Black Abalone: living on the edge and in need of critical habitat

When I first began scuba diving over 25 years ago, my enthusiasm for the sport took me in all directions - photography, teaching, wreck diving, hunting, you name it. As I learned more about the health of the oceans, I soon abandoned hunting and have focused on the visuals, following the adage of "shoot only pictures, leave only bubbles, take only memories."

But back in my hunting days, abalone, a large shellfish found along the California coast and adjacent Channel Islands, was highly sought after. In fact, back then a diver could reach the State-allowed limit for a multi-day dive trip (a total of 8) in just one dive. The dive boat would anchor at one of the prime spots where you could find large abalone strewn across the bottom like hubcaps!

Then times changed. Already impacted by commercial harvesting, recreational harvesting was limited even further. The dive boats would often avoid the good spots, which were becoming harder to find anyway. And eventually a full moratorium was put in place.

There are several species of abalone - black, red, pink, white, green (their names based on either a basic shell color or the color of the short tentacles and fleshy mantle that extend from underneath) and each species today faces various degrees of decline, although all have suffered badly over the years.

The black abalone has declined as much as 99% since the early 1970s. Historically, abalone was harvested by the Chumash Indians that inhabited the California coast and Channel Islands. With the onslaught of the otter fur trade (otters also fed on abalone), the population of black abalone swelled. But, in response, so did the commercial harvesting industry. With abalone populations in decline, their overall health and robustness impacted, they have experienced a near fatal blow with the outbreak in the '80s of a bacterial disease called Withering Syndrome which attacks the digestive enzymes and the abalone begins to basically wither away.

The black abalone has been placed on the IUCN Red List as critically endangered. In 1999, the U.S. National Marine Fisheries Service (NMFS) began considering the black abalone for endangered status but, with considerable prodding from outside conservation groups, it took nearly 10 years for the black abalone to be officially designated as an endangered species.

While such a designation legally requires that measures be taken to protect the species, to date no critical habitat has been set aside for the black abalone. And this has spurred the Center for Biological Diversity to file an intent to sue.

“Critical habitat protections have a proven track record helping endangered species to survive,” said Catherine Kilduff, a staff attorney at the Center for Biological Diversity. “Species with critical habitat are twice as likely to be recovering as species that don’t have it. Black abalone is on the cusp of extinction, and any further delay of federal habitat protection may well seal the species’ fate.”

The black abalone is in a precarious position: it's numbers reduced by over-harvesting; hammered by a pernicious Withering Syndrome; with increasing ocean temperatures that will aid the spread of the disease and the potential of ocean acidification to weaken the health of early-stage juveniles. The NMFS needs to act quickly and the world must recognize that another "canary in the coal mine" species is living on the edge due to the effects of climate change and CO2 emissions.

Read press release from the Center of Biological Diversity.