BRIE'S BRIEF
Sea Otters
Cute, fluffy and a good eater. No, I am not writing about Cody. I am referring to the sea otter! This week Cody, Chase and I will be participating in the sea otter encounter program at the Georgia Aquarium. To help prepare for our visit, I decided to do this week's brief on the sea otter.
THE BASICS
The sea otter is the smallest marine mammal species, but it is the heaviest member of the Mustelidae family. Males weigh between 50 and 100 pounds and are about 4 to 5 feet in length. Females weigh between 30 and 75 pounds and are about 3 1/2 to 4 1/2 feet in length. They rely on thick fur coats to stay warm.
Unlike a lot of marine mammals, they do not have blubber. They are very lean and would be kings at your local gym. But being lean in the wild can be a weakness. With its high metabolic rate, a sea otter must eat 25% to 38% of its own body weight each day to counteract loss of heat due to the cold water it swims in. Any slight injury or mild disease that prevents foraging would be life threatening to a sea otter.
ENVIRONMENTAL IMPACT
Sea otters play an important role in their habitat. They are responsible for maintaining the overall health of their ecosystem. A lot of marine animals depend on kelp forests. Unfortunately, sea urchins eat kelp. They graze down the forests until they are bare. Sea otters, who eat urchins, are critical for controlling the population. The sea otters keep kelp forests healthy, which increases species diversity.
FUR MATTERS
Sea otters have the densest fur of any animal. It is a two-layer system that minimizes heat loss in cold water and allows them to maintain buoyancy. Clean, untangled fur full of air is necessary to survive. If a sea otter is not eating, it is grooming. They will rub their fur to squeeze out water and will blow air in. The air trapped in their fur, in addition to their large lung capacity, creates their buoyancy. As cleanliness is paramount to maintaining their coats, they are flexible enough to groom any part of their bodies.
NATURAL SWIMMERS
From head to toe they are designed to travel through water. Their whiskers are connected to the somatosensory system. This makes them very sensitive and allows for tactile sensing in deep, dark water. Their hind feet are long, broad and flattened, and their tales are short and muscular. They are able to streamline their bodies and use their fully webbed feet and tail together to propel them through the water. As fish are not usually their prey, it is not necessary for them to have the element of speed to survive.
DIET
In the sea otter world, the early otter gets the mollusk. Having two primary feeding sessions in a day, the otters are up before sunrise to find what the ocean has to offer in the way of food. Midday, the otters takes a rest before once again foraging in the afternoon. They finish feeding before the sun sets.
For those otters who did not get enough food during the day, a midnight feast is completely acceptable. Their diet consists mostly of sea urchins, worms and bivalves. Occasionally they will enjoy a little crab or octopus. Their mothers will have dictated how and what they forage for.
FORAGING FOR FOOD
When diving for food, sea otters are very adept at using their front paws to turn over rocks, pick organisms from kelp and dig for clams. They will even catch fish with their front paws instead of using their teeth. That reminds me of the time my human had to catch a chipmunk that Cody brought into the house. Similar to the sea otter, she was adamant about using her hands. I suggested to her several times she try using her teeth.
I think the most amazing thing about sea otters is they use tools. They will pick up a rock from the sea floor and use it to pound open a hard shell or to pry an abalone off a rock. How clever.
FAMILY
Female sea otters are known to be very affectionate to their pups. What better way to enter the world than with love! No wonder they are so playful. The mothers perform all of the tasks of feeding and raising the offspring. The pup mortality rate is high, but experienced mothers do have higher survival rates. Pups without a mother cannot survive on their own in the wild.
TERRITORY
Sea otters stay within two-thirds of a mile of the shore. There are currently large populations along the Russian east coast, Alaska, British Columbia, Washington and California. I could not find information explaining why the Oregon coast is undesirable to the sea otters. Perhaps the sea otter we meet can answer that question.
SURVIVAL
Humans and sea otters have conflicted over fur and food. In the early 18th century, sea otters were hunted by humans for their beautiful thick fur and eaten for food. By the early 20th century, countries were signing treaties to protect the sea otters, which were near extinction.
During my research, I did not find any mention that sea otters ever hunted humans; however, sea otters did have an effect on the shellfish industry. They often competed with humans for the same seafood, and it has been determined the two cannot exist in the same area. The sea otter remains classified as an endangered species.
I found this site where you can see sea otters in the wild. The best time to check it out is in the early morning: https://seaotters.com.
Ciao for now,
Brie
Cody's corner
