A report on BC’s coastal environment, produced by the BC ministry in collaboration with Fisheries and Oceans Canada, the University of British Columbia Fisheries Centre, and the University of Victoria Geography Department, with key contributions from Environment Canada, reveals several trends worth thoughtful consideration.
Many of BC’s ecosystems are relatively intact, particularly in the northern and central coast. Ecosystem loss is greatest on the South Coast where the human population is most concentrated. This area formerly contained some of the highest levels of biodiversity in the province, but it has been severely altered ecologically. It is likely that climate change will create additional pressure on ecosystems that are already stressed.
All results, including the full text of the papers and the data sets underlying the graphs, are available to the public on the project website (www.env.gov.bc.ca/soe/bcce/). The website provides summaries of key information and links for further reference.
Results
– Over the next 20 years, the coastal population is projected to increase by a million people.
– Sewage discharged into the Georgia Basin increased by more than 60% between 1983 and 1999. In 2004, more than half of the shellfish harvesting areas in the Georgia Basin were closed due to sewage contamination.
– Sea surface temperature has risen along the entire coast, with the North Coast and the central Strait of Georgia showing the largest increases. Deep-water temperatures have also increased in inlets on the South Coast. With the exception of areas of the coast being pushed up due to geological processes, relative sea level has risen along the coast.
– In BC, the largest source of greenhouse gas emissions comes from transportation, including commercial and private vehicles. From 1990 to 2002, greenhouse gas emissions in BC rose an average of 2.1% per year, which is less than the Canadian average of 2.8% annually. [At this rate of increase, by 2025, these emissions will have doubled from 1990 levels – Ed].
– A wide range of contaminants are detectable in BC’s coastal environment. Overall, environmental concentrations of PCBs, dioxins and furans, mercury, DDE and other organochlorine pesticides have fallen as a direct result of regulatory controls instituted in the 1970s–1990s. Except at contaminated sites, concentrations of these substances in air, water, and the general environment are low.
– Dioxin and furan levels in pulp and paper mill effluents have dropped to non-detectable levels since 1990. Environmental monitoring shows a corresponding 95% decrease in dioxins and furans in the tissue of crabs and an 85% decrease in sediment contamination near most mill outfalls. Not quite half of the area of shellfish beds closed to harvesting due to dioxin and furan contamination has been reopened.
– Persistent contaminants, such as PCBs, dioxins and furans, already in the environment continue to circulate and accumulate in animals near the top of the food chain. Southern resident killer whales are among the most contaminated marine mammals in the world.
– New industrial contaminants continue to emerge as issues, as exemplified by a new class of persistent contaminants, bromated flame retardants. Levels have been rising rapidly in the general environment and in the tissues of animals and people.
– Despite controls, there are still continuous, low-level inputs of contaminants to the provincial environment.
– As of January 2006, BC and Alberta had the largest proportion of protected areas in Canada — including recent announcements, the protected area for BC is 13.8%.
– Results of a risk assessment survey showed that experts considered that more than one-quarter of coastal protected areas were subject to high impacts from forestry, mining, and agricultural activities outside of the protected area.
– As of January 2006, 46% of the land on the northern and central coast was ecologically intact (at least 2000 ha in size and 5 km away from roads), compared to the south coast, which had only 2.8% of the area ecologically intact. A preliminary analysis found that less than 25% of the continental shelf ecoregions remains undisturbed by human activity.
l The rugged BC coast, with its complex geography of deep fiords and countless islands, is home to animals that live nowhere else. It is one of the most biologically diverse areas in Canada. Of all the species in BC, two-thirds of the mammals and three-quarters of the freshwater fish live only in the coast region. One-quarter of all remaining coastal temperate rainforests in the world are found in BC.
– In 2005, 86 coastal BC species were listed as locally extinct, endangered, or threatened by the Committee on the Status of Endangered Wildlife in Canada.
– Indicators show that the status of coastal vertebrates as a group has declined over the past 14 years; 4 new species were added to the red list, and there has been no improvement in status for most coastal vertebrates that were on the red list in 1992. Killer whales have been added to the provincial and federal lists of species at risk.
– Rare and sensitive ecosystems mapped on eastern Vancouver Island lost nearly 1400 hectares (or 5%) over the past 10 years.
– At least 629 species of alien plants occur on the BC coast and about 65% of these have become widely established. Forty-one species of vertebrates have been intentionally or accidentally introduced to coastal BC.
– Overall, although there are conservation concerns for some populations or stocks of fished species in BC, many appear to be doing well with an estimated 81% of the salmonid populations in BC (outside of Strait of Georgia) and the Yukon, at no or low risk of extinction.
– Many inshore rockfish species are at low abundance levels or are experiencing poor recruitment, and 89 areas, especially on the south coast, were closed to fishing at the time of writing.
– Stock assessment outlooks for 2004 classed 49% of managed salmon stocks in BC as stable, increasing, or well above target abundance, but about 13% of managed salmon stocks are in the category of greatest concern.
The report concludes, in relation to fish stocks: “Marine ecosystems are complex, and determining definitive causes for observed changes, whether positive or negative, is rarely straightforward. Whether the decline or low abundance of many of the species discussed in the indicators is related to overfishing, or to unfavourable ocean conditions perhaps related to global climate change is not known.”
In the area of ecosystems and biodiversity, the report notes that many of BC’s ecosystems are relatively intact, particularly in the northern and central coast. However, ecosystem loss is greatest in the South Coast where the human population is most concentrated. This area formerly contained some of the highest levels of biodiversity in the province, but it has been severely altered ecologically.
A warning note is struck that climate change will likely create additional pressure on ecosystems that are already stressed.
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[From WS September/October 2006]