Climate Change Vulnerability Assessment and Adaptation Planning ...

5.0 Developing Adaptation Measures5. . .. .. ....5Natural factors promotingaccretion in mangrovesSediment carried to thecoast from streamcatchments and othersources helps buildmangrove soil..Sea level..Accretion.Management actions promotingaccretion in mangrovesRehabilitation ofdegraded mangrovespromotes the growth ofroot mats and sedimentsettling out.Illustration: Jan Tilden.. .. . .. ..... ...Sediment settles from thewater column as mangrovesreduce wave action andtidal velocity. Once sedimenthas settled, these factorsalso help to prevent iteroding away.The expansion of mangroveroot mats is a majorcontributor to accretion.Crabs eat fallen mangroveleaves, pulling theminto their holes. Uneatenleaf matter and crab feceshelp to build up the soil.Healthy mangroves promoteaccretion. Mangroves build up soil,protecting the land from erosionand sea level rise.Healthy sea grasspromotes accretionby damping the energyof waves and tides. Seagrass is also a source oforganic matter that helpsbuild mangrove soil andfeed mangrove wildlife.Healthy coral protectsmangroves and suppliessediment.5Design shore structuresto allow longshoresediment drift, which is animportant source ofsediment for mangrovesin downstream areas.Design dams to allowsediment to pass through.Control boat wakesto reduce erosion.By Jan TildenFigure 66. Actions to enhance accretion in mangroves.100 | Climate Change Vulnerability Assessment and Adaptation Planning for Mangrove Systems