Mustelids are a unique type of mammal that can live in various environments, but one member of the mustelid family stands out – the sea otter. While most of its cousins are land-based animals, sea otters are fully aquatic.
Since sea otters have a different habitat from their other otter relatives, it can lead you to wonder: what do sea otters eat?
As you can guess, they probably eat food that they find in and around the water, primarily marine life, but there is much more to their eating habits.
Come join Floofmania as we take a deep dive into these aquatic creatures’ eating habits, favorite foods, and much more!
Are Sea Otters Carnivores, Herbivores, or Omnivores?
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Sea otters are mainly carnivorous creatures since they primarily focus on hunting prey for food.
Despite their cute appearances, sea otters are carnivores just like the rest of the otter family.
However, sea otters can be opportunistic eaters and become omnivores since sea otters are occasionally spotted eating plant food. This is rare, however, and it is doubtful that the sea otter is able to get much nutrition out of the plant material, which definitely cannot replace its carnivore diet.
Do Sea Otters Eat A Lot?
Sea otters do eat a lot of food, and they eat more than their other aquatic otter counterparts.
For instance, the average river otter will eat about 15-20% of its total body weight every day. On the other hand, a sea otter will eat about 25-30% of its weight in food.
As such, you can expect a 100-pound sea otter to eat as much as 25 or 30 pounds of food a day!
Where the sea otter comes from will also determine how much they will consume.
The northern sea otters are bigger than the southern sea otters, so the northern ones will naturally eat more food.
How Often Do Sea Otters Eat?
Sea otters can spend up to 8 hours a day eating, and their eating times are often spread out throughout the day.
While a sea otter can eat whenever it gets the chance, you can expect a sea otter to eat roughly 5-6 times a day.
Why Do Sea Otters Need To Eat So Much?
Sea otters need to eat so much since they need to support their fast metabolisms.
They are known to have “extreme metabolisms” because they do not have an insulating fat layer or blubber, unlike other marine mammals like seals.
Since the waters will be cold, sea otters’ metabolism burns 2.4 to 3.2 times faster than animals of similar sizes to stay warm.
You can expect a sea otter to spend most of its day swimming and hunting. Accompanying this with their fast metabolic rates, sea otters can sustain their energy levels by eating up to a third of their weight in food.
What’s A Sea Otter’s Favorite Food?
A sea otter’s favorite food is anything aquatic, which can vary from fish to hard-shelled crustaceans.
While they do not have an exact favorite food, sea otters usually have prey preferences.
In an otter population in one area, a sea otter will focus on hunting specific prey based on its diving skills.
For example, the best divers will grab clams at the bottom of the water whereas the shallow divers will grab fish that lurk near the top of the water.
Some common foods sea otters are known to eat include:
- Crabs
- Snails
- Urchins
- Abalone
- Clams
- Mussels
- Fish (Northern sea otters mostly)
- Shrimp
Sea Otters Eat Mostly Aquatic Invertebrates
Sea otter diets are heavily based on aquatic invertebrates, which are animals that have hard outer skeletons.
Depending on what is available in their habitat, sea otters will enjoy eating sea urchins, snails, octopi, starfish, barnacles, and even sea cucumbers.
Some common crustaceans are also a favorite for sea otters, such as crabs, shrimp, and lobsters.
Plus, sea otters are known to dine on marine life with extremely tough exteriors, like oysters, mussels, abalones, and scallops.
How Do Sea Otters Get Through The Hard Shells?
Since sea otters eat a lot of hard-shelled animals, they do so by using tools to crack open the shells and reach the animal’s flesh.
Sea otters use their paws to hold firmly onto their food while they crack it open.
They have been observed going to rocks and using them like an anvil by slamming the hard shell against the rock until the shell cracks.
If you have seen sea otters lounging on their backs in the water, they also use this position to crack open their prey!
They rest a rock on their stomach while they float belly-up in the water, and then they smack their prey on the rock to break it open.
What Kind Of Tools Does A Sea Otter Use?
Sea otters use rocks as stone tools. Notably, many sea otters are known to have a favorite rock that they carry with them in their underarm pockets.
However, the sea otter does not need to rely on a rock that they carry since many sea otters will use any big rock that they find along the shoreline.
For example, if the stone is too large for the sea otter to pick up and put on their stomachs, they will just slam their food against the rock.
If a sea otter cannot find a nearby rock, they easily make do by smacking their prey’s shell against boats!
Do Sea Otters Eat Fish?
Sea otters do eat fish, but they will usually go for slow-moving invertebrates and crustaceans that are easier to catch.
However, the Northern sea otters have been spotted eating fish on occasion, which included sardines and smelt.
Do Otters Eat Dead Fish?
Typically, sea otters do not go for dead fish because they will hunt for their prey, so they would first catch a fish and then eat it live.
However, these opportunistic feeders will not turn their noses up at a dead fish if they happen across one while hunting.
Notably, a captive sea otter will eat dead fish since zookeepers usually give them dead fish.
What Meats Do Sea Otters Eat?
Since sea otters are omnivores but primarily carnivores, they will almost always eat meat when given a chance.
Sea otters’ source of protein usually comes from aquatic life, such as crustaceans and the occasional fish.
Will Sea Otters Eat Birds or Small Animals On The Beach?
Sea otters will consume birds or other small animals on the beach when they can catch them!
However, it is more likely to see smaller waterfowl being prey for sea otters since they are easier to drag into the water.
It is also worth noting that the sea otters that have been observed to eat birds were adult males, likely because they are bigger than their female counterparts.
Sea otters are not only limited to catching birds on the beach though since they can catch them in the water!
Typically, sea otters will spot a bird nesting above the water, so they will sneak underwater and drag the bird into the water.
Keep in mind that this is still fairly rare behavior for sea otters and that sea otters would much prefer to eat marine life than birds.
As for small animals, sea otters are opportunistic foodies that will take what they can get whenever they can.
For instance, an otter may go for insects and rodents if they are near one, but it is rare for them to do so.
Sea otters tend to only opt for birds and other small animals as a source of food when they cannot easily hunt for food.
Do Sea Otters Eat Plants Like Kelp and Seaweed?
Sea otters are carnivores that almost exclusively eat animal protein, so eating any kind of plant material is very unlikely.
It is worth noting that they do rely on the growth of seaweed and kelp for survival, because many of their prey’s diets require kelp and seaweed, such as sea urchins and fish.
Moreover, sea otters are considered “helping hands” to the seaweed and kelp growth in areas since overpopulation of prey that eats plant food can annihilate kelp and seaweed growth.
By eating animals like sea urchins, sea otters will effectively keep their population down and allow the kelp and seaweed to thrive.
What Do Sea Otters Eat In The Winter?
As opportunistic hunters, sea otters will eat whatever marine life is available in the winter, which will likely remain the same year-round.
However, it will depend on the area that the sea otter is in since other aquatic life like crustaceans may still be readily available during the colder months.
Author: Allison Marie Dinglasan
Hello! I am Allison, an avid writer for 6 years with a deep interest in animals since I was a child. I grew up on Animal Planet and animal books and often did rescue work for stray and sickly cats, dogs, and birds in my area, which led to over 60 rescues. My future goal is to be a veterinarian to have a more hands-on approach to helping and learning about animals!