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
The Title of this essay is called “What is the Major Problems with Pollutants on the Great Lakes”. The essay explains that there is a problem going on in the Great Lakes with people who live around the Great Lakes area in that what they are throwing into the lakes; whether it would be from trash or fecal matter it is all causing major effects on the ecosystem on the Great Lakes, in turn effecting the fish and water we consume. This is not only a major problem for the lakes but also the humans that depend on those lakes.
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
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
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 author uses cause and effect to show the population of our fish decrease its numbers.
"Polar Bears, Ringed Seals, and the Complex Consequences of Climate Change" is an article written by Mary Bates who earned her PhD studying Bat echolocation. She works for an American Association for the Advancement of Science. In this article Mary talks about how Climate change is impacting different species at different rates. Here, she focuses on sea-ice dependent animals such as Polar Bears and Ringed Seals at Arctic. She explains on how these animals are dependent upon the sea-ice for living. The Arctic is warming at a rate three times greater than the global average, and that the sea ice coverage is declining rapidly. She also talks about Hamilton's study on sea-ice dependent animals. Before the melting of sea ice the Polar bears used
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 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.
First, the article states that pollution of ocean by industrial chemicals, oil rings caused to decrease otters' population. Otters cannot survive polluted ocean since their resistance ability cannot afford it. So, they died because of pollution. In contrast, the professor believes that pollution should kill other spicies in the ocean. However, population of other spicies is stable. Furthermore, there is no evidence that ocean is polluted. If ocean had been polluted, there would be huge effect on
The lecture indicated that the rapid decline in sea ottor number is contriputed to predators like Orca. The professor mentions that Orca hunt and eat sea otters. Therefore, no sea otters bodies are washed out in large number. If there is water pollution, sea otters bodies should be wahed out along the coast line in larg number. Thus, this why the professor refute the water pollution hyposize.
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”).