A widespread fish kill is underway across Mobile Bay. It appears to be affecting primarily filter-feeding fish such as menhaden, sardines, alewives and shad.
Dead fish are present in the shallows and on beaches on both sides of the bay, from Point Clear to Daphne on the eastern shore and from Arlington Point south to Fowl River on the western shore. Dead and dying fish also dot the surface of the bay, from one side to the other.
The kill does not appear to be related to a red tide bloom occurring in the Gulf of Mexico and around Dauphin Island. Instead, the bloom in the upper bay appears to be another species of algae with a similar neurotoxic effect on fish.
Fish affected by the algae swim in a markedly erratic fashion, zipping straight ahead for a time, then falling into lazy circles, often swimming on their side or even upside down.
...
Mobile Bay Fish Kill - Video | AL.com
"While this is concerning and we will continue to look at the cause of the kills, we are really only seeing the very small planktivores being affected at the moment," Robertson said. "And fish such as menhaden are particularly sensitive to changes in their environment."
Dead or dying fish were visible at all times during the AL.com trips across the bay. Pelicans were seen swimming around on the surface of the bay scooping the dead fish out of the water. Likewise, pods of dolphins were seen gorging on the stricken fish.
Algal blooms in the bay typically peter out after a few days. This bloom has been particularly long-lived, and is already into its second week.
While only filter feeding fish have been affected, fishermen around the bay have reported that both speckled trout and redfish appear to have vacated the areas where the sick fish are visible.
