Something …fishy… in Lake Michigan? Pollution, Invasive Species, and Wildlife Identification

On May 10, 2014, the Calumet Scouts visited the Indiana Dunes in Indiana National Lakeshore near Cowles Bog.  Upon reaching the beach, we noticed a large fish swimming near the shore. Thankfully, it was not dead, and two Calumet Scouts waded into the lake to get a closer look. The fish was large, close to two feet long, and eight inches from dorsal fin to belly, quite possibly weighing upward of twenty pounds. It was a fairly uniform-colored gold-brown color, with a sort of cross-hatched pattern between the scales. There were no ulcers or deformities or abnormalities, and the fish felt smooth to the touch. What was strange about this huge fish was that it moved incredibly slowly, was so close to shore, and seemed to have some trouble avoiding the Scouts: it’s fairly common knowledge that most fish are extremely skittish and spook at anything that could be a predator, especially anything that splashes and makes sudden movements, which the scouts were definitely doing.

Up close and personal

Up close and personal

The good news: The fish we encountered was a common carp, not what we think of as an invasive Asian carp. The common carp was originally native to Europe and Asia, and was introduced to the Midwest in the 1800s as a game fish, whereas “Asian carp” were introduced in the 1970s as part of a plan to control weeds and parasites in US fish farms. While the common carp is currently listed by the Illinois Department of Natural Resources as an exotic species, the four species of Asian carp (grass carp, silver carp, bighead carp, and black carp) are codified as harmful invasive species. This is indicative of the fact that the common carp presents less of a real threat to the Great Lakes ecosystem than other Asian carp would. It is estimated that were the four contraband species of carp to infiltrate the Great Lakes, they would decimate the indigenous fish population causing severe damage (if not collapse) to the multi-billion dollar Great Lakes fishing industry. Asian carp are capable of jumping many feet out of the water (see youtube link: https://www.youtube.com/watch?v=tLmJjRqXDCo), which, in addition to allowing them to pass many locks’ electric shock fish-killing devices, but also makes recreation in affected areas dangerous, seeing as the carp become 10-20 pound projectiles when disturbed.

goodfish badfish

The bad news:  The fish we encountered was definitely not behaving normally. Since the site where we encountered the fish was within easy walking distance of Bailly Generating Station, a NIPSCO-run coal-fired power plant, my best guess at why the fish was unable to escape more quickly would be mercury contamination. Mercury acts as a neurotoxin, which means it can affect the nerves and muscles a fish would need to swim and react properly, and mercury is known to collect in the tissues of fish, up to a million times the concentration of mercury in the surrounding water. For this reason, seafood eaters on the Great Lakes are warned not to consume carp at all (while other fish can be consumed as often as weekly) due to potentially dangerous levels of mercury and PCB in the meat. And while Bailly Generating Station has technically never broken the EPA’s rules for mercury pollution control, it takes a very long time for mercury and PCB levels in a contaminated area to decrease to levels that are safe for humans or wildlife. Plus, as recently as 2012, the flow of effluent from Bailly Generating Station across the nearby beach was categorized by Nicole Barker of Save the Dunes as a “serious public health concern [that] should be unacceptable in the eyes of Indiana Department of Environmental Management and other regulatory agencies.” So, while we can rest assured that some protections are in place against industry’s potential to pollute the Great Lakes and the Indiana Dunes National Lakeshore, it is important to note that these protections are not always enough to guarantee the health of the surrounding ecosystem.

Given the fact that invasive species and water pollution currently cost the United States a respective $137 billion and $4.3 billion-plus  per year, it’s pretty remarkable that we’re still squabbling over fine details. The implementation costs of a system to ensure Asian carp stay out of the Great Lakes was recently estimated at a total of $18 billion, which, spread out over the long run is a pretty fair price for ensuring lake-based fisheries and recreation industries can continue to exist. As for any contamination from generating stations all over the Great Lakes–while it may be legal to pollute, the long-term cost of remediating polluted water still presents a greater cost than installing recommended pollution control measures. And while companies like NIPSCO may be able to subsidize the cost of pollution by shifting the financial burden of a need for more intense water purification to public entities, are we patriotic Midwestern Americans really willing to let industrial byproducts flow into our very own national park and create a potential public health hazard, as it did in 2012? Maybe the real question is, will we remember in time that everyone drinks from the lake, not only the fish?

Fish Herders

Fish Herders