The SeaRover Project
A requirement exists to quantify the abundance and distribution of offshore biogenic and geogenic reef habitats in Irish waters to fulfil Ireland’s legal mandate and to generate baseline data from which appropriate monitoring systems can be established. To address this an extensive offshore reef survey of Ireland’s Northwest Continental margin 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 and Ireland’s Marine Institute.
The objectives of the survey were to implement the EMFF’s Marine Biodiversity Scheme - Natura Fisheries by mapping offshore reef habitats with a view to protecting them from deterioration due to fishing pressures. The reef project aligns with sub-article 6.2 of the Habitats Directive (EC 92/43/EEC) which requires member states to take measures to avoid deterioration of protected habitats.
A survey, Sensitive Ecosystem Assessment and ROV Exploration of Reef Habitat (SeaRover), took place in July 2017 aboard the ILV Granuaile equipped with the Marine Institute’s remotely operated vehicle (ROV) Holland 1 and a multidisciplinary team of scientists to observe seabed features and biological associations along the northwest continental shelf. The Holland 1 employs high-definition (HD) camera, various composite video feeds and a robotic arm to facilitate sample collection. The primary scientific objective was to map the distribution and abundance of geogenic and biogenic reef habitat along the northwest shelf edge of Ireland’s continental slope with HD video. Secondary objectives included the collection of biological samples for genetic and population analysis and the collection of sediment cores for ground-truthing seabed mapping data and analysis of micro-plastics within deep-water sediment.
Survey transects were pre-selected following a consultation process between the Marine Institute and the National Parks and Wildlife Service. Selection criteria included depth range, areas of highly sloping terrain, geographical spatial discreteness, historical fishing activity, historical scientific studies and the presence or absence of certain target geomorphological features which included, canyons and canyon walls, gullies, escarpments, ridges, carbonate mounds and cobble fields.
A total of 50 transects were surveyed. The vessels travelled 1900 km, 127 hours were spent sampling and recording HD video on the seabed. The ROV travelled 135 km vertically and collected 147 biological specimens and 49 sediment samples. In addition the survey:
- Discovered previously unknown Vulnerable Marine Ecosystems (VMEs) under UN Charter consisting of xenophyophores (large unicellular organisms) and sea-pens.
- Identified biologically sensitive Annex 1 reef-forming, cold-water coral species (Lophelia pertusa and Madrepora oculata) at numerous locations.
- Recorded a third species of cold-water coral, Solenosmilia variabilis forming reefs at depths previously unrecorded (>1600m).
- Explored habitats previously undocumented on Ireland’s north-west continental shelf e.g. canyons, underwater sea-mountains, steep cliff faces and rock-overhangs and an escarpment feature over 160 km during 4 separate dives.
- Provided biological samples to the Marine Biodiscovery programme at NUI Galway and the DeepLinks project at Plymouth and Oxford University to study the ecological diversity of the North Atlantic Ocean.
The findings of the SeaRover survey have contributed to the provision of conservation objectives for the offshore Special Areas of Conservation (SAC) work carried out by NPWS. Additionally the findings will ensure the Department of Agriculture, Food and Marine (DAFM) have fulfilled their obligation to map vulnerable fisheries resources. The survey data acquired improves our understanding of the extent of sensitive ecosystems in Irish waters and underlying geomorphology and it broadens our understanding of the ecological requirements for these environments in support of sustainable management of Ireland’s marine resources. Furthermore, it establishes a need to build on the data collected to date, to help target future mapping of reef habitat, and commit to further study in other areas of Ireland’s offshore. This will ensure the availability of comprehensive biological baseline datasets critical to the formulation of future policy on the management and conservation of Ireland’s deep-water resource.