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Closed areas to scallop dredging are widely distributed around Shetland, amounting to just under 26 km2 of sea surface area. The areas vary in size from 0.003 km2 to 14.6 km2, the largest accounting for 56.6% of the total area closed around Shetland. This variation is primarily due to the type of externally sourced data (i.e. point data or predicted species bed) used to originally define the extent of the feature. Historically, predicted species beds had been derived from a number of sources and various agencies from a combination of point data and localised bathymetry information. The current study surveyed existing closed areas using a hull mounted multibeam system and groundtruthed with an underwater camera system. Information was imported to GIS in order to create a georeferenced map of the presence of the species of interest, and in particular where they occur in sufficient abundance to consitute a ‘priority feature’ or habitat. Although it is generally accepted that the presence of the species does not inidcate a priority feature at low density and/or small patch size, some debate remains as to what criteria should be met to define the presence of a significant feature; a suggested criteria appropriate to the survey methodology was defined for this study.
For the 20 sites surveyed in detail the predicted species beds, based on or derived from historical data, were not found to be representative of the current distribution of priority features. As a result the corresponding closed areas originally established by the SSMO were either not fully encompassing the UK BAP habitats located at the sites or were not protecting any UK BAP habitats (none present). Of the 20 sites surveyed, 12 were found to have either M. modiolus, maerl, or both; nine of these contained a priority feature but only two had a closed area which completely encapsulated the full extent of the feature. Alteration or removal of the boundaries of the existing closed areas is therefore appropriate and recommendations for this process are included. Further refinement of boundary areas may be warranted after consultation and additional focussed surveys.
Although the surveys illustrate the need for validation of closed areas with high quality acoustic and visual survey data, the exercise provides a practical and successful industry-science approach to the establishment and incremental development of local spatial management plans. In the absence of detailed maps for entire sea areas, which rarely if ever exist, the use of historical data and local knowledge provides a basis for the focussing of survey resources. The use of acoustic surveying technology, such as multibeam, proved highly cost effective in mapping priority habitats. Multibeam surveys cover large areas of seabed relatively quickly, producing good quality maps to a high degree of accuracy, and as with this example, this is ideally suited to management plans based on ‘physical’ features (biogenic reefs) rather than biotopes. However, broad scale mapping of this type may inform the likely presence of biotopes, which can be confirmed by more cost and labour intensive methods if required.
Although the science-industry partners acknowledge that the methodology of using historical data and local knowledge may not result in absolute protection of priority features during the first iteration, as is the case here, it was deemed preferable to establish a locally agreed framework, dialogue, and options for further refinement toward this goal than to leave the conservation of priority features unaddressed or awaiting investment in large-scale, holistic marine surveys. Direct stakeholder involvement in the process installed belief that clear and unambiguous science would rectify issues at a later date, and therefore fishermen agreed to voluntary closures of these areas before they were made statutory. As the Scottish Government currently empowers the SSMO to make changes to the spatial management plan for shellfisheries in the waters around Shetland by means of a Regulating Order, further surveys and consultation will increment toward more fine-scale improvements to the appropriateness of the plan well into the future.
|Publisher||NAFC Marine Centre|
|Number of pages||166|
|Publication status||Published - 2013|
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Richard L. Shelmerdine (Speaker)9 Jul 2019
Activity: Talk / Presentation / Podcast / Webinar › Oral presentation
11 Feb 2016
Activity: Other › Types of Public engagement and outreach - Public lecture/debate/seminarFile