Climate changes and BC’s oceans – responding with no regrets
Three years in the making, the report “Climate Change Impacts and Vulnerabilities in Canada’s Pacific Marine Ecosystems” was released this week by WWF and CPAWS. The report consulted researchers and scientists in order to synthesize a vast amount of information so that we can understand what is changing in the Pacific Ocean of Canada. The report is meant both to inform marine resource users and managers in Canada’s Pacific, and to spur action on how to best respond to the effects of climate change in our region.
Climate change is no longer just limited to melting ice-caps and sinking islands in faraway lands. The report finds that here in British Columbia, ocean temperatures are generally increasing, and the ocean in our corner of the world is becoming more acidic and has less oxygen now than it had before. Patterns of rainfall and snow-melt on land are changing, affecting what flows into the ocean and when it flows into the ocean. Increased frequency of storms and sea-level rise are eroding shoreline and shoreline habitats on some parts of the coast.
All these changes are affecting species, habitats, ecosystems and how they interact, and they will continue to do so. Some of these changes will be detrimental. And then there are the surprises and changes that we don’t know about. The question is: What will these changes mean? Will the diverse ecosystems we have now persist into the future as things change?
We know that the increasing acidity is already affecting the growth and reproduction of shellfish like mussels and oysters. The water is too corrosive for their larvae to form shells – think osteoporosis. This is not just a concern for shellfish, but for all the marine organisms that use calcium as part of their body structure, ranging from microscopic plankton to centuries-old deep sea corals that are common off of our coast.
The depletion of oxygen in deeper habitats is having a suffocating effect, displacing groundfish species (many of which are commercially important) from their habitats. Changes in temperature are shifting the ranges of species that inhabit BCs waters – some species are extending their ranges northward and becoming more common, like sardines, while others, like certain species of salmon, will decline as they are no longer able to tolerate the warmer conditions.
Shoreline habitats such as eelgrass, sandy shorelines and coastal wetlands, that are critically important to a wide variety of juvenile species and forage fishes, are susceptible to changing sea-level, erosion, and changing flow from land. We know from previous work that areas such as the strait of Georgia that are already heavily impacted from human activities from land and in the ocean are suffering additional stress due to climate change.
Responding to climate change is no longer just about reducing emissions, although this of course remains critically important. It is now also about being able to anticipate changes, and about being able to help proactively facilitate actions that help ecosystems adapt to change and reduce the risk of their loss in a changing climate.
Being able to reduce vulnerability is a key response to these climate changes. We can maintain our ecosystems in a healthy state by being careful about how we use them, reducing our pressure on them, and establishing networks of marine protected areas – these all confer marine ecosystem health and resilience that enables them to better withstand or adapt to climate change.
Continued monitoring of the health and condition of our ecosystems along with key indicators of climate change can inform us about what further responses may be needed. Monitoring can also point to places and areas that are changing less, or that are more geographically protected and can serve as refuge areas from acidic or oxygen-depleted water. Such areas can help us “buy time” and ease the transition for some species to the climate changes. It is key that we identify and protect such climate refugia so that they can serve this function. We can take all these actions with no regrets.