River Otters Research Paper

The area of research that I have selected is the effects of overfishing in the Sea Otter ecosystem off the coast of California. The effects caused by the fishing pressure on the ecosystem will have different outcomes, depending on the strength and the types of relationships of the organisms present. (4) Red Abalone populations have declined drastically, to the point of the abalone fishery collapse. Several factors have led up to the collapse including Withering Syndrome, where the organism loses the ability to attach itself to rocks, making it more susceptible to predation, or the organism can eventually wither and starve to death. Sea Urchins and Red Abalone are a part of the same ecosystem, and are competitors of each other.(5) Both organisms graze on macroalgae and are a primary food source for Sea Otters. Sea Otters occurred from the North Pacific Rim down to Baja California, Mexico, but now only occur in small isolated patches (9) It is understood that Sea Otter presence can characterize community structure, where they can control and determine the size of Sea Urchin and Red Abalone populations. In the absence of Sea Otters, “Urchin Barrens” are created from the overgrazing of macroalgae by Sea Urchin. In these areas the ecosystem have changed dramatically, due to the overfishing, or in this case the over hunting, of Sea Otters causing a trophic cascade.(7)In some areas, Sea Otters have been reintroduced, in other areas they were never removed, and in others they

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.

Firstly, the author states that pollution sources such as oil rigs near Alaskan beaches is killing the sea otters. Also, a research held on water samples in the area showed that it contains high levels of chemicals that may indirectly kill the otters. This view is objected by the lecturer. He proposes that Orcas use the animals as source of food, that is why there are no signs of dead otters on shores of Alaska, which would however be

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

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

The Brown-throated Three-toed Sloth is approximately the size of a house cat, ranging from 45-60cm. Like all sloths it has long limbs and a small head for the size of its body. Sloths’ fur hangs ‘backwards’ compared to other mammals, lying from the stomach to their back. This enables the water to run off while it is in a tree. Sloths do not have visible toes but instead have long claws. In this species they have three claws on each foot, which enable them to hang from the branches of trees (2). The brown-throated Tree-toed Sloth can also be distinguished from other species by its brown fur and upturned mouth, giving the sloth a constant ‘smile’.

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

levels of chemicals which might have caused the decline of sea Otters. However, the lecture argues that Predation theory is

The sea animal I chose was a southern sea otter. Sea otters inhabited the North Pacific Rim of the Pacific Ocean, from Hokkaido, Japan, through the Kuril Islands, Kamchatka Peninsula, Commander and Aleutian Islands, Alaska, and south along the west coast of North America down to Baja California, Mexico. Scientist have evidence found in fossil records, that sea otters and their relatives have been a major part of the California’s ecosystem for the past five million years but by 1830 sea otters became very rare in California. Scientific evidence to suggest Otters have been on Earth for the past 23 million years. It is speculated that the Otter as it is today could have evolved monumentally about 7 million years ago.

“Atmospheric carbon dioxide (CO₂) concentrations have increased by approximately 40% since the start of the Industrial Revolution” (Wilmers et al. 2012). This increase in atmospheric CO₂ is a leading cause and contributor to Earth’s climate change with effects such as: “measurable global heat retention and elevated atmospheric temperatures, partial melting of the polar ice caps, ocean acidification, and a host of other impacts on Earth’s environments” (Wilmers et al. 2012). Earth’s ecosystems are combating this climate change by helping reduce the concentration of CO₂ and “sequestering C” (Carbon) in the atmosphere through “photosynthesis” (Wilmers et al. 2012). “Kelp forests are among

A chestnut colored, furry blur races past you as you are paddling your boat in a North American lake. You wonder what it could be! It is a river otter. In this essay, I will be telling you about this interesting member of the weasel family.

One such example is their excellence in swimming. Researchers who observe sea otters in the wild found them swimming at speeds of up to nine miles per hour. Furthermore, sea otters can float and swim on their backs on the surface of the water and remain underwater for six to eight minutes. They can dive to depths of over one-hundred thirty feet on average.

The article claims that the population of the sea otter has declined because of pollution, pradators and, uneven pattern of ocean currents. On the other hand, the professor does not believe factors of why otters dissappered and opposes each reason.

Finally, the unpatterned of sea otter decline is attriputed to Orca hunting area accessibility not due to water pollution as the reading indicated. The professor mentions that, due to it large body size, Orca can not access shellow water or rocky area. However, they hunts perfectely in a deep water. Therefore, sea otters number increase in shellow water and rocky areas and decline at deep water. Thus, this explain the unpatterned of sea otter decline.

Sea otters (Enhydra lutris) are marine mammals capable of spending their entire lives in water. Being carnivorous in nature, they feed on sea urchins, crabs, fishes, mussels and clams. They are referred to as keystone species due to their profound impact on marine ecology. The interaction between sea otters, sea urchins and kelp forests has been studied as a model of the impact of predator-prey interaction on community ecology. Sea otters are keystone predators, whose presence has a far-reaching influence on the marine food web by affecting the population of sea urchins in particular, and kelp forests & other marine organisms in general. There has been a steep decline in sea otter populations due to water pollution and exploitation for