Publication Abstract

A System for the Spatially Explicit Modelling of Communities of Class-Structured Benthic Organisms

Beecham, J.A*. Platts, M.D. Jennings, S.

Benthic communities are determined by structure (bathymetry, currents, temperature and seabed type) and by the interactions with food-sources, disturbance and predation which are likely to be non-uniform in space.  A model was constructed where spatiotemporal data could be input as a GIS layer and interact with the functional relationships for colonisation, competition, predation, growth mortality and spawning. These functional relationships can be specified as add-on functions and applied to a complex, spatially-organised, functional group by means of operator overloading. By encapsulating the low level representation of spatial data within the functional group, the model is efficient in its memory access patterns. The size-based structuring which enables predation and competition between functional groups to be expressed is combined with an orthogonal variable used to express the proportion of calcified material, such as shell. By expressing the coefficients of biological process as a range of values determined by a function the data layers could be used to modify the parameters of the biological processes. An example is shown where a GIS layer describing frequency of beam trawling is combined with an empirical model of mortality resulting from disturbance, to demonstrate the effect of beam trawling on growth and biomass of benthic infauna and epifauna communities. The data layers can also be used to represent information from linked models such as ERSEM, either online through coupling, or offline as a netCDF file.

Reference:

Beecham, J.A*. Platts, M.D. Jennings, S. (2010) A System for the Spatially Explicit Modelling of Communities of Class-Structured Benthic Organisms. ICES CM 2010/ Session L