Can a Salish Sea snail come back from the brink of extinction? Scientists, Hope So Tribe

0

Ysabelle Kempe / The Bellingham Herald

A sea snail on the brink of extinction receives help from researchers at Whatcom and the Lummi Nation as Washington expands pinto abalone restoration efforts.

Pinto abalone is the only species of abalone native to Washington waters, contributing to healthy kelp forests that support a food web that includes killer whales and salmon. They are culturally significant and a traditional food for the Coast Salish tribes.

“They’re like the Roombas that keep the seabed clean and allow other invertebrates and kelp to settle in those spaces,” said Katie Sowul, a biologist working on pinto abalone restoration at the Department of Fisheries and Wildlife. Washington wildlife.

But these ocean creatures are coveted by humans for their iridescent shells and world-famous meat, which can fetch $125 a pound. Pinto abalone have been overharvested and poached to the point that a natural rebound in the Salish Sea is unlikely. Between 1992 and 2017, the number of pinto abalone found in surveys declined by 97%. Climate change is putting increased pressure on the species: as humans continue to burn fossil fuels, the ocean absorbs more carbon dioxide and becomes more acidic, which can damage abalone shells.

“Abalone populations have plummeted in most parts of the world,” Deb Donovan, a professor in Western Washington University’s biology department, said at a university-hosted event on Thursday, February 10.

The pinto abalone made headlines in 2019, when Washington designated the species as endangered. The move opened up funding for restoration work and raised public awareness of pinto abalone, said Henry Carson, fish and wildlife research scientist with the Department of Fish and Wildlife.

But it could take a decade before biologists see real results, Sowul said.

Here’s how the restoration team works: divers collect wild pinto abalone and bring them to the Puget Sound Restoration Fund hatchery in Manchester, where they are reared. Snails are broadcast reproducers, which means that they do not physically touch each other to reproduce. They release sperm and eggs into the water, which meet and form larvae smaller than a grain of sand. If abalone populations are not dense enough in the wild, the chances of successful breeding diminish.

Biologists raise the young abalones for 12 to 18 months, eventually releasing the juveniles into an ideal habitat for pinto abalones: smooth rocks covered in seaweed and kelp, with plenty of crevices to hide from predators. Then the waiting game begins, until researchers return the following year to see how many juvenile abalones survived.

Last year, the team released about 10,000 juvenile pinto abalone at 10 sites near the San Juan Islands. (These sites are top-secret due to poaching concerns.) Current monitoring shows serious gains: one site had an 8% survival rate, which doesn’t include abalone hiding where divers don’t. couldn’t see them.

“It seems weak, but this species makes a lot of babies. Many don’t,” Sowul said. “That’s how grazers work at the bottom of the food chain.”

Abalone Pinto near Whatcom

Now that the restoration team knows they can successfully replant juvenile abalone, they look forward to ramping up production and release work, said WDFW scientist Carson.

This momentum will likely carry restoration efforts to waters near Whatcom County. The Lummi Nation is currently looking for locations with inviting pinto abalone habitat. Hatchery-raised abalone could be planted at those sites as early as this year, Carson said.

The Lummi Nation could possibly help raise pinto abalone in its shellfish hatchery, said Karl Mueller, the tribe’s shellfish biologist.

“Right now, we’re literally putting our toe in the water with site visits,” Mueller said.

Western Washington University researchers are also playing an important role in pinto abalone restoration. A graduate student’s work helped determine the type of phytoplankton the hatchery feeds very young abalone to better support survival and growth. Another student researched how to cryopreserve or freeze abalone sperm so it can be used later. (This gives researchers the ability to better control and maximize the genetic diversity of their hatchery-reared abalone population, WWU Professor Donovan said in his speech Thursday.)

Another student discovered that abalone larvae can be transplanted successfully into the wild. This discovery has significant financial implications because it is expensive to care for juvenile snails at the hatchery, Donovan said.

“If we manage to plant larvae that are only a few days old, it could save a lot of time and money,” she said. “It could also help with survival rates, as animals bred in captivity don’t have the same response to predators and food.”

The Washington Department of Fish and Wildlife will soon release its final pinto abalone recovery plan, which is a document that guides the restoration process.

Share.

Comments are closed.