Earthweek: a diary of the planet

For the week ending Friday, Feb. 3.

Oceanic success

The decline in shark and ray species in the northwestern Atlantic appears to have been reversed, thanks to improved fisheries management and conservation. Shark and ray populations have crashed by as much as 71% in the past 50 years, with about one-third threatened with extinction. But writing in PNAS, Nathan Pacoureau of Simon Fraser University credits the implementation of the 1993 U.S. Fishery Management Plan for Sharks of the Atlantic Ocean for the turnaround. That act mandates catch reports and bans the catching of some species.

Skeeter defense

A new device designed for U.S. military personnel living in and around tents can provide hands-free and automatic protection against bites from disease-carrying mosquitos for extended periods of time. It has the potential for use in backyards and camping sites. The controlled-release device is made up of small plastic tubes that are about 1 inch long. They drip the insecticide transfluthrin, which is said to be safe for use around humans and wildlife at the recommended doses, across the tent’s entrances.

Titicaca drop

Bolivian officials say a prolonged drought has caused the water levels of Lake Titicaca, the world’s highest navigable lake, which straddles the border of Bolivia and Peru, to plunge to historic low levels. Bolivia’s National Service of Meteorology and Hydrology forecaster Ana Luz Mendoza warned that the drop directly affects the aquatic fauna, birds and human populations around this lake.

Brutal drought

One of Argentina’s worst droughts in 60 years and accompanying record heat have left many rivers and lakes littered with dead fish, and its staple crops ravaged. The climate disaster has been fueled by the third consecutive year of La Niña cooling across the tropical Pacific, according to meteorologists. But a shift from La Niña to a fresh El Niño this year promises to break the drought and deadly heat during the next few months.

Cyclone aftermath

Late reports from Madagascar say mudslides and flooding from Cyclone Cheneso’s outer bands killed at least 30 people while washing out bridges and swamping homes the previous week.

Seaweed farms

An Australian study finds that expanding seaweed farming around the world could help feed the planet’s growing human population and livestock while also being a sustainable source of fuel. “Seaweed has great commercial and environmental potential as a nutritious food and a building block for commercial products, including animal feed, plastics, fibers, diesel and ethanol,” said researcher Scott Spillias from the University of Queensland. Writing in Nature Sustainability, Spillias says millions of acres of ocean territory have already been identified around the world where at least 22 commercially viable species of seaweed could be harvested.