Research and analysis

Semi-quantitative methods for fisheries classification

A project which has been carried out to evaluate the use of semi quantitative methods for fish stock assessment for use in the Fisheries Classification Scheme.



This report discusses the various approaches to calibrating semi-quantitative methods, and critically assesses a number of regional calibration exercises undertaken by the Environment Agency and its predecessors. Three areas for improving these methodologies are identified: 1) a correction for different types of river habitat, 2) the assessment of classification errors and 3) a refinement of the statistical-procedures used.