Tiny as a fingernail, these babies don’t look like much. But there is a lot of hope riding on their progress.
These pinto abalone are being raised by the tens of thousands in dozens of 30-gallon tanks at the Seattle Aquarium. It’s a conservation venture to restore a native species at grave risk of extinction in the Salish Sea.
Overfished in just 40 years, pinto abalone, a marine mollusk, are a state endangered species. The effort underway at the aquarium is intended to eventually change that.
“We are committed to this until they don’t need us anymore,” said Erin Meyer, director of Conservation Programs & Partnerships at the aquarium.
Long a favorite visitor attraction and an important rescue and rehabilitation option for wildlife in need, the aquarium is growing its work to take on species recovery, through breeding, rearing and releasing endangered species to re-establish wild populations.
Pinto abalone have always been pursued by people, both for their meat and the beautiful inside of their shell. The sport fishery for pinto abalone was closed in Washington by 1994, but poaching continued. By the time the fishery was closed, pinto numbers already had so declined that the population was not rebounding on its own.
From 1992 to 2017, the WDFW documented a 97% decline in abalone within 10 fixed survey stations in the San Juan Island. The state listed pinto abalone as endangered in 2019.
The pinto abalone rearing project and introduction project is being undertaken with the nonprofit Puget Sound Restoration Fund, the Washington Department of Fish and Wildlife and other partners that have been captive rearing pinto abalone since 2003.
The facility at the aquarium will upscale that effort and enlist the assets of its scientists, animal care staff and divers on the pinto team.
Opened earlier this year, the rearing facility is outside the aquarium behind locked fencing, facing Alaskan Way. The facility consists of stacked rows of what look like blue plastic baby pools, each with 500 pinto abalone hatchlings, going about their slow, quiet day.
They don’t move much: Close inspection reveals a halo of delicate tentacles at the edge of their shell. The shell is brown and rough, looking rather like a rock. Watch closely and you’ll see a bit — a very tiny bit — of movement as the mollusk’s muscular foot peeps out from under its oval shell. Dull on the outside, its nacre gleams pearlescent within. The outside color of the shell will change depending on what the abalone are eating. Algae also grows on the outside of their shell, tinting them pink, green and brown; each shell is unique.
An aerator fizzes fresh oxygen into each pool, which is filled with fresh cold filtered water from Elliott Bay. Each of the tanks has a fresh chiffonade of the pintos’ favorite red and emerald green algae on which the abalone may graze.
Pinto abalone in the wild don’t have it nearly so good, especially the babies. Nearly everything eats them. Fish, birds, anemones, sea otters, octopus, most anything with a mouth. But it has been humans with their knife and fork, not other wildlife, that have nearly done them in.
So depleted are pinto populations today that it will take restocking their native habitat to rebuild their numbers, Meyer said.
Pinto abalone belong here; they are part of the suite of life in the subtidal zone. The only abalone species found in Washington waters, the swaying green forests of kelp beds aren’t complete without their quiet mollusk ways. By grazing diatoms and other algae off rocks with the toothed tongue-like structure in their mouth, called a radula, pinto abalone literally clear the way for other animals and plants to attach to the rocks, helping to maintain a diverse and healthy rocky reef and kelp forest.
Abalone and other mollusks also have been here forever, since the beginning of animals on our planet. They first appeared in the fossil record in the late Cambrian, 542 million years ago. So if getting here first counts, they surely have dibs.
Their requirements in the wild are modest. Pinto abalone can move along quickly (for a mollusk) at several feet per minute if they are disturbed, sense a predator or are on the giddyup to a mass-spawning event. Otherwise, though, they pretty much just mollusk on, sticking to their home rock. They occupy small home ranges of just a few square feet for life, seldom leaving as long as there is food around.
To our knowledge, their senses are limited. They can perceive and respond to light, dark and vibration, and their central nervous system can process chemo-sensory information picked up by their tentacles, such as the smell of kelp and other food. They breathe through gills.
In addition to algae to eat, they need one another. Pinto abalone are broadcast spawners, meaning they release billions of sperm and eggs into the water, once a year, typically on a fine full moon night in spring or summer. But fertilization won’t be successful unless there are enough animals of both sexes near one another.
Pinto abalone are not picky about where they live. They will utilize a wide sweep of habitat in the Northeastern Pacific, in the rocky, current-swept reefs and kelp forests from Alaska to California.
The aquarium started its first batch of juveniles last April. The facility is in temporary quarters now and will move to permanent home in the aquarium’s animal care center next year, when the number of tanks will be increased from 38 to 40.
The first pinto yearlings, by then an inch long, should be ready for releases to the waters of the San Juan Islands and Strait of Juan de Fuca by spring of next year. Annual releases are expected thereafter.
Hard to imagine in their tiny shells today, pintos can grow to the size of an adult’s hand. Their growth is slow, at about 1 millimeter per month on average for the first two years. It takes six to eight years for pinto abalone to reach maturity and reproduce, at a size of about two to three inches.
The effort to re-pinto Washington waters is the first of more species recovery work to come for the aquarium, Meyer said.
Next up: zebra sharks, from the Indo West Pacific, working with some 60 partners and eight countries.