Causes Of The Decline Of Sea Otters

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

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

Sea Otters as well as many other species are in danger because of Climate Change.The sudden change in climate has disturbed the ocean’s temperature which causes an insufficient amount of food for sea otters which causes the otters to be malnourished and starved. Because of the change in climate there has been a decrease in the amount of harp seals (Foley, 2013) which happens to be the killer whales main prey, because of this the killer whales have now turned to sea otters. Other likely threats to sea otters because of climate change are ocean acidification in the north Pacific, pathogen transport, marine invasive species, biotoxins withdrawn in bivalve prey, and the recurrence and intensity of storm events (Doroff and Burdin, 2015) . Sea otters have a noticeably solid influence on the wealth of kelp through the impact they have on sea urchins, said James A. Estes, a professor of ecology and evolutionary biology at the University of California, Santa Cruz who was a co-author on Schmitz 's 2014 review and on the original sea otter study. Otters eat urchins. Urchins eat kelp. So in ocean patches where otters are bountiful, urchin populations collapse and kelp tends to thrive (Estes,Cruz and Schmitz,2014). The study, led by Wilmers and published in 2012, found that across the otter 's range the animal could be indirectly at fault for getting rid of as much as 8.7 million tons of carbon dioxide, more than twice what an average

The lecture and the article cover the decline in sea otters population in the recent few years. Two main theories arised to explain that rapid decline. Pollution is suggested as the main reason behind this decline by the author. However, the lecturer opposes that. He believes that Predation is the main cause.

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

In the article, the author states, “The fastest decline among the animal populations were found in freshwater ecosystems, where numbers have plummeted by 75% since 1970” (Damian Carrington). The evidence suggests that the freshwater ecosystems have endured the most pollution compared to any other ecosystem. In other words, aquatic animals are the fastest dying group of animals, which shows how we are affecting the environment by our actions. The author also states, “Otters were near extinct in England, but thanks to conservation efforts, now live in every country” (Damian Carrington). This example suggests that a whole species had almost been killed off because of the pollution in freshwater ecosystems.

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

Both the passage and the lecture discuss the decline of some sea otters’ population in Alaska coast. On the one hand, the passage argues that this decline is due to environmental pollution. On the other hand, the lecture opposes by stating that predation is most likely the reason for the phenomena.

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.

Both the reading and lecture talk about the extinction of sea cows. The reading claims that there are three reasons about the extinction of sea cows. Howevere the lecture argues that no evidence proves those reasons that are correct. Thus, the lecture holds an opposite view of the reading.

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.

Based on this study, researchers can know what is the rate of fertilization and where mortality rate is greatest, also they can use this population to create a model population to see what is the cause and how they can prevent this. These results are important because it showed the evolution of the population and it helped to see if minimizing the threats is an effective solution and how these threats are affecting the right whales. Also, it can help assess the recovery of depleted populations, evaluate conservation threats and also to use whales as indicators of the health of local ecosystems (Fretwell 2014). Doing this study was complicated because the old population was not clear, and assumptions had to be made, such as the population size at each class. Therefore, the sample size can affect the end result. Also, assumptions had be made in the future population in regards of the population in each age class, but it was based from a journal.

Sea otters are a very important species, they effect a lot of animals, and even humans! First the author wrote, the reserch follows ona disturbing trend: Northern sea otters in alaska have been dieing… scientists say bacteria is to blame. The bacteria that is killing sea otters is in the water, which means it can affect our

-For the past 200 years, habitat loss and pesticide intake have been the main factors associated with declines in Bald Eagle populations. People are attracted to water which are the main nesting areas for Bald Eagles, reducing their habitat. Another factor that has affected the Bald Eagle is water loss. People have consumed so much fresh water that it has affected Bald Eagle habitat. A huge problem with Bald Eagles have been poaching. Bald Eagles were once seen as a threat to chickens, livestock, and game so they were often shot by ranchers, farmers and