Mapping habitats and biotopes from acoustic datasets to strengthen the information base of Marine Protected Areas in Scottish waters:
Mapping habitats and biotopes from acoustic datasets to strengthen the information base of Marine Protected Areas in Scottish waters
The objective of this project was to generate seabed habitat maps for locations coinciding with Scottish MPA proposals with full coverage acoustic datasets to as detailed a hierarchical level as possible within the Marine Habitat Classification for Britain and Ireland (version 04.05), also known as MNCR classification, (Connor et al 2004). The acoustic data were at various stages of processing and interpretation, therefore the mapping of habitats and biotopes in some areas have required a greater amount of work to reach the same level compared to other areas.
The constituent polygons within the habitat/biotope maps are labelled to an appropriate level of the Habitat Classification and translated to the corresponding EUNIS code.
In order to generate seabed habitat maps for the areas the data associated with each area were required to undergo some preliminary preparation and processing in order to ensure suitability and compatibility with the mapping methodologies employed.
The data were then processed using several techniques: a top-down rule-based approach was adopted based on the methods developed by MESH, UKSeaMap and EUSeaMap, which utilised the updated seabed substrate information provided by BGS. In addition a bottom-up approach was taken to utilise the recently acquired point sample data and multi-beam bathymetry and backscatter data sets; this process took an object-based approach supplemented by supervised classification and categorisation.
Three maps for each location have been produced. The level of habitat detail which could be mapped was restricted to level 3 & 4 of the EUNIS classification with associated metadata and peripheral supplementary data to aid in future analysis and interpretation. A confidence assessment using the MESH confidence assessment method has been undertaken for each habitat map produced and certainty of classification maps accompany each habitat map also.
The assumptions and limitations of the data and the techniques and processes used to produce the maps are discussed to aid understanding and application of the maps.
These maps make an important contribution to the evidence base for the presence and extent of MPA search features underpinning the identification of MPA proposals in Scotland’s seas.