Investigations into the biogeography of the bathyal deep sea

Abstract

The determination of properly delimited biogeographic regions is becoming increasingly urgent as conservation efforts strive to prioritize the protection of areas with the highest diversity and/or most vulnerable fauna. Marine biogeographic provinces have been described for shallow coastal waters (<200 m), the abyss, and the hadal; however, biogeographic provinces for bathyal depths have yet to be proposed based on species distributions. In this study, global records of cnidarian distributions were analyzed using two separate biogeographic methods – hierarchical cluster analysis and network theory – to investigate the biogeography of the bathyal and provide the first global biogeographic framework of benthic bathyal provinces based on biological data. A finer scale assessment of a region that has been relatively well sampled, the Northwest Atlantic, reveals that there may be additional variations in benthic assemblages within a province due to differences in temperature, salinity, proximity, and substrate.