Crabs and Costal Erosion

Coastal marshlands protect areas inland from the effects of storms and flooding. They are home to millions of animals and support a huge biodiversity - they are also under threat.

Rising sea levels are making more of the coast wetter for longer, and it is happening faster than the natural growth of the marsh.

This is changing the types of animals that like to live there. For local populations of purple marsh crab (Sesarma reticulatum) - it’s a good thing, as they are thriving in this new environment.

For humans it is less good news. These crabs are gathering in such high numbers that their normal burrowing is becoming a problem for the stability of the marsh. This is especially severe in areas where human overfishing has reduced their natural predators.

The overgrazing of the crabs, combined with rising sea levels is turning marshland into mudflat at an increasing rate. Which poses risks for the human communities that live inland as the natural buffer from storms is being degraded.