The rays of bats, striped bass, sturgeon, anchovies and oysters are presumed to be victims of the algal bloom that scientists are trying to discover. Scientists, local photographers, joggers and nature lovers have captured dramatic footage of the massive fish mortality.
Damon Tighe, a scuba diver who documents the lake’s wildlife, said Lake Merritt’s wildlife is incredibly diverse. The ecosystem of Lake Merritt in Oakland, California is unique in that it contains both fresh and salt water.
A variety of fish, crabs and shellfish live in the lake, as well as a large number of gray egrets, great egrets, geese and ducks. In recent years, salmon, sturgeon, jellyfish, and leopard sharks have all been swimming in the lake.
The killing of the fish is believed to be caused by the growth of a microscopic type of algae called Heterosigma akashiwo, which was first discovered in late July in several parts of San Francisco Bay and in estuaries. According to assumptions, this type of algae absorbs all dissolved oxygen, so the fish suffocate, says John Rosenfeld, a scientist with the San Francisco Bay Wildlife Conservation Organization, who researches this phenomenon.
Heterosigma akashiwo also produces a toxin, which can also cause fish to die.
The result is red-brown water in which thousands of puffer fish carcasses float. According to the San Francisco Bay Area Regional Water Quality Monitoring Board, on August 10, the algae density reached over forty years ago.
(MTI)
