Community and genetic patterns of mesophotic fishes

Mesophotic environments, occurring between 40-150m, are too deep to study on open circuit SCUBA and too shallow to invest money to study with ROVs. Thus, this environment remains a largely unexplored region of the marine realm. I am interested in the distribution of fish assemblage between shallow and mesophotic environments and the mechanisms that facilitate these patterns.

Additionally, mesophotic environments are thought to act as a refuge during glacial cycles were 92% of the shallow habitat disappears. These environments may act as a refuge against disturbances that occur in shallow habitat and therefore becoming a source populations to seed and repopulate shallow populations. For my research, I am interested in understanding the degree of connectivity for fish populations across a vertical gradient and extending from shallow habitat to mesophotic environments. 

My CCR training has has proven to be a value skill which has allowed me the unique opportunity to personally explore mesophotic ecosystems. To date, my deepest dive is 330 feet (~100 meters) and my longest continuous submerged dive has been more than 4.5 hours. Many of the species I encounter at these depths are unknown to science and despite the steady increase in research related to this environment, the mesophotic environment remains largely understudied. 

Conducting fish surveys in Ponhpei, Federated States of Micronesia


Photo: Conducting fish surveys at mesophotic depths (250') at Pohnpei, Federated States of Micronesia. Diving on closed-circuit rebreathers lets us dive to deeper depths and stay underwater for up to 4 hours or more has allows us to begin exploring mesophotic ecosystems (150-500'). These areas are too deep for SCUBA and too shallow for ROV's, thus we are pioneers in unexplored habitat. This is exhibited by new species of marine life being discovered on almost every dive that we do to mesophotic depths. Photo credit: Robert Whitton