Do Otters Eat Fish? (Here’s What They Do!)

All otter species live near water, enjoy similar diets, and have extremely high metabolisms that require them to eat large quantities of food each day.

Are fish part of their diet?

Both sea otters and freshwater or river otters eat many types of fish and crustaceans; these food sources can make up as much as 90% of an otter’s diet. Otters are such efficient hunters that they can completely eliminate fish populations from ponds! Aside from fish, river otters also eat small reptiles, amphibians, birds, and mammals on occasion.

Continue reading to discover the specific types of fish, crustaceans, and other animals eaten by otters. We’ll also discuss how otters can eat all of the fish in a pond and methods to stop them.

Are Fish Part Of An Otter’s Diet?

Fish make up a huge portion of otters’ meals and can account for as much as 90% of their diet. Both river otters and sea otters eat large quantities of fish on a daily basis. 

River otters consume 15% to 20% of their body weight every day, and sea otters eat even more, at 25% to 30% of their weight. 

The reason otters eat so much is that they have a very high metabolic rate, which is important to regulate their body temperature. They also spend around 60% of their time hunting and need enough food to fuel them as they hunt.

Sea Otters

Sea otters like to eat numerous kinds of marine prey, including:

  • Shrimp
  • Shellfish
  • Eels
  • Sea urchins
  • Crabs
  • Clams
  • Abalones
  • Snails
  • Mussels
  • Slow-moving fish
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Not all sea otters have exactly the same diet. Each individual otter has its own preferences and favorite food sources.

Sea otters procure their meals by diving to the ocean floor to catch prey with their front paws. Then, they bring their capture to the surface of the water, where they lie on their backs and eat while balancing their meal on their chests.

Sometimes, sea otters use flat rocks as tools to break open the shells of mollusks and crustaceans. They are the only type of marine mammal that uses stone tools.

River Otters

River otters enjoy a variety of fish and crustaceans, including the following:

  • Mussels
  • Carp
  • Crabs
  • Crayfish
  • Sunfish
  • Suckers
  • Minnows
  • Snails
  • Sculpin
  • Salmon
  • Trout
  • Stickleback
  • Eels

This type of otter is willing to travel up to 20 miles if they can’t find enough food. River otters generally prefer to eat large, slow-moving fish because they provide more energy and are easier to capture. 

River otters use their vibrissae (also known as whiskers) to pick up on the movement of prey in water. They catch their prey using their teeth.

Aside from fish and crustaceans, river otters eat amphibians like frogs, small mammals, and coots, which are a type of waterbird. They also consume aquatic plants and roots, birds and bird eggs, turtles, rabbits, and muskrats. 

Other parts of their diet are worms, chicks, beetles, fish eggs, snakes and snake eggs, and immature beavers.


The vast majority of otters need consistent access to fresh water. This is particularly true for freshwater otters.

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However, sea otters have large kidneys that allow them to drink seawater and extract fresh water from it.

Will Otters Eat All Of The Fish In A Pond?

Photo: Dean Croshere / Flickr / CC BY 2.0

Otters are so effective at poaching and fishing that they can completely eliminate fish populations from a pond within a short period of time.

Considering their predatory efficiency and need to eat large amounts of food each day, this isn’t too surprising!

Slow-moving domestic fish, like koi and carp, make very easy prey for otters, especially if they live in small ponds.

Farm pond owners and anglers are often frustrated when they find that otters have discovered their ponds and wiped out their fish populations.

How To Prevent Otters From Eating The Fish In Your Pond

If otters have discovered your pond, there are some measures you can take to eradicate them.

Install Physical Barriers

A fence can be your first line of defense in keeping otters away from your pond. Make sure that there aren’t any gaps, since otters can slip through even small ones of under 0.5 of an inch. One-strand, low-voltage electric fencing is an option.

Other physical barrier options include netting, covers, and heavy-gauge mesh placed over the surface of the pond.

Add Fish Shelters

A simple way to protect your fish population from otters is to add fish shelters to your pond.

Be sure to choose shelters that are large enough for your fish to fit into, but too small for otters to enter.

Use Electronic Deterrents

Outdoor lights, especially motion-sensing variations, can warn you when otters arrive at your pond.

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Motion-sensing cameras can serve the same purpose.

Purchase Predatory Decoys

Decoy wolves, bobcats, or coyotes may scare otters away from your pond. However, otters are very intelligent and may realize that the decoys don’t pose a real threat.

For best results, try using decoys in addition to other methods on this list.

Hire A Professional To Relocate The Otters

In some areas, relocating wildlife is illegal. If it’s legal to relocate otters where you live, we recommend using a humane trap or hiring a professional to do so. 

Still, avoid relocating otters if you can. Relocation results in severe stress and potential endangerment once the otters arrive in a new, unfamiliar location. 

When they’re relocated, the odds of otters struggling to find resources or suffering attacks from other animals who have claimed the area increase quite a bit.


Freshwater and sea otters have a diet composed of up to 90% fish and crustaceans. Other parts of a river otter’s diet include small mammals, amphibians, reptiles, birds, insects, and aquatic plants.

Otters are so effective at poaching and fishing that they can eliminate entire fish populations from ponds, especially slow-moving fish like koi and carp. 

There are several methods that can prevent otters from gaining access to ponds and eating the fish. These include installing physical barriers like fences and heavy-gauge mesh covers, adding fish shelters to the pond, and using electronic deterrents and predator decoys.

If it’s legal in the area, otter relocation is also an option, although it has negative impacts on the otters.

James Ball

James has had a lifelong passion for animals and nature, tracing back to his childhood where he first began fostering intimate knowledge and connection with pet frogs and snakes. He has since honed this interest into a career as a trained Wildlife Biologist, specializing in Biogeography, sustainability and conservation. In addition to his professional pursuits, James maintains an active lifestyle, regularly indulging in outdoor activities such as hiking, and musical pursuits like playing piano and swimming.

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