“Natural causes appear to be the reason,” the Maryland Department of the Environment said in a news release. “Cold water stress exacerbated by a large population of the affected species (juvenile spot fish) appears to be the cause of the kill.”
Two million fish found dead in Maryland
In Maryland, preliminary tests showed water quality to be acceptable, officials said.
“The affected fish are almost exclusively juvenile spot fish, 3 to 6 inches in length,” the Maryland department said. A recent survey “showed a very strong population of spot in the bay this year. An increased juvenile population and limited deep water habitat would likely compound the effects of cold water stress.”