Wednesday, August 28, 2019

Anthropogenic Impact on Mangrove Ecosystems Term Paper

Anthropogenic Impact on Mangrove Ecosystems - Term Paper Example Discussion Mangroves ecosystems are established on the terrestrial marine boundary on sheltered tropical coasts and are vulnerable to both natural and anthropogenic disturbances (Ghosh, 47). Man has lived with the mangroves for a long time and having little contact and exploiting its resources in small scale. However, recent unsustainable use and exploitation of mangrove ecosystems has contributed to extinction and loss of these vital ecosystems. Moreover, direct as well as indirect anthropogenic influences play a major role in determining mangrove composition and extent of coverage globally. Mangroves are salt tolerant tree species and examples include Rhizophora mangle, Avicennia germinans, Laguncularia racemosa, Conocarpus erectus among others (Guo, 401). Mangrove ecosystems form habitant for various biodiversity especially invertebrate fauna such as penaeid shrimps, spiny lobster and over 200 species of fish threatened globally. Human activities cause disturbance of the mangroves . Such activities include: 1 Overexploitation or unsustainable extraction of the mangrove tress and fauna Man continues to harvest mangrove trees for fuel wood, poles, charcoal, and timber for construction purposes. Moreover, mangrove bark is used for commercial production of tannin (Alfaro, 1087). However, small scale and selective extraction of mangrove pose a little challenge on the entire ecosystem, but leads to death of individual trees. Despite being small scale, clear cutting of mangroves contributes to rapid concentration of sulfide in the soil as well as soil acidification. This negatively affects seed regeneration on cleared lands and thus the reason for declining mangrove yields. Man has harvested mangrove fisheries for several years. Some of the fish products extracted include finfish, mangrove oysters, and shellfish. However, extraction of such resources in large numbers for commercial purposes has disrupted mangrove food webs and food chains (Jess et al, 414). Conseque ntly, large-scale extraction of mangrove trees for extraction of wood products or mangrove land reclamation causes a reduction in fish yields since breeding grounds and fish nurseries get destroyed in the extraction process. In addition, man has introduced some species in mangrove ecosystems for instance, the introduction of Tilapia mossambica (Ellison, 219). The introduced species pose stiff competition for available resources in case the species naturalize and lack natural enemies or diseases that check on their population. Moreover, such species may feed on the native species thus leading to displacement and extinction of the endemic species. 2 Pollution of the mangrove ecosystem Human activities near water bodies lead to pollution of the mangrove ecosystem. For instance, oil exploration, drilling, production, transportation through oil pipelines, tanker accidents, as well as international elimination of ship’s ballasts tankers lead to oil pollution of the mangroves. The o il released into the mangrove ecosystem accumulates in the mangrove roots and thus leading to death of several invertebrates, turtles, and fish (Benson & Joseph, 238). The presence of oil in a mangrove ecosystem results in continuous release of toxic hydrocarbon materials into the water system, thus leading to water poisoning. The

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