Large fish kills washing up in Orange Beach, Alabama, USA

Due to extreme heat and a lack of wind, fish kills are growing in number in the back bay areas of Orange Beach, Alabama. This kill was spotted on Cotton Bayou on the morning of Monday, August 3, 2015. (Courtesy/City of Orange Beach)

Widespread fish kills are occurring in the back-bay areas of Orange Beach and the summer heat wave appears to be the main culprit, according to Orange Beach Coastal Resources Manager Phillip West.

 

The unrelenting heat coupled with light northerly winds have prevented any kind of mixing of the waters to help oxygenate them, West said. Adding to the situation are schools of alewife, or possibly menhaden, which are extremely sensitive species. 

 

“So these species are up in huge numbers in waters that are already pretty stressed for dissolved oxygen and it’s just a recipe for a fish kill,” West said.

 

The first large fish kill was reported in Cotton Bayou on Friday and sightings continued throughout the weekend from Robinson Island, north of Perdido Pass, to Bayou Saint John, between Ono Island and Bear Point.

 

Most of the dead fish, typically between 4 and 7 inches long, have been found in Cotton Bayou, according to West.

 

An explanation for the events, West said, can be found in the pages of “Guide to Fishes of the Gulf of Mexico,” a book by Bob Shipp, the former head of marine sciences at the University of South Alabama.

 

“It says during summer months menhaden often congregate in shallow, poorly flushed estuaries. They’re intolerant of low dissolved oxygen levels such as those found in hot, still waters. Thus, fish kills may occur in a chain reaction,” West said.

 

The dead and decaying fish remove even more oxygen, resulting in more kills. “So it’s kind of a textbook phenomena just based on our conditions right now,” West said.

 

While out on Cotton Bayou Monday morning, West said one resident said he hadn’t seen fish kills that big since a record-breaking heat wave 25 years ago.

 

If the weather conditions persist, more fish kills are likely.

 

To address the problem, the city has placed a large garbage bin at the Boggy Point boat launch for residents to get rid of fish. Also, on Tuesday, the council is expected to discuss the possibility of mobilizing its debris contractor to assist with the cleanup. 

 

“I think this is probably the largest fish kill in the estuaries I’ve ever seen,” West said. “I’ve seen kills related to red tides and other things, like brown tides, that were pretty extensive. But of this type, this is definitely the largest that I’ve seen. I also can’t remember having gone through a July that was so unbearably hot for so long. Something was bound to happen.”

Courtesy of al.com

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