Sea Otters Summary

The conditions that the captured killer whales are forced to live in are not acceptable replacements for the wildlife habitats that they have been ripped from. All the enclosures that the orcas are kept in do not provide an adequate amount of space that the animal requires. The size of an orca in relation to the size of the tanks they are forced to live in is comparable to 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

I believe that underwater noise has an effect on marine animals such as whales. Using information from the passages I will prove my point. Their numbers are declining rapidly and I believe that underwater noise has some involvement in the rapid decrease in their population numbers. The information given within the two passages will help prove my point.

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

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,

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 reading passage tries to give some reasons to show that the number of sea otters, a small mammal living along the western coast of North America, has significantly declined because of the environmental pollution. On the other hand, the professor on the lecture looks at this concept through a different lens and believes that attacking by the predators like orca are possible for this problem.

The lecture and the reading both discuss the decline of Sea Otters. While the reading states that the pollution is the

The effect of the new wolf population was a miracle beyond hope, the ecosystem began to recover and diversify greatly. When the wolves were introduced it was found that they killed elk and restored their numbers to something the ecosystem could carry in conjunction with other species who feed on similar resources. In this way a surge of beaver population can be noted, as a result of beaver population increase the rivers became more stable and lodging was created for a half dozen species. It was also found that with the hunting of elk wolves left behind food for other animals whose populations also greatly benefited from this new predator. With the reintroduction of this alpha predator, the ecosystem made great strides toward recovering and diversifying, stream traveled slowly, meandered less and forest began to grow anew. Despite some arguments that Grey Wolves are a menace to the area or sensationalist report trying to discredit the wolf the results are clear. While man was responsible for the over hunting of the Grey Wolf in the 20th century, at its end the mistakes were rectified and the ecosystem shifted back into

In the lecture is suggesting that the desapear of whales, the main hunting Orcas, by human hunters is the real cause of the decline of sea otters and other species maintionated in the reading passage, because of that the Orcas need to adapt their diet.

The speaker cast doubts on the idea that pollution is the my cause for otter popullation decline. According to the Speaker, instead of pollutions but over hunting of whales could be the main cause for the otters incidence decline would predatation. Therefore the speaker asserts that decrease in the otter population could be linked to new a new predator in its habitat: orcas in search for new preys to replace the shrinking population of their natural preys, the whales.

One hypothesis proposes that the reason Steller sea lions have been declining is because of low prey abundance. Animals should use their energy efficiently when they forage to maximize the net amount of energy gained in relation to the amount time and energy that is spent, but it is believed that the reason Steller sea lions are disappearing in such big numbers is because when prey abundance is lower, that Stellar sea lions are less efficient predators (Charnov, 1976). In a recent study conducted on the effect of prey abundance on foraging efficiency, it was found that the less prey that Stellar sea lions had available, the less efficient they were in foraging (Goundie et al., 2015). In the experiment, the researchers took 4 adult Stellar sea lions and had them dive up and down a tube while recording their oxygen consumption, and dive duration. The sea lions dove between the surface of the water and depths of 10 m, and 40 m, and the reason for this was to simulate diving depths of Steller sea lions in the wild (Merrick and Loughlin, 1997). While the sea lions were diving, researchers fed them pieces of fish through two different tubes that were placed away from each other in order to simulate real foraging movements and prey densities. The researchers fed the seals 12 pieces of fish in the

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”).