Birds fish-eating

According to NAS, "Fish-eating birds should be protected if mercury levels in fish do not exceed 0.5 mg/g."... 

According to EPA, "The maximum acceptable concentrations of PCB in any sample consisting of a homogenate of 25 or more whole fish of any species that is consumed by fish-eating birds and mammals, within the size range consumed is 0.5 mg/kg on a net weight basis."... 

In field trials following multiple aerial applications of endosulfan for tsetse fly control in Africa over a 3-month period, residues of the compound in fish tissues decreased to low concentrations within 3 months after spraying. The fish tissue residues were still detectable after 12 months. Residue concentrations in fish-eating birds and crocodiles were similar to fish tissue residue levels endosulfan did not biomagnify in the food chain (HSDB 1999). 

PCBs have been implicated in the decline of certain populations of fish-eating birds, for example, in the Great Lakes of North America. Although their use is now banned in most countries and very little is released into the environment as a consequence of human activity, considerable quantities remain in sinks (e.g., contaminated sediments and landfill sites), from which they are slowly redistributed to other compartments of the environment. There continues to be evidence that PCB residues are still having environmental effects, for example, on birds and fish. 

Gilbertson, M., Kubiak, T., and Ludwig, J. et al. (1991). Great-Lakes embryo mortality, edema, and deformities syndrome (glemeds) in colonial fish-eating birds—similarity to chick-edema disease. Journal of Toxicology and Environmental Health 33,455-520. 

Prey fish are here defined as small, usually short-lived, finfish. In North American fresh waters, many are members of the cyprinid (minnow), percid (perch), and centrarchid (sunfish) families. Prey fish are widely distributed, common, and important in the transfer of MeHg to higher trophic levels, such as piscivorous fish and many fish-eating birds. MeHg concentrations in prey fish of uniform age are less... 

Fimreite N, Holsworth WN, Keith JA, Pearce PA, Qruchy IM. 1971. Methyl mercury in fish and fish-eating birds from sites of industrial contamination in Canada. Can Field Natural 85 2211-2220. 

Gilbertson M, Kubiak TJ, Ludwig JP, Fox G. 1991. Great Lakes Embryo Mortahty, Edema and Deformity Syndrome (GLEMEDS) in colonial fish-eating birds similarity to chick edema disease. J Toxicol Environ Health 33 455-520. 

Qrasman KA, Scanlon PF, Fox GA. 1998. Reproductive and physiological effects of environmental contaminants in fish-eating birds of the Great Lakes a review of historical trends. Environ Monit Assess 53 117-145. 

In a puzzling phenomenon, the insecticide did not stay where it was sprayed. In the five years between DDT s release for civilian use in 1945 and 1950, DDT used against flies in cow barns reappeared in cows milk. DDT was linked to fish-eating birds of prey that produced fewer or no young. Princeton, New Jersey, used 4.5 pounds of DDT per Dutch elm tree per year, and scientists found DDT in the tissue of dead birds and a nestling survival rate of only 44 percent. 

Diet (pg Hg/kg FW ration as methylmercury) Less than 20 for fish-eating birds 56... 

Van den Berg, M., F. Blank, C. Heremans, H. Wagenaar, and K. Olie. 1987. Presence of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in fish-eating birds and fish from the Netherlands. Arch. Environ. Contam. Toxicol. 16 149-158. 

PCCD/PCDFs have been found to be present in Arctic air samples, e.g. during the winter of 2000/2001 in weekly filter samples (particulate phase) collected at Alert in Canada. PCDD/PCDFs have been monitored since 1969 in fish and fish-eating birds from the Baltic. The levels of PCDD/PCDFs in guillemot eggs, expressed as TEQ, decreased from 3.3 ng/g lipids to around 1 ng/g between 1969 and 1990. Since 1990, this reduction seems to have levelled off and today it is uncertain whether there is a decrease or not. Fish (herring) show a similar picture. 

In the 1960s, organic residues (e.g. DDT, PCBs, methyl mercury) began to be detected in several species of shellfish, fish and fish-eating birds [1,2]. Since then, assessment of the bioaccumulation of chemicals has been considered decisive for determining the potential hazard and environmental risk it is regulated by various official organisations such as the OECD [3], EPA [4,5] and ASTM [6],... 

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