlook for the environmental mercury problem. Using one of the largest consistent monitoring data sets in the world, here we present long-term and recent mercury trends in Walleye, Northern Pike, and Lake Trout from the Province of Ontario, Canada, which contains about one-third of the world's fresh water and covers a wide geographical area (1.5 and 3 times larger than France and Germany, respectively). Overall, the results indicate that the fish mercury levels either declined (0.01-0.07 μg/g decade) or remained stable between the 1970s and 2012. The rates of mercury decline were substantially greater (mostly 0.05-0.31 μg/g decade) during the 1970s/80s possibly in response to reductions in mercury emissions. However, Walleye and Pike levels have generally increased (0.01-0.27 μg/g decade) in recent years (1995-2012), especially for northern Ontario (effect sizes for differences between the two periods ranged from 0.39 to 1.04). Proportions of Walleye and Pike locations showing a flat or increasing trend increased from 26-44% to 59-73% between the 1970s/80s and 1995-2012. Mercury emissions in North America have declined over the last few decades, and as such it is logical to expect recovery in fish mercury levels; however, other factors such as global emissions, climate change, invasive species, and local geochemistry are likely affecting the response time and magnitude.

Diurnal stream habitat use of juvenile Atlantic salmon, brown trout and rainbow trout in winter

Science.gov (United States)

Johnson, J. H.; Douglass, K.A.

2009-01-01

The diurnal winter habitat of three species of juvenile salmonids was examined in a tributary of Skaneateles Lake, NY to compare habitat differences among species and to determine if species/age classes were selecting specific habitats. A total of 792 observations were made on the depth, velocity, substrate and cover (amount and type) used by sympatric subyearling Atlantic salmon, subyearling brown trout and subyearling and yearling rainbow trout. Subyearling Atlantic salmon occurred in shallower areas with faster velocities and less cover than the other salmonid groups. Subyearling salmon was also the only group associated with substrate of a size larger than the average size substrate in the study reach during both winters. Subyearling brown trout exhibited a preference for vegetative cover. Compared with available habitat, yearling rainbow trout were the most selective in their habitat use. All salmonid groups were associated with more substrate cover in 2002 under high flow conditions. Differences in the winter habitat use of these salmonid groups have important management implications in terms of both habitat protection and habitat enhancement.

Toxicity of potassium cyanide to trout. [Salmo gairdneri

Energy Technology Data Exchange (ETDEWEB)

Herbert, D W.M.; Merkens, J C

1952-01-01

The toxicity of KCN was tested on 50 rainbow trout using a flow through bioassay system. The system was designed to allow water conditions to remain constant throughout the test rather than change through metabolic activities of the fish. Results show: cyanide causes fish to loose equilibrium; cyanide resistance increases if the trout are allowed to acclimate to test temperatures before cyanides is added; young trout are more resistant to cyanide; and the distribution of trout survival times to cyanide concentration approximates a normal distribution. (14 references, 5 figures, 6 tables.

Spawning and rearing behavior of bull trout in a headwaterlake ecosystem

Science.gov (United States)

Lora B. Tennant,; Gresswell, Bob; Guy, Christopher S.; Michael H. Meeuwig,

2015-01-01

Numerous life histories have been documented for bull trout Salvelinus confluentus. Lacustrine-adfluvial bull trout populations that occupy small, headwater lake ecosystems and migrate short distances to natal tributaries to spawn are likely common; however, much of the research on potamodromous bull trout has focused on describing the spawning and rearing characteristics of bull trout populations that occupy large rivers and lakes and make long distance spawning migrations to natal headwater streams. This study describes the spawning and rearing characteristics of lacustrine-adfluvial bull trout in the Quartz Lake drainage, Glacier National Park, USA, a small headwater lake ecosystem. Many spawning and rearing characteristics of bull trout in the Quartz Lake drainage are similar to potamodromous bull trout that migrate long distances. For example, subadult bull trout distribution was positively associated with slow-water habitat unit types and maximum wetted width, and negatively associated with increased stream gradient. Bull trout spawning also occurred when water temperatures were between 5 and 9 °C, and redds were generally located in stream segments with low stream gradient and abundant gravel and cobble substrates. However, this study also elucidated characteristics of bull trout biology that are not well documented in the literature, but may be relatively widespread and have important implications regarding general characteristics of bull trout ecology, use of available habitat by bull trout, and persistence of lacustrine-adfluvial bull trout in small headwater lake ecosystems.

Maternal transfer of mercury to songbird eggs.

Science.gov (United States)

Ackerman, Joshua T; Hartman, C Alex; Herzog, Mark P

2017-11-01

We evaluated the maternal transfer of mercury to eggs in songbirds, determined whether this relationship differed between songbird species, and developed equations for predicting mercury concentrations in eggs from maternal blood. We sampled blood and feathers from 44 house wren (Troglodytes aedon) and 34 tree swallow (Tachycineta bicolor) mothers and collected their full clutches (n = 476 eggs) within 3 days of clutch completion. Additionally, we sampled blood and feathers from 53 tree swallow mothers and randomly collected one egg from their clutches (n = 53 eggs) during mid to late incubation (6-10 days incubated) to evaluate whether the relationship varied with the timing of sampling the mother's blood. Mercury concentrations in eggs were positively correlated with mercury concentrations in maternal blood sampled at (1) the time of clutch completion for both house wrens (R 2  = 0.97) and tree swallows (R 2  = 0.97) and (2) during mid to late incubation for tree swallows (R 2  = 0.71). The relationship between mercury concentrations in eggs and maternal blood did not differ with the stage of incubation when maternal blood was sampled. Importantly, the proportion of mercury transferred from mothers to their eggs decreased substantially with increasing blood mercury concentrations in tree swallows, but increased slightly with increasing blood mercury concentrations in house wrens. Additionally, the proportion of mercury transferred to eggs at the same maternal blood mercury concentration differed between species. Specifically, tree swallow mothers transferred 17%-107% more mercury to their eggs than house wren mothers over the observed mercury concentrations in maternal blood (0.15-1.92 μg/g ww). In contrast, mercury concentrations in eggs were not correlated with those in maternal feathers and, likewise, mercury concentrations in maternal blood were not correlated with those in feathers (all R 2  mercury concentrations from maternal blood to eggs

Mercury Report-Children's exposure to elemental mercury

Science.gov (United States)

... gov . Mercury Background Mercury Report Additional Resources Mercury Report - Children's Exposure to Elemental Mercury Recommend on Facebook ... I limit exposure to mercury? Why was the report written? Children attending a daycare in New Jersey ...

Selenium and mercury interactions wtih emphasis on fish tissue

Science.gov (United States)

This review addresses the effects of mercury (Hg) in fish as it relates to the health of the fish themselves as well as potential risks of toxicity in wildlife and humans that consume fish. In particular, it addresses selenium (Se) as a bioindicator of susceptibility to harmful e...

Embryotoxicity of quantum dots in rainbow trout Oncorhynchus mykiss during hatching period

Directory of Open Access Journals (Sweden)

Nijolė Kazlauskienė

2015-11-01

Full Text Available Research on quantum dots (QD has become a major interdisciplinary area of science. Unique physic-chemical properties of QD significantly expanded areas of their application and increased the potential impact on hydrosystems. The objectives of complex study (using toxicological, physical, chemical methods were: to determine the toxicity of QD to rainbow trout (Oncorhynchus mykiss during ontogenesis (embryos, larvae depending on the duration of exposure; to estimate QD stability; to investigate QD uptake routes, distribution, accumulation, localization in tissues and different organs of embryos and larvae. This study examined the toxic effects of CdSe/ZnS-COOH at sublethal concentration. Bioassay testing was carried out under controlled laboratory conditions. Short-term (24-, 96-hour and long-term toxicity tests (14-day on fish at early stages of development (starting from “eye-egg” embryos were performed under static conditions. Mortality, physiological parameters, blood circulatory system, development disorders, behavioural responses and growth parameters of larvae were investigated. The results indicated that toxic effects of QD to rainbow trout in early life stages of development depended on the duration of exposure. Long-term exposure of QD induced remarkable deleterious changes in various systems of the developing fish organism: increased mortality, alterations in cardio-respiratory system, disturbed behavioural responses, caused developmental disorders and adversely affected the growth of larvae. Using physical methods it was determined: QD stability, uptake routes, distribution, accumulation and localization in tissues as well as in different organs of embryos and larvae of rainbow trout. Fish toxicity tests results will help to understand ecotoxicity of nanoparticles and will be used as nanoparticle embryotoxicity model in humans and other organisms.

Mercury uptake and accumulation by four species of aquatic plants

International Nuclear Information System (INIS)

Skinner, Kathleen; Wright, Nicole; Porter-Goff, Emily

2007-01-01

The effectiveness of four aquatic plants including water hyacinth (Eichornia crassipes), water lettuce (Pistia stratiotes), zebra rush (Scirpus tabernaemontani) and taro (Colocasia esculenta) were evaluated for their capabilities in removing mercury from water. The plants were exposed to concentrations of 0 mg/L, 0.5 mg/L or 2 mg/L of mercury for 30 days. Assays were conducted using both Microtox[reg] (water) and cold vapor Atomic Absorption Spectroscopy (AAS) (roots and water). The Microtox[reg] results indicated that the mercury induced acute toxicity had been removed from the water. AAS confirmed an increase of mercury within the plant root tissue and a corresponding decrease of mercury in the water. All species of plants appeared to reduce mercury concentrations in the water via root uptake and accumulation. Water lettuce and water hyacinth appeared to be the most effective, followed by taro and zebra rush, respectively. - Four species of aquatic plants reduced mercury in water

Mercury analysis and speciation: The potential role of the IAEA

International Nuclear Information System (INIS)

Horvat, Milena

2001-01-01

Owing to the toxicity of its methylated form, its accumulation in biota and biomagnification in the aquatic food chain, mercury has been at the centre of considerable attention. Inorganic mercury can be methylated by bacterial action and is stored in the muscle tissue of fish. When ingested by man, it can attack the central nervous system. The US Environmental Protection Agency has already set stringent guidelines for the maximum dietary intake of methyl mercury (0.1 μg/kg/day). Up to 10 million people are involved in the use of mercury in gold exploitation which constitutes a significant pollution source in some countries. The biogeochemistry of mercury and the mercury cycle were reviewed. Long range atmospheric transfer mechanisms have led to significant contamination of fish in lakes remote from any pollution source. The value of stable or radioactive isotopic tracers in understanding the mercury cycle was pointed out and the need for relevant natural matrix reference materials for quality control and method development purposes was stressed

Mercury uptake and accumulation by four species of aquatic plants

Energy Technology Data Exchange (ETDEWEB)

Skinner, Kathleen [Department of Biology, Russell Sage College, 45 Ferry Street, Troy, NY 12180 (United States)]. E-mail: skinnk@sage.edu; Wright, Nicole [NEIWPCC-NYSDEC, 625 Broadway, 4th Floor, Albany, NY 12233-3502 (United States)]. E-mail: ndwright@gw.dec.state.ny.us; Porter-Goff, Emily [Department of Biology, Russell Sage College, 45 Ferry Street, Troy, NY 12180 (United States)

2007-01-15

The effectiveness of four aquatic plants including water hyacinth (Eichornia crassipes), water lettuce (Pistia stratiotes), zebra rush (Scirpus tabernaemontani) and taro (Colocasia esculenta) were evaluated for their capabilities in removing mercury from water. The plants were exposed to concentrations of 0 mg/L, 0.5 mg/L or 2 mg/L of mercury for 30 days. Assays were conducted using both Microtox[reg] (water) and cold vapor Atomic Absorption Spectroscopy (AAS) (roots and water). The Microtox[reg] results indicated that the mercury induced acute toxicity had been removed from the water. AAS confirmed an increase of mercury within the plant root tissue and a corresponding decrease of mercury in the water. All species of plants appeared to reduce mercury concentrations in the water via root uptake and accumulation. Water lettuce and water hyacinth appeared to be the most effective, followed by taro and zebra rush, respectively. - Four species of aquatic plants reduced mercury in water.

An immunohistochemical study of Flexibacter psychrophilus infection in experimentally and naturally infected rainbow trout (Oncorhynchus mykiss) fry

DEFF Research Database (Denmark)

Evensen, O.; Lorenzen, Ellen

1996-01-01

An immunohistochemical method is described for the detection of Flexibacter psychrophilus in formalin-fixed, parafiin-wax-embedded fry of rainbow trout. Rabbit antiserum as well as rainbow trout hyperimmune serum were used in the study. The distribution and tissue localization of the bacterium wa...... are typically found during the chronic stage of the disease....... and experimentally infected fry showed that there was a localization of bacteria in the monocyte-macrophage system, in skin lesions, and in the retina and the choroid gland of the eye. The dermal changes included superficial or deep ulcers extending to the subcutaneous tissue or the musculature accompanied...... by inflammatory cell infiltrates in which polymorphonuclear inflammatory cells were shown to contain the bacterium in the cytoplasm by immunostaining. The eye changes were likewise a common finding in chronic cases with severe inflammatory changes in the retina and with numerous bacteria in inflammatory (mainly...

2010 Great Lakes Human Health Fish Tissue Study Fish Tissue Data Dictionary

Science.gov (United States)

The Office of Science and Technology (OST) is providing the fish tissue results from the 2010 Great Lakes Human Health Fish Tissue Study (GLHHFTS). This document includes the “data dictionary” for Mercury, PFC, PBDE and PCBs.

The trout fishery in Shenandoah National Park

Science.gov (United States)

Lennon, Robert E.

1961-01-01

Populations of brook trout in streams of Shenandoah National Park were reduced drastically early in the past decade by a succession of unusually severe droughts and floods. The drying of stream beds, predation, and scouring were principal factors in the loss of fish. The park was closed to fishing in 1954 and 1955 to protect survivors. The small numbers of survivors quickly repopulated the streams after drought conditions abated. The stocking of hatchery-reared fingerling trout in selected waters failed to augment the recovery of populations. Survival and growth of young, wild trout were especially good. Their redistribution through miles of previously dry streams was rapid. The park was opened again to fishing in 1956 under regulations which restrict the take but afford an increase in sporting opportunity. Two streams were placed under fishing-for-fun-only regulations in 1961.The welfare of the trout populations is dependent mostly on the weather cycle . Fish may be abundant in wet years but very scarc e in dry ones. Thus, the stream must be managed a s marginal for trout.

Biology and management of threatened and endangered western trouts

Science.gov (United States)

R. J. Behnke; Mark Zarn

1976-01-01

Discusses taxonomy, reasons for decline, life history and ecology, and suggestions for preservation and management of six closely related trouts native to western North America: Colorado River cutthroat, Salmo clarki pleuriticus; greenback trout, S. c. stomias; Lahontan cutthroat, S. c. henshawi; Paiute trout,...

Novel molecular markers differentiate Oncorhynchus mykiss (rainbow trout and steelhead) and the O. clarki (cutthroat trout) subspecies

Science.gov (United States)

Ostberg, C.O.; Rodriguez, R.J.

2002-01-01

A suite of 26 PCR-based markers was developed that differentiates rainbow (Oncorhynchus mykiss) and coastal cutthroat trout (O. clarki clarki). The markers also differentiated rainbow from other cutthroat trout subspecies (O. clarki), and several of the markers differentiated between cutthroat trout subspecies. This system has numerous positive attributes, including: nonlethal sampling, high species-specificity and products that are easily identified and scored using agarose gel electrophoresis. The methodology described for developing the markers can be applied to virtually any system in which numerous markers are desired for identifying or differentiating species or subspecies.

Monitor and Protect Wigwam River Bull Trout for Koocanusa Reservoir : Summary of the Skookumchuck Creek Bull Trout Enumeration Project, Annual Report 2001.

Energy Technology Data Exchange (ETDEWEB)

Baxter, James S.; Baxter, Jeremy

2002-03-01

This report summarizes the second year of a bull trout (Salvelinus confluentus) enumeration project on Skookumchuck Creek in southeastern British Columbia. An enumeration fence and traps were installed on the creek from September 6th to October 12th 2001 to enable the capture of post-spawning bull trout emigrating out of the watershed. During the study period, a total of 273 bull trout were sampled through the enumeration fence. Length and weight were determined for all bull trout captured. In total, 39 fish of undetermined sex, 61 males and 173 females were processed through the fence. An additional 19 bull trout were observed on a snorkel survey prior to the fence being removed on October 12th. Coupled with the fence count, the total bull trout enumerated during this project was 292 fish. Several other species of fish were captured at the enumeration fence including westslope cutthroat trout (Oncorhynchus clarki lewisi), Rocky Mountain whitefish (Prosopium williamsoni), and kokanee (O. nerka). A total of 143 bull trout redds were enumerated on the ground in two different locations (river km 27.5-30.5, and km 24.0-25.5) on October 3rd. The majority of redds (n=132) were observed in the 3.0 km index section (river km 27.5-30.5) that has been surveyed over the past five years. The additional 11 redds were observed in a 1.5 km section (river km 24.0-25.5). Summary plots of water temperature for Bradford Creek, Sandown Creek, Buhl Creek, and Skookumchuck Creek at three locations suggested that water temperatures were within the temperature range preferred by bull trout for spawning, egg incubation, and rearing.

Exposure to environmental levels of waterborne cadmium impacts corticosteroidogenic and metabolic capacities, and compromises secondary stressor performance in rainbow trout

International Nuclear Information System (INIS)

Sandhu, Navdeep; McGeer, James C.; Vijayan, Mathilakath M.

2014-01-01

Highlights: •Low level chronic waterborne cadmium exposure did not evoke a plasma cortisol response in rainbow trout. •Chronic cadmium exposure increases liver and gill metabolic capacities. •Chronic cadmium exposure disrupts head kidney steroidogenic capacity. •Chronic cadmium exposure disrupts glucocorticoid and mineralocorticoid receptor protein expressions in target tissues. •Chronic cadmium exposure compromises physiological performances to a secondary stressor in trout. -- Abstract: The physiological responses to waterborne cadmium exposure have been well documented; however, few studies have examined animal performances at low exposure concentrations of this metal. We tested the hypothesis that longer-term exposure to low levels of cadmium will compromise the steroidogenic and metabolic capacities, and reduce the cortisol response to a secondary stressor in fish. To test this, juvenile rainbow trout (Oncorhynchus mykiss) were exposed to 0 (control), 0.75 or 2.0 μg/L waterborne cadmium in a flow-through system and were sampled at 1, 7 and 28 d of exposure. There were only very slight disturbances in basal plasma cortisol, lactate or glucose levels in response to cadmium exposure over the 28 d period. Chronic cadmium exposure significantly affected key genes involved in corticosteroidogenesis, including melanocortin 2 receptor, steroidogenic acute regulatory protein and cytochrome P450 side chain cleavage enzyme. At 28 d, the high cadmium exposure group showed a significant drop in the glucocorticoid receptor and mineralocorticoid receptor protein expressions in the liver and brain, respectively. There were also perturbations in the metabolic capacities in the liver and gill of cadmium-exposed trout. Subjecting these fish to a secondary handling disturbance led to a significant attenuation of the stressor-induced plasma cortisol, glucose and lactate levels in the cadmium groups. Collectively, although trout appears to adjust to subchronic exposure

Exposure to environmental levels of waterborne cadmium impacts corticosteroidogenic and metabolic capacities, and compromises secondary stressor performance in rainbow trout

Energy Technology Data Exchange (ETDEWEB)

Sandhu, Navdeep [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); McGeer, James C. [Department of Biology, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5 (Canada); Vijayan, Mathilakath M., E-mail: matt.vijayan@ucalgary.ca [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

2014-01-15

Highlights: •Low level chronic waterborne cadmium exposure did not evoke a plasma cortisol response in rainbow trout. •Chronic cadmium exposure increases liver and gill metabolic capacities. •Chronic cadmium exposure disrupts head kidney steroidogenic capacity. •Chronic cadmium exposure disrupts glucocorticoid and mineralocorticoid receptor protein expressions in target tissues. •Chronic cadmium exposure compromises physiological performances to a secondary stressor in trout. -- Abstract: The physiological responses to waterborne cadmium exposure have been well documented; however, few studies have examined animal performances at low exposure concentrations of this metal. We tested the hypothesis that longer-term exposure to low levels of cadmium will compromise the steroidogenic and metabolic capacities, and reduce the cortisol response to a secondary stressor in fish. To test this, juvenile rainbow trout (Oncorhynchus mykiss) were exposed to 0 (control), 0.75 or 2.0 μg/L waterborne cadmium in a flow-through system and were sampled at 1, 7 and 28 d of exposure. There were only very slight disturbances in basal plasma cortisol, lactate or glucose levels in response to cadmium exposure over the 28 d period. Chronic cadmium exposure significantly affected key genes involved in corticosteroidogenesis, including melanocortin 2 receptor, steroidogenic acute regulatory protein and cytochrome P450 side chain cleavage enzyme. At 28 d, the high cadmium exposure group showed a significant drop in the glucocorticoid receptor and mineralocorticoid receptor protein expressions in the liver and brain, respectively. There were also perturbations in the metabolic capacities in the liver and gill of cadmium-exposed trout. Subjecting these fish to a secondary handling disturbance led to a significant attenuation of the stressor-induced plasma cortisol, glucose and lactate levels in the cadmium groups. Collectively, although trout appears to adjust to subchronic exposure

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.

Overwintering of sea trout (Salmo trutta) in freshwater

DEFF Research Database (Denmark)

Thomsen, Dennis; Koed, Anders; Nielsen, Christian

2007-01-01

Brown trout (Salmo trutta) show large phenotypic plasticity. Juveniles may reside in their native freshwater habitat until maturation or migrate into the ocean as 1- to 3-year-old smolts. Sea-going fish (sea trout) reside at sea for 2-3 years until migrating back to their native stream for reprod......Brown trout (Salmo trutta) show large phenotypic plasticity. Juveniles may reside in their native freshwater habitat until maturation or migrate into the ocean as 1- to 3-year-old smolts. Sea-going fish (sea trout) reside at sea for 2-3 years until migrating back to their native stream...... for reproduction. However, immature fish may leave the ocean during their first or second winter at sea and overwinter in freshwater. The question is why does this occur? We tested the hypothesis that hypo-osmoregulatory capacity is compromised by low temperature in two coastal sea trout populations, one...... representing high salinity and the other, low salinity. Immature sea-run trout were caught in lower parts of two rivers during winter and acclimated to laboratory conditions. Subgroups were challenged with high salinity or low water temperature or both, and their osmoregulatory performance was investigated...

Mercury uptake and accumulation by four species of aquatic plants.

Science.gov (United States)

Skinner, Kathleen; Wright, Nicole; Porter-Goff, Emily

2007-01-01

The effectiveness of four aquatic plants including water hyacinth (Eichornia crassipes), water lettuce (Pistia stratiotes), zebra rush (Scirpus tabernaemontani) and taro (Colocasia esculenta) were evaluated for their capabilities in removing mercury from water. The plants were exposed to concentrations of 0 mg/L, 0.5 mg/L or 2 mg/L of mercury for 30 days. Assays were conducted using both Microtox (water) and cold vapor Atomic Absorption Spectroscopy (AAS) (roots and water). The Microtox results indicated that the mercury induced acute toxicity had been removed from the water. AAS confirmed an increase of mercury within the plant root tissue and a corresponding decrease of mercury in the water. All species of plants appeared to reduce mercury concentrations in the water via root uptake and accumulation. Water lettuce and water hyacinth appeared to be the most effective, followed by taro and zebra rush, respectively.

In vitro infection of salmonid epidermal tissues by infectious hematopoietic necrosis virus and viral hemorrhagic septicemia virus

Science.gov (United States)

Yamamoto, T.; Batts, W.N.; Winton, J.R.

1992-01-01

The ability of two rhabdoviruses, infectious hematopoietic necrosis virus (IHNV) and viral hemorrhagic septicemia virus (VHSV), to infect fish skin was investigated by in vitro infection of excised tissues. Virus replication was determined by plaque assay of homogenized tissue extracts, and the virus antigen was detected by immunohistology of tissue sections. Gill, fin, and ventral abdominal skin tissues of rainbow trout Oncorhynchus mykiss that had been infected in vitro with a virulent strain of IHNV (193–110) produced substantial increases in virus titer within 24 h. Titers continued to increase up until day 3 of incubation; by this time, virus had increased 1,000-fold or more. This increase in IHNV titer occurred in epidermal tissues of fingerlings and of older fish. In another experiment, IHNV replicated in excised rainbow trout tissues whether the fish had been subject to prior infection with a virulent strain of IHNV (Western Regional Aquaculture Consortium isolate) or whether the fish had been infected previously with an attenuated strain of the virus (Nan Scott Lake, with 100 passes in culture). A virulent strain of VHSV (23/75) replicated effectively in excised gill tissues and epidermal tissues of rainbow trout and chinook salmon O. tshawytscha; however, the avirulent North American strain of VHSV (Makah) replicated poorly or not at all.

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.

Estrogenic effects of phytoestrogens in brown trout (Salmo trutta)

DEFF Research Database (Denmark)

Nielsen, Louise Marie; Holbech, Henrik; Bjerregaard, Poul

2010-01-01

, the potential effect of the waterborne phytoestrogens on endemic fish species is largely unknown. In the present investigation, the estrogenic effect of biochanin A was tested in brown trout through water exposure experiments. Juvenile brown trout of both sexes were exposed to different concentrations...... of biochanin A. In a ten day exposure experiments, NOEC and LOEC for plasma vitellogenin induction in brown trout were found to be 0.8µg biochanin A/L and 1.2µg biochanin A/L, respectively. A six hour pulse experiment resulted in NOEC and LOEC for induction of plasma vitellogenin in brown trout of 48µg...... biochanin A/L and 186µg biochanin A/L, respectively. Investigations of the ability of genistein to induce vitellogenin synthesis in brown trout are ongoing....

Metallothionein expression in chloroplasts enhances mercury accumulation and phytoremediation capability.

Science.gov (United States)

Ruiz, Oscar N; Alvarez, Derry; Torres, Cesar; Roman, Laura; Daniell, Henry

2011-06-01

Genetic engineering to enhance mercury phytoremediation has been accomplished by expression of the merAB genes that protects the cell by converting Hg[II] into Hg[0] which volatilizes from the cell. A drawback of this approach is that toxic Hg is released back into the environment. A better phytoremediation strategy would be to accumulate mercury inside plants for subsequent retrieval. We report here the development of a transplastomic approach to express the mouse metallothionein gene (mt1) and accumulate mercury in high concentrations within plant cells. Real-time PCR analysis showed that up to 1284 copies of the mt1 gene were found per cell when compared with 1326 copies of the 16S rrn gene, thereby attaining homoplasmy. Past studies in chloroplast transformation used qualitative Southern blots to evaluate indirectly transgene copy number, whereas we used real-time PCR for the first time to establish homoplasmy and estimate transgene copy number and transcript levels. The mt1 transcript levels were very high with 183,000 copies per ng of RNA or 41% the abundance of the 16S rrn transcripts. The transplastomic lines were resistant up to 20 μm mercury and maintained high chlorophyll content and biomass. Although the transgenic plants accumulated high concentrations of mercury in all tissues, leaves accumulated up to 106 ng, indicating active phytoremediation and translocation of mercury. Such accumulation of mercury in plant tissues facilitates proper disposal or recycling. This study reports, for the first time, the use of metallothioneins in plants for mercury phytoremediation. Chloroplast genetic engineering approach is useful to express metal-scavenging proteins for phytoremediation. © 2011 The Authors. Plant Biotechnology Journal © 2011 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

Cadmium-mediated disruption of cortisol biosynthesis involves suppression of corticosteroidogenic genes in rainbow trout

International Nuclear Information System (INIS)

Sandhu, Navdeep; Vijayan, Mathilakath M.

2011-01-01

Cadmium is widely distributed in the aquatic environment and is toxic to fish even at sublethal concentrations. This metal is an endocrine disruptor, and one well established role in teleosts is the suppression of adrenocorticotrophic hormone (ACTH)-stimulated cortisol biosynthesis by the interrenal tissue. However the mechanism(s) leading to this steroid suppression is poorly understood. We tested the hypothesis that cadmium targets genes encoding proteins critical for corticosteroid biosynthesis, including melanocortin 2 receptor (MC2R), steroidogenic acute regulatory protein (StAR) and cytochrome P450 side chain cleavage enzyme (P450scc), in rainbow trout (Oncorhynchus mykiss). To test this, head kidney slices (containing the interrenal tissues) were incubated in vitro with cadmium chloride (0, 10, 100 and 1000 nM) for 4 h either in the presence or absence of ACTH (0.5 IU/mL). In the unstimulated head kidney slices, cadmium exposure did not affect basal cortisol secretion and the mRNA levels of MC2R and P450scc, while StAR gene expression was significantly reduced. Cadmium exposure significantly suppressed ACTH-stimulated cortisol production in a dose-related fashion. This cadmium-mediated suppression in corticosteroidogenesis corresponded with a significant reduction in MC2R, StAR and P450scc mRNA levels in trout head kidney slices. The inhibition of ACTH-stimulated cortisol production and suppression of genes involved in corticosteroidogenesis by cadmium were completely abolished in the presence of 8-Bromo-cAMP (a cAMP analog). Overall, cadmium disrupts the expression of genes critical for corticosteroid biosynthesis in rainbow trout head kidney slices. However, the rescue of cortisol production as well as StAR and P450scc gene expressions by cAMP analog suggests that cadmium impact occurs upstream of cAMP production. We propose that MC2R signaling, the primary step in ACTH-induced cortocosteroidogenesis, is a key target for cadmium-mediated disruption of

Cadmium-mediated disruption of cortisol biosynthesis involves suppression of corticosteroidogenic genes in rainbow trout

Energy Technology Data Exchange (ETDEWEB)

Sandhu, Navdeep [Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada); Vijayan, Mathilakath M., E-mail: mvijayan@uwaterloo.ca [Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada)

2011-05-15

Cadmium is widely distributed in the aquatic environment and is toxic to fish even at sublethal concentrations. This metal is an endocrine disruptor, and one well established role in teleosts is the suppression of adrenocorticotrophic hormone (ACTH)-stimulated cortisol biosynthesis by the interrenal tissue. However the mechanism(s) leading to this steroid suppression is poorly understood. We tested the hypothesis that cadmium targets genes encoding proteins critical for corticosteroid biosynthesis, including melanocortin 2 receptor (MC2R), steroidogenic acute regulatory protein (StAR) and cytochrome P450 side chain cleavage enzyme (P450scc), in rainbow trout (Oncorhynchus mykiss). To test this, head kidney slices (containing the interrenal tissues) were incubated in vitro with cadmium chloride (0, 10, 100 and 1000 nM) for 4 h either in the presence or absence of ACTH (0.5 IU/mL). In the unstimulated head kidney slices, cadmium exposure did not affect basal cortisol secretion and the mRNA levels of MC2R and P450scc, while StAR gene expression was significantly reduced. Cadmium exposure significantly suppressed ACTH-stimulated cortisol production in a dose-related fashion. This cadmium-mediated suppression in corticosteroidogenesis corresponded with a significant reduction in MC2R, StAR and P450scc mRNA levels in trout head kidney slices. The inhibition of ACTH-stimulated cortisol production and suppression of genes involved in corticosteroidogenesis by cadmium were completely abolished in the presence of 8-Bromo-cAMP (a cAMP analog). Overall, cadmium disrupts the expression of genes critical for corticosteroid biosynthesis in rainbow trout head kidney slices. However, the rescue of cortisol production as well as StAR and P450scc gene expressions by cAMP analog suggests that cadmium impact occurs upstream of cAMP production. We propose that MC2R signaling, the primary step in ACTH-induced cortocosteroidogenesis, is a key target for cadmium-mediated disruption of

Impact of thiamine deficiency on T-cell dependent and T-cell independent antibody production in lake trout

Science.gov (United States)

Ottinger, Christopher A.; Honeyfield, Dale C.; Densmore, Christine L.; Iwanowicz, Luke R.

2012-01-01

Lake trout Salvelinus namaycush on thiamine-replete and thiamine-depleted diets were evaluated for the effects of thiamine status on in vivo responses to the T-dependent antigen trinitophenol (TNP)-keyhole limpet hemocyanin (TNP-KLH), the T-independent antigen trinitrophenol-lipolysaccaharide (TNP-LPS), or Dulbecco's phosphate-buffered saline (DPBS; negative control fish). Plasma antibody concentrations were evaluated for possible differences in total anti-TNP activity as well as differences in response kinetics. Associations between anti-TNP activity and muscle and liver thiamine concentrations as well as ratios of muscle-to-liver thiamine to anti-TNP activity were also examined. Thiamine-depleted lake trout that were injected with TNP-LPS exhibited significantly more anti-TNP activity than thiamine-replete fish. The depleted fish injected with TNP-LPS also exhibited significantly different response kinetics relative to thiamine-replete lake trout. No differences in activity or kinetics were observed between the thiamine-replete and -depleted fish injected with TNP-KLH or in the DPBS negative controls. Anti-TNP activity in thiamine-depleted lake trout injected with TNP-KLH was positively associated with muscle thiamine pyrophosphate (thiamine diphosphate; TPP) concentration. A negative association was observed between the ratio of muscle-to-liver TPP and T-independent responses. No significant associations between anti-TNP activity and tissue thiamine concentration were observed in the thiamine-replete fish. We demonstrated that thiamine deficiency leads to alterations in both T-dependent and T-independent immune responses in lake trout.

Impact of thiamine deficiency on T-cell dependent and T-cell independent antibody production in lake trout.

Science.gov (United States)

Ottinger, Christopher A; Honeyfield, Dale C; Densmore, Christine L; Iwanowicz, Luke R

2012-12-01

Lake trout Salvelinus namaycush on thiamine-replete and thiamine-depleted diets were evaluated for the effects of thiamine status on in vivo responses to the T-dependent antigen trinitophenol (TNP)-keyhole limpet hemocyanin (TNP-KLH), the T-independent antigen trinitrophenol-lipolysaccaharide (TNP-LPS), or Dulbecco's phosphate-buffered saline (DPBS; negative control fish). Plasma antibody concentrations were evaluated for possible differences in total anti-TNP activity as well as differences in response kinetics. Associations between anti-TNP activity and muscle and liver thiamine concentrations as well as ratios of muscle-to-liver thiamine to anti-TNP activity were also examined. Thiamine-depleted lake trout that were injected with TNP-LPS exhibited significantly more anti-TNP activity than thiamine-replete fish. The depleted fish injected with TNP-LPS also exhibited significantly different response kinetics relative to thiamine-replete lake trout. No differences in activity or kinetics were observed between the thiamine-replete and -depleted fish injected with TNP-KLH or in the DPBS negative controls. Anti-TNP activity in thiamine-depleted lake trout injected with TNP-KLH was positively associated with muscle thiamine pyrophosphate (thiamine diphosphate; TPP) concentration. A negative association was observed between the ratio of muscle-to-liver TPP and T-independent responses. No significant associations between anti-TNP activity and tissue thiamine concentration were observed in the thiamine-replete fish. We demonstrated that thiamine deficiency leads to alterations in both T-dependent and T-independent immune responses in lake trout.

Hippocampal Dysfunction Provoked by Mercury Chloride Exposure: Evaluation of Cognitive Impairment, Oxidative Stress, Tissue Injury and Nature of Cell Death

Directory of Open Access Journals (Sweden)

Walessa Alana Bragança Aragão

2018-01-01

Full Text Available Mercury (Hg is a highly toxic metal, which can be found in its inorganic form in the environment. This form presents lower liposolubility and lower absorption in the body. In order to elucidate the possible toxicity of inorganic Hg in the hippocampus, we investigated the potential of low doses of mercury chloride (HgCl2 to promote hippocampal dysfunction by employing a chronic exposure model. For this, 56 rats were exposed to HgCl2 (0.375 mg/kg/day via the oral route for 45 days. After the exposure period, the animals were submitted to the cognitive test of fear memory. The hippocampus was collected for the measurement of total Hg levels, analysis of oxidative stress, and evaluation of cytotoxicity, apoptosis, and tissue injury. It was observed that chronic exposure to inorganic Hg promotes an increase in mercury levels in this region and damage to short- and long-term memory. Furthermore, we found that this exposure model provoked oxidative stress, which led to cytotoxicity and cell death by apoptosis, affecting astrocytes and neurons in the hippocampus. Our study demonstrated that inorganic Hg, even with its low liposolubility, is able to produce deleterious effects in the central nervous system, resulting in cognitive impairment and hippocampal damage when administered for a long time at low doses in rats.

Trout in the Classroom

Science.gov (United States)

Heath, Thomas

2014-05-01

Trout in the Classroom (TIC) is a conservation-oriented environmental education program for elementary, middle, and high school students. During the year each teacher tailors the program to fit his or her curricular needs. Therefore, each TIC program is unique. TIC has interdisciplinary applications in science, social studies, mathematics, language arts, fine arts, and physical education. In the program, students and teachers raise trout from fertilized eggs supplied by Virginia Department of Game and Inland Fisheries (VGIF) hatcheries, in aquariums equipped with special chillers designed to keep the water near 50 degrees F. The students make daily temperature measurements, and monitor pH, dissolved oxygen, conductivity, and ammonia levels. They record their data, plot trends, and make sure that the water quality is sufficient to support trout development. The fingerlings, which hatch in late October, are almost an inch and a half long by mid-January. And towards the end of the school year, students will release the fry into VGIF approved watersheds. TIC programs have been in place all across the country for more than 20 years, and are the result of numerous collaborations between teachers, volunteers, government agencies, and local organizations like Trout Unlimited. The programs were designed specifically for teachers who wanted to incorporate more environmental education into their curriculum. While the immediate goal of Trout in the Classroom is to increase student knowledge of water quality and cold water conservation, its long-term goal is to reconnect an increasingly urbanized population of youth to the system of streams, rivers, and watersheds that sustain them. Successful programs have helped: connect students to their local environments and their local watersheds; teach about watershed health and water quality, and; get students to care about fish and the environment. In Virginia, the TIC program is now in its 8th year. Over the past year, the program

Three-dimensional imaging analysis of Yersinia ruckeri infected rainbow trout (Oncorhynchus mykiss) gills by optical projection tomography

DEFF Research Database (Denmark)

Otani, Maki; Raida, Martin Kristian

Optical projection tomography (OPT) is a new tool for three-dimensional (3D) imaging of small tissues or embryos, based on multi-angle recording of internal fluorescent signals using intact whole mount tissue or fish. To understand the route of infection, gills of Y. ruckeri infected rainbow trout...... were labeled with fluorescent antibody and visualized in 3D by the OPT scanner. Rainbow trout were infected with Y. ruckeri O1 biotype 1 (1 x 109 cells/ml) for 1 hour at 18 °C, and then transferred to clean water. Three fish were sampled at 12 different time points and fixed in 4% PFA. The gills were...... incubated whole with rabbit anti-Y. ruckeri polyclonal antibody and Alexa Fluor®594 conjugated goat anti-rabbit IgG. After embedding in 1% low melting point agarose, specimens were dehydrated in 100% methanol and cleared in BABB (benzyl alcohol: benzyl benzoate) for OPT scanning. 3D imaging results showed...

Outbreak of viral haemorrhagic septicaemic (VHS) in seawater-farmed rainbow trout in Norway caused by VHS virus genotype III

DEFF Research Database (Denmark)

Dale, Ole Bendik; Ørpetveit, Irene; Lyngstad, Trude Marie

2009-01-01

with slightly elevated mortality was confirmed at a seawater site rearing rainbow trout (90 to 440 g). Within 3 to 4 mo, the disease was recognised in 3 neighbouring sea sites with on-growing rainbow trout. The clinical, gross pathological and histopathological findings were in accordance with VHS......, and the diagnosis was confirmed by the detection of VHSV in brain and internal tissues by immunohistochemistry, cell culture and reverse transcriptase PCR (RT-PCR). Sequence analysis of the G-gene revealed that the isolated virus clustered with VHSV Genotype III and that the Norwegian isolate represents a unique...

Mercury

Science.gov (United States)

Mercury is an element that is found in air, water and soil. It has several forms. Metallic mercury is a shiny, silver-white, odorless liquid. If ... with other elements to form powders or crystals. Mercury is in many products. Metallic mercury is used ...

Mercury in terrestrial forested systems with highly elevated mercury deposition in southwestern China: The risk to insects and potential release from wildfires

International Nuclear Information System (INIS)

Zhou, Jun; Wang, Zhangwei; Sun, Ting; Zhang, Huan; Zhang, Xiaoshan

2016-01-01

Forests are considered a pool of mercury in the global mercury cycle. However, few studies have investigated the distribution of mercury in the forested systems in China. Tieshanping forest catchment in southwest China was impacted by mercury emissions from industrial activities and coal combustions. Our work studied mercury content in atmosphere, soil, vegetation and insect with a view to estimating the potential for mercury release during forest fires. Results of the present study showed that total gaseous mercury (TGM) was highly elevated and the annual mean concentration was 3.51 ± 1.39 ng m"−"2. Of the vegetation tissues, the mercury concentration follows the order of leaf/needle > root > bark > branch > bole wood for each species. Total ecosystem mercury pool was 103.5 mg m"−"2 and about 99.4% of the mercury resides in soil layers (0–40 cm). The remaining 0.6% (0.50 mg m"−"2) of mercury was stored in biomass. The large mercury stocks in the forest ecosystem pose a serious threat for large pluses to the atmospheric mercury during potential wildfires and additional ecological stress to forest insect: dung beetles, cicada and longicorn, with mercury concentration of 1983 ± 446, 49 ± 38 and 7 ± 5 ng g"−"1, respectively. Hence, the results obtained in the present study has implications for global estimates of mercury storage in forests, risks to forest insect and potential release to the atmosphere during wildfires. - Highlights: • Mercury in air, soil, biomass and insect were studied at a subtropical forest. • 99.4% of the total ecosystem mercury pools was resided in soil layers. • High mercury pools were large pulses to the atmosphere during potential wildfires. • High mercury deposition in forest pose an ecological stress to insect. - Large mercury pools in forest pose a serious threat for large pluses to the atmospheric mercury during potential wildfires and ecological stress to insect.

Effects of iron chloride/zeolıte on G6PD of rainbow trout (Oncorhynchus mykiss)'s liver tissue

Science.gov (United States)

Alak, Gonca; Uçar, Arzu; Parlak, Veysel; Kocaman, Esat Mahmut; Atamanalp, Muhammed

2016-04-01

Aquatic ecosystems have been negatively affected by the contamination of ground and surface waters as a result of various activities. Due to the ferrous chloride (FeCl2), which is used as the reducing agent for the organic synthesis reactions in the contamination of water column and sediment, iron salts may be very toxic for some aquatic organisms. In order to minimize these effects, natural products such as zeolite have been widely used in recently years. For this reason, rainbow trout were exposed to FeCl2 and/or zeolite ((FeCl2 (0.002 mg/l)(A), FeCl2+zeolite (0.002 mg/l+1 gr/l) (B), zeolite (1 gr/l) (C) and control (without FeCl2 and/or zeolite (D)). for 28 days and their oxidative stress responses were investigated. At the end of the treatment period, Glucose-6- phosphate dehydrogenase (G6PD) activity was determined in the samples taken from livers. G6PD values for liver tissues were found statistically important in the control and treatment groups (p<0.01).

Bull Trout Population Assessment in the Columbia River Gorge : Annual Report 2000.

Energy Technology Data Exchange (ETDEWEB)

Byrne, Jim; McPeak, Ron

2001-02-01

We summarized existing knowledge regarding the known distribution of bull trout (Salvelinus confluentus) across four sub-basins in the Columbia River Gorge in Washington. The Wind River, Little White Salmon River, White Salmon River, and the Klickitat River sub-basins were analyzed. Cold water is essential to the survival, spawning, and rearing of bull trout. We analyzed existing temperature data, installed Onset temperature loggers in the areas of the four sub-basins where data was not available, and determined that mean daily water temperatures were <15 C and appropriate for spawning and rearing of bull trout. We snorkel surveyed more than 74 km (46.25 mi.) of rivers and streams in the four sub-basins (13.8 km at night and 60.2 km during the day) and found that night snorkeling was superior to day snorkeling for locating bull trout. Surveys incorporated the Draft Interim Protocol for Determining Bull Trout Presence (Peterson et al. In Press). However, due to access and safety issues, we were unable to randomly select sample sites nor use block nets as recommended. Additionally, we also implemented the Bull Trout/Dolly Varden sampling methodology described in Bonar et al. (1997). No bull trout were found in the Wind River, Little White Salmon, or White Salmon River sub-basins. We found bull trout in the West Fork Klickitat drainage of the Klickitat River Sub-basin. Bull trout averaged 6.7 fish/100m{sup 2} in Trappers Creek, 2.6 fish/100m{sup 2} on Clearwater Creek, and 0.4 fish/100m{sup 2} in Little Muddy Creek. Bull trout was the only species of salmonid encountered in Trappers Creek and dominated in Clearwater Creek. Little Muddy Creek was the only creek where bull trout and introduced brook trout occurred together. We found bull trout only at night and typically in low flow regimes. A single fish, believed to be a bull trout x brook trout hybrid, was observed in the Little Muddy Creek. Additional surveys are needed in the West Fork Klickitat and mainstem

Mink predation on brown trout in a Black Hills stream

Science.gov (United States)

Davis, Jacob L.; Wilhite, Jerry W.; Chipps, Steven R.

2016-01-01

In the early 2000’s, declines in the brown trout (Salmo trutta) fishery in Rapid Creek, South Dakota, caused concern for anglers and fisheries managers. We conducted a radio telemetry study in 2010 and 2011 to identify predation mortality associated with mink, using hatchery-reared (2010) or wild (2011) brown trout. Estimated predation rates by mink (Mustela vison) on radio-tagged brown trout were 30% for hatchery fish and 32% for wild fish. Size frequency analysis revealed that the size distribution of brown trout lost to predation was similar to that of other, radio-tagged brown trout. In both years, a higher proportion of predation mortality (83–92%) occurred during spring, consistent with seasonal fish consumption by mink. Predation by mink appeared to be a significant source of brown trout mortality in our study.

Mercury concentrations in cattle from NW Spain.

Science.gov (United States)

López Alonso, M; Benedito, J L; Miranda, M; Castillo, C; Hernández, J; Shore, R F

2003-01-20

Mercury is a toxic metal that is released into the environment as a result of various industrial and agricultural processes. It can be accumulated by domestic animals and so contaminate human foodstuffs. To date, there is no information on mercury residues in livestock in Spain and the aim of the present study was to quantify the concentrations of mercury in cattle in two of the major regions in north-west Spain, Galicia (a largely rural region) and Asturias, which is characterised by heavy industry and mining. Total mercury concentrations were determined in tissue (liver, kidney and muscle) and blood from 284 calves (6-10 months old) and 56 cows (2-16 years old) from across the whole of the two regions. Mercury was usually detected in the kidney (62.4-87.5% of samples) but most (79.5-96%) liver, muscle and blood samples did not contain detectable residues. Renal mercury concentrations did not differ between male and female calves but were significantly greater in female calves than in cows. Unexpectedly, kidney mercury concentrations were significantly higher in calves from the predominantly rural region of Galicia (geometric mean: 12.2 microg/kg w.wt.) than in animals from the industrialised-mining region of Asturias (3.40 microg/kg w.wt.). Overall, mercury residues in cattle from NW Spain were similar to those reported in cattle from non-polluted areas in other countries and do not constitute a risk to animal or human health. Copyright 2002 Elsevier Science B.V.

Identification, characterization and genetic mapping of TLR7, TLR8a1 and TLR8a2 genes in rainbow trout (Oncorhynchus mykiss)

Science.gov (United States)

Palti, Yniv; Gahr, Scott A.; Purcell, Maureen K.; Hadidi, Sima; Rexroad, Caird E.; Wiens, Gregory A.

2010-01-01

Induction of the innate immune pathways is critical for early anti-viral defense but there is limited understanding of how teleost fish recognize viral molecules and activate these pathways. In mammals, Toll-like receptors (TLR) 7 and 8 bind single-stranded RNA of viral origin and are activated by synthetic anti-viral imidazoquinoline compounds. Herein, we identify and describe the rainbow trout (Oncorhynchus mykiss) TLR7 and TLR8 gene orthologs and their mRNA expression. Two TLR7/8 loci were identified from a rainbow trout bacterial artificial chromosome (BAC) library using DNA fingerprinting and genetic linkage analyses. Direct sequencing of two representative BACs revealed intact omTLR7 and omTLR8a1 open reading frames (ORFs) located on chromosome 3 and a second locus on chromosome 22 that contains an omTLR8a2 ORF and a putative TLR7 pseudogene. We used the omTLR8a1/2 nomenclature for the two trout TLR8 genes as phylogenetic analysis revealed that they and all the other teleost TLR8 genes sequenced to date are similar to the zebrafish TLR8a, but are distinct from the zebrafish TLR8b. The duplicated trout loci exhibit conserved synteny with other fish genomes extending beyond the tandem of TLR7/8 genes. The trout TLR7 and 8a1/2 genes are composed of a single large exon similar to all other described TLR7/8 genes. The omTLR7 ORF is predicted to encode a 1049 amino acid (aa) protein with 84% similarity to the Fugu TLR7 and a conserved pattern of predicted leucine-rich repeats (LRR). The omTLR8a1 and omTLR8a2 are predicted to encode 1035- and 1034-aa proteins, respectively, and have 86% similarity to each other. omTLR8a1 is likely the ortholog of the only Atlantic salmon TLR8 gene described to date as they have 95% aa sequence similarity. The tissue expression profiles of omTLR7, omTLR8a1 and omTLR8a2 in healthy trout were highest in spleen tissue followed by anterior and then posterior kidney tissues. Rainbow trout anterior kidney leukocytes produced elevated

Bioaccumulation and subcellular partitioning of zinc in rainbow trout (Oncorhynchus mykiss): Cross-talk between waterborne and dietary uptake

International Nuclear Information System (INIS)

Sappal, Ravinder; Burka, John; Dawson, Susan; Kamunde, Collins

2009-01-01

Zinc homeostasis was studied at the tissue and gill subcellular levels in rainbow trout (Oncorhynchus mykiss) following waterborne and dietary exposures, singly and in combination. Juvenile rainbow trout were exposed to 150 or 600 μg l -1 waterborne Zn, 1500 or 4500 μg g -1 dietary Zn, and a combination of 150 μg l -1 waterborne and 1500 μg g -1 dietary Zn for 40 days. Accumulation of Zn in tissues and gill subcellular fractions was measured. At the tissue level, the carcass acted as the main Zn depot containing 84-90% of whole body Zn burden whereas the gill held 4-6%. At the subcellular level, the majority of gill Zn was bioavailable with the estimated metabolically active pool being 81-90%. Interestingly, the nuclei-cellular debris fraction bound the highest amount (40%) of the gill Zn burden. There was low partitioning of Zn into the detoxified pool (10-19%) suggesting that sequestration and chelation are not major mechanisms of cellular Zn homeostasis in rainbow trout. Further, the subcellular partitioning of Zn did not conform to the spill-over model of metal toxicity because Zn binding was indiscriminate irrespective of exposure concentration and duration. The contribution of the branchial and gastrointestinal uptake pathways to Zn accumulation depended on the tissue. Specifically, in plasma, blood cells, and gill, uptake from water was dominant whereas both pathways appeared to contribute equally to Zn accumulation in the carcass. Subcellularly, additive uptake from the two pathways was observed in the heat-stable proteins (HSP) fraction. Toxicologically, Zn exposure caused minimal adverse effects manifested by a transitory inhibition of protein synthesis in gills in the waterborne exposure. Overall, subcellular fractionation appears to have value in the quest for a better understanding of Zn homeostasis and interactions between branchial and gastrointestinal uptake pathways

Bioaccumulation and subcellular partitioning of zinc in rainbow trout (Oncorhynchus mykiss): Cross-talk between waterborne and dietary uptake

Energy Technology Data Exchange (ETDEWEB)

Sappal, Ravinder; Burka, John; Dawson, Susan [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE C1A 4P3 (Canada); Kamunde, Collins [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE C1A 4P3 (Canada)], E-mail: ckamunde@upei.ca

2009-03-09

Zinc homeostasis was studied at the tissue and gill subcellular levels in rainbow trout (Oncorhynchus mykiss) following waterborne and dietary exposures, singly and in combination. Juvenile rainbow trout were exposed to 150 or 600 {mu}g l{sup -1} waterborne Zn, 1500 or 4500 {mu}g g{sup -1} dietary Zn, and a combination of 150 {mu}g l{sup -1} waterborne and 1500 {mu}g g{sup -1} dietary Zn for 40 days. Accumulation of Zn in tissues and gill subcellular fractions was measured. At the tissue level, the carcass acted as the main Zn depot containing 84-90% of whole body Zn burden whereas the gill held 4-6%. At the subcellular level, the majority of gill Zn was bioavailable with the estimated metabolically active pool being 81-90%. Interestingly, the nuclei-cellular debris fraction bound the highest amount (40%) of the gill Zn burden. There was low partitioning of Zn into the detoxified pool (10-19%) suggesting that sequestration and chelation are not major mechanisms of cellular Zn homeostasis in rainbow trout. Further, the subcellular partitioning of Zn did not conform to the spill-over model of metal toxicity because Zn binding was indiscriminate irrespective of exposure concentration and duration. The contribution of the branchial and gastrointestinal uptake pathways to Zn accumulation depended on the tissue. Specifically, in plasma, blood cells, and gill, uptake from water was dominant whereas both pathways appeared to contribute equally to Zn accumulation in the carcass. Subcellularly, additive uptake from the two pathways was observed in the heat-stable proteins (HSP) fraction. Toxicologically, Zn exposure caused minimal adverse effects manifested by a transitory inhibition of protein synthesis in gills in the waterborne exposure. Overall, subcellular fractionation appears to have value in the quest for a better understanding of Zn homeostasis and interactions between branchial and gastrointestinal uptake pathways.

Sensitivity of Trout to Chronic Acute Exposure to Selenium

DEFF Research Database (Denmark)

Nielsen, Gunnar Gissel; Nielsen, M. Gissel

1978-01-01

Trout were exposed to selenite (Na2SeO3) solutions of varying concentrations (0.1-100 ppm Se) for periods of up to 4 wk. A chronic exposure to 0.1 ppm Se or less is non-lethal to trout. Lethality at higher concentrations depends on the length of exposure. Trout that survive for 10 days in tap...

Attenuation of the cortisol response to stress in female rainbow trout chronically exposed to dietary selenomethionine

International Nuclear Information System (INIS)

Wiseman, Steve; Thomas, Jith K.; McPhee, Landon; Hursky, Olesya; Raine, Jason C.; Pietrock, Michael; Giesy, John P.; Hecker, Markus; Janz, David M.

2011-01-01

, abundances of transcripts of cytochrome P450 side-chain cleavage (p450scc) and cytochrome P450 11B1 (cyp11b1) were not significantly different between controls and Se-Met exposed trout. Exposure to Se-Met affected accumulation and tissue partitioning of glycogen and triglycerides in liver and muscle as concentrations of these energy reserves were greater in muscle, but not liver. Concentrations of glycogen and triglycerides in muscle, but not in liver, were lesser following the handling stressor suggesting that the muscle energy reserves are an important source of energy required for recovery from the handling stressor. The results of the study demonstrate that chronic exposure to dietary Se-Met elicits a stress response, but prevents a cortisol response to a secondary handling stressor, most likely due to cortisol inactivation. Moreover, exposure to Se-Met has effects on concentrations of energy reserves that are important for providing the energy necessary to cope with a secondary stressor.

Attenuation of the cortisol response to stress in female rainbow trout chronically exposed to dietary selenomethionine

Energy Technology Data Exchange (ETDEWEB)

Wiseman, Steve, E-mail: steve.wiseman@usask.ca [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, S7N 5B3 (Canada); Thomas, Jith K.; McPhee, Landon; Hursky, Olesya; Raine, Jason C. [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, S7N 5B3 (Canada); Pietrock, Michael [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, S7N 5B3 (Canada); Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK, S7N 5B3 (Canada); Giesy, John P. [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, S7N 5B3 (Canada); Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK, S7N 5B3 (Canada); Department of Zoology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong (Hong Kong); School of Biological Sciences, University of Hong Kong, Hong Kong (Hong Kong); Department of Zoology, Center for Integrative Toxicology, Michigan State University, East Lansing, MI 48824 (United States); State Key Laboratory of Pollution Control and Resource Reuse and School of the Environment, Nanjing University, Nanjing (China); Hecker, Markus [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, S7N 5B3 (Canada); School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK, S7N 5CB (Canada); Janz, David M. [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, S7N 5B3 (Canada); Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK, S7N 5B3 (Canada)

2011-10-15

, abundances of transcripts of cytochrome P450 side-chain cleavage (p450scc) and cytochrome P450 11B1 (cyp11b1) were not significantly different between controls and Se-Met exposed trout. Exposure to Se-Met affected accumulation and tissue partitioning of glycogen and triglycerides in liver and muscle as concentrations of these energy reserves were greater in muscle, but not liver. Concentrations of glycogen and triglycerides in muscle, but not in liver, were lesser following the handling stressor suggesting that the muscle energy reserves are an important source of energy required for recovery from the handling stressor. The results of the study demonstrate that chronic exposure to dietary Se-Met elicits a stress response, but prevents a cortisol response to a secondary handling stressor, most likely due to cortisol inactivation. Moreover, exposure to Se-Met has effects on concentrations of energy reserves that are important for providing the energy necessary to cope with a secondary stressor.

Fish consumption limit for mercury compounds

Directory of Open Access Journals (Sweden)

Abbas Esmaili-Sari

2011-09-01

Full Text Available Background and objectives: Methyl mercury can carry out harmful effects on the reproductive, respiratory, and nervous system of human. Moreover, mercury is known as the most toxic heavy metal in nature. Fish and seafood consumption is the major MeHg exposure route for human. The present study tries to cover researches which have been conducted on mercury levels in 21 species of fish from Persian Gulf, Caspian Sea and Anzali Wetland during the past 6 years, and in addition to stating mercury level, it provides recommendations about the restriction of monthly fish consumption for each species separately. Material and methods: Fish samples were transferred to the laboratory and stored in refrigerator under -20oC until they were dissected. Afterwards, the muscle tissues were separated and dried. The dried samples were ground and changed into a homogenous powder and then the mercury concentration rate has been determined by advanced mercury analyzer, model 254. Results: In general, mercury contamination in fishes caught from Anzali Wetland was much more than fishes from Caspian Sea. Also, from among all studied fishes, oriental sole (Euryglossa orientalis, caught from Persian Gulf, allocated the most mercury level to itself with the rate of 5.61ml per kg., therefore, it exercises a severe consumption restriction for pregnant women and vulnerable groups. Conclusion: Based on the calculations, about 50% of fishes, mostly with short food chain, can be easily consumed during the year. However, with regard to Oriental sole (Euryglossa orientalis and shark (Carcharhinus dussumieri, caught from Persian Gulf, special consideration should be taken in their consumption. On the other hand, careful planning should be made for the high rate of fish consumption among fishing community.

Evaluation of dietary soy sensitivity in snake river cutthroat trout

Science.gov (United States)

Hatchery-cultured cutthroat trout fed some commercially available rainbow trout feeds display slow growth and increased mortality. Feed characteristics such as buoyancy and texture alter feed acceptance in some fish species but their effects have not been adequately addressed in cutthroat trout. Th...

Got Mercury?

Science.gov (United States)

Meyers, Valerie E.; McCoy, J. Torin; Garcia, Hector D.; James, John T.

2009-01-01

Many of the operational and payload lighting units used in various spacecraft contain elemental mercury. If these devices were damaged on-orbit, elemental mercury could be released into the cabin. Although there are plans to replace operational units with alternate light sources, such as LEDs, that do not contain mercury, mercury-containing lamps efficiently produce high quality illumination and may never be completely replaced on orbit. Therefore, exposure to elemental mercury during spaceflight will remain possible and represents a toxicological hazard. Elemental mercury is a liquid metal that vaporizes slowly at room temperature. However, it may be completely vaporized at the elevated operating temperatures of lamps. Although liquid mercury is not readily absorbed through the skin or digestive tract, mercury vapors are efficiently absorbed through the respiratory tract. Therefore, the amount of mercury in the vapor form must be estimated. For mercury releases from lamps that are not being operated, we utilized a study conducted by the New Jersey Department of Environmental Quality to calculate the amount of mercury vapor expected to form over a 2-week period. For longer missions and for mercury releases occurring when lamps are operating, we conservatively assumed complete volatilization of the available mercury. Because current spacecraft environmental control systems are unable to remove mercury vapors, both short-term and long-term exposures to mercury vapors are possible. Acute exposure to high concentrations of mercury vapors can cause irritation of the respiratory tract and behavioral symptoms, such as irritability and hyperactivity. Chronic exposure can result in damage to the nervous system (tremors, memory loss, insomnia, etc.) and kidneys (proteinurea). Therefore, the JSC Toxicology Group recommends that stringent safety controls and verifications (vibrational testing, etc.) be applied to any hardware that contains elemental mercury that could yield

Utilization of dietary urea in rainbow trout.

Science.gov (United States)

Kaushik, S J; Dabrowski, K R; Dabrowska, H; Olah, E; Luquet, P

1983-01-01

Experiments were conducted to examine the potential utilization of dietary urea by rainbow trout. A control diet and two diets supplemented with 1 and 3% of urea were fed to fish. Postprandial levels of urea and ammonia in blood plasma, and postprandial excretion of these metabolites were followed during 24 h. Apparent digestibility of urea in rainbow trout was very high (greater than 98%). Maximum values of urea levels in plasma were reached 6 h (32.3 +/- 10.2 micrograms/ml) after a meal in the control fish and respectively 6 h (83.4 +/- 18.4 micrograms/ml) and 8 h (250.3 +/- 96.1 micrograms/ml) after a meal in trout fed 1 and 3% urea diets. Peaks of urea excretion rates appeared 7-9 h after meal, coinciding with the highest circulating urea concentration. Total daily urea excretion amounted to 5.53, 10.43 and 33.80 mg urea N/100 mg N intake in trout fed the control, 1 and 3% urea diets, respectively. It is concluded that the dietary urea is readily absorbed in the digestive tract of trout but is totally excreted thus leading to no beneficial effect on nitrogen balance. This excretion of urea also takes place passively without any increase in energy demands.

Factors influencing the spawning migration of female anadromous brown trout

DEFF Research Database (Denmark)

Svendsen, Jon Christian; Koed, Anders; Aarestrup, Kim

2004-01-01

Radio telemetry was employed to study movements of adult female anadromous brown trout Salmo trutta (sea trout) during upstream spawning migration and following spawning in a stream with tributaries. Sea trout were monitored by manual tracking and by automatic listening stations. The latter...... suggested that initiation of upstream migration was positively correlated with stream discharge. Individual sea trout performed repeated upstream migration 'initiations' (visits) to areas where they were detected by the automatic listening stations. The first and subsequent upstream migration 'initiations...

Farming of Freshwater Rainbow Trout in Denmark

DEFF Research Database (Denmark)

Jokumsen, Alfred; Svendsen, Lars Moeslund

Textbook on Farming of Freshwater Rainbow Trout in Denmark. Danish edition with the title: Opdræt af regnbueørred i Danmark......Textbook on Farming of Freshwater Rainbow Trout in Denmark. Danish edition with the title: Opdræt af regnbueørred i Danmark...

BIOMASS AND DENSITY OF BROWN AND RAINBOW TROUT IN NEW MEXICO STREAMS

Directory of Open Access Journals (Sweden)

Srečko Lainer

1995-03-01

Full Text Available Mean stream numerical density of the brown trout (Salmo trutta m. fario Linnaeus, 1758 and the rainbow trout (Onchorhynchus mykiss Walbaum, 1792 was 0.090 fish/m2 of which brown trout averaged 69% (72% in total biomass in 15 high-elevation New Mexico streams (1,661-2,560 m above sea level. Total trout density varied from 0.008/m2 in 1988 and 1989. Mean trout density ranged between 0.023-0.121 fish/m2 at site s open to public fishing. Considerably higher densities (0.142-0.409 fish/m2 were observed at sites closed for fishing. In the seven selected streams shared by both species, brown trout density exceeded rainbow trout density except at the two sites closed to fishing. Brown trout were stocked only as fingerlings (average 7,000 fish/stream/year while rainbow trout were stocked only in harvestable sizes (11,000 fish/stream/year. Reported total trout yield rates exceeded the total number of fish estimated to be in the stream by 1.01 to 11.63 in most small streams open to fishing. The proportional stock density (PSD ranged between O and 50 percent. Streams with low to moderate intensities of fishing had the highest PSD.

B cell signatures of BCWD-resistant and susceptible lines of rainbow trout: a shift towards more EBF-expressing progenitors and fewer mature B cells in resistant animals.

Science.gov (United States)

Zwollo, Patty; Ray, Jocelyn C; Sestito, Michael; Kiernan, Elizabeth; Wiens, Gregory D; Kaattari, Steve; StJacques, Brittany; Epp, Lidia

2015-01-01

Bacterial cold water disease (BCWD) is a chronic disease of rainbow trout, and is caused by the Gram-negative bacterium Flavobacterium psychrophilum (Fp), a common aquaculture pathogen. The National Center for Cool and Cold Water Aquaculture has bred two genetic lines of rainbow trout: a line of Fp-resistant trout (ARS-Fp-R or R-line trout) and a line of susceptible trout (ARS-Fp-S, or S-line). Little is known about how phenotypic selection alters immune response parameters or how such changes relate to genetic disease resistance. Herein, we quantify interindividual variation in the distribution and abundance of B cell populations (B cell signatures) and examine differences between genetic lines of naive animals. There are limited trout-specific cell surface markers currently available to resolve B cell subpopulations and thus we developed an alternative approach based on detection of differentially expressed transcription factors and intracellular cytokines. B cell signatures were compared between R-line and S-line trout by flow cytometry using antibodies against transcription factors early B cell factor-1 (EBF1) and paired domain box protein Pax5, the pro-inflammatory cytokine IL-1β, and the immunoglobulin heavy chain mu. R-line trout had higher percentages of EBF(+) B myeloid/ progenitor and pre-B cells in PBL, anterior and posterior kidney tissues compared to S-line trout. The opposite pattern was detected in more mature B cell populations: R-line trout had lower percentages of both IgM(+) mature B cells and IgM-secreting cells in anterior kidney and PBL compared to S-line trout. In vitro LPS-activation studies of PBL and spleen cell cultures revealed no significant induction differences between R-line and S-line trout. Together, our findings suggest that selective resistance to BCWD may be associated with shifts in naive animal developmental lineage commitment that result in decreased B lymphopoiesis and increased myelopoiesis in BCWD resistant trout relative

Intracellular diffusion restrictions in isolated cardiomyocytes from rainbow trout

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Birkedal Rikke

2009-12-01

Full Text Available Abstract Background Restriction of intracellular diffusion of adenine nucleotides has been studied intensively on adult rat cardiomyocytes. However, their cause and role in vivo is still uncertain. Intracellular membrane structures have been suggested to play a role. We therefore chose to study cardiomyocytes from rainbow trout (Oncorhynchus mykiss, which are thinner and have fewer intracellular membrane structures than adult rat cardiomyocytes. Previous studies suggest that trout permeabilized cardiac fibers also have diffusion restrictions. However, results from fibers may be affected by incomplete separation of the cells. This is avoided when studying permeabilized, isolated cardiomyocytes. The aim of this study was to verify the existence of diffusion restrictions in trout cardiomyocytes by comparing ADP-kinetics of mitochondrial respiration in permeabilized fibers, permeabilized cardiomyocytes and isolated mitochondria from rainbow trout heart. Experiments were performed at 10, 15 and 20°C in the absence and presence of creatine. Results Trout cardiomyocytes hypercontracted in the solutions used for mammalian cardiomyocytes. We developed a new solution in which they retained their shape and showed stable steady state respiration rates throughout an experiment. The apparent ADP-affinity of permeabilized cardiomyocytes was different from that of fibers. It was higher, independent of temperature and not increased by creatine. However, it was still about ten times lower than in isolated mitochondria. Conclusions The differences between fibers and cardiomyocytes suggest that results from trout heart fibers were affected by incomplete separation of the cells. However, the lower ADP-affinity of cardiomyocytes compared to isolated mitochondria indicate that intracellular diffusion restrictions are still present in trout cardiomyocytes despite their lower density of intracellular membrane structures. The lack of a creatine effect indicates that

Persistence of Tetracapsuloides bryosalmonae (Myxozoa) in chronically infected brown trout Salmo trutta.

Science.gov (United States)

Abd-Elfattah, Ahmed; Kumar, Gokhlesh; Soliman, Hatem; El-Matbouli, Mansour

2014-08-21

Proliferative kidney disease (PKD) is a widespread disease of farmed and wild salmonid populations in Europe and North America, caused by the myxozoan parasite Tetracapsuloides bryosalmonae. Limited studies have been performed on the epidemiological role in spread of the disease played by fish that survive infection with T. bryosalmonae. The aim of the present study was to evaluate the persistence of T. bryosalmonae developmental stages in chronically infected brown trout Salmo trutta up to 2 yr after initial exposure to laboratory-infected colonies of the parasite's alternate host, the bryozoan Fredericella sultana. Kidney, liver, spleen, intestine, brain, gills and blood were sampled 24, 52, 78 and 104 wk post-exposure (wpe) and tested for T. bryosalmonae by PCR and immunohistochemistry (IHC). Cohabitation trials with specific pathogen free (SPF) F. sultana colonies were conducted to test the viability of T. bryosalmonae. PCR detected T. bryosalmonae DNA in all tissue samples collected at the 4 time points. Developmental stages of T. bryosalmonae were demonstrated by IHC in most samples at the 4 time points. Cohabitation of SPF F. sultana with chronically infected brown trout resulted in successful transmission of T. bryosalmonae to the bryozoan. This study verified the persistence of T. bryosalmonae in chronically infected brown trout and their ability to infect the bryozoan F. sultana up to 104 wpe.

Phytoremediation of Ionic and Methyl Mercury Pollution

Energy Technology Data Exchange (ETDEWEB)

Meagher, Richard B.

2005-06-01

control the chemical speciation, electrochemical state, transport, and aboveground binding of mercury in order to manage this toxicant. To advance this mercury phytoremediation strategy, our planned research focuses on the following Specific Aims: (1) to increase the transport of mercury to aboveground tissue; (2) to identify small mercury binding peptides that enhance hyperaccumulation aboveground; (3) to test the ability of multiple genes acting together to enhance resistance and hyperaccumulation; (4) to construct a simple molecular system for creating male/female sterility, allowing engineered grass, shrub, and tree species to be released indefinitely at contaminated sites; (5) to test the ability of transgenic cottonwood and rice plants to detoxify ionic mercury and prevent methylmercury release from contaminated sediment; and (6) to initiate field testing with transgenic cottonwood and rice for the remediation of methylmercury and ionic mercury. The results of these experiments will enable the phytoremediation of methyl- and ionic mercury by a wide spectrum of deep-rooted, fast-growing plants adapted to diverse environments. We have made significant progress on all six of these specific aims as summarized below.

Mercury in Nelson's Sparrow subspecies at breeding sites.

Directory of Open Access Journals (Sweden)

Virginia L Winder

Full Text Available BACKGROUND: Mercury is a persistent, biomagnifying contaminant that can cause negative effects on ecosystems. Marshes are often areas of relatively high mercury methylation and bioaccumulation. Nelson's Sparrows (Ammodramus nelsoni use marsh habitats year-round and have been documented to exhibit tissue mercury concentrations that exceed negative effects thresholds. We sought to further characterize the potential risk of Nelson's Sparrows to mercury exposure by sampling individuals from sites within the range of each of its subspecies. METHODOLOGY/PRINCIPAL FINDINGS: From 2009 to 2011, we captured adult Nelson's Sparrows at sites within the breeding range of each subspecies (A. n. nelsoni: Grand Forks and Upham, North Dakota; A. n. alterus: Moosonee, Ontario; and A. n. subvirgatus: Grand Manan Island, New Brunswick and sampled breast feathers, the first primary feather (P1, and blood for total mercury analysis. Mean blood mercury in nelsoni individuals captured near Grand Forks ranged from 0.84 ± 0.37 to 1.65 ± 1.02 SD ppm among years, between 2.0 and 4.9 times as high as concentrations at the other sites (P<0.01. Breast feather mercury did not vary among sites within a given sampling year (site means ranged from 0.98 ± 0.69 to 2.71 ± 2.93 ppm. Mean P1 mercury in alterus (2.96 ± 1.84 ppm fw was significantly lower than in any other sampled population (5.25 ± 2.24-6.77 ± 3.51 ppm; P ≤ 0.03. CONCLUSIONS/SIGNIFICANCE: Our study further characterized mercury in Nelson's Sparrows near Grand Forks; we documented localized and potentially harmful mercury concentrations, indicating that this area may represent a biological mercury hotspot. This finding warrants further research to determine if wildlife populations of conservation or recreational interest in this area may be experiencing negative effects due to mercury exposure. We present preliminary conclusions about the risk of each sampled population to mercury exposure.

Metamorphosis of Ichthyophonus Schizonts Transiting the Gastrointestinal Tract of Experimentally Exposed Rainbow Trout.

Science.gov (United States)

Kocan, R M; LaPatra, S E

2017-12-08

Other than the initial infectious cell, schizonts are the only stage of the parasite Ichthyophonus sp. that has been identified in the tissues of a living host, and they are known to initiate new infections when ingested by a suitable host. However, after feeding Ichthyophonus-infected tissue to Rainbow Trout Oncorhynchus mykiss, we observed that once infection was initiated, some schizonts proceeded to develop into several other morphologic forms indistinguishable from those previously described from recently deceased hosts, decomposing infected corpses, and in vitro culture. It appeared that not all schizonts participated in the infection process; some initiated infection, as expected, while others passed into the intestines, where they morphed into multiple cell types (e.g., schizonts, some with partially digested or ruptured capsules, ameboid plasmodia, merozoites, hyphenated cells, and empty capsules). Some of these cells were viable when cultured, but none was infectious to naïve Rainbow Trout when administered by gavage. We posit that (1) not all tissue schizonts are programmed to perform the same function or (2) not all respond similarly to their environment. After consumption by a piscivore, those schizonts that do not initiate an infection do not die but rather metamorphose into different cell types as they transit the gastrointestinal tract and are ultimately released back into the aquatic environment through defecation. The fate of these cells after exiting the host is presently unknown, but they likely represent a segment of the Ichthyophonus life cycle. © 2017 American Fisheries Society.

Movement and mortality of stocked brown trout in a stream

DEFF Research Database (Denmark)

Aarestrup, Kim; Jepsen, Niels; Koed, Anders

2005-01-01

The movement and mortality of stocked brown trout Salmo trutta were investigated using radio telemetry. Four brown trout left the study area whereas the remaining fish were stationary. After 5 weeks, 13 out of 50 tagged brown trout were still alive in the stream. Surviving fish had a significantly...

Introduced brown trout alter native acanthocephalan infections in native fish.

Science.gov (United States)

Paterson, Rachel A; Townsend, Colin R; Poulin, Robert; Tompkins, Daniel M

2011-09-01

1. Native parasite acquisition provides introduced species with the potential to modify native host-parasite dynamics by acting as parasite reservoirs (with the 'spillback' of infection increasing the parasite burdens of native hosts) or sinks (with the 'dilution' of infection decreasing the parasite burdens of native hosts) of infection. 2. In New Zealand, negative correlations between the presence of introduced brown trout (Salmo trutta) and native parasite burdens of the native roundhead galaxias (Galaxias anomalus) have been observed, suggesting that parasite dilution is occurring. 3. We used a multiple-scale approach combining field observations, experimental infections and dynamic population modelling to investigate whether native Acanthocephalus galaxii acquisition by brown trout alters host-parasite dynamics in native roundhead galaxias. 4. Field observations demonstrated higher infection intensity in introduced trout than in native galaxias, but only small, immature A. galaxii were present in trout. Experimental infections also demonstrated that A. galaxii does not mature in trout, although parasite establishment and initial growth were similar in the two hosts. Taken together, these results support the hypothesis that trout may serve as an infection sink for the native parasite. 5. However, dynamic population modelling predicts that A. galaxii infections in native galaxias should at most only be slightly reduced by dilution in the presence of trout. Rather, model exploration indicates parasite densities in galaxias are highly sensitive to galaxias predation on infected amphipods, and to relative abundances of galaxias and trout. Hence, trout presence may instead reduce parasite burdens in galaxias by either reducing galaxias density or by altering galaxias foraging behaviour. © 2011 The Authors. Journal of Animal Ecology © 2011 British Ecological Society.

EVALUATION OF TOTAL MERCURY CONTENT IN MUSCLE TISSUE OF MARINE FISH AND ANIMALS

OpenAIRE

Daniel Bajčan; Július Árvay; Janette Musilová

2013-01-01

Nowdays, a degree of contamination by heavy metals can be observed in the environment. Heavy metals have serious effects on all living organisms because they can accumulate in lethal or sublethal concentrations in the various parts of food chain and so they can cause different health problems like cardiovascular and cancer diseases. Marine fish and animals are one of the bigges source of mercury in human food. Therefore this work is focused to the rate of mercury content in muscle tisuues of ...

Evaluation of glutamic acid and glycine as sources of nonessential amino acids for lake trout (Salvelinus namaycush) and rainbow trout (Salmo gairdnerii)

Science.gov (United States)

Hughes, S.G.

1985-01-01

1. A semi-purified test diet which contained either glutamic acid or glycine as the major source of nonessential amino acids (NEAA) was fed to lake and rainbow trout.2. Trout fed the diet containing glutamic acid consistently showed better growth and feed conversion efficiencies than those fed the diets containing glycine.3. The data indicate that these trout utilize glutamic acid more efficiently than glycine when no other major sources of NEAA are present.

Experimental infection with epizootic haematopoietic necrosis virus (EHNV of rainbow trout (Oncorhynchus mykiss Walbaum and European perch (Perca fluviatilis L.

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Borzym Ewa

2015-12-01

Full Text Available The aim of this study was the determination of the susceptibility of Polish farmed redfin perch (Perca fluviatilis L. and rainbow trout (Oncorhynchus mykiss Walbaum to experimental infection with haematopoietic necrosis virus (EHNV. A bath challenge model was tested at two temperature ranges: 13-15°C and 20-22°C. After 7 d, the first clinical signs and mortality were observed in fish kept at these temperatures. Significantly more mortality cases were reported in the redfin perch population, reaching a maximum of 24% compared with 12% in the rainbow trout group at 20-22°C. EHNV was reisolated from redfin perch and rainbow trout tissue in cell culture and the infection was confirmed by a molecular method and histopathology during the duration of the experiment. This study revealed that fish from Polish farms can be susceptible to EHNV even at lower temperatures.

Spatial and temporal movement dynamics of brook Salvelinus fontinalis and brown trout Salmo trutta

Science.gov (United States)

Davis, L.A.; Wagner, Tyler; Barton, Meredith L.

2015-01-01

Native eastern brook trout Salvelinus fontinalis and naturalized brown trout Salmo trutta occur sympatrically in many streams across the brook trout’s native range in the eastern United States. Understanding within- among-species variability in movement, including correlates of movement, has implications for management and conservation. We radio tracked 55 brook trout and 45 brown trout in five streams in a north-central Pennsylvania, USA watershed to quantify the movement of brook trout and brown trout during the fall and early winter to (1) evaluate the late-summer, early winter movement patterns of brook trout and brown trout, (2) determine correlates of movement and if movement patterns varied between brook trout and brown trout, and (3) evaluate genetic diversity of brook trout within and among study streams, and relate findings to telemetry-based observations of movement. Average total movement was greater for brown trout (mean ± SD = 2,924 ± 4,187 m) than for brook trout (mean ± SD = 1,769 ± 2,194 m). Although there was a large amount of among-fish variability in the movement of both species, the majority of movement coincided with the onset of the spawning season, and a threshold effect was detected between stream flow and movement: where movement increased abruptly for both species during positive flow events. Microsatellite analysis of brook trout revealed consistent findings to those found using radio-tracking, indicating a moderate to high degree of gene flow among brook trout populations. Seasonal movement patterns and the potential for relatively large movements of brook and brown trout highlight the importance of considering stream connectivity when restoring and protecting fish populations and their habitats.

Organically bound tritium (OBT) formation in rainbow trout (Oncorhynchus mykiss): HTO and OBT-spiked food exposure experiments

International Nuclear Information System (INIS)

Kim, S.B.; Shultz, C.; Stuart, M.; McNamara, E.; Festarini, A.; Bureau, D.P.

2013-01-01

In order to determine the rate of organically bound tritium (OBT) formation, rainbow trout (Oncorhynchus mykiss) were exposed to tritiated water (HTO) or OBT-spiked food. The HTO (in water) exposure study was conducted using a tritium activity concentration of approximately 7000 Bq/L and the OBT (in food) exposure study was conducted using a tritium activity concentration of approximately 30,000 Bq/L. Fish in both studies were expected to be exposed to similar tritium levels assuming 25% incorporation of the tritiated amino acids found in the food. Four different sampling campaigns of HTO exposure (Day 10, 30, 70, 140) and five different sampling campaigns of OBT-spiked food exposure (Day 9, 30, 70, 100, 140) were conducted to measure HTO and OBT activity concentrations in fish tissues. OBT depuration was also evaluated over a period of 30 days following the 140 d exposure studies. The results suggested that the OBT formation rate was slower when the fish were exposed to HTO compared to when the fish were ingesting OBT. In addition, the results indicated that OBT can bioaccumulate in fish tissues following OBT-spiked food exposure. - Highlights: ► The rate of organically bound tritium (OBT) formation was determined in rainbow trout. ► Rainbow trout were exposed to tritium in the form of tritiated water (HTO) and OBT-spiked food. ► OBT formation rate was slower when the fish were exposed to HTO compared to when the fish were ingesting OBT.

Total mercury of selected fish species from Laguna de Bay

International Nuclear Information System (INIS)

Relon, Milagros Lontoc

1996-01-01

Dalag Ophicephalus striatus Block, kanduli Arius thalassinus Ruppell, bia Amblygobius phalaena Cuvier et Valenciennes and tilapia Tilapia nilotica Linnnaeus collected from Laguna de Bay between Taguig and Binangonan area in August 1989 to July 1990 were analyzed for total mercury by atomic absorption spectrometry. The highest metal concentration in soft muscle tissue was observed in Dalag followed by kanduli, less in bia and least in tilapia with mean values of 0.021, 0.020, 0.013, and 0.008 ug/g, respectively. Analysis using two-way ANOVA showed a significant difference in the mean total mercury in ug/g in the difference fish samples, among the different months and the interaction between these two variables. Mean total mercury of the four fish samples were significantly higher in April than in October. The results show that the levels of total mercury in the fish samples are below the World Health Organization maximum tolerable consumption of mercury in food of 300 ug or 0.03 mg of total mercury per week. (author)

Comparison of biochemical parameters of rainbow trout (Oncorhynchus mykiss) reared in two different trout farms'

Science.gov (United States)

Karatas, Tayfun

2016-04-01

The aim of this study was to compare biochemical parameters of cultured rainbow trouts (Oncorhynchus mykiss, Walbaum, 1972) reared in two different trout farms' (Agri and Erzurum). The average weights of fish were 150±10gr for first station (Agri), 230±10gr for second station (Erzurum). Fishes used in research were randomly caught from pools, and fifteen pieces were used for each group. Fishes were fed with commercial trout feed with 45-50% crude protein twice a day. The levels of AST, ALT, LDL, total cholesterol and triglyceride in the second station (Erzurum) were found to be higher (p<0.05) than that of first station (Agri). Whereas, the levels of HDL in the second station (Erzurum) were found to be lower (p<0.05) than that of first station (Agri). Differences in the levels of total cholesterol and AST, ALT, HDL, LDL, triglyceride may be associated with size, sex, sexual maturity and environmental conditions (temperature, pH, hardness and dissolved oxygen).

Active methods of mercury removal from flue gases.

Science.gov (United States)

Marczak, Marta; Budzyń, Stanisław; Szczurowski, Jakub; Kogut, Krzysztof; Burmistrz, Piotr

2018-03-23

Due to its adverse impact on health, as well as its global distribution, long atmospheric lifetime and propensity for deposition in the aquatic environment and in living tissue, the US Environmental Protection Agency (US EPA) has classified mercury and its compounds as a severe air quality threat. Such widespread presence of mercury in the environment originates from both natural and anthropogenic sources. Global anthropogenic emission of mercury is evaluated at 2000 Mg year -1 . According to the National Centre for Emissions Management (Pol. KOBiZE) report for 2014, Polish annual mercury emissions amount to approximately 10 Mg. Over 90% of mercury emissions in Poland originate from combustion of coal.The purpose of this paper was to understand mercury behaviour during sub-bituminous coal and lignite combustion for flue gas purification in terms of reduction of emissions by active methods. The average mercury content in Polish sub-bituminous coal and lignite was 103.7 and 443.5 μg kg -1 . The concentration of mercury in flue gases emitted into the atmosphere was 5.3 μg m -3 for sub-bituminous coal and 17.5 μg m -3 for lignite. The study analysed six low-cost sorbents with the average achieved efficiency of mercury removal from 30.6 to 92.9% for sub-bituminous coal and 22.8 to 80.3% for lignite combustion. Also, the effect of coke dust grain size was examined for mercury sorptive properties. The fine fraction of coke dust (CD) adsorbed within 243-277 μg Hg kg -1 , while the largest fraction at only 95 μg Hg kg -1 . The CD fraction physical oxidation of Hg in the flue gas, its effectiveness has increased twofold.

The effects of exogenous cortisol on myostatin transcription in rainbow trout, Oncorhynchus mykiss.

Science.gov (United States)

Galt, Nicholas J; Froehlich, Jacob Michael; Remily, Ethan A; Romero, Sinibaldo R; Biga, Peggy R

2014-09-01

Glucocorticoids (GCs) strongly regulate myostatin expression in mammals via glucocorticoid response elements (GREs), and bioinformatics methods suggest that this regulatory mechanism is conserved among many vertebrates. However, the multiple myostatin genes found in some fishes may be an exception. In silico promoter analyses of the three putative rainbow trout (Oncorhynchus mykiss) myostatin promoters have failed to identify putative GREs, suggesting a divergence in myostatin function. Therefore, we hypothesized that myostatin mRNA expression is not regulated by glucocorticoids in rainbow trout. In this study, both juvenile rainbow trout and primary trout myoblasts were treated with cortisol to examine the effects on myostatin mRNA expression. Results suggest that exogenous cortisol does not regulate myostatin-1a and -1b expression in vivo, as myostatin mRNA levels were not significantly affected by cortisol treatment in either red or white muscle tissue. In red muscle, myostatin-2a levels were significantly elevated in the cortisol treatment group relative to the control, but not the vehicle control, at both 12 h and 24 h post-injection. As such, it is unclear if cortisol was acting alone or in combination with the vehicle. Cortisol increased myostatin-1b expression in a dose-dependent manner in vitro. Further work is needed to determine if this response is the direct result of cortisol acting on the myostatin-1b promoter or through an alternative mechanism. These results suggest that regulation of myostatin by cortisol may not be as highly conserved as previously thought and support previous work that describes potential functional divergence of the multiple myostatin genes in fishes. Copyright © 2014 Elsevier Inc. All rights reserved.

Movement of resident rainbow trout transplanted below a barrier to anadromy

Science.gov (United States)

Wilzbach, Margaret A.; Ashenfelter, Mark J.; Ricker, Seth J.

2012-01-01

We tracked the movement of resident coastal rainbow trout Oncorhynchus mykiss irideus that were experimentally transplanted below a migration barrier in a northern California stream. In 2005 and 2006, age-1 and older rainbow trout were captured above a 5-m-high waterfall in Freshwater Creek and individually marked with passive integrated transponder tags. Otolith microchemistry confirmed that the above-barrier trout were the progeny of resident rather than anadromous parents, and genetic analysis indicated that the rainbow trout were introgressed with cutthroat trout O. clarkii. At each of three sampling events, half of the tagged individuals (n = 22 and 43 trout in 2005 and 2006, respectively) were released 5 km downstream from the waterfall (approximately 10 km upstream from tidewater), and an equal number of tagged individuals were released above the barrier. Tagged individuals were subsequently relocated with stationary and mobile antennae or recaptured in downstream migrant traps, or both, until tracking ceased in October 2007. Most transplanted individuals remained within a few hundred meters of their release location. Three individuals, including one rainbow trout released above the waterfall, were last detected in the tidally influenced lower creek. Two additional tagged individuals released above the barrier were found alive in below-barrier reaches and had presumably washed over the falls. Two of seven tagged rainbow trout captured in downstream migrant traps had smolted and one was a presmolt. The smoltification of at least some individuals, coupled with above-barrier "leakage" of fish downstream, suggests that above-barrier resident trout have the potential to exhibit migratory behavior and to enter breeding populations of steelhead (anadromous rainbow trout) within the basin.

Mercury in Nelson's Sparrow Subspecies at Breeding Sites

Science.gov (United States)

Winder, Virginia L.; Emslie, Steven D.

2012-01-01

Background Mercury is a persistent, biomagnifying contaminant that can cause negative effects on ecosystems. Marshes are often areas of relatively high mercury methylation and bioaccumulation. Nelson's Sparrows (Ammodramus nelsoni) use marsh habitats year-round and have been documented to exhibit tissue mercury concentrations that exceed negative effects thresholds. We sought to further characterize the potential risk of Nelson's Sparrows to mercury exposure by sampling individuals from sites within the range of each of its subspecies. Methodology/Principal Findings From 2009 to 2011, we captured adult Nelson's Sparrows at sites within the breeding range of each subspecies (A. n. nelsoni: Grand Forks and Upham, North Dakota; A. n. alterus: Moosonee, Ontario; and A. n. subvirgatus: Grand Manan Island, New Brunswick) and sampled breast feathers, the first primary feather (P1), and blood for total mercury analysis. Mean blood mercury in nelsoni individuals captured near Grand Forks ranged from 0.84±0.37 to 1.65±1.02 SD ppm among years, between 2.0 and 4.9 times as high as concentrations at the other sites (Pmercury did not vary among sites within a given sampling year (site means ranged from 0.98±0.69 to 2.71±2.93 ppm). Mean P1 mercury in alterus (2.96±1.84 ppm fw) was significantly lower than in any other sampled population (5.25±2.24–6.77±3.51 ppm; P≤0.03). Conclusions/Significance Our study further characterized mercury in Nelson's Sparrows near Grand Forks; we documented localized and potentially harmful mercury concentrations, indicating that this area may represent a biological mercury hotspot. This finding warrants further research to determine if wildlife populations of conservation or recreational interest in this area may be experiencing negative effects due to mercury exposure. We present preliminary conclusions about the risk of each sampled population to mercury exposure. PMID:22384194

Agonistic behavior among three stocked trout species in a novel reservoir fish community

Science.gov (United States)

Budy, Phaedra; Hafen, Konrad

2015-01-01

The popularity of reservoirs to support sport fisheries has led to the stocking of species that did not co-evolve, creating novel reservoir fish communities. In Utah, the Bear Lake strain of Bonneville Cutthroat Trout Oncorhynchus clarkii utah and tiger trout (female Brown Trout Salmo trutta × male Brook Trout Salvelinus fontinalis) are being more frequently added to a traditional stocking regimen consisting primarily of Rainbow TroutO. mykiss. Interactions between these three predatory species are not well understood, and studies evaluating community interactions have raised concern for an overall decrease of trout condition. To evaluate the potential for negative interactions among these species, we tested aggression in laboratory aquaria using three-species and pairwise combinations at three densities. Treatments were replicated before and after feeding. During the three-species trials Rainbow Trout initiated 24.8 times more aggressive interactions than Cutthroat Trout and 10.2 times more aggressive interactions than tiger trout, and tiger trout exhibited slightly (1.9 times) more aggressive initiations than Cutthroat Trout. There was no significant difference in behavior before versus after feeding for any species, and no indication of increased aggression at higher densities. Although Rainbow Trout in aquaria may benefit from their bold, aggressive behavior, given observations of decreased relative survival in the field, these benefits may be outweighed in reservoirs, possibly through unnecessary energy expenditure and exposure to predators.

Integrative functional analyses using rainbow trout selected for tolerance to plant diets reveal nutrigenomic signatures for soy utilization without the concurrence of enteritis.

Directory of Open Access Journals (Sweden)

Jason Abernathy

Full Text Available Finding suitable alternative protein sources for diets of carnivorous fish species remains a major concern for sustainable aquaculture. Through genetic selection, we created a strain of rainbow trout that outperforms parental lines in utilizing an all-plant protein diet and does not develop enteritis in the distal intestine, as is typical with salmonids on long-term plant protein-based feeds. By incorporating this strain into functional analyses, we set out to determine which genes are critical to plant protein utilization in the absence of gut inflammation. After a 12-week feeding trial with our selected strain and a control trout strain fed either a fishmeal-based diet or an all-plant protein diet, high-throughput RNA sequencing was completed on both liver and muscle tissues. Differential gene expression analyses, weighted correlation network analyses and further functional characterization were performed. A strain-by-diet design revealed differential expression ranging from a few dozen to over one thousand genes among the various comparisons and tissues. Major gene ontology groups identified between comparisons included those encompassing central, intermediary and foreign molecule metabolism, associated biosynthetic pathways as well as immunity. A systems approach indicated that genes involved in purine metabolism were highly perturbed. Systems analysis among the tissues tested further suggests the interplay between selection for growth, dietary utilization and protein tolerance may also have implications for nonspecific immunity. By combining data from differential gene expression and co-expression networks using selected trout, along with ontology and pathway analyses, a set of 63 candidate genes for plant diet tolerance was found. Risk loci in human inflammatory bowel diseases were also found in our datasets, indicating rainbow trout selected for plant-diet tolerance may have added utility as a potential biomedical model.

Disposition of naphthalene and its metabolites in the brain of rainbow trout (Salmo gairdneri)

International Nuclear Information System (INIS)

Collier, T.K.; Krahn, M.M.; Malins, D.C.

1980-01-01

Rainbow trout (Salmo gairdneri) were exposed to orally administered [ 3 H]naphthalene. Another group received naphthyl glucuronic acid and naphthyl sulfate via iv injection. Brain, liver, and blood were assayed for the parent compound and/or total metabolites. Individual naphthalene derivatives were determined by high-performance liquid chromatography (hplc) using either radiometric or on-line fluorimetric detection systems. Naphthalene concentrations in brain (8.2 pmol/mg dry wt at 16 hr after feeding) approximated those found at the same time in liver (7.4 pmol/mg dry wt). A nonconjugated naphthalene derivative, 1,2-dihydro-1,2-dihydroxynaphthalene, also accumulated in brain (0.041 pmol/mg dry wt after 16 hr), although to a lesser degree than in liver (0.10 pmol/mg dry wt after 16 hr). Conjugated naphthalene derivatives, 1-naphthyl sulfate and 1-naphthyl glucuronic acid, although present in liver and blood, were largely excluded from the brain. Low naphthalene hydroxylase activity (<2.0 pmol product formed/mg protein/min) indicated that the trout brain has a minimal ability to oxidize aromatic hydrocarbons. These findings suggest that the brain of adult trout is substantially different from other tissues (e.g., liver and blood) with respect to the disposition of naphthalene and its metabolites

Monitor and Protect Wigwam River Bull Trout for Koocanusa Reservoir : Summary of the Skookumchuck Creek Bull Trout Enumeration Project Final Report 2000-2002.

Energy Technology Data Exchange (ETDEWEB)

Baxter, Jeremy; Baxter, James S.

2002-12-01

This report summarizes the third and final year of a bull trout (Salvelinus confluentus) enumeration project on Skookumchuck Creek in southeastern British Columbia. The fence and traps were operated from September 6th to October 11th 2002 in order to enumerate post-spawning bull trout. During the study period a total of 309 bull trout were captured at the fence. In total, 16 fish of undetermined sex, 114 males and 179 females were processed at the fence. Length and weight data, as well as recapture information, were collected for these fish. An additional 41 bull trout were enumerated upstream of the fence by snorkeling prior to fence removal. Coupled with the fence count, the total bull trout enumerated during the project was 350 individuals. Several fish that were tagged in the lower Bull River were recaptured in 2002, as were repeat and alternate year spawners previously enumerated in past years at the fence. A total of 149 bull trout redds were enumerated on the ground in 2002, of which 143 were in the 3.0 km index section (river km 27.5-30.5) that has been surveyed over the past six years. The results of the three year project are summarized, and population characteristics are discussed.

Mercury exposure may influence fluctuating asymmetry in waterbirds.

Science.gov (United States)

Herring, Garth; Eagles-Smith, Collin A; Ackerman, Joshua T

2017-06-01

Variation in avian bilateral symmetry can be an indicator of developmental instability in response to a variety of stressors, including environmental contaminants. The authors used composite measures of fluctuating asymmetry to examine the influence of mercury concentrations in 2 tissues on fluctuating asymmetry within 4 waterbird species. Fluctuating asymmetry increased with mercury concentrations in whole blood and breast feathers of Forster's terns (Sterna forsteri), a species with elevated mercury concentrations. Specifically, fluctuating asymmetry in rectrix feather 1 was the most strongly correlated structural variable of those tested (wing chord, tarsus, primary feather 10, rectrix feather 6) with mercury concentrations in Forster's terns. However, for American avocets (Recurvirostra americana), black-necked stilts (Himantopus mexicanus), and Caspian terns (Hydroprogne caspia), the authors found no relationship between fluctuating asymmetry and either whole-blood or breast feather mercury concentrations, even though these species had moderate to elevated mercury exposure. The results indicate that mercury contamination may act as an environmental stressor during development and feather growth and contribute to fluctuating asymmetry of some species of highly contaminated waterbirds. Environ Toxicol Chem 2017;36:1599-1605. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

Hybridization between Yellowstone cutthroat trout and rainbow trout alters the expression of muscle growth-related genes and their relationships with growth patterns

Science.gov (United States)

Ostberg, Carl O.; Chase, Dorothy M.; Hauser, Lorenz

2015-01-01

Hybridization creates novel gene combinations that may generate important evolutionary novelty, but may also reduce existing adaptation by interrupting inherent biological processes, such as genotype-environment interactions. Hybridization often causes substantial change in patterns of gene expression, which, in turn, may cause phenotypic change. Rainbow trout (Oncorhynchus mykiss) and cutthroat trout (O. clarkii) produce viable hybrids in the wild, and introgressive hybridization with introduced rainbow trout is a major conservation concern for native cutthroat trout. The two species differ in body shape, which is likely an evolutionary adaptation to their native environments, and their hybrids tend to show intermediate morphology. The characterization of gene expression patterns may provide insights on the genetic basis of hybrid and parental morphologies, as well as on the ecological performance of hybrids in the wild. Here, we evaluated the expression of eight growth-related genes (MSTN-1a, MSTN-1b, MyoD1a, MyoD1b, MRF-4, IGF-1, IGF-2, and CAST-L) and the relationship of these genes with growth traits (length, weight, and condition factor) in six line crosses: both parental species, both reciprocal F1 hybrids, and both first-generation backcrosses (F1 x rainbow trout and F1 x cutthroat trout). Four of these genes were differentially expressed among rainbow, cutthroat, and their hybrids. Transcript abundance was significantly correlated with growth traits across the parent species, but not across hybrids. Our findings suggest that rainbow and cutthroat trout exhibit differences in muscle growth regulation, that transcriptional networks may be modified by hybridization, and that hybridization disrupts intrinsic relationships between gene expression and growth patterns that may be functionally important for phenotypic adaptations.

Phylogeography and taxonomic status of trout and salmon from the Ponto-Caspian drainages, with inferences on European Brown Trout evolution and taxonomy.

Science.gov (United States)

Ninua, Levan; Tarkhnishvili, David; Gvazava, Elguja

2018-03-01

Current taxonomy of western Eurasian trout leaves a number of questions open; it is not clear to what extent some species are distinct genetically and morphologically. The purpose of this paper was to explore phylogeography and species boundaries in freshwater and anadromous trout from the drainages of the Black and the Caspian Seas (Ponto-Caspian). We studied morphology and mitochondrial phylogeny, combining samples from the western Caucasus within the potential range of five nominal species of trout that are thought to inhabit this region, and using the sequences available from GenBank. Our results suggest that the genetic diversity of trout in the Ponto-Caspian region is best explained with the fragmentation of catchments. (1) All trout species from Ponto-Caspian belong to the same mitochondrial clade, separated from the other trout since the Pleistocene; (2) the southeastern Black Sea area is the most likely place of diversification of this clade, which is closely related to the clades from Anatolia; (3) The species from the Black Sea and the Caspian Sea drainages are monophyletic; (4) except for the basal lineage of the Ponto-Caspian clade, Salmo rizeensis , all the lineages produce anadromous forms; (5) genetic diversification within the Ponto-Caspian clade is related to Pleistocene glacial waves; (6) the described morphological differences between the species are not fully diagnostic, and some earlier described differences depend on body size; the differences between freshwater and marine forms exceed those between the different lineages. We suggest a conservative taxonomic approach, using the names S. rizeensis and Salmo labrax for trout from the Black Sea basin and Salmo caspius and Salmo ciscaucasicus for the fish from the Caspian basin.

Planet Mercury

Science.gov (United States)

1974-01-01

Mariner 10's first image of Mercury acquired on March 24, 1974. During its flight, Mariner 10's trajectory brought it behind the lighted hemisphere of Mercury, where this image was taken, in order to acquire important measurements with other instruments.This picture was acquired from a distance of 3,340,000 miles (5,380,000 km) from the surface of Mercury. The diameter of Mercury (3,031 miles; 4,878 km) is about 1/3 that of Earth.Images of Mercury were acquired in two steps, an inbound leg (images acquired before passing into Mercury's shadow) and an outbound leg (after exiting from Mercury's shadow). More than 2300 useful images of Mercury were taken, both moderate resolution (3-20 km/pixel) color and high resolution (better than 1 km/pixel) black and white coverage.

Demographic characteristics of an adfluvial bull trout population in Lake Pend Oreille, Idaho

Science.gov (United States)

McCubbins, Jonathan L; Hansen, Michael J.; DosSantos, Joseph M; Dux, Andrew M

2016-01-01

Introductions of nonnative species, habitat loss, and stream fragmentation have caused the Bull Trout Salvelinus confluentus to decline throughout much of its native distribution. Consequently, in June 1998, the Bull Trout was listed under the U.S. Endangered Species Act as threatened. The Bull Trout has existed in Lake Pend Oreille and its surrounding tributaries since the last ice age, and the lake once supported a world-renowned Bull Trout fishery. To quantify the current status of the Bull Trout population in Lake Pend Oreille, Idaho, we compared the mean age, growth, maturity, and abundance with reports in a study conducted one decade earlier. Abundance was estimated by mark–recapture for Bull Trout caught in trap nets and gill nets set in Lake Pend Oreille during ongoing suppression netting of Lake Trout S. namaycushin 2007–2008. Bull Trout sampled in 2006–2008 were used to estimate age structure, survival, growth, and maturity. Estimated Bull Trout abundance was similar to that estimated one decade earlier in Lake Pend Oreille. Bull Trout residing in Lake Pend Oreille between 2006 and 2008 were between ages 4 and 14 years; their growth was fastest between ages 1 and 2 and slowed thereafter. Male and female Bull Trout matured at a similar age, but females grew faster than males, thereby maturing at a larger size. Our findings suggest that management has effectively addressed current threats to increase the likelihood of long-term persistence of the Bull Trout population in Lake Pend Oreille.

Metals in tissues of migrant semipalmated sandpipers (Calidris pusilla) from Delaware Bay, New Jersey

International Nuclear Information System (INIS)

Burger, Joanna; Gochfeld, Michael; Niles, Lawrence; Dey, Amanda; Jeitner, Christian; Pittfield, Taryn; Tsipoura, Nellie

2014-01-01

There is an abundance of field data on levels of metals for feathers in a variety of birds, but relatively few data for tissues, especially for migrant species from one location. In this paper we examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in muscle, liver, brain, fat and breast feathers from migrant semipalmated sandpipers (Calidris pusilla) collected from Delaware Bay, New Jersey. Our primary objectives were to (1) examine variation as a function of tissue, (2) determine the relationship of metal levels among tissues, and (3) determine the selenium:mercury molar ratio in different tissues since selenium is thought to protect against mercury toxicity. We were also interested in whether the large physiological changes that occur while shorebirds are on Delaware Bay (e.g. large weight gains in 2–3 weeks) affected metal levels, especially in the brain. There were significant differences among tissues for all metals. The brain had the lowest levels of arsenic and cadmium, and was tied for the lowest levels of all other metals except lead and selenium. Correlations among metals in tissues were varied, with mercury levels being positively correlated for muscle and brain, and for liver and breast feathers. Weights vary among individuals at the Delaware Bay stopover, as they arrive light, and gain weight prior to migration north. Bird weight and levels of arsenic, cadmium, and selenium in the brain were negatively correlated, while they were positively correlated for lead. There was no positive correlation for mercury in the brain as a function of body weight. The selenium:mercury molar ratio varied significantly among tissues, with brain (ratio of 141) and fat having the highest ratios, and liver and breast feathers having the lowest. In all cases, the ratio was above 21, suggesting the potential for amelioration of mercury toxicity. - Highlights: • Metal levels were examined for migrant semipalmated sandpipers. • There

Metals in tissues of migrant semipalmated sandpipers (Calidris pusilla) from Delaware Bay, New Jersey

Energy Technology Data Exchange (ETDEWEB)

Burger, Joanna, E-mail: burger@biology.rutgers.edu [Division of Life Sciences, Rutgers University, 604 Allison Road, Piscataway, NJ (United States); Environmental and Occupational Health Sciences Institute (EOHSI), Piscataway, NJ (United States); Gochfeld, Michael [Environmental and Occupational Health Sciences Institute (EOHSI), Piscataway, NJ (United States); Environmental and Occupational Medicine, Rutgers RWJ Medical School, Rutgers University, Piscataway, NJ (United States); Niles, Lawrence [Conserve Wildlife, 109 Market Lane, Greenwich, NJ (United States); Dey, Amanda [NJ Department of Environmental Protection, Endangered and Nongame Species Program, Trenton, NJ (United States); Jeitner, Christian; Pittfield, Taryn [Division of Life Sciences, Rutgers University, 604 Allison Road, Piscataway, NJ (United States); Environmental and Occupational Health Sciences Institute (EOHSI), Piscataway, NJ (United States); Tsipoura, Nellie [New Jersey Audubon Society, 11 Hardscrabble Rd, Bernardsville, NJ (United States)

2014-08-15

There is an abundance of field data on levels of metals for feathers in a variety of birds, but relatively few data for tissues, especially for migrant species from one location. In this paper we examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in muscle, liver, brain, fat and breast feathers from migrant semipalmated sandpipers (Calidris pusilla) collected from Delaware Bay, New Jersey. Our primary objectives were to (1) examine variation as a function of tissue, (2) determine the relationship of metal levels among tissues, and (3) determine the selenium:mercury molar ratio in different tissues since selenium is thought to protect against mercury toxicity. We were also interested in whether the large physiological changes that occur while shorebirds are on Delaware Bay (e.g. large weight gains in 2–3 weeks) affected metal levels, especially in the brain. There were significant differences among tissues for all metals. The brain had the lowest levels of arsenic and cadmium, and was tied for the lowest levels of all other metals except lead and selenium. Correlations among metals in tissues were varied, with mercury levels being positively correlated for muscle and brain, and for liver and breast feathers. Weights vary among individuals at the Delaware Bay stopover, as they arrive light, and gain weight prior to migration north. Bird weight and levels of arsenic, cadmium, and selenium in the brain were negatively correlated, while they were positively correlated for lead. There was no positive correlation for mercury in the brain as a function of body weight. The selenium:mercury molar ratio varied significantly among tissues, with brain (ratio of 141) and fat having the highest ratios, and liver and breast feathers having the lowest. In all cases, the ratio was above 21, suggesting the potential for amelioration of mercury toxicity. - Highlights: • Metal levels were examined for migrant semipalmated sandpipers. • There

Regulation of Na+/K+-ATPase activity by nitric oxide in the kidney and gill of the brown trout (Salmo trutta)

DEFF Research Database (Denmark)

Tipsmark, Christian K; Madsen, Steffen S

2003-01-01

In teleost fish, successful osmoregulation involves controlled ion transport mechanisms in kidney and gill epithelia. In this study, the effect of nitric oxide (NO) on Na(+)/K(+)-ATPase was investigated in vitro in these two tissues in brown trout (Salmo trutta) acclimated to freshwater...

Influence of ontogeny and environmental exposure on mercury accumulation in muscle and liver of male Round Stingrays.

Science.gov (United States)

Lyons, Kady; Carlisle, Aaron B; Lowe, Christopher G

2017-09-01

Mercury tissue distribution and its dynamics are poorly understood in elasmobranchs. Total mercury was measured in liver and muscle of male Round Stingrays (Urobatis halleri) from Seal Beach, California, an anthropogenically impacted site, and from the offshore island of Santa Catalina, a less impacted site. Stable isotope analysis was also performed on the muscle and red blood cells (RBCs) of a subset of rays over a range of age classes to investigate mercury accumulation with respect to trophic ecology. Mercury in both tissues was found to be significantly greater in adults than juveniles in mainland rays; however, liver mercury accumulation drastically increased after maturity and was significantly greater in mainland adult rays than Catalina rays. There were no patterns in δ 15 N or δ 13 C with size in muscle; however, there were indications of seasonal changes in RBC δ 15 N, suggesting short term shifts in diet or behavior is likely linked to reproductive status as is mercury accumulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mercury contamination in bats from the central United States.

Science.gov (United States)

Korstian, Jennifer M; Chumchal, Matthew M; Bennett, Victoria J; Hale, Amanda M

2018-01-01

Mercury (Hg) is a highly toxic metal that has detrimental effects on wildlife. We surveyed Hg concentrations in 10 species of bats collected at wind farms in the central United States and found contamination in all species. Mercury concentration in fur was highly variable both within and between species (range: 1.08-10.52 µg/g). Despite the distance between sites (up to 1200 km), only 2 of the 5 species sampled at multiple locations had fur Hg concentrations that differed between sites. Mercury concentrations observed in the present study all fell within the previously reported ranges for bats collected from the northeastern United States and Canada, although many of the bats we sampled had lower maximum Hg concentrations. Juvenile bats had lower concentrations of Hg in fur compared with adult bats, and we found no significant effect of sex on Hg concentrations in fur. For a subset of 2 species, we also measured Hg concentration in muscle tissue; concentrations were much higher in fur than in muscle, and Hg concentrations in the 2 tissue types were weakly correlated. Abundant wind farms and ongoing postconstruction fatality surveys offer an underutilized opportunity to obtain tissue samples that can be used to assess Hg contamination in bats. Environ Toxicol Chem 2018;37:160-165. © 2018 SETAC. © 2017 SETAC.

Ecotoxicoparasitology: Understanding mercury concentrations in gut contents, intestinal helminths and host tissues of Alaskan gray wolves (Canis lupus)

Science.gov (United States)

McGrew, Ashley K.; O'Hara, Todd M.; Stricker, Craig A.; Castellini, Margaret; Beckmen, Kimberlee B.; Salman, Mo D.; Ballweber, Lora R.

2015-01-01

Some gastrointestinal helminths acquire nutrients from the lumen contents in which they live; thus, they may be exposed to non-essential elements, such as mercury (Hg), during feeding. The objectives of this study were: 1) determine the total mercury concentrations ([THg]) in Gray wolves (Canis lupus) and their parasites, and 2) use stable isotopes to evaluate the trophic relationships within the host. [THg] and stable isotopes (C and N) were determined for helminths, host tissues, and lumen contents from 88 wolves. Sixty-three wolves contained grossly visible helminths (71.5%). The prevalence of taeniids and ascarids was 63.6% (56/88) and 20.5% (18/88), respectively. Nine of these 63 wolves contained both taeniids and ascarids (14.3%). All ascarids were determined to beToxascaris leonina. Taenia species present included T. krabbei and T. hydatigena. Within the GI tract, [THg] in the lumen contents of the proximal small intestine were significantly lower than in the distal small intestine. There was a significant positive association between hepatic and taeniid [THg]. Bioaccumulation factors (BAF) ranged from < 1 to 22.9 in taeniids, and 1.1 to 12.3 in T. leonina. Taeniid and ascarid BAF were significantly higher than 1, suggesting that both groups are capable of THg accumulation in their wolf host. δ13C in taeniids was significantly lower than in host liver and skeletal muscle. [THg] in helminths and host tissues, in conjunction with stable isotope (C and N) values, provides insight into food-web dynamics of the host GI tract, and aids in elucidating ecotoxicoparasitologic relationships. Variation of [THg] throughout the GI tract, and between parasitic groups, underscores the need to further evaluate the effect(s) of feeding niche, and the nutritional needs of parasites, as they relate to toxicant exposure and distribution within the host.

Uptake and accumulation of mercury from dental amalgam in the common goldfish, Carassius auratus

International Nuclear Information System (INIS)

Kennedy, C.J.

2003-01-01

Exposure of fish to concentrations of dental amalgam typically found in waste discharge leads to mercury accumulation in tissues. - In this study, the bioavailability and accumulation of mercury from external environmental exposure to mixed, cured, milled, sieved and proportioned dental amalgam was examined in the common goldfish, Carassius auratus. Fish were exposed to dental amalgam (particle size range from <0.10 to 3.15 mm) in order to represent the particle size and distribution of that found within the typical dental office wastewater discharge stream. Experimental amalgam water loadings were 0 g/l, 0.5 g/l and 1 g/l in glass aquaria at 15 deg. C for 28 days. Fish tissues were sampled at 5 min and 28 days of exposure, and the liver, brain, muscle and whole body analyzed for total mercury using cold vapor atomic fluorescence spectroscopy. Mercury was found in several tissues examined and generally increased with exposure to higher amounts of dental amalgam. The highest levels were found in the whole body (17.68±5.73 μg/g) followed by the liver (0.80±0.16 μg/g) and muscle (0.47±0.16 μg/g). The lowest concentrations were seen in the brain (0.28±0.19 μg/g). Compared to controls, concentrations in the whole body, muscle and liver in fish exposed for 28 days to the highest concentration of amalgam were 200-, 233-, and 40-fold higher, respectively. This study shows that mercury from an environmental exposure to representative samples of dental amalgam typically found within the dental wastewater discharge stream is bioavailable to fish and may accumulate in internal tissues

Uptake and accumulation of mercury from dental amalgam in the common goldfish, Carassius auratus

Energy Technology Data Exchange (ETDEWEB)

Kennedy, C.J

2003-03-01

Exposure of fish to concentrations of dental amalgam typically found in waste discharge leads to mercury accumulation in tissues. - In this study, the bioavailability and accumulation of mercury from external environmental exposure to mixed, cured, milled, sieved and proportioned dental amalgam was examined in the common goldfish, Carassius auratus. Fish were exposed to dental amalgam (particle size range from <0.10 to 3.15 mm) in order to represent the particle size and distribution of that found within the typical dental office wastewater discharge stream. Experimental amalgam water loadings were 0 g/l, 0.5 g/l and 1 g/l in glass aquaria at 15 deg. C for 28 days. Fish tissues were sampled at 5 min and 28 days of exposure, and the liver, brain, muscle and whole body analyzed for total mercury using cold vapor atomic fluorescence spectroscopy. Mercury was found in several tissues examined and generally increased with exposure to higher amounts of dental amalgam. The highest levels were found in the whole body (17.68{+-}5.73 {mu}g/g) followed by the liver (0.80{+-}0.16 {mu}g/g) and muscle (0.47{+-}0.16 {mu}g/g). The lowest concentrations were seen in the brain (0.28{+-}0.19 {mu}g/g). Compared to controls, concentrations in the whole body, muscle and liver in fish exposed for 28 days to the highest concentration of amalgam were 200-, 233-, and 40-fold higher, respectively. This study shows that mercury from an environmental exposure to representative samples of dental amalgam typically found within the dental wastewater discharge stream is bioavailable to fish and may accumulate in internal tissues.

Flavobacterium branchiophilum and F. succinicans associated with bacterial gill disease in rainbow trout Oncorhynchus mykiss (Walbaum) in water recirculation aquaculture systems

Science.gov (United States)

Raised rainbow trout Oncorhynchus mykiss in six replicated water recirculation aquaculture systems (WRAS), and manipulated environmental conditions to promote bacterial gill disease (BGD). For each episode of BGD, gill tissue was sampling from affected fish, unaffected fish within the same WRAS, and...

Mercury

NARCIS (Netherlands)

de Vries, Irma

2017-01-01

Mercury is a naturally occurring metal that exists in several physical and chemical forms. Inorganic mercury refers to compounds formed after the combining of mercury with elements such as chlorine, sulfur, or oxygen. After combining with carbon by covalent linkage, the compounds formed are called

Fate of Tetracapsuloides bryosalmonae (Myxozoa) after infection of brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss

OpenAIRE

Kumar, Gokhlesh; Abd-Elfattah, Ahmed; Saleh, Mona; El-Matbouli, Mansour

2013-01-01

Tetracapsuloides bryosalmonae (Myxozoa) is the causative agent of proliferative kidney disease in salmonids. We assessed differences in intensity of T. bryosalmonae infection between brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss from the clinical phase of infection onwards. Specific pathogen-free fish were exposed to T. bryosalmonae spores under controlled laboratory conditions and sampled at 6, 8, 10, 12, 14, and 17 wk post exposure (wpe), and the transmission of T. bryosalm...

Experimental evaluation of rainbow trout Oncorhynchus mykiss predation on longnose dace Rhinichthys cataractae

Science.gov (United States)

Turek, Kelly C.; Pegg, Mark A.; Pope, Kevin L.

2014-01-01

Laboratory and in-stream enclosure experiments were used to determine whether rainbow trout Oncorhynchus mykiss influence survival of longnose dace Rhinichthys cataractae. In the laboratory, adult rainbow trout preyed on longnose dace in 42% of trials and juvenile rainbow trout did not prey on longnose dace during the first 6 h after rainbow trout introduction. Survival of longnose dace did not differ in the presence of adult rainbow trout previously exposed to active prey and those not previously exposed to active prey ( = 0.28, P = 0.60). In field enclosures, the number of longnose dace decreased at a faster rate in the presence of rainbow trout relative to controls within the first 72 h, but did not differ between moderate and high densities of rainbow trout (F2,258.9 = 3.73, P = 0.03). Additionally, longnose dace were found in 7% of rainbow trout stomachs after 72 h in enclosures. Rainbow trout acclimated to the stream for longer periods had a greater initial influence on the number of longnose dace remaining in enclosures relative to those acclimated for shorter periods regardless of rainbow trout density treatment (F4,148.5 = 2.50, P = 0.04). More research is needed to determine how predation rates will change in natural environments, under differing amounts of habitat and food resources and in the context of whole assemblages. However, if rainbow trout are introduced into the habitat of longnose dace, some predation on longnose dace is expected, even when rainbow trout have no previous experience with active prey.

Evaluation of the Life History of Native Salmonids in the Malheur River Basin; Cooperative Bull Trout/Redband Trout Research Project, 1999-2000 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Schwabe, Lawrence; Tiley, Mark (Burns Paiute Tribe, Department of Fish and Wildlife, Burns, OR); Perkins, Raymond R. (Oregon Department of Fish and Wildlife, Ontario, OR)

2000-11-01

The purpose of this study is to document the seasonal distribution of adult/sub-adult bull trout (Salvelinus confluentus) in the Malheur River basin. Due to the decline of bull trout in the Columbia Basin, the United States Fish and Wildlife Service listed bull trout as a threatened species in June 1998. Past land management activities; construction of dams; and fish eradication projects in the North Fork and Middle Fork Malheur River by poisoning have worked in concert to cumulatively impact native species in the Malheur Basin (Bowers et. al. 1993). Survival of the remaining bull trout populations is severely threatened (Buchanan 1997). 1999 Research Objects are: (1) Document the migratory patterns of adult/sub-adult bull trout in the North Fork Malheur River; (2) Determine the seasonal bull trout use of Beulah Reservoir and bull trout entrainment; and (3) Timing and location of bull trout spawning in the North Fork Malheur River basin. The study area includes the Malheur basin from the mouth of the Malheur River located near Ontario, Oregon to the headwaters of the North Fork Malheur River (Map 1). All fish collected and most of the telemetry effort was done on the North Fork Malheur River subbasin (Map 2). Fish collection was conducted on the North Fork Malheur River at the tailwaters of Beulah Reservoir (RK 29), Beulah Reservoir (RK 29-RK 33), and in the North Fork Malheur River at Crane Crossing (RK 69) to the headwaters of the North Fork Malheur. Radio telemetry was done from the mouth of the Malheur River in Ontario, Oregon to the headwaters of the North Fork Malheur. This report will reflect all migration data collected from 3/1/99 to 12/31/99.

Comparison of pigment cell ultrastructure and organisation in the dermis of marble trout and brown trout, and first description of erythrophore ultrastructure in salmonids.

Science.gov (United States)

Djurdjevič, Ida; Kreft, Mateja Erdani; Sušnik Bajec, Simona

2015-11-01

Skin pigmentation in animals is an important trait with many functions. The present study focused on two closely related salmonid species, marble trout (Salmo marmoratus) and brown trout (S. trutta), which display an uncommon labyrinthine (marble-like) and spot skin pattern, respectively. To determine the role of chromatophore type in the different formation of skin pigment patterns in the two species, the distribution and ultrastructure of chromatophores was examined with light microscopy and transmission electron microscopy. The presence of three types of chromatophores in trout skin was confirmed: melanophores; xanthophores; and iridophores. In addition, using correlative microscopy, erythrophore ultrastructure in salmonids was described for the first time. Two types of erythrophores are distinguished, both located exclusively in the skin of brown trout: type 1 in black spot skin sections similar to xanthophores; and type 2 with a unique ultrastructure, located only in red spot skin sections. Morphologically, the difference between the light and dark pigmentation of trout skin depends primarily on the position and density of melanophores, in the dark region covering other chromatophores, and in the light region with the iridophores and xanthophores usually exposed. With larger amounts of melanophores, absence of xanthophores and presence of erythrophores type 1 and type L iridophores in the black spot compared with the light regions and the presence of erythrophores type 2 in the red spot, a higher level of pigment cell organisation in the skin of brown trout compared with that of marble trout was demonstrated. Even though the skin regions with chromatophores were well defined, not all the chromatophores were in direct contact, either homophilically or heterophilically, with each other. In addition to short-range interactions, an important role of the cellular environment and long-range interactions between chromatophores in promoting adult pigment pattern

A Review of Mercury Exposure and Health of Dental Personnel

Directory of Open Access Journals (Sweden)

Natasha Nagpal

2017-03-01

Full Text Available Considerable effort has been made to address the issue of occupational health and environmental exposure to mercury. This review reports on the current literature of mercury exposure and health impacts on dental personnel. Citations were searched using four comprehensive electronic databases for articles published between 2002 and 2015. All original articles that evaluated an association between the use of dental amalgam and occupational mercury exposure in dental personnel were included. Fifteen publications from nine different countries met the selection criteria. The design and quality of the studies showed significant variation, particularly in the choice of biomarkers as an indicator of mercury exposure. In several countries, dental personnel had higher mercury levels in biological fluids and tissues than in control groups; some work practices increased mercury exposure but the exposure levels remained below recommended guidelines. Dental personnel reported more health conditions, often involving the central nervous system, than the control groups. Clinical symptoms reported by dental professionals may be associated with low-level, long-term exposure to occupational mercury, but may also be due to the effects of aging, occupational overuse, and stress. It is important that dental personnel, researchers, and educators continue to encourage and monitor good work practices by dental professionals.

Conservation of native Pacific trout diversity in western North America

Science.gov (United States)

Penaluna, Brooke E.; Abadía-Cardoso, Alicia; Dunham, Jason B.; García de León, Francisco J; Gresswell, Robert E.; Luna, Arturo Ruiz; Taylor, Eric B.; Shepard, Bradley B.; Al-Chokhachy, Robert K.; Muhlfeld, Clint C.; Bestgen, Kevin R.; Rogers, Kevin H.; Escalante, Marco A; Keeley, Ernest R; Temple, Gabriel; Williams, Jack E.; Matthews, Kathleen; Pierce, Ron; Mayden, Richard L.; Kovach, Ryan; Garza, John Carlos; Fausch, Kurt D.

2016-01-01

Pacific trout Oncorhynchus spp. in western North America are strongly valued in ecological, socioeconomic, and cultural views, and have been the subject of substantial research and conservation efforts. Despite this, the understanding of their evolutionary histories, overall diversity, and challenges to their conservation is incomplete. We review the state of knowledge on these important issues, focusing on Pacific trout in the genus Oncorhynchus. Although most research on salmonid fishes emphasizes Pacific salmon, we focus on Pacific trout because they share a common evolutionary history, and many taxa in western North America have not been formally described, particularly in the southern extent of their ranges. Research in recent decades has led to the revision of many hypotheses concerning the origin and diversification of Pacific trout throughout their range. Although there has been significant success at addressing past threats to Pacific trout, contemporary and future threats represented by nonnative species, land and water use activities, and climate change pose challenges and uncertainties. Ultimately, conservation of Pacific trout depends on how well these issues are understood and addressed, and on solutions that allow these species to coexist with a growing scope of human influences.

Cardiorespiratory upregulation during seawater acclimation in rainbow trout: effects on gastrointestinal perfusion and postprandial responses.

Science.gov (United States)

Brijs, Jeroen; Gräns, Albin; Ekström, Andreas; Olsson, Catharina; Axelsson, Michael; Sandblom, Erik

2016-05-01

Increased gastrointestinal blood flow is essential for euryhaline fishes to maintain osmotic homeostasis during the initial phase of a transition from freshwater to seawater. However, the cardiorespiratory responses and hemodynamic changes required for a successful long-term transition to seawater remain largely unknown. In the present study, we simultaneously measured oxygen consumption rate (ṀO2), cardiac output (CO), heart rate (HR), and gastrointestinal blood flow (GBF) in rainbow trout (Oncorhynchus mykiss) acclimated to either freshwater or seawater for at least 6 wk. Seawater-acclimated trout displayed significantly elevated ṀO2 (day: 18%, night: 19%), CO (day: 22%, night: 48%), and GBF (day: 96%, night: 147%), demonstrating that an overall cardiorespiratory upregulation occurs during seawater acclimation. The elevated GBF was achieved via a combination of increased CO, mediated through elevated stroke volume (SV), and a redistribution of blood flow to the gastrointestinal tract. Interestingly, virtually all of the increase in CO of seawater-acclimated trout was directed to the gastrointestinal tract. Although unfed seawater-acclimated trout displayed substantially elevated cardiorespiratory activity, the ingestion of a meal resulted in a similar specific dynamic action (SDA) and postprandial GBF response as in freshwater-acclimated fish. This indicates that the capacity for the transportation of absorbed nutrients, gastrointestinal tissue oxygen delivery, and acid-base regulation is maintained during digestion in seawater. The novel findings presented in this study clearly demonstrate that euryhaline fish upregulate cardiovascular function when in seawater, while retaining sufficient capacity for the metabolic and cardiovascular changes associated with the postprandial response. Copyright © 2016 the American Physiological Society.

Across the great divide: genetic forensics reveals misidentification of endangered cutthroat trout populations.

Science.gov (United States)

Metcalf, Jessica L; Pritchard, Victoria L; Silvestri, Sarah M; Jenkins, Jazzmin B; Wood, John S; Cowley, David E; Evans, R Paul; Shiozawa, Dennis K; Martin, Andrew P

2007-11-01

Accurate assessment of species identity is fundamental for conservation biology. Using molecular markers from the mitochondrial and nuclear genomes, we discovered that many putatively native populations of greenback cutthroat trout (Oncorhynchus clarkii stomias) comprised another subspecies of cutthroat trout, Colorado River cutthroat trout (Oncorhynchus clarkii pleuriticus). The error can be explained by the introduction of Colorado River cutthroat trout throughout the native range of greenback cutthroat trout in the late 19th and early 20th centuries by fish stocking activities. Our results suggest greenback cutthroat trout within its native range is at a higher risk of extinction than ever before despite conservation activities spanning more than two decades.

Using Sulfate-Amended Sediment Slurry Batch Reactors to Evaluate Mercury Methylation

International Nuclear Information System (INIS)

Harmon, S.M.

2003-01-01

In the methylated form, mercury represents a concern to public health primarily through the consumption of contaminated fish tissue. Research conducted on the methylation of mercury strongly suggests the process is microbial in nature and facilitated principally by sulfate-reducing bacteria. This study addressed the potential for mercury methylation by varying sulfate treatments and wetland-based soil in microbial slurry reactors with available inorganic mercury. Under anoxic laboratory conditions conducive to growth of naturally occurring sulfate-reducing bacteria in the soil, it was possible to evaluate how various sulfate additions influenced the methylation of inorganic mercury added to overlying water. Treatments included sulfate amendments ranging FR-om 25 to 500 mg/L (0.26 to 5.2 mM) above the soil's natural sulfate level. This study also provided an assessment of mercury methylation relative to sulfate-reducing bacterial population growth and subsequent sulfide production. Mercury methylation in sulfate treatments did not exceed that of the non-amended control during a 35-day incubation. However, increases in methylmercury concentration were linked to bacterial growth and sulfate reduction. A time lag in methylation in the highest treatment correlated with an equivalent lag in bacterial growth

Otter ( Lutra lutra ) predation on stocked brown trout ( Salmo trutta ) in two Danish lowland rivers

DEFF Research Database (Denmark)

Jacobsen, Lene

2005-01-01

This study aimed to evaluate otter predation on stocked trout. Large hatchery-reared trout (16-30 cm) were stocked into two Danish rivers with different fish populations. Otter diet before and after trout stocking was determined by analysing 685 spraints, collected regularly during the 35-day study...... period. Fish composition in the rivers before stocking was assessed by electrofishing. In River Trend, a typical trout river, the proportion of trout in the otter diet increased from 8% before stocking to 33% a few days after stocking. Moreover, trout lengths in the diet changed significantly towards...... the lengths of stocked trout, indicating that newly stocked trout were preferred to wild trout. In River Skals, dominated by cyprinids, there was no change in otter diet after stocking of hatchery trout, i.e., these were ignored by otter. Otter predation should be taken into account together with fish...

Bull trout population assessment in the Columbia River Gorge/annual report fy2000; ANNUAL

International Nuclear Information System (INIS)

Byrne, Jim; McPeak, Ron

2001-01-01

We summarized existing knowledge regarding the known distribution of bull trout (Salvelinus confluentus) across four sub-basins in the Columbia River Gorge in Washington. The Wind River, Little White Salmon River, White Salmon River, and the Klickitat River sub-basins were analyzed. Cold water is essential to the survival, spawning, and rearing of bull trout. We analyzed existing temperature data, installed Onset temperature loggers in the areas of the four sub-basins where data was not available, and determined that mean daily water temperatures were and lt;15 C and appropriate for spawning and rearing of bull trout. We snorkel surveyed more than 74 km (46.25 mi.) of rivers and streams in the four sub-basins (13.8 km at night and 60.2 km during the day) and found that night snorkeling was superior to day snorkeling for locating bull trout. Surveys incorporated the Draft Interim Protocol for Determining Bull Trout Presence (Peterson et al. In Press). However, due to access and safety issues, we were unable to randomly select sample sites nor use block nets as recommended. Additionally, we also implemented the Bull Trout/Dolly Varden sampling methodology described in Bonar et al. (1997). No bull trout were found in the Wind River, Little White Salmon, or White Salmon River sub-basins. We found bull trout in the West Fork Klickitat drainage of the Klickitat River Sub-basin. Bull trout averaged 6.7 fish/100m(sup 2) in Trappers Creek, 2.6 fish/100m(sup 2) on Clearwater Creek, and 0.4 fish/100m(sup 2) in Little Muddy Creek. Bull trout was the only species of salmonid encountered in Trappers Creek and dominated in Clearwater Creek. Little Muddy Creek was the only creek where bull trout and introduced brook trout occurred together. We found bull trout only at night and typically in low flow regimes. A single fish, believed to be a bull trout x brook trout hybrid, was observed in the Little Muddy Creek. Additional surveys are needed in the West Fork Klickitat and mainstem

Summary of the Skookumchuck Creek bull trout enumeration project 2001.; TOPICAL

International Nuclear Information System (INIS)

Baxter, James S.; Baxter, Jeremy

2002-01-01

This report summarizes the second year of a bull trout (Salvelinus confluentus) enumeration project on Skookumchuck Creek in southeastern British Columbia. An enumeration fence and traps were installed on the creek from September 6th to October 12th 2001 to enable the capture of post-spawning bull trout emigrating out of the watershed. During the study period, a total of 273 bull trout were sampled through the enumeration fence. Length and weight were determined for all bull trout captured. In total, 39 fish of undetermined sex, 61 males and 173 females were processed through the fence. An additional 19 bull trout were observed on a snorkel survey prior to the fence being removed on October 12th. Coupled with the fence count, the total bull trout enumerated during this project was 292 fish. Several other species of fish were captured at the enumeration fence including westslope cutthroat trout (Oncorhynchus clarki lewisi), Rocky Mountain whitefish (Prosopium williamsoni), and kokanee (O. nerka). A total of 143 bull trout redds were enumerated on the ground in two different locations (river km 27.5-30.5, and km 24.0-25.5) on October 3rd. The majority of redds (n=132) were observed in the 3.0 km index section (river km 27.5-30.5) that has been surveyed over the past five years. The additional 11 redds were observed in a 1.5 km section (river km 24.0-25.5). Summary plots of water temperature for Bradford Creek, Sandown Creek, Buhl Creek, and Skookumchuck Creek at three locations suggested that water temperatures were within the temperature range preferred by bull trout for spawning, egg incubation, and rearing

Effect of potassium ethylxanthate and sodium diethyldithiocarbamate on the accumulation and disposition of nickel in the brown trout (salmo trutta)

International Nuclear Information System (INIS)

Gottofrey, J.; Borg, K.; Jasim, S.; Tjaelve, H.

1988-01-01

Brown trouts, Salmo trutta, were exposed to water containing 0.1 or 10 μg/1 of 63 Ni 2+ , alone or with potassium ethylxanthate or sodium diethyldithiocarbamate. After one and three weeks the accumulation and disposition of the 63 Ni 2+ in the fish were examined by liquid scintillation spectrometry and whole-body autoradiography. The sodium diethyldithiocarbamate was found to greatly enhance the uptake of 63 Ni 2+ in several tissues of the trouts. Potassium ethylxanthate was without effect. Diethyldithiocarbamate is known to form lipophilic complexes with metals, including nickel, and a facilitated penetration of the complexed nickel over the cellular membranes of the gills and other tissues is a likely mechanism underlying our results. The ethylxanthate is also able to form a lipophilic nickel-chelate, although of a lower lipophilicity than the nickel-diethyldithiocarbamate-complex. This variance in lipophilicity may explain why the disposition of the 63 Ni 2+ was affected by the diethyldithiocarbamate, but not by the ethylxanthate. (author)

The effect of the combined feed "Aller Aqua" on the content of free amino acids in the muscles and liver of brown (Salmo trutta Linnaeus, 1758 and rainbow (Oncorhynchus mykiss Walbaum, 1792 trout

Directory of Open Access Journals (Sweden)

L. Galoyan

2017-12-01

Full Text Available Purpose. To study the level of amino acid assimilation from the protein of the combined feed and also to characterize the amino acid composition of proteins in muscles and liver of the brown and rainbow trout in conditions of feeding them with the specialized production combined feed manufactured by Aller Aqua. Methodology. The total amino acid composition of muscle and liver tissues was determined by ion-exchange liquid column chromatography. Findings. The amino acid composition of the investigated feed as a whole corresponds to the spectrum of amino acids in the tissues of muscles and liver of the brown and rainbow trout. Both a significant predominance of glutamine and glutamic acid was detected in the liver and in the muscles of fish. Among the essential amino acids in the muscles and liver of the fish studied, the largest share belongs to leucine, arginine and lysine. Originality. First investigated the effect of artificial feeding with specialized productional fodder «Aller Aqua» on the amino acid composition of tissues of brown and rainbow trout reared in conditions of industrial aquaculture. Practical value. Currently, studies devoted to a comprehensive assessment of the effect of mixed feeds on growth and development, and in particular on the amino acid composition of salmon fish tissues, acquire particular attention. This work makes it possible to investigate the degree of assimilation of protein components of the artificial feed for rainbow trout and discuss the perspectives of the adjustment of the imbalance and deficiency of amino acid composition in the feed.

Detection of Flavobacterium psychrophilum from fish tissue and water samples by PCR amplification

DEFF Research Database (Denmark)

Wiklund, T.; Madsen, Lone; Bruun, Morten Sichlau

2000-01-01

investigation, the possible detection of Fl. psychrophilum from fish tissue and water samples was examined using nested PCR with DNA probes against a sequence of the 16S rRNA genes. The DNA was extracted using Chelex(R) 100 chelating resin. The primers, which were tested against strains isolated from diseased...... fish, healthy fish, fish farm environments and reference strains, proved to be specific for Fl. psychrophilum. The obtained detection limit of Fl. psychrophilum seeded into rainbow trout brain tissue was 0.4 cfu in the PCR tube, corresponding to 17 cfu mg(-1) brain tissue. The PCR-assay proved...... to be more sensitive than agar cultivation of tissue samples from the brain of rainbow trout injected with Fl. psychrophilum. In non-sterile fresh water seeded with Fl. psychrophilum the detection limit of the PCR- assay was 1.7 cfu in the PCR tube, corresponding to 110 cfu ml(-1) water. The PCR...

Monitoring mercury in freshwater fish in the oil sands region of Northern Alberta : spatial and temporal comparisons to regional mercury concentrations in fish

International Nuclear Information System (INIS)

Keith, H.

2010-01-01

The Regional Aquatics Monitoring Program (RAMP) was launched to provide a better understanding of the potential effects of oil sands development on aquatic systems, and to address issues important to communities of northern Alberta, such as mercury concentrations in fish. Muskeg dewatering, deforestation, flooding, and air emissions are among the potential mercury sources entering the aquatic systems within the oil sands region. RAMP collects non-lethal tissue samples on an annual basis for mercury analysis from northern pike (Esox lucius), walleye (Sander vitreus), and lake whitefish (Coregonus clupeaformis) in various rivers and lakes within the oil sands region. The purpose is to evaluate the suitability of fisheries resources for human consumption and to evaluate the potential cumulative biological effects on fish. A mercury database was developed based on studies in other regions in Alberta and across Canada in order to provide a regional context to the RAMP monitoring results. Data points from 1975 to 2009 were mapped to evaluate spatial and temporal differences in mercury concentrations and any exceedances of subsistence and general consumption guidelines. This monitoring effort has been instrumental in determining whether changes in mercury concentrations in fish are localized to a specific waterbody or regional in nature.

49 CFR 173.164 - Mercury (metallic and articles containing mercury).

Science.gov (United States)

2010-10-01

... ounces) of mercury per package; (iv) Tubes which are completely jacketed in sealed leakproof metal cases... 49 Transportation 2 2010-10-01 2010-10-01 false Mercury (metallic and articles containing mercury... Than Class 1 and Class 7 § 173.164 Mercury (metallic and articles containing mercury). (a) For...

Monitor and Protect Wigwam River Bull Trout for Koocanusa Reservoir; Skookumchuck Creek Juvenile Bull Trout and Fish Habitat Monitoring Program, Annual Report 2002.

Energy Technology Data Exchange (ETDEWEB)

Cope, R.

2003-06-01

The Skookumchuck Creek juvenile bull trout (Salvelinus confluentus) and fish habitat-monitoring program is a co-operative initiative of the British Columbia Ministry of Water, Land, and Air Protection and Bonneville Power Administration. This project was commissioned in planning for fish habitat protection and forest development within the Skookumchuck Creek watershed and was intended to expand upon similar studies initiated within the Wigwam River from 2000 to 2002. The broad intent is to develop a better understanding of juvenile bull trout and Westslope cutthroat trout recruitment and the ongoing hydrologic and morphologic processes, especially as they relate to spawning and rearing habitat quality. The 2002 project year represents the first year of a long-term bull trout-monitoring program with current studies focused on collecting baseline information. This report provides a summary of results obtained to date. Bull trout represented 72.4% of the catch. Fry dominated the catch because site selection was biased towards electrofishing sample sites which favored high bull trout fry capture success. The mean density of all juvenile bull trout was estimated to be 6.6 fish/100m{sup 2}. This represents one-half the densities reported for the 2002 Wigwam River enumeration program, even though enumeration of bull trout redds was an order of magnitude higher for the Wigwam River. Typically, areas with combined fry and juvenile densities greater than 1.5 fish per 100 m{sup 2} are cited as critical rearing areas. Trends in abundance appeared to be related to proximity to spawning areas, bed material size, and water depth. Cover components utilized by juvenile and adult bull trout and cutthroat trout were interstices, boulder, depth, overhead vegetation and LWD. The range of morphological stream types encompass the stable and resilient spectrum (C3(1), C3 and B3c). The Skookumchuck can be generalized as a slightly entrenched, meandering, riffle-pool, cobble dominated

Kinetic Behaviour of Glucose 6-Phosphate Dehydrogenase and 6-Phosphogluconate Dehydrogenase in Different Tissues of Rainbow Trout (Oncorhynchus mykiss Exposed to Non-Lethal Concentrations of Cadmium

Directory of Open Access Journals (Sweden)

Olcay Hisar

2009-01-01

Full Text Available The effects of cadmium (Cd on the enzymatic activities of glucose 6-phosphate dehydrogenase (G6PD and 6-phosphogluconate dehydrogenase (6PGD were investigated in the gill, liver and kidney tissues of rainbow trout (Oncorhynchus mykiss. Three test groups of fish were subjected to increasing concentrations (1, 3 and 5 mg/l of cadmium (Cd in vivo, respectively. The G6PD and 6PGD activities in the gill, liver, and kidney tissues of each group of fish were measured on days 1, 3, 5 and 7. G6PD and 6PGD enzyme activities, measured in gill, liver and kidney homogenates, were stimulated by various concentrations (1, 3, and 5 mg/l of cadmium. Although the dose-response pattern of G6PD enzyme activities in liver and kidney tissue was very similar, that in gill was different from both other tissues. The enzyme activity of G6PD enzyme was significantly stimulated after three days (Day 3 in liver and kidney tissues at a dose of 1 mg/l Cd (p p p p p p < 0.05 in liver and kidney tissues at the doses of 3 and 1 mg/l Cd. The stimulation effect of cadmium on the three tissues studied was also calculated; for both of the enzymes (G6PD and 6PGD, the enzyme activity levels were stimulated by approximately 60% and 38% in gills, 68% and 44% in liver, and 67% and 41% in kidneys, respectively, over the base-line enzyme activity of the control groups during the sevenday experimental period. These findings indicate that tissue G6PD and 6PGD enzymes function to protect against cadmium toxicity.

Effect of ellagic acid on some haematological, immunological and antioxidant parameters of rainbow trout (Oncorhynchus mykiss).

Science.gov (United States)

Mişe Yonar, S; Yonar, M E; Yöntürk, Y; Pala, A

2014-10-01

In this study, effect of ellagic acid on some haematological, immunological and antioxidant parameters in the blood and various tissues of rainbow trout (Oncorhynchus mykiss) were examined. Four groups of rainbow trout were fed experimental diets containing either no ellagic acid (control) or supplemented with ellagic acid at 50 mg/kg diet (EA-50), 100 mg/kg diet (EA-100) or 150 mg/kg diet (EA-150) for 21 days. Samples of the blood and tissue (liver, kidney and spleen) were collected at the end of the experiment and analysed for their haematological profile (the red blood cell count, the haemoglobin concentration and the haematocrit level), immune response (the white blood cell count, the oxidative radical production (NBT activity), the total plasma protein and total immunoglobulin level) and oxidant/antioxidant status (the malondialdehyde level, the superoxide dismutase, catalase and glutathione peroxidase activity as well as the reduced glutathione concentration). The findings of this study demonstrated that ellagic acid had a positive effect on the haematological parameters, the immune response and the antioxidant enzyme activities of the fish. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

Stream pH as an abiotic gradient influencing distributions of trout in Pennsylvania streams

Science.gov (United States)

Kocovsky, P.M.; Carline, R.F.

2005-01-01

Elevation and stream slope are abiotic gradients that limit upstream distributions of brook trout Salvelinus fontinalis and brown trout Salmo trutta in streams. We sought to determine whether another abiotic gradient, base-flow pH, may also affect distributions of these two species in eastern North America streams. We used historical data from the Pennsylvania Fish and Boat Commission's fisheries management database to explore the effects of reach elevation, slope, and base-flow pH on distributional limits to brook trout and brown trout in Pennsylvania streams in the Appalachian Plateaus and Ridge and Valley physiographic provinces. Discriminant function analysis (DFA) was used to calculate a canonical axis that separated allopatric brook trout populations from allopatric brown trout populations and allowed us to assess which of the three independent variables were important gradients along which communities graded from allopatric brook trout to allopatric brown trout. Canonical structure coefficients from DFA indicated that in both physiographic provinces, stream base-flow pH and slope were important factors in distributional limits; elevation was also an important factor in the Ridge and Valley Province but not the Appalachian Plateaus Province. Graphs of each variable against the proportion of brook trout in a community also identified apparent zones of allopatry for both species on the basis of pH and stream slope. We hypothesize that pH-mediated interspecific competition that favors brook trout in competition with brown trout at lower pH is the most plausible mechanism for segregation of these two species along pH gradients. Our discovery that trout distributions in Pennsylvania are related to stream base-flow pH has important implications for brook trout conservation in acidified regions. Carefully designed laboratory and field studies will be required to test our hypothesis and elucidate the mechanisms responsible for the partitioning of brook trout and

Trout Stream Special Regulations

Data.gov (United States)

Minnesota Department of Natural Resources — This layer shows Minnesota trout streams that have a special regulation as described in the 2006 Minnesota Fishing Regulations. Road crossings were determined using...

Recovery of mercury from mercury compounds via electrolytic methods

Science.gov (United States)

Grossman, Mark W.; George, William A.

1988-01-01

A process for electrolytically recovering mercury from mercury compounds is provided. In one embodiment, Hg is recovered from Hg.sub.2 Cl.sub.2 employing as the electrolyte solution a mixture of HCl and H.sub.2 O. In another embodiment, Hg is electrolytically recovered from HgO wherein the electrolyte solution is comprised of glacial acetic acid and H.sub.2 O. Also provided is an apparatus for producing isotopically enriched mercury compounds in a reactor and then transporting the dissolved compounds into an electrolytic cell where mercury ions are electrolytically reduced and elemental mercury recovered from the mercury compounds.

Medico legal aspects of self-injection of metallic mercury in cases of suicide or self-harming.

Science.gov (United States)

Da Broi, Ugo; Moreschi, Carlo; Colatutto, Antonio; Marcon, Barbara; Zago, Silvia

2017-08-01

Metallic mercury may be self-injected for suicidal or self-harm purposes or sometimes for superstitious or other inadvisable reasons. Local tissue or systemic consequences such as mercurialism can frequently occur in cases of subcutaneous or deep injection, while death due to pulmonary embolism and cardiac, brain, hepatic or renal toxicity may occur in cases of high dosage intravenous administration. The aim of this review is to focus on the diagnostic difficulties facing coroners and forensic pathologists when the courts require confirmation that evidence of self-injection of metallic mercury is the result of suicide or self-harming. Forensic examination performed on the corpses of victims who died in or out of hospital or on surviving injured or intoxicated victims showing signs of mercurialism, demands the careful evaluation of the death scene, of all related circumstances and of the clinical and autopsy data. Close interaction between forensic pathologists and toxicologists is also needed to identify and quantify mercury levels in blood, urine and tissue. Copyright © 2017 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Effect of storage on residue levels of enrofloxacin in muscle of rainbow trout (Oncorhynchus mykiss and common carp (Cyprinus carpio

Directory of Open Access Journals (Sweden)

Ralica Kyuchukova

2016-03-01

Full Text Available Since fluoroquinolones are one of the most commonly used antibacterial drugs in aquaculture, there is a risk of their residues to be found in the treated fish. The objective of this study was to examine t he changes in enrofloxacin and ciprofloxacin levelsduring storage of rainbow trout and common carp muscle at -18 °C. The trout and carp were treated orally with a single dose of 10 mg/kg of enrofloxacin. Tissue samples were collected 24 h after the treatment and stored at -18 °C for 270 days either as a whole fish or as precut muscle samples. Results for trout revealed that in the precut samples enrofloxacin concentration decreased significantly only after 9 months of storage, whereas a significant decline in the ciprofloxacin level was observed much earlier (after 3 months. After 9 months of storage, the trout stored without being sliced and eviscerated showed significantly higher levels of both quinolones as compared to the precut muscle samples. The enrofloxacin levels in the carp musculature decreased considerably after 3 months of storage and stayed almost unchanged up to the end of the study, whereas the ciprofloxacin concentration continued to drop even after this period and after 270 days constituted 1/6 of the initial values.

Polychlorinated biphenyl reduction in lake trout by irradiation and broiling

International Nuclear Information System (INIS)

Cichy, R.F.; Zabik, M.E.; Weaver, C.M.

1979-01-01

The Great Lakes Environmental contaminants surveys (1974-1975) have concluded that excessive concentrations of polychlorinated biphenyls (PCBs) are present in a specific species of lake trout (Salvelinus namaycush). Over 30 ppM of PCBs have been detected in the edible fillet of this fat trout. The objective of this study was to determine the effect of gamma irradiation combined with broiling on the levels of PCBs in lake trout fillets

Locus ceruleus neurons in people with autism contain no histochemically-detectable mercury.

Science.gov (United States)

Pamphlett, Roger; Kum Jew, Stephen

2016-02-01

Exposure to environmental mercury has been proposed to play a part in autism. Mercury is selectively taken up by the human locus ceruleus, a region of the brain that has been implicated in autism. We therefore looked for the presence of mercury in the locus ceruleus of people who had autism, using the histochemical technique of autometallography which can detect nanogram amounts of mercury in tissues. In addition, we sought evidence of damage to locus ceruleus neurons in autism by immunostaining for hyperphosphorylated tau. No mercury was found in any neurons of the locus ceruleus of 6 individuals with autism (5 male, 1 female, age range 16-48 years). Mercury was present in locus ceruleus neurons in 7 of 11 (64%) age-matched control individuals who did not have autism, which is significantly more than in individuals with autism. No increase in numbers of locus ceruleus neurons containing hyperphosphorylated tau was detected in people with autism. In conclusion, most people with autism have not been exposed early in life to quantities of mercury large enough to be found later in adult locus ceruleus neurons. Human locus ceruleus neurons are sensitive indicators of mercury exposure, and mercury appears to remain in these neurons indefinitely, so these findings do not support the hypothesis that mercury neurotoxicity plays a role in autism.

Zooplankton size selection relative to gill raker spacing in rainbow trout

Science.gov (United States)

Budy, P.; Haddix, T.; Schneidervin, R.

2005-01-01

Rainbow trout Oncorhynchus mykiss are one of the most widely stocked salmonids worldwide, often based on the assumption that they will effectively utilize abundant invertebrate food resources. We evaluated the potential for feeding morphology to affect prey selection by rainbow trout using a combination of laboratory feeding experiments and field observations in Flaming Gorge Reservoir, Utah-Wyoming. For rainbow trout collected from the reservoir, inter-gill raker spacing averaged 1.09 mm and there was low variation among fish overall (SD = 0.28). Ninety-seven percent of all zooplankton observed in the diets of rainbow trout collected in the reservoir were larger than the interraker spacing, while only 29% of the zooplankton found in the environment were larger than the interraker spacing. Over the size range of rainbow trout evaluated here (200-475 mm), interraker spacing increased moderately with increasing fish length; however, the size of zooplankton found in the diet did not increase with increasing fish length. In laboratory experiments, rainbow trout consumed the largest zooplankton available; the mean size of zooplankton observed in the diets was significantly larger than the mean size of zooplankton available. Electivity indices for both laboratory and field observations indicated strong selection for larger-sized zooplankton. The size threshold at which electivity switched from selection against smaller-sized zooplankton to selection for larger-sized zooplankton closely corresponded to the mean interraker spacing for both groups (???1-1.2 mm). The combination of results observed here indicates that rainbow trout morphology limits the retention of different-sized zooplankton prey and reinforces the importance of understanding how effectively rainbow trout can utilize the type and sizes of different prey available in a given system. These considerations may improve our ability to predict the potential for growth and survival of rainbow trout within and

Wild Boar Tissue Levels of Cadmium, Lead and Mercury in Seven Regions of Continental Croatia

Science.gov (United States)

Sedak, Marija; Đokić, Maja; Šimić, Branimir

2010-01-01

Concentrations of cadmium, mercury and lead were analysed by atomic absorption spectrometry in the kidney and muscle of free-living wild boar (n = 169) from hunting grounds in seven counties of continental Croatia. Mean levels of metals (mg/kg) in muscle and kidney of boars ranged as follows: Cd: 0.005–0.016 and 0.866–4.58, Pb: 0.033–0.15 and 0.036–0.441, Hg: 0.004–0.012 and 0.04–0.152. In all seven regions, concentrations exceeded the permitted values (muscle and kidney mg/kg: cadmium 0.05/1; lead 0.1/0.5; mercury 0.03/0.1) in 13.6% and 71.6% of samples (muscle and kidney, respectively) for cadmium; 13.6% and 8.9% for lead; 19.5% and 2.4% for mercury. There were significant differences among the regions. Vukovar-Srijem and Virovitica-Podravina Counties were highly contaminated with cadmium, Sisak-Moslavina and Virovitica-Podravina Counties with lead and Brod-Posavina County had highest mercury concentrations. These results suggest a detailed investigation of physiological and environmental factors contributing to accumulation of metals in boars. PMID:20405101

Four CISH paralogues are present in rainbow trout Oncorhynchus mykiss: differential expression and modulation during immune responses and development.

Science.gov (United States)

Maehr, Tanja; Vecino, Jose L González; Wadsworth, Simon; Wang, Tiehui; Secombes, Christopher J

2014-11-01

Suppressor of cytokine signalling (SOCS) family members are crucial in the control and attenuation of cytokine induced responses via activation of the JAK/STAT, TLR and NF-kB signalling pathways. SOCS proteins orchestrate the termination of many types of immune responses and are often the targets of microbial pathogens exploiting SOCS mechanisms to evade the host's immune response. Through whole and lineage specific genome duplication events, the teleost cytokine/SOCS network is complex. Not only are the orthologues of all mammalian SOCS members present, namely cytokine inducible Src homology 2 (SH2)-containing protein (CISH) and SOCS-1 to -7, but multiple gene copies exist that may potentially become functionally divergent. In this paper we focus on the CISH genes in rainbow trout (Oncorhynchus mykiss), and have cloned two further paralogues, CISHa2 and CISHb2, additional to the known CISHa1 and CISHb1 genes. We present for the first time a comparative expression analysis of these four paralogues, to establish whether subfunctionalisation is apparent. In vivo examination of gene expression revealed a higher constitutive expression level of CISHa paralogues compared to CISHb expression in adult trout tissues. All CISHs were relatively highly abundant in immune tissues but CISHa2 and CISHb2 had highest expression in the heart and muscle. An inverse picture of CISH abundance during trout ontogeny was seen, and further hints at differential roles of the four genes in immune regulation and development. Stimulation of head kidney (HK) leukocytes with trout recombinant interleukin (rIL)-15 and rIL-21 had a major effect on CISHa2 and to a lesser extent CISHa1 expression. In HK macrophages rIL-1β, phytohemagglutinin, and phorbol 12-myristate 13-acetate also had a strong impact on CISHa2 expression. Yersinia ruckeri infection caused a temporally and spatially differential onset of CISH expression that may be viewed in the context of pathogen evasion strategies. These data

Cannibalism in non-native brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss stream-dwelling populations.

Science.gov (United States)

Musseau, C; Vincenzi, S; Jesenšek, D; Crivelli, A J

2017-12-01

Introduced and allopatric populations of brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss were sampled in Slovenia for stable isotope analysis to assess dietary niche shifts through ontogeny and estimate the propensity for cannibalism. Both S. trutta and O. mykiss are cannibals, with higher average relative contribution of conspecific assimilated energy for S. trutta (27·9%) compared with O. mykiss (7·7%). The smallest cannibal was 166 mm in the S. trutta population and 247 mm in the O. mykiss population. © 2017 The Fisheries Society of the British Isles.

Estimating the long-term effects of stocking domesticated trout into wild brown trout ( Salmo trutta ) populations : an approach using microsatellite DNA analysis of historical and contemporary samples

DEFF Research Database (Denmark)

Hansen, Michael Møller

2002-01-01

. The study was based on analysis of two historical samples (194556), represented by old scale collections, and seven contemporary samples (1986-2000). In one population historical and contemporary samples were remarkably genetically similar despite more than a decade of intense stocking. Estimation...... of admixture proportions showed a small genetic contribution from domesticated trout (approximately 6%), and individual admixture analysis demonstrated a majority of nonadmixed individuals. The expected genetic contribution by domesticated trout was 64%, assessed from the number of stocked trout and assuming...... in samples from a broodstock thought to represent the indigenous population and in a sample of wild spawners. Survival of domesticated trout and admixture with indigenous fish in the broodstock and subsequent stocking into the river, combined with a low population size of native trout relative to the number...

Immunity to VHS virus in rainbow trout

DEFF Research Database (Denmark)

Lorenzen, Niels; Olesen, Niels Jørgen; Koch, C.

1999-01-01

Viral hemorrhagic septicemia virus (VHSV) is the rhabdovirus that causes most disease problems in farmed rainbow trout in Europe. Survivors of infection are usually immune to reinfection but as with other fish viruses, development of a modern recombinant vaccine has been complicated by the limited...... knowledge of the immune mechanisms and antigens involved in induction of immunity. Neutralizing and protective monoclonal antibodies recognize the envelope glycoprotein (G protein) which is the only viral protein known to be present on the surface of the virus particle. Immunoblotting analyses...... with monoclonal antibodies as well as with sera from immunized trout have indicated that protein conformation plays an important role in neutralization epitopes. The virus neutralizing activity often found in sera from convalescent trout is highly dependent on a poorly defined complementing activity in normal...

Growth of brown trout in acid and alkaline waters

Energy Technology Data Exchange (ETDEWEB)

Campbell, R N

1961-01-01

Studies have been performed to determine the factors affecting the growth and maturity of brown trout in lochs in the Highlands of Scotland. Evidence has been found which supports the view that the growth rate depends more on the relation between the trout population and the food supply than on any direct influence of the chemical composition of the water. Details are given of the growth rate of trout in nine lochs with a wide range of alkalinities where spawning facilities are either very good or poor or non-existent.

Ultrastructural effects of pharmaceuticals (carbamazepine, clofibric acid, metoprolol, diclofenac) in rainbow trout (Oncorhynchus mykiss) and common carp (Cyprinus carpio).

Science.gov (United States)

Triebskorn, R; Casper, H; Scheil, V; Schwaiger, J

2007-02-01

In order to assess potential effects of human pharmaceuticals in aquatic wildlife, laboratory experiments were conducted with carbamazepine, clofibric acid, metoprolol, and diclofenac using fish as test organisms. For each substance, at least one environmentally relevant concentration was tested. In liver, kidney, and gills of trout and carp exposed to carbamazepine, clofibric acid, and metoprolol, ultrastructural effects were qualitatively described and semi-quantitatively assessed. The obtained assessment values were compared with previously published data for diclofenac-induced effects in rainbow trout tissues. Quantitative analyses of protein accumulated in kidneys of diclofenac-exposed trout corroborated previously published data which indicated that diclofenac induced a severe glomerulonephritis resulting in a hyaline droplet degeneration of proximal kidney tubules. The investigations provided information on the general health status of the pharmaceutical-exposed fish, and allowed a differential diagnosis of harmful effects caused by these human pharmaceuticals in non-target species. For the different cytological effects observed, lowest observed effect concentration (LOECs) for at least three of the test substances (diclofenac, carbamazepine, metoprolol) were in the range of environmentally relevant concentrations (1 microg/L).

Regulation of proliferation and differentiation of adipocyte precursor cells in rainbow trout (Oncorhynchus mykiss).

Science.gov (United States)

Bouraoui, L; Gutiérrez, J; Navarro, I

2008-09-01

Here, we describe optimal conditions for the culture of rainbow trout (Oncorhynchus mykiss) pre-adipocytes obtained from adipose tissue and their differentiation into mature adipocytes, in order to study the endocrine control of adipogenesis. Pre-adipocytes were isolated by collagenase digestion and cultured on laminin or 1% gelatin substrate. The expression of proliferating cell nuclear antigen was used as a marker of cell proliferation on various days of culture. Insulin growth factor-I stimulated cell proliferation especially on days 5 and 7 of culture. Tumor necrosis factor alpha (TNFalpha) slightly enhanced cell proliferation only at a low dose. We verified the differentiation of cells grown in specific medium into mature adipocytes by oil red O (ORO) staining. Quantification of ORO showed an increase in triglycerides throughout culture. Immunofluorescence staining of cells at day 11 revealed the expression of CCAAT/enhancer-binding protein and peroxisome proliferator-activator receptor gamma, suggesting that these transcriptional factors are involved in adipocyte differentiation in trout. We also examined the effect of TNFalpha on the differentiation of these adipocytes in primary culture. TNFalpha inhibited the differentiation of these cells, as indicated by a decrease in glycerol-3-phosphate dehydrogenase activity, an established marker of adipocyte differentiation. In conclusion, the culture system described here for trout pre-adipocytes is a powerful tool to study the endocrine regulation of adipogenesis in this species.

Binary mixtures of mercury/ selenium, and lead/selenium

African Journals Online (AJOL)

Physiologically-based biokinetic models have been developed for predicting simultaneously the Absorption, Distribution, Metabolism and Elimination (ADME) properties of lead (Pb) and selenium (Se), and mercury (Hg) and selenium in a number of target tissues of humans. This was done for three population groups, ...

Spatial and temporal consumption dynamics of trout in catch-and-release areas in Arkansas tailwaters

Science.gov (United States)

Flinders, John M.; Magoulick, Daniel D.

2017-01-01

Restrictive angling regulations in tailwater trout fisheries may be unsuccessful if food availability limits energy for fish to grow. We examined spatial and temporal variation in energy intake and growth in populations of Brown Trout Salmo trutta and Rainbow Trout Oncorhynchus mykiss within three catch-and-release (C-R) areas in Arkansas tailwaters to evaluate food availability compared with consumption. Based on bioenergetic simulations, Rainbow Trout fed at submaintenance levels in both size-classes (≤400 mm TL, >400 mm TL) throughout most seasons. A particular bottleneck in food availability occurred in the winter for Rainbow Trout when the daily ration was substantially below the minimum required for maintenance, despite reduced metabolic costs associated with lower water temperatures. Rainbow Trout growth rates followed a similar pattern to consumption with negative growth rates during the winter periods. All three size-classes (400 mm TL) of Brown Trout experienced high growth rates and limited temporal bottlenecks in food availability. We observed higher mean densities for Rainbow Trout (47–342 fish/ha) than for Brown Trout (3–84 fish/ha) in all C-R areas. Lower densities of Brown Trout coupled with an ontogenetic shift towards piscivory may have allowed for higher growth rates and sufficient consumption rates to meet energetic demands. Brown Trout at current densities were more effective in maintaining adequate growth rates and larger sizes in C-R areas than were Rainbow Trout. Bioenergetic simulations suggest that reducing stocking levels of Rainbow Trout in the tailwaters may be necessary in order to achieve increased catch rates of larger trout in the C-R areas.

Effects of some chelating agents on the uptake and distribution of 203Hg2+ in the brown trout (Salmo trutta): Studies on ethyl- and isopropylxanthate diethyl- and diisopropyldithiophosphate, dimethyl- and diethyldithiocarbamate and pyridinethione

International Nuclear Information System (INIS)

Borg, K.; Gottofrey, J.; Tjaelve, H.

1988-01-01

Brown trout, Salmo trutta, were exposed to water containing 0.1 μg/l 203 Hg 2+ , alone or with potassium ethylxanthate (PEX), sodium isopropylxanthate (SIX), sodium diethyldithiophosphate (SEP), sodium diisopropyldithiophosphate (SIP), sodium dimethyldithiocarbamate (SMC), sodium diethyldithiocarbamate (SEC) or sodium pyridinethione (SPyr), respectively. After 1 week the uptake and distribution of the 203 Hg 2+ in the fish were examined by gamma spectrometry, SIX, SIP, SMC, SEC and SPyr induced 2-3 times higher 203 Hg 2+ concentrations in most tissues in comparison with trout exposed to 203 Hg 2+ only. In the trout exposed to PEX slightly enhanced 203 Hg 2+ levels were found only in some tissues, and after exposure to SEP a few tissues showed decreased 203 Hg 2+ concentrations. Determinations of chloroform/water partition coefficients showed that lipophilic chelates are formed between all the examined substances and the 203 Hg 2+ . However, SIX, SIP, SMC, SEC and SPyr, which induced markedly increased tissue levels of the metal, formed 203 Hg 2+ complexes with higher lipophilicities than SEX and SEP. A facilitated penetration of the lipophilic 203 Hg 2+ complexes over the gill membranes may underly the increment in the tissue levels of the metal, and the relative lipophilicity of the complexes may be of importance for this effect. In some instances, as with SEP, the 203 Hg 2+ chelated in complexes with low lipophilicity may even be less able to acumulate in some tissues than the non-complexed metal. (orig.)

River transport of mercury from artisanal and small-scale gold mining and risks for dietary mercury exposure in Madre de Dios, Peru.

Science.gov (United States)

Diringer, Sarah E; Feingold, Beth J; Ortiz, Ernesto J; Gallis, John A; Araújo-Flores, Julio M; Berky, Axel; Pan, William K Y; Hsu-Kim, Heileen

2015-02-01

Artisanal and small-scale gold mining (ASGM) is a major contributor to deforestation and the largest anthropogenic source of atmospheric mercury worldwide. Despite significant information on the direct health impacts of mercury to ASGM miners, the impact of mercury contamination on downstream communities has not been well characterized, particularly in Peru's Madre de Dios region. In this area, ASGM has increased significantly since 2000 and has led to substantial political and social controversy. This research examined the spatial distribution and transport of mercury through the Madre de Dios River with distance from ASGM activity. This study also characterized risks for dietary mercury exposure to local residents who depend on fish from the river. River sediment, suspended solids from the water column, and fish samples were collected in 2013 at 62 sites near 17 communities over a 560 km stretch of the Madre de Dios River and its major tributaries. In areas downstream of known ASGM activity, mercury concentrations in sediment, suspended solids, and fish within the Madre de Dios River were elevated relative to locations upstream of mining. Fish tissue mercury concentrations were observed at levels representing a public health threat, with greater than one-third of carnivorous fish exceeding the international health standard of 0.5 mg kg(-1). This study demonstrates that communities located hundreds of kilometers downstream of ASGM activity, including children and indigenous populations who may not be involved in mining, are at risk of dietary mercury exposure that exceed acceptable body burdens. This report represents the first systematic study of the region to aid policy decision-making related to ASGM activities in Peru.

Tissue-specific bioaccumulation and oxidative stress responses in juvenile Japanese flounder ( Paralichthys olivaceus) exposed to mercury

Science.gov (United States)

Huang, Wei; Cao, Liang; Ye, Zhenjiang; Lin, Longshan; Chen, Quanzhen; Dou, Shuozeng

2012-07-01

To understand mercury (Hg) toxicity in marine fish, we measured Hg accumulation in juvenile Japanese flounder ( Paralichthys olivaceus) and assessed the effects on growth and antioxidant responses. After Hg exposure (control, 5, 40, and 160 μg/L Hg) for 28 d, fish growth was significantly reduced. The accumulation of Hg in fish was dose-dependent and tissue-specific, with the maximum accumulation in kidney and liver, followed by gills, bone, and muscle. Different antioxidants responded differently to Hg exposure to cope with the induction of lipid peroxidation (LPO), which was also tissue-specific and dosedependent. As Hg concentration increased, superoxide dismutase (SOD) and catalase (CAT) activities increased significantly, whereas glutathione S -transferase (GST) activity and glutathione (GSH) levels decreased significantly in the gills. SOD and glutathione peroxidase (GPx) activities and the GSH level increased significantly in the liver. SOD activity and GSH levels increased significantly, but CAT activity decreased significantly with an increase in Hg concentration in the kidney. LPO was induced significantly by elevated Hg in the gills and kidney but was least affected in the liver. Therefore, oxidative stress biomarkers in gills were more sensitive than those in the liver and kidney to Hg exposure. Thus, the gills have potential as bioindicators for evaluating Hg toxicity in juvenile flounder.

Association between Blood Mercury Level and Visceral Adiposity in Adults

Directory of Open Access Journals (Sweden)

Jong Suk Park

2017-01-01

Full Text Available BackgroundFew studies have examined the association between mercury exposure and obesity. The aim of this study is to investigate the association between blood mercury concentrations and indices of obesity in adults.MethodsA total of 200 healthy subjects, aged 30 to 64 years, who had no history of cardiovascular or malignant disease, were examined. Anthropometric and various biochemical profiles were measured. Visceral adipose tissue (VAT was measured using dual-energy X-ray absorptiometry (DXA.ResultsAll subjects were divided into three groups according to blood mercury concentrations. Compared with the subjects in the lowest tertile of mercury, those in the highest tertile were more likely to be male; were current alcohol drinkers and smokers; had a higher body mass index (BMI, waist circumference (WC, and VAT; had higher levels of blood pressure, fasting glucose, and insulin resistance; and consumed more fish. The blood mercury concentration was significantly associated with anthropometric parameters, showing relationships with BMI, WC, and VAT. After adjusting for multiple risk factors, the odds ratios (ORs for high mercury concentration was significantly higher in the highest VAT tertile than in the lowest VAT tertile (OR, 2.66; 95% confidence interval, 1.05 to 6.62; P<0.05.ConclusionThe blood mercury concentration was significantly associated with VAT in healthy adults. Further studies are warranted to confirm our findings.

Impacts of Northern Pike on stocked Rainbow Trout in Pactola Reservoir, South Dakota

Science.gov (United States)

Scheibel, Natalie C.; Dembkowski, Daniel J.; Davis, Jacob L.; Chipps, Steven R.

2016-01-01

Establishment of nonnative Northern Pike Esox lucius in Pactola Reservoir, South Dakota, has prompted concern among biologists about the influence of this species on the lake’s intensively managed salmonid fisheries. Ancedotal information suggests that catch rates of Rainbow Trout Oncorhynchus mykiss have declined while mean size and abundance of Northern Pike has increased, although quantitative information on diet and growth of the Northern Pike population is lacking. To address potential interactions between Northern Pike and Rainbow Trout, we assessed size-dependent predation by Northern Pike on Rainbow Trout and determined the relative energetic contribution of stocked Rainbow Trout to Northern Pike growth using bioenergetics modeling. Stable isotopes combined with traditional diet analyses revealed that smaller Northern Pike (Trout contributed less than 10% to their annual energy consumption. In contrast, larger Northern Pike (≥600 mm TL) consumed primarily Rainbow Trout, which accounted for 56% of their annual energy consumption. Combining estimates of Northern Pike predation with production costs of catchable-size Rainbow Trout revealed that annual economic losses ranged from US$15,259 to $24,801 per year. Over its lifespan, an age-10 Northern Pike was estimated to consume ~117 Rainbow Trout worth approximately $340. Thus, Northern Pike predation substantially influences salmonid management initiatives and is likely a primary factor contributing to reduced Rainbow Trout abundance and return to anglers in Pactola Reservoir. Strategies for reducing Northern Pike predation on Rainbow Trout include increasing the size of stocked fish or altering the timing and spatial distribution of stocking events.

Kootenai River fisheries investigations: rainbow and bull trout recruitment: annual progress report 1999; ANNUAL

International Nuclear Information System (INIS)

Walters, Jody P.; Downs, Christopher Charles

2001-01-01

Our 1999 objectives were to determine sources of rainbow trout Oncorhynchus mykiss and bull trout Salvelinus confluentus spawning and recruitment in the Idaho reach of the Kootenai River. We used a rotary-screw trap to capture juvenile trout to determine age at out-migration and to estimate total out-migration from the Boundary Creek drainage to the Kootenai River. The out-migrant estimate for March through August 1999 was 1,574 (95% C. I.= 825-3,283) juvenile rainbow trout. Most juveniles out-migrated at age-2 and age-3. No out-migrating bull trout were caught. Five of 17 rainbow trout radio-tagged in Idaho migrated upstream into Montana waters during the spawning season. Five bull trout originally radio-tagged in O'Brien Creek, Montana in early October moved downstream into Idaho and British Columbia by mid-October. Annual angler exploitation for the rainbow trout population upstream of Bonners Ferry, Idaho was estimated to be 58%. Multi-pass depletion estimates for index reaches of Caboose, Curley, and Debt creeks showed 0.20, 0.01, and 0.13 rainbow trout juveniles/m(sup 2), respectively. We estimated rainbow trout (180-415 mm TL) standing stock of 1.6 kg/ha for the Hemlock Bar reach (29.4 ha) of the Kootenai River, similar to the 1998 estimate. Recruitment of juvenile rainbow and bull trout from Idaho tributaries is not sufficient to be the sole source of subsequent older fish in the mainstem Kootenai River. These populations are at least partly dependent on recruitment from Montana waters. The low recruitment and high exploitation rate may be indicators of a rainbow trout population in danger of further decline

Environmental monitoring of the La Grande complex (2003-2004) : evolution of mercury levels in the flesh of fish; Reseau de suivi environnemental du complexe La Grande (2003-2004) : evolution du mercure dans la chair des poissons

Energy Technology Data Exchange (ETDEWEB)

Therrien, J. [Genivar SEC, Quebec, PQ (Canada); Schetagne, R. [Hydro-Quebec Production, Baie-Comeau, PQ (Canada)

2005-11-15

The results of surveys conducted to assess the duration of temporary mercury levels in piscivorous species in the La Grande Complex were presented. A 2003 survey conducted in the easter sector and a 2004 survey conducted in the western sector of the complex showed that for non-piscivorous fishes of standardized length, a return to mean natural mercury levels will be achieved between 10 and 20 years after impounding. For piscivorous fishes, the evolution pattern of the mean mercury levels suggested that a return to background levels will occur after 20 to 30 years. Mercury levels for northern pike in the Robert-Bourassa Reservoir are expected to return to normal levels after 30 to 35 years. The surveys indicated that mean mercury levels in non-piscivorous fishes were often higher immediately below the La Grande generating stations. Similar observations were made for northern pike and lake trout downstream of the generating stations in the eastern sector of the complex. Mean mercury levels were significantly higher for fishes in the complex than fishes in the natural lakes of the region. Results of the surveys suggested that additional consumption restrictions for piscivorous fishes in the reservoirs are needed. Consumption guidelines for varieties of non-piscivorous and piscivorous fishes from the complex were included.

Wigwam River Juvenile Bull Trout and Fish Habitat Monitoring Program : 2002 Data Report.

Energy Technology Data Exchange (ETDEWEB)

Cope, R.S. [Westslope Fisheries, Cranbrook, BC, Canada

2003-03-01

The Wigwam River bull trout (Salvelinus confluentus) and fish habitat monitoring program is a trans-boundary initiative implemented by the British Columbia Ministry of Water, Land, and Air Protection (MWLAP), in cooperation with Bonneville Power Administration (BPA). The Wigwam River is an important fisheries stream located in southeastern British Columbia that supports healthy populations of both bull trout and Westslope cutthroat trout (Figure 1). This river has been characterized as the single most important bull trout spawning stream in the Kootenay Region (Baxter and Westover 2000, Cope 1998). In addition, the Wigwam River supports some of the largest Westslope cutthroat trout (Oncorhynchus clarki lewisi) in the Kootenay Region. These fish are highly sought after by anglers (Westover 1999a, 1999b). Bull trout populations have declined in many areas of their range within Montana and throughout the northwest including British Columbia. Bull trout were blue listed as vulnerable in British Columbia by the B.C. Conservation Data Center (Cannings 1993) and although there are many healthy populations of bull trout in the East Kootenay they remain a species of special concern. Bull trout in the United States portion of the Columbia River were listed as threatened in 1998 under the Endangered Species Act by the U.S. Fish and Wildlife Service. The upper Kootenay River is within the Kootenai sub-basin of the Mountain Columbia Province, one of the eleven Eco-provinces that make up the Columbia River Basin. MWLAP applied for and received funding from BPA to assess and monitor the status of wild, native stocks of bull trout in tributaries to Lake Koocanusa (Libby Reservoir) and the upper Kootenay River. This task is one of many that were undertaken to ''Monitor and Protect Bull Trout for Koocanusa Reservoir'' (BPA Project Number 2000-04-00).

The global impact of alien trout species — a review; with reference ...

African Journals Online (AJOL)

Brown trout, Salmo trutta, and rainbow trout, Oncorhynchus mykiss, were first introduced into South African waters as angling species in the later part of the nineteenth century, when environmental impact studies were neither considered nor undertaken. Trout have since been introduced mainly into the cooler upper ...

ERM booster vaccination of Rainbow trout using diluted bacterin

DEFF Research Database (Denmark)

Schmidt, Jacob Günther; Henriksen, Niels H.; Buchmann, Kurt

2016-01-01

under laboratory conditions extend the protection period. The present field study investigated the applicability of the method under practical farming conditions (freshwater earth ponds supplied by stream water). Primary immersion vaccination of trout (3–4 g) for 30 s in Y. ruckeri bacterin (diluted 1......Enteric Red Mouth Disease ERM caused by Yersinia ruckeri infection is associated with morbidity and mortality in salmonid farming but immersion vaccination of fry may confer some protection for a number of months. Revaccination of rainbow trout, even by use of diluted ERM immersion vaccine, can......:10) in April 2015 was followed 3 months later (July 2015) by 1 h bathing of rainbow trout in bacterin (diluted 1:650 or 1:1700) in order to evaluate if this time saving vaccination methodology can improve immunity and protection. Trout were subjected in farms to natural Y. ruckeri exposure in June and July...

Maternally transferred mercury in wild largemouth bass, Micropterus salmoides.

Science.gov (United States)

Sackett, Dana K; Aday, D Derek; Rice, James A; Cope, W Gregory

2013-07-01

Maternal transfer of mercury in fish represents a potential route of elimination for adult females and a risk to developing embryos. To better quantify maternal transfer, we measured Hg in female largemouth bass (Micropterus salmoides) muscle and eggs from six waterbodies. Mercury in eggs from two waterbodies exceeded a US federal screening level (0.3 μg g(-1)) and was likely high enough to cause adverse reproductive effects. We found a curvilinear relationship between female and egg Hg. Fish with 0.37 μg g(-1) showed a direct relationship between egg and muscle Hg (Log10 egg Hg = -1.03 + 1.18 * log10 muscle tissue Hg + 2.15 * (log10 muscle tissue Hg + 0.35)(2)). We also report higher maternal transfer (0.2-13.2%) and higher ratios of egg to muscle tissue Hg (4-52%) and egg to whole body Hg concentrations (7-116%) than previously observed for teleost fish. Published by Elsevier Ltd.

Ionoregulatory disruption as the acute toxic mechanism for lead in the rainbow trout (Oncorhynchus mykiss)

International Nuclear Information System (INIS)

Rogers, J.T.; Richards, J.G.; Wood, C.M.

2003-01-01

The mechanism for acute toxicity of lead (Pb) in rainbow trout (Oncorhynchus mykiss) was investigated at Pb concentrations close to the 96 h LC50 of 1.0 mg dissolved Pb l -1 (0.8-1.4, 95% C.I.) determined in dechlorinated Hamilton city tap water (from Lake Ontario, hardness=140 mg l -1 CaCO 3 ). Tissue Pb accumulation associated with death was highest in the gill, followed by kidney and liver. Significant ionoregulatory impacts were observed in adult rainbow trout (200-300 g) fitted with indwelling dorsal aortic catheters and exposed to 1.1±0.04 mg dissolved Pb l -1 . Decreased plasma [Ca 2+ ], [Na + ] and [Cl - ] occurred after 48 h of exposure through to 120 h, with increases in plasma [Mg 2+ ], ammonia, and cortisol. No marked changes in PaO 2 , PaCO 2 , pH, glucose, or hematological parameters were evident. Branchial Na + /K + ATPase activity in juvenile trout exposed to concentrations close to the 96 h LC50 was inhibited by approximately 40% after 48 h of Pb exposure. Calcium ion flux measurements using 45 Ca as a radiotracer showed 65% inhibition of Ca 2+ influx after 0, 12, 24 or 48 h exposure to the 96 h LC50 concentration of Pb. There was also significant inhibition (40-50%) of both Na + and Cl - uptake, measured with 22 Na and 36 Cl simultaneously. We conclude that the mechanism of acute toxicity for Pb in rainbow trout occurs by ionoregulatory disruption rather than respiratory or acid/base distress at Pb concentrations close to the 96 h LC50 in moderately hard water

Mercury and Your Health

Science.gov (United States)

... the Risk of Exposure to Mercury Learn About Mercury What is Mercury What is Metallic mercury? Toxicological Profile ToxFAQs Mercury Resources CDC’s National Biomonitoring Program Factsheet on Mercury ...

Gastrointestinal uptake and fate of cadmium in rainbow trout acclimated to sublethal dietary cadmium

International Nuclear Information System (INIS)

Chowdhury, M.J.; McDonald, D.G.; Wood, C.M.

2004-01-01

Adult rainbow trout were pre-exposed to a sublethal concentration of dietary Cd (500 mg/kg dry wt.) for 30 days to induce acclimation. A gastrointestinal dose of radiolabeled Cd (276 μg/kg wet wt.) was infused into the stomach of non-acclimated and Cd-acclimated trout through a stomach catheter. Repetitive blood samples over 24 h and terminal tissue samples were taken to investigate the gastrointestinal uptake, plasma clearance kinetics, and tissue distribution of Cd. Only a small fraction of the infused dose (non-acclimated: 2.4%; Cd-acclimated: 6.6%) was internalized across the gut wall, while most was bound in the gut tissues (10-24%) or remained in the lumen (16-33%) or lost from the fish (∼50%) over 24 h. Cadmium loading during pre-exposure produced a profound increase of total Cd in the blood plasma (∼28-fold) and red blood cells (RBC; ∼20-fold). The plasma Cd-time profiles consisted of an apparent rising (uptake) phase and a declining (clearance) phase with a maximum value of uptake in 4 h, suggesting that uptake of gastrointestinally infused Cd was very rapid. Acclimation to dietary Cd did not affect plasma Cd clearance (∼0.5 ml/min), but enhanced new Cd levels in the plasma (but not in the RBC), and resulted in a longer half-life for plasma Cd. Tissue total and new Cd levels varied in different regions of the gastrointestinal tract, and overall levels in gut tissues were much greater than in non-gut tissues, reflecting the Cd exposure route. Dietary Cd, but not the infused Cd, greatly increased total Cd levels of all gut tissues in the order posterior-intestine (640-fold) > cecae (180-fold) > mid-intestine (94-fold) > stomach (53-fold) in Cd-acclimated fish relative to naieve fish. Among non-gut tissues in the Cd-acclimated fish, the great increases of total Cd levels were observed in the liver (73-fold), kidney (39-fold), carcass (35-fold), and gills (30-fold). The results provide some clear conclusions that may be useful for environmental risk

Mercury and omega-3 fatty acid profiles in freshwater fish of the Dehcho Region, Northwest Territories: Informing risk benefit assessments.

Science.gov (United States)

Laird, Matthew J; Henao, Juan J Aristizabal; Reyes, Ellen S; Stark, Ken D; Low, George; Swanson, Heidi K; Laird, Brian D

2018-05-17

Traditional foods have significant nutritional, sociocultural and economic value in subarctic First Nations communities of the Northwest Territories, and play a crucial role in promoting cultural continuity and sovereignty. Omega-3 polyunsaturated fatty acids (N-3 PUFAs), including eicosapentaenoic (EPA) and docosahexaenoic acid (DHA), carry significant benefits for neurocognitive development and cardiovascular health. However, the health risks posed by methylmercury may serve to undermine the benefits of fish consumption in Northern Indigenous communities. The objective of this study was to characterize profiles for mercury (Hg) and fatty acids in fish species harvested across lakes of the Dehcho Region, in the Mackenzie Valley of the Northwest Territories, to better understand the risks and benefits associated with traditional foods. Hg levels increased with trophic position, with the highest levels found in Burbot, Lake Trout, Walleye, and Northern Pike. Lake Trout, along with planktivorous species including Lake Whitefish, Cisco, and Sucker, demonstrated higher N-3 PUFAs than other species. Negative associations were observed between Hg and N-3 PUFAs in Lake Trout, Northern Pike, Walleye and Burbot. Further stratifying these relationships revealed significant interactions by lake. Significant differences observed in fatty acid and Hg profiles across lakes underscore the importance of considering both species- and lake-specific findings. This growing dataset of freshwater fish of the Dehcho will inform future efforts to characterize human Hg exposure profiles using probabilistic dose reconstruction models. Copyright © 2018 Elsevier B.V. All rights reserved.

1,2-Dibromoethane and chloroform in the rainbow trout (salmo gairdneri): Studies on the distribution of nonvolatile and irreversibly bound metabolites

International Nuclear Information System (INIS)

Darnerud, P.O.; Lund, B.O.; Brittebo, E.B.; Brandt, I.

1989-01-01

The disposition of metabolites from 14 C-labeled 1,2-dibromoethane (DBE) and chloroform (CF) in juvenile rainbow trout was studied by autoradiography and quantitation of tissue radioactivity. Whole-body autoradiography of heated tissue sections showed a considerable level of nonvolatile metabolites of DBE and CF in the liver and certain areas of the body kidney. A lower level of metabolites appeared in the gills, intestinal mucosa, and olfactory rosettes in trouts exposed to DBE- or CF-containing water. Unlike previous studies in rodents, no specific uptake or binding of DBE or CF occurred in the surface epithelia of the upper alimentary tract. Microautoradiography and exhaustive tissue extraction confirmed a high irreversible binding of DBE metabolites in the liver and in a proximal tubular segment of the body kidney in fish exposed to DBE-containing water. A high level of radioactivity in the bile indicated fecal excretion of metabolites from both compounds. The results suggest that there is marked metabolism of DBE and CF in the liver and kidney, whereas the metabolism in the surface epithelia is low. The liver and kidney are proposed to be target organs of toxicity in fish

Feeding mice with diets containing mercury-contaminated fish flesh from French Guiana: a model for the mercurial intoxication of the Wayana Amerindians

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Rossignol Rodrigue

2008-10-01

Full Text Available Abstract Background In 2005, 84% of Wayana Amerindians living in the upper marshes of the Maroni River in French Guiana presented a hair mercury concentration exceeding the limit set up by the World Health Organization (10 μg/g. To determine whether this mercurial contamination was harmful, mice have been fed diets prepared by incorporation of mercury-polluted fish from French Guiana. Methods Four diets containing 0, 0.1, 1, and 7.5% fish flesh, representing 0, 5, 62, and 520 ng methylmercury per g, respectively, were given to four groups of mice for a month. The lowest fish regimen led to a mercurial contamination pressure of 1 ng mercury per day per g of body weight, which is precisely that affecting the Wayana Amerindians. Results The expression of several genes was modified with mercury intoxication in liver, kidneys, and hippocampus, even at the lowest tested fish regimen. A net genetic response could be observed for mercury concentrations accumulated within tissues as weak as 0.15 ppm in the liver, 1.4 ppm in the kidneys, and 0.4 ppm in the hippocampus. This last value is in the range of the mercury concentrations found in the brains of chronically exposed patients in the Minamata region or in brains from heavy fish consumers. Mitochondrial respiratory rates showed a 35–40% decrease in respiration for the three contaminated mice groups. In the muscles of mice fed the lightest fish-containing diet, cytochrome c oxidase activity was decreased to 45% of that of the control muscles. When mice behavior was assessed in a cross maze, those fed the lowest and mid-level fish-containing diets developed higher anxiety state behaviors compared to mice fed with control diet. Conclusion We conclude that a vegetarian diet containing as little as 0.1% of mercury-contaminated fish is able to trigger in mice, after only one month of exposure, disorders presenting all the hallmarks of mercurial contamination.

Vertebral column deformities in farmed rainbow trout ( Oncorhynchus mykiss )

DEFF Research Database (Denmark)

Madsen, Lone; Dalsgaard, Inger

1999-01-01

Farmed rainbow trout (Oncorhynchus mykiss) were fed diets with either different levels of vitamin C, or diets enriched with glucan or chitin, from feeding start and 6 months onwards. At an average weight of 100 g, the trout were X-rayed to determine the deformity level. The investigations showed...... of deformities (4.8%). In all groups examined, the deformities were spread over the whole vertebral column. The deformities in the group fed the low vitamin C diet were more severe than those found in the other groups. An outbreak of the disease rainbow trout fry syndrome (RTFS) caused by the bacterium...

Evaluation of an Unsuccessful Brook Trout Electrofishing Removal Project in a Small Rocky Mountain Stream.

Energy Technology Data Exchange (ETDEWEB)

Meyer, Kevin A.; Lamansky, Jr., James A.; Schill, Daniel J.

2006-01-26

In the western United States, exotic brook trout Salvelinus fontinalis frequently have a deleterious effect on native salmonids, and biologists often attempt to remove brook trout from streams by means of electrofishing. Although the success of such projects typically is low, few studies have assessed the underlying mechanisms of failure, especially in terms of compensatory responses. A multiagency watershed advisory group (WAG) conducted a 3-year removal project to reduce brook trout and enhance native salmonids in 7.8 km of a southwestern Idaho stream. We evaluated the costs and success of their project in suppressing brook trout and looked for brook trout compensatory responses, such as decreased natural mortality, increased growth, increased fecundity at length, and earlier maturation. The total number of brook trout removed was 1,401 in 1998, 1,241 in 1999, and 890 in 2000; removal constituted an estimated 88% of the total number of brook trout in the stream in 1999 and 79% in 2000. Although abundance of age-1 and older brook trout declined slightly during and after the removals, abundance of age-0 brook trout increased 789% in the entire stream 2 years after the removals ceased. Total annual survival rate for age-2 and older brook trout did not decrease during the removals, and the removals failed to produce an increase in the abundance of native redband trout Oncorhynchus mykiss gairdneri. Lack of a meaningful decline and unchanged total mortality for older brook trout during the removals suggest that a compensatory response occurred in the brook trout population via reduced natural mortality, which offset the removal of large numbers of brook trout. Although we applaud WAG personnel for their goal of enhancing native salmonids by suppressing brook trout via electrofishing removal, we conclude that their efforts were unsuccessful and suggest that similar future projects elsewhere over such large stream lengths would be costly, quixotic enterprises.

Brook trout movement within a high-elevation watershed: Consequences for watershed restoration

Science.gov (United States)

Jeff L. Hansbarger; J. Todd Petty; Patricia M. Mazik

2010-01-01

We used radio-telemetry to quantify brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta) movements in the Shavers Fork of the Cheat River, West Virginia, and an adjacent second-order tributary (Rocky Run). Our objectives were to quantify the overall rate of trout movement, assess spatial and temporal variation in...

Intravenous injection of unfunctionalized carbon-based nanomaterials confirms the minimal toxicity observed in aqueous and dietary exposures in juvenile rainbow trout (Oncorhynchus mykiss).

Science.gov (United States)

Boyle, David; Sutton, Paul A; Handy, Richard D; Henry, Theodore B

2018-01-01

Numerous ecotoxicology studies of carbon-based nanomaterials (CNMs) have been conducted in fishes; however, different approaches have been used to make CNM dispersions and dose tanks for aqueous exposures, and to prepare food containing CNMs for dietary studies. This diversity of experimental methods has led to conflicting results and difficulties in comparing studies. The objective of the present study was to evaluate intravenous injection of unfunctionalized CNMs in rainbow trout (Oncorhynchus mykiss), as a means of delivering a known internal dose, on tissue biochemistry and histopathological lesions; then, subsequently, to compare the results with our previous work on aqueous and dietary exposures of rainbow trout to CNMs. Rainbow trout were injected in the caudal vein with corn oil dispersions of 200 μg (approximately 1 μg g -1 ) of either the fullerene C 60 , single-walled carbon nanotubes (SWCNTs), or amorphous carbon black. After 96 h, injected fish were euthanized and tissue samples collected for biochemistry and histology. Histological examination of the kidney of fish injected intravenously indicated the presence of black material consistent with the injected carbon treatments. However, there were no additional lesions associated with CNM exposure compared to controls. There were also no significant changes in haematology, or ionoregulatory disturbance in blood plasma among the intravenously injected fish. Significant elevation in lipid peroxidation (thiobarbituric acid reactive substances TBARS) was detected only in kidney and spleen of fish injected with SWCNTs, but not the other carbon treatments. The elevated TBARS following injection contrasted with CNMs delivered via aqueous or dietary routes in our previous studies, suggesting that the latter exposure routes may not lead to absorption and toxicity in the internal tissues. Comparison of the effects of injected CNMs with aqueous and dietary CNMs exposures indicates that these materials are of

Potential population and assemblage influences of non-native trout on native nongame fish in Nebraska headwater streams

Science.gov (United States)

Turek, Kelly C.; Pegg, Mark A.; Pope, Kevin L.; Schainost, Steve

2014-01-01

Non-native trout are currently stocked to support recreational fisheries in headwater streams throughout Nebraska. The influence of non-native trout introductions on native fish populations and their role in structuring fish assemblages in these systems is unknown. The objectives of this study were to determine (i) if the size structure or relative abundance of native fish differs in the presence and absence of non-native trout, (ii) if native fish-assemblage structure differs in the presence and absence of non-native trout and (iii) if native fish-assemblage structure differs across a gradient in abundances of non-native trout. Longnose dace Rhinichthys cataractae were larger in the presence of brown trout Salmo trutta and smaller in the presence of rainbow trout Oncorhynchus mykiss compared to sites without trout. There was also a greater proportion of larger white suckers Catostomus commersonii in the presence of brown trout. Creek chub Semotilus atromaculatus and fathead minnow Pimephales promelas size structures were similar in the presence and absence of trout. Relative abundances of longnose dace, white sucker, creek chub and fathead minnow were similar in the presence and absence of trout, but there was greater distinction in native fish-assemblage structure between sites with trout compared to sites without trout as trout abundances increased. These results suggest increased risk to native fish assemblages in sites with high abundances of trout. However, more research is needed to determine the role of non-native trout in structuring native fish assemblages in streams, and the mechanisms through which introduced trout may influence native fish populations.

Hematological Changes Induced by Mercury Ions and Ionizing Radiation in Experimental Animals

International Nuclear Information System (INIS)

Kim, Jin-Kyu; Lee, Yun-Jong; Choi, Dae-Seong; Kim, Ji-Hyang; Cebulska-Wasilewska, Antonina

2006-01-01

Toxic metals such as lead, chromium, cadmium, mercury and arsenic are widely found in our environment. Humans are exposed to these metals from numerous sources, including contaminated air, water, soil and food. Mercury, one of the most diffused and hazardous organ specific environmental contaminants, exists in a wide variety of physical and chemical states, each of which has unique characteristics for a target organ specificity. Although reports indicate that mercury induces deleterious damage, little is known about its effects on living organisms. Ionizing radiation, an extensively used therapeutic modality in oncology, not only eradicates neoplastic cells but also generates inevitable side effects for normal tissues. Such biological effects are made through the production of reactive oxygen species which include a superoxide anion, a hydroxyl radical and a hydrogen peroxide. These reactive species may contribute to the radiation-induced cytotoxicity (e.g., chromosome aberrations, protein oxidation, and muscle injury) and to the metabolic and morphologic changes (e.g., increased muscle proteolysis and changes in the central nervous system) in animals and humans. In the present study, radioimmunoassay of the cortisol in the serum and the analysis of the hematological components and enzymes related to a tissue injury were carried out to evaluate the effects of mercury chloride in comparison with those of ionizing radiation

Hematological Changes Induced by Mercury Ions and Ionizing Radiation in Experimental Animals

Energy Technology Data Exchange (ETDEWEB)

Kim, Jin-Kyu; Lee, Yun-Jong; Choi, Dae-Seong [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Kim, Ji-Hyang [Biotechnology Research Institute, Seoul (Korea, Republic of); Cebulska-Wasilewska, Antonina [The Henryk Niewodniczanski Institute of Nuclear Physics, Krakow (Poland)

2006-07-01

Toxic metals such as lead, chromium, cadmium, mercury and arsenic are widely found in our environment. Humans are exposed to these metals from numerous sources, including contaminated air, water, soil and food. Mercury, one of the most diffused and hazardous organ specific environmental contaminants, exists in a wide variety of physical and chemical states, each of which has unique characteristics for a target organ specificity. Although reports indicate that mercury induces deleterious damage, little is known about its effects on living organisms. Ionizing radiation, an extensively used therapeutic modality in oncology, not only eradicates neoplastic cells but also generates inevitable side effects for normal tissues. Such biological effects are made through the production of reactive oxygen species which include a superoxide anion, a hydroxyl radical and a hydrogen peroxide. These reactive species may contribute to the radiation-induced cytotoxicity (e.g., chromosome aberrations, protein oxidation, and muscle injury) and to the metabolic and morphologic changes (e.g., increased muscle proteolysis and changes in the central nervous system) in animals and humans. In the present study, radioimmunoassay of the cortisol in the serum and the analysis of the hematological components and enzymes related to a tissue injury were carried out to evaluate the effects of mercury chloride in comparison with those of ionizing radiation.

Sedentary nestlings of Wood Stork as monitors of mercury contamination in the gold mining region of the Brazilian Pantanal

Energy Technology Data Exchange (ETDEWEB)

Nassif Del Lama, Silvia, E-mail: dsdl@ufscar.br [Laboratorio Genetica de Aves, Departamento de Genetica e Evolucao, Universidade Federal de Sao Carlos, Rodovia Washington Luis km 235, 13565-905 Sao Carlos, Sao Paulo (Brazil); Dosualdo Rocha, Cristiano [Laboratorio Genetica de Aves, Departamento de Genetica e Evolucao, Universidade Federal de Sao Carlos, Rodovia Washington Luis km 235, 13565-905 Sao Carlos, Sao Paulo (Brazil); Figueiredo Jardim, Wilson [Institute of Chemistry, State University of Campinas, P.O. Box 6154, 13083-970 Sao Paulo (Brazil); Tsai, Jo-Szu; Frederick, Peter Crawford [Department of Wildlife Ecology and Conservation, P.O. Box 110430, University of Florida, Gainesville, FL 32611 (United States)

2011-11-15

Sedentary organisms that are at top trophic levels allow inference about the level of local mercury contamination. We evaluated mercury contamination in feather tissue of nestling Wood Storks (Mycteria americana), sampled in different parts of the Brazilian Pantanal that were variably polluted by mercury releases from gold mining activities. Levels of mercury in feathers sampled in seven breeding colonies were determined by atomic absorption spectroscopy, and the mean value of mercury concentration was 0.557 {mu}g/g, dry weight (n=124), range 0.024-4.423 {mu}g/g. From this total sample, 21 feathers that represent 30% of nestlings collected in Porto da Fazenda and Tucum colonies, in the northern region, ranged from 1.0 to 4.43 {mu}g/g, dry weight (median value=1.87 {mu}g/g). We found significant differences among regions (H=57.342; p=0<0.05). Results suggest that permanently flooded areas, or along mainstream rivers are more contaminated by mercury than dry areas, regardless of the distance from the gold mining center, which is located in the northern Pantanal. Highest values found in nestlings feathers were similar to those found in feathers of adult birds and in tissues of adult mammals that are less sedentary and were captured in the same region of Pantanal. These findings indicate that mercury released has been biomagnified and it is present in high concentrations in tissues of top consumers. We suggest a program to monitor mercury availability in this ecosystem using sedentary life forms of top predators like Wood Storks or other piscivorous birds. - Highlights: Black-Right-Pointing-Pointer Sedentary stork nestlings were used for the first time to show local mercury contamination of Pantanal. Black-Right-Pointing-Pointer Differences were found among regions but they are not explained only by distance from the gold mining. Black-Right-Pointing-Pointer Permanently flooded areas and areas along mainstream rivers are more contaminated than dry areas. Black

Sedentary nestlings of Wood Stork as monitors of mercury contamination in the gold mining region of the Brazilian Pantanal

International Nuclear Information System (INIS)

Nassif Del Lama, Silvia; Dosualdo Rocha, Cristiano; Figueiredo Jardim, Wilson; Tsai, Jo-Szu; Frederick, Peter Crawford

2011-01-01

Sedentary organisms that are at top trophic levels allow inference about the level of local mercury contamination. We evaluated mercury contamination in feather tissue of nestling Wood Storks (Mycteria americana), sampled in different parts of the Brazilian Pantanal that were variably polluted by mercury releases from gold mining activities. Levels of mercury in feathers sampled in seven breeding colonies were determined by atomic absorption spectroscopy, and the mean value of mercury concentration was 0.557 μg/g, dry weight (n=124), range 0.024–4.423 μg/g. From this total sample, 21 feathers that represent 30% of nestlings collected in Porto da Fazenda and Tucum colonies, in the northern region, ranged from 1.0 to 4.43 μg/g, dry weight (median value=1.87 μg/g). We found significant differences among regions (H=57.342; p=0<0.05). Results suggest that permanently flooded areas, or along mainstream rivers are more contaminated by mercury than dry areas, regardless of the distance from the gold mining center, which is located in the northern Pantanal. Highest values found in nestlings feathers were similar to those found in feathers of adult birds and in tissues of adult mammals that are less sedentary and were captured in the same region of Pantanal. These findings indicate that mercury released has been biomagnified and it is present in high concentrations in tissues of top consumers. We suggest a program to monitor mercury availability in this ecosystem using sedentary life forms of top predators like Wood Storks or other piscivorous birds. - Highlights: ► Sedentary stork nestlings were used for the first time to show local mercury contamination of Pantanal. ► Differences were found among regions but they are not explained only by distance from the gold mining. ► Permanently flooded areas and areas along mainstream rivers are more contaminated than dry areas. ► Mercury has been biomagnified in Pantanal and it is found in high concentrations in top

Safety on North Carolina and Kentucky trout farms.

Science.gov (United States)

Ogunsanya, T J; Durborow, R M; Myers, M L; Cole, H P; Thompson, S L

2011-01-01

The objective of this study was to identify and describe work-related safety hazards, injuries, and near-injury events (close calls) that occurred on trout farms in North Carolina and Kentucky. An interview instrument was used to collect information on occupational hazards, injuries, and near-injury events that resulted from work-related activities. Trout farmers reported occupational hazards including falling live tank lids, slippery surfaces on hauling trucks, lifting strains, falls from raceway walls and walkways, needlesticks while vaccinating fish, allergies, hypothermia/drowning, falls from cranes, chemical exposure, fire/explosions related to oxygen exposure, and electrical contact with overhead power lines. This study also reports solutions suggested by farm safety researchers or used by farmers to prevent the safety hazards found on trout farms.

The effect of farmed trout on cardiovascular risk markers in healthy men

DEFF Research Database (Denmark)

Hallund, Jesper; Madsen, Birgitte Overgaard; Bügel, Susanne H.

2010-01-01

, insulin, C-reactive protein (CRP) and other markers of inflammation were measured at weeks 0 and 8. RBC content of total n-3 LCPUFA, both EPA and DHA, was significantly higher among men consuming trout raised on marine feed compared with men consuming the vegetable-fed trout or chicken. The three...... meal with 150 g farmed trout raised on either marine or vegetable-based feed, or a reference meal containing 150 g chicken. Twenty-four hour BP, pulse wave velocity, augmentation index, fatty acid composition of erythrocyte (RBC), and concentrations of TAG, HDL-cholesterol, LDL-cholesterol, glucose...... risk markers after daily consumption of trout with high or low n-3 LCPUFA content. However, trout raised on vegetable-based feed had less pronounced impact on RBC n-3 LCPUFA status....

Brook trout passage performance through culverts

Science.gov (United States)

Goerig, Elsa; Castro-Santos, Theodore R.; Bergeron, Normand

2016-01-01

Culverts can restrict access to habitat for stream-dwelling fishes. We used passive integrated transponder telemetry to quantify passage performance of >1000 wild brook trout (Salvelinus fontinalis) attempting to pass 13 culverts in Quebec under a range of hydraulic and environmental conditions. Several variables influenced passage success, including complex interactions between physiology and behavior, hydraulics, and structural characteristics. The probability of successful passage was greater through corrugated metal culverts than through smooth ones, particularly among smaller fish. Trout were also more likely to pass at warmer temperatures, but this effect diminished above 15 °C. Passage was impeded at higher flows, through culverts with steep slopes, and those with deep downstream pools. This study provides insight on factors influencing brook trout capacity to pass culverts as well as a model to estimate passage success under various conditions, with an improved resolution and accuracy over existing approaches. It also presents methods that could be used to investigate passage success of other species, with implications for connectivity of the riverscape.

Impacts of Sublethal Mercury Exposure on Birds: A Detailed Review.

Science.gov (United States)

Whitney, Margaret C; Cristol, Daniel A

Mercury is a ubiquitous environmental contaminant known to accumulate in, and negatively affect, fish-eating and oceanic bird species, and recently demonstrated to impact some terrestrial songbirds to a comparable extent. It can bioaccumulate to concentrations of >1 μg/g in tissues of prey organisms such as fish and insects. At high enough concentrations, exposure to mercury is lethal to birds. However, environmental exposures are usually far below the lethal concentrations established by dosing studies.The objective of this review is to better understand the effects of sublethal exposure to mercury in birds. We restricted our survey of the literature to studies with at least some exposures >5 μg/g. The majority of sublethal effects were subtle and some studies of similar endpoints reached different conclusions. Strong support exists in the literature for the conclusion that mercury exposure reduces reproductive output, compromises immune function, and causes avoidance of high-energy behaviors. For some endpoints, notably certain measures of reproductive success, endocrine and neurological function, and body condition, there is weak or contradictory evidence of adverse effects and further study is required. There was no evidence that environmentally relevant mercury exposure affects longevity, but several of the sublethal effects identified likely do result in fitness reductions that could adversely impact populations. Overall, 72% of field studies and 91% of laboratory studies found evidence of deleterious effects of mercury on some endpoint, and thus we can conclude that mercury is harmful to birds, and the many effects on reproduction indicate that bird population declines may already be resulting from environmental mercury pollution.

Mercury Quick Facts: Health Effects of Mercury Exposure

Science.gov (United States)

... 2012 What are the Health Effects of Mercury Exposure? The health effects that can be caused by breathing mercury depend ... they breathe faster and have smaller lungs. Health effects caused by long-term exposure to mercury vapors • • Anxiety • • Excessive shyness • • Anorexia • • Sleeping ...

Using accelerated life testing procedures to compare the relative sensitivity of rainbow trout and the federally listed threatened bull trout to three commonly used rangeland herbicides (picloram, 2,4-D, and clopyralid).

Science.gov (United States)

Fairchild, James F; Allert, Ann; Sappington, Linda S; Nelson, Karen J; Valle, Janet

2008-03-01

We conducted 96-h static acute toxicity studies to evaluate the relative sensitivity of juveniles of the threatened bull trout (Salvelinus confluentus) and the standard cold-water surrogate rainbow trout (Onchorhyncus mykiss) to three rangeland herbicides commonly used for controlling invasive weeds in the northwestern United States. Relative species sensitivity was compared using three procedures: standard acute toxicity testing, fractional estimates of lethal concentrations, and accelerated life testing chronic estimation procedures. The acutely lethal concentrations (ALC) resulting in 50% mortality at 96 h (96-h ALC50s) were determined using linear regression and indicated that the three herbicides were toxic in the order of picloram acid > 2,4-D acid > clopyralid acid. The 96-h ALC50 values for rainbow trout were as follows: picloram, 41 mg/L; 2.4-D, 707 mg/L; and clopyralid, 700 mg/L. The 96-h ALC50 values for bull trout were as follows: picloram, 24 mg/L; 2.4-D, 398 mg/L; and clopyralid, 802 mg/L. Fractional estimates of safe concentrations, based on 5% of the 96-h ALC50, were conservative (overestimated toxicity) of regression-derived 96-h ALC5 values by an order of magnitude. Accelerated life testing procedures were used to estimate chronic lethal concentrations (CLC) resulting in 1% mortality at 30 d (30-d CLC1) for the three herbicides: picloram (1 mg/L rainbow trout, 5 mg/L bull trout), 2,4-D (56 mg/L rainbow trout, 84 mg/L bull trout), and clopyralid (477 mg/L rainbow trout; 552 mg/L bull trout). Collectively, the results indicated that the standard surrogate rainbow trout is similar in sensitivity to bull trout. Accelerated life testing procedures provided cost-effective, statistically defensible methods for estimating safe chronic concentrations (30-d CLC1s) of herbicides from acute toxicity data because they use statistical models based on the entire mortality:concentration:time data matrix.

Mercury balance analysis

International Nuclear Information System (INIS)