By Jenny Krusoe
Two species of abalone are trying to make a comeback from near extinction, but their future as an important part of Southern California’s seascape remains uncertain.
To gauge how well the black abalone and white abalone have recovered, the federal government is conducting a five-year review of the endangered designations on both species. As well, scientists are seeking public help to determine where the creatures now live, as they continue to try to rescue the species.
Abalone, actually largely sedentary sea snails with flattened spiral shells, come in several species and colors. Their immobility and method of reproduction make them particularly vulnerable to extinction when over fishing depletes their populations. Add in issues caused by rising sea temperatures, pollution and declining kelp forests and the mollusks have been in dire condition for more than 20 years.
The implications for coastal waters off California go far beyond the abalone species too. Marine researchers say the mollusks are critical to near-shore ocean ecosystems because they keep algae in check and are a major food source for sea stars and sea lions.
“They play an important role in the kelp forest ecosystem as a grazer and an herbivore,” said Chris Yates, who administers the fisheries service’s West Coast protected resource division. “Without abalone, the system is out of balance. Humankind is responsible for the state of these critters, so we have an obligation to keep them from going extinct since our over fishing caused their current problems.”
Accordingly, in 2001, the federal government took the strongest action available, designating both white and black abalone as endangered species.
Fifteen years later, the National Marine Fisheries Service is seeking public comment by Feb. 21 on its five-year status review. To track the extent of the two species, which are native only along the Baja and Southern California coastline, scientists asking for help.
The few wild abalone colonies, particularly off Catalina and the other Channel Islands, are closely monitored. But scientists want to know about other populations beyond those known areas. They’re asking anyone sighting wild abalone along the shoreline or while diving to notify researchers of the creatures’ location, apparent health and numbers, among other details.
“Any information about sightings of the animals or threats to the animals would be really helpful,” said Yates.
Fishers prized white abalone as a delicacy when they were still legal to harvest. The whites are generally larger than their pink, green, black or pinto cousins. Black abalone also were heavily harvested, but that species also has been hard hit by a bacterial wasting disease. Six other abalone species worldwide also are struggling.
The few remaining wild abalone colonies on the West Coast are far between, a situation further worsened because there aren’t enough of them in proximity to each other to consistently reproduce. Adult abalone move very little, and spawn when males and females shoot dense clouds of eggs and sperm near one another. Without close-knit populations of both genders, an abalone colony can die out, even though the animals can live more than 30 years.
To overcome issues with population density, scientists at the UC Davis Bodega Marine Laboratory have spent years researching how best to grow abalone in tanks. The scientists hope to seed tens of thousands of lab-grown white abalone back into the wild in the next few years.
An AltaSea partner also is involved in recovery efforts. The Cabrillo Marine Aquarium in San Pedro is spawning abalone, then sending the juveniles to UC Davis where they can grow to adulthood.
At the same time, scientists are working to genetically diversify their breeding populations, and developing techniques to help transplanted populations to better thrive in the wild. They are studying wild populations and also using red abalone planted off the Palos Verdes Peninsula to learn what works and what doesn’t.
In time, these sustained efforts may bring back two of Southern California’s most beloved and important species, part of AltaSea’s mission to rebuild a sustainable and thriving ocean that can help us all thrive as well.
Jenny Cornuelle Krusoe is the executive director of AltaSea at the Port of Los Angeles. Krusoe, a California native based in San Pedro, has a national reputation as a nonprofit executive and senior advisor on organizational and program design and fund development. Krusoe has been a member of the leadership team since the innovative ocean sustainability and marine science campus was first conceived.