Development of generalized index-removal models, with particular attention to catchability issues

The index-removal method estimates abundance, exploitation and catchability coefficient, given surveys conducted before and after a known removal. The method assumes a closed population between surveys. Index-removal has seldom been applied due to its strong assumption of constant survey catchabilities. This work generalizes the method to allow multiple years of data to be incorporated, and the assumptions of the original model to be relaxed. If catchability is constant across years, precision can be improved by analyzing multi-year data simultaneously. Two multiple-year models were developed: the first, 1qIR, assumes constant catchability within and among years; the second, 2qIR, allows catchability to change between surveys within years, but assumes survey-specific catchability constant across years. The new models were tested by Monte Carlo simulation then applied to data from two southern rock lobster (Jasus edwardsii) populations. The 1qIR model produced reasonable estimates in one application, but the 2qIR model was required to produce reasonable estimates for the second population. A likelihood ratio test found 1qIR to be the most parsimonious model, even when, the assumption of constant survey catchability appeared to be violated. In that case, diagnostic plots suggested that the 2qIR model provided the most reliable estimates. However, when the constant catchability assumption is tenable, the 1qIR model offers the greatest precision for parameter estimates. Size- and sex-specific heterogeneity of catchability introduces bias in model estimates. Field experiments were performed to test whether the catchability of small lobster was constant for southern rock lobster during two seasons when fishing occurs. No evidence of heterogeneous catchability was observed during the spring. However, significantly more small lobster were caught in control traps and traps seeded with one large adult male lobster than were caught in traps seeded with one large adult female during the summer, when females are preparing to molt and reproduce in Tasmania. Because heterogeneous catchability occurred during the summer, but not the spring, an index of recruitment based on the catch of lobsters one molt size below legal size might be developed for the spring, however, more sampling is needed to resolve the annual timing of sex- and size-specific catchability changes

Simulated climate change impacts on striped bass, blue crab and Eastern oyster in oyster sanctuary habitats of Chesapeake Bay

Oyster reefs and the species that inhabit them will likely be impacted by shifts in environmental conditions due to climate change. This study examined the potential impact of long-term shifts in water temperature and salinity as a result of climate change on the biomasses of important fisheries species within oyster sanctuary sites in the Choptank and Little Choptank river complex (CLC) in Chesapeake Bay using an Ecopath with Ecosim food web model. The model was used to evaluate changes in the oyster reef food web, with particular emphasis on impacts to striped bass (Morone saxatilis), blue crab (Callinectes sapidus), and Eastern oysters (Crassostrea virginica). Eight different climate change scenarios were used to vary water temperature and salinity within Chesapeake Bay up to the year 2100 based on projections given by previous studies. Simulations used a 4 °C increase in temperature along with an increase (+12 or +10) or decrease (−2) in salinity at annual time steps. The rate of change in species biomasses across scenarios ranged from −0.0052 to 0.0008 t/km2/month for striped bass, −0.0021 to 0.0026 t/km2/month for blue crab and −0.0018 to 0.0026 t/km2/month for oysters. Across the majority of scenarios, the biomasses of striped bass and blue crab decreased, while oyster biomass increased. These results begin to offer insight on the interaction between oyster reef restoration benefits and climate change. The modeling framework utilized by this study may be adapted to other systems to assess the effects of climate change on other coastal restoration habitats

Ocean Futures Under Ocean Acidification, Marine Protection, and Changing Fishing Pressures Explored Using a Worldwide Suite of Ecosystem Models

Ecosystem-based management (EBM) of the ocean considers all impacts on and uses of marine and coastal systems. In recent years, there has been a heightened interest in EBM tools that allow testing of alternative management options and help identify tradeoffs among human uses. End-to-end ecosystem modeling frameworks that consider a wide range of management options are a means to provide integrated solutions to the complex ocean management problems encountered in EBM. Here, we leverage the global advances in ecosystem modeling to explore common opportunities and challenges for ecosystem-based management, including changes in ocean acidification, spatial management, and fishing pressure across eight Atlantis (atlantis.cmar.csiro.au) end-to-end ecosystem models. These models represent marine ecosystems from the tropics to the arctic, varying in size, ecology, and management regimes, using a three-dimensional, spatially-explicit structure parametrized for each system. Results suggest stronger impacts from ocean acidification and marine protected areas than from altering fishing pressure, both in terms of guild-level (i.e., aggregations of similar species or groups) biomass and in terms of indicators of ecological and fishery structure. Effects of ocean acidification were typically negative (reducing biomass), while marine protected areas led to both “winners” and “losers” at the level of particular species (or functional groups). Changing fishing pressure (doubling or halving) had smaller effects on the species guilds or ecosystem indicators than either ocean acidification or marine protected areas. Compensatory effects within guilds led to weaker average effects at the guild level than the species or group level. The impacts and tradeoffs implied by these future scenarios are highly relevant as ocean governance shifts focus from single-sector objectives (e.g., sustainable levels of individual fished stocks) to taking into account competing industrial sectors\u27 objectives (e.g., simultaneous spatial management of energy, shipping, and fishing) while at the same time grappling with compounded impacts of global climate change (e.g., ocean acidification and warming)

Molecular medicine and concepts of disease: the ethical value of a conceptual analysis of emerging biomedical technologies

Although it is now generally acknowledged that new biomedical technologies often produce new definitions and sometimes even new concepts of disease, this observation is rarely used in research that anticipates potential ethical issues in emerging technologies. This article argues that it is useful to start with an analysis of implied concepts of disease when anticipating ethical issues of biomedical technologies. It shows, moreover, that it is possible to do so at an early stage, i.e. when a technology is only just emerging. The specific case analysed here is that of ‘molecular medicine’. This group of emerging technologies combines a ‘cascade model’ of disease processes with a ‘personal pattern’ model of bodily functioning. Whereas the ethical implications of the first are partly familiar from earlier—albeit controversial—forms of preventive and predictive medicine, those of the second are quite novel and potentially far-reaching

The Punchline of 'The Joke': The Impact of Process Corruption in the Queensland Police Force, 1957-1987

The Queensland Police Force became virtually synonymous with corruption in the aftermath of the Fitzgerald Inquiry, a judicial examination of police misconduct in that state that took place between 1987 and 1989. While many of the Fitzgerald Inquiry’s findings related to the illicit involvement of police with organised crime, this thesis proposes that it was in fact process corruption that had the greatest impact on the enforcement of law and order in Queensland in the thirty years from 1957 to 1987. It explores process corruption in a variety of forms, from excessive force to the fabrication of evidence, and makes the case that the Queensland Police Force was routinely reliant on procedural misconduct to assert its authority over the community. The thesis examines the way process corruption was exercised against several vulnerable subpopulations in Queensland, including the LGBTQI community, young people, and the protest movement. In doing so, it exposes a systemic pattern of enforcement where process corruption was both tolerated and encouraged by senior police and the conservative government that presided over Queensland in this era