Mysterious red tide killing abalone by the hundreds along Sonoma County coast

Abalone divers

If you've driven the Sonoma County coastline in Northern California you are familiar with maneuvering your RV along the twisting and turning Route 1, but well worth it for the dramatic sea coast scenery, whether it is foggy--common--or sunny.

And as Californians know, the months of September, October, and some of November are the clearest and sunniest of the year, when many RVers take to the coast for camping and the recreational pleasures of the north coast.

This is a good time to visit Fort Ross, Salt Point, and Bodega Bay State Parks. If you are an abalone diver, you know that this is the prime abalone diving area on the California coast. But the number of abalone have been shrinking over the past several years, much of it attributed to poaching since a single red abalone can sell for $100 on the black market.

Red abalone

In 1997 California Fish and Game banned the commercial harvesting of abalone, though red abalone over seven inches in size--which takes it ten years to reach--can be taken for personal use and only by snorkel diving, scuba gear is not allowed. It was hoped that this would help restore the abalone population. Then this disaster hit.

A mysterious "red tide" is killing off the abalone in large numbers, littering the shoreline and shallow waters with the dead shellfish. Though red tides are common along the coast, this one is particularly virulent, with the die-off spreading from Anchor Bay in southern Mendocino County to Bodega Bay, with Fort Ross the hardest hit area.

Authorities are guessing that a biotoxin discovered in the dead abalone and present in this particular plankton species is poisoning sea life. An emergency closure will be approved within the next few days, and divers are being advised to avoid the affected areas and refrain from eating abalone until further notice.

Red tide updates are posted by the California department of Public Health.