As of now, Antarctic krill are “confident” that they will not be completely consumed.
Antarctic krill, also known as Antarctic crustaceans (Antarctic Krill), are considered “the world’s future food reserve.” It is estimated that there are about 30 trillion krill in the oceans, weighing between 50 to 150 million tons. Although more than 300 million tons of Antarctic krill are caught each year, their population remains extremely abundant to sustain a diverse ecosystem in nature.
The habitat of this tiny crustacean is concentrated in the open waters near Antarctica. They are a small species of marine shrimp, measuring no more than 6 cm in length and weighing around 2 grams—smaller than a piece of chalk—with a lifespan of about 5 to 6 years. However, they are distributed across the oceans worldwide. There are over 80 species of Antarctic krill, varying slightly in size and shape, but all share the characteristic of immense population numbers.
It is estimated that there are about 30 trillion Antarctic krill in the oceans.
Few would suspect that this small creature is a crucial link in nourishing the enormous ecosystem of the ocean. They are one of the largest sources of protein in the world.
The largest animals on Earth, such as blue whales and fin whales, consider Antarctic krill to be their primary food source. A blue whale can consume several tons of krill each day, which translates to millions of individual krill. In addition to these colossal whales, seals, penguins, various fish, and squid in the Southern Ocean also eat Antarctic krill, potentially consuming over 250 million tons annually. Humans also catch around 50 million tons of Antarctic krill each year. Consequently, nearly 300 million tons of Antarctic krill vanish each year.
Although Antarctic krill are food for many living creatures, they remain one of the most populous species in the ocean. The primary reason is their incredibly strong reproductive capability.
Each female Antarctic krill can lay between 6,000 and 10,000 eggs at once and can produce multiple batches of eggs during a breeding season. The number of eggs laid by an entire swarm of krill in a breeding season is enormous, nearly uncountable. Antarctic krill reach maturity quickly, becoming capable of reproduction just 24 months after birth.
Antarctic krill feed on phytoplankton in the ocean.
In addition to their strong reproductive capacity, Antarctic krill feed on phytoplankton in the ocean. Phytoplankton are the starting point of the marine food chain. Through the process of photosynthesis, they can capture carbon from carbon dioxide. Thus, phytoplankton are abundant in the sunlit surface waters, where Antarctic krill primarily thrive.
When Antarctic krill spawn, the eggs float in the water due to a lack of adhesive properties in seawater, hatching naturally based on the nutrients in the eggs. The eggs drift aimlessly and gradually sink to depths of hundreds of thousands of meters in the ocean. Here, light is scarce, temperatures are relatively low, and organisms are relatively sparse, allowing the krill eggs to hatch while avoiding many natural predators.
The relatively high survival rate, combined with their nocturnal behavior, allows Antarctic krill during this stage to survive healthily. They then begin to aggregate into large populations and migrate near the surface to feed on phytoplankton. Here, they once again become prey for predators (like whales), and thus the cycle continues.
A large number of Antarctic krill support many other species.
Thanks to their strong reproductive abilities and abundant food supply, as of now, Antarctic krill are “confident” that they will not be completely depleted.
In reality, Earth’s ecosystem is a remarkable balance, with a vast number of Antarctic krill nourishing countless fish, birds, and marine mammals. Without these “predators,” this crustacean species would proliferate uncontrollably, thereby affecting the balance of the marine ecosystem.
Currently, due to human fishing activities and climate change, the number of whales has significantly decreased, which allows the population of Antarctic krill to remain very large.
