AquaMaps is an approach to generating model-based, large-scale predictions of currently known natural occurrence of marine species. Models are constructed from estimates of the environmental tolerance of a given species with respect to depth, salinity, temperature, primary productivity, and its association with sea ice or coastal areas. Maps show the color-coded relative likelihood of a species to occur in a global grid of half-degree latitude / longitude cell dimensions, which corresponds to a side length of about 50 km near the equator. Predictions are generated by matching habitat usage of species, termed environmental envelopes, against local environmental conditions to determine the relative suitability of specific geographic areas for a given species. Knowledge of species’ distributions within FAO areas or bounding boxes is also used to exclude potentially suitable habitat in which the species is not known to occur.
The modeling approach used by AquaMaps was originally developed by Kristin Kaschner and colleagues to predict global distributions of marine mammals (Kaschner et al. 2006). The approach was based on incorporating expert knowledge into an environmental envelope or ecological niche model. The use of expert knowledge compensated for the effects of species misidentifications, effort biases, and the non-representative coverage of large-scale species’ distributions. Such data gaps and problems are widespread in publicly available occurrence data sets that are compiled from different sources.
Theapproach developed for marine mammals was subsequently modified in collaboration with FishBase staff to make it more suitable for a greater range of marine organisms and to make use of data and information available in FishBase and OBIS/GBIF online databases. Display of the maps on the web has been facilitated by the use of C-squares Mapper developed by Tony Rees of CSIRO, Australia.