Underwater gardeners work to restore B.C.'s crucial kelp forests

In the chilly waters of Vancouver Island's Barkley Sound, gardeners are at work on the sea floor.

They are scientists from the University of Victoria (UVic) who are trying to regrow kelp forests, a crucial part of the marine habitat, amid threats from heat waves, climate change and voracious sea urchins.

Julia Baum, a UVic professor of ocean ecology and global change, has been studying data going back decades on British Columbia's majestic underwater forests, which provide food and resources for fish and other coastal organisms. 

She said a "very prolonged marine heat wave between 2014 and 2016" had a major impact on the northeast Pacific Ocean.

"What we found was that in a number of places, kelp forests disappeared," said Baum. 

Bull kelp and giant kelp, the two main canopy-forming kelp species found in marine nearshore habitats off Canada's West Coast, "were disappearing in areas that really became abnormally warm during this long, extended heat wave," she said. 

The realization prompted a four-year project on kelp forest restoration, funded by $3.68 million from Fisheries and Oceans Canada. The project is now well into its second year, with researchers teaming up with First Nations to grow kelp in nurseries in the waters of Barkley Sound, off Bamfield, B.C.

But the science of kelp restoration is still in its infancy, said Baum.

Different from vegetative plants that put down root into soil, kelp instead uses a structure called a "holdfast" to clasp onto rocks.

She said her group had been experimenting with planting young kelp on various materials, such as different-sized rocks or gravel, "to try to see what will take the best."

Reforesting ocean floors with kelp is "challenging work," she said, with divers having to plant the kelp, monitor its growth, and measure its hardiness in different conditions.

"So, these are really large-scale manipulative experiments ... It's kind of like replanting a forest, reforesting an area," she said.

A statement from the university said collaborators include the Huu-aye-aht First Nations and other First Nations, the western Canadian Universities Marine Sciences Society, Pacific Salmon Foundation, Genome B.C., the Hakai Institute, West Coast Kelp and other groups.

Connie Crocker, the project's First Nations liaison, has been building relationships between the scientists and First Nations to apply Indigenous knowledge and expertise to the kelp restoration project.

"The road map to kelp recovery is through awareness. It's all about awareness — there's strength in numbers," she said in the statement.

"We need the public behind us … it's urgent and the ocean is in peril. If only people knew about kelp decline, we could make some headway."

Baum said the project was urgent and she could feel the "drive and momentum" to protect the kelp forests.

"Restoration projects often take a very long time to become successful because it is challenging work," she said.

"But we're approaching it in a really rigorous scientific manner, and so I'm hoping that we can make good progress and actually make a difference for kelp forest ecosystems on our coast."