A Break in the Great Lakes Food Chain
Recent research found phytoplankton in the Great Lakes fishery were not ingesting nitrate, one of their essential nutrients and a vital part of the fishery’s food chain. The fish that normally feed on phytoplankton were not following historic growth models while the phytoplankton were also consuming less carbon from the atmosphere.
Clarkson professor and limnologist Michael Twiss found nitrate remained plentiful throughout the fishery and hypothesized something was preventing them from eating.
“The phytoplankton are surrounded by food,” he says, “and yet they’re waiting for other nutrition.”
During his investigation, Twiss found invasive zebra mussels had been removing minerals, like iron, from the fishery. Phytoplankton must have metals to utilize nitrate.
After sprinkling trace amounts of metal (molybdenum), into water samples, Twiss found the phytoplankton quickly resumed eating the nitrate. He says uncovering such ecosystem details may help species adapt to environmental changes.
“It’s up to us to understand how ecosystems work,” Twiss says, “so we can predict what will happen in the future, and to manage for change.”