Functional and Numerical Responses: A Framework for Fish‐Angler Interactions?

Abstract

A conceptual framework for sport fisheries in which fish—angler interactions are viewed as a dynamic predator—prey relationship was evaluated with data from the walleye fishery in Lake Mendota, Wisconsin. A detailed 7—yr creel survey data set for this fishery revealed a link between fish and angler dynamics. Angler catch rates were positively and linearly related to fish abundance over the range of data in the study. Angling effort was positively related to catch rate. Fish—angler relationships were obscured by three difficulties commonly associated with fishery data sets: seasonal responses, measurement errors in predictor variables, and time series bias. Statistical techniques removed each of these biases, but the data were still insufficient to conclusively identify an appropriate model for the interaction. Nevertheless, it is clear that assumptions of static angler response to sport fish manipulations are unwarranted and capable of seriously confounding management efforts. Interactions among anglers and the influence of alternative fisheries outside the observed system appeared to be important. A combination of longer duration studies on a broader geographic scale and manipulative management experiments is probably necessary to advance our understanding of fish—angler interactions.

Functional response of fishers in the Isle of Man scallop fishery

“…Beukers-Stewart et al 2003, Maunder & Punt 2004) but can also be considered as rate of prey consumption (e.g. Johnson & Carpenter 1994). Simply using mean fleet CPUE does not provide a good index of abundance, as CPUE may become equalised over fished areas as fishers move to maintain catches (Gillis et al 1993, Gillis 2003.…”

“…The functional response describes the same relationship in ecology as that between prey abundance and catch rates in fisheries science (Johnson & Carpenter 1994, Eggleston et al 2008. Relationships between predator and prey populations have been widely described in terms of numerical and functional responses (e.g.…”

“…These include studies of both artisanal (Beckerman 1983, Begossi 1992, Béné & Tewfik 2001 and mechanised (Gillis et al 1993, Rijnsdorp et al 2000a,b, Gillis 2003 fisheries. Johnson & Carpenter (1994) examined fish and angler interactions within a framework of numerical and functional responses. Furthermore, Eggleston et al (2008) identified the aggregate functional response of fishers in a Caribbean spiny lobster Panulirus argus fishery and the implications for management.…”

“…Such an approach would be valuable in identifying appropriate management strategies in other fisheries. The lack of spatiotemporal information of sufficient resolution could prevent such an approach being applied, and a number of the difficulties encountered, such as seasonality, are highlighted by Johnson & Carpenter (1994). However, with the advent of satellite monitoring of individual vessels, examining the functional response of fishers will become much more widely applicable in the future, and several studies have examined fishing effort using satellite monitoring data (Mills et al 2007, Lee et al 2010, Gerritsen & Lordan 2011.…”

Los seres humanos como depredadores: una visión general de las estrategias de depredación seguidas por cazadores con distintas motivaciones

“…We evaluated whether an article contained an evaluation of the functional response of hunters to altering prey abundances by first reading the title, then the abstract, and finally if we regarded articles were relevant we read the fulllength article. We have included fisheries studies here as well, partly because the sample size would have been exceptionally low if we had only used harvest of terrestrial animals, and partly because there are no apriori reasons to expect that fishermen should behave different from hunters in terrestrial systems (Johnson and Carpenter, 1994). In total, 101 articles matched our search criteria, but only 8 provided explicit evaluations of predation strategies among hunters or fishermen.…”