Sea otters are cute, furry critters found in many zoos across America. You may have gone and seen some yourself. But have you ever wondered how long sea otters live in the wild?
Sea otters live, on average, for around 10 to 15 years. A sea otter can live up to 20 years in the wild. Female sea otters, on average, live longer than male sea otters. Certain factors disrupt the sea otter’s lives, and it’s thought they could live longer without them. This includes pollution, construction, and poaching.
You may be interested that female sea otters live longer than male otters. Keep reading to find out why this is and more.
Our article will tell you everything about a sea otter’s lifespan. By the end of this article, you’ll know long they live, how they live that long, and why.
Let’s dive in.
How long do sea otters live in the wild?
A sea otter’s lifespan is around 15 years on average. The longest a sea otter has lived is 28 years in an aquarium.
A biologist can determine a sea otter’s age by examining the sea otter’s tooth eruption, skull changes, and weight. Research has shown that these are the most reliable techniques for age examination.
Sea otters give birth to 1 or 2 pups and breed every two years. The survival rate of these pups can range from 53% to 88%.
There are many reasons a sea otter’s lifespan is how it is. It can be cut short for many reasons, and we’ll review those now.
Why do sea otters die?
1. Poaching
Poached for their fur, it’s one of the main reasons sea otter populations have declined. This is most common around Asia, as there are laws to protect sea otters elsewhere.
In Asia, illegal fur trades run in India, Nepal, and Bangladesh. In China, the demand for sea otter fur is high.
Korea, Russia, and Japan also highly demand sea otter fur. This is for the same reasons as China, and fur clothing and items are popular in these countries,
Sea otters have the thickest fur in the world, which makes their fur desirable. Their fur is dense and durable, which makes them great for thick winter clothes.
In Asia, sea otters get poached for their meat as well. You may find otter meat on the menu in many exotic restaurants.
People use their body parts alongside their meat for multiple reasons and believe they have therapeutic effects. They also use otter blood to treat epilepsy and their skin to help women during pregnancy.
They are also kept as domesticated pets in many Asian countries. Reports have said that the origins of these sea otters are from Southeast Asia.
Live otter trades are prominent in Malaysia, Japan, Indonesia, and Thailand. Most of these businesses can be found on the internet, with many websites based on selling live otters.
2. Predation
Sea otters have many natural predators, including killer whales and sharks. Other predators include coyotes, bears, eagles, and sea lions.
Studies in Alaska have shown that orcas are eating more and more sea otters. This is caused by the decline of their usual predators, seals, and sea lions.
The killer whales learned to swim on their backs to hunt the sea otters below them. They then swim up, grab the sea otter, and eat it whole.
Sharks prefer fatty, calorie-dense prey like seals and sea lions but have recently been shown to be experimenting with sea otters. They take bites of the sea otter, only to be left with fur instead of blubber.
These shark bites can be fatal for the sea otter, as it opens them up to severe infections and injuries. Sea otter death rates have been increasing in California due to the increase in great white shark populations.
Bald eagles eat Alaskan sea otter pups when the adults go to scavenge for food. They swoop down, grab them with their sharp claws, and eat them in a different location.
The decline in sea otter populations has affected bald eagles. Their diets and hunting methods have changed, and they have been eating more seabirds.
3. Fisheries
Fisheries have impacted sea otter populations by trapping and injuring them. Many sea otter deaths have been related to ghost gear left behind by fisheries.
This ghost gear has caught and drowned sea otters and decreased populations worldwide. The most dangerous types of ghost equipment include fishing pots and traps.
A study in 2011 showed that sea otters attempted to enter the traps to find food. The traps used included finfish traps, lobster traps, and mock Dungeness crab traps.
The study concluded that the opens for these traps were large enough to trap sea otters. Even if observers were protecting them, many deaths would go unnoticed.
4. Pollution
Sea otters have succumbed to pollution for years, with oil spills most damaging to their populations. The IUCN classifies oil pollution as a significant threat to sea otters.
As sea otters need their fur for many reasons like insulation, oil is a significant threat to sea otters as it soaks their fur. This means they can’t keep warm, and they can die from hypothermia.
The oil sticks in their fur, and they inhale the fumes whilst swimming or grooming. Their lungs, liver, and kidneys become damaged due to the toxic fumes.
In March 1989, The Exxon Valdez oil spill left thousands of sea otters dead. The Prince William Sound is still affected by the fumes and still affects the sea otters.
As sea otters have small populations living across different states, an oil spill could devastate and wipe out these populations. Measures should be implemented to prevent oil spills, alongside rescue plans for the affected populations.
Although some have advocated not to increase sea otter populations as they decrease shellfish resources. In some cases, fishermen have illegally killed sea otters because of this.
5. Disease
A parasite called Toxoplasma gondii has infected many of California’s wild sea otters. This is a brain infection that can be fatal to sea otters.
But, the fatality can vary between sea otters. It depends on what strand of the parasite they contract.
The fatal strands can be traced back to bobcats and feral domestic cats. These cats can be found in watersheds on the coast of California.
Another disease that affects sea otters is cardiomyopathy, a heart disease. These effects can occur when the sea otter becomes exposed to domoic acid.
Marine algae bloom releases domoic acid known as red tides. This toxin can cause seizures and tremors in animals exposed to it.
Sea otters whose diet consists of crabs and clams, which can contain large amounts of domoic acid, were twice as likely to die from cardiomyopathy. Otters with Toxoplasma gondii also are at risk of this heart disease.
It has been discovered that a virus has been killing sea otters in Alaska. The name of the virus is phocine distemper virus, similar to the canine distemper virus.
This virus is spread between marine animals due to abrupt migration patterns. This is due to climate change and is become an emerging health issue for sea otters.
In conclusion
On average, sea otters can live 10 to 15 years. Although they have a pretty long lifespan, some factors can affect this.
Poaching is a massive problem in Asia and other continents. Poached for their meat, fur, and other body parts contributes to the decline of sea otters.
Predation is also another factor that reduces the lifespan of sea otters. Killer whales have been overhunting sea otters to compensate for the decline of seals and sea lions.
Fisheries are also contributing to the decline of sea otter populations. Caught in left behind equipment, fisheries contribute to the death of sea otters with ghost gear.
Oil pollution is a significant threat to sea otters and severely harms populations in areas where oil spills have occurred. Oil harms sea otters by damaging their fur and internal organs.
Many diseases can affect sea otters. This includes toxoplasma gondii, cardiomyopathy, and phocine distemper virus.
