Posted on behalf of Heidi Ledford

A neurotoxin made by marine diatoms may be lingering in ocean sediments well after the algal bloom has faded, a new study has found. The results suggest that the toxin, called domoic acid, may impact deep sea ecosystems in unexpected ways.

Domoic acid, produced by an unassuming pinnate diatom called Pseudo-nitzschia, can cause short-term memory loss and seizures in animals and the seafood-loving humans who eat them. (The sea lion shown at right is thankfully on the mend after being treated at the Marine Mammal Care Center at Fort McArthur in San Pedro, CA.) But domoic acid is perhaps best known for triggering a rash of bizarre bird behavior in Capitola, California in the early 1960’s – an event believed to be the inspiration for Alfred Hitchcock’s movie The Birds.

A study published yesterday by Nature Geoscience (subscription required) shows that toxin-laden diatom carcasses sink rapidly in the ocean and accumulate in sediment up to 800 meters below the surface. The results suggest that bottom feeders could also get a nasty dose of the poison, but monitoring programmes only test for domoic acid in surface water algal blooms, notes Reuters.

Image: Astrid Schnetzer