New research out of the University of New Brunswick has revealed how seaweeds of Haida Gwaii may be more closely connected to California than to nearby Vancouver Island. The findings support the theory that the Kelp conveyor carries seaweeds north to Haida Gwaii.
The study, published Sept. 7 in the journal Diversity by Cody Brooks and Gary Saunders, tested the “kelp conveyor hypothesis” — the idea that non-buoyant algae hitch rides north on drifting kelp rafts torn loose in central California, contributing to the Kelp conveyor carries seaweeds north to Haida Gwaii.
Using genetic data from 11 species of red algae collected in California, Haida Gwaii, and southern Vancouver Island, the researchers found strong support for the theory. Nine of the 11 species showed low genetic differences between California and Haida Gwaii, and 13 per cent of alleles found on Haida Gwaii were disjunct, meaning they were shared only with California and absent from Vancouver Island.
“Kelp rafts dislodged in California can drift north on the Davidson current for months at a time,” Brooks explained. “That opens up a pathway of gene flow that doesn’t follow the usual isolation by distance we expect in marine species.”
The research helps explain why many algae once thought to be unique to Haida Gwaii have also been collected much farther south. Previous surveys by Saunders recorded 33 species initially believed to be endemic to Haida Gwaii, but later confirmed in California. The new genetic evidence strengthens the case that kelp rafting is the missing connection.
The findings also complicate the story of biodiversity on Haida Gwaii, which has long been attributed to ancient glacial refuges and modern barriers such as Queen Charlotte Sound. While those forces remain important, the kelp conveyor shows that Haida Gwaii’s marine ecosystems are also shaped by long-distance arrivals that defy geographic boundaries.
For Haida Gwaii, the results highlight an overlooked source of resilience. Kelp rafts don’t just carry passengers — they deliver fresh genetic material that can help species adapt and diversify, adding to the strength of local ecosystems.
Although the study focused on red algae, the researchers say the process likely extends to other forms of marine life. Kelp rafts have been documented carrying hundreds of species, from invertebrates to small fish, and can drift for months before breaking apart. For Haida Gwaii, that means the kelp conveyor may be a quiet but powerful current of connection linking the islands to distant shores.
