Photo: Will Husby
Changing Climate
Rising Sea Levels and Intensifying Winter Storms
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As the ocean gets warmer, causing seawater to expand, the level of the sea rises. Melting land-based ice sheets and glaciers, contributing their own water, cause oceans to rise even further. The BC government advises to plan for a one metre rise by 2100 and two metres by 2200. Rising sea levels will damage coastal structures (including homes and docks) and erode the shoreline. Rising water levels at the shore also cause the loss of wildlife habitat and biodiversity.
Extra heat in the air and the oceans is a form of energy, and storms are driven by such energy. The Bay, already subject to winter ocean storm surges, will likely see an increase in the intensity and the frequency of big winter storms that can cause major shoreline erosion.
Property owners often attempt to prevent erosion by removing shoreline native plants and trees and adding seawall, rip rap, and docks (armoured shoreline structures), altering Kwilákm’s natural shoreline.
Ecological understanding of these alterations to the shoreline has changed. Long viewed as relatively benign changes to the shoreline, current science shows that armoured structures cause the loss of wildlife habitat and biodiversity and do not provide protection. Researchers have determined that, in many cases, armouring shorelines will actually increase rates of erosion.
Removal of native trees, shrubs, and vegetation just above the high tide line results in habitat loss for clams and other shellfish, as well as insects, worms, and amphipods that feed forage fish and young salmon. These forage fish and salmon ultimately feed animals at the top of the food web that connects zooplankton, eelgrass, and kelp to salmon, white-sided dolphins, orca, sea lions, and porpoises. What we do on our shores ripples through the food chain.
Green Shores from the Stewardship Centre for BC provides online guides to assist homeowners to understand and protect shoreline forest while also protecting and restoring habitats.
Green Shores use a combination of planting, gravel and sand, logs, stones, and slope modification to protect against shoreline erosion. The natural actions of water and sediment movement maintain healthy shorelines while providing habitat for a diversity of plants and animals.