Presenter: Eryn Faggart (College of Charleston)

Description:
Karin Seamount, located 1200 km off the southwest coast of Hawaii and 130 km northeast of Johnston Atoll, is part of the Pacific Remote Islands Marine National Monument. This region sustains a high diversity of marine life and is thus relevant to modern scientific exploration in making informed resource management decisions. In September 2015, NOAA OER mapped Karin Seamount during the Hohuna Moana: Exploring Deep Waters off Hawaii to identify deep-sea coral and sponge communities and relate these findings to the area’s geomorphology. Karin Seamount Range has a linear configuration composed of flat-topped seamounts and peaked ridges. Three main study sites were examined - Karin Guyot, Karin Ridge and Southeast Seamount. The sites exhibited steep, rocky-embankments consistent with the presence of deep-sea corals. Operations utilized the NOAA Ship Okeanos Explorer’s multibeam sonar deep water mapping system and high definition video collected during EX1504 Leg 4 by the ROV Deep Discoverer. In 2015, EX1504L4-Dive 10 was made along a Karin Seamount guyot. Diverse coral and sponge aggregations were observed at depths greater than 1,800 m in association with smooth pillow lava formations and sparse sediments. A comparison was also made between Karin Seamount Range and Seamount Souteast using similar methodology and ground-truth data provided by ROV dives. In 2017, EX1706-Dive15 revealed a hard-bottom substrate composed of abundant aggregations of corals and sponges located at a max depth of 2027 m. Utilizing data collected from initial ROV dives, an analysis was conducted to determine the geomorphological characteristics that potentially support various benthic habitats. Subsequent results were summarized through approximation of deep-sea coral aggregations along Karin Seamount.