BALTIMORE _ Thousands of fish have died in recent days in the Gunpowder and Bird rivers in eastern Baltimore County, and officials believe a toxic algae bloom is to blame.
Maryland Department of the Environment investigators believe a toxic algae known as Karlodinium venifecum is to blame for killing about 10,000 yellow perch, largemouth bass, bluegill sunfish, pumpkinseed sunfish, carp, black crappie, gizzard shad, spottail shiner and channel catfish. Officials had previously estimated the toll at 6,000 fish, but revised that figure Wednesday afternoon.
Investigators are waiting for lab results to confirm that high levels of the algae are present. They do not believe pollution was a factor in the fish kill.
Fish kills are more common in the summer, when warmth and sunlight fuels algae blooms that, when they die and decompose, can also create "dead zones" with little or no oxygen in the water. But such kills can be caused by a variety of factors and occur any time of year, MDE spokesman Jay Apperson said.
