Bridging the temporal gap: Continuous and cost-effective monitoring of dynamic recreational fisheries by web cameras and creel surveys

Abstract

We describe a cost effective method of continuously monitoring relative trends in recreational effort and harvest, based on web camera imagery and interview data provided by a concurrent low intensity creel survey. The number of boats returning to three boat ramps in separate regions on the north eastern coast of New Zealand’s North Island fluctuated over a ten year period between 2004–05 and 2013–14. The most pronounced change occurred in the Hauraki Gulf, where most recreational fishing occurs. Web camera monitoring detected a 34% decline in the number of boats returning to one of the busiest ramps in the Hauraki Gulf over a three year period between 2011–12 and 2013–14, which was mirrored by a 58% decline in snapper catch rates over the same period. The combined result was a 71% decline in the weight of snapper landed annually at the monitored ramp over this three year period, which was far more rapid than anticipated given differences seen between harvest estimates provided by infrequent large scale surveys in the past. Trends in effort and harvest derived from data collected at a small number of ramps will only have utility, however, if they reflect trends in the wider fishery. The relative difference in snapper harvest estimates provided by aerial-access surveys of the entire Hauraki Gulf fishery in 2004–05 and 2011–12, closely matched the difference in the harvest landed at the high traffic ramp that was monitored in the Gulf during these years. This independent confirmation of relative trends inferred from combined web camera and creel survey monitoring at a small number of sites has further highlighted the need to continuously monitor recreational fisheries, which are potentially far more dynamic than previously thought. We discuss strategies that we have progressively developed to minimise the cost of monitoring these recreational fisheries and how they could be applied to continuously monitor recreational fisheries elsewhere.