Empirical equations for the estimation of natural mortality in Mediterranean teleosts

Empirical relationships were established linking estimates of the instantaneous rate of natural mortality (M), the von Bertalanffy growth parameters, L sub( infinity ) (or W sub( infinity )) and K, and annual mean water temperature in 56 stocks of Mediterranean teleosts fish. It is suggested that these relationships generate for these fish more reliable estimates of M than the widely-used model of Pauly (1980, J. Cons. CIEM 33(3):175-192), which was based on 175 fish stocks, but included only five stocks from the Mediterranean

Empirical equations for the estimation of natural mortality in Mediterranean teleosts

Natural mortality, Statistical analysis, Mediterranean Region, Teleostei

CARI'96 : actes du 3ème colloque africain sur la recherche en informatique = CARI'96 : proceedings of the 3rd African conference on research in computer science

Cet article présente quelques solutions ayant pour but d'améliorer la testabilité des circuits combinatoires testés de manière pseudo-aléatoire. S'inscrivant dans l'approche Force-Observe, les solutions préconisées consistent en la modification des circuits par l'insertion de deux types de points de test : les points d'observation et les points de contrôle. (Résumé d'auteur

Foraging behaviour of satellite-tracked king penguins in relation to sea surface temperature obtained by satellite telemetry at Crozet Archipelago, a study during three austral summers

We investigated the foraging behaviour of king penguins in relation to sea-surface temperature distribution over 3 years near the Crozet Arckipelago, South Indian Ocean. Within their range there are 2 hydrographic frontal systems, whose seasonal patterns of productivity are predictable. These are the Polar Front and the Sub-Antarctic Front. During the austral summer the foraging range of breeding king penguins was restricted to the Polar Frontal Zone, limited to the south by the Polar Front and to the north by the Sub-Antarctic Front. Most birds travelled towards the colder water situated south of Crozet, while other birds moved east to warmer water. Birds travelling south spent more time than expected in the coldest waters generally associated with the Polar Front. Birds travelling east reached the southern limit of the Sub-Antarctic Front (sea-surface temperature between 8 and 10 degrees C). Within the Polar Frontal Zone birds differed in their foraging behaviour, with incubating birds remaining at sea for longer times and covering longer distances. During the incubation period, king penguins travelling south tended to spend their time in areas with a sea-surface temperature between 4 and 5 degrees C, which coincide with the location of the Polar Front. Though these birds remained at sea longer, they did not go any further south than birds having an egg ready to hatch or than birds in the brooding period, which appeared to travel more directly towards the Polar Front, As the breeding season progressed, the Polar Front moved further south, out of the range of the king penguins especially those with a newly hatched chick that were limited in the amount of time that they could spend at sea. King penguins breeding at Crozet may choose between 2 strategies, in which some birds forage towards the Sub-Antarctic Front but most travel south towards the Polar Front.</p