The community ecology of the organism - Research Paper Example

? 29 May Focuses on the Community Ecology of Sea Otters and the Implementation and Effects ofthem being put on the Wildlife Management Endangered Species List Introduction 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 for the impact of predator-prey interactions on community ecology. Sea otters are keystone predators, whose presence has a far-reaching influence on the marine food web by affecting the populations of sea urchins, which indirectly affects the populations of kelp forests & other marine organisms. There has been a steep decline in sea otter populations due to water pollution and exploitation for furs. This has affected marine ecology adversely. It is therefore suggested that sea otters should be included in the endangered species list to protect them from further exploitation. This study focuses on the community ecology of sea otters and their impact on marine ecology. The need for their inclusion in the Endangered Species list and implications of such an intervention are also evaluated. Community ecology Sea otters predate on many herbivorous invertebrates, including sea urchins. Sea urchins feed on kelps, which are an important habitat for fishes and other marine organisms. A high population of sea urchins has an adverse effect on kelp forests. Since sea otters predate upon sea urchins, their populations are kept in check. “This reduces the grazing pressure on kelp, facilitating macroalgal growth” (Laidre). Therefore, sea otters play an indirect, yet vital role in the preservation of kelp forests. This in turn protects kelp forests and other macroalgae, which would have otherwise been depleted due to grazing by sea urchins. “Where sea otters abound so do lush kelp forests, and where sea otters are absent the habitat is typically deforested by hyperabundant sea urchins” (Soule et al 1240). The significance of this interaction can be wholly surmised only when the importance of kelp forests is understood. “Kelp forests are a source of food and habitat for dozens of other coastal species” (Soule et al 1240). Innumerable coastal marine organisms thrive on kelp forests, enhancing biodiversity of the region. Therefore, to maintain the diversity and richness of coastal marine ecology, sea otters should be preserved, who indirectly lead to the preservation of kelps. Impact of sea otters on community ecology 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 too. 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” (“Interaction with kelps & sea otters”). 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”). As is evident, sea otters are vital for maintenance of kelp communities that are primary habitats of other coastal marine organisms, including fishes. Their absence would lead to a significant reduction in marine biodiversity. Inclusion of sea otters in the Endangered List In view of the influence of sea otters on coastal marine ecology and underwater communities, their value in maintenance of coastal biodiversity cannot be undermined. Unfortunately, their populations have shown a steep decline over the years. The sea otter was widespread throughout Western Europe, but its numbers declined dramatically during the 20th century (Chanin 6). The sea otters completely disappeared or were reduced to a rare minority in most parts of the world. They are now an endangered species owing to widespread diseases, pollution of water through sewage and chemical contamination, oil spills and pesticides, apart from being shot by hunters for their soft, thick and waterproof fur. Mortality from natural predators is another cause of concern (“Impacts of Biodiversity”). The continuing decline in sea otter populations have therefore led to population explosion of sea urchins, which are its primary prey. The overpopulation of sea urchins is, in turn, affecting the kelp communities on which they feed voraciously. Overpopulation of any one organism in the community affects the population of its prey, resulting in habitat degradation, imbalance of ecosystem and biodiversity (“Community Ecology”). Therefore, protection of sea otters is an international concern. Sea otters are a keystone species and protecting them indirectly leads to preservation of the biodiversity of an entire or at least a part of an ecological community. In regions of barren marine ecosystems, the introduction of sea otters leads to a substantial and rapid increase in kelp populations, which in turn harbor other marine organisms. For instance: Prior to 1963, southern Monterey Bay had dense populations of sea urchins, but little kelp. Within a year of incursion of sea otters, the area became mostly free of sea urchins and beds of giant kelp Macrocystis and other seaweeds were abundant (“Interaction with kelps and sea otters”). Sea otters must be included in the Wildlife Management Endangered Species list to protect them from further deterioration. It is only through widespread conservative measures that sea otters can be saved and their optimal populations restored. This would in turn lead to the preservation of coastal marine ecology and biodiversity through the preservation of kelp communities. Implications of including sea otters in the endangered list Considering the impact of sea otters on marine ecology, their conservation under the wildlife endangered species act is an extremely worthwhile affair. It will not only preserve sea otters but also many other species whose primary habitats are the kelp forests. Therefore, allocating resources to the preservation of this one keystone species will ensure the preservation of many others. Mobilizing funds by national and international governments for the preservation of their habitat and prevention of hunting is thus warranted. However, it must be ensured that the sea otter conservation methods lead to the achievement of ecologically effective population densities or else, the entire exercise will be futile. This is because mere restoration of their population will not restore marine ecology and kelp forests, unless an optimum population density is achieved (Soule et al). Conclusion In conclusion, it can be stated that sea otters form an important part of the marine ecology, and conserving them leads to the preservation of an entire coastal marine biodiversity. Including them in the wildlife management endangered species list is therefore suggested to prevent their deterioration from pollution and human exploitation. Allocation of funds and resources towards their conservation is recommended to ensure a vibrant marine community that comes under the purview of kelp forests. Works Cited Chanin, P. Ecology of the European Otter. Peterborough: English Nature, 2003. Web. 28 July 2011. http://ec.europa.eu/environment/life/project/Projects/index.cfm?fuseaction=home.showFile&rep=file&fil=SMURF_otter.pdf Community Ecology. eaglenet.lambuth.edu. Web. 28 July 2011. http://eaglenet.lambuth.edu/facultyweb/science/biology/RCook/community%20ecologyS10.pdf Impacts on Biodiversity. Quebec Biodiversity Website. Web. 28 July 2011. < http://redpath-museum.mcgill.ca/Qbp/3.Conservation/impacts.htm> Interaction with kelps & sea otters. asnailsodyssey.com. Web. 28 July 2011. http://www.asnailsodyssey.com/LEARNABOUT/URCHIN/urchPopu.php Laidre, Kristin L. “Sea otter (Enhydra lutris) community ecology”. staff.washington.edu. Web. 28 July 2011. < http://staff.washington.edu/klaidre/otter.html> Soule, Michael E et al. “Ecological Effectiveness: Conservation Goals for Interactive Species.” Conservation Biology 17.5 (2003) : 1238-1250. Read More