A harmful algal bloom – first identified in 2004 – last month killed about 10,000 fish in Lake Merritt/ leaving researchers concerned about the migratory patterns of local seabirds.
The algae bloom, Heterosigma akashiwo is “a selective killer” that creates a toxin in fin fish, but isn’t known to climb the food chain. If the “red tide” further decimates fish populations, conservationists say local migratory birds in desperate need of food might be in trouble.
California’s Ocean Protection Council called the harmful algal bloom the “largest in recorded history,” with fish washing up dead across the bay. But the highest number of dead fish were at Lake Merritt. Biodiversity explorer Damon Tighe suspected that low oxygen dead zones within Lake Merritt, as well as the increasing nutrient levels from water treatment plants, contributed to the bloom's size and severity.
Researchers have stated that wildlife conditions are slowly improving for Lake Merritt. But they warn we could still see another devastating bloom like this next year, if nutrient levels from water treatment plants remain unchecked.