In Alaska, 7 billion fewer crustaceans


In Alaska, 7 billion fewer crustaceans

In Alaska a real demographic decline in the crustacean population has been studied, and it would be at least 7 billion fewer crustaceans. In 2021 there were 1 billion spider crabs compared to about 8 billion in 2018. The dramatic discovery was made by the Alaska Department of Fisheries and Game.

Board of Fisheries and the North Pacific Fishery Management Council canceled for the first time in the fishing for arctic spider crab in the Bering Sea. A decision taken after a drastic reduction in the population of this species which went from about 8 billion individuals in 2018 to only 1 billion in 2021.

Between 2021 and 2022 the number of male crabs would then decrease by 40%. While scientists don't have enough data to validate this hypothesis, temperatures around the Arctic are warming four times faster than the rest of the globe due to climate change.

Species living in cold waters are therefore directly threatened. The arctic spider crab is found mainly in areas where the water temperature is below 2 ° C. The reason for the demographic decline would depend on the ocean around Alaska which is becoming inhospitable for the species.

In Alaska, 7 billion fewer crustaceans

The regions around the Arctic have warmed four times faster than the rest of the planet. Global warming has triggered rapid loss of sea ice in the Arctic region, particularly in the Bering Sea of ​​Alaska.

A study published in Nature shows, by analyzing the growth rings of the trees of the remote Siberian peninsula of Yamal, that in 7600 years the summers in the Arctic have never been as warm as in modern times. The study, carried out in collaboration between Swiss, British and Russian research bodies, shows that the recent anthropogenic warming has interrupted a cooling trend that lasted millennia.

The reconstructed average temperature for the period 1920-2019 is equal to 13.47 ° C, with an estimated return time of over 4850 years. The estimated return time for the 1920–2019 mean air temperature suggests that warming over the past 100 years would have been virtually impossible at any other time in the past seven millennia and in the absence of climate change.