Warming temperatures are wreaking havoc with ecosystems in the Arctic. Wild reindeer populations have halved in just two decades on land. In the sea, meanwhile, toxic algae blooms have invaded large swathes of territory and affected animals from fish to seals.
So warns the U.S.’s National Oceanic and Atmospheric Administration (NOAA) in its 2018 Arctic Report Card, which was complied by 81 scientists from 12 nations.
“Continued warming of the Arctic atmosphere and ocean are driving broad change in the environmental system in predicted and, also, unexpected ways,” the report says. “New and rapidly emerging threats are taking form and highlighting the level of uncertainty in the breadth of environmental change that is to come.”
Since 2014 air temperatures in the Arctic “have exceeded all previous records since 1900” when records first began to be kept. Between October 2017 and September 2018, a period the scientists studied, the average yearly temperature the northern region was 1.7 Celsius higher than the average between 1981 and 2010.
“The year 2018 was the second warmest year on record in the Arctic since 1900 (after 2016),” the researchers noted, adding that sea ice cover in the Arctic was at its second-lowest recoded extent.
Disconcertingly, changes in weather patterns are impacting local vegetation. Warming temperatures have caused more land to lose its permanent ice cover, which would on the surface seem to be beneficial for grazing animals.
However, local vegetation has been affected in ways that have decimated populations of wild reindeer, also known as caribou. Lichen, a staple food for reindeer in winter, is being outcompeted by taller vegetation like shrubs, which means many of the animals can’t find enough to eat during certain periods.
Warmer temperatures have also allowed insects and parasites to spread farther and wider. “Warmer climates just mean more bugs in the Arctic,” said Prof. Howard Epstein, an environmental scientist at the University of Virginia who worked on the Arctic Report Card. “It’s said that a nice day for people is a lousy day for caribou,” he elucidated. “If it’s warm and not very windy, the insects are oppressive and these animals spend so much energy either getting the insects off them or finding places where they can hide from insects.”
Overall, in just 20 years or so herds of wild reindeer across the Arctic tundra have declined by 56%. Until recently there were some 4.7 million reindeer in the area, but now there are only 2.1 million. Some local herds have shrunk by as much as 90% with no sign that they might be able to recover any time soon.
Meanwhile, algae blooms have been affecting marine creatures, large and small. “Considerable concentrations of algal toxins have been found in the tissues of Arctic clams, seals, walrus, and whales and other marine organisms,” the report says.
“The long-term warming trend may be taking a toll on some of the Arctic’s most majestic animals,” Epstein warns.
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