Ocean Robot Goes Where No Robot Has Gone Before
An autonomous seafaring drone has made the first robotic crossing of Drake Passage, a turbulent stretch of the Southern Ocean that is key to the global climate but that is often too dangerous and expensive for oceanographers to study.
The passage lies between Antarctica and South America and is part of the Antarctic Circumpolar Current (ACC), which transports heat and carbon throughout the region. “The global connections are strong; the ACC provides a source for the overturning circulation of all three ocean basins, with important implications for future modifications of the climate system with changing surface temperatures and wind speeds,” wrote University of Washington researchers in a paper published in Oceanography, the magazine of the Oceanography Society.
In December, the scientists dispatched a wave-and-solar-powered robot the size of surfboard to Drake Passage on a mission to collect data on the mixing of heat energy in the top few hundred feet of the ocean, an area that satellites can’t penetrate. Called a Wave Glider and made by Liquid Robotics, a Silicon Valley subsidiary of Boeing, the robot was equipped with sensors to measure air pressure, temperature, wind and salinity.
“The Southern Ocean, and the Drake Passage in particular, are key locations that are historically undersampled,” Jim Thomson, a University of Washington oceanographer and the paper’s lead author, said in a statement.
The Wave Glider zig-zagged across Drake Passage for three months but didn’t quite complete its mission to reach South America – the robot’s solar-power batteries could not recharge due to the weak late-summer Antarctica sun – and researchers picked up the robot near Argentina.
But the scientists called the mission a resounding success.
“The mission just completed would have cost many millions of dollars to complete with a ship,” said Thomson. “An autonomous approach allowed us to collect data that has never – and would never have – been collected in this remote region.”
Rockfish Rocket Back, Thanks to Marine Reserves
More evidence that marine protected areas work: A new study finds that depleted rockfish fisheries off California are recovering after being made off-limits to fishing.
By the late 1990s, cowcod, bocaccio and other species of rockfish had been overfished to the point of collapse in the waters off Southern California. In response, the National Oceanic and Atmospheric Administration (NOAA) in 2001 created two large marine protected areas southwest of Los Angeles that prohibited fishing below 110 feet (30 meters) – where rockfish live – in a 4,300-square-mile area (11,000 square kilometers).
Sixteen years later, the fish have recovered to the point where they are dispersing larvae into the ocean surrounding the marine reserves, according to research published in the journal Royal Society Open Science by scientists from NOAA Fisheries’ Southwest Fisheries Science Center, the University of San Diego and the University of Massachusetts, Amherst.
“This is the first research we know of to demonstrate that marine protected areas are producing high abundances of fish larvae that can seed surrounding areas,” Andrew Thompson, a NOAA research scientist, said in a statement. “That’s good for fisheries because it can build populations beyond the protected waters too.”
Arctic Sea Ice Extent Is Eighth Lowest
This year’s lowest extent of Arctic sea ice was 1.8 million square miles (4.6 million square kilometers). Still, that’s 610,000 square miles (1.6 million square kilometers) less than the average minimum extent between 1981 and 2010.
In recent years, rapidly warming temperatures in the Arctic have dramatically reduced sea ice that polar bears, walruses and other species depend on for food and habitat. But relatively mild temperatures in 2017 limited the loss this year, according to NASA.