Limits of Resilience: Uncertain Recovery in Mangrove Ecosystems Following Repeated Hurricane Disturbance - NERRS/NSC(NERRS Science Collaborative)

Building on the momentum of an earlier collaborative project, this team and their users reunited to assess how mangrove recovery and resilience is impacted by repeated hurricane disturbance.

The Project
Mangrove ecosystems of the greater Caribbean region face increasingly frequent tropical cyclones. In 2017, mangrove ecosystems at Jobos Bay NERR and Rookery Bay NERR sustained major impacts from Hurricanes Maria and Irma respectively. Just five years later, both reserves were again impacted by tropical cyclones (Hurricanes Fiona and Ian). To evaluate how mangrove recovery and resilience is impacted by repeated disturbances, this project mapped habitat change and assessed hydrological regimes.

This project's approach was adapted from an earlier initiative, the Mangrove Coast Collaborative (MCC). The MCC project had previously shown substantial recovery of the mangrove forest in both reserves after Hurricanes Maria and Irma, but had found persistent areas of minimal regeneration perhaps due to hydrological stress. Drawing on the strong collaborative foundation established by the MCC, this project team was able to mobilize quickly to assess the impacts of Hurricanes Fiona and Ian on ongoing mangrove recovery.

Project users collaborated with the project team via three project advisory committees (PACs) which had previously been established as part of the MCC project. The project advisory committees, two local and one technical, helped guide the project's methods, which included generating habitat and mangrove change maps for each reserve through 2024. Additionally, the team collected data on water depth and porewater salinities in locations of mangrove forest having minimal recovery compared to reference sites to assess the impact of hydrological stress.

Extended mapping of mangrove coverage and hydrology did not reveal additional impacts from Hurricanes Fiona and Ian. Instead, mapping showed an overall trend of increasing mangrove coverage; although locations of low recovery persist in both reserves. Both mapping and hydrologic datasets will serve as useful baselines for continued monitoring. Future research will be able to leverage the infrastructure and data derived from the project, and managers can immediately use the results from the project to influence policy for protection of the mangrove coastline. Finally, both reserves are better situated for future post-disturbance assessment and associated management planning.