Everyone knows it takes two to tango. Unfortunately for Washington State’s endangered pinto abalone, it’s tough to tango when very few potential partners exist in the same area code let alone on the same dance floor. And since abalone are broadcast spawners that fling their eggs and sperm to the currents, their only real chance at reproducing is when they’re bunched up, like in a mosh pit. So, forget the tango. A more appropriate mating metaphor for this remarkable marine snail is that it takes at least six to slam dance.
Pintos are the Salish Sea’s only abalone species and, up until just 30 years ago, were considered plentiful in their rocky, kelpy habitat throughout the San Juan Islands and the Strait of Juan de Fuca. Historically, the Coast Salish gathered them at low tide for meat and the luminous, mother-of-pearl shells. With the surge in popularity of scuba in the 70s and 80s, “ab diving” became economically important to the Washington State tourist and recreation industry.
“If you dropped on the right spot, they were very easy to find,” says Tom Heinecke, a diver from Puyallup who grabbed abs in the San Juans for years before switching to hunting for photos with an underwater camera. “Nothing better than campfire cooking with fresh-caught seafood,” he says, remembering the summertime island trips. “With abs, we’d bread and fry them or just soak them in lime juice and eat them raw in salads. They were a big piece of solid meat, and a single five-incher was enough for one person.”
A dramatic decline
Washington never allowed a commercial abalone fishery, but sport divers took an estimated 40,000 pintos each year, with a daily bag limit of five per diver from 1980-1992. A bigger problem for abalone populations may have been the illegal take sold to local restaurants and exported to Asia. One Puget Sound poacher admitted to Washington Department of Fish & Wildlife (WDFW) officers that he’d heisted between 25,000 and 40,000 abalone. And he certainly wasn’t alone. The pinto’s necessity to gather in herds for spawning made poaching them as easy as shooting shellfish in a barrel.
“There are no other abalone species here, and no large marine snails of any kind to take their place. It would be a big loss to the ecosystem if we can’t restore their populations.”
In 1992, concerned with reports that divers were finding fewer abalone, WDFW lowered the bag limit to three, upped the size limit and established 10 index sites at known ab-rich areas in the San Juans to track density. After only two years of study, they realized the situation was dire and deployed the nuclear option, completely closing the abalone fishery. Unfortunately, they were shutting the barn door after the pintos had already bolted.
Research divers kept surveying the index sites and the numbers kept dropping. With no recreational fishery and not enough abalone left to attract large-scale poaching, the most likely explanation was that the density had fallen below the level needed to reproduce.
Scientists’ best estimate is that in order to have a self-sustaining population there needs to be at least one adult abalone every three square meters across suitable habitat. At that density, there’s a good chance that an animal responding to seasonal cues (likely some combination of water temperature, light duration and moon phase) will climb to a primo current-swept spawning site, encounter abs of the opposite sex and they can all go to gamete town. In the latest surveys, however, abalone density at the index sites was about 100 times lower than required. In real numbers, divers recently counted only a dozen abalone across the ten sites, with five found at one spot and eight sites with either one or zero animals.
“We’ve seen the pinto abalone population decline 97% since 1992,” says Hank Carson, research scientist and lead diver for the WDFW’s shellfish team. According to Carson, more evidence of the relationship between density and reproduction is the total lack of baby abs. “Not a single juvenile has been spotted by our divers in 12 years,” he says.
With little evidence of natural reproduction, pinto abalone are considered functionally extinct in Washington State.
“There are no other abalone species here, and no large marine snails of any kind to take their place,” says Carson. “It would be a big loss to the ecosystem if we can’t restore their populations.”
Any chance of a comeback, though, requires dramatic human intervention.
Pinto abalone are homebodies. Researchers believe they spend their entire lives within one small range near where they first settled as larvae. They don’t seem willing or able to travel long distances to find mates, so the first experiment at recovering the species was an abalone matchmaking service (dating apps like Tinder aren’t readily accessible to gastropod molluscs, in part due to poor internet service in the subtidal).
In 2007 and 2008, research divers collected adult pinto singles and relocated them to two sites with other abalone, hoping to spark breeding aggregations. Biologists monitored them closely for four years but saw no evidence of reproduction, and the abalone slowly disappeared.
“That’s when we decided that conservation aquaculture was the best answer,” say Josh Bouma, Abalone Program Director for Puget Sound Restoration Fund (PSRF).
PSRF, WDFW, NOAA, the University of Washington, the S’Klallam tribe and other partners began the delicate process of trying to resurrect a functionally extinct species by bringing abalone into a hatchery where they could induce spawning and larval settlement, rear the juveniles for a period of time and then outplant them into the wild.
Abalone are raised for food in many places around the world, but this couldn’t be a farming operation where animals are only bred with an eye toward getting them to the fish market as fast as possible.
“We’ve taken a very slow, cautious approach,” says Bouma. “It’s not the Johnny Appleseed method of just blanketing the waters. To ensure we’re not doing any harm, we need to produce and release only genetically diverse, healthy animals.”
What does a healthy pinto abalone look like? With hundreds of epipodial tentacles poking out from beneath its single shell, it looks like a Koosh ball wearing a hardhat. A pair of longer chemical-sensitive tentacles reach out from its head along with two simple eyes that sense light and dark. The ab’s puckered mouth harbors a radula—a raspy micro-toothed tongue-like structure that scrapes algae and biofilm off hard surfaces and tears into the blades of larger kelps. Pinto abalone shells have four to six flute-like holes used for respiration, gamete dispersal and waste elimination. They keep their one shell for life and, as they grow, older holes close and new ones form.
Haliotis kamtschatkana gets its common name “pinto” from the patches of color on its epipodium, the fleshy skirt surrounding its muscular foot. A snail given the same name as a pony seems like an ironic science joke, but this abalone actually has some giddyap.
“The foot looks like just one oval-shaped muscle,” says Bouma, “but it can walk that muscle back and forth in a bipedal movement and really gain some speed.”
“We call it galloping,” says Carson. “You see that behavior especially in the pinto abalone’s response to pycnopodia, the sunflower sea star.”
Sunflowers are major abalone predators, and the aquaculture program uses the pinto’s hard-wired fear of the sea star as a wrangling tool. The abalone’s foot can suck down so hard that even on the smooth plastic walls of the grow tanks they’re impossible to move without potentially injuring the animal. Hunkering down beneath their shell is the abalone’s primary defense against predators like fish and octopus, but sunflower sea stars can extrude their stomachs and engulf an abalone in digestive juices. So, when a pycnopodia approaches, the pinto picks up its skirts and gallops away. At the lab, when it comes time to move the juveniles for outplanting, the researchers simply toss a sunflower sea star into the tank. As the pintos rear and start galloping away, they’re gently swept up and placed in their PVC outplant modules.
The 3,500 young pintos destined to be rounded up this way in late spring 2020 are the ninth graduating class for the conservation aquaculture abalone program. They’ll be transported north by road from the Kenneth Chew Center for Shellfish Research and Restoration in Port Orchard and loaded on a WDFW boat. WDFW and PSRF divers will then hand carry the new recruits down to join the 22,000 juveniles already placed at 18 sites in the San Juan Islands and surrounding area.
According to Carson and Bouma, the slow, iterative approach of the program has been worth it.
“We’ve built a really strong foundation,” says Bouma. “The abalone we produced and outplanted so far are from 125 genetically distinct families, so that’s a lot of diversity we put out there.”
Endangered species status
In 2019, Washington State added the pinto abalone to its endangered species list. “That really helped,” says Carson. “It raises their profile, helps us educate the public, and puts real teeth in enforcement for any future poaching cases, which can now include big fines and prison time.”
It also loosened some purse strings for the pinto’s benefit, with the legislature approving an additional $900,000 that will go to greatly boost the restoration effort.
“We’re putting that into expanding the aquaculture program to include partners like the Port Townsend Marine Science Center and Seattle Aquarium, who will be rearing juveniles from larvae we produce at the hatchery,” says Bouma, estimating that the additional facilities will allow them to triple production.
The San Juan Islands-based SeaDoc Society is leading a mapping project that will determine the extent of suitable abalone habitat in order to help identify additional outplant sites for the new pinto herds. Bouma says that, overall, the aquaculture program may need to increase tenfold to have a real shot at restoring the species throughout its Washington State range.
“Other than hatchery production, the main limiting factor for pinto abalone restoration is survival of juveniles once we place them in the field,” says Carson, who’s appropriately prone to gastropod puns such as “helping them get their foot under them.”
Small abalone lead cryptic lifestyles until their shells are large enough to protect them from most predators, so it’s a challenge to find them before they emerge from the cracks and cavities as adults. However, from tagging studies where science divers find themselves upside down, heads stuffed in caves, probing the dark crevices with flashlights and tiny mirrors, the restoration team estimates that between 8.5 and 17% of hatchery juveniles survive to reach adult size, which takes approximately two years after release.
Still, research into further maximizing the number of little snails that live to become breeding adults is a high priority. The program is experimenting with releasing abalone at different sizes, even down to larvae, to determine the most efficient use of hatchery capabilities.
One vexing mystery they’ve run into is that there’s a big difference in survival rates on different outplant sites, even those that are just a few hundred meters apart and look, at least to human eyes, exactly the same.
“They all have plenty of food and suitable habitat,” says Carson, “but we see a huge disparity in survival between our best- and worst-performing sites.”
One strategy they’re using is to give up on failed sites and invest more in good ones, but in order to implement a wider restoration throughout the pinto’s historic range, the biologists still need to figure out the key to finding places where a greater number of juveniles will survive.
“We’ve eliminated a number of factors,” says Carson, “and our leading hypothesis now is that it’s predation.”
The same meaty molluscs once prized by scuba divers looking for a fresh serving of ceviche also attract a host of natural predators. Researchers wonder if certain local carnivores are adept at seeing the outplant pipes filled with juvenile abalone the same way we look at a can of Pringles. To find out, the team placed custom timelapse surveillance cameras alongside the outplants last season. While they’re still sifting through the 18,000 images, they’ve found at least one possible suspect, the greenling, a fish that divers know well as a curious species. The investigation continues, but they’re already considering defensive strategies.
“We didn’t see any greenling near the outplants at night,” says Carson, “so we may start releasing the pintos at sunset, which would give them all night to head for the hills.”
If the abalone team can solve the riddle of juvenile survival, the program has a good chance of creating a self-sustaining wild pinto abalone population that keeps increasing on its own, ultimately putting the hatchery out of business.
“That,” says Carson, “would be a great success.”