B.C. has unveiled an action plan to tackle the two greatest climate threats to the ocean, coastal communities and marine ecosystems on the West Coast.
Ocean acidification and hypoxia (OAH), or plummeting oxygen levels, that often occur in tandem with a snowball effect, are spiking due to human-caused greenhouse gas emissions.
The plan’s goals include strengthening scientific collaboration and research and public awareness on these issues. Finding ways to adapt to or mitigate the negative impacts of OAH is also a priority.
The province also wants a better understanding of how or if blue carbon — CO2 captured naturally from the atmosphere by marine plants and algae — could or should be used as a natural solution to buffer acidification and hypoxia.
“It’s really important we start to improve our understanding of what parts of the ocean will be vulnerable,” said Rebecca Martone, executive director of the Ocean Decade Collaborative Center, which helped shape B.C.’s OAH plan.
“These two stressors are a one-two punch to ocean ecosystems.”
The province has also allocated $2 million for a Climate Ready Seafood Program to fund projects that address the plan’s priorities — such as research that will help inform responses to OAH, or technology and practices that help the aquaculture industry adapt to the changing ocean, Martone said.
Ocean warming impacts on marine biodiversity are fairly clear, but there are knowledge gaps about the dangers OAH poses to coastal communities, First Nations and industries, Martone said.
Acidification increases as the ocean absorbs CO2 from the atmosphere. This process reduces calcium carbonate levels in the water that animals like oysters, crabs, sea urchins or coral need to develop or maintain their shells and skeletons, especially in their early life stages.
B.C. has created a new plan to tackle the twin spectres of ocean acidification and dwindling oxygen levels seen as leading climate threats for coastal communities, marine ecosystems, and industry along the West Coast.
Hypoxic dead zones, also increasingly common, can rapidly smother large numbers of bottom-dwelling creatures like crabs or shellfish that can’t escape or drive fish and more mobile marine animals from their regular habitat.
B.C. extra vulnerable to acidification and low oxygen
By 2100, the average acidity of the ocean’s surface is expected to increase by 100 to 150 per cent above levels seen at the start of the Industrial Revolution at the turn of the 19th century.
B.C.’s coast is especially vulnerable to OAH — occurring faster here than in other areas around the globe, said Martone.
The West Coast’s intricate coastline, fjord systems, complex currents and unique oceanographic conditions make B.C. waters naturally more acidic and hypoxic than other places.
But with climate change, acidification on B.C.’s coast is almost 40 per cent higher than pre-industrial levels and significantly higher than the global average of 30 per cent, the OAH plan states. Also, oxygen levels in Canada’s Pacific Ocean have dropped 15 per cent in just 60 years, exceeding the global average of two per cent.
Seafood like Dungeness crab, clams or oysters are important to First Nations’ food security and culture and commercially to fisheries and aquaculture and might be increasingly at risk, Martone said.
It will be important to determine which areas are hot spots for OAH and sites that might be more resilient as the climate crisis advances so communities and industries can react and adapt in the short and long term, she said.
For example, it’s not clear how acidification and hypoxia are affecting all sorts of other marine species, like rockfish or lingcod, both important to First Nations and commercial fisheries, she said.
Identifying areas on the coast that will be badly affected or more resilient to OAH over time would help policymakers, coastal communities and fisheries make decisions about harvesting, aquaculture and what to protect and where, she added.
Seeding a future for B.C.'s shellfish industry
The aquaculture industry also helped create the new OAH plan, said Nico Prins, executive director of the BC Shellfish Growers Association.
The industry, with help from research partners and the province, has already begun developing and putting mitigation processes in place, Prins said.
“A couple years ago, we started a breeding program to select shellfish naturally resistant to typical climatic changes,” he said.
“We also have some new husbandry practices and operating procedures that we've tested and implemented to help build more tolerant or resistant animals.”
Acidification poses the greatest risk for baby oysters during their larval stage when they just begin to formulate their shells and are on the road to becoming “seed oysters”, which are then shipped to shellfish farms to grow out.
Other climate issues pose threats to adult oysters, he said. Summer mortality events occur when excessively warm ocean water triggers the growth of harmful bacteria or toxic algae, causing a massive die-off of market-ready animals.
The selective breeding program and other new farming measures seem to be easing the problem, he said.
Developing new breeding programs for other shellfish like scallops or mussels to withstand climate impacts and establishing a reserve oyster “seed bank” are two things that would help the industry when the action plan and seafood program get underway, Prins said.
The “seed bank” would see hatcheries grow extra young oysters and hold them in reserve each year for farmers that experience catastrophic losses from a summer mortality event.
“We could provide … that seed to farmers that suffered losses so that they can essentially have an income again in a year or two and not suffer a very, very long period of needing to rebuild stocks,” he said.
Oysters make up 80 per cent of B.C.’s shellfish industry, Prins said.
New breeding programs to revive mussels and scallop farming — which took big hits from disease and die-offs in the past — and making them more resilient to climate change means growers wouldn’t have to put all their eggs into one basket, he said.
“We’re asking for support and frameworks to build the industry around a bigger diversity of species than just oysters as it stands now.”
However, the measures and goals in the province’s OAH plan or the seafood program are not alternatives to the critical need to drastically cut greenhouse gas emissions at the provincial, national and global levels, Martone said.
“We need to be reducing emissions. These [initiatives] are not meant to replace that important pathway,” she said.
“But in the meantime, we also need to be creating strategies for adaptation and mitigation at the local scale.”
Rochelle Baker / Local Journalism Initiative / Canada's National Observer