Trout Lake Food Web Changes→

UW-Madison Center for Limnology:

“The story in Trout Lake played out in three acts. From 1981, when data collection began, to 2006, the Trout Lake ecosystem was humming along in a state scientists often refer to as “equilibrium” with its food web dominated by three main characters.

Tiny, free-floating crustaceans called zooplankton formed the base of the food web and ate large quantities of algae, which helped keep the water clear. A small, silvery species of prey, or “forage,” fish called cisco ate the zooplankton. And lake trout, the large, apex predator that gave the lake its name, ate the cisco.

During this “first act,” cisco dominated the food web. They were the more numerous of the two fish species, which is the common arrangement in predator/prey dynamics, and their high numbers kept zooplankton populations in check.”

Jake Walsh: Learning about Consequences of Non-indigenous Species→

UW - Center for Limnology

“For reasons we don’t yet completely understand, nutrients concentrations have been lower and beach conditions have actually been better since spiny water flea showed up in Lake Mendota. Somehow, there seem to be fewer nutrients available to cyanobacteria to feed really big blooms, which means we likely have as much control over preventing summer blooms now as we did before the invasion by reducing nutrient concentrations in the lake.

Getting to the bottom of these new findings can help us get more of something we enjoy in Lake Mendota – good water quality. Of course it’s unlikely that we’re done making mistakes, particularly when it comes to invasive species. Invasive zebra mussels were detected in Lake Mendota in 2015, six years after spiny water flea’s detection. We’re already learning more about both zebra mussels and Lake Mendota as they grow in abundance and transform the lake bottom.

But, like the spiny water flea, there’s still that silver lining – mistakes teach. If we continue to study lakes carefully over long periods of time, we can uncover more about how they work and use that information in positive ways. And, just maybe, we’ll not only learn from these mistakes but also learn how to stop making them.”

Spiny Water Fleas and Green Water→

UW-Madison Center for Limnology

“The spiny water flea could be making Lake Mendota greener through eating algae-grazing Daphnia, compounding a problem that stems from manure and fertilizer run-off into the lake. It’s really difficult to understand when and where the spiny water flea will be abundant and have negative effects on ecosystems.”