Salt marsh die-off and recovery reveal disparity between the recovery of ecosystem structure and service provision

Coastal ecosystems, such as sand dunes, salt marshes, and mangroves, stabilize shorelines and protect coastal populations. In New England, salt marshes have experienced widespread cordgrass (Spartina alterniflora) die-off and habitat loss, and it is unknown how this has affected their ability to provide coastal protection. We quantified wave attenuation and shoreline stability on healthy, die-off and recovered marsh creek banks. We found that coastal protection has been severely compromised by salt marsh die-off, and that to date, S. alterniflora recovery, while superficially impressive, has not returned this ecosystem service to the levels of intact marshes. Climate driven sea-level rise and predicted increases in the frequency and severity of storms over the next century will likely further increase the vulnerability of coastal populations. Therefore, recovery of coastal protection is essential for maintaining the ecological and economic wellbeing of coastal communities. Our results suggest that quantification of the recovery of ecosystem services should be employed in order to successfully measure recovery in degraded ecosystems.