Projecting the recovery of a long-lived deep-sea octocoral species after the Deepwater Horizon oil spill using structured population models

1. Deep-water coral communities are hotspots of diversity and biomass in the deep sea. Most deep-sea coral species are long-lived and slow-growing, and are thus expected to recover slowly after disturbance. A better understanding of the recovery potential of these organisms is necessary to make appropriate management decisions.
2. We used data from high resolution monitoring of individual coral colonies that were impacted by the Deepwater Horizon oil spill (April 2010) to parameterise and validate an annual, impact-dependent, state-structured matrix model to estimate the time to recovery for each coral colony. We projected the dynamics of three branch states: visibly healthy, unhealthy and hydroid-colonized. Although we implicitly included branch loss in the model, we focused on the short-term return of extant, damaged, branches to a visibly healthy state and did not consider the far longer-term re-growth of lost branches.
3. Our model estimates that, depending on the initial level of...