Science

"The demand for basking shark fins, which can fetch prices in excess of $50,000 for a single large fin, is continuing to drive the exploitation, surreptitious and otherwise, of this highly threatened species," said Mahmood Shivji, who led the research and directs the Guy Harvey Research Institute at Nova Southeastern University in Florida. "This finding, along with our recent research documenting extremely low genetic diversity in basking sharks worldwide, raises urgent concerns about the longer-term health of this species."

The scientists, who also came from the Pew Institute for Ocean Science, Imperial College London and Britain's Durham University, said they learned that when Chinese fin traders used the term "Nuo Wei Tian Jiu," they were often referring to basking sharks.

-- Juliet Eilperin

Bad Buzz on Mosquito Repellers

As mosquito season approaches, a new analysis has some bad news for people who use electronic high-frequency mosquito repellers to keep those annoying, sometimes disease-carrying insects at bay: They do not work.

High-frequency mosquito repellers are designed to drive away female mosquitoes by emitting high-pitched sounds that are almost inaudible to the human ear.

To evaluate the devices, the Cochrane Collaboration, which systematically evaluates a wide variety of scientific claims, reviewed the evidence for their effectiveness.

The researchers found 10 field trials that had been carried out in different parts of the world and that involved various species of mosquitoes. None showed any evidence that the devices work.

"All 10 studies found that there was no difference in the number of mosquitoes found on bare body parts of the human participants," said Ahmadali Enayati of the Mazandaran University of Medical Sciences in Iran, who led the work.

The review did not evaluate other devices to fend off mosquitoes.

-- Rob Stein