38 research outputs found
Environmental Mental Models of College Students
Primary and secondary students in the United States are provided environmental education in their curricula due in part to national legislation, but higher education, for many U.S. citizens, is the last opportunity to educate young adults about the environment and humans’ role in it in a formalized setting. Pre-college education and other life experiences or ways of learning can shape a student’s mental model of the environment. While some previous research has focused on understanding environmental mental models of primary and secondary students, only one study to date has evaluated models of college students. Further, no study has evaluated potential shifts in mental models because of taking a course or what specific factors shape these models prior to college. The objectives of this study were to assess environmental models of college students and determine whether a course on “Environmental Conservation” reinforces or influences students’ mental models by the end of the course. We compared environmental metal models at the start and end of our course using the Environments Task tool. Students were asked to provide pictorial and written descriptions of their mental models at both time periods. Additionally, photographs were used to explore student beliefs on environmental representations and questions were used to assess sources of prior environmental knowledge of students at the start of the semester. Results show that pictorial and written mental models differed from one another at the beginning as well as the end of the semester. More students identified humans as a part of the environment in their pictures by the end of the semester compared to the beginning, but no such shifts were noted in the written description. Students identified secondary school courses, life experiences such as growing up on a farm or ranch or hunting and fishing, and their family members as their primary sources of environmental information prior to taking the course. In total, these results indicate that mental models remain underdeveloped after this specific 16-week course and that these models may be more fixed by earlier educational experiences than previously believed. Recommendations for future environmental education are also provided
Gape:Body Size Relationship for Smallmouth Bass
The types and sizes of prey fishes consumed by predatory fish often are limited by gape dimensions of the predator (Slaughter and Jacobson 2008). In general, the size of prey consumed is positively related to predator size when prey are available across a wide range of sizes (Werner and Hall 1974). Opportunistic predators with large gape dimensions, such as smallmouth bass (Micropterus dolomieu), may consume a wide range of prey types and sizes, thereby exerting top-down influences on prey population dynamics and potentially restructuring aquatic communities (e.g., Werner and Hall 1974, Jackson 2002). Although feeding ecology of smallmouth bass varies with location and prey availability, they typically undergo several ontogenetic diet shifts throughout their development. After yolk sac depletion and as smallmouth bass increase in size from larvae to juveniles (~50 mm total length; TL), targeted prey typically proceeds from microcrustaceans (e.g., copepods) to larger zooplankters (e.g., cladocerans) to macroinvertebrates (e.g., ephemeropterans; Brown et al. 2009). Opportunistic feeding behaviors become more apparent during the juvenile stage (TL \u3e 50 mm) when smallmouth bass begin to consume readily available aquatic macroinvertebrates and prey fishes (Clady 1974, Easton and Orth 1992). Studies evaluating adult feeding ecology highlight the importance of crayfish (Gangl et al. 1997, Liao et al. 2002, Bacula 2009) but also reveal the piscivorous nature of smallmouth bass in some locations (e.g., Jackson 2002, Liao et al. 2002, Bacula 2009, Wuellner et al. 2010)
Channel Catfish Diets Include Substantial Vegetation in a Missouri River Reservoir
Channel catfish (Ictalurus punctatus) are native to Lake Sharpe, a Missouri River mainstem reservoir, and are common in angler catches. Channel catfish growth has declined since the formation of the reservoir in 1963. Mean lengths at time of capture for channel catfish ages 9, 10, II, and 12 have decreased by 69, 55, 115, and 21S mm, respectively, since impoundment. The objective of this study was to document monthly food habits of channel catfish throughout the growing season (May-August) in Lake Sharpe to assess potential effects of diet on growth. Although channel catfish consumed both macro invertebrates and fishes as expected, they also consumed large quantities of submergent aquatic vegetation. Consumed vegetation contributed 3S-73% of the diet by weight over 2 channel catfish length groups «2S0 mm and ~2S0 mm total length) during the 4 months sampled. Consumption of substantial amounts of vegetation should be considered a suboptimal diet for channel catfish growth. Consequently, diets of channel catfish in Lake Sharpe could be a factor contributing to the observed slow growth of older catfish in this population
Depth and Littoral Habitat Association of Age-0 Yellow Perch in Two South Dakota Glacial Lakes
Yellow perch (Perca flavescens) are a recreationally important species and represent a key ecological component of glacial lake littoral fish assemblages (Stone 1996, Blackwell et al. 1999). Research has shown a generalized pattern of juvenile (age-0) yellow perch spatial distribution wherein larvae hatch in near-shore areas, migrate to limnetic areas where they remain for approximately 40 d, and then return to demersal behaviors and within near-shore littoral habitats (Noble 1975, Whiteside et al. 1985). However, anomalous distribution and habitat use by age-0 yellow perch has been observed in South Dakota glacial lakes (Fisher and Willis 1997) and the spatial distribution and habitat association of post-larval (\u3e25 mm) age-0 perch is largely unverified in northern Great Plains glacial lakes. Herein, we report the depth distribution and near-shore (0–2 m depth) habitat association of post-larval, age-0 yellow perch (hereafter referred to as age-0 yellow perch) in two northeastern South Dakota glacial lakes
Consequences of Hatch Phenology on Stages of Fish Recruitment
Little is known about how hatch phenology (e.g., the start, peak, and duration of hatching) could influence subsequent recruitment of freshwater fishes into a population. We used two commonly sympatric fish species that exhibit different hatching phenologies to examine recruitment across multiple life stages. Nine yellow perch (Perca flavescens) and bluegill (Lepomis macrochirus) annual cohorts were sampled from 2004 through 2013 across larval, age-0, age-1, and age-2 life stages in a Nebraska (U.S.A.) Sandhill lake. Yellow perch hatched earlier in the season and displayed a more truncated hatch duration compared to bluegill. The timing of hatch influenced recruitment dynamics for both species but important hatching metrics were not similar between species across life stages. A longer hatch duration resulted in greater larval yellow perch abundance but greater age-1 bluegill abundance. In contrast, bluegill larval and age-0 abundances were greater during years when hatching duration was shorter and commenced earlier, whereas age-0 yellow perch abundance was greater when hatching occurred earlier. As a result of hatch phenology, yellow perch recruitment variability was minimized sooner (age-0 life stage) than bluegill (age-1 life stage). Collectively, hatch phenology influenced recruitment dynamics across multiple life stages but was unique for each species. Understanding the complexities of when progeny enter an environment and how this influences eventual recruitment into a population will be critical in the face of ongoing climate change
Phenology of Annulus Formation in Walleye and Smallmouth Bass Otoliths
Walleye Sander vitreus and smallmouth bass Micropterus dolomieu were sampled monthly (May-October) from Lake Sharpe, South Dakota during 2006 and 2007 to estimate the timing of otolith annulus formation and to evaluate the influence of fish age, sex, and sample location (walleye only) on the timing and detection of annulus formation. Timing of annulus formation was evaluated using marginal increment analysis. Walleye samples were stratified by age, sex, and sample location (i.e., upper and lower Lake Sharpe) and smallmouth bass samples were stratified by age and sex. Monthly mean marginal increment measurements for both species generally increased from May to June, declined in July, and slowly increased from August to October. Although monthly differences in marginal increment measurements across analysis strata were rarely consistent, July generally had the lowest mean marginal increment across species and strata, suggesting that annulus formation in walleye and smallmouth bass in Lake Sharpe likely occurs in July. The lack of differences in timing of annulus formation across species-specific strata was surprising given the well-known influences of age, sex, and water temperature on somatic growth. Nonetheless, results will aid managers in improving the accuracy of age estimates
You Can’t Teach Wildlife and Fisheries Online, Can You? A Comparison of Student Learning and Satisfaction in Two Online and Face-to-Face Courses
Criticisms of online science courses are rooted in the lack to of hands-on learning experiences only available in the face-to-face (f2f) environment. Very few studies have compared student learning outcomes (e.g., assignment, exam, and final grades; level of learning achieved) and student satisfaction between online and f2f courses in the science curriculum, and none of these studies has been done for applied natural resources courses. We are currently conducting a quasi-experiment to compare student learning outcomes and satisfaction for online and f2f versions of two introductory wildlife and fisheries sciences course at South Dakota State University (WL 220: Introduction to Wildlife and Fisheries and WL 230: Wildlife and Fisheries Techniques). To date, we have documented demographic differences between online and face-to-face students in the two courses. Online students tend to be older, have full-time employment, be more experienced in the online environment, and identify themselves more as visual learners than f2f students. Some differences in learning outcomes have been associated with time spent in learning activities within each environment. In the online WL 230 course, the average time spent per week on course tasks was positively associated with overall course grade and individual scores received on assignments related to applying, analyzing, and evaluating information. Time spent outside of class was negatively related to overall course grade in the f2f environment, but class attendance was positively related to course grade and scores on individual assignments that emphasized applying, analyzing, and evaluating information. Insights gleaned from this study may be used to improve and expand online applied natural resources courses. Expansion of these courses may be vital as applied natural resources curricula have been lost nationwide, but these types of knowledge are still very much in demand
A Simple Method to Reduce Interpretation Error of Ages Estimated from Otoliths
We designed and tested a novel otolith viewing apparatus termed the otolith illumination device (OID) to ascertain if its use would result in a reduction of interpretation error as determined by increased precision of age estimates obtained from otoliths of walleye Sander vitreus and smallmouth bass Micropterus dolomieu. Clarity of annuli on otolith sections viewed with the OID was generally greater than clarity of annuli on sections viewed with an alternative method. OID-based age estimates were equally as, and in some instance more precise than ages estimated using the alternative method. Additionally, no systematic differences in coefficients of variation across ages were detected between the OID and alternative methods of fish age estimation. Results suggest that the OID may be useful for inexperienced readers and is a viable option for reducing interpretation error, which may improve reader efficiency and accuracy and precision in estimating fish ages
Student Success Factors in Two Online Introductory-Level Natural Resource Courses
Studies examining potential differences between face-to-face and online courses have been confounded by dissimilarities in student characteristics and their learning strategies used in each environment. In response, research has shifted to determining which intrinsic qualities and learning approaches promote academic success online. The Motivated Strategies for Learning Questionnaire (MSLQ) was used to evaluate the interplay between motivation, expectation, affectation, and learning self-regulation abilities and their potential influences on course performance and effort in two online introductory undergraduate wildlife and fisheries sciences courses. Surprisingly, motivation, expectation, affectation, and self-regulation were often negatively related to course performance but positively related to time spent on the course. Further, motivation, expectancy, and affectation were positively related to self-regulation. Such results appear confounding given that effort and the ability to self-regulate learning are often discussed as important factors to academic success, particularly in the online environment. Perhaps students are not spending time on the appropriate learning strategies for that environment or are over reporting their perceived abilities to self regulate. Overall, this study highlights the complex interplay between intrinsic student factors, learning strategies, and academic success, and further research is needed to better facilitate online learning
Exploring Interactions Between Walleye and Smallmouth Bass in South Dakota Waters
Walleye Sander vitreus are the most popular fish among South Dakota anglers, but smallmouth bass Micropterus dolomieu were introduced to provide new angling opportunities. Some walleye anglers reported subsequent reductions in the quality of walleye fisheries since the introduction of smallmouth bass in South Dakota waters and attribute this decline to consumption of young walleye by smallmouth bass and competition for shared prey resources. I used field- and experimental-based approaches to determine whether smallmouth bass negatively influence walleye in South Dakota. The objectives of this study were to: 1) determine food habits, diet overlap, and the influence of prey and temperature on walleye and smallmouth bass in one Missouri River reservoir; 2) investigate whether population demographics and dynamics are inversely related for the two species across a range of South Dakota water bodies; and 3) evaluate competition and associated feeding behaviors between walleye and bass under various conditions. For the first objective, I quantified the diets of walleye and smallmouth bass in the lower reaches of Lake Sharpe, a Missouri River reservoir, calculated diet overlap between both predators, and determined whether they partitioned the shared prey based on prey size. I also quantified walleye diets in the upper reach of the reservoir, which has a different prey base and allowed me to examine differential annual growth of walleye within Lake Sharpe. Age-0 gizzard shad Dorosoma cepedianum composed a substantial proportion of diets of both predators, regardless of location, for most of the growing season; patterns in shad growth and vulnerability likely drove observed patterns in diet overlap values. Smallmouth bass consumed a smaller size range of gizzard shad compared to walleye, which consumed a wide range of sizes of shad. Smallmouth bass consumed Sander spp. in some months but in very low quantities (\u3c 5% of diets by weight). Walleye also consumed Sander spp. on rare occasion, and one walleye consumed a smallmouth bass in 2006. Because global climate change is expected to alter population and community dynamics in Great Plains reservoirs, I also used bioenergetics models to assess potential effects of limiting prey availability (specifically, the absence of gizzard shad and rainbow smelt Osmerus mordax) and increased water temperatures (as projected from global climate change models) on walleye and smallmouth bass growth. Scenarios indicated the absence of rainbow smelt from upper Lake Sharpe walleye diets reduced growth, but the absence of gizzard shad would have a marked negative effect on growth of both predators. Bioenergetics scenarios showed increased water temperature would have a negative influence on walleye growth; however, smallmouth bass growth was predicted to increase under increased temperature simulations. For the second objective, I examined relationships between walleye and smallmouth bass population dynamics and demographics in two Missouri River reservoirs and five glacial lakes to indirectly determine whether bass introductions have affected South Dakota walleye populations. I compared relative abundance, size structure, condition, growth, and total annual mortality for both species where available. Of the 26 correlations assessed, only six (23%) were significant (i.e., condition at lakes Francis Case and Poinsett, size structure at Pickerel Lake, relative abundance at lakes Kampeska and Poinsett, and mean length at age 3 at Lake Brant). Importantly, only half of these relationships (i.e., size structure at Pickerel Lake and relative abundance and condition at Lake Kampeska) were negative as would be expected if interspecific competition or predation exists between these two species. The other three significant correlations were positive. While this study does not provide direct observations of competition or consumption, the results of my study did not support the premise that introduced smallmouth bass interfere with walleye population dynamics in South Dakota waters. Rather, other density-dependent and –independent factors likely influence walleye recruitment, growth, and mortality in South Dakota