According to WDIO (Duluth), UMD researchers have been collecting samples to determine the likelihood of algae growth in Lake Superior waters. The goal of the faculty/student team is to discover how much human action (agriculture, urban growth, industrial use) is driving potentially harmful nutrient levels in the lake.
In July, UMD senior Shannon McCallum and assistant professor Ted Ozersky took samples from the shores of Leif Erikson Park in Duluth, MN. The team dove with wetsuits to procure their experiment: a landscaping tile with rows of clear cups, all of which had been diffusing nitrogen or phosphorus, or both, into the lake for a period of four weeks. The samples will be taken back to the lab to be frozen, dried, and weighed.
Ozersky told WDIO that the goal was to let algae grow in the cups for a month. “We’re trying to see which of these nutrients will stimulate the growth of algae on the lake bottom.”
This process was repeated at nine different locations on Lake Superior’s northern and southern shores. They were placed close to agricultural, urban, and industrial sites so they could measure human impact from things like fertilizer, stormwater runoff, or sewage. Ozersky and McCallum will be studying a variety of data to determine what nutrients are most important to manage to prevent harmful algal blooms from forming.
While some algae growth is normal and healthy, imbalanced nutrient levels and water temperatures can lead to large-scale problems. Look no further than Lake Erie’s consistent problems with algal blooms to see the consequence: they’ve been indicated in large-scale marine wildlife deaths, shellfish poisonings, and increases the risk of non-alcoholic liver disease death.
The study is being funded by a UMD biology grant, and constitutes McCallum’s summer research project.