Abstract. This paper collates the results of five surveys which were made to determine the average catch of anglers not making a return at game fisheries. This pilot study shows that the average catch per licence/permit () may be estimated from the average and the proportion of unprompted returns, (mu) and (pu) respectively, by the empirical equation , for trout and sea trout, Salmo trutta L. Salmon, Salmo salar L., catcrl’rates may be best estimated from . Typical values for United Kingdom waters are tabulated for recent seasons. Rod catches of stillwater and migratory fish closely follow the Negative Binomial distribution. Their means and variances are shown to be related empirically by Taylor's power law: for daily records of stillwater trout and migratory fish, and for annual records of salmon, and of sea trout. A method of estimating the expected frequency distribution of catches at any water is shown. The distribution is truncated where the nil catches are not recorded and is censored where the bag is limited; here a microcomputer was programmed to compute the estimates of the mean and variance of the catches and to print the full distribution.

Abstract. An assessment of the angling performance of a small put‐and‐take/or release fishery slocked with rainbow trout, Salmo gairdneri Richardson, at a density in the range 345–565 fish/hectare (140–230/acre) showed that the correlations of mean daily and weekly catch per unit effort with population of fish were low and of uncertain significance at the 5% level. A pilot comparison with other fisheries indicates that the annual mean catch per full day and the annual mean population density may be related by the equation Catch/full day = 0·74 Fish/hectare0·33 The roles of catch per unit effort and frequency distributions in the estimation of fish abundance are discussed.