U of G Study May Boost Survival of Threatened Sea-Dwellers
May 11, 2012 - News Release
A new study by University of Guelph researchers offers hope for recovery of an endangered marine snail on Canada’s West Coast that has been depleted by overfishing, mostly for foreign sushi restaurants.
Genetic analysis suggests that northern abalone snails spawned in hatcheries can survive and repopulate depleted waters off the British Columbia coast, said integrative biology professor Elizabeth Boulding.
She and her former Guelph students Kaitlyn Read, Stephanie Acheson and Matthew Lemay authored a paper published last month in the journal Conservation Genetics.
The team found that hatchery-reared snail larvae and juveniles released, or out-planted, along the coast thrived, although not at high enough densities to restore populations. The endangered snail lives in shallow intertidal areas from Alaska to the California Baja.
“There’s merit in reintroducing abalone to some of these areas, and our study shows that out-planting can happen at the larval stage,” said Boulding.
Northern abalone snails are considered a delicacy in Japan. Their ear-shaped shells are lined with mother-of-pearl and are used in traditional carvings by First Nations.
Not only have natural populations dwindled, but also the remaining male and female snails are so dispersed that spawning is difficult, further threatening survival.
Despite fishing bans, poaching of lucrative abalone is a continuing threat. Natural predators include sea otters and invertebrates such as starfish and crabs.
The researchers worked at the Bamfield Marine Science Centre on the west coast of Vancouver Island.
Between 2002 and 2005, Bamfield volunteers released hatchery-raised larvae and juveniles into Barkley Sound. Before the Guelph project, they didn’t know whether the out-planted snails had survived.
The researchers took small tissue samples from snails collected from those areas before returning them to the ocean floor.
At Guelph, the team used DNA from the samples to match the animals with hatchery parents and siblings. Hatchery-reared stock made up about one-quarter of the sampled snails.
The researchers recommend more frequent out-planting to increase population density and raise the odds of mating success. New out-planting methods are needed to improve abalone survival, including use of cages and cobble substrates to favour abalone and deter predators, said Boulding.
She remembers collecting abalone shells while growing up on eastern Vancouver Island. “Whenever you went for a walk after a big storm, you found their iridescent shells washed up on the beach.”
Boulding’s abalone studies were funded by the Natural Sciences and Engineering Research Council under a project with researchers from Thompson Rivers University, the University of British Columbia, and the federal Department of Fisheries and Oceans.
Former U of G graduate student Kaitlyn Read and her dive buddy from TRU, Christine Hansen (left)
Contact:
Prof. Elizabeth Boulding
Integrative Biology
519 824-4120, Ext. 54961/58156
boulding@uoguelph.ca
For media questions, contact Communications and Public Affairs: Lori Bona Hunt, 519-824-4120, Ext. 53338, or lhunt@uoguelph.ca, or Shiona Mackenzie, Ext. 56982, or shiona@uoguelph.ca.
