AWRI researchers studying phosphorus, nitrogen in Spring Lake
Researchers from Grand Valley State University's Annis Water Resources Institute are conducting a series of experiments in Spring Lake to provide local authorities with a recommendation about how to best treat the lake to prevent harmful algae blooms.
Researchers have placed an array of containers on a rack in the lake in order to determine whether nitrogen, phosphorus, or a combination of both is controlling algal growth. Results of the testing are expected to be presented to the lake board in late fall of 2017.
"We are testing the phosphorus and nitrogen levels against a control to see what factor is limiting the growth of algae in Spring Lake, and provide the appropriate recommendations to the Spring Lake Lake Board," said AWRI director Alan Steinman. "We want to make sure that the management practices they implement are targeted to address the appropriate nutrient, to reduce the potential for toxic blue-green algae blooms."
Steinman said that despite previous treatments of the lake bottom with aluminum sulfate, phosphorus entering the lake from the surrounding watershed areas and the internal release of phosphorus from the lake sediment may be so high that nitrogen levels are now either the limiting factor in algal growth or co-limiting (with phosphorus) the growth of algae.
"It's important to know if nitrogen is the limiting factor rather than phosphorus because that's a whole different management strategy," Steinman said.
Nitrogen limiting may be a more common problem than most lake managers realize, Steinman said.
"In a lot of areas, the focus is almost entirely on managing phosphorus loading," he explained. "We are exploring if they should be focusing on nitrogen as well."
The research project is part of the dissertation research of Xiaomei Su, a doctoral candidate from Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences (NIGLAS). Su is studying at AWRI for one year as an exchange student. While at AWRI, she will be working in Steinman's lab conducting experiments and assisting with field work.
Steinman said he is grateful to the homeowners on Spring Lake, who have been cooperative and supportive of past research activities, and who have allowed his team access to their dock to conduct these current experiments, as well as to Progressive AE, a consulting firm in Grand Rapids, who have been partners in their Spring Lake research.
The research is being funded in part by the R.B. Annis Educational Research Fund.
For more information, visit gvsu.edu/wri