Aquarium of the Pacific trying to preserve underwater forests
Bull kelp has been on decline because of warming waters, food chain disruption
Bull kelp — while unassuming — is an essential fixture in the marine ecosystem up and down the West Coast.
Its expansive underwater forests provide protection for vulnerable sea creatures, including sea urchins, starfish, otters, crabs and snails. Many sea creatures rely on bull kelp as a food source. Bull kelp also helps out humans, thanks to its plentiful oxygen production, and it protects the coasts from erosion and other damage caused by waves.
The kelp, though, is in dire straits. It has faced mass destruction recently, threatening the marine ecosystem, but the Aquarium of the Pacific has swooped in to help.
The aquarium has partnered with the University of Wisconsin at Milwaukee and California Sea Grant, an organization that provides funding for marine and coastal research, to create a preservation project.
A combination of events in 2014 — including an underwater heat wave and an explosion in the sea urchin population — resulted in the destruction of more than 95% of Northern California's bull kelp forests, according to the National Science Foundation.
“That really was the first event that took out a lot of the northern bull kelp,” said Jessica Soski, a senior aquarist in the Aquarium of the Pacific's Northern Pacific Gallery. “The big (challenge) is going to be climate change — kelp needs very specific conditions to reproduce and to live, and the warmer water is really hard on it.”
But there are other problems, Soski said: About the same time as the underwater heat wave, sea stars along the Pacific coast began to die off en masse
“In case we have catastrophic events that take out all the bulk kelp, we (can) go back to these libraries ... use that for future restoration work.”
— Jessica Soski, senior aquarist in the Aquarium of the Pacific's Northern Pacific Gallery
because of a little understood condition called sea star wasting disease. Sea star population levels remain low — resulting in a dramatic increase of their natural prey, sea urchins.
“So what can happen is the urchins get out of balance when their predator is taken away,” Soski said, “and then they eat all of the kelp.”
Satellite images taken by the National Science Foundation in 2021 show that the once plentiful kelp forests along the Northern California coast have been nearly completely replaced by sea urchin barrens.
The preservation project the Aquarium of the Pacific is part of what is hoped to be a help in reversing some of the damage by collecting genetic material from the kelp forests.
“We're going out and collecting it now and basically trying to save it for later,” Soski said. “In case we have catastrophic events that take out all the bulk kelp, we (can) go back to these libraries that we have of the genetic material and use that for future restoration work.”
Aquarium of the Pacific staff will preserve 1,400 bull kelp genetic specimens, according to a Wednesday news release. Those genetic materials, or gametophytes, will be stored in stasis at the aquarium, where they can be preserved for decades.
“Unlike most plants that just drop seeds that grow into a new plant, kelp release spores and then those spores settle on the ocean floor,” Soski said. “Those spores can be basically turned into either a tiny little microscopic male or a tiny little microscopic female, and that's what we're holding in our test tubes.”
Once preserved, the kelp specimens can be extracted and planted into the ocean to hopefully repopulate decimated kelp forests in the future. The University of Wisconsin at Milwaukee, Soski said, also has its own library of bull kelp genetic material, so there is a backup should anything happen to either preservation project.
“It's a very hopeful project,” Soski said. “In a perfect world, we wouldn't need to use these, but we have them in the event that we do.”