World’s Largest Fish Breeding Area Discovered In Antarctica – Free PDF Download

• The world’s largest fish breeding ground has been discovered in
• Around 60 million icefish nests were found on the ocean floor in the south of the Weddell Sea.

• The nests were concentrated in a 92-square-mile area – around the size of Kettering – and there were sometimes two per square metre. Each nest contained up to 2,500 eggs.
• Researchers on the German research vessel Polarstern came across the breeding ground by accident when carrying out routine observations with a camera towed up to 535m underwater.
• The Alfred Wegener Institute (AWI) has been exploring the Weddell sea since the early 1980s but until this discovery had only ever found small clusters of nests.
• The area of the breeding ground was known to the researchers for a process called upwelling, where cold water rises to the surface and leaves the deeper parts warmer.
• It was found to be a popular destination for Weddell seals. The researchers tracked a number of seals and found that 90 per cent of their diving took place around the nests.
• A great many seals spend much of their time in close proximity to the fish nests.
• The researchers observed that the colony occupied an unusually warm patch of deep water, with temperatures up to about 35 degrees Fahrenheit — practically toasty compared to other Antarctic waters.
• Researchers said the discovery of the breeding grounds showed that marine conservation in Antarctica needs to be improved.
• The findings reveal a globally unique ecosystem, according to the researchers. They also provide support for the establishment of a regional Marine Protected Area in the Southern Ocean under the Convention on the Conservation of Antarctic Marine Living Resources umbrella.

Seal Food??

• While the Weddell Sea is covered with sea ice all year round, the ice is relatively thin — three feet thick — meaning that photosynthesis can still take place and life can thrive.
• The Weddell Sea floor is far from barren, with sea sponges, corals, octopuses and star fish lurking along the seabed.
• Around 2,000 seals also live in the area and likely dive in the breeding area and feed on the icefish, although they didn’t have definitive evidence.
• While there were species of freshwater fish that make similar kinds of nest, scientists had “never seen any colonies like this in the deep sea.”

About the Ice Fish

• Ice fish are a unique group of fish found in Antarctica. Ice fish have evolved a variety of interesting physiological and biochemical adaptations that allow them to survive in the freezing, ice-laden waters of the Southern Ocean at temperatures that would freeze the blood of other fish.
• They do not have a swim bladder, and they spend much of their time near the ocean floor. To help them survive in the very cold waters, they have antifreeze proteins in their blood and body that keep their cells from freezing.
• Because of the high oxygen content in Antarctic waters, the ice fish are able to survive with lower amounts of hemoglobin, the protein that carries oxygen to the rest of the body, than other fishes. They have a larger volume of clear blood instead and this gives them an unusually ghostly white color, particularly their gills.
• The blood of the ice fish is transparent in colour. They do not have red blood cells. They do not have haemoglobin to transport oxygen. It is an evolutionary adaptation.
• It is not a happy evolution. They absorb oxygen through their skin. They have huge hearts. They were found at a depth of 90 metres to 200 metres.

Question:
Who among the following discovered the mainland of Antarctica in 1820?

1. Fabian von Bellingshausen
2. Ramchran Jee
3. James Cook
4. Mikhail Lazarev

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