The last source of animal protein for humans! The quantity is as high as hundreds of millions of tons, why hasn’t it become a national delicacy?

Expert of this article: Liu Yadan, former assistant secretary-general/researcher of China Fisheries Society, national chief scientific communication expert

This article was reviewed by Zhu Guoping, Professor of Shanghai Ocean University

When it comes to high-protein foods, many people first think of beef, eggs, milk, etc.

However, there is an animal whose protein content is as high as 20%, but most people are not familiar with it. It is Antarctic krill.

Antarctic krill has a strong reproductive capacity and extremely abundant reserves. Against the backdrop of increasingly scarce fishery resources, it may become the largest protein resource for humanity in the future, so it is called "humanity's last source of animal protein."

However, Antarctic krill has not yet become mainstream and rarely appears on the table. Why is this? Let's find out.

Copyright image, no permission to reprint

1

What kind of shrimp is Antarctic krill? What are its characteristics?

What people commonly call Antarctic krill is scientifically named Euphausia superba, also known as giant krill or Antarctic krill. It belongs to the Euphausiaceae family and the Euphausia genus.

Antarctic krill is actually not shrimp, but a kind of marine creature that lives in Antarctic waters.

Antarctic krill look like small shrimps, and are cute and mini, 3 to 5 cm long, with the largest species being about 7 cm long. Since their food is mainly phytoplankton, their bodies are transparent, and the green digestive glands can be seen from their shells.

Another feature of Antarctic krill is that they have bioluminescent organs that can emit light. However, the fluorescence is not as small as that of fireflies. According to research, the light they emit is far away, and the brightness is even comparable to that of a flashlight.

Can you imagine where these light organs are located?

There is a pair on the eyestalk, a pair on the second to seventh thoracic legs, and one on the ventral plate. They can emit yellow-green light every 2-3 seconds, but current research has not yet determined the function of these lights.

Antarctic krill are very strong and can resist starvation. One of their unique skills is to survive the harsh and long winter in Antarctica by molting and growing negatively. Experiments have shown that they can live for more than 200 days without eating. Among small invertebrates, they can live for about 6 years, which is relatively long-lived.

These small creatures may know that unity is strength, so living in groups is their preferred lifestyle. We can see their life tracks in the surface layer shallower than 50 meters, and the main clusters are also formed within 200 meters of the surface, but the density will vary in different sea areas and seasons.

Copyright image, no permission to reprint

Antarctic krill are a key species in the Antarctic ecosystem. Some studies have also said that they may be the most successful animal species on Earth. The huge amount of resources makes Antarctica a granary of the sea.

2

Antarctic krill is "the last source of animal protein for mankind"? Why are there so many reserves?

In the 2015 edition of the IUCN Red List of Threatened Species, Antarctic krill is classified as a species of Least Concern (LC). Based on the current biological reserves, some people call the Southern Ocean the "food bank for mankind."

The demand for Antarctic krill from many fishing countries is increasing year by year. For example, Norway catches up to 400,000 tons of krill from the Antarctic waters every year.

According to relevant scientific surveys, the reserves of Antarctic krill are about 400-600 million tons. Biologists estimate that if the catch does not exceed 50 million tons per year, Antarctic krill will continue to grow and develop normally.

Antarctic krill resources are called "offshore gold mines", why are the reserves so abundant?

First, krill have strong reproductive capacity and large numbers. Antarctic krill have a high spawning rate, with up to 100,000 eggs laid at a time. These eggs are usually in deep waters of 2-3 kilometers, and after hatching, they swim to shallow seas. When they swim to the shallow seas where they live, they grow up.

Second, krill have strong vitality and are very resilient. Despite the threats from blue whales, fin whales, penguins, seals and fish, their resources are still huge.

Copyright image, no permission to reprint

3

What nutrients does Antarctic krill contain? How much is eaten each year?

The nutritional value of Antarctic krill has been gradually discovered by humans. It is high in protein and low in fat. Krill is also high in minerals and contains a variety of active substances, such as protein-digesting enzymes, mycobacterial amino acids, etc.

Every year, a large amount of Antarctic krill is eaten by large marine organisms. For example, baleen whales on Earth can swallow about 43 million tons of krill a year, and seals can eat 63-130 million tons of krill.

Humans cannot catch as many krill as these large carnivorous creatures. In the beginning, most of the krill caught by humans were used to produce feed and bait. Later, studies found that the chitosan, astaxanthin and krill oil in Antarctic krill are very high and easy to extract, so they are used to make medicines and nutritional supplements.

4

Why hasn’t it become a national delicacy yet?

Antarctic krill is rich in nutrients and has huge reserves, but why is it so hard to see it on our tables? Even many people have never eaten it?

After Antarctic krill are caught, they need to be processed quickly, otherwise the fluorine content in their bodies will increase rapidly and the taste will be difficult to guarantee. Moreover, it is difficult for such a small creature to appear in its original appearance after processing.

In the ocean, all organisms, big and small, are important to the balance of the marine ecosystem. Studies have shown that Antarctic krill excrete large amounts of carbon to the seafloor, providing a "biological pump" for the ecosystem.

Copyright image, no permission to reprint

As human demand for protein increases, Antarctic krill has gradually become a target of fishing. However, climate change has a huge impact on the reproduction and survival of Antarctic krill.

Although the current reserves of Antarctic krill resources are relatively high, if the fishing industry develops in an unorderly manner, it will eventually lead to resource scarcity, endanger the survival of other Antarctic animals, and bring catastrophic consequences to Antarctica's fragile ecosystem.

Currently, the international community is also paying attention to the effective and sustainable use of Antarctic krill and the healthy maintenance of resources, and has set annual fishing limits for the Antarctic and Atlantic regions: fishing is prohibited once it reaches 625,000 tons!

Pay attention to the ecological balance and the key species of the Antarctic ecosystem - krill! Protect scientifically and develop rationally.

The watermarked images and cover images in this article are from the copyright gallery, and the image content is not authorized for reprinting