Posts Tagged ‘sharks’
Using Magnets and Stink Bombs to Keep Sharks at Bay
The discovery earned Shark Defense $25,000 from the World Wildlife Fund’s annual International Smart Gear Competition, which rewards inventors who develop new methods to keep animals from getting tangled in commercial fishing lines. Shark Defense is now investigating ways to embed the metals in nets. And Stroud says the same metals, worn as an anklet, could act as a personal shark deterrent.
The company is also working on a chemical repellent, a slightly sweet-smelling combination of a dozen compounds that mimics the scent of rotting shark. Patrick Rice, the senior marine biologist at Shark Defense, has developed the repellent in several forms: as a pressurized can of aerosol spray that can create a 50-milliliter cloud and is popular with spear fishers, a pouch that bursts underwater to quickly clear an area, and a gel that can be injected into bait to keep sharks from getting hooked. The chemical repellent is less expensive than rare-earth magnets. Still, Rice says, “just like anything else, nothing’s 100 percent effective. If sharks are in a frenzied state, if they’re hungry enough, they’ll start eating.”
Adapted from Juliet Eilperin's book, .
Great White Sharks Text Their Whereabouts, For Science and Swimmer Safety
A research effort doubles as a shark-attack warning system
It’s not known how far great whites—whose worldwide numbers are estimated to be fewer than 3,500—migrate or if there’s a season when they spend more time near the coast, says Rory McAuley, a senior research scientist with Western Australia’s Department of Fisheries. McAuley hopes that the buoys, along with about 50 sensors on the ocean floor, will also reveal behavior. This information could help authorities better predict the monthly risk at beaches and restrict seasonal shipping routes to protect sharks from boats.
As a bonus, the work could give swimmers a heads-up when a great white is closing in. If a tagged shark swims within approximately a quarter-mile of a coastal buoy, the system sends a text to lifeguards on nearby beaches. Even swimming at top speed, it might take the dangerous fish a couple of minutes to reach shore, possibly enough time for the lifeguards to drop the phone and sunscreen and get folks out of the water.