Corroborating effort and catch from an integrated survey design for a boat-based recreational fishery in Western Australia
Introduction
Recreational fishing has social and economic benefits to the community (Pita et al., 2018), but can take a substantial proportion of fish stocks (Cabanellas-Reboredo et al., 2017; Zischke et al., 2012) and have significant impacts on fish abundances and habitats (Font and Lloret, 2014; Lewin et al., 2006). For many recreational fisheries, sustainability of stocks requires estimates of recreational catches to be considered in stock assessments and for fishery management decisions (Griffiths and Fay, 2015). For some multisector fisheries, estimates of recreational catches are needed for acceptable allocation of the resource between commercial and recreational sectors (Ryan et al., 2016). However, to achieve this, representative and comparable catch and effort information is required for both sectors.
Unlike many commercial fisheries that have mandatory reporting, the collection of catch and effort data in recreational fisheries often relies on either off-site surveys (e.g. diary, mail, and phone) or on-site surveys (e.g. access point, roving, and aerial) (Lyle et al., 2010; Hartill et al., 2012; Rocklin et al., 2014; Wynne-Jones et al., 2014; Teixeira et al., 2016; Bellanger and Levrel, 2017). Advantages of off-site surveys over on-site surveys include coverage of larger geographical areas at lower costs and the ability to survey a larger number of fishers. They also have the ability to collect data for fishing at any location and any time of the day, including night-time fishing. A disadvantage is that they rely on self-reporting by fishers and independent verification of the quality and legitimacy of recall data (Ashford et al., 2010; Dorow and Arlinghaus, 2011; Hartill and Edwards, 2015; Roach et al., 1999). On the other hand, on-site surveys provide accurate information about fishing activity for the locations and time periods covered by the survey, including the harvest and biological characteristics of retained fish, which are directly observed and measured by trained interviewers (Pollock et al., 1994). In many countries, off-site survey methods are predominantly used in national or statewide recreational fishing surveys, in particular, for fisheries with a licence registry, while on-site surveys are usually used at smaller spatial scales for geographically defined fisheries or specific fish species (Barbieri et al., 2017; Hartill et al., 2012; Strehlow et al., 2012). However, the advantages and disadvantages for the different approaches need to be considered for achieving robust and cost-effective survey data, which is the goal for fishery researchers in many jurisdictions.
Development of robust and cost-effective surveys is in demand for long-term monitoring of recreational fisheries globally (Bellanger and Levrel, 2017; Ma et al., 2018; Pita et al., 2017). The trade-offs considered for developing survey methods are often the sample size, level of sampling intensity and cost of an appropriate survey method (Georgeson et al., 2015). Probability-based surveys provide a means of estimating sampling error, and thus the precision or uncertainty associated with estimates. However, bias from non-response and sampling errors which are difficult to measure can influence the accuracy of estimates. The use of time-lapse cameras to collect boating activities at boat ramps provides a useful alternative to collect effort data that can improve the accuracy and precision of estimates (Hartill et al., 2019, 2016; Keller et al., 2016; Stahr and Knudsen, 2018; Taylor et al., 2018). Estimates from independent survey methods may be compared to understand potential bias in estimates derived from survey data, which need to be reliable if they are to inform resource assessment and fishery management. Inferences drawn from survey data for use in management decisions also need to be accepted by managers and stakeholders. In other words, evaluating survey methods may provide information that can increase confidence in the use of catch estimates in management decision making for recreational fisheries (Hartill and Edwards, 2015).
However, it is often not financially feasible to conduct off-site and on-site surveys concurrently for validation. There are only a few corroboration studies for recreational fisheries (Table 1). These studies are mostly for single species or single habitat recreational fisheries, although the New Zealand study presented estimates for several major and secondary species (Hartill and Edwards, 2015; Holdsworth et al., 2018). For a multi-species recreational fishery, more reliable information is required for a suite of species or from multiple habitats to understand the dynamics of the fishery.
The boat-based recreational fishery in the West Coast Bioregion of Western Australia harvests more than 100 species, mainly demersal and nearshore species, using line fishing methods. Recreational (and commercial) harvest of the demersal resource includes several species that are long-lived and susceptible to overfishing. A stock assessment conducted in 2007 indicated some of the major demersal species were overfished (Wise et al., 2007). Hence, management arrangements were implemented progressively between 2007–2010 aiming to recover the resource. This recovery was monitored by on-site Bus-route Access Point (BAP) surveys in the West Coast Bioregion until 2010 (Lai et al., 2019). The introduction of a Recreational Boat Fishing Licence (RBFL) in 2010 provided a sampling frame for off-site statewide Phone-Diary (PD) surveys which have been conducted biennially since 2011 (Ryan et al., 2019). The first statewide PD survey was conducted in 2011/12, with on-site BAP and Remote Camera (RC) surveys conducted concurrently at a smaller scale. This provided an opportunity to assess the comparability of estimates provided by different survey approaches.
The aim of this paper is to provide statistical comparisons of estimated effort (fishing trips, trip time and fishing time) and catch (retained and released) for key demersal and nearshore species of a boat-based recreational fishery in Western Australia from off-site and on-site surveys. This study evaluates the reliability of survey data collected from off-site PD, on-site BAP and RC surveys collected over a 12-month period. Corroboration of estimates is relevant for recreational fisheries that rely on probability-based surveys to inform management decision making, and where confidence in survey results among managers and stakeholders is important.
Section snippets
Study area
The Perth metropolitan (Metro) area of Western Australia has approximately 73 % of the statewide population and the majority of RBFL holders reside there. The adjacent coastline extends 125 km (representing 1% of the statewide coastline of 12,889 km), with 24 public boat ramps, from Lancelin (latitude 31 °S) to south of Mandurah (latitude 33 °S). Most boat-based recreational fishing in Western Australia occurs in the coastal waters off the Metro area. The recreational fishery is a multispecies
Comparison of unweighted survey data
The distributions of trip time and fishing time from the PD and BAP surveys were significantly different as indicated by the Kolmogorov-Smirnov (K–S) test, even though a t-test did not indicate significant differences in the means (Fig. 2, Table S4). On the other hand, the K–S test and t-test indicated that the distributions and the means of non-zero catch (number retained and released) for most of the key species were similar, except the retained catch distributions for Australian herring, the
Discussion
Comparisons of survey data and estimates from different survey methods, where available, can improve understanding of the limitations of survey designs and assist in the development of robust and cost-effective survey designs for monitoring recreational fisheries (Bellanger and Levrel, 2017; Zarauz et al., 2015). In this study, comparisons of effort and catches derived from off-site and on-site surveys have identified biases in survey data, which influences subsequent estimation.
Conclusion
Off-site surveys are cost-effective and robust methods for long-term monitoring of recreational fishing at national or statewide levels. It is important to enhance the scientific credibility of the results provided by the surveys and improve stakeholder acceptance of the results. This can be achieved by means of on-site validation studies, in which independent on-site surveys provide estimates as reference points to compare estimates from off-site surveys. When there are no estimates of
CRediT authorship contribution statement
Eva K.M. Lai: Conceptualization, Methodology, Software, Validation, Formal analysis, Writing - original draft. Karina L. Ryan: Conceptualization, Methodology, Supervision, Writing - review & editing. Ute Mueller: Supervision, Writing - review & editing. Glenn A. Hyndes: Supervision, Writing - review & editing.
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgements
The authors would like to thank Professor Ken Pollock, Norm Hall, Rod Lenanton and Brent Wise for advice with designing the PD and BAP surveys, and staff from the Department of Primary Industries and Regional Development for planning and implementation of the surveys and maintenance of the remote camera network. We are appreciative of the many recreational fishers who voluntarily participated in the surveys. We thank David Fairclough and Shane Walters for reviewing an earlier version of the
References (50)
- et al.
A cost-effectiveness analysis of alternative survey methods used for the monitoring of marine recreational fishing in France
Ocean Coast. Manag.
(2017) - et al.
Estimating harvest and its uncertainty in heterogeneous recreational fisheries
Fish. Res.
(2017) - et al.
Bridging the temporal gap: continuous and cost-effective monitoring of dynamic recreational fisheries by web cameras and creel surveys
Fish. Res.
(2016) - et al.
Integrated survey methods to estimate harvest by marine recreational fishers in New Zealand
Fish. Res.
(2018) - et al.
Monitoring boat-based recreational fishing effort at a nearshore artificial reef with a shore-based camera
Fish. Res.
(2016) - et al.
Comparing estimates of catch and effort for boat-based recreational fishing from aperiodic access-point surveys
Fish. Res.
(2019) - et al.
Pilot surveys to improve monitoring of marine recreational fisheries in Hawaiʻi
Fish. Res.
(2018) - et al.
Research and management priorities for Atlantic marine recreational fisheries in Southern Europe
Mar. Policy
(2017) - et al.
Economic, social and ecological attributes of marine recreational fisheries in Galicia, Spain
Fish. Res.
(2018) - et al.
Investigating bias in recreational fishing surveys: fishers listed in public telephone directories fish similarly to their unlisted counterparts
Fish. Res.
(2016)