A Canadian zoologist, who studied the effects of boat traffic and exhaust on orcas for two and a half years, found carbon monoxide levels in the air of their natural habitats were five times greater than those found near Los Angeles freeways. Cara Lachmuth studied the southern resident killer whale population off the coast of British Columbia, where there are only about 87 orcas left. (Source: Marine Pollution Bulletin [pdf])
Lachmuth was surprised by the high levels of carbon monoxide found. She explained, saying, “when you’re out on the water there’s an inversion because the ocean is so cold and in the summer the air is a lot warmer — the CO is sticking right at that interface and it’s not moving vertically at all.”
In the Victoria and Vancouver area, whales are followed by an average of 20 boats for 12 hours a day during the summer. Boats used for recreational purposes might actually be contributing to the problem more than commercial boats, as they tend not to keep the minimum safe distance of 100 meters from the whales when they are trying to see them.
“If they’re inhaling these gases, it’s giving them immune problems and all kinds of other health problems that might be pushing them over the edge,” said Lachmuth.
Orcas in the area between Vancouver and Seattle are at risk from a variety of factors, including industrial waste and noise pollution. One major catastrophe such as an infectious disease or abrupt change in water temperature could sicken the population to the point they might not ever recover.
In her study, Lachmuth suggests limiting the number of vessels allowed within range of the whales, as well as limiting the amount of time vessels can spend in the area. This would cut down on both air and sound pollution that the whales are exposed to. This way the remaining orcas would have a chance to breathe some unpolluted air and not be so stressed by the incessant human activity.
If the orca population collapses, there won’t be any tour income generated any longer, so the current ways seem both short-sighted and even increasing the chance of a disastrous end for both the orcas, and the local tourism. Besides new legislation, another option for less impact on the orcas might be the use of electric boats. Such a change might prove too expensive in the short-term, however.
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