Drivers of variation in occurrence, abundance, and behaviour of sharks on coral reefs.

Quantifying the drivers of population size in reef sharks is critical for the development of appropriate conservation strategies. In north-west Australia, shark populations inhabit coral reefs that border growing centres of human population, industry, and tourism. However, we lack baseline data on reef sharks at large spatial scales (hundreds of km) that might enable managers to assess the status of shark populations in the face of future development in this region. Here, we examined the occurrence, abundance and behaviour of apex (Galeocerdo cuvier, Carcharhinus plumbeus) and reef (C. amblyrhynchos, C. melanopterus, Triaenodon obesus) sharks using > 1200 deployments of baited remote underwater stereo-video systems (stereo-BRUVs) across > 500 km of coastline. We found evidence for species-specific influences of habitat and fishing activities on the occurrence (probability of observation), abundance (MaxN) and behaviour of sharks (time of arrival to the stereo-BRUVs and likelihood of feeding). Although the presence of management zoning (No-take areas) made little difference to most species, C. amblyrhynchos were more common further from boat ramps (a proxy of recreational fishing pressure). Time of arrival for all species was also influenced by distance to boat ramp, although patterns varied among species. Our results demonstrate the capacity for behavioural metrics to complement existing measures of occurrence and abundance in assessing the potential impact of human activities on shark populations.

Quantitative diet analysis of four mesopredators from a coral reef.

The diets of four common mesopredator fishes were examined in the back-reef habitat of a subtropical fringing reef system during the summer months. Quantitative gut content analyses revealed that crustaceans, represented >60% of ingested prey (% mass) by the latticed sand-perch Parapercis clathrata, brown dottyback Pseudochromis fuscus and half-moon grouper Epinephelus rivulatus. Dietary analyses also provided insights into ontogenetic shifts. Juvenile P. fuscus ingested large numbers of crustaceans (amphipods and isopods); these small prey were rarely found in larger individuals (<1% of ingested mass). Fishes also made an important contribution to the diets of all three species representing 10-30% of ingested mass. Conversely, the sand lizardfish Synodus dermatogenys fed exclusively on fishes including clupeids, gobies and labrids. Differences in the gut contents of the four species recorded were not apparent using stable isotope analysis of muscle tissues. The similarity of δ(13) C values in muscle tissues suggested that carbon within prey was derived from primary producers, with comparable carbon isotope signatures to corals and macroalgae, whilst similarities in δ(15) N values indicated that all four species belonged to the same trophic level. Thus, interspecific differences between mesopredator diets were undetectable when using stable isotope analysis which suggests that detailed elucidation of trophic pathways requires gut content analyses.

Critical research needs for managing coral reef marine protected areas: perspectives of academics and managers.

Marine protected areas (MPAs) are a primary policy instrument for managing and protecting coral reefs. Successful MPAs ultimately depend on knowledge-based decision making, where scientific research is integrated into management actions. Fourteen coral reef MPA managers and sixteen academics from eleven research, state and federal government institutions each outlined at least five pertinent research needs for improving the management of MPAs situated in Australian coral reefs. From this list of 173 key questions, we asked members of each group to rank questions in order of urgency, redundancy and importance, which allowed us to explore the extent of perceptional mismatch and overlap among the two groups. Our results suggest the mismatch among MPA managers and academics is small, with no significant difference among the groups in terms of their respective research interests, or the type of questions they pose. However, managers prioritised spatial management and monitoring as research themes, whilst academics identified climate change, resilience, spatial management, fishing and connectivity as the most important topics. Ranking of the posed questions by the two groups was also similar, although managers were less confident about the achievability of the posed research questions and whether questions represented a knowledge gap. We conclude that improved collaboration and knowledge transfer among management and academic groups can be used to achieve similar objectives and enhance the knowledge-based management of MPAs.

Life change and illness onset: importance of concepts for family physicians.

The questions of illness susceptibility and the how and why of the onset of illness are of great concern to family physicians, who are constantly presented with a bewildering array of maladies. This paper presents a model of illness onset as related to life change which is felt to be a highly relevant and useful concept for family physicians. This model has been developed over many years and proposes that illness onset is predictably related to life change, which in turn is a reflection of the amount of coping required. The specific development of these concepts is presented in detail including the development and quantitation of the social readjustment rating scale which quantifies life changes.

Life events: perceptions and frequencies.

Life changes have been associated with illness onset. The Social Readjustment Rating Scale (SRRS) records numerical perceptions of the meaning of life events while the Schedule of Recent Experience (SRE) records the frequency of occurrence of life events. Data on these two instruments from 19 studies done in this laboratory have been surveyed and analyzed. They reveal significant variability among groups in their perceptions of life events as well as in their reports of the frequency of occurrence. Variables indicated to be of significance in either or both of these parameters were age, marital status, sex, socioeconomic status, ethnicity, level of education, culture, and experiencing of an event. These variables impose caution on investigations that relate life changes to illness.

Life events and prisoners.

This study explores retrospectively the relationship of the accumulation of life events as it relates to prison incarceration and extends further the concept that coping with increasing environmental changes results in a variety of overt behaviors. The prison sample comprised 176 male inmates of a federal prison (McNeil Island, Washington) and a state penitentiary (Walla Walla, Washington). Life change scores were derived from the Schedule of Recent Experience (SRE). There was an escalation of annual life change scores of prisoners, indicating the mounting frequency of occurrence of life events prior to incarceration. The SRE may have value in the prediction of socially deviant behavior as with health changes. Variables seen as influencing life change scores were race, age, and education. Analyses of life event frequencies as compared to a normative group indicated that prisoners have evolved a coping life-style that reflects antisocial and criminal behavior.

Impact of a natural catastrophe on life events.

A major earthquake struck Peru in May 1970. This post-quake study compares the impact of this natural catastrophe on the residents of two different cities; one was 90 percent levelled by the quake and one was untouched. A relatively homogeneous population of Peruvians obtained from the two cities completed two paper-and-pencil tests, the Social Readjustment Rating Questionnaire (SRRQ) and the Schedule of Recent Experience (SRE). Both questionnaires were adapted from the SRRQ which had been translated for studies in Spain and EL Salvador. The data from the SRRQ generated two Peruvian Social Readjustment Rating Scales (SRRS), one for each of the cities studied. The differences in the two scales were striking. The lowest intra-cultural correlation yet observed on four studies was obtained. Comparison with a United States population yielded no significant relationships (rs = 0.15), the first time this has occurred in nine intercultural studies. A comparison of the profile of items generated by their subjective magnitude estimations indicated striking qualitative and quantitative differences between the two populations. The SRE generated frequency of occurrence of items and life change magnitudes in five proscribed time intervals. Significant differences in these two quantitative indices (including the health change items) were observed in the two populations in some of the time intervals and not in others. The data formulated suggest that the occurrence of a natural catastrophe--an earthquake which devastated one city--accounted for much of the difference observed between the populations of the two cities.

Psychosocial factors in athletic injuries: development and application of the social and athletic readjustment rating scale (SARRS).

The possible role of psychosocial factors in athletics, namely football injuries, is examined. Initially Holmes and Rahe's Social Readjustment Rating Scale (SRRS) was modified to the Social and Athletic Readjustment Scale (SARRS). Additions to the scale and differences in football players from the general population are discussed. Life change scores over one- and two-year intervals were obtained for college varsity football players. Players suffering major time loss injuries had significantly higher predictive scores than noninjured players.