Raster

The requirement to display sensitive areas relating to the life history of commercially important fish species in British waters is well recognized. Sensitive areas have previously been described as spawning and nursery grounds. Here we consider only areas where there is evidence of aggregations of 0 group fish and/or larvae of key commercial species. 0 group fish are defined as fish in the first year of their lives. These fish sensitivity maps were originally generated to provide a spatial and temporal description of where physical damage could potentially occur to fish species at sensitive stages in essential habitats of their life cycle. Sources of damage in this context referred to seismic surveying conducted by the offshore Oil and Gas industry during their site investigations. In addition to the acoustic energy that the seismic survey activities generate, we should now add other percussive impact noises from pile driving seabed foundation pins into the seabed, such as those required for offshore renewable energy sites. The spatial location of these fish life history events and their potential interaction with offshore industries can heavily influence the planning, costs and delivery of these offshore developments. It is imperative that these maps reflect the current extent of these areas.

This layer depicted modelled probability of Haddock in year 0 group.

Topographical wave exposure indices allow objective assessment of the degree of wave action at coastal sites. We present a grid-based method for rapidly calculating indices at fine spatial resolutions along whole coastlines, and evaluate the power of candidate indices in predicting composition of rocky shore communities. The method has 3 stages: (1) a grid is created from a vector-based digital coastline using geographical information systems (GIS) software; (2) for every coastal cell, wave fetch is determined as the distance to the nearest land cell in 16 angular sectors, using coarse-, medium- and fine-resolution searches of the surrounding cells up to a distance of 200 km; (3) wind energy (average wind speed and proportional occurrence) in each sector is calculated for nearby coastal sites. We calculated the average fetch in each sector (F) and the sum of products of fetch and wind energy (W). A total of 57 species were surveyed at 185 sites in west Scotland for determination of trends with wave indices. Average wave fetch with a 200 m scale grid explained >50% of the variation in the first principal component of the species-sites abundance matrix, with shore extent explaining another 10%. Incorporating wind data in the indices had a negligible effect on predictive power. Species diversity explained 61% of the variance in the second principal component and declined from low to high pelagic primary productivity. Separating direct physical effects from biological effects, such as food supply or grazing could potentially help us better understand the processes structuring biological communities on rocky shores.

For more information see https://www.sams.ac.uk/people/researchers/burrows-professor-michael/