Marine biology

Massive starfish die-off tied to warming seas

Sea stars shown dying off.
At left, thousands of sunflower sea stars swarm Croker Rock, British Columbia, on Oct. 9, 2013. At right, the same site, three weeks later, with the sea stars vanished. Photos: Neil McDaniel

The predatory sunflower sea star, whose limbs can stretch 4 feet across, is rapidly disappearing due to infectious disease outbreaks worsened by marine heat waves, a comprehensive new study found.

Why it matters: The sea star, Pycnopodia helianthoides, is a vital component in marine ecosystems. In its absence, scientists documented a large increase in many types of urchins and a subsequent decline in kelp populations, to the potential detriment of many other species. The study warns of the potential for a "trophic cascade" to occur, "causing urchin populations to explode and kelp to rapidly diminish."

Scientists find new evidence of life beneath Antarctic ice

The borehole showing the location where the drill broke through to Subglacial Lake Mercer.
The UV collar and borehole, showing the water of Subglacial Lake Mercer, from the SASA Project. Photo: Billy Collins, SALSA Science Team.

A research team drilling thousands of feet under the Antarctic Ice Sheet has found new evidence of microbial life there — life forms not known to exist elsewhere.

Why it matters: It's only the second subglacial lake in Antarctica to be explored, in an area as vast as twice the area of the continental U.S. That means scientists have to draw a lot of conclusions from drilling two holes — but it's the only way to learn about what kind of life exists in the mysterious world of subglacial lakes and rivers deep beneath the ice.

More stories loading.