Home Tech World’s largest fish breeding colony found in Antarctica

World’s largest fish breeding colony found in Antarctica

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World’s largest fish breeding colony found in Antarctica

***EMBARGOED UNTIL 16.00 GMT, THURS JAN 13 (11.00 ET)*** Nests of icefish. See SWNS story SWNNfish. The world's largest breeding colony of fish has been discovered in Antarctica. It covers at least 150 square miles - and includes about 60 million active nests. The unprecedented population represents a biomass of more than 60,000 tons - or over 135 million lbs. Most were occupied by a single adult guarding more than 1,700 eggs. There were many fish carcasses within and near the site. It suggests the notothenioids, or icefish, play an important role in the wider food web. Its believed the colony is utilised heavily by seals and other predators.

Nests of icefish found in Antarctica. (Credits: AWI OFOBS Team / SWNS)

The world’s largest breeding colony of fish has been found in Antarctica.

It covers a minimum of 150 sq. miles – and consists of about 60 million lively icefish nests.

The unprecedented inhabitants represents a biomass of greater than 60,000 tons – or over 135 million lbs.

Most had been occupied by a single grownup guarding greater than 1,700 eggs. There had been many fish carcasses inside and close to the location.

It suggests the notothenioids, or icefish, play an vital function within the wider meals internet.

Its believed the colony is utilised closely by seals and different predators.

Lead creator Dr Autun Purser mentioned: ‘An ideal many seals spend a lot of their time in shut proximity to the fish nests.

‘We know this from historic monitoring knowledge and recent monitoring knowledge from our cruise. The nests are precisely the place the hotter water is upwelling.

‘These facts may be coincidence, and more work is needed, but the recorded seal data show seals do indeed dive to the depths of the fish nests, so may well be dining on these fish.’

The mysterious icefish colony is positioned within the southern Weddell Sea on the jap facet of the Peninsula.

Their bodily fluids comprise antifreeze proteins that allow them to outlive the very chilly temperatures of the Southern Ocean.

As a end result, blood is much less thick and sticky – growing provide of oxygen to organs.

Dr Purser, of the Alfred Wegener Institute, Bremerhaven, mentioned: ‘Our most vital discovering is the pure existence of such an in depth icefish brooding colony.

‘A few dozen nests have been observed elsewhere in the Antarctic – but this find is orders of magnitude larger.’

Last February the German staff surveyed the Filchner ice shelf – an unlimited slab that has floated off the land onto the ocean.

They used an underwater digital camera ‘sledge’ known as OFOBS (Ocean Floor Observation and Bathymetry System.

Explained Dr Purser: ‘Basically it is a massive, towed machine, weighing one ton, which we tow behind the icebreaker RV Polarstern at a pace of 1 to 4 kilometres per hour.

‘We tow this at a height of about 1.5 to 2.5 metres above the seafloor, recording videos and acoustic bathymetry data.’

***EMBARGOED UNTIL 16.00 GMT, THURS JAN 13 (11.00 ET)*** The RV Polarstern in the Wendall Sea, Antarctica. See SWNS story SWNNfish. The world's largest breeding colony of fish has been discovered in Antarctica. It covers at least 150 square miles - and includes about 60 million active nests. The unprecedented population represents a biomass of more than 60,000 tons - or over 135 million lbs. Most were occupied by a single adult guarding more than 1,700 eggs. There were many fish carcasses within and near the site. It suggests the notothenioids, or icefish, play an important role in the wider food web. Its believed the colony is utilised heavily by seals and other predators.

The RV Polarstern within the Wendall Sea, Antarctica. (Credits: AWI – Tim Kavelage / SWNS)

It is pulled on a particular fibre-optic and energy cable usually at a pace of about one half to at least one knot.

Live photographs had been transmitted from 535 to 420 metres right down to screens aboard the analysis ship.

The longer the mission lasted, the extra the thrill grew – lastly ending in disbelief.

Nest adopted nest. Precise evaluations recognized a mean one breeding website per three sq. metres – with as much as two per sq. metre.

Mapping prompt it prolonged throughout a area roughly equal to an island the scale of Malta.

Dr Purser mentioned: ‘The idea such a huge breeding area of icefish in the Weddell Sea was previously undiscovered is totally fascinating.’

The Polarstern icebreaker has been exploring it for 4 many years. Only particular person Neopagetopsis ionah fish or small clusters of nests had ever been detected.

They knew the realm included an upwelling 2C hotter than surrounding backside waters. But the remainder of what they discovered was a shock.

Dr Purser mentioned: ‘We did not know to expect any sort of fish nest ecosystem.’ That half, he provides, got here as a ‘total surprise.’

Dr Purser mentioned: ‘After the spectacular discovery of the various fish nests, we thought of a method on board to learn the way massive the breeding space was – there was actually no finish in sight.

‘The nests are three quarters of a metre in diameter – so they’re much bigger than the buildings and creatures, a few of that are solely centimetres in dimension, that we usually detect with the OFOBS system.

‘So, we had been in a position to enhance the peak above floor to about three metres and the towing pace to a most of three knots, thus multiplying the realm investigated.

‘We covered an area of 45,600 square metres and counted an incredible 16,160 fish nests on the photo and video footage.’

***EMBARGOED UNTIL 16.00 GMT, THURS JAN 13 (11.00 ET)*** Nests of icefish. See SWNS story SWNNfish. The world's largest breeding colony of fish has been discovered in Antarctica. It covers at least 150 square miles - and includes about 60 million active nests. The unprecedented population represents a biomass of more than 60,000 tons - or over 135 million lbs. Most were occupied by a single adult guarding more than 1,700 eggs. There were many fish carcasses within and near the site. It suggests the notothenioids, or icefish, play an important role in the wider food web. Its believed the colony is utilised heavily by seals and other predators.

The unprecedented inhabitants represents a biomass of greater than 60,000 tons – or over 135 million lbs. (Credits: AWI OFOBS Team / SWNS)

The spherical fish nests might be clearly recognized – about six inches deep and two-and-a-half toes in diameter.

They stood out from the in any other case muddy seabed because of a round central space of small stones. Several varieties had been distinguished.

Some had been ‘active’ with between 1,500 and a pair of,500 eggs and guarded in three-quarters of circumstances by an grownup icefish of the species Neopagetopsis ionah.

Others contained solely eggs. There had been additionally unused nests, within the neighborhood of which both solely a fish with out eggs might be seen, or a useless fish.

The researchers used OFOBS’s longer-range however lower-resolution facet scan sonars – which recorded over 100,000 nests – to work out distribution and density.

They had been a well-liked vacation spot for seals in the hunt for meals. Transmitters connected to the marine mammals confirmed 90 p.c of diving actions occurred there.

It’s prone to be essentially the most spatially intensive contiguous fish breeding colony found worldwide to this point.

Bettina Stark-Watzinger, German Federal Research Minister, mentioned: ‘My congratulations to the researchers concerned on their fascinating discovery.

‘This discovery can make an important contribution towards protecting the Antarctic environment.’

The findings reported within the journal Current Biology reveal a globally distinctive ecosystem – backing requires a regional Marine Protected Area within the Southern Ocean.

It could be below the Convention on the Conservation of Antarctic Marine Living Resources umbrella.


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