Friends of Fox: Despite IDPH 'Do Not Eat' Suggestion, Fox Fish Are Getting Cleaner By The Decade

Friends of Fox: Despite IDPH ‘Do Not Eat’ Suggestion, Fox Fish Are Getting Cleaner By The Decade

  • EDITOR’S NOTE: This essay was written by Art Malm, a board member of Friends of the Fox River and the Fox River Study Group. Malm is a retired professional engineer with five decades’ practice in the field of civil engineering.

First, an admission. Our fellow citizens working at the Illinois Department of Public Health deserve all the credit in the world for what is an “all hands-on deck” emergency with COVID-19. It is understandable why IDPH has yet to be able to respond to my questions about their latest fish tissue studies. They are heroes and we hope they will soon be able to get back to the “normal” work piling up on their desks.

The purpose of this essay is to clarify some of the data and to let people know the big-picture truth: Our Fox’s fish have been getting cleaner by the decade.

The Kane County Connects Aug. 19, 2021, edition headlined a mercury consumption “do not eat” guideline for largemouth bass on our Fox. That was a bit of a surprise for those of us following the IDPH/IEPA Fish Contaminant Monitoring Program.

We were surprised only one specie, and only one section of our river, was announced with methyl mercury contamination. All of Illinois’ waters have mercury contamination advisories for its larger predator fish like the bass, the musky and the walleye.

The IEPA has been monitoring mercury in our Fox’s fish for decades. The number doesn’t go down much. That’s because the greatest source of mercury in our Fox is likely the burning of coal for electricity, and air pollution has few borders.

The mercury in the fish of our Fox is at a level below many of the fish found in our supermarkets and restaurants. Any fish other than salmon (and tilapia?) is a fish pregnant women and young children should eat sparingly or avoid.

Chart A Fish Tissue Mercury Content 1988 to 2017

The good news we hope to hear someday soon is the “all clear” for PCBs in our Fox’s fish. When last checked, our Fox still has a PCB-based “do not eat” advisory for at least two of its species.

Our Fox’s fish PCBs have dropped dramatically over the past 40 years. I suspect the Fox River Valley will be among the next recognized for success controlling this type of water pollution.

From the data, our Fox’s fish now appear almost free from PCB contamination.

Chart B Average PCB Levels 1974 to 2017

Next Steps

What is the NEXT step in our Fox’s restorations?

Experts agree the next great improvement in our Fox’s water quality (and fishing!) will come with the removal of its obsolete dams from Carpentersville downstream to Yorkville. The Kane County Forest Preserve District is leading the way with removal of the Carpenter dam scheduled for 2022, allowing a portage free river trail from Algonquin to Elgin.

Drone shot, Carpenters Dam. DJI_758. Fox River Study Group researchers placing water quality monitoring sondes in 2020.

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