Geology topics

Christopher J. Chizinski

Publications and source records attributed to Christopher J. Chizinski.

At least 19 recordsLinked to original sources

USGS2022

Valuing angling on reservoirs using benefit transfer

Economic assessments are rarely applied to inland recreational fisheries for management purposes, especially when compared to fish, habitat, and creel assessments, yet economic assessments can provide critical information for management decisions. We provide a brief overview of economic value, key terminology, and existing economic techniques to address these issues. Benefit transfer, a technique used to measure economic value when an original analysis is not practicable, is conducted by drawing on existing estimates of economic value in similar contexts. We describe an application of benefit transfer to measure the economic value of several recreational fisheries in Nebraska, USA. We examine two approaches to benefit transfer—value transfer and function transfer—which we demonstrate estimate similar economic values for fishing site access but substantially different economic values for catch rate improvements at some reservoirs. We encourage agencies that are responsible for inland recreational fisheries management to consider economic assessment, especially benefit transfer, as a critical tool in the management toolbox.

North American Journal of Fisheries Management↗

USGS2022

Natural resource system size can be used for managing recreational use

Outdoor recreation provides societal benefits that are often measured by the amount of use natural resource systems receive. Still, the amount of resource use natural resource systems receive is often unknown or unstudied. Monitoring and quantifying resource use is often logistically difficult and costly but is paramount to optimize societal benefits. Identifying a simple and readily available metric that can indicate the quantity of recreational use of natural resource systems would benefit natural resource management. Using recreational angler participation data during an 11-year study period from 73 public waterbodies in Nebraska, USA, we developed a resource size-use model that demonstrates the ability of natural resource system size to indicate the quantity of recreational use they receive. We demonstrate how resource size-use models can estimate use for unsampled systems, produce broad-scale estimations of use, guide the allocation of resources, and predict how changes in resource system size may affect use. Resource size-use models provide opportunities to manage recreational use, which has been previously elusive for social-ecological systems.

Nebraska↗

USGS2021

Temporal invariance of social-ecological catchments

Natural resources such as waterbodies, public parks, and wildlife refuges attract people from varying distances on the landscape, creating "social-ecological catchments." Catchments have provided great utility for understanding physical and social relationships within specific disciplines. Yet, catchments are rarely used across disciplines, such as its application to understand complex spatiotemporal dynamics between mobile human users and patchily distributed natural resources. We collected residence ZIP codes from 19,983 angler parties during 2014–2017 to construct seven angler–waterbody catchments in Nebraska, USA. We predicted that sizes of dense (10% utilization distribution) and dispersed (95% utilization distribution) angler–waterbody catchments would change across seasons and years as a function of diverse resource selection among mobile anglers. Contrary to expectations, we revealed that catchment size was invariant. We discuss how social (conservation actions) and ecological (low water quality, reduction in species diversity) conditions are expected to impact landscape patterns in resource use. We highlight how this simple concept and user-friendly technique can inform timely landscape-level conservation decisions within coupled social-ecological systems that are currently difficult to study and understand.

Ecological Applications↗

USGS2020

An open-sourced, web-based application to improve our ability to understand hunter and angler purchasing behavior from license data

State fish and wildlife agencies rely on hunters and anglers (i.e., sportspersons) to fund management actions through revenue generated from license sales and excise taxes on hunting and fishing equipment. There is a need to develop new techniques that bridge the information gap on participation and provide agencies with an understanding of sportspersons at a resolution that can more directly inform efforts to engage sportspersons. Monitoring sportsperson participation using information about their license-purchasing behavior has the potential to reveal important patterns in recruitment (first-time purchase of a hunting or fishing license), retention (continued purchase of licenses across multiple years), and reactivation (purchase a license after several years with no purchases). Providing up-to-date information on what licenses are purchased, when and by whom may prove invaluable to managers and policy makers. We present a customizable, open-source, web-based application—huntfishapp—that allows the user to query and interact with a structured query language (SQL) hunting and fishing license database. The huntfishapp serves as an informational resource and tool that provides a framework to share information on license sales across an agency, with intent of increasing understanding of (a) sportspersons and (b) how management decisions affect sportspersons. Data dashboards, like the huntfishapp, allow agencies and non-governmental organizations to become more knowledgeable of their customer base and provide a greater understanding of management-decision effects on hunting and fishing participation.

PLoS ONE↗

USGS2020

Spatial and temporal behavioral differences between angler-access types

Recreational angler surveys typically collect information on how anglers access a fishery. Yet, it is unclear how this information is useful for fisheries management and conservation. The objective of this study was to compare behavior (e.g., party size, time fished, and numbers of fish released and harvested) of bank and boat anglers, representing two angler-access types. Bank and boat anglers were surveyed across 29 Nebraska waterbodies from April through October, 2007–2017. We documented behavioral differences between bank and boat anglers that varied as a function of waterbody size and season. Patterns of party size, time fished, and numbers of fish released and harvested for bank and boat anglers differed across extra small, small, medium, and large waterbodies and across spring, summer, and fall. How anglers choose to access a fishery appears to be a source of heterogeneity within angler populations. Accounting for these spatial and temporal behavioral differences between angler-access types will be important for designing and implementing management regulations. We predict that angler-access types may respond uniquely to different management actions (e.g., size and bag limits, access maintenance, and cleanliness of amenities) that could lead to local and regional changes within and across fisheries (e.g., shift the composition of angler-access types). Continued collection and assessment of angler-access information is warranted and should lead to improved management and conservation of recreational fisheries.

Nebraska↗

USGS2020

Harvest–release decisions in recreational fisheries

Most fishery regulations aim to control angler harvest. Yet, we lack a basic understanding of what actually determines the angler’s decision to harvest or release fish caught. We used XGBoost, a machine learning algorithm, to develop a predictive angler harvest–release model by taking advantage of an extensive recreational fishery data set (24 water bodies, 9 years, and 193 523 fish). We were able to successfully predict the harvest–release outcome for 99% of fish caught in the training data set and 96% of fish caught in the test data set. Unsuccessful predictions were mostly attributed to predicting harvest of fish that were released. Fish length was the most essential feature examined for predicting angler harvest. Other important predictive harvest–release features included the number of individuals of the same species caught, geographic location of an angler’s residence, distance traveled, and time spent fishing. The XGBoost algorithm was able to effectively predict the harvest–release decision and revealed hidden and intricate relationships that are often unaccounted for with classical analysis techniques. Exposing and accounting for these angler–fish intricacies is critical for fisheries conservation and management.

Nebraska↗

USGS2019

Public access for pheasant hunters: Understanding an emerging need

Ring-necked pheasant ( Phasianus colchicus ; i.e., pheasant) hunting participation is declining across North America, reflecting a larger downward trend in American hunting participation and threatening benefits to grassland conservation and rural economies. To stabilize and expand the pheasant hunting population, we must first identify factors that influence pheasant hunter participation. We used an extensive in-person hunter survey to test the hypothesis that hunter demographics interact with social-ecological traits of hunting locations to affect hunter decisions, outcomes, and perceptions. We built a series of Bayesian mixed effects models to parse variation in demographics, perceptions, and hunt outcomes of pheasant hunters interviewed at public access hunting sites across 3 regions in Nebraska, USA, that varied in pheasant abundance and proximity to urban population centers. Among pheasant hunters in Nebraska, access to private lands was negatively related to the human population density of a pheasant hunter's home ZIP code and the distance a hunter had traveled to reach a hunting location. Pheasant hunters interviewed closer to metropolitan areas tended to be more urban and travel shorter distances, and their parties were more likely to include youth but less likely to include dogs. Hunter satisfaction was positively associated with seeing and harvesting pheasants and hunting with youth. Whereas youth participation and the number of pheasants seen varied by study region, hunter satisfaction did not differ across regions, suggesting that hunters may calibrate their expectations and build their parties based on where they plan to hunt. The variation in hunter demographics across hunting locations and disconnects between social and ecological correlates of hunter satisfaction suggests that diverse pheasant hunting constituencies will be best served by diverse pheasant hunting opportunities.

Nebraska↗

USGS2018

Variation in angler distribution and catch rates of stocked rainbow trout in a small reservoir

We investigated the spatial and temporal relationship of catch rates and angler party location for two days following a publicly announced put-and-take stocking of rainbow trout ( Oncorhynchus mykiss ). Catch rates declined with time since stocking and distance from stocking. We hypothesized that opportunity for high catch rates would cause anglers to fish near the stocking location and disperse with time, however distance between angler parties and stocking was highly variable at any given time. Spatially explicit differences in catch rates can affect fishing quality. Further research could investigate the variation between angler distribution and fish distribution within a waterbody.

PLoS ONE↗

USGS2018

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

Networks used to study interactions could provide insights to fisheries. We compiled data from 27 297 interviews of anglers across waterbodies that ranged in size from 1 to 12 113 ha. Catch rates of fish species among anglers grouped by species targeted generally differed between angling methods (bank or boat). We constructed angler–catch bipartite networks (angling method specific) between anglers and fish and measured several network metrics. There was considerable variation in networks among waterbodies, with multiple metrics influenced by waterbody size. Number of species-targeting angler groups and number of fish species caught increased with increasing waterbody size. Mean number of links for species-targeting angler groups and fish species caught also increased with waterbody size. Connectance (realized proportion of possible links) of angler–catch interaction networks decreased slower for boat anglers than for bank anglers with increasing waterbody size. Network specialization (deviation of number of interactions from expected) was not significantly related to waterbody size or angling methods. Application of bipartite networks in fishery science requires careful interpretation of outputs, especially considering the numerous confounding factors prevalent in recreational fisheries.

Canadian Journal of Fisheries and Aquatic Sciences↗

USGS2017

Estimating the number of recreational anglers for a given waterbody

Knowing how many anglers use a given body of water is paramount for understanding components of a fishery related to angling pressure and harvest, yet no study has attempted to provide an estimate of the population size of anglers for a given waterbody. Here, we use information from creel surveys in a removal-sampling framework to estimate total numbers of anglers using six reservoirs in Nebraska, USA, and we examine the influence of the duration of sampling period on those estimates. Population estimates (N ± SE) of unique anglers were 2050 ± 45 for Branched Oak Lake, 1992 ± 29 for Calamus Reservoir, 929 ± 10 for Harlan County Reservoir, 985 ± 24 for Lake McConaughy, 1277 ± 24 for Merritt Reservoir, and 916 ± 18 for Pawnee Lake during April–October 2015. Shortening the sampling period by one or more months generally resulted in a greater effect on estimates of precision than on estimates of overall abundance. No relationship existed between abundances of unique anglers and angling pressures across reservoirs and sampling duration, indicative of a decoupling of angler abundance and angling pressure. The approach outlined herein has potential to provide defendable answers to “how many are there?”, questions we ask when subjects cannot be marked, which should provide new insights about angler populations and subpopulations.

Nebraska↗

USGS2017

Network analysis of a regional fishery: Implications for management of natural resources, and recruitment and retention of anglers

Angler groups and water-body types interact to create a complex social-ecological system. Network analysis could inform detailed mechanistic models on, and provide managers better information about, basic patterns of fishing activity. Differences in behavior and reservoir selection among angler groups in a regional fishery, the Salt Valley fishery in southeastern Nebraska, USA, were assessed using a combination of cluster and network analyses. The four angler groups assessed ranged from less active, unskilled anglers (group One) to highly active, very skilled anglers (group Four). Reservoir use patterns and the resulting network communities of these four angler groups differed; the number of reservoir communities for these groups ranged from two to three and appeared to be driven by reservoir location (group One), reservoir size and its associated attributes (groups Two and Four), or an interaction between reservoir size and location (group Three). Network analysis is a useful tool to describe differences in participation among angler groups within a regional fishery, and provides new insights about possible recruitment of anglers. For example, group One anglers fished reservoirs closer to home and had a greater probability of dropping out if local reservoir access were restricted.

Fisheries Research↗

USGS2015

Accuracy or precision: Implications of sample design and methodology on abundance estimation

Sampling by spatially replicated counts (point-count) is an increasingly popular method of estimating population size of organisms. Challenges exist when sampling by point-count method, and it is often impractical to sample entire area of interest and impossible to detect every individual present. Ecologists encounter logistical limitations that force them to sample either few large-sample units or many small sample-units, introducing biases to sample counts. We generated a computer environment and simulated sampling scenarios to test the role of number of samples, sample unit area, number of organisms, and distribution of organisms in the estimation of population sizes using N -mixture models. Many sample units of small area provided estimates that were consistently closer to true abundance than sample scenarios with few sample units of large area. However, sample scenarios with few sample units of large area provided more precise abundance estimates than abundance estimates derived from sample scenarios with many sample units of small area. It is important to consider accuracy and precision of abundance estimates during the sample design process with study goals and objectives fully recognized, although and with consequence, consideration of accuracy and precision of abundance estimates is often an afterthought that occurs during the data analysis process.

Ecological Modelling↗

USGS2015

Masked expression of life-history traits in a highly variable environment

Differing life-history strategies may act as a constraint on reproductive expression that ultimately limits the ability of individual species to respond to changes in the magnitude or frequency of environmental variation, and potentially underlies the variation often inherent in phenotypic and evolved responses to anthropogenic change. Alternatively, if there are environmental cues that predict reproductive potential, differential expression of life-history strategies may represent differences in the adaptive capacity to optimize current reproductive value given variation in environmental conditions. We compared several aspects of walleye Sander vitreus spawning ecology at two reservoirs that differ in environmental variability (i.e., annual water-level fluctuation) to identify the capacity of phenotypic expression and the corresponding association with age. Despite significant differences in female body and liver masses between reservoirs that differ in environmental variability, we found no difference in reproductive investment measured by egg size and fecundity. Walleye in a highly variable environment appear to exhibit reproductive traits more typical of a short-lived life-history strategy, which may be resultant from the interaction of environmental and anthropogenic pressures. This finding emphasizes the need to identify the degree to which life-history expression represents physiological constraints versus ecological optimization, particularly as anthropogenic change continues to alter environmental conditions.

Great Plains Research↗

USGS2014

Angler effort and catch within a spatially complex system of small lakes.

Spatial layout of waterbodies and waterbody size can affect a creel clerk’s ability to intercept anglers for interviews and to accurately count anglers, which will affect the accuracy and precision of estimates of effort and catch. This study aimed to quantify angling effort and catch across a spatially complex system of 19 small (<100 ha) lakes, the Fremont lakes. Total (±SE) angling effort (hours) on individual lakes ranged from 0 (0) to 7,137 (305). Bank anglers utilized 18 of the 19 lakes, and their mean (±SE) trip lengths (hours) ranged from 0.80 (0.31) to 7.75 (6.75), depending on the waterbody. In contrast, boat anglers utilized 14 of the 19 lakes, and their trip lengths ranged from 1.39 (0.24) to 4.25 (0.71), depending on the waterbody. The most sought fishes, as indexed by number of lakes on which effort was exerted, were anything (17 of 19 lakes), largemouth bass Micropterus salmoides (15 of 19 lakes), and channel catfish Ictalurus punctatus (13 of 19 lakes). Bluegill Lepomis machrochirus , crappie Pomoxis spp., and largemouth bass were caught most frequently across the lakes, but catch rates varied considerably by lake. Of the 1,138 parties interviewed, most parties (93%) visited a single lake but there were 77 (7%) parties that indicated that they had visited multiple lakes during a single day. The contingent of parties that visited more than one lake a day were primarily (87%) bank anglers.. The number of lake-to-lake connections made by anglers visiting more than one waterbody during a single day was related to catch rates and total angling effort. The greater resolution that was achieved with a lake specific creel survey at Fremont lakes revealed a system of lakes with a large degree of spatial variation in angler effort and catch that would be missed by a coarser, system-wide survey that did not differentiate individual lakes.

Fisheries Research↗

USGS2014

Self-imposed length limits in recreational fisheries

A 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 self-imposed 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.

Nebraska↗

USGS2014

Using posts to an online social network to assess fishing effort

Fisheries management has evolved from reservoir to watershed management, creating a need to simultaneously gather information within and across interacting reservoirs. However, costs to gather information on the fishing effort on multiple reservoirs using traditional creel methodology are often prohibitive. Angler posts about reservoirs online provide a unique medium to test hypotheses on the distribution of fishing pressure. We show that the activity on an online fishing social network is related to fishing effort and can be used to facilitate management goals. We searched the Nebraska Fish and Game Association Fishing Forum for all references from April 2009 to December 2010 to 19 reservoirs that comprise the Salt Valley regional fishery in southeastern Nebraska. The number of posts was positively related to monthly fishing effort on a regional scale, with individual reservoirs having the most annual posts also having the most annual fishing effort. Furthermore, this relationship held temporally. Online fishing social networks provide the potential to assess effort on larger spatial scales than currently feasible.

Nebraska↗

USGS2013

Effects of simulated angler capture and live-release tournaments on walleye survival

We examined the effects of acclimation water temperature,live‐well (LW) water temperature,and LW dissolved oxygen (DO) concentration on survival of adult Walleyes Sander vitreus subjected to simulated tournament conditions (angling,LW confinement,and weigh‐in procedures) under controlled laboratory conditions. We tested three acclimation temperatures (12,18,and 24°C),and three LW temperature differentials (Δ T = −4,0,and +4°C) were tested at each acclimation temperature. Survival was monitored after 8 h of LW confinement and during a 5‐d retention period in 1,700‐L tanks. None of the Walleyes that were acclimated to 24°C and subjected to simulated tournament procedures survived the 5‐d retention period; for fish subjected only to simulated angling at 24°C,survival during the 5‐d retention period was 29%. Five‐day survival was generally over 70% at acclimation temperatures of 12°C and 18°C,and we observed a significant interaction between acclimation temperature and Δ T ; survival was greatest in LWs at −4°C Δ T for fish acclimated to 18°C and in LWs at +4°C Δ T for fish acclimated to 12°C. Best survival of Walleyes subjected to the stress of angling and tournament procedures was obtained at temperatures 6–8°C below the optimum temperature for adult Walleyes (i.e.,optimum = 20–22°C). Five‐day survival exceeded 70% when LW DO was 5 or 12–15 mg/L (at an acclimation and LW temperature of 18°C),but survival was 0% when DO was 2 mg/L. Anglers may increase survival of Walleyes through careful manipulation of LW temperature and DO when ambient temperature is at or below 18°C,but high mortality of angled and LW‐retained Walleyes should be expected when ambient water temperatures are 24°C or greater.

Minnesota↗

USGS2011

Implications of community concordance for assessing stream integrity at three nested spatial scales in Minnesota, U.S.A.

1. Fish and invertebrate assemblage data collected from 670 stream sites in Minnesota (U.S.A.) were used to calculate concordance across three nested spatial scales (statewide, ecoregion and catchment). Predictive taxa richness models, calibrated using the same data, were used to evaluate whether concordant communities exhibited similar trends in human‐induced taxa loss across all three scales. Finally, we evaluated the strength of the relationship between selected environmental variables and the composition of both assemblages at all three spatial scales. 2. Significant concordance between fish and invertebrate communities occurred at the statewide scale as well as in six of seven ecoregions and 17 of the 21 major catchments. However, concordance was not consistently indicative of significant relationships between rates of fish and invertebrate taxa loss at those same scales. 3. Fish and invertebrate communities were largely associated with different environmental variables, although the composition of both communities was strongly correlated with stream size across all three scales. 4. Predictive taxa‐loss models for fish assemblages were less sensitive and precise than models for invertebrate assemblages, likely because of the relatively low number of common fish taxa in our data set. Both models, however, distinguished reference from non‐reference sites. 5. The importance of concordance, geographic context and scale are discussed in relation to the design and interpretation of stream integrity indicators. In particular, our findings suggest that community concordance should not be viewed as a substitute for an evaluation of how assemblages respond to environmental stressors.

Minnesota↗