Shedding light on mesophotic coral ecosystems

Study presents several decades of data on Hawaiian mesophotic coral ecosystems 

Research divers place a dome over a set of corals 89 m deep as part of an experiment to determine coral feeding patterns

Research divers place a dome over a set of corals 89 m deep as part of an experiment to determine coral feeding patterns. The HURL submersible Pisces V can be seen in the background. Photo by RL Pyle licensed under CC BY 4.0.

Most coral reefs are found in shallow waters of tropical regions, but even at depths ranging from 30 to 150 meters and sometimes even deeper so-called mesophotic coral ecosystems (MCEs) exist. Here, the levels of light are low, explaining the name “meso” (meaning middle) - “photic” (meaning light).

In an interdisciplinary study spanning more than two decades, researchers characterized MCEs in the Hawaiian Archipelago using a vast and diverse set of methods to provide insights into structure, composition, ecological dynamics and managements needs of MCEs in general. Their methods included field operations of photo documenting and sampling both by trained divers, remote-controlled devices and automated sensors.

Biodiversity surveys documented or collected more than 72 species of frondose macroalgae, ten species of scleactinian corals, 200 invertebrate specimens (of which three quarters remain unidentified), and also four undescribed species of fishes.

The researchers deposited voucher specimens to the Bernice P. Bishop Museum and documented occurrences in a dataset available on GBIF.org.

Pyle RL, Boland R, Bolick H, Bowen BW, Bradley CJ, Kane C, Kosaki RK, Langston R, Longenecker K, Montgomery A, Parrish FA, Popp BN, Rooney J, Smith CM, Wagner D and Spalding HL (2016) A comprehensive investigation of mesophotic coral ecosystems in the Hawaiian Archipelago. PeerJ. PeerJ 4: e2475. Available at: https://doi.org/10.7717/peerj.2475.