Creature Feature: Pinto Abalone
Pinto abalones raised in a lab at Puget Sound Restoration Fund to study their habitat needs. Photo by Josh Bouma.
The pinto abalone (Haliotis kamtschatkana) is a beautiful sea snail that lives among the rocky crevices of bull kelp beds in the North Pacific Ocean.
Shells have been prized for their beauty and used for Coast Salish and Northwest Coast carving inlays, jewelry, ash trays, and household decorations. Image by James St. John, Flickr CC 2.0
Abalone belong to the phylum Mollusca and class Gastropoda, which is made up of snails and slugs. There are 60 species of abalone worldwide - varying in size, shape, and color - but the pinto abalone is the only one that can be found in the Salish Sea and Salish Sea heroes are working hard to help their populations grow.
Because the pinto abalone’s range stretches so far north, from California to Alaska and Japan to Siberia, it is sometimes called the northern abalone. The pinto abalone has a coiled, flat, calcium carbonate shell with 3-6 holes for waste (pinto poop portals-bombs away!). .
The outside of this 8-15 cm (3-6 in) shell is reddish pink with white and blue markings, while the inside is a gleaming, iridescent silver, and often used for jewelry and decor.
A wild pinto abalone hangs from its strong, yellow foot from a rock exposed at low tide. Photo by Dave Cowles, Rosario Marine Station, Walla Walla University
Pretty in Pink…Camo!
Abalone have a muscular organ called the foot that they use to cling tightly to rocks. The pinto abalone lives in rock crevices in the low intertidal to subtidal zone, up to 20 m (65 ft) deep. Here, they have a special relationship with coralline algae. This pink, encrusting algae will grow on an abalone’s shell, creating camouflage and allowing the abalone to hide from predators.
A scanning electron micrograph (SEM) of a juvenile pinto abalone radula, the toothed “tongue” they use to scrape algae from rocks for lunch. SEM by Lillian Kuehl, Western Washington University
Subtidal vacuum cleaner
This alga also happens to be the pinto abalone’s favorite food-- they scrape it from rocks using their file-like tongue, or radula. Rad! Planktonic (free-swimming) larval abalone even rely on chemical cues from coralline algae to find a place to settle down. As young abalone grow, they first eat diatom (a type of phytoplankton) slime, then graduate to eating coralline algae, bull kelp (Nereocystis luetkeana), and seersucker kelp (Costaria costata). Pinto abalone also help the kelp, though-- their grazing keeps rock surfaces clear so kelp has places to which it can attach.
Many Salish Sea creatures including giant pacific octopus, lingcod, rockfish, sea and river otters, and sea stars hunt pinto abalone. Though the pinto abalone might appear helpless to predators, it actually has impressive defense mechanisms! When a predatory sea star like a sunflower star (Pycnopodia helianthoides) or six-rayed star (Leptasterias hexactis) touches a pinto abalone, the abalone can quickly twist its shell side-to-side and crawl away at a speed of 15 shell-lengths per minute, all while waving its small-but-mighty tentacles. Sometimes
These gastropods aren’t sluggish around predators...
A symbiotic scaleworm that will pinch a pinto’s predator when it tries to attack! This one is bunking with a keyhole limpet, which also benefits from the bite. Photo by Dave Cowles, Rosario Marine Station, Walla Walla University
the pinto will be helped by a friend, the scaleworm Arctonoe vittata. This scaleworm has a mutualistic relationship with pinto abalone (and with many other animals as well) because both organisms benefit from interacting with one another. The scaleworm takes refuge on the abalone’s shell and in return protects the abalone by biting its attackers!
Abalone… sandwich?
Pronounced “a-baloney,” it’s not surprising that abalone is also a popular meal for humans (and way better than baloney). Unfortunately, commercial and recreational fishing and especially poaching of pinto abalone caused a lot of trouble for the species. Pinto abalone are vulnerable to overharvesting because they 1) grow slowly, 2) have a patchy distribution (they are very spread-out in the environment), and 3) have low recruitment (not many larvae survive to adulthood). They reproduce by broadcast spawning, where males release sperm and females release eggs into the water in hopes that they will meet. With fishers catching up to 38,000 abalone from the Salish Sea each year before restrictions were put in place in the 1990s, it became very difficult for remaining pinto abalone to find one another for spawning. This meant the population couldn’t grow.
Salish Sea Heroes to the rescue!
In the early 1990s, British Columbia and Washington closed their abalone fisheries. By this point, though, the pinto abalone was already near extinction and continuing to decline. The Washington Department of Fish & Wildlife recorded a ~98% decline from 1992 to 2017, leading them to list pinto abalone as a State endangered species.
Salish Sea heroes are committed to working together through partnerships to restore pinto abalone in the Salish Sea. The Washington Department of Fish and Wildlife, the University of Washington, Puget Sound Restoration Fund, and NOAA started the first conservation aquaculture program to grow healthy juvenile pinto abalone. They raise pinto abalone in a hatchery, then release the juveniles into rocky reefs in the San Juan Islands. This is called outplanting. The SeaDoc Society has played a crucial role in the development of a successful hatchery program through several projects, including a genetic analysis for selection of breeding stock, a study of outplanting techniques that showed us what size abalone to outplant for best survival, and an assessment of the best habitat types for outplanting locations. SeaDoc also has funded studies to look at how juvenile abalone use urchins as a safe hiding place from predators and the merits of aggregating wild adult abalone to improve their spawning success.
Dr. Jay Dimond of Western Washington University and SeaDoc’s Mira Castle prepare for a scientific dive by Young Island. Photo by Captain Nate Schwarck.
Unfortunately, we are still a long way from recovery after years of hard work, but organizations in the Salish Sea aren’t giving up hope-- today we are ramping up pinto abalone restoration through larger and smarter hatchery and outplanting efforts, thanks to the data collected with science. In SeaDoc Society’s first funded project this year, Dr. Jay Dimond of Western Washington University will study a super cool way to detect where other abalone are in the wild before outplanting, using environmental DNA (e-DNA). With luck, this will help get hatchery-raised abalone close to their wild friends and increase the chance of abalone babies. Good luck Jay!