Fishery dependent data--length distributions, sex ratios, maturity schedules, and species composition of landed catches--are necessary for stock assessments. These data are currently collected by state port biologists using a sampling design that randomly selects samples from a small percentage of a very large target population. Sampling programs may need to...
Depletion-Based Stock Reduction Analysis (DB-SRA; Dick and MacCall, 2011) is a catch-only fisheries stock assessment model that has been developed to estimate an overfishing limit (OFL) in data-poor situations. DB-SRA projects the biomass trajectories of a stock by means of a catch time series and five parameters: the instantaneous, per...
This paper examines the viability of the management of a transboundary resource, the Bay of Biscay anchovy (Engraulis encrasicolus L.). A deterministic model is used to simulate the anchovy dynamics, with the fish stock consisting of two age groups, “young" and “old", while recruitment follows a Beverton Holt pattern. Two...
Price instruments are rarely seen in fisheries despite their many desirable
properties. In this paper, I find new reasons to favor price instruments in a
fishery. Given constraints on information and enforcement precluding the
optimum optimorum, I consider a second-best but welfare improving
policy when catch limits cannot be enforced...
Statistical modeling has evolved around building increasingly more complex models, even though it is common knowledge among statisticians that an optimal model size usually exists for any given data set. Having overly complex models leads to imprecise parameter estimates and tends to increase the subjective role of the modeler, which...
Stock assessments for many U.S. Pacific coast groundfish stocks are developed using the catch-at-age method known as Stock Synthesis. In this work a simulation package was developed and used to evaluate the sensitivity of the Stock Synthesis program. More specifically, the evaluation focused on the impacts of input data errors...
The international council for the exploration of the seas (ICES) publish
annual reports on fish stock assessments. Based on the stock assessment
data for the North-East Arctic cod we estimate the effective fishing
mortality, establishing coefficients for the catchability-at-age and the
annual fishing effort. The fishing effort estimates are then...
This paper discusses the use of resource assessment surveys as the basis for effective fisheries management drawing on the resource assessment survey of the Arabian Sea coast of Oman. This survey, completed in 2009, has been undertaken in the context of the primary aim of the Oman Ministry of Fisheries...
Stock assessment techniques currently used in the United States are extremely costly to implement, involve significant data requirements, and are inaccessible to all but a few stock assessment scientists. A systematic decrease in fishery yields and the designation of several species as overfished on the west coast of the United...