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Banana fungus parasite arrives in Colombia

The entire banana industry is on alert after a serious banana plant disease has spread to Colombia, one of the largest banana producing countries in the world. The fact that even this disease, previously found only in crops in Asia, has reached even South America is rekindling local concerns regarding the production of one of the most consumed fruits in the world.

The producers fear for the Global market, currently too dependent on the Cavendish banana, a type of banana known for its durability during sea journeys and in general for its resistance after it has been harvested.

The disease is caused by the parasitic fungus Fusarium oxysporum which most likely came from Asian countries. In recent weeks, confirmation was expected regarding the spread of this fungus also in Latin America, and confirmation came precisely from the analyzes carried out on some crops in Colombia.

According to experts, this parasite could also haunt the Cavendish banana after the Gros Michel quality, also known as Big Mike banana, was literally devastated in the 1950s by another strain of the same parasite that is spreading again today.

But this time, compared to the 1950s when the entire production moved to Cavendish, there is no “backup” banana to bet on if Cavendish also disappears.

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Reproduction of scallops monitored in real time with a new method

There are marine organisms that reproduce in the water reproductive cells, essentially sperm and gametes or eggs, to reproduce. It is very difficult to detect the release of these cells in real time and consequently, it is also difficult to study animals such as scallops (Pecten jacobaeus), a bivalve mollusc also present in the Mediterranean.

A group of researchers from the University of Maine and Bigelow Laboratory for Ocean Sciences has therefore devised a new method to study these “releases” by taking water samples and analyzing the environmental DNA. The result of the study focuses on a new method to manage wild mollusk populations, but also those in aquaculture, and generally shows a new approach in the context of the so-called eDNA, also called environmental DNA, ie the DNA that is not collected from living organisms but from samples taken from the environments in which they live.

To explain the importance of this research is Skylar Bayer, a researcher at the Milford Laboratory of the Northeast Fisheries Science Center and main author: “Knowing when and where marine organisms are generated is important to understand their demographic growth and their life cycle. Usually, monitoring the generation events in marine invertebrates, including marine scallops, can be a difficult task, so being able to track these events by sampling seawater could be enormously useful for the management and conservation practices of marine species.”

The same researcher admits that this method can also be used in the future to understand the deposition events of other marine animals such as corals and clams, practically in real-time.

The study was published in the Marine Ecology Progress Series.

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Increased absorption of carbon dioxide in the Antarctic ocean detected by new study

A new study published in Nature Climate Change shows a great increase in the absorption of carbon dioxide in the Antarctic Ocean. In particular, the researchers analyzed the marine areas off the western Antarctic peninsula, an area that is experiencing very rapid climatic changes with very clear temperature increases and ice melting in tow.

Understanding how carbon dioxide absorption is changing in the Antarctic Ocean is crucial to understanding the development of current climate change, as Michael Brown, a researcher at the Center for Ocean Observing Leadership at Rutgers University, points out.

The study analyzed 25 years of oceanographic measurements in the Antarctic ocean and found that the carbon dioxide absorption of this marine area increased nearly five times during the summer from 1993 to 2017.

When the melting of sea ice reaches a certain level, there will not be a sufficient amount of ice to prevent mixing of the wind in the upper ocean and this will cause a reduced absorption of the same carbon dioxide in the Antarctic ocean with harmful consequences for the whole globe.

The results of the new study are more than worrying considering that the Antarctic ocean absorbs about half of the carbon dioxide present in the atmosphere, even more in recent decades following the increasingly widespread use of fossil fuels as an energy source.

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Fusion of the Siberian permafrost will accelerate global warming

There is another environmental effect in progress will accelerate the greenhouse effect caused by humans: the release of organic matter from the Siberian permafrost.

This is the result of a team of Russian and US scientists who analyzed the composition of different layers of permafrost in eastern Siberia and published the results in a study in the Journal of Geophysical Research.

Permafrost is a soil covered with a layer of ice that can be of varying thickness but never seen. More and more research in recent years is linking this specific type of land to ongoing global warming, as well as the melting of Arctic ice.

Unlike the ice in the Arctic, however, the consequences of the melting of permafrost, in particular the Siberian one which represents the largest example, are not yet completely clear. This research seeks to fill this void by realizing what can be considered the first ever study on organic matter that is contained in the deeper layers of permafrost. They analyzed the terrain of the Kolyma river basin, eastern Siberia, to understand what happened in the distant past during the thawing periods to then relate this information to today’s events. Analyzing soil samples at various depths and belonging to different geological ages, they examined various deposits, from the Pleistocene to the Holocene, relatively well-preserved samples.

The results are explained by Alexander Zherebker, a scientist at the Skolkovo Institute of Science and Technology (SKOLTECH) and one of the authors of the study together with other colleagues from Lomonosov State University in Moscow: “We have identified the components that have undergone the greatest change and those that are the most sensitive to the action of microorganisms. It emerged that the biodegradable components are present both at great depth and very close to the permafrost surface. According to our projections, the Arctic region will have a strong impact on global warming very soon.”

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Shocking satellite image shows melting ice in Greenland

A satellite image shows us the dramatic level of Greenland ice melting. This time there is no need even to use data to get an idea.

The new image, published on the NASA website, shows how the branched network of glaciers around Greenland’s Sermilik fjord has changed over the past 47 years.

Comparing the image taken by the Landsat 8 satellite on 3 October 2019 with an image of the same area taken in 1972, the changes, in terms of melting ice and the emergence of the underlying soil are more than clear, shocking in some ways.

The surface of fusion, which in the images appears darker than the surface covered with ice, is much more extensive in 2019 than in 1972.

The phenomenon of ice melting has left only an intricate tangle of sea ice that will probably soon melt too.

“Now there is much more bare rock visible, which was previously covered in ice,” reports Christopher Shuman, a glaciologist at the University of Maryland, who also adds that there are dozens of examples like this only in this area.