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Effect of Pesticide Use on Avian Reproduction, Klamath Basin Complex NWR
Date Posted: February 1, 2006The final draft report "Effect of Pesticide Use on Avian Reproduction, Klamath Basin Complex National Wildlife Refuge" was completed during 2005.
The objectives of this study were to
(1) determine the impact of pesticide use on avian reproduction by comparing reproductive success between birds foraging on pesticide treated and reference test sites (sites that are not known to be treated with pesticides),
(2) monitor avian dietary exposure to pesticides most likely to cause adverse affects by obtaining food samples brought to nestlings by parents,
(3) monitor avian blood serum and brain enzyme activity to indicate the occurrence of exposure to carbamate and organophosphate insecticides, and
(4) document any deaths or other adverse effects that may be related to pesticide applications on the refuge.
Tule Lake and the adjacent Lower Klamath National Wildlife Refuges (TLNWR and LKNWR) serve as key spring and fall staging and overwintering areas for Pacific Flyway migratory waterfowl, with more than 89 million goose and duck use days recorded in the refuges in 1988. The shortnose suckers (Chasmistes brevirostris) and the Lost River suckers (Deltistes luxatus), listed as endangered in 1988, inhabit Tule Lake (in TLNWR), habitat that is currently proposed critical habitat for the suckers. Lands on the refuges are leased to growers under requirements of the Kuchel Act, which provides for leasing of up to 22,000 acres. Crops currently grown include potatoes, onions, sugarbeets, alfalfa, and grains. More than 60 different pesticides are allowed on the lease lands, including some insecticides from the organophosphates, carbamate, and pyrethroid class.