Otters and Science News: IT'S 2015 SEA OTTER AWARENESS WEEK - Otters are good for the environment. They protect sea kelp forests by eating urchins, which allows a variety of other marine life to thrive

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Pup 696 getting lots of TLC from Monterey Bay Aquarium staffers.

Sea otter mother and pup in the Great Tidepool at Monterey Bay Aquarium

Otters are excellent mothers to their adorable pups

Continue reading and see more images of these wonderful creatures

Sea otters can be fairly ingenious, doing things like using rocks to hammer away at shellfish. In fact, the animals will use just about any hard surface to break open dinner, including boat hulls and aquarium glass.

The northern sea otter, such as these ones in Kodiak Island in Alaska, is doing better than its southern cousins because they have more room to expand their populations.

Otters wrap themselves in kelp fronds to keep from floating away while they nap.

Picture of sea otters

Otters are good for the environment. By preying on species such as urchins - who eat kelp - they protect the kelp forest where many other species can thrive.

Picture of sea otter

Otters are extremely devoted mothers. They need to forage for up to 14 hours a day to be able to nurse the growing pup.

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From the Defenders of Wildlife website:

BASIC FACTS ABOUT SEA OTTERS

The heaviest members of the weasel family, sea otters are also the second smallest marine mammals. Unlike other marine mammals, they do not have a layer of blubber to help them keep warm. Instead, sea otters have the densest fur in the animal kingdom, ranging from 250,000 to a million hairs per square inch, which insulates them.

Sea otters are good for the environment

Sea otters are a keystone species, meaning their role in their environment has a greater effect than other species. As predators, sea otters are critical to maintaining the balance of the near-shore kelp ecosystems.

Without sea otters, the undersea animals they prey on would devour the kelp forests off the coast that provide cover and food for many other marine animals.

Additionally, sea otters indirectly help to reduce levels of atmospheric carbon dioxide, a prevalent greenhouse gas, as kelp forests play an important role in capturing carbon in coastal ecosystems

Diet

Sea otters eat urchins, abalone, mussels, clams, crabs, snails and about 40 other marine species. Sea otters eat approximately 25% of their weight in food each day to support their high metabolism.

Population

Historically, sea otters numbered between several hundred thousand to more than a million.

But due to the fur trade, worldwide numbers plummeted down to a total of 1,000-2,000 in the early 1900s. Today, there are estimated to be just over 106,000 worldwide, with just under 3,000 in California.

Habitat & Range

Sea otters live in shallow coastal waters off the northern Pacific. Their historic range stretched from Japan, along the coast of Siberia and the Aleutian Chain and down the Alaska, British Columbia, Washington, Oregon and California coast to Baja California.

Currently sea otters can be found in Canada, Russia, Japan, California and Washington, but the majority of all wild sea otters are found in Alaskan waters. Recent reports of sea otter sightings have also occurred in Mexico.

In the U.S., there are two distinct sea otter subspecies, the Northern sea otter (Enhydra lutris kenyoni) and the Southern sea otter (Enhydra lutris nereis). Northern sea otters are found in the Aleutian Islands, Southern Alaska, British Columbia, and Washington.

Southern sea otters, also known as California sea otters, live in the waters along the California coastline and range from San Mateo County in the north to Santa Barbara County in the south.

Behavior

Sea otters spend much of their lives in the water and can dive up to 330 feet when foraging for food. They sometimes rest in coastal kelp forests, often draping the kelp over their bodies to keep from drifting away.

Sea otters are also one of the few mammals other than primates known to use tools. They use small rocks or other objects to pry shellfish from rocks and to hammer them open.

Reproduction

Mating Season: Throughout the year
Gestation: 6-8 months
Litter Size: Generally one pup, but sea otters can give birth to twins

Read more - http://www.defenders.org/sea-otter/basic-facts

Threats to Sea Otters

It is estimated that the worldwide population of sea otters once numbered between several hundred thousand to over one million before being nearly hunted to extinction by fur traders in the 1700s and 1800s.

Sea otters finally gained protections with the signing of the International Fur Seal Treaty of 1911, and became listed under the Marine Mammal Protection and Endangered Species Acts in the 1970s.

Worldwide, numbers have slowly recovered but still stand far below original population numbers. While sea otters are vulnerable to natural predators, their populations are significantly impacted by several human factors as well.

Conflict with Humans

Direct conflict with humans, such as shootings and entrapment in fishing traps and nets pose a major threat to sea otter populations.

Since sea otters eat many of the same shellfish humans like to eat, such as sea urchins, lobster and crab, they often find themselves in the same areas fishermen like to harvest.

Some shell fishers view sea otters as competition and a threat to their economic gain. Many fishermen use fishing gear that can entangle sea otters and cause them to drown.

Whether intentionally or unintentionally, sea otters who find themselves too close to a fisherman’s harvest are often harmed or killed.

Fortunately, the number of sea otters deaths from human conflict is slowly decreasing as a result of their protection under the Endangered Species Act and increased regulation of fishing nets.

Oil Spills

Oil spills from offshore drilling or shipping are an immense threat to sea otter populations.

When sea otters come into contact with oil, it causes their fur to mat, which prevents it from insulating their bodies.

Without this natural protection from the frigid water, sea otters can quickly die from hypothermia.

The toxicity of oil can also be harmful to sea otters, causing liver and kidney failure as well as severe damage to their lungs and eyes.

A historic example of the impacts oil spills have on sea otters is the 1989 Exxon Valdez oil spill in Alaska’s Prince William Sound, which killed several thousand sea otters.

Sea otters are still threatened by events like this because countries around the northern hemisphere continue to ship and drill for oil throughout the Pacific and along coastal areas that sea otters call home.

Because their numbers are low and they are located in a rather small geographic area compared to other sea otter populations, the California sea otter is especially vulnerable, and could be devastated by oil contamination.

Habitat Degradation

Pollution on land runs off into the ocean, contaminating the sea otters’ habitat. This can jeopardize their food sources, as well as harm them directly.

Sea otters are often contaminated with toxic pollutants and disease-causing parasites as a result of runoff in coastal waters.

In California, parasites and infectious disease cause more than 40% of sea otter deaths. Hundreds of sea otters have succumbed to the parasites Toxoplasma gondii and Sacrocystis neurona, which are typically bred in cats and opossums.

Scientists have also reported the accumulation of man-made chemicals, such as PCBs and PBDEs, at some of the highest levels ever seen in marine mammals.

Defenders of Wildlife works tirelessly to protect sea otters and the marine habitats they rely on for survival. From eliminating a “no otter zone” created by the U.S. Fish and Wildlife Service, to helping establish sea otter conservation projects, we continue to fight for these animals that play such an important role in marine ecosystems.
Read more >>

Photo Emmanuel Keller

From SeaOtters.com:

Reproduction

Sea otters are polygynous, meaning that males have multiple female partners. Males are usually territorial, typically mating with several females in an area that they defend.

Males and females form breeding pairs for several days, after which time the male moves on to look for other receptive females and the female is left to ultimately raise the pup on her own. Females often sport bloody noses during the breeding season, as males will bite them during mating.

Female otters can give birth at any time of the year. Gestation lasts approximately 6 months.

It takes 4 months for the fetus to fully develop but delayed implantation (of approximately 2 months) almost always occurs. Scientists suggest that this adaptation may help mothers give birth at the most opportune time of year—when food is most abundant, for example.

At birth, pups are approximately 2 feet (.6 m) in length and weigh 4-5 lbs (2-2.3 kg). Pups are born with a thick coat of baby fur and are so buoyant they cannot immediately dive for food.

The mother carries the pup on its chest for the first two months, where it is constantly groomed and protected from the cold water.

When diving for food, the female leaves her pup floating in the water, often times wrapping kelp fronds around the pup to keep it from floating away.

The mother-pup bond is strong. Mothers have have been known to carry their pup for several days after the pup’s death.

Pups begin to dive and forage at about 2 months, although nursing continues until weaning.

They have high-pitched calls, which they use to communicate with their mothers.

Females typically nurse their pups for 6 to 12 months, before abruptly weaning and abandoning them.

Within a few days of weaning her pup, a female will come into estrous and mate again.

Pup mortality is high – only 25% of pups survive their first year. Females mature at age 3 and males at age 5. Wild otters typically have a lifespan between 15 and 20 years.

Read more about otters here:
http://seaotters.com/sea-otters/

Photo Marac Andrew Kolodzinski

The Monterey Bay Aquarium's goal is always to return sea otter pups to the ocean once they’re ready to survive in the wild

Read the story of pup 696's rescue by Monterey Bay Aquarium staff: http://montereybayaquarium.tumblr.com/post/112617067463/otter-twins-this-guest-blog-was-written-by

For more information about the Monterey Bay Aquarium's animals and exhibits, and to view their live web cams, please visit http://www.montereybayaquarium.org/