Since 2016, Antarctic intermediate water has become saltier, denser and deeper, raising questions about ocean heat storage, circulation and climate change risks

King tides have inundated parts of both U.S. coasts. The tides are flooding streets and sending sea water into homes and businesses in beach communities in California, Florida and the Carolinas.

Traces of eDNA from 126 fish species have been sampled far north of their documented ranges in the Japan Pacific, offering clues to possible migration as ocean waters warm.

It’s summer in the United States, and temperatures are rising even more than usual, thanks to climate change. As the temperature rises in the air, so does the temperature in our ocean—with devastating...

The research team led by the University of Melbourne and the Indian Institute of Science has discovered that the Antarctic Intermediate Water (AAIW), a vast freshwater layer spanning the Southern Hemisphere’s oceans, has rapidly reversed its decadal trends in salinity, density, and depth. Published in Nature Climate Change, the study reveals that shrinking Antarctic sea ice since 2016 abruptly choked off seasonal meltwater delivery, causing the ocean layer to become warmer, saltier, denser, and deeper within less than a decade. The Antarctic “Freshwater Engine” and 2016 regime shift The Antarctic Intermediate Water plays a crucial role in regulating Earth’s climate by storing dissolved carbon, supplying oxygen to deep ecosystems, and driving global thermohaline circulation. The study highlights an unprecedented shift in this system’s multi-decadal behaviour: 1995–2015 Hydrological baseline For two decades, intense seasonal Antarctic summer sea ice melt recharged the AAIW with freshwater. The annual meltwater volume equalled triple the annual flow of the Amazon River (~19,800 cubic kilometres). Post-2016 abrupt reversal As Antarctic sea ice plummeted to historic lows in 2016, seasonal freshwater delivery dropped by a third. With reduced freshwater input, the AAIW experienced rapid salinification and densification. Geological precedent The last time the AAIW underwent a comparable...

YouTube video by The Secrets of the Universe

Adelaide University researchers have found that some estuarine fishes that live in habitats with highly variable temperatures can withstand the warmer ocean conditions expected to result from climate change. The study, published in Global Change Biology, shows estuarine fishes’ resilience to these extreme conditions is genetically determined. “Climatic extremes are increasing in frequency, intensity, and duration across Earth’s biomes as a consequence of anthropogenic climate change,” said project leader Professor Ivan Nagelkerken, from Adelaide University’s School of Biological Sciences. “In aquatic systems, climatic extremes can rapidly restructure communities, disrupt ecosystem functioning, and compromise ecosystem services, including fisheries productivity. “Our study examined the resilience of three economically important estuarine species, which we found to be ‘thermal generalists’ with a genetic ability to withstand extreme conditions.” The study, performed by Dr Angus Mitchell, focused on yellowfin bream, sand whiting and tarwhine due to the species’ important role in the fisheries industry. “Yellowfin bream and sand whiting are among the most commonly caught inshore species by recreational and commercial fishers on the east coast,” Dr Mitchell said. “They’re what people target to take home, so understanding whether they can cope with warming estuaries matters directly for the fisheries that coastal communities depend on.”...

An international rescue operation for the last 30 captive whales in Canada made headlines. Then five of them died.

Peru’s anchoveta have made up about a 10th of the entire global commercial fishing catch since 1970, more than any other fish. A combination of warming seas and decades-long overfishing spells disaste...

Computer models suggest that unrealistically cold oceans would be insufficient to stop Thwaites glacier retreating, although a neighbouring glacier might begin to grow

The world's coral reefs are in crisis, but a crafty solution could help.

YouTube video by Momocracy