Nationwide residues of organochlorine pesticides in wings of mallards and black ducks.

Nationwide monitoring of organochlorine pesticides in wings of more than 24,000 mallards and black ducks bagged during the 1965 and 1966 hunting seasons showed DDE to be the predominant residue, followed in order by DDT, DDD, dieldrin, and heptachlor epoxide. Residues were generally highest in wings from the Atlantic and Pacific Flyways, and lowest in the Central Flyway. DDE was reported for every State and was notably high in wings from New Jersey, Mas.~achusetts, Connecticut, Rhode Island, New York, Pennsylvania, Alabama, California, and Utah. Dieldrin residues were prevalent in wings from Arkansas, Texas, Utah, California, and several States in the Atlantic Flyway. Introduction Nationwide monitoring of organochlorine pesticides in wings of wild mallards and black ducks was initiated by the Bureau of Sport Fisheries and Wildlife in late 1965 as a segment of the National Pesticide Monitoring Program. Findings reported here are based on chemical analyses of wings from more than 24,000 ducks bagged during the 1965 and 1966 hunting seasons. The data provide base readings from which future trends in residue levels can be measured, and they permit geographic comparisons of residues. Wing monitoring is scheduled hereafter at 2to 3-year intervals. A full description of the Bureau's monitoring commitments has been given by Johnson, Carver, and Dustman (5). The decision to monitor mallard and black duck wings was based on several factors: (a) The combined range of the two species covers the continental' United States, the mallard being relatively abundant in all but the Eastern States where the black duck predominates; (b) Wings were readily available as a byproduct of an established I PatuxeN Wildlife Research Center, Bureau of Sport Fisheries and Wildlife, U.S. Department of the Interior, Laurel, Md. 20810. nationwide survey of waterfowl productivity wherein each fall cooperating hunters mail the Bureau tens of thousands of duck wings for biological examination; and (c) Dindal and Peterle (3), using DDT, ring-labeled with chlorine-36, to study DDT dispersion' in a marsh ecosystem, found highly significant correlations in 104 captive mallards and scaup ducks between DDT residues in wings and those in breast skin, kidney, breast muscle, uropygial gland, adrenal gland, pancreas, brain, gonads, liver, and thyroid. The average level in the wings was essentially equal to the median level in the above body parts; it was approximately twice that :n breast muscle and about one-eighth that in the urotgial ~~. A The monitoring methodology was successfully tested in early 1965 with wings from mallards and black ducks taken in New York and Pennsylvania during the fall of 1964, as reported by Heath and Prouty (4). Findings based on analyses of 36 "'pools" of wings, each pool composed of 25 defeathered wings chopped and blended into an homogenate, indicated that organochlorine residues were present in all pools and that levels of DDE tended to be higher in wings of adults than in those of immature birds. Wings were analyzed in pools rather than individually to increase the precision of estimates of average residue levels from a fixed number of analyses. Variability of residue levels among replicated pools indicated that pool size should not be reduced from 25 wings.