^'«^4»^^ 



PESTICIDE-WILDLIFE RELATIONS 



The Bureau is responsible for obtaining defini- 

 tive information on the immediate and long-range 

 effects of pesticides on wildlife resources and for 

 assisting in the development of methods and mate- 

 rials that will assure effective pest control with the 

 greatest possible safety to man. wildlife, and the 

 environment. 



The universal distribution of persistent pesti- 

 cides is becoming increasingly noticeable, well 

 shown by the occurrence of residues in animals 

 collected at large, without reference to particular 

 pesticide treatments or programs. Animals 

 found dead after treatment with one chemical 

 often contain other chemicals. The effects of 

 nuiltiple contamination are now beginning to be 

 assessed. And ecological studies of specific areas 

 have shown residues throughout the environment, 

 including mud, water, soil, invei"tebrates. plants, 

 fish, insects, birds, mammals, and other materials. 

 The universality of the pesticide problem gives it 

 compelling concern. 



Some of the salient findings during 1964 are 

 recorded in the paragraphs which follow. For 

 more detailed information, the reader is referred 

 to the "Publications" section at the end of this 

 report. 



Pesticides in the Lake Michigan ecosystem. — 

 Kxplorations in tiie Green Bay area of Lake 

 Michigan l)y University of AVisconsin personnel 

 showed dramaticalh' tlie buildup in residues 

 through the food chain. Nine deep-water (33 to 

 96 feet ) mud samples on both the bay and lake sides 

 of the Door County peninsula averaged 0.014it: 

 0.005 ppm of DDT, DDE. and DDD on a wet- 

 weight basis. Wet-weiglit levels of the same com- 

 pounds in the crustacean Pentcpoi'eia ajjinis ran 



0.41 ppm at a depth of 90 to 100 feet in Ellison 

 Bay; 0.44 in old-squaw ducks; and 0.54 in white- 

 fish taken 5 miles off Bailey's Harbor in the lake. 



AVet-weight levels averaged 3.35 ppm in 13 ale- 

 wives taken bj- (and away from) herring gulls, 4.2 

 in alewife fertilizer oil, 4.52 in 10 chubs analyzed 

 as whole fish, and 5.60 in muscle tissue of 5 white- 

 fish. Xo correlation of these levels with age of 

 the fish was evident. 



Wet-weight residues of the three compounds in 

 the brain, breast muscle, and body fat, respectively, 

 of three juvenile old-squaw ducks collected in mid- 

 winter averaged 0.74±0.02, 2.03±0.04, and 72.9 

 ±8.8 ppm. For two adults, these values were 

 1.67±0.12, 6.33±1.48, and 188.0±11.16. Residue 

 levels in two juvenile ring-billed gulls collected 

 during the nesting season were quite similar to 

 those of the young ducks: 0.72 ±0.14, 3.6 ± 1.3, and 

 77.9±24.7 ppm; but those in two adult ring-billed 

 gulls were considerably higher: 7.1 ±0.6, 28. 0± 

 4.8, and976±179 



Twelve seemingly healthy adult herring gulls 

 collected on nesting islands had 20.8±2.1 ppm of 

 the three compounds in tlieir brains, 98.8± 9.2 in 

 breast muscle, and 2,441 ±334 in bodj- fat. In this 

 locality, young herring gulls appear to attain the 

 same general residue levels as the adults, at least 

 by the time the birds become yearlings. 



Door County, offshore of which these residues 

 are reported, lias been using about 70,000 pounds 

 of DDT a year. Insecticide use along the eastern 

 side of Lake Michigan probably shows wide 

 variation north to soutii. It is verj- likely lower 

 than in Door County to the north and heavier to 

 the south because of the large orchard industry 

 in that region. 



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