DDT, Chlordane, Toxaphene and PCB Residues in Newport Bay and Watershed: Assessment of Hazard to Wildlife and Human Health - Reviews of Environmental Contamination and Toxicology - page 91

The recommendation of the panel is reproduced below from the NAS ( 1972 )
summary.
The DDT measured in the terns and in scraps of fi sh cast from their nests on Great
Gull Island was not reported to have any effect on the terns. However, as detailed
below, the breeding failure of ospreys along the Connecticut coast and on nearby
Gardiner Island were clearly established in other studies. The implied assumption in
the panel's recommendation is that the ospreys would be eating the same fi sh with
the same level of residues found on Great Gull Island, and therefore that level was
clearly toxic. What the summary didn't say was that the ospreys tend to feed along
the coast and up the estuaries, resulting in a DDT exposure quite different from that
of the terns. For example, osprey feeding patterns at a location further north were
described by Greene et al. ( 1983 ). One could conclude from this and other studies
that ospreys often catch fi sh from fresh or brackish water and, therefore, may not
have been the best avian species for assessing the reproductive effect of DDT
residues in marine fi sh. Fish from the nearby Connecticut River had much higher
residues of DDT than the fi sh cast from tern nests on Great Gull Island.
Henderson et al. ( 1971 ) reported 0.85-3.27 ppm total DDT in fi sh collected from
the Connecticut River in 1968 and 1969. In addition, Ames and Mersereau ( 1964 )