Near the coast along Dallas Road in Victoria, the ocean harbors lush kelp forests just below the water’s surface. Brian Timmer, a PhD student at the University of Victoria (UVic), mentioned that these kelp forests thrive due to the consistently cold water in the area. However, as you move to different regions in British Columbia, there are localized areas of warming known as microclimates where kelp forests have vanished.
A recent study led by Timmer from UVic, published in the journal Ecological Applications, revealed the disappearance of once abundant kelp forests in the northern Salish Sea. By analyzing historical data dating back to 1972 using maps, scuba surveys, and aerial photos, Timmer’s research team found that over 5.5 million square meters of bull kelp forests used to cover the surface near the Comox and Denman Island area. This is ten times more than the previously estimated baseline set around 2000, which no longer exists today.
Satellite imagery indicated that the loss of bull kelp forests occurred primarily between 1972 and 1984, with a significant decline within just 12 years. Timmer’s study challenged the notion that recent heatwaves, such as the “Blob” heatwave from 2014 to 2016, were solely responsible for the disappearance of B.C.’s bull kelp forests. Instead, the research focused on a warm water pocket within the Strait of Georgia near Comox and Denman Island, ranking among the top 10% of global ocean warming temperatures.
Over the past five decades, sea surface temperatures at the Chrome Island lighthouse, situated off Denman Island’s southern tip, have increased by 1.66 degrees Celsius, with an accelerated warming rate of 0.25 degrees Celsius per decade. Such rapid warming periods are detrimental to kelp populations.
Kelp, considered a foundation species and primary producer, plays a crucial role in marine ecosystems by providing food and habitats for various sea creatures. The decline in kelp and red bladed algae populations since 1972 is attributed to the warming waters along the B.C. coast, as indicated by UVic researchers.
To address this issue, Timmer collaborates with the Kelp Rescue Initiative and First Nations to restore kelp forests in British Columbia. Protecting critical areas and implementing long-term kelp habitat restoration strategies are essential steps in combating the decline of these vital marine ecosystems.
