The toxin is naturally-occurring but this year's event is anything but normal. Effects on mammals and birds seem to be worse than anyone has ever seen. Scientists suspect the upsurge has been caused by such things as overfishing, destruction of wetlands and pollution, all of which have harmed fisheries and allowed algae to flourish, according to the Los Angeles Times.
The toxin, domoic acid, is produced by microscopic algae, gets concentrated in fish and shellfish, and can poison birds and mammals who eat the fish and shellfish.
Algae blooms such as "red tides" have long been known, but recently seem to be causing more trouble. A particularly scary version, pfiesteria, caused a near-panic in the late 1990s on the US East Coast.
Another in a long list of reasons to work for healthy oceans...probably fewer toxic algae bloomsTweet