Habitat use and foraging ecology of a batoid community in Shark Bay, Western Australia

Worldwide declines in populations of large elasmobranchs and the potential cascading effects on marine ecosystems have garnered considerable attention. Far less appreciated are the potential ecological impacts of changes in abundances of small to medium bodied elasmobranchs mesopredators. Crucial to elucidating the role of these elasmobranchs is an understanding of their habitat use and foraging ecology in pristine conditions. I investigated the trophic interactions and factors driving spatiotemporal variation in abundances of elasmobranch mesopredators in the relatively pristine ecosystem of Shark Bay, Australia. First, I describe the species composition and seasonal habitat use patterns of elasmobranch mesopredator on the sandflats of Shark Bay. Juvenile batoids dominated this diverse community and were extremely abundant in nearshore microhabitats during the warm season. Stomach content analysis and stable isotopic analysis revealed that there is a large degree of dietary overlap between common batoid species. Crustaceans, which tend to be found in seagrass habitats, dominated diets. Despite isotopic differences between many species, overlap in isotopic niche space was high and there was some degree of individual specialization. I then, investigated the importance of abiotic (temperature and water depth) and biotic (prey and predator abundance) factors in shaping batoid habitat use. Batoids were most abundant and tended to rest in shallow nearshore waters when temperatures were high. This pattern coincides with periods of large shark abundance suggesting batoids were seeking refuge from predators rather than selecting optimal temperatures. Finally, I used acoustic telemetry to examine batoid residency and diel use of the sandflats. Individual batoids were present on the sandflats during both the warm and cold seasons and throughout the diel cycle, suggesting lower sandflat densities during the cold season were a result of habitat shifts rather than migration out of Shark Bay. Combined, habitat use and dietary results suggest that batoids have the potential to seasonally impact sandflat dynamics through their presence, although foraging may be limited on the sandflats. Interestingly, my results suggest that elasmobranch mesopredators in pristine ecosystems probably are not regulated by food supply and their habitat use patterns and perhaps ecosystem impacts may be influenced by their predators.

American Alligator Digestion Rate of Blue Crabs and Its Implications for Stomach Contents Analysis

Stomach contents analysis (SCA) provides a snap-shot observation of a consumer's diet. Interpretation of SCA data can be complicated by many factors, including variation in gastric residence times and digestion rates among prey taxa. Although some SCA methods are reported to efficiently remove all stomach contents, the effectiveness of these techniques has rarely been tested for large irregular shaped prey with hard exoskeletons. We used a controlled feeding trial to estimate gastric residency time and decomposition rate of a large crustacean prey item, the Blue Crab (Callinectes sapidus), which is consumed by American Alligators (Alligator mississippiensis), an abundant apex predator in coastal habitats of the southeastern United States. The decomposition rate of C. sapidus in the stomachs of A. mississippiensis followed a predictable pattern, and some crab pieces remained in stomachs for at least 14 days. We also found that certain portions of C. sapidus were prone to becoming caught within the stomach or esophagus, meaning not all crab parts are consistently recovered using gastric lavage techniques. However, because the state of decomposition of crabs was predictable, it is possible to estimate time since consumption for crabs recovered from wild alligators. This information, coupled with a detailed understanding of crab distributions and alligator movement tactics could help elucidate patterns of cross-ecosystem foraging by the American Alligator in coastal habitats.

Diel and seasonal variation in the use of a nearshore sandflat by a ray community in a near pristine system

Knowledge of movements and habitat use is necessary to assess a species’ ecological role and is especially important for mesopredators because they provide the link between upper and lower trophic levels. Using acoustic telemetry, we examined coarse-scale diel and seasonal movements of elasmobranch mesopredators on a shallow sandflat in Shark Bay, Western Australia. Giant shovelnose rays (Glaucostegus typus) and reticulate whiprays (Himantura uarnak) were most often detected in nearshore microhabitats and were regularly detected throughout the day and year, although reticulate whiprays tended to frequent the monitored array over longer periods. Pink whiprays (H. fai) and cowtail stingrays (Pastinachus atrus) were also detected throughout the day, but were far less frequently detected. Overall, there was no apparent spatial or temporal partitioning of the sandflats, but residency to the area varied between species. In addition, ray presence throughout the year suggests that previously observed differences in seasonal abundance are likely because of seasonal changes in habitat use rather than large-scale migrations. Continuous use of the sandflats and limited movements within this ray community suggests that rays have the potential to be a structuring force on this system and that focusing on nearshore habitats is important for managing subtropical ray populations.

Characteristics of US Graduate Hospitality Programs

The future of hospitality management education and research lies with its graduate programs, especially those offering research-based M.S. and Ph.D. degrees. In response to a need for additional hospitality faculty because of a growing number of programs, the number of graduate programs in the United States has increased substantially in recent years as well. This article presents an overview of graduate hospitality programs in the United States based on the following aspects: (1) program enrollments, admissions and graduation rates, (2) student profiles, (3) program duration and residency requirements, (4) financial support to graduate students, and (5) students’ career opportunities after graduation. Suggestions for future research are provided.

Achievement motivation attributes of international students attending a *postsecondary institution

The purpose of this study was to identify and compare the causal attributes of achievement motivation for academic success possessed by international students to those causal attributes of achievement motivation by other legal immigrant student groups attending a postsecondary institution. In this study, F-1 international students have obtained permission from the federal Department of Immigration and Naturalization Services to attend Miami-Dade Community College in Miami, Florida. There were two additional groups of students selected to participate in this study: Permanent Resident students and Others comprised of asylees, refugees and paroles, which are specific categories of legal immigrant students.^ From the observations of the investigator, international students were more successful at the institution as compared to the other two student groups as measured by such variables as Grade Point Average, Number of Credits Earned and Honors Day awards. By identifying these attributes of achievement motivation, additional curricula, support services and activities can be developed to meet the needs of these highly motivated students.^ Incorporating the theories of McClelland and Weiner in the theoretical framework of the study, both quantitative and qualitative data were collected from 150 subjects using the Measurement of Achievement Motivation Questionnaire and the Guided Biography Interview as data collection instruments. Statistical analyses on the data collected from the three groups of foreign born students at the institution indicated differences in these identified attributes and their effects on academic success.^ Results indicated that F-1 international students at Miami-Dade Community College were highly motivated to achieve, possessed different causal attributes of achievement motivation and displayed their need for achievement in different activities and in different ways as compared to the Permanent Resident and Other student groups. Further investigation on the importance of residency status as an influencing factor of achievement motivation is suggested. ^