Icefish in the Weddell Sea. Credit: PS118, AWI OFOBS group
Scientists reporting in the journal Current Biology on January 13, 2022, have actually found a huge breeding nest of notothenioid icefish in Antarcticas southern Weddell Sea. They approximate that the nest covers at least 240 square kilometers and consists of about 60 million active nests. The unprecedented colony represents a fish biomass of more than 60,000 heaps (or over 135 million pounds).
” Our most essential finding is the pure existence of such an extensive icefish brooding nest,” says Autun Purser of the Alfred Wegener Institute in Bremerhaven, Germany. “A couple of dozen nests have actually been observed somewhere else in the Antarctic, however this discover is orders of magnitude bigger.”
Purser and colleagues made the discovery while surveying the Filchner ice rack using the Ocean Floor Observation and Bathymetry System (OFOBS). “Basically this is a large, towed device, weighing one heap, which we tow behind the icebreaker recreational vehicle Polarstern at a speed of one to four kilometers per hour,” he discusses. “We tow this at a height of about 1.5 to 2.5 meters above the seafloor, tape-recording videos and acoustic bathymetry information.”
This image shows the RV Polarstern in the Wendall Sea, Antarctica. Credit: AWI– Tim Kavelage
The researchers were particularly interested in this area of the seafloor because they knew it consisted of an upwelling of water 2 degrees Celsius warmer than the surrounding bottom waters. The rest of what they found, nevertheless, was rather unexpected.
” We did not understand to expect any sort of fish nest environment,” Purser states. That part, he includes, came as a “overall surprise.”
The bulk of the nests they discovered were occupied by a single adult fish securing more than 1,700 eggs. They also observed various deceased fish carcasses within and near the nesting nest, suggesting that the fish play an essential function in the larger food web. While more study is needed, they suspect the colony is made use of heavily by predators such as Weddell seals.
Icefish in the Weddell Sea. Credit: PS118, AWI OFOBS group
” A great lots of Weddell seals invest much of their time in close proximity to the fish nests,” Purser says. These truths may be coincidence, and more work is needed, however the recorded seal data reveal seals do certainly dive to the depths of the fish nests, so might well be dining on these fish.”
The findings reveal an internationally special community, according to the researchers. They also offer support for the facility of a regional Marine Protected Area in the Southern Ocean under the Convention on the Conservation of Antarctic Marine Living Resources umbrella..
The scientists have actually now deployed two electronic camera systems to keep an eye on the icefish nests until a research study vessel returns. The hope is that pictures taken multiple times a day will yield new insights on the functions of this recently found community. Purser states he has plans to return in April 2022 for studies of the seafloor in locations of the northeast Weddell Sea.
For more on this research study, see “Spectacular Discovery” in Antarctica: Massive Icefish Breeding Colony With 60 Million Nests.
Referral: “A large icefish reproducing colony found in the Antarctic” by Autun Purser, Laura Hehemann, Lilian Boehringer, Sandra Tippenhauer, Mia Wege, Horst Bornemann, Santiago E.A. Pineda-Metz, Clara M. Flintrop, Florian Koch, Hartmut H. Hellmer, Patricia Burkhardt-Holm, Markus Janout, Ellen Werner, Barbara Glemser, Jenna Balaguer, Andreas Rogge, Moritz Holtappels and Frank Wenzhoefer, 13 January 2022, Current Biology.DOI: 10.1016/ j.cub.2021.12.022.
This work was supported by AWI, the H2020 project INTAROS, and the PACES Program of the Helmholtz Association.
Scientists reporting in the journal Current Biology on January 13, 2022, have discovered a massive breeding colony of notothenioid icefish in Antarcticas southern Weddell Sea. They approximate that the colony covers at least 240 square kilometers and includes about 60 million active nests.” A great many Weddell seals spend much of their time in close proximity to the fish nests,” Purser states. These facts may be coincidence, and more work is needed, but the tape-recorded seal information show seals do certainly dive to the depths of the fish nests, so might well be dining on these fish.”
The scientists have now released 2 cam systems to keep track of the icefish nests until a research vessel returns.
