Possible link between prey quality, condition and growth of juvenile hake (Merluccius merluccius) in the Gulf of Lions (NW Mediterranean)

The energy value of the main prey and the growth of juvenile hake in the Gulf of Lions were analysed to determine whether fish condition could be linked to difference in prey quality and resulted in growth difference. Large differences in energy content (15.6 to 23.6 kJ g-1 DW) among prey types were recorded with low values found in amphipods and natantid shrimps, intermediate values in euphausiids and mysids, and high values in fish. High condition in juvenile hake was linked to the consumption of prey with high energy content. However, no difference in fish growth was observed by the analysis of otolith micro-increments

Implementation of an end-to-end model of the Gulf of Lions ecosystem (NW Mediterranean Sea). I. Parameterization, calibration and evaluation

International audienc

Evaluation visuelle des peuplements et populations de poissons : méthodes et problèmes

Following the symposium held in June 1984 at Port Cros, the methods of underwater observation of fish communities and populations are critically reviewed. Particular emphasis is laid upon the possible causes of bias, and the ways of circumventing them. Given some necessary precautions and adequate training, and within definite limits, underwater observations and counts can produce highly reliable results, not obtainable by «blind» techniques. Some examples are given, based upon the personal experiences of the participants, both in the Mediterranean and the Indo-Pacific.Harmelin-Vivien M. L., Harmelin J.G., Chauvet Claude, Mellon-Duval Capucine, Galzin R., Lejeune P., Barnabé Gilbert, Blanc Françoise, Chevalier R., Duclerc Jean, Lasserre G. Evaluation visuelle des peuplements et populations de poissons : méthodes et problèmes. In: Revue d'Écologie (La Terre et La Vie), tome 40, n°4, 1985. pp. 467-539