Fish species are sometimes classified as

‘schooling’ (such as herring, anchovies and tuna) or ‘searching’ (non-schooling) classes, with the former being defined by the tendency to ‘school’ in large numbers. In the text we specified fishery harvest by the equation H = H(E, S). For some species, the level of stocks has a much less important effect on harvest, and so (as an approximation) we may write H = H(E). Is this more plausible for schooling or searching species, and why?

Problems marked with an asterisk * require that the reader either construct his or her own spreadsheet program, or adapt the file exploit5.xls.