Previous work in Bermuda on mesophotic reefs has been limited to video surveys conducted with ROVs, however none of these included surveys of fishes and specimen collections were only performed to a maximum depth of 40m.

Recent surveys of lionfish and prey fish on deep reefs in Bermuda found thriving communities of fish and coral species at depths 45-60m. Furthermore, collaborations with a team from the California Academy of Sciences have documented range expansions for 29 fish species in Bermuda. In other regions, explorations and genetic analyses have revealed new species at depth and thus the potential exists for rare and novel species to be identified on mesophotic reefs in Bermuda as well.

In Bermuda, deep reefs are easily accessible, and corals surviving in these zones are at their latitudinal and bathymetric limits, making Bermuda an ideal location in which to study these unique ecosystems. This project aims to increase our understanding of reef fish and coral biodiversity, identify rare and novel species, and contribute to impact assessment and control of invasive lionfish on mesophotic reefs. Surveys are conducted using a combination of open-circuit SCUBA, closed-circuit re-breather, and mixed gas technologies (NITROX and TRIMIX) at 6 reef sites ranging in depth from 45–65m.

Survey analysis and interpretation include: comparisons of distribution and abundance of various coral and fish species at depth across the platform; density and distribution of lionfish populations across deep sites and compared to previous results; and identification, cataloguing, and deposition of collected species. From these data, biodiversity hotspots will be identified, lionfish densities estimated, impact of lionfish on fish communities examined, and rare species documented.

This work is funded by the Research Conservation Committee of the Bermuda Zoological Society. The key themes are developing data on biodiversity and control of an established invasive species, and results will thereby contribute to the management and conservation of coral reef ecosystems.