Great white sharks, the world’s largest predatory fish, eat three to four times more food than previously thought, an Australian study shows.

U.S. research from the 1980s estimated a 30-kilogram, or 66-pound meal of mammal blubber could sustain a one-ton shark for more than six weeks.

That perpetuated assumptions that large sharks could survive long periods without eating.

However, a University of Tasmania-led study published this week in Scientific Reports on the nature.com website found that 30 kilos was only enough for 12-15 days.

Researchers tagged a dozen great white sharks at Neptune Islands off South Australia and calculated their metabolic rate derived from swimming speeds.

They worked out how much energy the sharks burned and how much food they required.

Senior research scientist Jayson Semmens, lead author on the study, said the amount of energy required by great white sharks was equivalent to eating a seal pup every three days.

Sharks are most likely to attack surfers and other unsuspecting swimmers in shallow water, on Sundays, during new moons and especially in August, according to a study released Thursday just in time for summer.

Young surfers in black and white bathing suits are most vulnerable toshark attacks or bites, the University of Florida study found.

It based its conclusions on observations and statistics gathered over a 50-year period in Florida’s Volusia County, known as the “shark attack capital of the world.”

“Human, shark and environmental factors combine to create a perfect storm of favorable conditions in Volusia County for attacks, particularly near Ponce Inlet between Daytona Beach and New Smyrna Beach,” said George Burgess, director of the International Shark Attack File at the University of Florida.

We’re gonna need a bigger wind turbine. Or maybe not. German researchers are using shark skin to make windmills spin more efficiently, and generate more electricity. Not real shark skin, thankfully. This is shark-line skin that can be painted onto wind turbines, airplanes and ships to reduce flow resistance, or drag. Does this make your “Jaws” drop?
This type of biomimicry has already been tried with cars, to improve mileage, as Michael reported last year. The latest version comes from Fraunhofer-Gesellschaft in Germany, dubbed as the leading organization for applied research in Europe.
Shark skin was the inspiration because fast-swimming sharks have evolutionary scales that allow them to move quickly through the water and nab their prey. Swimmers and surfers, take note.
The shark paint was developed by Yvonne Wilke, Volkmar Stenzel and Manfred Peschka of the Fraunhofer Institute.
They say the paint system can lower costs, and as a result, carbon dioxide emissions. The recipe for the aerodynamic skin involves nanoparticles, to allow the paint to withstand ultraviolet radiation, temperature change and mechanical loads, according to information from the institute.
The paint lasts for about five years, at which time it has to be removed and reapplied. The paint is applied with a stencil (according to Stenzel), to give it a shark-skin structure.
For wind turbines, and commercial wind-energy parks, the paint could reduce air resistance, improve efficiency and result in greater energy generation, the researchers say. They estimate the paint could save almost 4.5 million tons of fuel a year if applied to every airplane in the world. Now that would be quite a contract.
For a large container ship, the paint could reportedly reduce wall friction by more than 5 percent a year, saving 2,000 tons of fuel annually.
The next task for the Germans: To develop shark skin paint that resists algae or mussels that accumulate on ship hulls.