The first-year results establish a baseline-monitoring program for the Devils Lake and Red River basins, officials said.
"In the board's view, the results presented in the summary report should not be used to draw any definitive conclusions at this time," the commission's authors said in a statement.
The program's objective is to analyze the potential for transfer of species that might exist in Devils Lake but not in the Sheyenne River, Red River or Lake Winnipeg.
Previous studies focused on fish parasites and pathogens, phytoplankton, zooplankton, aquatic macrophytes and terrestrial plants.
The state of North Dakota built an outlet from Devils Lake to the Sheyenne River to help alleviate flooding problems in the Devils Lake basin. Since it started operating in 2005, the $28 million outlet has pumped about 100 million gallons of water into the Sheyenne, or the equivalent of less than one inch from the 136,000-acre lake.
The second year of the sampling program is under way. The third year will be conducted in 2008-09.
A risk assessment will be performed after the conclusion of the third year.
The sampling program is part of a bi-national effort developed after a 2005 statement on "Devils Lake Flooding and Ecological Protection" by the U.S. and Canada, along with the states of North Dakota and Minnesota and the province of Manitoba.
Here is a summary of the 2006 baseline results:
-- Fish from all sites in Canada and the U.S. did not show clinical signs of disease from bacteria.
-- No evidence of viral infection in the U.S.; two of 60 walleye from Canada with a common skin cancer and one of 60 with an iridovirsus.
-- Nine parasites detected in Devils Lake; 28 in the Red River Delta.
-- Two parasite taxa found in Devils Lake (gyrodactylus hoffmani and epistylis) have not yet been detected downstream in the U.S. or Canada.
-- A foreign and invasive parasite, the Asian tapeworm, recently has colonized the Red River Delta from an unknown source.
-- Histopathology of fish from the Red River Delta show evidence of a wide variety of parasite-induced lesions on a variety of tissues, as would be expected. However, a relatively high incidence of lesions in the heart of walleye is of concern.
-- Whirling disease was not detected in Lake Whitefish collected from Lake Winnipeg.
Previous studies were conducted in 2001-02 and in 2005.
In 2001 and 2002, a fish pathogen survey, conducted by the U.S. Fish and Wildlife Service Bozeman (Mont.) Fish Health Center, showed that "overall, fish appeared in good general condition," with no external or internal signs of bacterial kidney disease or other fish pathogens detected. The study included 180 fish from Devils Lake, 275 from the Sheyenne River and 83 from the Red River.
In 2005, more than 300 fish were collected from Devils Lake and tested for fish pathogens and parasites. No viral fish pathogens were detected
