Computer-Assisted Map Analysis of Marine Ecosystem Information

Computer-assisted map analysis techniques represent a useful means for comparing and evaluating spatial and temporal distribution patterns of populations and their environments in marine ecosystems. This paper describes considerations in the preparation and analysis of zooplankton data. A cartographic data base of the continental shelf off the northeastern United States was developed and used to demonstrate computer-assisted map analysis techniques for investigating spatial patterns in very large ecosystems. All mapped data were spatially registered by conversion of latitude and longitude coordinates to rotated Lambert conic conformal rectilinear coordinates and stored in grid format of approximately one hundred square kilometers per cell. Continuous spatial distributions of the ship survey data were created by a weighted distance interpolation technique. The analysis of these data included the generations of statistical summaries and maps describing the distributions of three zooplankton species and the gradients of their abundances.