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SeaRover (Phase 1) Assessment of Fisheries/Habitat Interaction on Offshore Reefs

As part of the European Habitats Directive (EC 92/43/EEC), Member States need to take measures to avoid deterioration of protected habitats. Ireland is carrying out extensive mapping surveys of offshore reefs to evaluate status and introduce conservation and management measures in proportion to status and pressures from fishing. This study has been identified as high priority by the Department of Culture, Heritage and the Gaeltacht (DCHG) for the marine environment to fulfil Ireland’s obligations under the Habitats Directive.

Under the Habitat’s Directive reporting requirements, Ireland has reported to the European Commission that Annex I habitat reef is in unfavourable/bad status in its waters, and this is primarily arising from fisheries-related issues in the offshore resource. Reviewing habitat fisheries interaction and arising conservation requirements is of high priority for offshore reef habitats. Existing information and datasets on Ireland’s deep reef habitat have been collated to assess the status of reef in water greater than 200m and evaluate sensitivities of deep reef habitats as part of a commissioned desk study by DCHG.

Spatial information on reef habitats were overlaid with activity data from fishing vessels using different gears to link potential impact with habitat sensitivity and identify data deficiencies.

The desk study on reef habitats and spatial fisheries overlay formed the basis of reef habitats to be surveyed as part of two 3 week reef surveys in 2017 and 2018 respectively. The surveys use Ireland’s remote operated vehicle Holland 1 to collect video footage and stills along fixed transects for detailed investigation and mapping of Annex 1 reef habitat. Areas of focus are reefs with high conservation value and low interaction of fishing effort. In selecting new sites to be surveyed, the following aspects were taken into account:

  • Data availability for pre-screening
  • Level of fishing pressure, focussing on low impact sites
  • Geographical distribution in relation to existing designations and certain geomorphological features including canyons and escarpments

The 2017 survey also re-visited an existing SAC designation to monitor signs of impact and recovery along transects originally surveyed in 2009. This data will be used to evaluate detection of change and effects of mitigation in designated sites.

The project is carried out in close collaboration with the Marine Institute (Fisheries Ecosystem Advisory Services and Advanced Mapping Services), INFOMAR, the Geological Survey Ireland and National Parks and Wildlife Services, and their relevant parent departments to ensure appropriate staff expertise is provided and project objectives are achieved. Additional financial contributions are made by DCHG.


The project is carried out in two phases. Phase 1 runs between 2017 and 2018 and includes 2 offshore mapping surveys. Phase 2 will run between 2019 and 2020.

Project Outputs:

The project is ongoing. The expected outcomes are listed below:

  1. Assessment of Irish National Seabed Survey and compiled reef habitat data in Irish offshore waters to identify high likelihood of reef distribution
  2. VMS overlay of vessels using bottom impacting gears
  3. Proposed survey design based on fisheries habitat interaction of Irish reef habitats >200m
  4. Survey reports of two 3 week ROV habitat mapping surveys
  5. Data output of each reef survey
  6. Data dissemination via web interphase
  7. Outreach material relating to the above
Expected Benefit:

The video data acquired during the surveys will help to map the extent of sensitive ecosystems in Irish waters and broaden our ecological understanding of these leading to the sustainable management of Ireland’s marine biodiversity. It will further support the:
• Characterisation of offshore reef habitat in the Irish EEZ at selected sites to include existing designations and areas of low fishing impact and limited data availability
• Evaluation of fishing impact on reef habitat at selected offshores sites
• Provide input data to support reporting requirements for Ireland under the Habitats Directive and the Marine Strategy Framework Directive

Further Information:
Contact David O’Sullivan, Marine Institute, Rinville, Oranmore, Co. Galway at
Project Cost - Projected:
€1,400,000 (with €200,000 contribution from DCHG)
Project Status: