A new international study has been launched on the Ukrainian research vessel Noosphere, which is currently in the Antarctic 🇦🇶. As part of the cooperation between Polish and Ukrainian scientists, samples of marine fauna were taken from the bottom of the Southern Ocean for the first time. This was reported by the National Antarctic Research Center, UNN reports.
Details
A special bottom trawl was used for the survey. The study took place in Penola Strait (near the Akademik Vernadsky station) at three different depths.
Different marine organisms were found on each of them:
- At a depth of 250 meters, sponges, large starfish, and holothuria (also called sea cucumbers because of their similar shape) dominated;
- At a depth of 200 m, medium-sized species of starfish, snails, large polychaetes, and ophiurae (also called snake-tails because of their peculiar way of moving: when they crawl along the bottom, their rays wriggle like snakes) were most common;
- At a depth of 120 m, various species of needlefish and colonies of sedentary bryozoans were collected.
The samples are currently stored on the ship in special freezers. After delivery to the laboratory on the "big land," scientists will isolate and sequence the genetic code of the selected organisms and study how much metal is present in their mineral skeletons.
Why is it important
One of the most advanced methods of studying marine ecosystems is environmental DNA analysis. This method can identify tens or hundreds of species of living organisms in a single water sample using specific molecular markers. This saves time and money, and causes much less environmental damage compared to traditional research methods that require the mandatory capture of living creatures.
However, for this method to work, it is first necessary to collect a database of DNA marker sequences of local species (barcodes), which will play the same role in further research as a fingerprint database for forensic scientists. The first "catch" of Noosphere is intended to develop the database of Antarctic fauna barcodes.
Why determine the metal content of animal skeletons?
Climate change leads to an increase in the temperature of seawater and its oxidation (lowering the pH value). In more acidic and warmer water, the physiology of animals changes, in particular, they begin to absorb metals from the water much more intensively and deposit them in skeletal elements such as bones, shells, carapaces, etc.
The skeleton contaminated with metals becomes weaker. Water oxidation also has a negative impact on animal shells made of calcium carbonate, as it dissolves in an acidic environment. Together with the accumulation of metals, this makes the skeletal support of marine life fragile and vulnerable.
Therefore, thanks to this research, scientists will be able to assess the sensitivity/resilience of aquatic invertebrates to changes in the chemical composition of the Southern Ocean and identify groups that are primarily threatened by the effects of climate change in the Antarctic.
AddendumAddendum
On the Polish side, researchers from the Polish Academy of Sciences and the University of Gdańsk are taking part in the study. The current joint sampling of benthic marine fauna is the beginning of a new area of scientific cooperation between Ukraine and Poland. It is expected to develop into a long-term joint project funded by the National Science Center of the Republic of Poland.