It’s Such A Thrill to Learn Everything About Krill

Can you guess the sea animals that are the size of a paper clip, yet can be seen from space? The krill! Not when it’s on its own, of course, but when it swims in a big swarm!

Krill usually live together and swim in enormous swarms which get so dense that they can be viewed high up above Earth’s atmosphere. Sometimes, when they swim close to the ocean’s surface, they make the water look like it has a pinkish-red shade.

With 85 different species in all the oceans around the world, krill are small shrimp-like crustaceans—and incredible creatures! Their average size is about 3.5cm in length and can reach double that length during periods of food abundance.

They eat phytoplankton, copepods, zooplankton, and algae—all of which are pretty much seasonal food options (check our article about springtime in the ocean). Due to the different seasons in the ocean and the different food availability, krill experience periods of intense feeding followed by continuous starvation. This causes their bodies to grow and shrink numerous times throughout their life.

To accommodate these changes in size, krill shed their shell every 13-20 days to make room for their extra big bodies—or to fit into their smaller ones. That’s why it’s impossible to tell the age of a krill by the size of its body. But you can guess by the size of its…eyes! The bigger the krill’s black eyes, the older it is!

Even though krill are so small, they can dive deep down to depths of 3000 meters to lay their eggs directly in open water. Female krill can lay up to 10,000 eggs per day, which explains why there are so many krill in the world!

They make up a large percentage of the ocean’s biomass, and they also play an important role in the global food chain. As they feed on phytoplankton, they convert primary sea plants into a food source for those higher up on the food chain that can’t eat such small organisms.

Krill are the main food of many sea species including salmon, penguins, and blue whales! Blue whales feed almost exclusively on krill and need to eat a huge number—about 4 tons of those tiny creatures a day. That’s about the weight of a fully-grown hippopotamus. It’s no wonder that in Norwegian, krill means ‘whale food’!

Highly abundant and rich in nutritive qualities such as protein, vitamin A, and omega-3 fatty acids, krill have been harvested for human consumption for centuries. In addition to being nutritious, they are also very delicious!

Salmon also love eating krill! At Kvaroy Arctic, we make sure to add krill to our salmon feed because of its bountiful and valuable nutrients. We know that what our salmon eats is important for its health and for the health of the people it feeds.

Krill contains a good range of amino acids that help salmon to build healthy tissues. It is also worth noting that krill have something that salmon have a limited ability to produce on their own—it is a vitamin-like nutrient called phosphatidyl choline that is essential for normal cell function.

Thanks to krill’s richness in omega-3s, vitamins, and all of the other vitamins and minerals, salmon nourished with krill in their feed make for better food for us humans!