Captura incidental de invertebrados en bancos de pesca de vieira patagónica: un caso de estudio con datos obtenidos por el Programa Observadores a Bordo
The reproductive cycle of Zygochlamys patagonica was studied from October 1999 to February 2001 in a bed located in the south-western Atlantic (Reclutas bed 39°24′ S–55°56′W). Scallops were collected monthly and the sexual maturity stages were determined histologically (N = 508). Sex-ratio was 1:1 (t-test P > 0.05). The size of first sexual maturity was estimated from males of an average of 36.63 mm and females of 36.31 mm of shell height. The relative gonadal condition index (RGCI) showed an annual cycle, with higher values during winter–spring and lower values during summer–autumn; an inverse relationship for the relative muscle condition index (RMCI) was observed with maximum values in early summer. Thus, a reallocation of energy from soma to gonad appears to be inevitable to meet energy demand of gonad development. Seven histological stages of sexual maturity were established for both sexes: (1) immature; (2) early maturity; (3) advanced maturity,;(4) ripe; (5) spawning; (6) spent; and (7) recovery. Individuals in early and advanced maturity were found throughout the year; however, they were found more frequently between June and September. Spawning began in October (early spring) and extended through March (late summer–early autumn) coexisting with early and advanced maturity stages supported by the annual variation of the RGCI and the food availability into the system.
La pesquería bentónica más importante en extensión y producción del Atlántico Sudoccidental es la de vieira patagónica (Zygochlamys patagonica). La desarrollan cuatro buques factoría con redes de arrastre de fondo no selectivas y planta procesadora a bordo. Durante el proceso de selección se retienen las vieiras de talla comercial (≥ 55 mm de alto total) y las que no la alcanzan (< 55 mm AT) se descartan al mar. El objetivo del presente trabajo fue determinar el nivel de supervivencia de los ejemplares descartados al mar y el efecto del proceso de selección a bordo. Se seleccionaron vieiras de talla no comercial procedentes de cubierta (control) y descarte (tratamiento). Se las clasificó de acuerdo con el nivel de daño y se las colocó en bolsas de polipropileno para fondearlas (~ 100 m de profundidad). Cuando se recuperaron los fondeos, a los 10 y 54 d, se contabilizó la cantidad de individuos vivos en cada bolsa. Los mayores niveles de supervivencia se registraron en ejemplares sin daño o con daño solo en los bordes; en aquellos con roturas o perforaciones en la valva el porcentaje fue cercano al 50%. Se observó que la supervivencia disminuía a medida que aumentaba el tiempo de la experiencia.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.