Real options for precautionary fisheries management

The 1996 Food and Agriculture Organization’s (FAO) ‘Guidelines on the Precautionary Approach to Fisheries and Species Introduction’ raise important issues for fisheries managers, but fail to prescribe an approach for risk management. The distinguishing characteristics of the ‘precautionary approach’ are the inclusion of uncertainty and ‘an elaboration on the burden of proof’. The FAO precautionary approach emphasizes that managers should be risk‐averse, but does not provide tools for determining the appropriate degree of risk aversion. Consequently, application of the precautionary approach often leads to decision‐making based on ad hoc safety margins. These safety margins are seldom chosen with explicit consideration of trade‐offs. If the emphasis was shifted to choosing between competing uncertainties, then managers could manage risk. By attempting to avoid risk, managers may gain exposure to other risks and perhaps miss valuable opportunities. We place fishery management problems within the rubric of ‘real investment’ problems, and compare and contrast the consideration of risk by alternative investment frameworks. We show that traditional investment frameworks are inappropriate for fishery management, and furthermore, that traditional precautionary approaches are arbitrary and without basis in decision theory. Quantitative decision‐making techniques, such as formal decision analysis (FDA), enable integration of competing hypotheses that help alleviate burden‐of‐proof issues. These techniques help analysts consider sources of uncertainty. FDA, however, can still be subject to arbitrary safety margins because such analyses often focus on determining which strategies best achieve, or avoid, targets that have been established without complete consideration of trade‐offs. A managerial finance approach, real options analysis (ROA), is an alternative and complementary decision‐making technique that enables managers to compute precautionary adjustments that couple the size of the ‘safety margin’ with the amount of uncertainty, thereby optimizing risk exposure and avoiding the need for arbitrary safety margins. We illustrate the advantages of an approach that combines FDA and ROA, using a heuristic example about a decision to re‐introduce Atlantic salmon (Salmo salar L.) into Lake Ontario. Finally, we provide guidance on applying ROA to other fishery problems. The precautionary approach requires that managers consider risk, but considering risk is not the same as managing it. Here ROA is useful.     

Taking a moment to measure networks—an approach to species conservation

Landscape Ecology - Network-theoretic tools contribute to understanding real-world system dynamics, such as species survival or spread. Network visualization helps illustrate structural...     

Fish pathogen screening and its influence on the likelihood of accidental pathogen introduction during fish translocations

Fish translocations are an important tool in fisheries management, yet translocating fish carries the risk of introducing unwanted pathogens. Although pathogen screening can be a useful tool for managing the risk associated with fish translocations, screening cannot eliminate this risk. This paper addresses these problems by demonstrating that two elements must be considered when designing efficient and effective aquatic pathogen screening programs: (1) how many fish to screen and (2) how long to continue screening programs when repeated testing detects zero infected individuals. The chance that infected fish are translocated despite screening is the joint probability of (1) the failure of the screening to detect infected fish in the sample and (2) the actual presence of infected fish in the translocation batch. Our analysis demonstrates that transfer of an infected fish is most likely to occur at moderately low levels of pathogen prevalence because the probability of detecting at least one infected fish through screening increases as pathogen prevalence increases. Small screening samples (i.e., with a low number of individuals) are most likely to detect infected fish when pathogen prevalence is relatively high (i.e., > 5%). Screening programs should terminate after some number of successive screening events in which no infected individuals have been detected. The number of screening events is a function of the cost of the screening program, the cost of a pathogen translocation, and the probability that an infected fish will be transferred. Furthermore, our analysis indicates that the cost of a disease outbreak has relatively little effect on the length of time the screening program should continue. A more pronounced result is that screening programs that are inexpensive or allow a higher probability of pathogen translocation should be continued longer.     

Modelling angler behaviour as a part of the management system: synthesizing a multi‐disciplinary literature

It is often said that managing fisheries is managing people. This truism implies that fisheries science inherently involves disciplines that focus on fish and their population dynamics, humans and their behaviour, and policy and decision making. This is particularly true for recreational fisheries, where the human behavioural motivation and human response to management actions may be more difficult to predict than in commercial fisheries. We provide a synthesis of the multi‐disciplinary literature on modelling recreational angler behaviour to inform management of recreational fisheries. We begin by defining the recreational fisheries system in an interdisciplinary manner. We then assess the literature for empirical evidence of disciplinary crossover. Using bibliometric data, we provide evidence that there is little disciplinary crossover, particularly between fisheries biology, including applied ecology, and quantitative social science, including economics. We identify critical barriers to disciplinary crossover, such as database indexing issues and nomenclature. Next, we provide a review of critical contributions to the literature, and locate these contributions within our interdisciplinary conceptualization of the recreational fisheries system. This synthesis is intended to be a cross‐disciplinary bridge to facilitate access to the broader literature on modelling angler behaviour, with the ultimate goal of improving recreational fisheries management.     

Normative considerations for recreational fishery management: a bioeconomic framework for linking positive science and normative fisheries policy decisions

Fishery science and management are concerned with both positive, what happens in a fishery system, and normative, what management should do, questions. Rarely are normative criteria discussed as openly and transparently as the positive techniques and assumptions. Instead, normative criteria are often held implicitly, and often goals, and objectives are defined without careful thought about the normative criteria from which such goals, and objectives derive. Management involves three components: system attributes and dynamics, management options and goals and objectives that stem from normative criteria by which outcomes are judged. There is a need to consider normative frameworks and criteria carefully because normative criteria are intrinsic to any management process. This paper motivates the need to consider normative frameworks and criteria carefully, explores issues associated with developing normative frameworks and criteria that articulate positive science, discusses specific issues to consider when developing normative frameworks for recreational fisheries and provides the bioeconomic framework as an example of a normative framework useful for recreational fisheries.