Angler Behavior in Response to Management Actions on Nebraska Reservoirs - Part II
GoalsProject goals are to understand 1) the participation patterns of anglers on multiple spatial and temporal scales; 2) how participation patterns of anglers’ influence fish populations and associated communities; 3) how management actions influence angler participation patterns and, in turn, fish communities; and 4) interactions and feedback mechanisms between and among angler groups and fish communities.
The project currently has eight study components.
1. Statewide Angler Survey. Anglers are being interviewed at Branched Oak Lake, Calamus Reservoir, Gracie Creek Pond, Harlan County Reservoir, Lake McConaughy, Merritt Reservoir, Pawnee Reservoir, Sherman Reservoir, and Lake Wanahoo from April through October, 2014–2018. These interviews add to long–term (>10–20 years) data sets that are valuable for assessment of temporal changes in angler participation. In particular, these extended data sets will allow for relational assessments of changes in angling participation with environmental conditions and management actions on large–scales.
2. Recreational use of Valentine National Wildlife Refuge. Understanding participation patterns is critical for effective resource management. A combination of cameras and surveys will be used to understand 1) how much time visitors spend on the refuge and 2) what types of recreational activities occur on the refuge. Spatial and temporal recreational information will aid in optimizing resources at this multi-use refuge.
3. Individual-Based Model Describes Behavioral Feedbacks between Anglers and Sportfish. Behavioral feedbacks between anglers and sportfish are widely recognized to be important in the management of sustainable and economically viable recreational fisheries. Quantifying these feedbacks empirically is difficult. Individual-based modeling has proven to be a powerful tool for assessing ecological processes. We used this computational-modeling form to simulate various assumptions associated with fishery-induced behavioral changes within an exploited fish population. These simulations result in robust-emergent relationships, over many model iterations, between empirically represented anglers and hypothetical sportfish. This provides a theoretical framework for in situ assessments of behavioral feedbacks between anglers and sportfish. Modeling efforts for this project are complete and we are currently working towards publication.
4. Using Naïve Systems to Identify How Angling Influences Fish Populations. Catchability of sportfish can be negatively affected by repeated capture with catch-and-release angling, which is potentially a result of learned hook avoidance. The opening of two new reservoirs in eastern Nebraska to angling provided a unique opportunity to assess this relationship. Lake Wanahoo and Prairie Queen Lake were stocked and allowed to develop without angling for several years prior to opening. Thus, we assumed that fish were naïve to angling. We hypothesized that learned hook avoidance would be more prevalent in release-oriented than harvest-oriented fish populations, resulting in a more rapid decline of angler catch per unit effort (CPUE) for release-oriented species. At Wanahoo, we observed a marked decrease in the CPUE of release-oriented species, but we did not observe declines in CPUE for harvest-oriented fish. This suggests that individuals may develop learned behavior to avoid recapture and has strong implications for efficacy of management regulations and angler satisfaction. However, we did not achieve the same results at Prairie Queen, highlighting the complexities of the system and the need for continued research. Currently, we are in the process of submitting a note for publication regarding the observations at Lake Wanahoo and Prairie Queen Lake.
5. Quantifying the Effect of Fish Personality on Fishing-induced Learning. Fish populations display reduced catchability over time in catch-and-release fisheries, suggesting that individual fish have the ability to learn to avoid capture. We investigated the effect of a fish’s personality on its ability to learn. Behavioral tests and repeated fishing trials were conducted in a laboratory to determine where an individual falls along a boldness continuum, and if certain fish personality types are better able to learn to avoid a lure. Fish offered a worm on a hook-less wire increased their probability of taking the worm over the seven-day fishing trials. Fish offered a worm on a simple hook displayed a decreasing probability of capture over time, and fish offered a worm on a lure started out at a lower probability of capture and also showed evidence of decreasing probability of capture over time. Learning ability did not differ between bold and shy phenotypes; however, bold individuals did demonstrate a greater initial probability of capture across treatments. Therefore, anglers may disproportionately affect bold individuals through angling activities. We are currently preparing a manuscript for publication regarding probability of capture and personality type. Additional analysis of information collected during behavioral and fishing experiments is still underway.
6. Spatial Distribution of Angler Parties. Anglers must decide where to fish within a waterbody, yet most assessments of fisheries via angler surveys provide only whole–waterbody estimates of angler pressure. Angler distribution within a waterbody is not uniform, and if anglers are not randomly distributed, then anglers are selecting for factors within a waterbody. Behavior for anglers fishing from the shoreline was recorded for entire, individual, fishing trips, and behavior was compared to angler-perceived fishing objectives. Angler objectives had little influence on behavior, and behavior had little influence on outcome. However, anglers that failed to capture a fish were more likely to shift to a non-catch-related objective during their fishing trip. Further, ease-of-access had the greatest effect on angler densities. By measuring within-trip angler behavior and site choice, we may be able to more effectively manage recreational fisheries at greater scales.
7. Anglershed dynamics in recreational fisheries. An angler’s mobile nature coupled with the seasonality of a year creates fluctuations in participation at a waterbody. Despite this, there is little understood about angler behavior, especially spatiotemporal participation dynamics on patch and ecosystem scales. We will complete an investigation of creel survey data specifically regarding spatial and temporal dynamics of angler participation (i.e., anglersheds). This initial investigation will highlight potential patterns in participation dynamics that can be linked to geographical, social, and demographic attributes of the users and the resource. Information gained by this research will provide managers with a greater understanding of participation across a fishing season within and between waterbodies, as well as an understanding of where anglers are coming from to visit a waterbody.
8. Length-based Economic Assessment of Sportfish. Recreational fisheries are a unique industrial component to Nebraska’s economy. Anglers derive value in a variety of forms by taking part in recreational fisheries. Quantifying this value requires assessing individual anglers’ willingness-to-pay to capture a fish and for each successive capture. Anglers also express unique preferences and motivations. Thus, we expect angler’s willingness-to-pay to vary widely for different angling-trip outcomes (i.e., species and size). We are using a length-based valuation framework that generalizes the preferences and motivations of Nebraska anglers across a variety of sociological metrics. This assessment will provide a length-specific value of captured sportfish stratified across Nebraska’s angling groups. Online valuation surveys are ongoing with over 1000 individual responses to date. Preliminary analysis and modeling is underway to assess general relationships between length-based values of fish and angling-trip outcomes.
Project WebsiteFish Hunt
Principal Investigator(s)-Kevin Pope, NE CFWRU
-Christopher J. Chizinski, University of Nebraska-Lincoln