Bibliography: p. 109-122.This thesis explores the relationships between commercial data and those obtained from research surveys in an attempt to broaden the database available for management, and to cover seasonal and inter-annual changes in density estimates of Cape hake (Merluccius capensis). It also attempts to explain hake variability of in terms of environmental indices based on satellite remote sensing, carefully chosen to reflect underlying oceanographic processes. The influence of various factors on catch rates (CPUE) is investigated using a general linear model