This goal aims to assess the amount of protection provided by marine and coastal habitats against flooding and erosion to coastal areas that people value, both inhabited (homes and other structures) and uninhabited (parks, special places, etc.).


Storm protection by coastal habitats saves lives, property and is worth billions of dollars each year. Coral reefs, mangroves, seagrasses, salt marshes, and sea ice act as natural buffers against incoming waves. By protecting against storm damage, flooding, and erosion, these living habitats keep people safe and can help mitigate economic loss of personal and public property, cultural landmarks and natural resources.

This goal assesses the amount of protection provided by marine and coastal habitats by measuring the area they cover now relative to the area they covered in the recent past.The status of each habitat is calculated and their contribution to the total goal score is the average of the habitats weighted by the relative protection they provide.

A score of 100 would indicate that these habitats are all still intact or have been restored to the same condition as in the past. A score of 0 would indicate that these protectie coastal habitats are completely absent, while a low score indicates that these habitats have declined significantly and that more protection and restoration must occur in order for them to store the maximum amount of carbon.

Approximately one-third of the overall area of coastal habitats has been lost in the last 50 years and the remainder is severely threatened. Destruction of these ecosystems means coastal areas are less protected from tidal surges, flooding, and storms. Majour causes of destruction of these systems include draining or clearing for agriculture or aquaculture, coastal pollution, and unsustainable coastal development.


Explore the full description of the data and model used in the Global OHI MODEL. Or, take a look at PRACTICAL GUIDANCE for advice on adapting the goal for future assessments and to learn how previous OHI+ assessments have modified this goal to address differences in data availability or priorities.

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