Scientists in Nova Scotia combatting climate change by using gravel to regrow ocean kelp

Sea kale, seaweed, saccharina latissima, phaeophyceae, laminariaceae. Brown ocean algae, sugar kelp thallus or sea belt on stones A type of sugar kelp, though this one wasn't grown in a shipping container! Photo by Anghi/Shutterstock

Some specially engineered gravel may be the key to restoring Canada’s depleted kelp beds, turning the tide for a species crucial to ocean health. 

A team of researchers in Nova Scotia have seen early success working with “green gravel,” small rocks used as a surface to grow sugar kelp, a species that has thinned out in the province’s waters due to the impacts of climate change. The seedlings are currently being stored in a special shipping container before the team plants them temporarily into existing kelp beds off of Mahone Bay to see if they continue to grow.

Cascadia shipping container where the research team is growing sugar kelp
Photo by Cascadia Seaweed

Kelp, technically a type of algae, is an essential part of the ocean’s ecosystem, as it provides habitat for other species and can also pull excess, potentially harmful nutrients from the water, helping maintain a delicate balance. However, with warming waters and a decline in the overall health of our oceans, there’s been a thinning of kelp beds in Nova Scotia and elsewhere in Canada. 

The project, a collaboration between the National Research Council (NRC), the Ecology Action Centre in Halifax, Cascadia Seaweed, and Quebec-based industrial marine research company Merinov, could have implications for depleted kelp beds across Canada. Flora Salvo, a researcher with Merinov, is also working with the NRC to create a bank of kelp seeds that have shown resilience and adaptability. “The idea of developing a bank is for any [kelp] farming activities to have the potential for seeds to be available at any time,” she said. “If there is a place where the population is starting to decline, then we’d already have the genetic print of it, and we can hopefully grow them from there.”

Merinov was asked to partner with the green gravel team given their expertise in other types of seaweed farming and restoration. Salvo and Stephen O’Leary, a lead researcher with the NRC, helped develop the plan with the Ecology Action Centre, whose team also brought previous expertise with algae conservation. 

Salvo said while the green gravel technology is exciting, she hopes the main takeaway from this project is the value of open, generative collaboration. With private industry, government, and local action groups all having a seat at the table, Salvo points out how the mix of expertiseand shared goal of conservationhas contributed to the successes. “Having different backgrounds really added to the possibility of being able to restore the area, especially with species like sugar kelp, which provides support and life for a lot of organisms,” she said. “To fight climate change might be difficult, but when you have any damage to the environment, the capacity we have for restoration of the ecosystem is really important.”

This story has been updated to clarify that the kelp will reside temporarily in Mahone Bay.

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