Rapidly melting glaciers release bacteria into ecosystems that worry scientists

Rapidly melting glaciers due to global warming are releasing countless bacteria into rivers. In addition to presenting a danger to the health of humans and animals, these bacteria can transform an entire ecosystem.

Over the next 80 years, rising temperatures will release hundreds of thousands of tons of bacteriabacteria in aquatic environments around glaciers. A study published in Communications Earth & Environment presents the findings of researchers who studied 10 glacial sites across thenorthern hemispherenorthern hemisphere : the Alps, Greenland, Svalbard,ArcticArctic canadian. As one of the study’s authors, Arwyn Edwards, points outfrom Aberystwyth University, glaciers are not only large massesmasses of frozen water, they are also entire ecosystems”. Who says ecosystem, says presence of life, and this one is essentially represented in the form of microorganismsmicroorganisms in glaciers. But much more, because in melting, the water of the glaciers carries with it mineralsminerals, gasgas, sedimentsediment and some mattermatter organic from the mountains. This organic matter had until now been trapped under the ice for thousands, even millions of years.

Bacteria from glaciers are capable of transforming biodiversity

One of the main concerns of researchers is that the meltingmelting ice cream is currently so fast that they don’t have enough time to analyze all the different types of bacteria that are being released at large speedspeed ! Several tens of thousands of microbes per millimeter of water are thus discharged continuously. The microbes present in glacial water can also fertilize ecosystems and modify environments, since they are the basis of life, they can influence the development of certain other microorganisms, allowing some to be favored and with the further consequence of causing others to disappear. In the longer term, it is biodiversitybiodiversity rivers and lakes which could therefore be completely modified: some speciesspecies animals and plants will disappear while others will emerge or proliferate. And at the end of the food chainfood chainis the human species, totally dependent on waterways.

Worsening global warming and new perspectives for science

Another surprising consequence results from the melting of glaciers: bacteria and algaealgae present in icy environments usually contain pigments to protect against the harmful rays of the SunSun. But these pigments, by absorbing theenergyenergy solar, could contribute even more to the global warmingglobal warming which is already accelerating the melting of the ice. In addition to this living matter, the equivalent of 650,000 tons of carboncarbonthe main greenhouse gas, is released every year into rivers, lakes, fjordsfjords and oceans of the northern hemisphere.

However, the researchers point out that this new arrival of bacteria and microbes is not only negative and also opens up new perspectives for science: it is not impossible that some of them could allow medical advances, and in particular the creation of new antibioticsantibioticsfor example.

Article of Karine DurandKarine Durand published on July 10, 2022

Chinese scientists have discovered nearly 1,000 microbes, bacteria and viruses trapped in glaciers on the Tibetan Plateau. The melting of the ice will gradually release these micro-organisms which are several thousand years old.

The Tibetan plateau is considered the third pole with 46,000 glaciers: it has the third largest concentration of ice in the world, after the North and South poles. The surfaces of glaciers are far from devoid of life, they contain a large number of different forms of life, such as bacteria, algae, mushroomsmushrooms or even archaeaarchaea. These microorganisms play an important role in theecologyecology glaciers. It was in this environment that a team of Chinese scientists discovered 968 different species of microbes. These microbes live in extreme conditions: freezing temperatures, high levels of solar radiation, virtually no food sources. They have the ability to freeze and thaw depending on the temperatures. Chinese scientists are currently conducting a research projecttitled the “ catalog of genomesgenomes and GenoaGenoa of the Tibetan Glacier » (TG2G), which is destined to be supplemented by the discovery of new organisms as research progresses.

80% of Tibetan glaciers are melting

The Tibet Plateau, an area of ​​2.5 million square kilometres, is an important source of water supply for the Asian cities bordering it. The so-called “Asian water tower” is heating up three times faster than the global average. According to the World Meteorological Organizationmost of the Tibetan plateau experienced a decrease in snow days between 1980 and 2016, with an average decrease of less than 2 days/year over nearly half of the region, and more than 4 days/ year in some areas. Climate change has already caused 80% of the plateau’s glaciers to shrink.

Scientists believe that it is necessary to list the microbes of these glaciers in order to assess the consequences, and possible problems, with the melting of the ice, and therefore with the dispersion of these microbes. The team has already counted 3,241 genomes from 21 glaciers between 2016 and 2020. Some 82% of the genomes are new species, 11% of these species were found on the same glacier and 10% were found on all glaciers studied. These glaciers are real “recorders” of life in the past, since they trap 10,000-year-old microbes that can come back to life when the conditions are right. In 2021, another study of Chinese scientists had identified 33 viruses (including 28 unknown) trapped in the Guliya ice shelf in Tibet. The age of some of these discovered viruses had been estimated at more than 15,000 years.

Microbes, viruses, carbon and methane are released by global warming

How do microbes, viruses, bacteria and fungi get locked up in ice? According to the Chinese researchers, these viruses come mainly from plants and the soil in which they grew. Dust from this soil 10,000 or 15,000 years ago was simply trapped in the ice, as were large quantities of carbon and methane: 12 million tonnes of carbon would be locked up in the Tibetan ice. The melting of the ice linked to global warming therefore presents a multiple danger, already in motion: the dispersion in the atmosphere of these greenhouse gases which will once again aggravate the warming, but also of these micro-organisms in the land. and Tibetan waters.

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