Ice in Bering Sea Declines to Lowest Level in 5,500 Years

 Ice breaks up early on the Kuskokwim River beside the Bering
Sea and near the climate change-affected Yupik Eskimo village of
Quinhagak on the Yukon Delta in Alaska, April 12, 2019. (AFP Photo)
Ice breaks up early on the Kuskokwim River beside the Bering Sea and near the climate change-affected Yupik Eskimo village of Quinhagak on the Yukon Delta in Alaska, April 12, 2019. (AFP Photo)
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Ice in Bering Sea Declines to Lowest Level in 5,500 Years

 Ice breaks up early on the Kuskokwim River beside the Bering
Sea and near the climate change-affected Yupik Eskimo village of
Quinhagak on the Yukon Delta in Alaska, April 12, 2019. (AFP Photo)
Ice breaks up early on the Kuskokwim River beside the Bering Sea and near the climate change-affected Yupik Eskimo village of Quinhagak on the Yukon Delta in Alaska, April 12, 2019. (AFP Photo)

Winter ice in the Bering Sea, in the northern Pacific Ocean between Alaska and Russia, is at its lowest level in the past 5,500 years.

Researchers analyzed vegetation that accumulated on the uninhabited island of Saint Matthew over the last five millennia.

According to AFP, they looked at variations in peat layers of oxygen atoms called isotopes 16 and 18, whose proportions over time correlate with atmospheric and oceanic changes and precipitation.

The 1.45-meter peat core, taken from Saint Matthew in 2012, represented 5,500 years of accumulation.

"It's a small island in the middle of the Bering Sea, and it's essentially been recording what's happening in the ocean and atmosphere around it," said Miriam Jones, the researcher who conducted the study at the University of Alaska and then at the US Geological Survey.

The ice in the Arctic and Bering Seas melts in summer and freezes anew in winter, but satellite observations only date back to 1979. The advantage of the new analysis, published in the journal Science Advances, is that it goes back much further in time.

For the Arctic, the reduction of winter ice in recent decades is clear and rapid, in parallel with global warming and the increasing concentration of carbon dioxide in the atmosphere. But the Bering Sea in recent decades has seemed stable, the authors of the study say, with the exception of 2018 and 2019, when a strong reduction was observed. In this study, researchers tried to establish whether the current levels are an anomaly or a trend.

"What we've seen most recently is unprecedented in the last 5,500 years," writes Matthew Wooller, director of the Alaska Stable Isotope Facility, who participated in the analysis.

At this rate, conditions are now favorable for a completely ice-free Bering Sea, the authors conclude, highlighting an effect of consequences on the ecosystem.



Researchers Document Huge Drop in African Elephants in a Half Century

 Elephants walk at the Amboseli National Park in Kajiado County, Kenya, April 4, 2024. REUTERS/Monicah Mwangi/File Photo
Elephants walk at the Amboseli National Park in Kajiado County, Kenya, April 4, 2024. REUTERS/Monicah Mwangi/File Photo
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Researchers Document Huge Drop in African Elephants in a Half Century

 Elephants walk at the Amboseli National Park in Kajiado County, Kenya, April 4, 2024. REUTERS/Monicah Mwangi/File Photo
Elephants walk at the Amboseli National Park in Kajiado County, Kenya, April 4, 2024. REUTERS/Monicah Mwangi/File Photo

African elephants are Earth's largest land animals, remarkable mammals that are very intelligent and highly social. They also are in peril. Fresh evidence of this comes in a study that documents alarming population declines at numerous sites across the continent over about a half century.

Researchers unveiled on Monday what they called the most comprehensive assessment of the status of the two African elephant species - the savanna elephant and forest elephant - using data on population surveys conducted at 475 sites in 37 countries from 1964 through 2016.

The savanna elephant populations fell by about 70% on average at the surveyed sites and the forest elephant populations dropped by about 90% on average at the surveyed sites, with poaching and habitat loss the main drivers. All told, there was a 77% population decrease on average at the various surveyed sites, spanning both species, Reuters reported.

Elephants vanished at some sites while their populations increased in other places thanks to conservation efforts.

"A lot of the lost populations won't come back, and many low-density populations face continued pressures. We likely will lose more populations going forward," said George Wittemyer, a Colorado State University professor of wildlife conservation and chair of the scientific board of the conservation group Save the Elephants, who helped lead the study published in the journal Proceedings of the National Academy of Sciences.

Poaching typically involves people killing elephants for their tusks, which are sold illegally on an international black market driven mostly by ivory demand in China and other parts of Asia. Agricultural expansion is the top factor in habitat loss.

The forest elephant population is estimated to be about a third that of savanna elephants. Poaching has affected forest elephants disproportionately and has ravaged populations of both species in northern and eastern Africa.

"We have lost a number of elephant populations across many countries, but the northern Sahel region of Africa - for example in Mali, Chad and Nigeria - has been particularly hard hit. High pressure and limited protection have culminated in populations being extirpated," Wittemyer said.

But in southern Africa, elephant populations rose at 42% of the surveyed sites.

"We have seen real success in a number of places across Africa, but particularly in southern Africa, with strong growth in populations in Botswana, Zimbabwe and Namibia. For populations showing positive trends, we have had active stewardship and management by the governments or outside groups that have taken on a management role," Wittemyer said.

The study did not track a continent-wide population tally because the various surveys employed different methodologies over different time frames to estimate local elephant population density, making a unified head count impossible. Instead, it assessed population trends at each of the surveyed sites.

A population estimate by conservationists conducted separately from this study put the two species combined at between 415,000 and 540,000 elephants as of 2016, the last year of the study period. It remains the most recent comprehensive continent-wide estimate.

"The loss of large mammals is a significant ecological issue for Africa and the planet," said conservation ecologist and study co-author Dave Balfour, a research associate in the Centre for African Conservation Ecology at Nelson Mandela University in South Africa.

The world's third extant elephant species, the slightly smaller Asian elephant, faces its own population crisis, with similar factors at play as in Africa.

Of African elephants, Wittemyer said, "While the trends are not good, it is important to recognize the successes we have had and continue to have. Learning how and where we can be successful in conserving elephants is as important as recognizing the severity of the decline they have experienced."

Wittemyer added of these elephants: "Not only one of the most sentient and intelligent species we share the planet with, but also an incredibly important part of ecosystems in Africa that structures the balance between forest and grasslands, serves as a critical disperser of seeds, and is a species on which a multitude of other species depend on for survival."