Organochlorine residues in adult mallard and black duck wings, 1981-1982.

Ten organochlorine compounds were identified in pools of black duck (Anas rubripes) and mallard (A. platyrhynchos) wings from the 1981-82 hunting season. Most organochlorine compounds occurred very infrequently. Among those compounds positively identified by mass spectrometry, DDE and, secondarily, PCB had the highest frequencies of occurrence. Other compounds, positively identified and occurring less frequently, included DDT, DDD, DDMU, dieldrin, heptachlor epoxide, trans-nonachlor, cis-chlordane and mirex. Compounds looked for but not positively identified include oxychlordane, cis-nonachlor, endrin, hexachlorobenzene and toxaphene. PCB levels in black duck wings declined between the 1979-80 and 1981-82 collections. PCB levels in black duck wings from the northern region of the Atlantic Flyway were higher than those in wings from the southern region. Mean DDE residues in mallard wings declined between collections and differed among flyways and regions. PCB levels in mallard wings differed only among flyways and regions.