16 March 2012 Mangroves are Essential for Adaptation to Climate Change Mangroves have tremendous ecological and social value. The mangrove ecosystem provides income from the collection of mollusks, crustaceans and fish that live there. Mangroves are harvested for fuelwood, charcoal, timber, and wood chips. Ecological services include the role of mangroves as nurseries for economically important fisheries, especially for shrimp. Mangroves also provide habitats for a large number of mollusks, crustaceans, birds, insects, monkeys and reptiles (Wells et al. 2006). Mangrove forests play at least two critical but contrasting roles in mitigating the effects of climate change; one is as a sink for greenhouse gases, especially carbon dioxide, and the other is as a physical buffer of climate change impacts. Mangroves play a major role in moderating the physical challenges of climate change, such as increasing frequency of storms, changing rainfall patterns, rising sealevels and rising sea surface temperatures. Mangrove vegetation can slow down the runoff of floods and invasion of seawater without the need for similar and expensive engineered infrastructure (Bartlett et al. 1993). The area is subject to high tidal variation, monsoon flooding and tropical cyclones, the larger of which tend to damage infrastructure and cause extreme loss of life. Three cyclones (1970, 1974, and 1991) had storm surge heights of at least 8 m. As a consequence, about 500,000 people lost their lives (Islam 2002). Mangroves save lives and property in the coastal area. For example, 10,117 ha of mangrove forest in Chakaria was converted completely into shrimp farms in ten years (1985-1995). In the 1970s this area was covered with mangrove forest and people were protected from storm surge. After conversion to shrimp ponds, the absence of mangrove forests in the area could not adequately buffer storm surge, resulting in deaths following cyclones in 1991 and 1994. Climate change impacts such as floods, cyclonic storms, erosion, and the length or irregularity of the dry season, and thus water supply for relatively quick draining soils will be important factors when considering potential aquaculture development in these areas. Adaptation of aquaculture to climate change in Bangladesh will vary depending on the stakeholders involved, their level of financial capital, location and the type and scale of aquaculture taking place. Appropriate policy making, species diversification, improved culture practices, and mangrove planting should be promoted in the changing environment. Notes 1Institute of Marines Sciences and Fisheries, University of Chittagong, Chittagong-4331, Bangladesh. *E-mail: mrahmanims19@yahoo.com References Ali, A., 1996. Vulnerability of Bangladesh to climate change and sea level rise through tropical cyclones and storm surges. Water, Air and Soil Pollution 94:171-179. Bartlett, K. B. and R. C. Harris. 1993. Review and assessment of methane emission from wetlands. Chemosphere 26: 261-3 20. FAO (Food and Agriculture Organization of the United Nations). 2008. Climate change for fisheries and aquaculture. Technical background document from the expert consultation held on 7 to 9 April 2008, FAO, Rome, Italy. Fleming, C. 2004. Challenges facing the shrimp industry in Bangladesh. American International School, Dhaka, Bangladesh. Islam, M. R. 2002. Vulnerabilities, Opportunities and Emerging Issues as Transpired from Four Regional Workshops. PDOICZM.WP003, Dhaka, Bangladesh. Karmakar, S. and M.L. Shrestha. 2000. Recent climate changes in Bangladesh, SMRC-No.4, SMRC publication, Dhaka, Bangladesh. Sajjaduzzaman, M., N. Muhammed, and M. Koike. 2005. Mangrove plantation destruction in Noakhali coastal forests of Bangladesh: a case study on causes, consequences and model prescription to halt deforestation. International Journal of Agriculture and Biology 7(5):732-734. Salam, M. A., L. G. Ross and M. C. M. Beveridge. 2003. A comparison of development opportunities for crab and shrimp aquaculture in southwestern Bangladesh, using GIS modeling. Aquaculture 220: 447-494. Shahid, M. A., M. A. H. Pramanik, M. A. Jabbar and S. Ali. 1992. Remote sensing application to study the coastal shrimp farming area in Bangladesh. Geocarto International 2: 5-13. Singh, O. P., T. M. A. Khan and M.S. Rahman. 2000. The vulnerability assessment of the SAARC coastal region due to sea level rise: Bangladesh case, SMRC-No.3, SMRC publication, Dhaka, Bangladesh. Syed, M. D. A., Y. A. Hussin and M. Weir. 2001. Detecting fragmented mangroves in the Sundarbans, Bangladesh using optical and radar satellite images. Paper presented at the 22nd Asian Conference on Remote Sensing, Singapore. Venkataratnam, L., S. S. Thammappa, T. R. Sankar and S. Anis. 1997. Mapping and monitoring prawn farming areas through remote sensing techniques. Geocarto International 12: 23-29. Wells, S., C. Ravilous and E. Corcoran. 2006. In the front line: Shoreline protection and other ecosystem stem services from mangroves and coral reefs. United Nations, Environment Programme World Conservation Monitoring Centre, Cambridge, UK. Fig. 5. Perceived importance of various impacts of climate change on aquaculture (n=40 respondents).
RkJQdWJsaXNoZXIy MjExNDY=