Abstract Indices of relative abundance are one the most important inputs into a stock assessment model. For many species, we must rely on several indices that routinely conflict with each other and which may result in biased uncertain outputs. Here, explored whether reconciled trends obtained from dynamic factor analysis (DFA) applied to conflicting can be used as trend input We simulated an ag...

During a peak summer for stoats in 1979/80 (density indices in two study areas 8.2 and 10.7 new captures per 100 trapnights) a total of 134 stoats were caught, marked and released (86% young of the year, 58% males). Fifty-seven of 110 stoats were recaptured at least once, of which 42 moved 0.4 1.6 km between first and second captures. Frequency distributions of numbers of captures and first rec...

This paper deals with the sustainable management of a renewable resource based on individual and transferable quotas (ITQs) when agents differ in terms of harvesting costs or catchability. In a dynamic bio-economic model, we determine the conditions under which the manager of an ITQ system can achieve sustainability objectives which simultaneously account for stock renewal, economic efficiency ...

We present a unique view of mackerel (Scomber scombrus) in the North Sea based on a new time series of larvae caught by the Continuous Plankton Recorder (CPR) survey from 1948-2005, covering the period both before and after the collapse of the North Sea stock. Hydrographic backtrack modelling suggested that the effect of advection is very limited between spawning and larvae capture in the CPR s...

The results obtained by two estimators of population sizes, MNKA and Mh, were compared for four species of sma ll mammmais Didelphis ol/rito Wied, 1826, Philollder /relloto (Oilers, 1818), NectolllYs sql/olllipes (Brants, 1827) and Akodon cursor (Wi nge, 1887) during a long-te rm population study. The MNKA estimator consistently underestimated the population sizes in relation to Mh. On the othe...

The strengths and limitations of a Bayesian state-space modelling framework are investigated for a De Lury depletion model that accommodates two recruitment pulses per year. The framework was applied to the Moroccan fishery for common octopus (Octopus vulgaris) between 1982 and 2002. To allow identifiability, natural mortality (M ) and the recruitment rhythm were fixed, and the variance of both...

The Galapagos Islands are a prime example of a place where fishery management policies have been established without first understanding the behavior of fishermen. Since the creation of the Galapagos Marine Reserve in 1998, there has not been a single study in the archipelago that investigates fishing behavior and the factors affecting this behavior. This paper addresses this gap in the literat...

Despite control measures, foodborne outbreaks of non-typhi Salmonella infection continue to occur in developed countries. The authors aimed to assess the number of foodborne Salmonella outbreaks that occurred in France in 1995 using a capture-recapture approach. Data from three sources--the National Public Health Network (NPHN), the Ministry of Agriculture (MA), which receives mandatory notific...