Effect of recall period on annual freshwater fishing effort estimates in New York


Nancy A. Connelly, 126 Fernow Hall, Cornell University, Ithaca, NY 14853, USA (e-mail: nac4@cornell.edu)


Abstract  Recall bias can influence estimates of fishing effort, with a general trend toward overestimation as the length of the recall period increases. Concern that recall bias may be affecting annual freshwater fishing effort estimates in New York led to the collection of effort data from three angler surveys during 2007 instead of one survey at the end of the year. However, to check for this potential bias and the impact that a change in recall period might have on comparisons with past surveys, a parallel survey with a 12-month recall period was conducted. For the overall state-wide estimate of fishing effort, the estimate from the three-phase survey was slightly greater than from the 12-month recall survey (the opposite of what was hypothesised). For the major water bodies, the differences were mostly significant but not always in the same direction between the two survey methods. Different results from one study compared with many others do not mean that past recommendations for shorter recall periods should be abandoned. However, the strength of this study – that the implementation methods (i.e. mail surveys) were identical – leads one to be more sceptical of past results.