Killer Whales Believed Threatened By
Human Activity

Thursday, March 23, 2006
SEATTLE, WASHINGTON - Every year, thousands of tourists flock to Canada's west coast and Washington State's San Juan islands to see 10,000 pound killer whales doing graceful belly-flops, acrobatic back-dives, and forceful tail-lobs in their natural habitat.

The whale watching adventure has become so popular that the profits made from safari companies have become an integral part of the West Coast economy. However, our fascination with these powerful sea creatures, leading to their ever-increasing interactions with humans, may be setting the stage for their eventual extinction.

Orcas generally have in infant mortality rate of 50 percent and female orcas give birth once in every 3 to 5 years. Orca families also do not mate outside their lineage despite having close contact with other pods. Some scientists have seen a fluctuating decline of orca populations in the areas surrounding Vancouver Island, which may be related to human activity in the area.

Since orcas are so fragile, human interaction with these whales, and way of life, tremendously affect their living habits. Salmon populations, the major food source for orcas, are declining each year. Dams, constructed on rivers the Salmon traditionally swim long distances into to breed, are preventing the fish from reaching their spawning grounds.

Alexandra Morton, Director of the Raincoast Research Society, who has been studying whales since 1978, explains the effect of dwindling salmon runs.

"The majority of whales on the west coast completely depend on salmon, and many of the whale families also depend on salmon because they eat seals and sea lions that also eat salmon. Salmon are like the energy source for this whole area and by allowing the wild salmon to be killed off you're pulling the plug on the whole system," says the biologist.

"Killer whales, being at the top of the food chain, absolutely will not be able to survive the loss of the salmon and the other species around them. They need that whole food pyramid below them to survive."

Industrial pollution has also affected the orca's health and longevity and biologist like Morton are concerned.

"The tissue of these whales is showing very high levels of toxins, it's very serious, particularly for the whales that eat mammals because the higher up the food chain they are the more of theses toxins they're collecting. The whales that eat fish have less toxins."

As a result of depleting salmon stocks and increased pollution, the killer whale population in the area dropped by 20 percent over 5 years in the late 1990s, from 79 to 99 whales, according to Patti Goldman, the managing attorney with the Seattle office of Earth Justice.

"There have been some births with the offspring living past a year, so the numbers are slightly up, but it's still much lower than it should be," says Goldman.

Most at risk are the southern killer whale pods—those in the area around Seattle, Vancouver, and Vancouver Island—which have higher toxin levels in their systems. Whales further north, near Alaska, not only have fewer toxins, but also have healthier salmon stocks.

Some scientists believe that if these trends continue, the orca population around Vancouver Island will continue to decline.

In response to that threat, conservation groups filed a court action late in 2002 to overturn the U.S. National Marine Fisheries Service decision to not classify the whales as an endangered species—something Canada did as soon as scientists discovered the whale population had dropped.

The lawsuit succeeded.

"This means that any federal government action has to make sure that it will not jeopardize the continued existence and recovery of the orcas. And it's not just the government, people also have to avoid taking actions that will injure or kill individual orcas," says Goldman.

Source: The Epoch Times