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“Spectacular Discovery” in Antarctica: Massive Icefish Breeding Colony With 60 Million Nests – SciTechDaily

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Nests of icefish. Credit: AWI OFOBS Team

Researchers detect around 60 million nests of Antarctic icefish over a 240 square kilometers area in the Weddell Sea.

Near the Filchner Ice Shelf in the south of the Antarctic Weddell Sea, a research team has found the world’s largest fish breeding area known to date. A towed camera system photographed and filmed thousands of nests of icefish of the species Neopagetopsis ionah on the seabed. The density of the nests and the size of the entire breeding area suggest a total number of about 60 million icefish breeding at the time of observation. These findings provide support for the establishment of a Marine Protected Area in the Atlantic sector of the Southern Ocean. A team led by Autun Purser from the Alfred Wegener Institute publish their results in the current issue of the scientific journal Current Biology.

The joy was great when, in February 2021, researchers viewed numerous fish nests on the monitors aboard the German research vessel Polarstern, which their towed camera system transmitted live to the vessel from the seabed, 535 to 420 meters below the ship, from the seafloor of the Antarctic Weddell Sea. The longer the mission lasted, the more the excitement grew, finally ending in disbelief: nest followed nest, with later precise evaluation showing that there were on average one breeding site per three square meters, with the team even finding a maximum of one to two active nests per square meter.

Eastern Break-Off Edge of the Iceberg

Eastern break-off edge of the iceberg. Credit: Alfred-Wegener-Institut / Ralph Timmermann

The mapping of the area suggests a total extent of 240 square kilometers, which is roughly the size of the island of Malta. Extrapolated to this area size, the total number of fish nests was estimated to be about 60 million. “The idea that such a huge breeding area of icefish in the Weddell Sea was previously undiscovered is totally fascinating,” says Autun Purser, deep-sea biologist at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) and lead author of the current publication. After all, the Alfred Wegener Institute has been exploring the area with its icebreaker Polarstern since the early 1980s. So far, only individual Neopagetopsis ionah or small clusters of nests have been detected here.

The unique observations are made with a so-called OFOBS, the Ocean Floor Observation, and Bathymetry System. It is a camera sledge built to survey the seafloor of extreme environments, like ice-covered seas. It is towed on a special fiber-optic and power cable normally at a speed of about one half to one knot, about one and half meters above the seafloor. “After the spectacular discovery of the many fish nests, we thought about a strategy on board to find out how large the breeding area was — there was literally no end in sight. The nests are three quarters of a meter in diameter — so they are much larger than the structures and creatures, some of which are only centimeters in size, that we normally detect with the OFOBS system,” Autun Purser reports. “So, we were able to increase the height above ground to about three meters and the towing speed to a maximum of three knots, thus multiplying the area investigated. We covered an area of 45,600 square meters and counted an incredible 16,160 fish nests on the photo and video footage,” says the AWI expert.

Fish Nests in Weddell Sea

Fish nests in Weddell Sea. Credit: PS124, AWI OFOBS team

Based on the images, the team was able to clearly identify the round fish nests, about 15 centimeters deep and 75 centimeters in diameter, which were made distinct from the otherwise muddy seabed by a round central area of small stones. Several types of fish nests were distinguished: “Active” nests, containing between 1,500 and 2,500 eggs and guarded in three-quarters of the cases by an adult icefish of the species Neopagetopsis ionah, or nests which contained only eggs; there were also unused nests, in the vicinity of which either only a fish without eggs could be seen, or a dead fish. The researchers mapped the distribution and density of the nests using OFOBS’s longer-range but lower-resolution side scan sonars, which recorded over 100,000 nests.

The scientists combined their results with oceanographic and biological data. The result: the breeding area corresponds spatially with the inflow of warmer deep water from the Weddell Sea onto the higher shelf. With the help of transmitter equipped seals, the multidisciplinary team was also able to prove that the region is also a popular destination for Weddell seals. 90 percent of the seals’ diving activities took place within the region of active fish nests, where they presumably go in search of food. No wonder, the researchers calculate the biomass of the ice fish colony there at 60 thousand tonnes.

Icefish Nest Weddell Sea

Icefish Nest in Weddell Sea. Credit: PS124, AWI OFOBS team

With its biomass, this huge breeding area is an extremely important ecosystem for the Weddell Sea and, according to current research, likely to be the most spatially extensive contiguous fish breeding colony discovered worldwide to date, the experts report in the publication in Current Biology.

German Federal Research Minister Bettina Stark-Watzinger said: “My congratulations to the researchers involved on their fascinating discovery. After the MOSAiC expedition, German marine and polar research has once more reaffirmed its outstanding position. German research vessels are floating environmental research laboratories. They continue to sail the polar seas and our oceans almost non-stop, serving as platforms for science aimed at generating important findings to support climate and environmental protection. Funding by the Federal Ministry of Education and Research (BMBF) provides German marine and polar research with one of the most state-of-the-art research vessel fleets worldwide. This discovery can make an important contribution towards protecting the Antarctic environment. The BMBF will continue to work towards this goal under the umbrella of the United Nations Decade of Ocean Science for Sustainable Development that runs until 2030.”

For AWI Director and deep-sea biologist Prof. Antje Boetius, the current study is a sign of how urgent it is to establish marine protected areas in Antarctica. “This great discovery was enabled by a specific under-ice survey technology we developed during my ERC Grant. It shows how important it is to be able to investigate unknown ecosystems before we disturb them. Considering how little known the Antarctic Weddell Sea is, this underlines all the more the need of international efforts to establish a Marine Protected Area (MPA),” Antje Boetius classifies the results of the study, in which she was not directly involved. A proposal for such an MPA has been prepared under the lead of the Alfred Wegener Institute and is defended since 2016 by the European Union and its member states as well as other supporting countries in the international Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR).

Antje Boetius adds: “Unfortunately, the Weddell Sea MPA has still not yet been adopted unanimously by CCAMLR. But now that the location of this extraordinary breeding colony is known, Germany and other CCAMLR members should ensure that no fishing and only non-invasive research takes place there in future. So far, the remoteness and difficult sea ice conditions of this southernmost area of the Weddell Sea have protected the area, but with the increasing pressures on the ocean and polar regions, we should be much more ambitious with marine conservation.”

Reference: “A vast icefish breeding colony discovered 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

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Scientists Reveal How Whales Escape Drowning When They Consume Food Underwater – Nature World News

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The feeding process of whales usually involves taking in a large amount of water, how they do this without drowning could be an important question asked out of curiosity.  

(Photo : Pixabay)

Feeding Mechanism of Whale

A lung feeding whale has a fleshy bulb in its mouth called the ‘oral plug’, this bulb moves backward to seal off the upper airways during feeding, while their larynx closes to block the lower airways preventing water from entering the lungs while they feed, according to Phys.org.

“It’s kind of like when a human’s uvula moves backward to block our nasal passages, and our windpipe closes up while swallowing food,” according to Dr. Kelsey Gil, the study’s lead author and also a postdoctoral researcher in the department of zoology.

This lung-feeding predator engulfs their prey along with gallons of water that are sometimes larger than their body, the group of whales according to Dr. Gil involved in this process includes the humpback and the blue whale, Earth’s largest animal.

The fin whale which is also a lung feeding whale is specifically studied, this is because researchers discovered that the oral plug needs to move to the back of the animal’s head in order to allow food to pass to the esophagus thereby blocking the nasal passages anytime the whale try to swallow.

At the same time, cartilages close the entrance of the larynx, and the laryngeal sac moves upwards, blocking off the airways below.

Also Read: Three Pregnant Killer Whales Might Save Their Population From the Brink of Extinction

How Lunge-feeding Evolved

Mr. Gil said researchers haven’t noticed similar protective mechanism both in other animals and in the literature. Most of researchers’ knowledge concerning whales and dolphins are gotten from toothed whales.

But toothed whales possess a very different respiratory tracts and so many makes similar supposition about lunge-feeding whales. The major component and evolution of lunge-feeding whales depend solely on the oral plug.

According to Dr. Robert Shadwick, a senior author and also a professor in the UBC department of zoology, “Bulk filter-feeding on krill swarms is highly efficient and the only way to provide the massive amount of energy needed to support such large body size.

This would not be possible without the special anatomical features we have described.” 

Tail of a whale

(Photo : Andrea Holien)

Further Research on Whale’s Feeding Mechanism

Due to less advancement of technology, working on the anatomy of whales involves dissection of dead whales which is quite difficult and comes with lots of challenges.

Dr. Gil and his colleagues had performed their dissection on dead whales in Iceland in 2018 and had expressed how thrilling it would have been to have a more advanced technology that can give a more detailed picture of whales feeding while they are alive.

Since there are a lot of human impacts that affect food chains, and discovering how whales eat and the amount of food they consume, it’s important to gain as much knowledge as possible so that the animals and their eco systems can be protected.

Related Article: Scientists Claim Whales Have Previously Walked In North America Coastline

For more news, updates about whales and similar topics don’t forget to follow Nature World News!

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Canadian Scientist Goes Back in Time Using the World's Biggest Space Telescope – Optic Flux

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A group of astrophysicists may soon have a key to unraveling the puzzle of life’s beginnings.

On December 25, the James Webb Space Telescope was launched into orbit from French Guiana, South America.

Webb is the biggest and most powerful space telescope ever built by NASA, the National Aeronautics and Space Administration, at the cost of $10 billion US.

Tyrone Woods, a Canadian astronomer, aims to utilize it to go through the time and uncover the earliest stars ever produced.

“We’re going to be able to look back into this earliest epoch of the universe,” Woods stated.

Woods, a Plaskett Fellow at the National Research Council of Canada’s Herzberg Astronomy and Astrophysics Research Centre in Victoria, B.C., is originally from Edmonton.

The Hubble Space Telescope was launched in 1990, and NASA claims Webb as its successor.

On December 25, Arianespace's Ariane 5 rocket launches from French Guiana, carrying NASA's James Webb Space Telescope.
On December 25, Arianespace’s Ariane 5 rocket launches from French Guiana, carrying NASA’s James Webb Space Telescope.

NASA, the European Space Agency, and the Canadian Space Agency collaborated on the new telescope.

The project has been in the works for decades.

Webb’s mirror is substantially bigger than Hubble’s, allowing it to capture more light and see farther back in time.

“Light has a fixed speed. It doesn’t travel infinitely fast. It takes time,” Woods said on CBC Edmonton’s Radio Active.

Many stars are millions, if not billions, of light-years distant from Earth, even though light travels at 300,000 kilometers per second.
Some of the stars that we see in the night sky may no longer exist.

NASA’s James Webb Space Telescope was placed on top of the Ariane 5 rocket that will send it into space from Europe’s Spaceport in French Guiana on December 11.

Stellar Nurseries

Stellar nurseries are places of dust and gas where stars are born.
Woods’ team used computer simulations to create a cosmic roadmap to aid in the search for the earliest stars.

“So conventionally, we had always thought of the first stars as being so very compact and very blue. We’ve seen that in some of them [nurseries of the very first stars], they would be the perfect conditions for making really massive, really bloated, really red stars.”

HD 140283, the Methuselah Star, is now the oldest known star.
It is thought to be 14 billion years old, around the same age as the universe.

Webb is an infrared telescope, which means it can see the light that human eyes can’t see.
Because infrared is a wavelength that our planet produces, it’s feasible that concentrating on infrared light may lead to the discovery of a planet identical to Earth.
Woods added they’ll be searching in the surroundings around some huge clusters of galaxies for a magnified light from behind them to obtain a very, really deep exposure of the early cosmos.

Aside from the origins of the stars, Woods thinks that the new telescope will aid scientists in discovering the first black hole, understanding how gases assemble in the cosmos and learning more about how our own solar system was created.

After traveling 1.5 million kilometers from Earth to its targeted orbit around the sun, Webb will spend the next several months deploying its mirrors and enormous sunshield and cooling down before seeing into the furthest regions of the cosmos.

“Over the subsequent year, we’re going to start to see the first really exciting results,” Woods added.

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Canadian scientist examines melting Antarctic glacier, potential sea level rise – Williams Lake Tribune

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As icebergs drifted by his Antarctica-bound ship, David Holland spoke this week of how the melting glacier he’s cruising towards may contain warning signals for the coasts of far-off Canada.

The atmospheric and ocean scientist from Newfoundland is part of an expedition to one of the world’s most frigid and remote spots — the Thwaites glacier in the western portion of the continent — where he’ll measure water temperatures in an undersea channel the size of Manhattan.

“The question of whether sea level will change can only be answered by looking at the planet where it matters, and that is at Thwaites,” said Holland, director of the environmental fluid dynamics laboratory at New York University, during a satellite phone interview from aboard the South Korean icebreaker Araon.

It’s over 16,000 kilometres from Holland’s hometown in Brigus, N.L., on Conception Bay, to the site about 100 kilometres inland from the “grounding zone” where the Thwaites’ glacier leaves the continent and extends over the Pacific.

The team’s 20,000 tonnes of drilling gear will be assembled to measure the temperatures, salinity and turbulence of the Pacific waters that have crept underneath and are lapping away at the guts of the glacier.

“If it (the water) is above freezing, and in salt water this means above -2 centigrade, that’s not sustainable. A glacier can’t survive that,” said Holland.

Since 2018, more than 60 scientists from the International Thwaites Glacier Collaboration group have been exploring the ocean and marine sediments, measuring warming currents flowing toward the deep ice, and examining the stretching, bending, and grinding of the glacier over the landscape below.

The Florida-sized Thwaites glacier faces the Amundsen Sea, and researchers have suggested in journal articles over the past decade it may eventually lose large amounts of ice because of deep, warm water driven into the area as the planet warms. Some media have dubbed Thwaites the “doomsday glacier” due to estimates that it could add about 65 centimetres to global sea level rise.

Holland notes current research models mainly suggest this would happen over several centuries, however there are also lower probability theories of “catastrophic collapse” occurring, where the massive ice shelf melts in the space of decades. “We want to pay attention to things that are plausible, and rapid collapse of that glacier is a possibility,” he said.

While Holland looks at the undersea melting, other scientists are examining how the land-based portions of Antarctic glaciers are losing their grip on points of attachment to the seabed, potentially causing parts to detach. Still other researchers point to the risk of initial fractures causing the ice shelf to break, much like a damaged car windshield.

All of the mechanisms must be carefully observed to prove or disprove models on the rates of melting, said Holland.

“If the (water-filled) cave beneath the glacier we’re studying gets bigger, then Antarctica is losing ice and retreating, and if the cave collapses on itself, then (the cave) will disappear. This is how Antarctica can retreat, these kinds of specific events,” he said.

The implications of the glacier work reach back to Atlantic Canada — which along with communities along the Beaufort Sea and in southwestern British Columbia is the region most vulnerable to sea level rise in the country, according to federal scientists.

Everything from how to calculate the future height of dikes at the low-lying Chignecto Isthmus — the narrow band of land that connects Nova Scotia to the rest of the country — to whether the Fraser River lowlands may face flooding is potentially affected by glacial melting in Antarctica, he said.

Scenarios where Antarctica ice melts more quickly than expected are briefly discussed in the 2019 federal report Canada’s Changing Climate. Based largely on Intergovernmental Panel on Climate Change reports that refer to them as low-probability “tipping point” theories, the 2019 report invoked the possibility of one metre of sea level rise by 2100.

However, Blair Greenan, a federal oceanographer who oversaw the relevant chapter of the report, said in a recent interview that a rise in global sea levels approaching two metres by 2100 and five metres by 2150 “cannot be ruled out” due to uncertainty over ice sheet processes like Thwaites.

“We don’t know, nobody knows,” Holland said. “But it’s plausible these things can change, and several feet of sea level change would have a major impact on Atlantic Canada. What’s needed is glacier forecasting that resembles the kinds of accuracy that weather forecasting currently provides.”

However, collecting glacier forecast data is a daunting undertaking in the short period — from late January until mid-February — when scientists can safely take readings. Helicopters will be ferrying a hot water drill, 30 barrels of fuel and water to Holland’s site beginning near the end of January. The drill will have to penetrate over a kilometre of ice to reach the 300 metres of undersea channel to take measurements.

As the data is collected, some scientists question whether there’s really much for Canadian coastal residents to worry about at this stage.

One study by Ian Joughin, a University of Washington glaciologist, has suggested Thwaites will only lose ice at a rate that creates sea level rise of one millimetre per year — and not until next century. At that rate it would take 100 years for sea levels to rise 10 centimetres.

In a telephone interview last week, Joughin said planning coastal protection and other measures for the more extreme scenarios may not be cost effective at this point, as it may take up to a century before the major risks starts to unfold.

However, Joanna Eyquem, a Montreal-based geoscientist who is studying ways to prepare infrastructure for rising sea levels, said in a recent email that glacier research shows sea level forecasts “are constantly evolving,” and adaptation efforts need to be quicker.

“The question is: How desperate does the situation need to be before we take action?” she asked.

READ MORE: Expert panel says Canada needs to ‘up its game’ on climate data to better adapt

Michael Tutton, The Canadian Press


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