Stories tagged marine

Aug
10
2007

A shark, doing it's best: Mostly he just wants to be left alone.    (photo by Mshai on flickr.com)
A shark, doing it's best: Mostly he just wants to be left alone. (photo by Mshai on flickr.com)
Scientists in New South Wales and Florida are testing a new method of measuring the biting force of a great white shark using computer models.

Attempts have been made to measure sharks’ biting force underwater, in captivity and in the wild, although these are known to provide inadequate results. Sharks will generally do weak a “test bite” before applying the full force of their jaws, and these test bites are generally all that’s measured.

In this new experiment, researchers are dissecting a 2.4-meter long great white shark, in part to make an extremely accurate computer model of its anatomy, and in part to drive home the point that the animal should have just allowed them to measure its bite while it was alive. Advanced computing methods, originally developed for “calculating stresses in structures such as bridges,” will then be applied to the model, and should provide a much more accurate range of the shark’s biting force.

This process contrasts sharply with my own, I believe, much more elegant test of shark biting power. There are several simple steps involved in my method: Step 1 – gather a variety of small to medium sized objects. Step 2 - Rate the hardness of these objects, not on an objectively quantified scale, but relatively (for example: The kitten is harder than the pillow, but not as hard as the dictionary). Step 3 - Take these objects to your nearest shark. Get the shark to bite the objects (this can be difficult, but the right combination of chum and verbal abuse should do the trick). You will then have a simple and easy to understand scale of shark biting strength (for example: the shark could crush the pillow, the kitten, the dictionary, and the cookie jar, but not the lawn mower engine). If you still feel, at this point, that you need a measurement that uses more universally accepted units, you can then crush similar objects by yourself, far away from the shark, using free weights, or forty-pound bags of dog food. These can then be easily converted into newtons, or pounds per square inch, or whatever your physics teacher requires.

If the computer model method proves to give reasonably accurate results, I suppose it will then be up to individual researchers to choose that method or mine. It will just depend on whether someone doesn’t want to get their hands dirty, or if they care about style and integrity.

Mar
18
2005

More than 100 dead jumbo squid have washed up on the California coast since Sunday. Scientists haven't yet figured out why.

Humboldt squid normally live and hunt 3000 feet below the ocean's surface. This year, they seem to be swimming north from Mexico, following food sources that are bringing them closer to the surface and the shore.

Some scientists think that overfishing in Mexico may be reducing the amount of food available for the squid, forcing them to migrate into Southern California. (The squid may be confused by sand churned up by tides.)

Other scientists are studying the contents of the squids' stomachs, trying to determine if they're being poisoned somehow. (Large numbers of dead squid washed up on the shore in the same area in January, about a week after an oil spill from an undetermined source coated seabirds off the California coast.)

Research continues...