SeaRover 2017 Deep Water Reef Habitat & Species Video Analysis Report.

SeaRover2017 ROV (Remote Operated Vehicle) Deep Water Reef Habitat & Species Video Analysis report produced by Rebecca Ross, Giulia La Bianca, and Kerry Howell (University of Plymouth) and Commissioned by Marine Institute, Rinville, Oranmore, Co. Galway. This report describes ROV Holland (Marine Institute, Ireland) underwater video data collected during SeaRover 2017 research cruise onboard Irish Lights Vessel Granuaile. Report contains 329 pages. SeaRover stands for Sensitive Ecosystem Assessment and ROV Exploration of Reef. This survey was commissioned by the National Parks and Wildlife Service (NPWS), funded by the European Maritime and Fisheries Fund (EMFF), and coordinated and led by INFOMAR (Integrated Mapping for the Sustainable Development of Ireland?s Marine Resources) and Ireland?s Marine Institute. SeaRover 2017 aimed to map the distribution and abundance of Ireland?s biogenic and geogenic reef along the Ireland?s continental margin from Porcupine Bank to the northern border with UK waters. This report provides a detailed ecological analysis of the seabed videos acquired over the 50 ROV dives undertaken during this survey. This study revealed the following diversity along the surveyed parts of the seabed: 367 putative species were identified from HD video footage supplemented by high resolution imagery (using an operational taxonomic unit (OTU) system as it is not always possible to identify fauna to species level); 137 OTUs were identified in the most species rich dive (Dive 488/ Transect 20); 34 OTUs were identified in the least species rich dive (D470/ T24); 66 OTUs were identified on the average dive; 23 OTUs were found in more than half of the transects; 56 OTUs were found in only one transect. 101 potential biotopes were identified in line with the Marine Habitat Classification for Britain and Ireland (v.15.03), of which: 58 are existing biotopes, un-altered from the MHCBI listing; 37 are minor variants of existing biotopes; 5 are potential new biotopes, or variants which may warrant becoming new child biotopes; transitional/co-occurring biotope complex was also encountered multiple times which may warrant future consideration as a biotope of its own. None