Do efficient small-scale fishers stay active in eras of introducing individual transferable quotas? Evidence from Denmark

Theory suggests the use of individual transferable quotas (ITQs) as a solution to overcapacity and to keep efficient fishers active. While the reduction of overcapacity under ITQ implementation is well documented, empirical evidence on the role of capacity utilisation in adjusting the labour force is scarce. This article analyses whether the capacity utilisation of the vessels that fishers own/work on influences their probability of continuing fishing or whether factors such as fishing income and pension are more important. Danish small-scale fisheries with vessels less than 17 m in length, in which ITQs were introduced in 2007, are studied using a multinomial logit regression based on a unique dataset of individual income and socioeconomic characteristics of Danish fishers in the period 2002-2012 as well as individual vessel data. Together with other relevant socioeconomic variables, vessel capacity utilisation is included in the regression. The latter is identified in a productivity analysis of all commercial active vessels using Data Envelopment Analysis. It is found that increasing vessel capacity utilisation both significantly and positively influences the decision to stay in a small-scale fishery. Increasing income from fisheries also significantly influences the probability of staying in the fishery business. The Danish results provide evidence that the most efficient fishers are those who remain active when ITQs are implemented

Modelling the population and catchability of the southern rock lobster (Jasus edwardsii) in South Australia and Victoria using commercial fisheries catch rate data

The aim of this thesis is to contribute to the field of fisheries science and population modelling, having as subject matter the stocks of southern rock lobster (Jasus edwardsii) exploited by the commercial fisheries of the Southern Zone in South Australia (SZRLF) and the Western Zone in Victoria (WZRLF), Australia. The utility of a statistic known as “catch rate” is explored in regard to inferences drawn about the population and catchability of these southern rock lobster stocks. This thesis is in the form of “by publication” and contains three papers, two of which are published (“Paper One” and “Paper Three”) while one is submitted and under review (“Paper Two”). Studies on some crab and lobster fisheries have shown that natural anomalies in water temperature can substantially impact catch rates. Paper One involved a multivariate regression study of abiotic environmental influences considered to act through catchability on daily catch rates of the SZRLF stock, finding that moon phase, bottom temperature, and wave action were retained in the final model but explained relatively little variance or trend in catch rate. However, the study determined several qualitative outcomes regarding the nature of the influences on catch rates that were not previously reported in the literature for southern rock lobster. Mean catch rate was estimated to be 10% greater just prior to full moon than at new moon, wave height lagged at three days had a positive influence, while bottom temperature and (contemporary) wave height had a negative influence. Similar findings were determined for WZRLF except for moon phase. Paper One compared these outcomes to those from studies on other lobster species, and proposed several hypotheses as explanations. In Paper Two a GLM analysis was performed on WZRLF catch rates that included vessel identifier as a covariate, which represents a fishery influence on catchability, and found that it was substantially more influential on the trend in catch rate than was observed for the environmental influences reported in Paper One. Results suggest that the composition of the WZRLF vessel fleet changed over the years due to vessels exiting from the fishery being on average less efficient at fishing than the rest of the fleet, and hence driving an increase in net catchability and an overly optimistic assessment of the stock. Alternative forms of diagnostic indices were developed to study changes in vessel-driven catchability. The underlying mechanisms of vessel fleet dynamics were investigated and discussed in relation to other fisheries. In Paper Three, novel multi-year depletion models were developed based on extending the Leslie-Davis model. These were applied to data of the SZRLF, producing estimates not only of catchability and yearly trend in relative abundance, but also absolute exploitable abundance and yearly recruitment numbers. Although making strong assumptions about catchability and recruitment for a period in each year, during the rest of the fishing year it avoids the need for such assumptions nor requires fishing effort data. Results compared reasonably with those of a more sophisticated but data hungry integrated stock assessment model.Thesis (Ph.D.) -- University of Adelaide, School of Mathematical Sciences, 201

Operational Research: Methods and Applications

Throughout its history, Operational Research has evolved to include a variety of methods, models and algorithms that have been applied to a diverse and wide range of contexts. This encyclopedic article consists of two main sections: methods and applications. The first aims to summarise the up-to-date knowledge and provide an overview of the state-of-the-art methods and key developments in the various subdomains of the field. The second offers a wide-ranging list of areas where Operational Research has been applied. The article is meant to be read in a nonlinear fashion. It should be used as a point of reference or first-port-of-call for a diverse pool of readers: academics, researchers, students, and practitioners. The entries within the methods and applications sections are presented in alphabetical order. The authors dedicate this paper to the 2023 Turkey/Syria earthquake victims. We sincerely hope that advances in OR will play a role towards minimising the pain and suffering caused by this and future catastrophes

Understanding and mitigating vulnerable bycatch in southern African longline and trawl fisheries

Over the past decade there has been global concern about the bycatch of seabirds, turtles and sharks in fishing operations, in particular longline and trawl fisheries, which have been widely held responsible for their declining population s and threatened conservation status. This thesis addresses the issue of bycatch in a holistic manner, taking into account that species, whether they be target or non-target, do not exist in isolation from each other and their environment. South African fisheries incidentally catch approximately 21 000 seabirds, 165 turtles and 43 000 pelagic sharks per year, including 21 Endangered species. Decreasing CPUE and size-frequency data for Blue Prionace glauca and Short- finned Mako Sharks Isurus oxyrinchus caught in the large pelagic longline fishery suggests exploitation of these species is unsustainable. A decreasing trend in the biomass index was also observed for the Yellow-spotted Catshark Scyliorhinus capensis and the Biscuit Skate Raja. straeleni. An argument for the likelihood of fisheries mortality contributing to the slower than expected turtle population recovery rates is presented, which is supported by results from satellite tracking of Leatherback Turtles Dermochelys coriacea indicating a high degree of overlap with fishing effort. Satellite tracking of Black-browed Thalassarche melanophrys and White-capped T. steadi Albatrosses reveal striking differences in their foraging patterns and presents evidence that Black-browed Albatrosses, in particular, forage to a large extent on natural prey, despite the availability of discards from fishing vessels in the Benguela. Therefore, given the high albatross mortality in the trawl fishery, the benefit of a management decision to limit discarding as a mitigation measure is likely to outweigh the disadvantage of reduced food supply. Reducing bycatch is dependent on the development of effective and relatively inexpensive methods which do not impact on target catches and/or other vulnerable species. In the demersal longline fishery, two methods of optimising line sink rates to reduce seabird bycatch were investigated: increasing mass of weights and decreasing the spacing between weights. This study indicated that while the target species is unlikely to be affected by increased weighting, other vulnerable species of fish and sharks may be affected. Other mitigation experiments investigated line sinking rates and the use of circle hooks in pelagic longline fisheries. The implications of night setting on Swordfish Xiphias gladius catches, fishery closure during full moon and the appropriateness of the international standard 5% fin to trunk ratio for the South African fishery, were also investigated. Lastly, the spatial and temporal overlap of catches of seabirds, turtles and sharks were investigated through a conservation planning exercise using MARXAN and potential areas for closure identified

Integrated ecological–economic fisheries models—Evaluation, review and challenges for implementation

Marine ecosystems evolve under many interconnected and area-specific pressures. To fulfil society's intensifying and diversifying needs while ensuring ecologically sustainable development, more effective marine spatial planning and broader-scope management of marine resources is necessary. Integrated ecological-economic fisheries models (IEEFMs) of marine systems are needed to evaluate impacts and sustainability of potential management actions and understand, and anticipate ecological, economic and social dynamics at a range of scales from local to national and regional. To make these models most effective, it is important to determine how model characteristics and methods of communicating results influence the model implementation, the nature of the advice that can be provided and the impact on decisions taken by managers. This article presents a global review and comparative evaluation of 35 IEEFMs applied to marine fisheries and marine ecosystem resources to identify the characteristics that determine their usefulness, effectiveness and implementation. The focus is on fully integrated models that allow for feedbacks between ecological and human processes although not all the models reviewed achieve that. Modellers must invest more time to make models user friendly and to participate in management fora where models and model results can be explained and discussed. Such involvement is beneficial to all parties, leading to improvement of mo-dels and more effective implementation of advice, but demands substantial resources which must be built into the governance process. It takes time to develop effective processes for using IEEFMs requiring a long-term commitment to integrating multidisciplinary modelling advice into management decision-making.</p

Operational Research: Methods and Applications

Throughout its history, Operational Research has evolved to include a variety of methods, models and algorithms that have been applied to a diverse and wide range of contexts. This encyclopedic article consists of two main sections: methods and applications. The first aims to summarise the up-to-date knowledge and provide an overview of the state-of-the-art methods and key developments in the various subdomains of the field. The second offers a wide-ranging list of areas where Operational Research has been applied. The article is meant to be read in a nonlinear fashion. It should be used as a point of reference or first-port-of-call for a diverse pool of readers: academics, researchers, students, and practitioners. The entries within the methods and applications sections are presented in alphabetical order

Design and performance evaluation of failure prediction models

Prediction of corporate bankruptcy (or distress) is one of the major activities in auditing firms’ risks and uncertainties. The design of reliable models to predict distress is crucial for many decision-making processes. Although a variety of models have been designed to predict distress, the relative performance evaluation of competing prediction models remains an exercise that is unidimensional in nature. To be more specific, although some studies use several performance criteria and their measures to assess the relative performance of distress prediction models, the assessment exercise of competing prediction models is restricted to their ranking by a single measure of a single criterion at a time, which leads to reporting conflicting results. The first essay of this research overcomes this methodological issue by proposing an orientation-free super-efficiency Data Envelopment Analysis (DEA) model as a multi-criteria assessment framework. Furthermore, the study performs an exhaustive comparative analysis of the most popular bankruptcy modelling frameworks for UK data. Also, it addresses two important research questions; namely, do some modelling frameworks perform better than others by design? and to what extent the choice and/or the design of explanatory variables and their nature affect the performance of modelling frameworks? Further, using different static and dynamic statistical frameworks, this chapter proposes new Failure Prediction Models (FPMs). However, within a super-efficiency DEA framework, the reference benchmark changes from one prediction model evaluation to another one, which in some contexts might be viewed as “unfair” benchmarking. The second essay overcomes this issue by proposing a Slacks-Based Measure Context-Dependent DEA (SBM-CDEA) framework to evaluate the competing Distress Prediction Models (DPMs). Moreover, it performs an exhaustive comparative analysis of the most popular corporate distress prediction frameworks under both a single criterion and multiple criteria using data of UK firms listed on London Stock Exchange (LSE). Further, this chapter proposes new DPMs using different static and dynamic statistical frameworks. Another shortcoming of the existing studies on performance evaluation lies in the use of static frameworks to compare the performance of DPMs. The third essay overcomes this methodological issue by suggesting a dynamic multi-criteria performance assessment framework, namely, Malmquist SBM-DEA, which by design, can monitor the performance of competing prediction models over time. Further, this study proposes new static and dynamic distress prediction models. Also, the study addresses several research questions as follows; what is the effect of information on the performance of DPMs? How the out-of-sample performance of dynamic DPMs compares to the out-of-sample performance of static ones? What is the effect of the length of training sample on the performance of static and dynamic models? Which models perform better in forecasting distress during the years with Higher Distress Rate (HDR)? On feature selection, studies have used different types of information including accounting, market, macroeconomic variables and the management efficiency scores as predictors. The recently applied techniques to take into account the management efficiency of firms are two-stage models. The two-stage DPMs incorporate multiple inputs and outputs to estimate the efficiency measure of a corporation relative to the most efficient ones, in the first stage, and use the efficiency score as a predictor in the second stage. The survey of the literature reveals that most of the existing studies failed to have a comprehensive comparison between two-stage DPMs. Moreover, the choice of inputs and outputs for DEA models that estimate the efficiency measures of a company has been restricted to accounting variables and features of the company. The fourth essay adds to the current literature of two-stage DPMs in several respects. First, the study proposes to consider the decomposition of Slack-Based Measure (SBM) of efficiency into Pure Technical Efficiency (PTE), Scale Efficiency (SE), and Mix Efficiency (ME), to analyse how each of these measures individually contributes to developing distress prediction models. Second, in addition to the conventional approach of using accounting variables as inputs and outputs of DEA models to estimate the measure of management efficiency, this study uses market information variables to calculate the measure of the market efficiency of companies. Third, this research provides a comprehensive analysis of two-stage DPMs through applying different DEA models at the first stage – e.g., input-oriented vs. output oriented, radial vs. non-radial, static vs. dynamic, to compute the measures of management efficiency and market efficiency of companies; and also using dynamic and static classifier frameworks at the second stage to design new distress prediction models

Embracing Analytics in the Drinking Water Industry

Analytics can support numerous aspects of water industry planning, management, and operations. Given this wide range of touchpoints and applications, it is becoming increasingly imperative that the championship and capability of broad-based analytics needs to be developed and practically integrated to address the current and transitional challenges facing the drinking water industry. Analytics will contribute substantially to future efforts to provide innovative solutions that make the water industry more sustainable and resilient. The purpose of this book is to introduce analytics to practicing water engineers so they can deploy the covered subjects, approaches, and detailed techniques in their daily operations, management, and decision-making processes. Also, undergraduate students as well as early graduate students who are in the water concentrations will be exposed to established analytical techniques, along with many methods that are currently considered to be new or emerging/maturing. This book covers a broad spectrum of water industry analytics topics in an easy-to-follow manner. The overall background and contexts are motivated by (and directly drawn from) actual water utility projects that the authors have worked on numerous recent years. The authors strongly believe that the water industry should embrace and integrate data-driven fundamentals and methods into their daily operations and decision-making process(es) to replace established ìrule-of-thumbî and weak heuristic approaches ñ and an analytics viewpoint, approach, and culture is key to this industry transformation

\u3ci\u3eThe Conference Proceedings of the 1999 Air Transport Research Group (ATRG) of the WCTR Society, Volume 2 \u3c/i\u3e

UNOAI Report 99-6https://digitalcommons.unomaha.edu/facultybooks/1148/thumbnail.jp