Evaluation of Vehicle Counters for Monitoring Angler Effort on Small Inland Lakes

Angler effort can affect the quality and long-term sustainability of fished. Angler effort is typically estimated using creel surveys, although surveys are rarely conducted on most lakes due to costs and logistics. When creel surveys are possible, small sample sizes (few interviews) may lead to large variance and poor confidence intervals associated with estimates of effort. The objective of this study was to determine if use of low-cost remote vehicle counters can be used to estimating trends in angler effort. During the spring of 2015, vehicle counters (n = 40) were buried at boat ramps throughout the state of Wisconsin.  We compared vehicle counter results to boat ramp use determined from trail cameras deployed at 14 study lakes. Linear regression was used to evaluate relationships among estimates of boat ramp use (i.e., effort). Vehicle counters explained on average 77% of the variation in the number of boats using each lake. This suggests vehicle counters can be used to remotely monitor trends in angler effort on some water bodies. Vehicle counters could provide more accurate estimates of temporal trends in angler effort through continuous monitoring at many lakes compared to sporadic counts conducted during traditional creel surveys.