Oil spill's impact on loons, pelicans to be studied in Minnesota
Minnesota wildlife biologists now have the money they need to study the impacts of the 2010 BP Gulf of Mexico oil spill on the state's loons and pelicans.
Over the next two years researchers will check loon and pelican eggs, blood and tissue, and even the unusual mating growth knobs on pelican bills that fall off each summer. They'll be looking for the presence of toxic polyaromatic hydrocarbons, a byproduct of oil, and for potentially toxic Corexit, the dispersant used to treat the oil spill.
The U.S. Geological Survey will implant satellite transmitters and geolocators on several Minnesota loons to document their wintering grounds and foraging depths in the Gulf, where up to 80 percent of the state's loons spend their winters.
Samples will be taken from loons captured for the study and from any dead loons recovered on Minnesota lakes this summer and next.
"We just got the contract back today, and we hope to be in the field (fitting birds with transmitters) next week,'' Carol Henderson, DNR nongame wildlife program supervisor, told the News Tribune on Friday.
The project, proposed last winter, received $250,000 when the state Legislature approved budgets during the July special session. The money was approved by the Legislative and Citizens' Commission on Minnesota Resources from the state's profits on lottery sales.
Another $47,000 will be used from proceeds of state conservation license plates.
Minnesota wildlife biologists are particularly concerned about the potential long-term effects of the oil spill on common loons because most loons hatched in Minnesota in 2008 and 2009 would have been in the Gulf of Mexico during the catastrophic spill from the BP oil rig. That's because young loons don't migrate north until their third year.
And because loons don't mate until their fifth year, any major impact on one or two consecutive breeding years could have an impact on the total population.
"So far there's no red flag out there. They seem to have come back to Minnesota this year in numbers that look normal,'' Henderson said. "But it's going to be several years before the exposed loons would have become mating pairs, and that's when we'd expect to see any major decline."
Even adult loons that were in Minnesota and that avoided last summer's spill may be at risk. Because loons can dive 200 feet to find fish, they may have foraged for fish last winter on the Gulf floor where experts now say most of the oil from the spill has settled.
Young pelicans also spend a full year on their wintering grounds in the Gulf, so pelicans that hatched in Minnesota in 2009 would have been in the Gulf during the spill.
The study is a cooperative effort between the Minnesota Department of Natural Resources, Wisconsin Department of Natural Resources, U.S. Geological Survey, University of Minnesota, North Dakota State University and University of Connecticut.
If exposure to the oil spill is found to have reduced the overall number of Minnesota loons or pelicans, state officials may need to enact special conservation regulations and efforts.
Minnesota has about 12,000 loons, and their population has remained relatively stable over the past decade despite threats from shoreline development, lead poisoning from fishing tackle and collisions with boats. The state has about 32,000 pelicans, and their numbers have been increasing.
Officials now estimate about 250,000 birds of all species perished directly during the oil spill, which started April 20 and lasted through July 15, 2010, during which time more than 205 million gallons of oil is estimated to have spewed from the Deep Horizon offshore oil well.
Volunteer loon watchers and the public already have turned in 20 dead loons found along Minnesota waterways this summer that will be tested for contaminants, Henderson said. If you find a dead loon, please keep it and call the DNR at (218) 327-4518.