A unique species of spiny water fleas have made a new home in Wisconsin waters, the Wisconsin Department of Natural Resources announced Tuesday.
After sampling approximately 65 Wisconsin lakes looking for the fleas, UW-Madison zoology graduate student Pieter Johnson was prepared to give up his search when he discovered the zooplankton in the Gile Flowage, near Lake Superior.
What separates these animals from other fleas in North America are their long, spiny hooks constituting between two-thirds and three-fourths of their half-inch bodies, according to Ron Martin, invasive species coordinator for aquatic species of the DNR.
\One nasty thing about this critter is because it's so spiny, it's really hard for small fish to eat,"" Johnson said. ""Either they can't actually get it in their mouth, or if they do, it could actually puncture their their intestines and cause internal bleeding.""
Because the spiny fleas eat smaller zooplankton and damage small fish, they disrupt the aquatic food chain, he said.
Fishermen of the Great Lakes have reported the zooplankton pose an additional burden, according to Stanley Dodson, UW-Madison zoology professor.
""Fishermen complained because when they would pull in their nets, these animals would stick to the nets ... they can slime up the nets and apparently they irritate your hands,"" he said.
The animals inhabit the Great Lakes and inland lakes of Michigan Minnesota and Ontario, Canada. Because Lake Superior and Lake Michigan border Wisconsin, Johnson said he expected they would have migrated to some Wisconsin waters. The fleas move between bodies of water by attaching to boats that have not been cleaned, Martin said.
To combat such migration Johnson said he plans to take ""a ring vaccination approach.""
""By determining which lakes are frequented by people who also use Gile, we're going to try to hit those lakes as well with ... educational awareness,"" he said.
Martin said he thinks it is crucial boaters clean their boats before moving to other bodies of water.
While the fleas undoubtedly affect the food chain, Dodson said their overall damaging effects remain a mystery.
""I think we're a little unsure about how big an affect [spiny water fleas] had,"" he said.
