Earlier this week, several New York state beaches were closed due to shark sightings. Fox News’ Rick Leventhal, speaking as part of Bill Hemmer’s “America’s Newsroom” show, reported on this story, claiming that “some onlookers ID’ed them as thresher sharks, they’re estimated to be about 18 feet long”. A half-eaten seal also washed up on shore nearby.
To his credit, Mr. Leventhal attempted to play down fears about these animals, saying that “Let’s not forget that sharks live in the ocean…as long as there’s food, they’re likely to keep hanging around”. However, I was immediately skeptical of the claim that a group of 18 foot long thresher sharks were swimming slowly just a few yards offshore. A cursory review of the known biology and ecology of thresher sharks will explain my skepticism.
Modern shark researchers have access to a variety of high-tech tools. Acoustic tags with noises specific to each individual shark signal a receiver (or network of receivers) every time the shark passes nearby. Some tags have three-dimensional accelerometers, allowing researchers to study the small scale movement patterns and behaviors of sharks. Others, which are placed in the stomach, measure pH before, during, and after digestion. The most advanced technology on the market, however, is undoubtedly the satellite tag.
The shark blog-o-sphere has been busy lately. Here are some of the headlines from the world of shark science and conservation.
Chuck from Ya Like Dags has a fantastic post explaining the ecology of fear and how it relates to sharks. As it turns out, predators can have a major impact on an ecosystem just by being there- prey change their behavior in ecologically significant ways because they want to avoid being eaten. If you’re looking for scientific reasons why sharks are important to the ocean or if you’re just looking for a cool ecology story, check it out!