Gulf turtle evacuees could get lost at sea

Turtles are being relocated from the US Gulf coast to save them from the Deepwater Horizon oil spill – but this may scramble their navigating skills, marine biologists warn. As a result, the animals could lose their way to their nursery grounds.

The turtles – mostly threatened loggerheads, as well some endangered Kemp's ridley, green and leatherback turtles – use the Earth's magnetic field to navigate often hazardous migration routes. They travel from their birthing beaches of Florida and Alabama to the open sea and then on to their nursery grounds around the Azores and Canary Islands, where they live for years before returning to their home beaches to nest as adults.

The first batch of evacuated sea turtles, rescued as eggs from the oil-drenched Florida Panhandle and Alabama beaches, to hatch at Kennedy Space Center in Florida were released into the Atlantic Ocean on Saturday. The evacuation was part of a campaign spearheaded by the US Fish and Wildlife Service to move all Gulf coast turtles' eggs – there are at least 50,000 – from their native breeding grounds to the unaffected Atlantic shores of Florida.

The eggs are being evacuated 50 to 53 days after laying, in the final stages of their 60-day incubation. Immediately after hatching they will be released along Florida's Atlantic beaches. But some researchers are warning that releasing Gulf coast turtles straight onto the sand on the other side of Florida could interfere with their navigational skills.

Air pollution

Air pollution doesn't just make it hard to breathe – it may also increase the risk that people will take their own lives.

A new study in seven cities across South Korea has uncovered a clear association between suicide and spikes of particulate pollution. Meanwhile, researchers who in the 1990s linked air pollution to asthma in a large group of Taiwanese children have now found that those with the condition were subsequently more likely to have killed themselves.

Suicide is a big problem for South Korea, where the rate per 100,000 people rose from 14 in 1996 to 23 in 2006 – the largest increase in the developed world.
Soot and suicide

To examine the role of pollution, researchers led by Chang Soo Kim of Yonsei University in Seoul linked records of more than 4000 suicides to measurements of PM10 – airborne particles with a diameter of 10 micrometres or less, which include the soot from vehicle exhausts.

Kim's team found that suicides were more common in the two days following a spike in pollution. They considered PM10 measurements on a scale from the highest and lowest levels recorded, calculating that people were 9 per cent more likely to kill themselves following a spike in pollution rising across the middle 50 per cent of recorded values. For people with cardiovascular disease, which has already been linked with particulate pollution, the increase was almost 19 per cent.

South Korea's cities, like many in Asia, are badly blighted by air pollution, and it is unclear whether the effect would be so dramatic in cities that have tighter pollution controls. "Further investigations of low-level exposure to particular matter are needed," says Kim.

Grow-your-own approach to wiring 3D chips

When the island of Manhattan became too crowded, architects responded by building skyscrapers. The increasing density of components on "flat" computer chips is encouraging similar ideas, building upwards to create three-dimensional chips. But moving from flat interconnecting wires to 3D ones to link up different "storeys" has proved a tricky business – until now.

Instead of soldering prefabricated wires in place, as is traditionally done to connect two parts of a chip, Min-Feng Yu and Jie Hu at the University of Illinois at Urbana-Champaign have developed a technique to grow tiny 3D wires in situ which are tailor-made for their location.

Yu and Hu's technique is a modified form of electroplating, in which an electric current is used to coat a conductive surface with a thin layer of metal, deposited from a liquid electrolyte. Such a technique theoretically offers a way to directly "write" metal wires onto a surface.

Super goby helps salvage ocean dead zone

A resilient fish is thriving in an inhospitable, jellyfish-infested region off Africa's south-west coast. And crucially it is helping to keep the local ecosystem going, and to preserve an important fishery.

The Benguela ecosystem lies off the coast of Namibia. It exists in waters only 120 metres deep that used to be a rich sardine fishery, but in the 1960s the sardine population crashed because of overfishing and environmental factors, and the region was invaded by algal blooms and swarms of jellyfish.

The algae have used up almost all the oxygen in the water, leaving the bottom half with oxygen levels below 10 per cent, far too little for most sea creatures. At about 80 per cent, levels are almost normal in the upper waters – but those regions are thick with jellyfish and algae, and therefore unwelcoming to most other life.

What's more, when the algae die they sink to the bottom and decay, releasing large quantities of the poisonous gas hydrogen sulphide. Nevertheless, local fish called bearded gobies have flourished in Benguela. Until now, nobody has understood how they survive it.