Skip to main content

The Globe and Mail

Death of B.C. sea stars reveals ecological domino effect

Hundreds of sea stars were found washed up in Trail Bay on the Sunshine Coast.

DUANE BURNETT/CP

The mass death of sea stars in British Columbia's Howe Sound has created a trickle-down effect that a researcher says should be a warning about the depletion of any species in the ocean.

Sea stars began dying by the millions in waters from Alaska to Mexico in the summer of 2013.

Experts still don't have a conclusive cause, but have linked some deaths to a virus and others to fluctuating water temperatures, said Jessica Schultz, a master's student at Simon Fraser University and the Vancouver Aquarium's Howe Sound research program manager.

Story continues below advertisement

"It's difficult to prevent further disturbances like this when you don't fully understand what the cause was," she said in an interview Wednesday.

Schultz and fellow marine ecologists Ryan Cloutier and Isabelle Cote from Simon Fraser discovered that the deaths in the Howe Sound, just north of Vancouver, triggered a rapid rise in the number of green sea urchins and a depletion of the kelp they like eat.

The sunflower star, one of the star fish most affected by the wasting disease, was a voracious predator of the urchins. At the same time, kelp has declined by 80 per cent.

Cote says the upheavals in the food chain are a sign of an ecological domino effect.

"It's a stark reminder that everything is connected to everything else. In this case, the knock-on consequences were predictable, but sometimes they are not," she said in a news release.

Schultz said there is still no sign of recovery for Howe Sound's sea stars. In fact, they are still dying.

There has been talk of listing some of the star fish as endangered, she said, including the sunflower sea star, among the largest sea stars in the world.

Story continues below advertisement

The loss of that predator put things out of whack, Schultz said.

"The more we can try to maintain ecosystem integrity in whatever system it is, the better systems will be able to recover from things like this," Schultz said. "Everything is connected."

Report an error
As of December 20, 2017, we have temporarily removed commenting from our articles. We hope to have this resolved by the end of January 2018. Thank you for your patience. If you are looking to give feedback on our new site, please send it along to feedback@globeandmail.com. If you want to write a letter to the editor, please forward to letters@globeandmail.com.