THE USE OF NUMERICAL METHODS TO DETERMINE BENTHIC DISTRIBUTION PATTERNS FROM DREDGINGS IN FALSE BAY

Abstract

This pilot study tests numerical grouping techniques on data obtained from dredge sampling to see whether such methods might be useful tools in the analysis of marine distribution patterns and their causes. Problems of dredge sampling are mentioned and a system for coding dredge sample data is described. The Czekanowski coefficient is used in a normal analysis to form groups of samples and these show some agreement with the grounds described by Morgans (1962). The information statistic is shown to be useful as an objective method for limiting the size of groups. The method of McConnaughey (1964) is used in inverse analysis to form groups of species, and improvements on his method of presenting results are suggested. With some exceptions, the results are in general agreement with those of normal analysis. It is concluded that methods of similarity analysis are likely to be useful for the analysis of marine distribution patterns, but caution is needed in the choice of data for analysis. Further work is in progress to get more detailed results.