The U.S. Army Corps of Engineers released a Finding of No Significant Impact for its Environmental Assessment for adaptively managing predation on Caspian terns in the Lower Columbia River Estuary. Based on the FONSI, no action will be taken to manage predation.
The EA reviewed new activity by predator birds, primarily glaucous-winged/western gulls, a hybrid species on East Sand Island.
"We received about 80 responses during our comment period, most of which were concerned about the possibility of the Corps removing up to 150 gulls," said Joyce Casey, the Corps' chief of Environmental Resources Branch. "We also received new research findings during our analysis that showed it was very unlikely the terns would leave East Sand Island for new habitat farther upstream."
Natural Resource managers were concerned the terns may move farther upstream for nesting habitat, which would increase predation on juvenile salmon and steelhead, so data from recent years was studied to determine the likelihood of such a move.
"The purpose of the Environmental Assessment was to analyze the consequences of our proposed actions on juvenile salmonids," said Cindy Studebaker, a Corps fish biologist. "We were able to use results from recent studies to show our assumptions based on past research wasn't complete."
The Corps will continue to monitor East Sand Island and the other new tern habitats it constructed as it continues to implement the Caspian Tern Plan, a group of documents created by the U.S. Fish and Wildlife Service and the Corps in 2006. An inter-agency adaptive management team began discussing the effectiveness of the plan in 2012 and will offer recommendations on any new actions needed. The interagency team is made up of biologists and researchers from the Corps, U.S. Fish and Wildlife, NOAA Fisheries, and Bonneville Power Administration.