Self-imposed length limits in recreational fisheries

Abstract

a b s t r a c tA primary motivating factor on the decision to harvest a fish among consumptive-orientated anglers is the size of the fish. There is likely a cost-benefit trade-off for harvest of individual fish that is size and species dependent, which should produce a logistic-type response of fish fate (release or harvest) as a function of fish size and species. We define the self-imposed length limit as the length at which a captured fish had a 50% probability of being harvested, which was selected because it marks the length of the fish where the probability of harvest becomes greater than the probability of release. We assessed the influences of fish size, catch per unit effort, size distribution of caught fish, and creel limit on the selfimposed length limits for bluegill Lepomis macrochirus, channel catfish Ictalurus punctatus, black crappie Pomoxis nigromaculatus and white crappie Pomoxis annularis combined, white bass Morone chrysops, and yellow perch Perca flavescens at six lakes in Nebraska, USA. As we predicted, the probability of harvest increased with increasing size for all species harvested, which supported the concept of a size-dependent trade-off in costs and benefits of harvesting individual fish. It was also clear that probability of harvest was not simply defined by fish length, but rather was likely influenced to various degrees by interactions between species, catch rate, size distribution, creel-limit regulation and fish size. A greater understanding of harvest decisions within the context of perceived likelihood that a creel limit will be realized by a given angler party, which is a function of fish availability, harvest regulation and angler skill and orientation, is needed to predict the influence that anglers have on fish communities and to allow managers to sustainable manage exploited fish populations in recreational fisheries.

Harvest–release decisions in recreational fisheries

“…tial component to the harvest-release decision, and the relationship was similar across species. Past assessments have assumed that fish harvest follows a linear or logistic relationship with fish size (Chizinski et al 2014). We revealed that harvest is more likely to follow a polynomial relationship with fish size and that predict-ing the harvest-release outcome for larger fish is difficult.…”

“…this assertion, with fish size contributing most to gain and coverage importance in the harvest-release model. Previous work predicted that a threshold exists (i.e., self-imposed length limit) as to when a fish will be released or harvested (Chizinski et al 2014). Fish below this threshold will likely be released and fish above this threshold will likely be harvested, thus balancing the costs and trade-offs of harvest with respect to fish size (Chizinski et al 2014).…”

“…Given the importance of harvest in recreational fisheries and the long history of regulating harvest, we should be able to predict the harvest-release decision with a high degree of certainty (see Hunt et al 2002). We have traditionally operated on the basic premise that fish harvest depends primarily on fish size (Allendorf and Hard 2009;Chizinski et al 2014), but is the angler's decision process really that simple?…”

Bipartite networks improve understanding of effects of waterbody size and angling method on angler–fish interactions

“…Each subgroup of anglers can vary in their specialization, motivations, choice of species targeted, angling method, and tackle choices, among a multiplicity of other factors. Thus, during any given period at a waterbody there is a heterogeneous suite of anglers fishing for a multitude of species (Chizinski et al 2014a(Chizinski et al , 2014b, using various gears and approaches (e.g., angling from a boat or bank). Furthermore, no angling tackle or bait is exclusive to the species being targeted.…”

Influence of a Minimum‐Length Limit Regulation on Wild Brown Trout: an Example of Recruitment and Growth Overfishing

“…To counteract this, some countries have modified their fishing regulations to promote the release of females (Jonsson and Jonsson 2011). Managers often emphasize the beneficial and deleterious aspects of minimum-length limits or catch-and-release regulations to overcome the overexploitation of fish stocks and fisheries (e.g., Arlinghaus et al 2007;Allen et al 2009;Chizinski et al 2014). However, sustainable fisheries may be achieved by nontraditional harvest regulations such as stabilizing harvest-slot limits (Arlinghaus et al 2010;Gwinn et al 2015) or by restricting fishing of a particular sex (usually to protect females) (Jonsson and Jonsson 2011).…”