When my life is in balance, I just know it. There is no formula. The mix of what creates my personal balance changes over time and is likely not the same way you find balance. Hopefully, if some elements of my life become too demanding, I can make adjustments and put life back into balance. Ecosystems are like that. They are dynamic, like our lives. Sometimes there are more plants being eaten this year than last by the deer population, or several young trees die because of the drought. But somehow the ecosystem mends itself. It evolves with new plants and animals and finds a new balance. And the cardinals and the foxes and frogs still come back to the garden.

But sometimes balance cannot be regained because of a shock to the system than is greater than before. Something major is added or taken away. The prairie becomes an office building and the landscape changes dramatically. The plants that fed the deer and provided nesting places for the birds are no longer there. Sometimes an ecosystem endures such dramatic change that it cannot mend itself. A quote on the World Wildlife Fund website defines ecological balance as “a state of dynamic equilibrium…subject to gradual changes through natural succession.”

But sometimes the change is not gradual and the system cannot adapt. It reaches a tipping point and changes completely.

Lake Michigan Ecosystem: Asian Carp Threaten the Balance

Jerome McDonnell and I talked to two experts on WBEZ’s Worldview to find out whether the hype regarding the threat of Asian carp to the Great Lakes ecosystem is warranted. The answer was a resounding “yes!” Fortunately, our experts—Kim Rice of Friends of the Chicago River and Jared Teutsch of the Alliance for the Great Lakes—have been working hard to prevent Asian carp from reaching the Chicago River and entering into Lake Michigan.

The reason is that the aquatic food chain in Lake Michigan is already so weakened by other invasive species, like the zebra mussel, that adding a voracious plankton feeder such as Asian carp to the mix will likely push it over the tipping point. Meaning? Most fish other than the carp will die. Asian carp will devour the plankton that is the bottom of the food chain, leaving very little for the other fish to eat. Not only that, Asian carp reproduce quickly and are exceptionally fast swimmers. In the Great Lakes ecosystem, Asian carp will be the fittest, fastest, and fattest. They will also be lonely because few other fish will be able to survive once the carp move in.

Jared, the Alliance’s water policy advocate says, “It is a myth that we have dealt with other invasive species in Lake Michigan successfully.” Because of the loss of plankton, whose population has been decimated by zebra mussels, the “Lake Michigan ecosystem is at a tipping point already.” Could we bring in a larger predator to eat the Asian carp? If only. Unfortunately, the carp swim too fast and have all the other advantages already listed. So a big predator fish would more likely eat the slow, easy-to-catch smaller fish rather than the carp and the invader would still reign supreme. If the Asian carp gets into Lake Michigan and the rest of the Great Lakes, it would likely devastate the $7 billion fishery industry.

Fortunately, experts have not found evidence of carp in Lake Michigan yet. But the Chicago River, which is upstream of where the carp have been seen further south in the Illinois River, is the most likely gateway to the Great Lakes. Several state and federal agencies, municipalities, and other groups, under the umbrella of the Asian Carp Regional Coordinating Committee, are doing all they can to prevent the carp from migrating north to Chicago. These measures have included installing an electric barrier between the two rivers.

Kim indicates that the most effective solution, currently being advocated by several agencies, would be to completely separate the Chicago River from the Illinois River. “This would not only keep the carp from coming upstream and ruining the Chicago River’s ecosystem, it will enable commercial development and recreational uses to continue to improve on the river.”

So is separation going to happen? As with most projects of this scale, the decision is being analyzed and will take time. But let’s hope that it will happen soon. According to a recent report by the Great Lakes Commission [pdf], Asian carp have been spotted as close as 5 miles away from Lake Michigan.

For a full article and other resources on the misconceptions regarding the Asian carp dilemma, see the full EcoMyth here. Additional information can also be found on the websites of our experts: Alliance for the Great Lakes and Friends of the Chicago River.

—As part of the Worldview/EcoMyths partnership, this blog also appears on the Chicago Public Radio page.

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