YELLOW BAY – The next time you drive along, boat across or dive into Flathead Lake, Shawn Devlin has a few things for you to keep in mind – some of them things that you cannot see with the naked eye.
Mysis shrimp, which many years ago turned the Flathead fishery on its head, now appear to be breeding twice a year and are showing up “where they are not supposed to be.” Nitrogen levels continue to rise dramatically. Algae that attaches to rocks along the shoreline is increasing.
Still, the largest freshwater lake west of the Mississippi is in good shape, Devlin told the Flathead Lakers at their annual meeting recently.
The lake ecologist at the University of Montana’s Flathead Lake Biological Station delivered the annual “State of the Lake” address to the group – the first time in decades it hadn’t come from former biological station director Jack Stanford, who retired last year.
His replacement, Jim Elser, also spoke to the Lakers, a citizens’ group founded in 1958 to work to protect the water quality of Flathead.
Elser told them about a University of Vermont study that showed a one-meter increase in water clarity corresponded with a 3 percent increase in home values, and a 37 percent increase in seasonal home values. A one-meter decrease in water clarity has the opposite effect, and also results in job losses and reduced tourism spending.
“We care about our property values and our businesses,” Elser said, “but the real reason we care is to pass on our clean lake to our children and grandchildren.”
Devlin’s biggest concerns for Flathead are the threat of new aquatic invasive species introductions, and the potential for a catastrophic event such as an oil train spill on railroad tracks that run along the Middle Fork of the Flathead River.
“Even though we have an amazing template to work with, we could still mess it up,” Devlin said.
Some of the items he touched on:
• Data from the mid-lake monitoring station indicates the lake is not warming up, but it could be a different story in sheltered bays.
• Phosphorus levels have been stable since 1990, but nitrogen has “drastically increased since 1996 and is still increasing at all depths.” The sources of atmospheric deposits of nitrogen are located outside the Flathead watershed, making it more difficult to change the trend.
• Septic system problems may be responsible for the increase in periphyton, the algae attached to rocks along the shoreline.
• Mysis shrimp numbers have been oscillating a great deal over the past 12 years, and are currently rapidly increasing. When that happens there is a lot of chlorophyll present, few zooplankton, and low primary productivity, a measure of the rate of algal growth.
Mysis are starting to inhabit shallower waters, including the photic zone, the surface waters that light penetrates. They shouldn’t be there, Devlin said, and the changes in distribution appear to indicate they are now breeding twice a year. That has been seen in other lakes, but only ones with a higher productivity than Flathead.
• Meantime, lake clarity is increasing. Clarity is measured with a Secchi disk, a tool developed more than 150 years ago that is lowered into the water until it is no longer visible. The depth where it disappears from view determines the clarity level.
Devlin said biological station researchers aren’t sure yet why Flathead’s clarity is on the rise.
The actual State of the Lake report is not issued until the “water year” ends on Sept. 30 and all the data the station monitors has been analyzed. Devlin, who is completing a post-doctoral research and teaching position at the station and is in charge of its water quality monitoring program, will soon join its faculty as a research assistant professor.
Other personnel notes at the station include the arrival of professor and entrepreneur Cody Youngbull, who hopes to manufacture environmental sensors he has invented that eventually may provide DNA detection of invasive species such as quagga or zebra mussels. Elser’s wife, Monica, has also been hired as education liaison, and the new director plans to add new scientists and fill new faculty positions.
“I can reassure you that all the things you love about the bio station will continue to happen,” Elser told the Lakers.
The biological station was established in Bigfork in 1899 by Morton Elrod, and moved to Yellow Bay in 1908. It is the second-oldest biological station in America.
Rusby and Liz Seabaugh were honored with the Lakers’ annual Stewardship Award for protecting more than 700 acres of wetlands, riparian areas and farm land along the Flathead River.
The conservation project was one of the first completed in cooperation with a fledgling partnership among private landowners, organizations and government agencies now known as the River to Lake Initiative.
The Lakers’ first-ever Education Award went to Polson third-grade teacher Gail Burghardt, who championed the organization’s Becoming Watershed Stewards student education program after Lakers Executive Director Robin Steinkraus approached the school district with it.
Steinkraus said Burghardt has mentored new third-grade teachers and written grants to provide a trunk of educational materials for each Polson third-grade classroom, rather than having six teachers share one trunk.
The program “includes interdisciplinary, hands-on classroom lessons and activities, and culminates in a field trip to the Flathead Lake Biological Station each spring,” Steinkraus said. Polson classes have participated for 19 years, and five schools in the watershed – reaching some 400 students annually – now offer the program.