Estimating angling effort and participation in a multi-user, inland fishery in South Africa

Angler counts, on-lake interviews and a household survey were used to estimate angler effort and participation in Lake Gariep, South Africa's largest inland water body. Annual fishing effort was estimated from instantaneous counts at 16392 angler day⁻¹ yr⁻¹. Recreational and subsistence anglers contributed 41 and 59% to the total annual fishing effort, respectively. Household surveys in lakeshore settlements estimated that ≥914 anglers fished the lake and minimum daily fishing effort in one of the fishing areas assessed was 77 anglers. As a result of recall bias, these estimates were almost twice as high as those determined by direct counts. A low cost method of assessing participation by applying a mark-recapture model to the proportion of anglers whom had been previously interviewed during eight bimonthly sampling events was tested. The model converged in three of four applications (2 areas x 2 sectors). The mark-recapture method revealed similar numbers of anglers to the estimate of regular anglers (fishing 1-3 times a week) from the household survey and was considered an appropriate estimator for the number of subsistence anglers. Regardless of the assessment method the results show that the resource is of importance to subsistence livelihoods, which is an important management consideration in future fisheries development and rights allocation processes.