Environmental characterization of seasonal trends and foraging habitat of bottlenose dolphins (Tursiops truncatus) in northern Gulf of Mexico bays

A description of the foraging habitat of a cetacean species is critical for conservation and effective management. We used a fine-scale microhabitat approach to examine patterns in bottlenose dolphin (Tursiops truncatus) foraging distribution in relation to dissolved oxygen, turbidity, salinity, water depth, water temperature, and distance from shore measurements in a highly turbid estuary on the northern Gulf of Mexico. In general, environmental variation in the Barataria Basin marine environment comprises three primary axes of variability (i.e., factors: temperature and dissolved oxygen, salinity and turbidity, and distance and depth) that represent seasonal, spatial-seasonal, and spatial scales, respectively. Foraging sites were differentiated from nonforaging sites by significant differences among group size, temperature, turbidity, and season. Habitat selection analysis on individual variables indicated that foraging was more frequently observed in waters 4–6 m deep, 200–500 m from shore, and at salinity values of around 20 psu. This fine-scale and multivariate approach represents a useful method of exploring the complexity, gradation, and detail of the relationships between environmental variables and the foraging distribution patterns of bottlenose dolphin

Formation of a Stress-Induced Check Mark on the Otoliths of Juvenile Fishes: Implications for Mesocosm Studies

Daily otolith increment widths of spot Leiostomus xanthurus and spotted seatrout Cynoscion nebulosus were examined experimentally in field mesocosms for 5 to 7 days in various habitat types. Daily otolith increments were used as a surrogate for daily somatic growth so that growth prior to capture and handling could be examined. For both species, possible effects of habitat types were confounded by an overall decrease in daily increment widths during the experimental period when compared to increment widths prior to capture. Several spotted seatrout inadvertently captured during mesocosm deployment provided a means for assessing if there was a significant mesocosm effect or if capture and handling may have caused the decreased increment widths. These “volunteers” were distinguishable from experimental fish by the occurrence of a check mark on the otoliths of the experimental fish. Because experimental increment widths of “volunteers” were not different from pre-experimental widths, handling rather than caging effects appeared responsible for reduced increment widths. While there appeared to be no “mesocosm” effect, handling stress potentially affected growth longer than the 24 h acclimation period we anticipated. Short-term effects of capture and handling of wild fish for mesocosm use should be explored and accounted for in future studies

The Lantern Vol. 43, No. 2, May 1977

• Ode to Loneliness • Windy Grief! • Death • The Icicle Vase • To Ellen • The Arrival of Night • The Reserve Clause • The Unspoken War • Bull\u27s Eye • Closing Scene • Brown Bottle Candles • Goodbye • There\u27s Individuality In The Surf • Impermanence • Dark Nightshttps://digitalcommons.ursinus.edu/lantern/1110/thumbnail.jp

Energy and system size dependence of \phi meson production in Cu+Cu and Au+Au collisions

We study the beam-energy and system-size dependence of \phi meson production (using the hadronic decay mode \phi -- K+K-) by comparing the new results from Cu+Cu collisions and previously reported Au+Au collisions at \sqrt{s_NN} = 62.4 and 200 GeV measured in the STAR experiment at RHIC. Data presented are from mid-rapidity (|y|<0.5) for 0.4 < pT < 5 GeV/c. At a given beam energy, the transverse momentum distributions for \phi mesons are observed to be similar in yield and shape for Cu+Cu and Au+Au colliding systems with similar average numbers of participating nucleons. The \phi meson yields in nucleus-nucleus collisions, normalised by the average number of participating nucleons, are found to be enhanced relative to those from p+p collisions with a different trend compared to strange baryons. The enhancement for \phi mesons is observed to be higher at \sqrt{s_NN} = 200 GeV compared to 62.4 GeV. These observations for the produced \phi(s\bar{s}) mesons clearly suggest that, at these collision energies, the source of enhancement of strange hadrons is related to the formation of a dense partonic medium in high energy nucleus-nucleus collisions and cannot be alone due to canonical suppression of their production in smaller systems.Comment: 20 pages and 5 figure

QCD and strongly coupled gauge theories : challenges and perspectives

We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.Peer reviewe

Environmental characterization of seasonal trends and foraging habitat of bottlenose dolphins (Tursiops truncatus) in northern Gulf of Mexico bays

A description of the foraging habitat of a cetacean species is critical for conservation and effective management. We used a fine-scale microhabitat approach to examine patterns in bottlenose dolphin (Tursiops truncatus) foraging distribution in relation to dissolved oxygen, turbidity, salinity, water depth, water temperature, and distance from shore measurements in a highly turbid estuary on the northern Gulf of Mexico. In general, environmental variation in the Barataria Basin marine environment comprises three primary axes of variability (i.e., factors: temperature and dissolved oxygen, salinity and turbidity, and distance and depth) that represent seasonal, spatial-seasonal, and spatial scales, respectively. Foraging sites were differentiated from nonforaging sites by significant differences among group size, temperature, turbidity, and season. Habitat selection analysis on individual variables indicated that foraging was more frequently observed in waters 4-6 m deep, 200-500 m from shore, and at salinity values of around 20 psu. This fine-scale and multivariate approach represents a useful method of exploring the complexity, gradation, and detail of the relationships between environmental variables and the foraging distribution patterns of bottlenose dolphin

Hydrophone identiflcation and charaderization of Cynoscion squamipinnis (Perciformes: Sciaenidae) spawning sites in the Gulf of Nicoya, Costa Rica

A hydrophone survey of the northem Gulf of Nicoya was conducted to identify spawning sites used by the corvina aguada (Cynoscíon squamapinnis). Between July 14, and July 17, 1992, thirty-one stations were surveyed during late aftemoon and evening hours. Large aggregations of drumming corvina were located as early as 1606 hrs, but were generally restricted to stations characterized by aboye average depth and moving water. Drumming activity by C. squamapinnis peaked between 1655 and 1910 hrs on four evenings and fully subsided by about 2\00 hrs. In a stepwise regression model, five variables were selected to predict sound intensity. The overall model was statistically significant (P &lt; 0.0001) and explained a high proportion of the variance (R-square = 0.59). The five variables included in the model, in order of decreasing partial R-squares, were tide2 (0.2103), hour3 (0.1470), temperature2 (0.1051), substrate (0.0720), and salinity2 (0.0562). Local gillnet fishermen are familiar with corvina sound production behavior and sorne can identify the drumming species. Corvina fishing takes place only during periods known locally as "mareas de corvina" (Corvina tides), which are those that occur irnmediately after the highest (or lowest) tides of the month, and which gillnet fishermen claim to be the best for fishing. Thus, heaviest fishing concentrates in a period of eight to ten days a month, and we also suspect that fishing during "corvina tides" is focused on natural drumming aggregations. Under present management, the fishery may be reducing natural spawning success and maximizing effort by coinciding temporally with natural spawning aggregations.A hydrophone survey of the northem Gulf of Nicoya was conducted to identify spawning sites used by the corvina aguada (Cynoscíon squamapinnis). Between July 14, and July 17, 1992, thirty-one stations were surveyed during late aftemoon and evening hours. Large aggregations of drumming corvina were located as early as 1606 hrs, but were generally restricted to stations characterized by aboye average depth and moving water. Drumming activity by C. squamapinnis peaked between 1655 and 1910 hrs on four evenings and fully subsided by about 2\00 hrs. In a stepwise regression model, five variables were selected to predict sound intensity. The overall model was statistically significant (P &lt; 0.0001) and explained a high proportion of the variance (R-square = 0.59). The five variables included in the model, in order of decreasing partial R-squares, were tide2 (0.2103), hour3 (0.1470), temperature2 (0.1051), substrate (0.0720), and salinity2 (0.0562). Local gillnet fishermen are familiar with corvina sound production behavior and sorne can identify the drumming species. Corvina fishing takes place only during periods known locally as "mareas de corvina" (Corvina tides), which are those that occur irnmediately after the highest (or lowest) tides of the month, and which gillnet fishermen claim to be the best for fishing. Thus, heaviest fishing concentrates in a period of eight to ten days a month, and we also suspect that fishing during "corvina tides" is focused on natural drumming aggregations. Under present management, the fishery may be reducing natural spawning success and maximizing effort by coinciding temporally with natural spawning aggregations