Climate change trends have in turn affected coastal ecosystems and economic sectors in BC. As of 2017, some observed impacts that may be associated with climate change trends include both general and specific examples.
Changing ocean temperatures affect marine species, ecosystems, and the human communities and economic sectors that depend on marine resources. Warming ocean temperatures have been observed with associated impacts on the marine ecosystem and fish, for the past several decades . Increasing sea surface temperatures and declining oxygen levels have affected the northern Pacific Ocean, which has likely led to reduced habitat availability and decreased survival for many fishes and invertebrates .
Harmful algae blooms during the 2015 ‘warm blob’ event could also be associated with climate warming . During that event, warm water zooplankton were much more abundant than cold water species in 2016. Changing zooplankton species has potential implications for fish, as warm water zooplankton species have lower nutrient quality . Other unusual biological events during that anomalously warm water period included low chlorophyll levels (2014), potentially due to increased stratification and reduced nutrients . This mass of abnormally warm water has since dissipated (in 2016) .
Abnormal warm water species sightings that could indicate dramatic species range shifts include sightings of ocean sunfish and warm water sharks off Washington State and Alaska, high catches of albacore tuna off the Washington and Oregon coasts, juvenile pompano sightings near the Columbia River, and widespread stranding of Velella velella off the coast of BC throughout the summer of 2014 .
The physical oceanographic impact of increased ocean temperature has had substantial impacts on the marine ecosystem, suggesting that long-term climate warming may have analogous ecosystem responses .
Fisheries catches and landed values have declined since the 1990s in BC . A warming trend in sea surface temperatures was detectable even several decades ago . In southern BC, the impacts of warming freshwater and marine water temperatures have been observed, leading to declining fish productivity and diminished returns of Fraser River sockeye salmon . Ocean acidification has been observed in BC, especially along the south coast [61–63]. Increasing rates of acidification are likely to negatively affect calcifying organisms, many of which are important for aquaculture and traditional food resources, including molluscs, bivalves, sea urchins, and sea cucumbers. While observations and field evidence are still limited, the interacting effects of ocean temperature and acidification is of critical concern for many taxa (e.g. molluscs, corals, calcareous algae).
- Warm sea surface temperatures have been observed, along with warm water associated species shifting north into BC waters .
- Ocean acidification has affected calcifying organisms, especially larval survival (e.g. Strait of Georgia [61–63]).
- Warm ocean temperatures, combined with summer drought, have created unfavorable conditions for salmonids. Low returns of Fraser River sockeye salmon have been observed (e.g. returns in 2016 were the lowest on record) . Fraser River sockeye were recently recommended for listing with the Species at Risk Act .
- Melting glaciers across BC may be releasing historical pollutants into freshwater ecosystems, thus affecting freshwater fish and downstream marine areas .
- Energy demands for heating have declined for buildings across BC, especially in northern BC, as average air temperatures have increased .
- Increasing storm surge events have been observed along the BC coast, along with an increasing frequency of ‘king tide’ events.
- First Nations cultural sites may be impacted by rising sea levels, storm surge, and king tide events. For example, cultural sites near Prince Rupert and Metlakatla are experiencing erosion and loss of cultural artifacts (A. Paul, pers. comm., November 24, 2017).
- First Nations communities have observed changes to seasonality of local food gathering practices .
- Increasing sea levels may be affecting coastal built infrastructure [68,69].
- Increasing frequency and intensity of storm events may affect marine infrastructure (at sea and near-shore) .