Washington, DC — The continent’s principal breeding grounds for migratory waterfowl is under growing threat from agricultural pollution, according to a new federal government report posted today by Public Employees for Environmental Responsibility (PEER). Researchers found that as many as half of the breeding hens and high numbers of hatchlings are at immediate risk.
The December 2018 U.S. Fish and Wildlife Service (FWS) report entitled “An Evaluation of Agricultural Tile Drainage Exposure and Effects to Wetland Species and Habitat within Madison Wetland Management District, South Dakota” details how “agricultural tile drains in South Dakota can discharge concentrations of nutrients, pesticides, salts, and selenium that exceed water quality benchmarks and are likely harmful to wildlife.”
The authors cite “the recent expansion of the use of agricultural tile drainage within WPA [Waterfowl Protection Areas] watersheds” and write that “we frequently observed unabated direct discharges of tile effluent into wetlands and road ditches and the use of tile risers to drain row-crop fields.”
One big worry is increasing bio-accumulation of selenium leading to “abnormal embryonic development, decreased hatchability, reduced growth, reproductive failure, and mortality.” The report concludes that “selenium-induced reproductive impairment is likely already occurring, and that a worst-case scenario of 53% of all hens being affected cannot be ruled-out statistically.”
Besides selenium, discharges contain other nutrients, such as phosphorus and nitrates, as well as “estrogens, pathogens, veterinary antibiotics” and other compounds. The report finds that “In addition to nutrients, 31 different pesticide compounds were detected… at concentrations above water quality benchmarks included two herbicides (atrazine and metolachlor) and three neonicotinoid insecticides…”
“This report documents a witch’s brew of chemicals pulsing at increasing volumes into the wetlands that are home to more than half of North American migratory waterfowl,” stated PEER Executive Director Jeff Ruch, referencing the 4.4 million acres of wetlands in the Prairie Pothole Region of the Dakotas. “Modern American agriculture is literally killing the goose population that lays the golden egg.”
The report also makes clear that conditions will continue to deteriorate because “Pollution from agricultural tile drainage in South Dakota is considered nonpoint source and is unregulated by state or federal agencies responsible for protecting water quality.” It concludes that “Given that voluntary measures under the CWA [Clean Water Act] have not been as successful as CWA regulations to address point source pathways, excessive nutrients are not likely to be adequately addressed without the addition of enforced regulatory options.” However, the Trump administration has proposed a massive rollback of wetlands protections under the Clean Water Act.
“Everyone acknowledges the importance of the Prairie Potholes but we lack a coherent strategy for protecting them,” Ruch added, pointing to the selenium build-up that caused mass bird die-offs in California’s Kesterson Reservoir in the 1980s. “A repeat of Kesterson in the Dakotas would be an eco-catastrophe.”
###
Read the FWS Prairie Potholes study
Revisit the Kesterson selenium disaster
View FWS Prairie Potholes web-center
Look at Trump threat to protecting Prairie Potholes
Examine weak protections for Prairie Pothole
See how growing pollution of Prairie Potholes has been treated as a dirty secret