Comparing on-site and off-site survey data to investigate survey biases in recreational fisheries data

Abstract

Recreational fishing is increasingly included in fish stock assessments globally. Nonetheless, the extent and precision of recreational fisheries data are often limited. Common methods to collect those data are on-site and off-site surveys, both of which are prone to specific biases, whose magnitude is widely unknown. The present study compares data from an on-site access point intercept and a simultaneously conducted off-site diary survey, separately targeting charter boat, boat, and shore anglers in the German Baltic Sea recreational cod fishery to identify specific biases in the data sets. The analyses revealed indications of avidity and recall bias that might influence catch and release estimates. Catch rates and release rates differed substantially between the angling platforms. The catch and release rates of diarists and on-site anglers were in a similar range for every platform, and reasonably precise with standard errors between 0.1 and 0.4 fish per angler and day. Recreational fishing monitoring approaches should include complementary on-site surveys from time to time to control for biases whereby the angling platform should be taken into account. The low explanatory power of commonly collected socio-demographic variables indicated that variables capturing the heterogeneity of angler behaviour should additionally be included in future surveys.

Characterizing the Profile of Recreational Fishers Who Share Their Catches on Social Media

“…among the onsite and online survey could be related to implicit methodological biases as recently highlighted in other studies (Lewin et al, 2021). Therefore, our results suggest that data mined on social media could prove useful to monitor recreational fishing catches of the most frequent targeted species such as the gilthead seabream (S. aurata).…”

“…Moreover, recreational fishers who tend to catch trophy, iconic, or emblematic species were more inclined to sharing catches on digital platforms. Our results also highlighted important differences between onsite and online surveys; these are expected due to their intrinsic biases (Lewin et al, 2021), each of which are discussed in detail for all the variables analyzed. Specific biases that may be important for the interpretation of the results of the different surveys are identified, as well as those related to the validity and use of data mined from digital platforms.…”

“…Firstly, the two sampling methods used are affected by different sources of bias. The online questionnaires were affected by well-known biases of recall and perception (Lyle et al, 2002;Dillman, 2011;Jones and Pollock, 2013;Lewin et al, 2021), as well as coverage-bias (only recreational fishers in possession of a license could receive the online questionnaire), and self-recruitment, as surveys were voluntary (Andersens, 2009). These biases have likely interfered with fishing avidity, HPUE estimations, economic expenditure and catches.…”

“…Data used for this study were provided by the Catalan Institute of Research for Ocean Governance (ICATMAR) that recently began a comprehensive marine recreational fishing monitoring program that includes data collection from on-site surveys conducted along the Catalan coast (north-western Mediterranean Sea, Spain), and from online questionnaires that were sent to license holders. The two methods are used in parallel to minimize data quality issues following previous knowledge on methodological strengths and shortcomings (Pollock et al, 1994;Andersens, 2010;Zarauz et al, 2015;Peramos and Andersens, 2016;Lewin et al, 2021). The combined methodology was first tried in a pilot test conducted in 2019 (ICATMAR, 2021) and was expanded in 2020 to become a long-term monitoring system.…”

Patterns of Live Baitfish Use and Release among Recreational Anglers in a Regulated Landscape

“…The interactive nature of these biases means that implementing survey methodologies to reduce these biases can have the effect of introducing different ones. Responses to our intercept survey implemented at water access sites could have been subject to some recall bias if an angler chose to complete them off site (Tarrant et al 1993) or avidity bias due to the greater likelihood of frequent anglers to be included in the sample (Lewin et al 2021). On the other hand, some research recommends allowing a subsample of directly questioned respondents to anonymously return surveys to the research team (Arrow et al 1993; Leggett et al 2003) to reduce the potential for anglers to feel pressured by the questioner to answer a certain way (Bova et al 2018).…”