A Small Flea Goes a Long Way
With all of the tropical, warm destinations on our diving lists, it can be easy to forget about the health of the water in our own backyard- the Great Lakes.
A new survey, conducted by the U.S. Geological Survey, has revealed that many of the major changes in Lake Huron's food web over the last decade are the result of the minute 'spiny water flee'. The arrival of this invasive species has caused a shift in balance of the lake's predatory consumption: the consumption of prey by invertebrates, like the tiny flea, has surpassed the consumption by bony fish.
In fact, in some of the studied regions, up to 78 percent of zooplankton -the planktonic basis of any marine food chain- were consumed by this one species of water flee alone!
"These findings shine a spotlight on the role of the invasive spiny water flea as a key predator on zooplankton in Lake Huron," explained Dr. David B. Bunnell, USGS scientist and lead author of the report. "Our study suggests that a better understanding of the role of invertebrates, and the spiny water flea in particular, is essential to fully comprehend the food web changes we've seen in Lake Huron since 2002."
Dr. Bunnell also attributed many of the dramatic changes in the Great Lakes' food chain to the arrival of this invasive predator, such as the collapse of several groups of salmon. It appears as though the predation of this seemingly harmless, tiny invertebrate has fish populations 'flea-ing' for flea-free waters.
