Diver-led visual surveys at 11 mesophotic reef sites around Bermuda found that high densities of lionfish were associated with both higher abundances of prey fish and higher prey fish biomass. However, the influence of seawater temperature was found to have the strongest effect on lionfish distribution, with higher lionfish densities recorded at sites with lower bottom temperatures. These results suggest that cold-water upwelling may result in higher abundances of prey fish and lionfish.