Baltimore-Area Fish Kill Investigation Ongoing

A menhaden fish kill. Photo: Chesapeake Bay Program

The Maryland Department of the Environment (MDE) is investigating a menhaden fish kill that appeared in the Patapsco and Back Rivers over the weekend.

Explanations for a fish kill, a localized die-off of a population of fish, include lack of oxygen, disease, and pollution.

The deceased fish were found in the Patapsco River around Canton and in Back River. The MDE estimates the fish kill to be 30,000 Atlantic menhaden.

The MDE says that there’s currently no indication that the fish kill, believed to be a single species event, was caused by pollution. The water in the area has been tested and shows adequate levels of oxygen and no issues.

MDE spokesperson Jay Apperson says the menhaden may have become distressed and died elsewhere. “It is possible that dead menhaden at the mouth of the Patapsco River and mouth of Back River were carried by wind into those waterways. We collected fish that appeared to be dying to examine their tissue. It is possible that fish were distressed and as a result diseased, however no cause has been determined at this time and the investigation is continuing.”

-Laura Boycourt