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

Intraspecific resource partitioning by an opportunistic strategist, inland silverside \u3ci\u3eMenidia beryllina\u3c/i\u3e

Seasonal variation in prey consumption and food resource overlap was evident in an inland water body for mature male, mature female and immature inland silverside (Menidia beryllina). During the first growth phase marked by intensive somatic growth by immature inland silverside, few adults were present in the population (28% of total catch), thus minimizing intraspecific competition for food resources between juvenile and adult inland silverside. During the second growth phase by adults, few juvenile inland silverside were present (0% of total catch) in the population, again minimizing intraspecific competition for food resources between juvenile and adult inland silverside. A divergence in food resource overlap was observed when mature male, mature female and immature inland silverside were present in the population. These population-level demographic responses to energy acquisition are likely necessary to maximize individual growth of mature male, mature female and immature inland silverside resources unless there is differentiation in food resources. For the purpose of this study, the focus was on intraspecific partitioning of food resources by inland silverside because M. beryllina is the main obligate planktivore in the inland water body studied. Other studies have focused on interspecific competition of inland silverside with its congener Atlantic silverside (Menidia menidia) (Bengtson, 1982, 1984, 1985). In order to meet the energy demand of the two coinciding growth periods (first stage juvenile growth and second stage adult growth), partitioning of food resources is expected so that suitable energy is available to meet demands of the mature male, mature female, and immature inland silverside. The objective of this study was to characterize the food habits and measure the degree of food-resource overlap between mature male, mature female, and immature inland silverside throughout the breeding and growing seasons in an inland water body

Across-ecoregion analysis suggests a hierarchy of ecological filters that regulate recruitment of a globally invasive fish

Aim Even successful invaders are abundant only in a fraction of locales they inhabit. One of the main challenges in invasion ecology is explaining processes that drive these patterns. We investigated recruitment of a globally invasive fish, common carp (Cyprinus carpio), across three ecoregions to determine the role of environmental characteristics, predatory communities and propagule pressure on the invasion process at coarse and fine spatial scales. Location Lakes across Northern Forest, Temperate Forest and Great Plains ecoregions of North America. Methods We used data from 567 lakes to model presence or absence of carp recruitment using environmental conditions (lake clarity, area, maximum depth), native predatory fishes (micropredators, mesopredators, large predators) and propagule pressure (abundance of adult carp). We formed a set of alternative models and evaluated their support using an information theoretic approach. Once most supported models were identified, we used classification tree to determine how variables included in these models interacted to affect carp recruitment. Finally, we conducted a field experiment to test the predictions of the classification tree analysis. Results Carp recruitment was strongly regulated by processes associated with water clarity, which appeared to function as a broad-scale ecological filter. Carp were unlikely to recruit in clear, oligotrophic lakes (Secchi depth > 2 m) despite the presence of adults in many such systems. Recruitment was more likely to occur in regions with turbid lakes, but abundant micropredators could inhibit it there. Main conclusions Carp recruitment and invasions across large geographic areas are attributable to a two-layer ecological filter with lake clarity/productivity acting as a coarse-scale filter and micropredators acting as a fine-scale filter. This two-layer filter might explain the complex patterns of carp invasions among and within different ecoregions. Ecological filters may also explain the success of other aquatic invaders that show similarly patchy spatial distribution patterns.This article is published as Bajer, Przemek G., Timothy K. Cross, Joseph D. Lechelt, Christopher J. Chizinski, Michael J. Weber, and Peter W. Sorensen. "Across‐ecoregion analysis suggests a hierarchy of ecological filters that regulate recruitment of a globally invasive fish." Diversity and Distributions 21, no. 5 (2015): 500-510. doi:10.1111/ddi.12315. Posted with permission

Economic Value of Angling at a Reservoir with Low Visitation

A travel cost model was used to estimate the per-day consumer surplus for anglers at a reservoir (Lake Kemp, Texas) with low visitation. The average per-day consumer surplus for anglers was $61–122, depending on the wage rate fraction assigned to the opportunity cost of time. Although this consumer surplus value is small, anglers on the numerous smaller public and private water bodies may, in aggregate, generate a majority of the economic value for freshwater angling. Further, the marginal value per dollar spent managing small water bodies is probably large. Arguably, greater attention should be directed toward managing our nation’s numerous smaller water bodies

The future of wildlife conservation funding: What options do U.S. college students support?

Insufficient funding is a major impediment to conservation efforts around the world. In the United States, a decline in hunting participation threatens sustainability of the “user-pay, public benefit” model that has supported wildlife conservation for nearly 100 years, forcing wildlife management agencies to contemplate alternative funding strategies. We investigated support for potential funding options among diverse college students, a rapidly expanding and politically active voting bloc with a potentially powerful influence on the future of conservation. From 2018 to 2020, we surveyed 17,203 undergraduate students at public universities across 22 states. Students preferred innovative approaches to conservation funding, with 72% supporting funding derived from industry sources (e.g., natural resource extraction companies), 63% supporting state sources (e.g., general sales tax), and 43% supporting conventional user-based sources such as license fees and excise taxes associated with outdoor recreation activities (e.g., hunting). Findings emphasize the need to broaden the base of support for conservation funding and highlight the importance of considering the preferences and perspectives of young adults and other diverse beneficiaries of wildlife conservation