Fish and Wildlife Advisory News - June 2003

Recent Advisory News

Current Events, News and Journal Articles

• Nutritional factors may modify the toxic action of methyl mercury in fish-eating populations - Clinical cases of methyl mercury poisoning have been reported dating back to the 19th century. Several catastrophic outbreaks of mercury poisoning occurred in the mid-20th century when treated seed grain was mistakenly used to prepare homemade bread. The largest outbreak occurred in rural Iraq in the 1970s. Human poisonings also occurred in Japan due to the release of methyl mercury into fresh and marine ocean water. The most severe outbreak occurred in the area of Minamata Bay: where methyl mercury was discharged into the bay and rapidly accumulated in the aquatic food chain to such a degree that residents who consumed fish were severely poisoned. Currently, human exposure to methyl mercury occurs principally from consumption of fish and sea mammals.

  Source: Clarkson, T.W. and J.J. Strain. 2003. Nutritional factors may modify the toxic action of methyl mercury in fish-eating populations. J Nutr 133 (5): 1539S-43S.

• Perceptions of recreational fishing boat captains: knowledge and effects of fish consumption advisories - The impacts of freshwater fish consumption advisories on recreational and subsistence fishing, have been studied extensively. In contrast, little attention has focused on organized recreational fishing, from party and charter boats, and particularly for marine fish. The authors surveyed 93 New Jersey boat captains to determine their knowledge about fish consumption advisories; whether, in their opinion, clients knew of fish consumption advisories; and whether they believed advisories had an effect on recreational fishing and their businesses. Advisories were ranked by captains as having a moderate influence on the success of their business, less so than the number of fish caught, strength of the economy, overfishing by commercial boats, and management regulations.

  Source: Burger, J., B.B. Johnson, S. Shukla, and M. Gochfeld. 2003. Perceptions of recreational fishing boat captains: knowledge and effects of fish consumption advisories. Risk Anal 23 (2): 369-78.

• Total mercury and methylmercury levels in fish from hydroelectric reservoirs in Tanzania - Total mercury (THg) and methylmercury (MeHg) levels were determined in fish species representing various tropic levels in four major hydroelectric reservoirs (Mtera, Kidatu, Hale-Pangani, Nyumba ya Mungu) located in two distinct geographical areas in Tanzania. Fish mercury levels ranged from 5 to 143 ppb (mean 40 ppb wet weight) in the Mtera Reservoir, and from 7 to 119 ppb (mean 21 ppb) in the Kidatu Reservoir .The lowest THg levels, in the range 1-10 ppb (mean 5 ppb), were found in fish from the Nyumba ya Mungu (NyM) Reservoir, which is one of the oldest reservoirs in the country. Fish mercury levels in the Pangani and Hale mini-reservoirs, downstream of the NyM Reservoir, were in the order of 3-263 ppb, with an average level of 21ppb. These THg levels are among the lowest levels reported in freshwater fish from hydroelectric reservoirs. The authors believe that Tanzanian reservoirs are relatively clean and have not been significantly impacted by mercury contamination from natural or man-made sources.

  Source: Ikingura, J R and H. Akagi. 2003. Total mercury and methylmercury levels in fish from hydroelectric reservoirs in Tanzania. Sci Total Environ 304 (1-3): 355-68.

• Fish May Fight Pregnancy Depression Risks - A recent study reported that fish consumption may help pregnant women avoid depression both before and after childbirth. Seafood--especially tuna, herring, salmon and sardines -- contains omega-3 fatty acids, which previous studies have shown counters depression and protects against heart disease. The federal government has warned pregnant women about eating certain kinds of fish because of mercury contamination, but its recommendations still encourage eating up to 12 ounces a week of a variety of species. The new study based on an analysis of 11,721 British women found that the more omega-3 fatty acids a woman consumed in seafood during the third trimester, the less likely she was to show signs of major depression at that time and for up to eight months after the birth. Rates of depression in women with the highest seafood intake were about half that of women with the lowest seafood intakes.

  Source: Ritter, Malcolm. May 21, 2003. Fish May Fight Pregnancy Depression Risks. Associated Press.

• Oil spill in Massachusetts' Buzzards Bay nearly seven times larger than first reported - An oil spill in Buzzards Bay that has killed hundreds of birds and closed the region's shellfishing industry was almost seven times greater than first reported. The April 27 spill dumped 98,000 gallons, not the 14,700 gallons first reported by Bouchard Transportation Inc.. Massachusetts Gov. Mitt Romney proposed hiking fines for companies that spill oil or other toxic substances into state waters, including an extra $25,000 a day for those who knowingly make false or misleading statements. Buzzards Bay contains some of the state's best shellfishing areas, producing quahogs, soft-shell clams, scallops and oysters. More information is available at the Division of Marine Fisheries.

  Source: May 20, 2003. Oil spill in Massachusetts' Buzzards Bay nearly seven times larger than first reported. Associated Press.

• The effect of dietary vitamin E and C level on market-size turbot (Scophthalmus maximus) fillet quality - The quality of fish fillets is influenced by the level of antioxidants in the preslaughter diet. The authors conducted a study to determine the effects of different levels of vitamin E and C on the fillet quality of market-size reared turbot (Scophthalmus maximus). Turbot of a mean weight of 347 ( 20 g were divided into four groups and fed commercial turbot diets, supplemented with alpha -tocopheryl acetate (mg kg-1) and ascorbyl-2 monophosphate (mg kg-1) at the following dietary levels: 500/100, 1000/100, 100/1000, 100/100 respectively. Over a period of 15 weeks, fish were fed dietary supplements to satiation and reached a final mean weight of 916 ( 29 g. Alpha -tocopherol levels increased significantly (P<0.001) in tissue (i.e. muscle, liver, heart and kidney) of fish fed diets containing elevated levels of alpha -tocopheryl acetate. During ice storage, fillets of these fish showed significantly lower (P<0.001) levels of lipid oxidation, and significantly less (P<0.001) color deterioration. Increased dietary vitamin C did not have any detectable effect on fillet quality.

  Source: Ruff, N. , R. D. Fitzgerald, T. F. Cross, K. Hamre, and J. P. Kerry. 2003. The effect of dietary vitamin E and C level on market-size turbot (Scophthalmus maximus) fillet quality. Aquaculture Nutrition 9 (2):91-103.

• Determination of low concentrations of organochlorine pesticides and PCBs in fish feed and fish tissues from aquaculture activities by gas chromatography with tandem mass spectrometry - The authors report development of a sensitive and rapid multiresidual method for the determination of organochlorine compounds in fish feed and fish tissues. The method is based on automated off-line normal-phase liquid chromatography (NPLC) clean-up prior to GC-MS/MS. Analytes are extracted by refluxing in n-hexane and fats present in the hexanic extracts are removed by automated NPLC, using n-hexane and ethyl acetate as mobile phase. The authors evaluated both NPLC and acid digestion with sulphuric acid as clean-up techniques for the analysis of these kinds of fatty samples. The high efficiency in elimination of fats from the extracts together with optimised MS/MS detection leads to high sensitivity in the multiresidue determination of analytes. The developed procedure represents an improvement over current methodologies for the analysis of organochlorine compounds (OCs) in fatty samples. Use of the developed method to analyze fish feed and fish tissue samples revealed the presence of HCB, DDTs, and PCBs at ng g-1 levels.

  Source: Serrano, R., M. Barreda, E. Pitarch, and F. Hernandez. 2003. Determination of low concentrations of organochlorine pesticides and PCBs in fish feed and fish tissues from aquaculture activities by gas chromatography with tandem mass spectrometry. Journal of Separation Science 26 (1/2): 75-86.

• Polybrominated diphenyl ethers in influents, suspended particulate matter, sediments, sewage treatment plant influents and effluents, and biota from the Netherlands - Polybrominated diphenyl ethers (PBDEs) were analyzed in 133 samples of suspended particulate matter (SPM), sediments, sewage treatment plant (STP) influents and effluents, and in fish and mussels from various locations in the Netherlands. This research was part of a larger Dutch national study on estrogenic contaminants in the aquatic environment. Some PBBs were also analysed, but were not found in any of the samples at detectable levels. This study, PBDEs and PBBs were included because indications of long term effects on the balance of endocrine systems were reported in the literature. DecaBDE was not found at detectable levels in flounder, bream, and mussels. Bioaccumulation of decaBDE in these fish and shellfish samples appears limited. The authors concluded that at least a small part of the PBDE can pass through STPs.

  Source: Boer, J. de, P.G. Wester, A. van der Horst, and P. E. Leonards. 2003. Polybrominated diphenyl ethers in influents, suspended particulate matter, sediments, sewage treatment plant influents and effluents, and biota from the Netherlands. Environmental Pollution 122 (1): 63-74.

• Mercury-tainted rain befouls fish - N.C.'s air has too much of toxic metal - Rainfall along the East Coast and particularly in the Carolinas contains high levels of mercury that has made it unhealthy to eat fish from some rivers, streams, and lakes. Results of a National Wildlife Federation report found that 97 percent of rain samples analyzed exceeded the EPA's standard for mercury. Rainwater samples were collected from 1995 to 2001 as part of a national mercury-monitoring program. South Carolina’s rainwater samples averaged twice the EPA standard, while North Carolina;s averaged 2.7 times higher than the standard. The report also cited similar elevated mercury trends in 11 other states including Georgia and Florida.

  Source: May 31, 2003. Mercury-tainted rain befouls fish - N.C.'s air has too much of toxic metal. The Associated Press.

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For more information on EPA's Fish and Wildlife Contamination Program, contact: Jeffrey Bigler at US EPA, 1200 Pennsylvania Ave., NW (4305), Washington, DC 20460; email: bigler.jeff@epa.gov.