Some Climate Change Projections and Impacts on Fisheries and Aquaculture within coastal BC
Table 1: Summary of climate impacts on key fisheries in the north Pacific and British Columbia [92,160].
| Fisheries species of interest | Ecological variable affected by climate change | Probable impacts |
|---|---|---|
| Sablefish (Anoplopoma fimbria) | Ocean temperature | May negatively affect egg, larval and juvenile survival. Declining ocean productivity may affect recruitment. Overall: Climate change over the next 50 years may not impact adult sablefish or long term population dynamics. Projected change in relative abundance of -9 to -11% by 2050. |
| Pacific herring (Clupea pallasii) | Ocean temperature | Herring ocean habitats will be affected. Predation from increasing populations of Pacific hake may affect herring populations. Overall: Abundance is projected to decline by 32-49% by 2050. |
| Pacific hake (Merluccius productus) | Ocean temperature | Hake biomass may increase. More migration into northern range (BC waters) Overall: Abundance may increase. |
| Pacific halibut (Hippoglossus stenolepis) | Ocean temperature | Overall: May reduce recruitment. Projected change in relative abundance of -12 to -13% by 2050. |
| Pacific ocean perch (Sebastes alutus) | Ocean temperature | Overall: Recruitment may decline if Aleutian Lows decrease. |
| Pacific sardine (Sardinops sagax) | Ocean temperature Oceanographic conditions | Unlikely to impact or unknown projected change in relative abundance of 33-44% by 2050. |
| Pacific cod (Gadus macrocephalus) | Ocean temperature | Likely to severely deplete populations by reducing or eliminating recruitment. Projected change in relative abundance of -13 to -35% by 2050. |
| Pink salmon (Oncorhynchus gorbuscha) | Ocean temperature River temperatures Oceanographic conditions | Overall: Abundance is likely to decline, particularly for southern populations. Projected change in relative abundance of -40 to -44% by 2050. |
| Sockeye salmon (Oncorhynchus nerka) | Ocean temperature River temperatures Oceanographic conditions | Mortality is likely to increase during all life stages when exposed to warm water temperatures. Overall: Abundance is very likely to decline, particularly for southern populations. Projected change in relative abundance of -10 to -36% by 2050. |
| Chum Salmon (Oncorhynchus keta) | Ocean temperature River temperatures Oceanographic conditions | Mortality is likely to increase, but uncertainty is high. Overall: Abundance is likely to decline, particularly in the southern portion of the coast. Projected decline in relative abundance of 10-12% by 2050. |
Table 2: Summarized key risks and knowledge gaps related to ocean acidification (OA) [52,63]
| Species | Details | Sectoral impact | Uncertainty or opportunity |
|---|---|---|---|
| Shellfish | Shell formation will be negatively affected by OA Increasing toxicity of harmful algae blooms | Fisheries and aquaculture | Wild shellfish may be more able to adapt than farmed. No studies yet on geoduck clams. Likely to be increasing shellfish closures, Potential for decreased reproductive success and mass mortality at higher trophic levels (predators) including fish, seabirds, marine mammals |
| Salmon (farmed Atlantic salmon, Salmo salar) | Algae blooms are likely to increase (fish killing alga Heterosigma akashiwo) | Fisheries and aquaculture | High uncertainty |
| Food web dynamics | Changes in species composition of phytoplankton’s Decline of pteropods Potential decline of echinoderms Observed behavioural changes at various trophic levels e.g. decreased predator avoidance in larval fish Potential behavioural changes at various trophic levels, e.g. increased movement to refugia, eelgrass meadows | Ecosystems Fisheries and aquaculture | High uncertainty Likelihood of impacts at higher trophic levels (fish) e.g. Pink salmon (Oncorhychus gorbuscha). Likelihood of impacts to predators e.g. rockfish and flatfish. Significant knowledge gaps. |
| Algae | Changing algal species e.g. upright macroalgae may shift to algal turf. This will change habitats for juvenile fish Declining coral species (especially octocorals) Seagrasses are likely to benefit from increased carbon, but increased grazing will have negative effects. Net effect will be neutral for seagrasses. | Fisheries and aquaculture Ecosystems | High uncertainty |
| Finfish | Potential difficulties with olfaction (sense of smell), osmoregulation, and cardiorespiratory control Direct negative impacts (reproduction, growth rates, survival) at high levels of carbon dioxide | Fisheries and aquaculture | High uncertainty Minimal research Significant knowledge gap |
| Crustaceans | Crabs may be negatively affected Juvenile stages of all crustaceans are more vulnerable | Fisheries and aquaculture | Significant knowledge gap |
| Marine mammals | Ocean acidification may lead to a ‘noisier’ ocean which could impact marine mammals | Ecosystems | Uncertainty exists |
Unknown/not studied: Cold water corals (Octocorals), glass sponges