Use of Two Alternative Methods to Validate Access Based Creel Probabilities

Trafx car counters and AIS inspections were used to validate creel access probabilities during the 2014 summer creel on Leech Lake. Trafx car counters were placed at each public access during the 2014 summer angling season. Interview data was also obtained from AIS inspectors who were stationed at public accesses during the summer angling season. A Chi square test was used to compare landing frequency among car counters, AIS inspections, and creel interviews. Probabilities were examined for six of the nine public accesses on Leech Lake. Significant differences were observed between car counters, AIS inspections, and creel interviews (P >0.001). High usage accesses were sampled in greater proportion than their actual usage. Differences were greatest on weekend days, morning creel shifts, and in May and September when fishing pressure was highest. Proper distribution of creel sampling effort is critical in access based creels where clerks are not able to sample anglers in their true abundance. Failure to ensure the proper distribution of sampling effort may lead to over or underestimating harvest rates which ultimately affect harvest and yield estimates. The usage of car counters may be used to continually estimate angler distribution and lead to better creel study designs.