Sunday, May 15, 2022

Fish Kill in Tidal Four Mile Run

Anyone visiting lower Four Mile Run in the last several days should have noticed many dead fish, large and small, along the streambank and floating out in the water, the result of a pollution incident that occurred some time Thursday, May 12. Here is what we know at this time:

Early Friday morning one of our volunteers reported seeing dead fish, and we immediately notified Arlington County, Alexandria City, and state and regional authorities that there had been an incident. Although at the time it seemed possible it was related to stormwater runoff overnight, an eyewitness reported seeing fish swimming sideways on the surface on Thursday. Although turtles, waterfowl, and snakes appear not to have been affected, it seems that all fish that were in the tidal portion of the Run were harmed, and thousands died: minnows, bluegill, catfish, gizzard shad, carp (many large, easily 15 pounds in size). At the present time the incident is still being investigated, and we will update this post as more information comes available.

As of Sunday, live fish of several species were again observed in the Run, so whatever pollutant caused the sudden die-off has either dissipated or washed out with the tide. If you noticed anything unusual, or if you can help pinpoint the timing of the incident, please contact us!