With vomiting harbour porpoises becoming stranded in Patricia Bay, humpback whales colliding with boats off the north Island, dead whales found drifting near Tofino and poison-laden orca starving off Victoria, our coastal wonderland seems to be anything but for wildlife residents.
So much of what we do to the ocean remains hidden from sight. We flush our toilets into it, let the wind blow our garbage into it, dump our bilges into it, wash our streets into it. And despite receiving our filth for more than 150 years, the sea around us continues to reflect sunshine, sky and shorelines.
The ocean holds its secrets close.
Fortunately, we鈥檙e getting better 鈥� slightly better 鈥� every year at tracking what goes on in the watery depths. Complex high-tech advances and tried-and-true low-tech applications help us plumb more of Davy Jones鈥檚 locker each year. We use satellites, sea-floor fibre-optic arrays and next-generation genetic decoding, as well as the usual see-鈥檈m-and-note-鈥檈m census-taking to peek beneath the waves.
Every bit of information we gain helps us find ways to lessen the damage we do and to ground those strategies more securely in science.
For instance, researchers from the University of Washington in Seattle reported last year that the scarcity of chinook salmon in the area stresses resident orca more than the amount of boat traffic. The whales spend their time in these waters slowly starving while they hunt for the few remaining chinook, their preferred food.
A draft report released by provincial, federal and U.S. agencies at about the same time assesses the salmon fishery鈥檚 contribution to the whales鈥� declining health. Because commercial and recreational fishing remove only about 20 per cent of chinook salmon from the straits between the mainland and 91原创 Island, the report concludes that adjusting the Fraser River fishery would likely do little to improve the fish鈥檚 鈥� and the whales鈥� 鈥� fortunes.
However, other rivers in the northeastern 91原创 seem to still produce sufficient chinook for the orca. According to the Washington researchers, when the whales return here each spring, they鈥檙e well fed. It鈥檚 only while they鈥檙e here that they starve. They鈥檙e eating, and eating well, elsewhere. We just don鈥檛 know where. If we did, we could move to protect fish stocks from those rivers to help orca bulk up before they summered in Juan de Fuca and Haro straits.
And although salmon scarcity overrides other influences on resident-orca health, that doesn鈥檛 mean boat traffic is off the hook. Many studies show whales and other marine mammals change their behavior when boats pass nearby.
Last year, a team of scientists from Australia, Scotland and Victoria mapped underwater noise off B.C.鈥檚 coast. Using ship-traffic information and a computer model of how sound spreads through water, the map shows noise exceeding recommended levels in many critical orca habitats. Managers can use that information to set and adjust shipping-traffic guidelines. Industry can use it to develop technologies that dampen engine and propeller noise.
It seems the more we find out about what goes on under the waves, the more worrying the view is. However, despite the troubled waters, numbers of some key B.C. marine species are increasing. Whales, seals and sea lions had been hunted throughout the North 91原创 for centuries. Hunting was outlawed here and elsewhere decades ago, and now more minke, fin, grey, humpback and sperm whales, as well as Steller and California sea lions, are returning to B.C. waters.
It goes to show when we adjust our behaviour, improvements can occur. The more we know about how our ocean works, what its residents require and how we affect them, the better able we are to make ocean-wise choices.
