When it comes to high-protein foods, many people first think of beef, eggs, milk, etc.
However, there is such an animal with a protein content of up to 20%, most people are not familiar with it, it is antarctic krill.
Antarctic krill has strong reproductive ability and extremely rich reserves, and in the context of increasingly scarce fishery resources, it may become the largest protein resource bank for human beings in the future, so it is called "the last animal protein source of mankind".
However, Antarctic krill has not become mainstream so far, and even rarely appears on the dinner table, why is this? Let's take a look.
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1
What is Antarctic Krill? What are the features?
What people usually call Antarctic krill, the scientific name is Uphausia superba, alias squash or Antarctic krill, is a krill family, krill shrimp.
Antarctic krill is not actually a shrimp, it is a marine creature that lives in Antarctic waters. Antarctic krill looks like a small shrimp, growing mini cute, 3 to 5 cm long, and the largest species is about 7 cm long. Since their food is mainly phytoplankton, the body is transparent, and the green digestive glands inside can be seen from its shell. Another feature of Antarctic krill is that they carry biological fluorescent organs, which emit light. But the fluorescence is not as small as small fireflies, and it has been shown that the light they emit is as far as 510 nanometers, and the brightness can even be compared with the flashlight.
Can you imagine where these luminous organs are distributed?
There is a pair on the eye stem, a pair in the position of the second to seventh thoracic foot, and another on the abdominal patch. They emit yellow-green light every 2-3 seconds, but the function of these lights cannot be determined by current research. Antarctic krill is still very tenacious, especially extremely resistant to hunger. One of their special skills is to use the way of shelling growth to carry out negative growth when surviving the harsh and long winter in Antarctica. Experiments have shown that they can live for more than 200 days without eating. Among the small invertebrate species, they can live for about 6 years, which can be said to be relatively long-lived.
These little creatures may know that unity is strength, so living in groups is their preferred way of life. We can see their life trajectory at a shallow surface of 50 meters, and the main formation of clusters is also within 200 meters of the surface, but the density will be different depending on the sea and the season.
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Antarctic krill are a key species in the Antarctic ecosystem, and some studies say that they are perhaps the most successful animal species on the planet, and the amount of resources makes Antarctica a granary in the sea.
2
Is Antarctic krill the "last source of animal protein for humans"? Why are there so many reserves?
In the 2015 edition of the IUCN Red List of Threatened Species, Antarctic krill are classified as non-threatened (LC) species. According to the current biological reserves, some people have praised the Southern Ocean as a "human food storehouse".
The demand for Antarctic krill is rising year by year in many fishing countries, such as Norway, which harvests up to 400,000 tons of krill from Antarctic waters every year.
According to relevant scientific surveys, antarctic krill reserves are about 400-600 million tons. Biologists estimate that if the catch does not exceed 50 million tons per year, Antarctic krill will still grow and develop normally.
Antarctic krill resources are called "offshore gold mines", why are the reserves so abundant?
First, krill have strong fecundity and a large number. Antarctic krill lay high eggs, up to 100,000 eggs at a time, usually in deep water of 2-3 km, hatching and then swimming into shallow seas. When they swim to the shallow seas where they live, they grow up.
Second, krill have strong living ability and strong vitality. Under threat from blue whales, fin whales, penguins, seals and fish, resources remain enormous.
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3
What are the nutrients of Antarctic krill? How much is eaten each year?
The nutritional content of Antarctic krill is slowly discovered by humans, high protein, low fat, and krill mineral content, containing a variety of active substances, such as protein digestive enzymes, cytotoidin amino acids and so on. A large number of Antarctic krill are eaten by large marine organisms every year. For example, a baleen whale can swallow about 43 million tons of krill a year, and seals can swallow 63-130 million tons of krill. Human catches are far less than these large carnivorous creatures. In the beginning, most of the antarctic krill harvested by humans was used to produce feed and bait. Later studies found that Antarctic krill has a high content of chitin, astaxanthin and krill oil, and is easy to extract, so it is used to make medicines and nutritional products.
4
Why hasn't it become a national food yet?
Antarctic krill is nutritious and huge, but why is it so hard to see on our tables? Even many people have not eaten?
After the Antarctic krill is caught, it needs to be processed quickly, otherwise the fluorine component in their body will rise rapidly and the taste will be difficult to guarantee. Moreover, this small creature is difficult to appear in its original appearance after processing.
In the ocean, life, large and small, is important for the balance of marine ecosystems. Studies have shown that Antarctic krill are excreted through feces, fixing large amounts of carbon to the seafloor and providing a "biological pump" for ecosystems.
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As the demand for protein increases, Antarctic krill is also gradually becoming a fishing target. But climate change has a huge impact on the reproduction and survival of Antarctic krill. Although the current antarctic krill resource reserves are relatively high, if the fishing industry develops in disorder, it will eventually lead to a lack of resources, endanger the survival of other Antarctic animals, and bring catastrophic consequences to the fragile ecosystem of Antarctica.
At present, the international community is also paying attention to the effective, sustainable use and healthy maintenance of resources of Antarctic krill, and has stipulated the annual fishing limit in the Antarctic and Atlantic regions: fishing is prohibited when it reaches 625,000 tons!
Focus on the ecological balance, pay attention to the key species of the Antarctic ecosystem - krill! Scientific protection and rational development.
(Popular Science China)