A Spatial Representation of the Nearshore Ecosystem for Species-Habitat Studies

To support the development of critical habitat designations, species recovery strategies, and habitat-based stock assessments, comprehensive spatial maps of the physical and biological characteristics of the nearshore (0 – 50 m) region are required. This region – termed the ‘white strip’ by marine geologists because of the lack of physical data – is dynamic, highly variable, and difficult to access. Data collection is therefore patchy and expensive. With few exceptions, the habitat analyses conducted in this ecosystem are generally done over small spatial extents, at a high resolution.We have been working to develop the concept of habitat patches (HaPs) to integrate the available physical data sets describing this region. These include depth, fetch, tidal energy, and bottom type information from dive and aerial surveys, acoustic soundings, and grab samples. The resulting spatial coverage is an integrated, variable resolution, comprehensive representation of the nearshore ecosystem based on the best available data. The approach is updatable, thus accommodating improvements in data quality and availability. We have defined HaPs for the Strait of Georgia, British Columbia, Canada, and biological validation has confirmed they provide a reasonable representation of the nearshore. The spatial framework is suitable for attaching various physical and biological data, and analyzing spatial correlations. Future work will include expanding the framework to the entire BC coast and developing suitability maps for nearshore species of interest.