Near Dallas Road in Victoria, the waters hold thriving kelp forests below the surface due to the consistent cold temperatures. However, in various parts of British Columbia, there are localized warm pockets known as microclimates where kelp populations have dwindled. Brian Timmer, a PhD student at the University of Victoria, highlighted this finding from a recent study published in Ecological Applications.
Timmer’s research team utilized historical data from the northern Salish Sea to track the decline of kelp and associated macroalgae communities. Comparing data dating back to 1972 with recent surveys in 2023 revealed a significant loss of bull kelp forests, particularly around the Comox and Denman Island region. The study indicated that over 5.5 million square meters of kelp forests once covered the area, which was ten times more than previously estimated around the year 2000.
Satellite imagery showed the rapid disappearance of these kelp forests between 1972 and 1984, with the study suggesting that major losses occurred before recent heatwaves, such as the “Blob” heatwave from 2014 to 2016. The research pinpointed a warm water pocket near Comox and Denman Island as a significant contributor to the decline, experiencing some of the highest ocean warming temperatures globally.
Over the past five decades, sea surface temperatures at the Chrome Island lighthouse have risen by 0.25 degrees Celsius per decade, leading to a total increase of 1.66 degrees Celsius. This accelerated warming poses a significant threat to kelp populations, which play a crucial role as foundation species and primary producers in marine ecosystems.
William Cheung, a professor at the University of British Columbia, emphasized the importance of establishing accurate baselines to understand environmental trends and guide conservation efforts. The study revealed substantial declines in sugar kelp and red bladed algae since 1972, attributed to the warming waters along British Columbia’s coast.
Timmer is actively involved in initiatives like the Kelp Rescue Initiative and collaborates with First Nations to restore kelp forests in the region. By identifying suitable habitats and replanting kelp species, efforts are underway to protect and revive these vital marine ecosystems.