Guidelines for a Mangrove Management Plan Cayman Islands, BWI. M. L. Anderson

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1 Guidelines for a Mangrove Management Plan Cayman Islands, BWI M. L. Anderson

2 Knowledge of mangrove ecosystems: and how they react to external influences such as changes in the water table, changes in salinities and the impact of storms is important in determining the reaction of mangroves to climatic changes and how climate change will affect the mangrove protected coastlines of tropical lowlands.

3 Coastline Protection Mangroves protect the coastline by acting as wave breaks. Mangroves were proven as protective barriers for many settlements located behind them during the Dec. 26, 2004 Sumatran Tsunami event. The physical stability of mangroves helps to prevent shoreline erosion, shielding inland areas from severe damage during hurricanes and tidal waves. Mangroves can be damaged by storms or freezes but usually recover. Coastal Red Mangrove thrive at South Hole Sound (MA 2002)

4 Pollution Mitigation Mangroves contribute to improved water quality by filtering and assimilating pollutants, stabilizing bottom sediments, and protecting shorelines from erosion.

5 Mangrove Services Millions of people benefit from the services provided by mangroves such as: (1) providing habitats for mollusks, crustaceans, birds, insects, monkeys and reptiles; (2) serving as nurseries for economically important fisheries and shrimp; (3) filtering pollutants; (4) stabilize coastal lands by trapping sediments, (5) binding pollutants (6) provide fuel-wood, timber and charcoal (7) act as bio-shields, mitigating the effects of storm surges and tsunamis.

6 Mangrove Management Strategies If mangroves are to survive the effects of climate change and continue to provide services, we need to be proactive in developing climate change-oriented mangrove management programs.

7 Mangrove Management Strategies As the threat of global warming and sea-level rise looms over us, one of the most at-risk ecosystems are mangroves, especially those that reside on and around low-relief islands and those deprived of sediment, are particularly vulnerable to sea-level rise. By understanding the resilience of specific mangroves to undergo and respond to climate change and disturbance, while maintaining their functions, natural resource managers can identify and protect refuges that stand the best chance for survival.

8 Mangrove Management Strategies Mangroves provide income from the collection of mollusks, crustaceans and fish, and they provide habitats for an even larger number biota. They serve as nurseries for economically important fisheries and shrimp and filter pollutants, and stabilize coastal lands by trapping sediments, binding pollutants and serve as protection from storms. They are also harvested for timber, charcoal, wood chips and fuelwood. The annual economic value of mangroves, based on the services that they provide is between $200,000 to 900,000 per hectare.

9 Assessing Mangrove Vulnerability to Sea Level Rise In planning for sea-level rise, managers need to identify and protect mangroves that are more likely to survive these changing conditions. The most vulnerable mangroves are those that: 1. Grow on low relief islands with low rates of sediment and peat accumulation. The are particularly vulnerable to sea level rise because they are a subject to drought and wave erosion. These mangroves will experience increased flooding, inundation and a salinization.

10 Assessing Mangrove Vulnerability 2. Have a lack of rivers which provide a source of sediments and freshwater. 3. Are within carbonate settings, such as coral atolls and small islands where landward migration to escape transgressions may not be possible, and the sediments are limited as they are locally derived. 4. Are blocked by human infrastructure or topography that will prevent the mangroves from moving inland as the sea-level rises.

11 Assessing Mangrove Vulnerability 5. Are in micro-tidal, sediment starved environments, such as small Caribbean islands, which lack the amount of sediment supply needed to withstand inundation. This will lead to decreased geographic distribution and reduced species diversity in those regions

12 Strategies that Promote Resilience Although sea-level rise cannot be prevented, there are steps that managers can take to mitigate the threats and increase the viability of the mangroves by enhancing their resilience. 1. Apply risk-spreading spreading strategies to address the uncertainties of climate change. Managers should identify and protect representative species, habitats and sources of seeds to ensure replenishment following disasters. A range of mangrove habitats should be protected. 2. Identify and protect the mangroves that are the most naturally positioned to survive climate change.

13 Strategies that Promote Resilience 3. Manage anthropogenic stressed on mangroves. Healthy mangroves need to be protected from human threats which will make them more resilient to climate change. 4. Establish greenbelts and buffer zones to accomodate future mangrove migration and to reduce the impacts from adjacent land-use practices. Greenbelts will mitigate damage from typhoons, tsunamis, tidal surges, cyclones and geomorphic erosion 5. Restore degraded areas that have the necessary components for resistance to climate change. 6. Preserve the connections between mangroves and their sources of freshwater and sediments and between mangroves and associated habitats such as sea grasses and coral reefs.

14 Strategies that Promote Resilience 7. Establish base-line data and monitor the response of mangroves to climate change. As there are only a limited number of pristine mangroves in existence, it is important to establish base-line data which includes tree stand structure, tree abundance, species richness, species diversity, quantity and diversity of invertebrate populations, primary production of bio-mass, nutrient export, hydrologic patterns and sedimentation rates. 8. Create alternative livelihoods for mangrove- dependent communities as a means to reduce mangrove destruction and foster sustainable practices. 9. Identify the stakeholders and generate the funds and support needed to respond to the impacts of climate change.

15 Energy Management Recommend site-specific specific renewable energy alternatives to reduce the dependence on foreign oil and lower greenhouse gas emissions, reduce energy- based pollutants in the local ecosystems. A combination of solar, wind, wave, current and OTEC resources will be recommended.

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