Guidelines for a Mangrove Management Plan Cayman Islands, BWI

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Guidelines for a Mangrove Management Plan Cayman
Islands, BWI

• M. L. Anderson

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Mangroves
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.
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Importance of Mangroves

• 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)
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Pollution Mitigation
Importance of Mangroves

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

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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.

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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.

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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.

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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.

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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 subject to drought and wave
  erosion.
• These mangroves will experience increased
  flooding, inundation and salinization.

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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.

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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

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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 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.

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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.

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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.

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Energy Management

• Recommend site-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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The End