Discovering the deep: Exploring remote Pacific marine protected areas

The 2017 Discovering the Deep expedition provided the first glimpse of the deep-sea geology and ecology of the deepwater regions of Swains Island, the Howland and Baker Islands Unit of PRIMNM, Phoenix Islands Protected Areas (PIPA), and the Tokelau Region (Figure 1). Prior to this expedition, virtually no visual reconnaissance had been conducted in any of these areas below scuba diving depths.

ROV dives during this expedition focused on deep-sea corals, sponges, and fish assemblages, with particular interest in locating high-density and high-diversity biological communities. Indeed, nine high-density biological communities were documented out of the 19 dive sites explored. Many of these observations were new records for these regions, and several likely yielded species new to science. Acoustic mapping operations covered more than 47,000 km2 of seafloor. The collected imagery and specimens will improve our understanding of the distribution of deep-sea corals and sponges, the ages of the seafloor features, and overall geological context of these different environments.