The study, published in the latest Royal Society Biology Letters, suggests that although killer whales may consume a variety of fish species and mammals, many of them are highly dependent on a single species of salmon. Some killer whale populations favor king salmon so much that the whales will actually die when numbers of this largest member of the salmon family drop. "Nutritional stress" probably leads to killer whale deaths because it can make the whales "susceptible to other factors leading to mortality, such as disease and parasitism," and possibly also more vulnerable to the "immuno-suppressive effects of PCBs" and other ocean pollutants, said lead author, John Ford, to the Discovery News. Scientists have determined that from 1974 to the mid 1990's, killer whale populations steadily grew in number at an increase of nearly 2.6 percent per year. That pattern ended in the mid 1990's, when both analyzed populations of killer whales entered a period of an obvious decline, dropping by up to 17 percent in 2001. Ford and his team instead believe some killer whale populations are dependent on Chinook Salmon as their primary year-round food resource, even though these predators have the ablility to eat all different species of fish without having issues. Even though some killer whales only prey on king salmon, Fisheries and Oceans Canada calls for strengthening killer whale populations by ensuring enough food for this animal to survive.
This article was intersesting to me because of many reasons. One reason being how the Killer whale completey relies on King Salmon, even though it can eat all different types of fish species. Also I think we need to save these beautiful creatures because they are slowly drifting away from having an abundant population. I think by providing systems that help King Salmon produce in greater amounts will help the whales in a way that most systems would not. By allowing these killer whales to grow in a greater amount will cause only good things to happen within this organization. We must do all we can to save this type of species and focus on whats really important in our world today. We must do all we can to save any type of any animal species no matter what the circumstances are.
Allie Thorndike
I was very surprised to see how the population of Killer Whales has tremendously gone down. I have always seen these creatures as wonders of the ocean. I was also surprised that such large creatures would only have a craving for the King Salmon. The Pacific and Canadian major waterways is where these creatures would be found. The loss of these whales would not only effect their population, but the tourist economy, for many tourists come to these coasts to whale watch. I would like to learn more about why the Killer Whales are being selective of the fish, and if tests or tagging of fish can help prevent the spread of PCBs. We, as a society, can also use methods to increase the Salmon population by limiting the amounts that can be caught during the Salmon's season. This would greatly benefit the Killer Whale population and the ocean's food cycle.
ReplyDeleteI think this article is very interesting because killer whales are a big predator in the ocean and I never realized that they lived in the same types of waters as salmon did. I always thought salmon lived in streams where they were mainly hunted by bears. One concern I have about this article is how the Fish and Oceans Canada group would be able to control the salmon population and keep it stable enough to provide for a whole population of whales. It seems to me like it would be hard to regulate salmon birth rates unless they put a limit on salmon-catching season and even then there is no way for them to regulate how often other species feed on these fish.
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