Annual air temperatures in the Central Coast sub-region are expected to increase by approximately 1.6°C by 2050, which is similar to the current temperatures experienced in Vancouver [10,36,42] (see Central Coast Sub-regional Table). Summer precipitation is also predicted to increase in this sub-region, leading to increasing freshwater discharge will also contribute to stronger flows in Hecate Strait [21,42,73].
Changing precipitation patterns means that streamflow patterns are likely to change, such that summer stream flow is lower, with associated impacts to salmon and other anadromous or freshwater fish. It is possible that low flow conditions within the watershed could occur over the entire year, though generally they are likely to occur during the late fall and early winter. Within the context of future climate changes and related vulnerabilities of freshwater habitats, changes in the frequency, timing, and magnitude of such low flow conditions may have greater effects on salmon migration, spawning, and incubation than at present.
Sea levels are projected to increase within the Central Coast sub-region, but not as much as other sub-regions. Some specific impacts at the scale of the Central Coast sub-region are due to sea level rise and extreme weather events. Sea levels near Bella Bella are projected to rise by approximately 9 cm by 2100 (range -5.4 to 22 cm) (Thomson et al. 2008). However, localized land uplifting (+2.3mm per year) means that overall, the Central Coast sub-region is not likely to experience net negative impacts from sea level rise in the foreseeable future .
There are some cultural and historic sites that may be particularly likely to be affected by rising sea levels based on recent shoreline sensitivity analyses and locations of historic First Nations sites (see Central Coast Archaeological Sites Shoreline Sensitivity Map).
Sea surface temperatures are expected to increase by ~1.9°C by the latter portion of the century, with impacts to fisheries and communities through loss of fisheries landings and adjustments in fishery target species. Ocean acidification will increase, affecting calcifying organisms and the aquaculture industry. These changes will likely affect coastal communities, especially First Nations communities who rely on bivalves and other shellfish for food security and income.