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
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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
California Sea Lions are found off the west coast primarily in the Channel Islands off the California coast. Males can reach up to 850 pounds,
In a documentary film directed by Bill Wisenski, “Threatened: The Controversial Struggle of the Southern Sea Otter,” it reveals some of the reasons why the California sea otter population is declining. In addition, it shows the controversy surrounding the “No Otter Zone”. Furthermore, it ensures why the California sea otter population is important to the marine ecosystem. In the film, sea otter populations are endangered because of the significant impact by some human factors. In the 1700’s and 1800’s, fur traders hunted sea otter population to near extinction. Besides this, threatened events such as shipping and drilling oil across the Pacific and along coastal areas; the California sea otters is vulnerable to oil contamination. As a result,
This creature is known as a harbor seal and was found on October 23rd, 1805 near the Columbia river, 100 miles away from the Pacific Ocean. and found in fresh water. They are also known to be found on the coast of California, they are often found laying on rocks on sandy beaches.
Sea minks are now extinct but were once ranged from Casco Bay, Maine in the south to as far north as New Brunswick, Canada. Their main habitats are coastal regions. Sea minks are usually confused with the American mink, but the sea mink is bigger. Sea minks are on average 914mm but the American mink is 580-700mm, so there is a good difference in size. Also the male sea minks are larger in size compared to the females. Their fur is a reddish dark brown, and it is not known if their fur changes during the summer and winter.
The study conducted by Weisle, Nagaswami, and Peterson is displayed about river otters and how they are different in structure from other marine mammals. River otters must depend on their thick layer of hair for survival. River otters are semi-aquatic mammals, which are considered to have denser fur than any other mammals. It’s thick, sleek coat, which keeps it dry and warm, is made up of two types of hair. The longer outer hairs are water repellent as known as guard hairs, and the other is underhair. The guard hairs could provide some protection for the more delicate underhairs. The three authors of this article, “River otter hair structure facilitates interlocking to impede penetration of water and allow,” addresses a question upon why the
The lecture explained how the population of sea otters declined, due to the environmental pollution. First, the oil rigs along the Alaskan coat serve as an indication to pollution. This directly refutes the reading passage which states that predation was most likely the reason, since the bodies of the dead sea otters didn't wash on the shores.Secondly, the passage mention that the water samples that were extracted from the sea revealed the presence of chemicals. Again, this contradicts with the lecture which claims that the whales which the otters consume were not available anymore. Which had forced the sea otters to change their diet to include small sea animals. Thirdly, the lecture mentions that the decrease in sea otters population was
Southern sea otter lives in kelp forests (a type of seaweed) along the Pacific coast, mainly off the coast of California. The marine mammals consume on average one-fourth of its weight daily including sea urchins, which are vital to support the kelp forests. By the result of sea otters preying on sea urchins, the consumption of kelp by sea urchins are kept at a constant rate allowing the forest to grow and thrive. This is highly important for biodiversity in the sea that is provided by the kelp forest, which is a key component of the three principles of sustainability. There are three ways that human can do to help prevent the premature extinction of southern sea otters. First, ethical issue that consists of the species being seen as vital
They began at the Astoria area then to the Cowlitz River and on to the Bonneville Dam. More recently the Sea Lions have been spotted above the Bonneville Dam and occasionally in the Drano Lake and Mcnary pool.
In this article “saving the sea otters is just part of her normal day at work” by Kitson Jazynka My Opinion was that I think a lot of the sea mammals are dying because the bacteria in the water. First of all,”Otters in Alaska have been dying at a higher than normal rate over the past 10 years.”This quote
Harbor seal Harbor seal is pretty small when compared to other seal species. Harbor seals usually come in dark brown, tan and different shades of grey. They mainly eat fish and shellfish. The harbor seal fits in as a secondary consumer, meaning it is a carnivore and eats primary consumers such as fish.
Sea otters found in Pacific coast: Sea otters allow kelp forests to thrive. Loss of the above mentioned habitat and nutrients provided by kelp leads to great cascade effects on the marine ecosystem. If there is no presence of sea otters then it turns into abundant sea urchins and no kelp forest to feed the marine habitat. Sea otters have been observed to be more important in areas of open coast than protected bays and estuaries. 4.
There are 16 different breeds of otters. Sea otter, Eurasian otter, Lutra, Lontra, oriental small clawed otter, Giant otter, smooth-coated otter, African clawless otter, Northern River otter, Asian small clawed otter, Congo clawless otter, marine otter, neotropical otter, South American otter, spotted-necked otter, and hairy nosed otter. This animal is pretty much always near water, they are usually found near both freshwater and coastal marine, such as, lakes, rivers, inland wetlands, coastal shorelines, marshes, and estuaries. Otters can be found in North America & other places as well. Otters eat fish, crabs, sea urchins, abalones, clams, mussels, and snails. They are preyed on by bobcats, coyotes, mountain lions, wolves, black bears, and
Similarly, sea otters in kelp forests keep sea urchins in check. Kelp roots are merely anchors, and not the vast nutrient gathering networks of land plants. Thus the urchins only need to eat the roots of the kelp, a tiny fraction of the plant's biomass, to remove it from the ecosystem.
The presence or absence of sea otters influences marine ecology at the community-level. Studies have shown that kelp forests enhance the underwater environment, providing a suitable habitat for fishes. The declining kelp beds in California in the mid 1900’s propelled the Kelp Habitat Improvement Project, whereby attempts were made to eliminate sea urchins that are primary predators of kelps. Studies showed that the elimination of sea otters during the 1800s from the Californian waters might be responsible for the dwindling numbers of kelp forests. Further studies have also shown that the population density of sea otters affects seaweed biodiversity as well. In a study conducted in Alaska on three different bays, the Torch Bay, Deer Harbor and the Surge Bay, it was found that the presence of sea otters led to a decrease in the population of sea urchins, which led to an increase in the population of seaweeds. In addition, it was also found that annual kelps predominated the areas where sea otters were present, and perennial kelps predominated in areas that had lesser sea otter populations (qtd. in “Interaction with kelps & sea otters”).
Sea otters, (Enhydra lutris), are considered a keystone species, and for this reason, can be useful indicators of nearshore ecosystem health (Kreuder et al. 2003). With the implementation of the Marine Mammal Protection Act, southern sea otter (Enhydra lutris nereis) populations within their California range rebounded from post fur trade levels of approximately 50-60 in 1938, to more than 3000 today. However, growth rates have been slower than expected for this population (Riedman and Estes 1990). Definitive explanation for this is unclear, but contributing factors may be that sea otters face a range of physiological and environmental challenges to reproduce.