Long-lasting chemical contaminants may still be persisting in the Chesapeake Bay region, but the pollutants have had no significant effect on the world’s largest breeding population of ospreys, according to a report from the U.S. Geological Survey (USGS).
While the three-year study found some residue of pesticides and industrial chemicals in the Bay’s tidal waters, fish, osprey eggs and osprey chicks, researchers did not find a connection between the fish hawk’s exposure to the chemicals and its success in the Chesapeake region.
“Osprey populations are thriving almost everywhere in the Chesapeake,” Rebecca Lazarus, a researcher at the USGS’ Patuxent Wildlife Research Center and the lead author of the report, said in a release. “We found them nesting in some of the most highly contaminated areas in the Bay and we did not find any relationship between contaminants and their nests' productivity.”While it's true that the Bay, as indeed most of the world, is still contaminated with a large number of long lasting contaminants, including DDT, PCBs, and mercury, Ospreys are not full time residents in Maryland. Come October, they leave for various fishing grounds in the Caribbean, Central and South America, only to return again in March to breed. Depending on where they chose to live in their "time away", they could either getting more pollutants (South and Central American countries are not noted for their high environmental standards) or less pollutants in their diet than in the Bay, confusing the results of a study that tries to tie their success to pollution in the Bay.
Widespread use of DDT in the mid-twentieth century caused the Bay’s osprey population to fall to fewer than 1,500 pairs before the pesticide was banned in the United States in 1972. Close to 10,000 pairs of osprey are expected to nest in the Chesapeake region this year.