James Larson

The USGS is investigating links between chloride concentrations in Great Lakes tributaries as a catalyst for Harmful Algal Blooms (HABs).

Harmful algal blooms (HABs) are a significant environmental concern due to their potential effects on health, ecosystems, and economies. Algal toxins, which are toxic compounds produced by certain species of cyanobacteria and algae, are commonly linked to these blooms. It's important to note that algal toxins can still be present even when a bloom is not visible, highlighting the need for ongoing...

Managing harmful algal blooms in the Great Lakes requires understanding the roles of nitrogen, phosphorus, and micronutrients, emphasizing a comprehensive approach beyond just phosphorus reduction.

Cyanobacteria (a.k.a. blue-green algae) are photosynthetic bacteria that occur in a wide array of terrestrial and aquatic habitats. In freshwaters, cyanobacteria sometimes form extremely dense populations that are termed blooms or harmful algal blooms (HABs). When forming blooms, cyanobacteria cause a variety of environmental issues, but one of the most important is the production of compounds (i...

Between 1902 and 1932, it is estimated that 22.7 million metric tons of copper-rich rock were processed in mills near Gay, MI, near Lake Superior. Waste rock from this process (so-called stamp sands) was deposited into a pile adjacent to the Lake Superior beach. Since 1932, these stamp sands have eroded from the original pile and along the shoreline to the south and west (Kerfoot et al. 2021)...

Harmful algae blooms can produce cyanotoxins that are harmful to humans, pets, livestock, and ecosystem health. Harmful algae blooms are a frequent occurrence in the Great Lakes, particularly in Lake Erie and Lake Michigan at the mouths of the Maumee and Fox Rivers and are partially caused by an excess of nutrients such as nitrogen and phosphorous in the water column.

Cyanotoxin concentrations that exceed World Health Organization’s drinking water guidance were observed in ~50% of samples taken during bloom events at Lake Kabetogama in Voyagers National Park. Lake Kabetogama is part of a large lake complex that includes other connected lakes, outflows of which are regulated by man-made dams. Here, we are exploring whether dam management could influence the...

The team develops advanced methods to study factors driving algal toxin production, how and where wildlife or humans are exposed to toxins, and ecotoxicology. That information is used to develop decision tools to understand if ​toxin exposure leads to adverse health effects in order to protect human and wildlife health.