Denis Rivard

Bio: Denis Rivard is an academic researcher. The author has contributed to research in topics: Fisheries management & Strengths and weaknesses. The author has an hindex of 1, co-authored 1 publications receiving 289 citations.

Risk evaluation and biological reference points for fisheries management

Abstract: This volume contains 31 papers presented in three theme sessions by fisheries scientists from around the world at a Department of Fisheries and Oceans' workshop in 1991 Papers presented address the use, strengths and weaknesses of commonly-used biological reference points; methods for identifying and quantifying uncertainties associated with using various reference points; and alternative management strategies or suggested strategies for dealing with novel situations Answers to specific questions relating to fisheries management, compiled by four working groups at the workshop, are included, as well as a list of participants

Fisheries stock assessment and decision analysis: the Bayesian approach

Abstract: The Bayesian approach to stock assessment determines the probabilities of alternative hypotheses using information for the stock in question and from inferences for other stocks/species. These probabilities are essential if the consequences of alternative management actions are to be evaluated through a decision analysis. Using the Bayesian approach to stock assessment and decision analysis it becomes possible to admit the full range of uncertainty and use the collective historical experience of fisheries science when estimating the consequences of proposed management actions. Recent advances in computing algorithms and power have allowed methods based on the Bayesian approach to be used even for fairly complex stock assessment models and to be within the reach of most stock assessment scientists. However, to avoid coming to ill-founded conclusions, care must be taken when selecting prior distributions. In particular, selection of priors designed to be noninformative with respect to quantities of interest to management is problematic. The arguments of the paper are illustrated using New Zealand's western stock of hoki, Macruronus novaezelandiae (Merlucciidae) and the Bering--Chukchi--Beaufort Seas stock of bowhead whales as examples

Early life history and recruitment in fish populations

Abstract: The early life history of fishes and its role in recruitment processes. Recruitment in fish populations: the paradigm shift generated by ICES committee A. Parent-progeny relationships. Selective processes in the early life history. The contribution of early life history studies to our understanding of recruitment. Conclusions.

Principles for the design of marine reserves

Abstract: The theory underlying the design of marine reserves, whether the goal is to preserve biodiversity or to manage fisheries, is still in its infancy. For both of these goals, there is a need for general principles on which to base marine reserve design, and because of the paucity of empirical experience, these principles must be based on models. However, most of the theoretical studies to date have been specific to a single situation, with few attempts to deduce general principles. Here we attempt to distill existing results into general principles useful to designers of marine reserves. To answer the question of how fishery management using reserves compares to conventional management, we provide two prin- ciples: (1) the effect of reserves on yield per recruit is similar to increasing the age of first capture, and (2) the effect of reserves on yield is similar to reducing effort. Another two principles answer the question of how to design reserve configurations so that species with movement in various stages will be sustainable: (3) higher juvenile and adult movement lowers sustainability of reserves for biodiversity, but an intermediate level of adult move- ment is required for reserves for fishery management, and (4) longer larval dispersal distance requires larger reserves for sustainability. These principles provide general guidelines for design, and attention to them will allow more rapid progress in future modeling studies. Whether populations or communities will persist under any specific reserve design is un- certain, and we suggest ways of dealing with that uncertainty.