Random-walk dynamics of exploited fish populations

Long Range Dependence and the dynamics of Exploited fish populations

Long range dependence or long memory is a feature of many processes in the natural world, which provides important insights on the underlying mechanisms that generate the observed data. The usual tools available to characterize the phenomenon are mostly based on second order correlations. However, the long memory effects may not be evident at the level of second order correlations and may requi...

Are exploited fish populations stable?

Disentangling the causes of maturation trends in exploited fish populations

Evolutionary theory predicts that selective harvesting will shift the frequency of genes for heritable traits towards those that express well-adapted phenotypes (Law 2007, this Theme Section). Applying this logic, commercial fisheries that select on the basis of size could reasonably be expected to favor the genotype for maturation at smaller sizes (and/or younger ages), given that rapidly matu...

Configuration Space for Random Walk Dynamics

Applied to statistical physics models, the random cost algorithm enforces a Random Walk (RW) in energy (or possibly other thermodynamic quantities). The dynamics of this procedure is distinct from fixed weight updates. The probability for a configuration to be sampled depends on a number of unusual quantities, which are explained in this paper. This has been overlooked in recent literature, whe...

Stabilization of an Exploited Fish Population

Abstract. The purpose of the paper is to design a fishing strategy in order to regulate an exploited fish population. To this end, we use a stagestructured model of a harvested fish population that has been derived in [5]. We give a formula for the fishing effort as a feedback control that allows to stabilize the system. travail réalisé avec la contribution financière du CNCPRST (Maroc) et du C...