MEPS 160:135-147 (1997)  -  doi:10.3354/meps160135

Mortality of juvenile fishes of the genus Diplodus in protected and unprotected areas in the western Mediterranean Sea

E. Macpherson1,*, F. Biagi2, P. Francour3, A. García-Rubies1, J. Harmelin4, M. Harmelin-Vivien4, J. Y. Jouvenel5, S. Planes5, L. Vigliola4, L. Tunesi6

1Centro de Estudios Avanzados de Blanes (CSIC), Cami de Santa Barbara s/n, E-17300 Blanes, Girona, Spain
2Dipartimento di Scienze dell'Uomo e dell'Ambiente, Universita di Pisa, Via A. Volta 6, I-5600 Pisa, Italy
3GIS Posidonie, Parc Scientifique et Technique de Luminy, Case 901, F-13288 Marseille Cedex 09, France
4Centre d'Océanologie de Marseille, CNRS UMR DIMAR, Station Marine d'Endoume, F-13007 Marseille, France
5Ecole Pratique des Hautes Etudes, URA 1453 CNRS, Université de Perpignan, F-66860 Perpignan Cedex, France
6ICRAM, Via L. Respighi 5, I-00197 Roma, Italy

Mortality patterns from peak of settlement to dispersal from the nursery area, concurrently with integration of juveniles into adult populations, of 3 littoral fishes of the genus Diplodus (D. puntazzo, D. sargus, and D. vulgaris) (Family Sparidae) were studied between May 1993 and June 1996. Twenty-one stations were censused weekly, weather conditions permitting, along the Mediterranean coasts of Spain, France, and Italy. Eight stations were located in protected areas and 13 in unprotected zones. Declines in abundance in all 3 species were particularly marked in the first month after settlement. Patterns of survivorship indicated that the 3 species were subject to density-dependent mortality from settlement to recruitment to the adult population. The effect of this mortality pattern was to reduce the variability in year-class strength, though without changing the rank order of abundance between years. The mortality rates for D. sargus were higher than for D. puntazzo and D. vulgaris. The results of this study indicated that mortality rates in protected areas did not differ significantly from those in unprotected zones, suggesting that marine reserves are not necessarily a sink for post-settlement fishes.

Mortality · Fish settlement · Diplodus · Marine reserves

Full text in pdf format