Otter luck: Sea otter populations dwindling dramatically and great white sharks may be to blame

By
Daily Mail Reporter

Last updated at 9:25 PM on 18th February 2012

They’ve had to survive famine, disease, and clashes with boats.

But shark attacks may be to blame for the significant decline in sea otter populations around the California coast.

Scientists are mystified at the recent number – up to 30 per cent of dead otters found along the coast have shark bites, up from ten per cent in the mid-1990s.

Dwindling populations: California sea otters, like these in Monterey Bay, are dropping in numbers

Dwindling populations: California sea otters, like these in Monterey Bay, are dropping in numbers

Supper time: The biggest culprit is the great white shark

Supper time: The biggest culprit is the great white shark

Mercury News reports that in 2011, 70 sea otters washed up on shore, showing tell-tale signs of a shark attack.

Some otter carcases even had shark teeth embedded in their skin. 

Tim Tinker, a wildlife biologist with the U.S. Geological survey told the website that one popular theory is that sharks are mistaking otters as sea lions and elephant seals – their primary prey.

Those creatures, she said, have increased in population over the last decade and have moved to other locations.

Great whites have never been seen eating a whole otter for food, Mercury News reported, nor have they been known to actively hunt otters.

Mistaken identity: Some scientists believe the sharks don't realise they're attacking otters - instead thinking it's their normal food source of seals and sea lions

Mistaken identity: Some scientists believe the sharks don’t realise they’re attacking otters – instead thinking it’s their normal food source of seals and sea lions

Embedded truth: Some dead otters have been found with shark teeth stuck in their bodies

Embedded truth: Some dead otters have been found with shark teeth stuck in their bodies

Last year, a study revealed that there were about 219 great white sharks off the coast of California, fewer than originally thought.

SEA OTTER FAST FACTS

Sea otter

Sea otters are the heaviest members of the weasel family, weighing between 35 to 100lbs. However, they are the second smallest marine mammal. Its coat is the densest in the animal kingdom and allows them to stay warm despite frigid water temperatures. They live on a diet of mussels, clams, crabs, and urchins. In recent years, fur trade and oil spills have whittled away otter populations.

Source: defenders.org

Stanford University marine biology professor Barbara Block told the News that other sharks such as sevengills and makos could be the culprits of the attacks.

She added: ‘It could be just a few individuals, or a few species.

‘We need to keep in mind it’s a wild place out here.’

Another theory why sea otter populations are dwindling is that sharks are attacking female otters, who usually produce eight or more pups in a litter.

Without new generations of otters, the species will continue to struggle.

Mr Tinker said that there is nothing to be done about the supposed shark attacks, calling the trend, calling the shark’s behaviour ‘natural.’

Sea otters are the heaviest members of the weasel family and can weigh anywhere from 35 to 100 pounds.

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Given the disparity in size between otter and shark i should think if the shark is hungry it would eat the otter as you or i would eat a plum. Not much chewing! Otters being Mustelids, they would not be nice to eat, perhaps sharks just mouth them. I would be looking more at the plastic soup these poor creatures increasingly have to live in as the reason for their demise.

Will shark’s fin soup solve the problem?

Why can’t we all get along. Gosh, are those Sea Otters cute. Thankfully, California has decided to bug off them and allow them to exist south of Big Sur, and the Channel Islands. The increase in habitat options can’t hurt but help. Meanwhile, we have a big growing population of sea lions, which should help the Great Whites survive too.

Poor Great Whites get the blame again. It’s nature and why wouldn’t they eat Otters? 200 GWs around Calif. there are only 7-8 GW clusters worldwide, that’s less than 2000 GWs on the planet. I’d feed them Sea Otters every day if it helps them survive!

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