Disturbance in Mesophotic Coral Ecosystems and Linkages to Conservation and Management

Disturbances are a natural part of the ecology of reef ecosystems including mesophotic coral ecosystems (MCEs). Storms, thermal stress, and volcanism are all documented as direct or indirect impacts on MCEs and have been shaping these systems for millennia. In general, anthropogenic disturbances are increasingly challenging community resistance and resilience and, in some cases, altering community composition. Potential anthropogenic disturbances to MCEs include the effects of climate change (warming waters, extreme temperature fluctuations, sea level rise, and increased intensity and frequency of storms), ocean acidification, physical impacts (marine debris, anchoring, benthic infrastructure, and other mechanical disturbances), harvesting for fisheries and the aquarium trade, impacts from coastal development (turbidity and sedimentation), pollution, invasive species introduction, and increases in disease outbreaks. Many of these disturbances are shown to impact MCEs, with subsequent degradation occurring just as these systems are coming into increasing scientific and management focus. Thermal stress and ocean acidification are suggested to pose the greatest existential threat to MCEs, while many local disturbances are amenable to local management strategies. Increasing knowledge of the distribution and structure of MCEs is a critical first step in management.