By Allan Crow
IB次元官网网址檝e spent over 35 years fishing and diving for a living in the receiving waters of the Capital Regional DistrictB次元官网网址檚 untreated sewage discharges and have witnessed their degrading effects. Once vibrant local marine environments are now shadows of their former diversity.
Those discharges appear on the local seabed, reefs, and even the marine life itself in the form of a fine grayish brown sediment with a grotesque B次元官网网址榓dhesiveB次元官网网址� quality. Visible accumulations appear at around 50 feet and intensify the deeper you go. Vast areas of the local seabed have been exposed, particularly where conditions are favourable for the accumulation of sediments.
This impact can be understood by examining how tidal currents actually circulate within the confined waters of the Victoria Bight, which is described in The Current Atlas for Juan de Fuca Strait published by the Canadian Hydrographic Service.
During the ebb tide, the current flows weakly, often less than one knot over both outfalls. The discharges trundle west toward Colwood and Metchosin, where the land mass deflects the current southward. As the discharges approach Race Rocks, the tide changes, the current reverses and heads north B次元官网网址� straight back towards Victoria.
Recent CRD sampling of seabed sediments, collected on a transect from the Macaulay Point outfall travelling south about halfway to Race Rocks, revealed very high levels of seabed fecal coliform contamination.
On flood tides the discharges are pushed east toward Trial Island, then northeast through and around the islands off Oak Bay and into southwestern Haro Strait, exposing the entire seabed throughout this area. By the time the effluent travels into lower Haro Strait the tide changes, the current reverses and pushes it right back through Oak Bay towards Victoria.
In my experience, the visible footprint of the CRDB次元官网网址檚 outfalls extends from slightly west of Race Rocks all the way around to the Gordon Head area in Haro Strait.
ItB次元官网网址檚 sadly ironic that Trial Island, the Chain Islands off Oak Bay, parts of Discovery Island, Ten Mile Point and Race Rocks are ecological reserves supposedly created for the benefit of conservation, yet their submarine environments are exposed to the CRDB次元官网网址檚 chemical- and microbe-laden sewage discharges.
A sanitary closure restricts the harvest of shellfish over a vast area of the local seabed. To ensure public safety, the recreational harvest of deep dwelling swimming scallops is prohibited in all of area 19, which stretches from Race Rocks to Sidney. The scallops are filter-feeding on the sewage discharges and are unsafe for human consumption.
Modern sewage waste streams contain many harmful pollutants and toxic chemicals, the bulk of which are entrained within the solids and sludge that would be removed during the sewage treatment process.
These include pharmaceuticals and other persistent chemical compounds such as flame retardants and microplastics. Much of the microplastic is derived from petroleum-based textile fibres from laundry discharges.
Untreated sewage also contains huge loads of viral and bacterial pathogens, some of which can survive for long periods of time in the marine environment.
Recent studies confirm our Southern Resident killer whales have been exposed to over 25 human-sourced pathogens and may well be the most chemically contaminated population of whales known to science.
For those interested in reviewing some quality science regarding bio accumulation and food web contamination in our local marine environment, watch B次元官网网址淧rotecting BCB次元官网网址檚 Marine Mammals from Land Based PollutionB次元官网网址� posted on Youtube by the Vancouver Aquarium.
IB次元官网网址檇 like to see the degradation reversed in my lifetime. Sewage treatment is long overdue.
Allan Crow is a former commercial fisherman and diver living in East Sooke. Between 1978 and 2013 he dove in local waters harvesting octopus and collecting specimens for local marine aquariums including Undersea Gardens, Sealand and the Shaw Ocean Discovery Centre.
