Fungicide Fish Kill

This headline appeared in the Pittsburgh Post-Gazette on July 17, 2021: 
Fish and Boat officials investigate ‘significant fish kill’ in Chartiers Creek

“Waterways conservation officers were dispatched and were on scene that evening and Friday. They found dead fish on banks and floating in the creek. The officers pinpointed the fish kill to a roughly 7-mile long area from around the Valley Brook Country Club in Peters to 7 miles downstream.” Source

The kill zone was later extended to 10 miles. Chartiers Creek surrounds the golf course mentioned in the story on three sides, could there be a link? 

On August 4, 2021, a follow-up story was posted in the Pittsburgh Post-Gazette: 

DEP determines cause of Chartiers Creek fish kill to be fungicide

“At this time, the DEP won’t comment on potential source or sources of the contamination, or if any enforcement actions will be taken, because it is an open compliance matter, Ms. Fraley said. The fish kill was estimated to have killed thousands of fish, according to the DEP. It was reported to have occurred on July 15, but the DEP was not made aware of it until July 16.” Source

From the Observer-Reporter on August 4, 2021:
“The DEP declined to comment on the potential source or sources of the fungicide. The fish kill was reported July 15, but the DEP believes the fungicide entered the water the day before. Fraley said a delay between the time the incident reportedly occurred and the time it was reported “has been a significant impediment to DEP’s investigation.” Source

If you Google “golf course fungicides” one of the first hits includes this information on the fungicide’s MSDS sheet: 
“ECOLOGICAL INFORMATION – Summary of Effects: This product is a fungicide that is mixed with water and applied as a spray for control of plant diseases . The active ingredient, chlorothalonil, is practically nontoxic to plants, algae, birds and insects but is slightly toxic to mammals, and highly toxic to fish and aquatic invertebrates. Environmental Fate: Chlorothalonil has a low bioaccumulation potential, low mobility in soil and is not persistent in soil or water. The dissipation half-life in soil is 10-60 days and in water it is <8 days. The main route of degradation is by microbial degradation and formation of bound residues.”

Another turf fungicide’s MSDS includes this: 
“ECOLOGICAL INFORMATION: Azoxystrobin – Very toxic to aquatic life. Low bioaccumulation potential. Not persistent in soil. Stable in water. Moderate mobility in soil. Sinks in water (after 24 h).”

Whatever the source of the fish kill fungicide is found to be, we are all once again reminded that run-off from our lawns, sidewalks and driveways can reach waterways quickly during a rainfall event, which is why many municipalities have added these sorts of reminders to storm drains along roadways, “DRAINS TO DRINKING WATER. PLEASE DON’T DUMP.

So if you are using any sort of fertilizer or pesticide on your lawn, be sure to sweep granules off paved surfaces onto the lawn. Always read and follow label instructions on all chemicals you use, and be sure to dispose of pesticides safely through community “Chem Sweep” events.


MORE: During that mid-July time frame, conditions would have been right for Pythium Blight
“Pythium blight may develop when night temperatures exceed 65°F in cool-season turf and leaves are continually wet for 12 to 14 hours for several consecutive nights. For this reason, severe Pythium blight epidemics in cool-season turf are commonly observed the morning after a late afternoon or early evening thunderstorm in the summer. Daytime temperatures above 85°F also encourage Pythium blight development in cool-season turf, possibly due to increased stress.”
“Due to the potential for rapid development of this disease, high value areas and susceptible grasses should be protected with a preventive fungicide program. Applications should be initiated when night temperatures consistently exceed 65°F for cool-season turf and repeated on 14 to 21-day intervals as directed on the fungicide label when conditions are favorable for Pythium blight development.”

2 Comments on “Fungicide Fish Kill

  1. The DEP informed me the active ingredient was Chlorothaloni?l

Leave a Reply

%d bloggers like this: