The Sea Otter – Aries

Image of Sea Otter

General facts about Sea Otters.

If you imagine an Otter, you might find yourself picturing a birthday card where they’re smiling at you with googly eyes. Or perhaps you see an advertisement for a waterpark. It’s no secret that these animals are widely known for their uplifting charms. Otters are loved worldwide for their playful, affectionate, and cuddly demeanour. The word Otter is derived from “Otor”, which dates back to the Indo-European era meaning “Aquatic Animal”. These creatures thrive in their aquatic surroundings: from playing on self-made waterslides to sunbathing on rocks. Otters exhibit strong social behaviour, with many living in large groups called “rafts”. It’s easy to see why such innocent animals would garner positive attention, and even easier to see why they are frequently preyed upon.

The Otter, also known as Lutrinae, has been in existence for 20 million years. During this time, they have adapted many forms to suit their changing surroundings. They belong to the family Mustelidae, which includes 13 species of Otter, Badgers, Weasels, Ferrets, Minks, and Wolverines.

Sea Otters have lost 50% of their population since the 1970s. But they are not the only Otter species to face extinction. Almost all the Otters range from threatened to endangered. The Otters facing the highest risks are the Hairy Nosed Otter, The Marine Otter, and the South American River Otter. Today we will be focusing on the well-being of the Sea Otter, and how their environment has changed over the decades.


Also known as Enhydra Lutris, the Sea Otter is a newcomer to the Ocean. Until about 7 million years ago, Otters were limited to freshwater but have since evolved to a wider range of oceans and seas. The Sea Otter may weigh a lot for its size, but it is the second smallest marine mammal. These mammals do not have blubber like Seals and Sea-lions. Instead, they have dense fur which insulates them from cold temperatures. Sea Otters have very rounded features, which help them swim effectively. When they dive, the ears and nostrils automatically close to protect them from water-logging.

You will find these friendly animals close to the shoreline in estuaries. They cannot dive very deep compared to fish, about 100m, which is still deep! Therefore, they favour shallow waters. Sea Otters spend a lot of their lives in water, surrounded by oceanic vegetation like seaweed and sea kelp forests.

Image of Sea Otter

The Sea Otter: Out of the Blue!

What is the size, weight & colour of the Sea Otter?

Sea Otters are the heaviest of all Otters. Adult females can range 1-1.5m, weighing up to 45kgs. Males are significantly larger than females and range from 1-1.8m long, weighing up to 60kgs. The Otter’s tail makes up for two thirds of its body length.

These mammals have a wide range of fur colours. In their younger years, their fur is a dark brownish-black. As they get older, much like humans, they develop grey hairs. A mature Sea Otter will have a white face and head.

Image of Sea Otter

What type of vision does the Sea Otter have, and what sounds do they make?

Sea Otters have tremendous sight out of the water, but they have to rely on their whiskers to hunt in the ocean. Their whiskers can sense vibrations in the current and help detect when prey is close.

Are there any special or unique physical attributes?

Hair, Hair and more Hair! For comparison, the average human scalp houses 700 hairs per square inch. The Sea Otter has over 850,000-1,000,000 hairs per square inch. This is the finest fur of any mammal in existence, and Sea Otters have the thickest fur in the animal kingdom. These creatures rely on this fur to regulate their body temperature and act as an impenetrable force against water. There are two layers of fur on a Sea Otter, the undercoat and the overcoat, both working to trap air and keep them dry.

If the Sea Otter’s fur becomes oily from contaminated water, it is difficult to remove. As a result, you will see Otters spending much of their day cleaning their fur of foreign substances.

Another special feature of this mammal is the loose patch of skin under its forearms. These pouches are used to store rocks and food. When at the surface the Sea Otter will use a rock to break and open the shellfish, so they always need one or two handy!

Image of Sea Otter

How fast is the Sea Otter?

Sea Otters don’t swim very fast, but they are very agile. Our friends swim with their hind legs and can reach up to 8kmh.

How do they hunt, and what do they eat?

Sea otters are avid foragers and rely on their front paws and have an acute sense of smell. Their whiskers are sensitive, and they use them to locate their prey. Our friends have retractable claws, which aid them in grabbing moving fish. In order to stay warm and energized for playtime, the Sea Otter must consume 25-30% of their body weight in fish every day! Their high metabolic rate is sustained by small fish, frogs, shellfish, small mammals, and birds. Shellfish are their favourite food, and they will carry small rocks in their sleeves to crack them open. Sometimes they will dive as deep at 80m to catch prey. In order to eat their shellfish, they have flat, rounded molars designed to grind and crush hard materials. Sea Otters have evolved over millions of years to hunt fish and sea creatures, while regular Otters live on land and consume smaller mammals.

Who are their natural enemies?

The Sea Otter is a tertiary consumer. It needs to be on the lookout for apex predators such as Great White Sharks, Killer Whales, Bears, and Eagles.

The fur trade has also had a significant impact on their populations, as the Sea Otters fur is prized for its waterproof abilities. While this is illegal, human fur trading has diminished most of the Otter populations in areas like Japan and Mexico. There were once about 1 million Sea Otters in our oceans, but due to this hunting, the worldwide count had been driven down to only approximately 2,000. Today their populations have increased to 106,000, and the effort continues to preserve their numbers.

Where do they live?

Sea Otters can be found south of Russia, and then span the Pacific Ocean scaling the entire west coast of North America, from Alaska to Mexico. This mammal will not stray far from the coastline, as they rely on coastal vegetation for resting. Alaska has 75% of the world’s population of Sea Otters (72,000), as their numbers have diminished significantly elsewhere. A key factor in Otter communities is the ability to live among their species in “rafts”. The largest raft community ever recorded housed 2,000 Otters!

Image of Sea Otter habitat

What are their migration habits and routes?

Unlike many sea creatures, the Sea Otter does not migrate. They stay relatively close to where they are born, and only leave in search of food. Some of these Otters have been known to travel a few miles down the coastline to find mates but are usually found within their raft communities. This stagnant lifestyle gives them the advantage of avoiding predators in unknown waters.

Image of Sea Otter

All about Reproduction.

Sea Otters become sexually mature slowly, with females taking 3 years, and males taking 6 years. Unlike many animals, the female can only bear one pup per pregnancy. This pregnancy lasts between 5 and 8 months, and their pups will remain dependent on their parents for 12 months. A newborn pup weighs 2.2kgs and measures at about 25cm. There is no distinct mating time for these mammals, as it occurs all year round in all seasons.

Life Span.

Our friends have the ability to live for 25 years! However, due to many environmental factors, the average Sea Otter today will only live to be 12 years. This is primarily due to water contamination from human waste.


In Japanese mythology, Otters are cunning foxes. These stories include Otters luring men to their deaths by shapeshifting into women. In Korean mythology, it is said that the sight of an Otter will attract storm clouds into your life. It is a mystery how such cheerful and playful creatures have been used to depict mischief and bad luck.

What threats do the Sea Otters face?

Apart from natural predators, the Sea Otter’s largest threat is humans. Humans have a significant impact on the quality of marine life. Oil spills on small and large scales have been detrimental to the health of these Otters because they cannot remove oil from their fur. When the oil is soaked into the Sea Otter’s fur: insulating air is lost and they cannot stay warm. In an attempt to clean the oil from their fur the Otters mostly die from organ failure.

In addition to their environments being polluted, humans also hunt Otters for their fur. They nearly went extinct in the 19th century because of the fur trade in North America. Since then strict measures have been implemented to stop the Otter fur trade. Their numbers have been growing, but pollution and illegal fur trade still threaten the Sea Otter. Additionally, shellfish hunters lay traps for Otters because they are hunting the fish they are trying to catch. In these cases, the Otter becomes entangled and drowns.

Why is the Sea Otter endangered?

Female Sea Otters can only give birth to one pup at a time, approximately once a year. This makes for slow population growth. It can also take male Otters half of their life to reach sexual maturation, which makes for a slow-moving mating environment. Coupled with this fact, poor water conditions do not provide the Otter with the best environment to thrive in.

New threats have been revealed on top of this slow population growth: 40% of Sea Otter deaths are caused by parasites. These bugs come from runoff water directly entering the Otters feeding ground. Pollution from humans has both an external and internal impact on the creatures. While it is possible for Otters to evade physical danger, it is nearly impossible for them to avoid infected water.

Endangered Ranking – IUCN.

The Sea Otter is on the IUCN (International Union for Conservation of Nature) Red List of threatened species. While Sea Otters were once nearly extinct, their populations have increased. Sea Otters are currently classified as endangered in many areas, especially the west coast of the USA. Today the largest threat to the Sea Otter is their polluted habitat. Many steps are being made by the IUCN to protect Otters in their habitats so they can live long, healthy lives.

Why should you care?

Sea Otters play an important role in maintaining kelp forests along coastlines. This indirectly affects humans because the kelp forests aid in reducing carbon dioxide. The kelp is also an important hiding and spawning ground for other fish. Without Sea Otters to hunt small fish and crustaceans, the kelp would be eaten away and deteriorate. All animals play an important role within their habitats through the food chain. Sea Otters are sentinel creatures because the health of their population is reflected in their surroundings.

What can you do to help?

  1. Ethical Consumption: Shellfisheries are responsible for trapping and killing many Sea Otters in pursuit of financial gain. Take time to research ethical Shellfisheries in your area, or cut down on your consumption of Shellfish.
  1. Spread the word! Talk to family members and friends about what they’re doing to help the cause. Inform people on ways they can help protect the Sea Otter and its habitat. There are many charities that aim to protect coastal waters and save Otters from oil spills.
  1. Get Involved: Lastly, spend time signing petitions and getting involved in online spaces. If you can, take part in coastal cleanups to keep Otter habitats litter-free.

If there is a public demand for change, then change will come. With everyone’s help, we can create new standards for the ocean and all of its inhabitants! With safer oceans, we will continue to see the Sea Otter populations stabilize.

Bethany MacDonald

Bethany MacDonald

Bethany MacDonald has contributed articles since 2020. As their Blog Lead, she specialises in informative pieces on culture, education, and language learning

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