‘Damaging the Antarctic damages us all’ – scientists warn of the potential impacts of coastal freshening
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New research by the University of Plymouth and the British Antarctic Survey focused on the giant amphipod species Paraceradocus miersi, found in abundance in Antarctic waters and relatives of the sandhoppers on temperate beaches
view moreCredit: John Spicer/University of Plymouth
Many of the Antarctic’s smallest inhabitants have evolved over millions of years so their body fluids are similar in chemical composition to that of sea water. However, a combination of melting glaciers, increased rain and extreme weather events means that waters in some of the remotest parts of the planet are increasingly being exposed to a reduction in salt levels.
Scientists refer to this phenomenon as freshening, and a new study has highlighted the impact this could have on species living in the shallow coastal waters off Antarctica. It has led researchers to warn that continued coastal freshening may pose a significant threat to many marine invertebrates living in the region, but that it could also change the nature of the global ocean.
The research was conducted by scientists at the University of Plymouth and the British Antarctic Survey (BAS), and builds on previous work by the organisations to assess the impact of changing ocean conditions on some of the planet’s smallest, but most important, inhabitants.
Professor John Spicer, Professor of Marine Zoology at the University of Plymouth and the study’s lead author, has spent almost 40 years examining the effect of climate change on marine organisms.
He said: “I was working at the Rothera Research Station on the Antarctic peninsula in 2017 when there was an extreme freshening event. I was interested in the effect this would have on one of the region’s largest amphipods, and we found that even if the water is diluted fractionally, the amphipods lose their salts, gain water and their gills are damaged.
“This is important for the whole planet as while Antarctica and its wildlife are wonderful, they are also essential to a functioning environment. Damaging the Antarctic damages us all, and if there is freshening it will not have to be very strong before the health of many invertebrate species will be severely impacted.”
Published in the Marine Environmental Research journal, the new research focused on the giant amphipod species Paraceradocus miersi, found in abundance in Antarctic waters and relatives of the sandhoppers on temperate beaches.
Using creatures collected from Ryder Bay on the Antarctic Peninsula, researchers assessed how their body fluids and internal organs responded when exposed to a simulated freshening experiment. They found that when exposed to reduction in salt levels within the water, the species was still able to regulate some of the key chemicals – including calcium – which are critical to its bodily functions.
However, its overall regulation of the ions that make up the full concentration of sea water is impaired meaning the amphipods lose their salts, gain water and their gills are damaged. This, the researchers say, could have led to significant deaths among shallow-dwelling individuals during the 2017 freshening event and other similar events before and after it.
Dr Simon Morley, an Ecophysiologist at the British Antarctic Survey and a study co-author, added: “As climate change continues, environments will change beyond the conditions that animals living there can cope with. In the seas around Antarctica, the biggest signal of climate change is the melting of ice and this is adding large quantities of freshwater into the oceans. This lowering of salinity could have dramatic impacts, reshaping the communities on the sea floor. Our study provides critical evidence of what could happen to different species in the future.”
‘Damaging the Antarctic damages us all’ [VIDEO]
Professor John Spicer, Professor of Marine Zoology at the University of Plymouth and the lead author of the new study published in Marine Environmental Research, has spent almost 40 years examining the effect of climate change on marine organisms
Journal
Marine Environmental Research
Method of Research
Experimental study
Subject of Research
Animals
Article Title
The giant Antarctic amphipod Paraceradocus miersi will not fare well if freshening continues in the Southern Ocean
Article Publication Date
24-Aug-2026
Hotter tropical pool temporarily slows Antarctic ice loss
Chinese Academy of Sciences Headquarters
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Totten Ice Shelf, East Antarctica, photographed in late 2019.
view moreCredit: Image by Prof. Yoshihiro Nakayama
A warming pool of tropical ocean acted like a “regulator,” dialing up snowstorms over East Antarctica and contributing to a brief net ice-sheet mass gain of 695 billion tons, according to a new study published in Nature on August 19.
The study revealed that sustained warming of the tropical warm pool during 2021–23 triggered a Rossby wave train propagating toward Antarctica, formed a north–south dipole circulation over East Antarctica, reorganized moisture transport, and enhanced regional snowfall, thereby temporarily slowing Antarctic ice-sheet mass loss.
The Antarctic Ice Sheet is one of the major sources of uncertainty in future global sea-level rise. Over the past two decades, it has experienced sustained mass loss at a rate of approximately 140.5 billion tons per year. However, its mass increased by about 695 billion tons during 2021–23, marking the largest mass-gain event recorded by the GRACE satellites.
To identify the cause, a research team led by the Institute of Oceanology of the Chinese Academy of Sciences (IOCAS) combined gravity-satellite observations, ice-core snow-accumulation records, and atmospheric circulation model simulations to investigate the atmospheric circulation mechanisms and moisture sources underlying this mass-gain event.
The results showed that, during 2021–23, sustained warming occurred in the tropical warm pool located in the region where the tropical western Pacific and eastern Indian Ocean meet. This warming triggered a Rossby wave train toward high southern latitudes. Eddy-mean flow feedbacks amplified and sustained the resulting circulation, establishing a north–south dipole with low- and high-pressure anomalies south of Australia and along the East Antarctic coast, respectively. The dipole redirected moisture and enhanced atmospheric-river transport from the midlatitude Indian Ocean to East Antarctica.
Water-vapor tracking simulations showed that, under the influence of the dipole circulation, moist air from the midlatitude Indian Ocean was transported to East Antarctica, allowing more atmospheric rivers to reach the region. This resulted in persistent heavy snowfall over the Queen Mary Land–Wilkes Land region and increased ice-sheet mass.
Atmospheric circulation model experiments confirmed that warming of the tropical warm pool was the direct driver of the circulation and snowfall responses. The increase in regional snowfall attributable to anthropogenic forcing was equivalent to only 9% of the observed snowfall anomaly, indicating that atmospheric moistening caused by global warming was not the primary cause of this event.
Further observations and simulations showed that similar sustained tropical warm-pool warming events occur approximately once every decade. The tropical warm pool therefore acts like a remote “regulator,” influencing multiyear variations in snowfall and ice mass over East Antarctica.
However, this temporary slowdown cannot reverse the long-term trend of Antarctic ice-sheet mass loss. The West Antarctic Ice Sheet continues to lose ice, while some outlet glaciers in East Antarctica are also threatened by basal melting of ice shelves and accelerated ice flow caused by warm ocean waters.
This study not only reveals the mechanism by which sustained tropical warm-pool warming drove a temporary increase in Antarctic ice-sheet mass, but also shows that the north–south dipole circulation over East Antarctica plays a key role in connecting the tropics with ice-sheet mass changes.
“We found a previously underrecognized ‘tropical warm pool–East Antarctic Ice Sheet’ teleconnection pathway,” said WANG Yunhe from IOCAS, first author of the study. “Our research provides a theoretical basis for understanding Antarctic ice-sheet mass changes and conducting future research on the East Antarctic climate.”
Teleconnection mechanism linking tropical warm-pool warming to temporary Antarctic ice-sheet mass gain.
Credit
Image by IOCAS
Journal
Nature
Article Title
Multiyear tropical warm pool warming drives slowdown in Antarctic mass loss
Article Publication Date
19-Aug-2026
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