Efectes de la prohibició de la pesca esportiva sobre l'estructura poblacional de l'anfós ("Epinephelus marginatus" Lowe, 1834. Pisces, Serranidae) en el Parc Nacional de Cabrera

摘要: catalaL'objectiu d'aquest estudi ha estat mesurar les vacacions en I'estructura poblacional d'Epinephelus marginatus al Parc Nacional de Cabrera, despres la prohibicio activitats pesqueres recreatives el 1991. EIs mostretjos es van desenvolupar mitjanyant censos visuals a dues fondaries (5-10 i 20-25 m) dins I'area protegida localitat Calvia, SW Mallorca, on pesca no esta prohibida, els estius 1993 1994. A I'estiu 1995 tornar mostretjar llocs superficials. Les comparacions per densitat peixos als superficials resultaren unes mitjanes significativament superiors Cabrera. variacions relatives fondaria s'observaren nomes pregons tenir sempre densitats superiors. L'estructura va mostrar una distribucio frequencies talla mes ample anfosos grossos ser abundants, qual cosa repercuti biomassa mitjana, que fou superior respecte Calvia qualsevol fondaria. Durant censar cap individu d 'E. Calvia. Per contra, mitjana romandre constant des fins 1995, mentre desplayar classes grosses, resultant un increment significatiu mitjana. El conjunt d'aquests resultats mostra supervivencia deis recent assentats l'aIrea marina protegida, principalment poca fondaria, revelen I'anomenat "efecte refugi" reserva individus grans amb edat propi estatus proteccio. EnglishThe aim of this study is to assess variations in population structure Epinephelus the National Park after prohibition sport fishing activities since Visual census surveys were carried out at two depths m and during summers 1994 inside protected area near locality where not prohibited. Data for shallow sites also collected summer 1995. Comparisons fish density si tes between either areas showed significant higher means Variations related depth only observed deep had always greater mean densities. The wider size frequency distribution Cabrera large' groupers more abundant consequently, biomass was significantly than any depth. During E. absent In contrast, remained from while displaced towards larger resulting increase biomass. Results show an increased survivorship newly settled mainly they reveal so-called "refuge effect" marine reserve large individuals which can be older protection status itself.