BECAS
BARRENA MaitÉ Aneley
artículos
Título:
Distribution, abundance, and size structure of the Pacifil cupped oyster, Magallana gigas (Thunberg, 1783), from nothern Patagonia
Autor/es:
LEANDRO ANDRÉS HUNICKEN; RAÚL ALBERTO GONZÁLES; DENNIS NORBERTO LANDETE; MAITÉ ANELEY BARRENA; JUAN FRANCISCO SAAD; MAITE ANDREA NARVARTE
Revista:
Marine and Fishery Sciences
Editorial:
INIDEP
Referencias:
Año: 2023
ISSN:
2683-7951
Resumen:
In the 1980s, the oyster Magallana gigas was deliberately introduced in Northern ArgentineanPatagonia (Bahía Anegada, BA) and expanded 80 km south of the Río Negro estuary on the coast ofEl Cóndor (EC) in 2004. Although oysters have demonstrated dispersal capability, there is a dearthof data regarding the EC population since 2011. This research focusses on the present M. gigaspopulation encompassing distribution, abundance, and size structure along a 180-kilometer coastalstretch from EC to San Antonio Este (SAE). Subsequently, we compared these data with those forthe BA population. The presence of M. gigas in Río Negro was detected in three sites near ElCóndor (EC, Piedras Verdes -PV- and El Pescadero) and San Antonio Bay. The estimatedabundances in EC were low (between 1.8 10 -3 ind m -2 and 9 10 -2 ind m -2 ), in contrast to those at BA(105 ± 2 ind m -2 ). Presence in SAE was only limited to one site and three adults M. gigasindividuals. The BA oyster population exhibited a multimodal distribution, with a significantnumber of young oysters, whereas the Piedras Verdes (PV) region displayed a trimodal structuredominated by larger specimens. In EC, owing to the limited number of individuals, modalcomponents were less discernible, but small oysters predominated. The current abundance of M.gigas in EC was considerably lower than that in 2011, indicating a population decline. Despite this,the presence of juvenile oysters suggests recent recruitment, emphasizing species resilience. Theseresults show that M. gigas faces challenges when attempting to establish itself in this specificregion. Studying the underlying causes would help to understand the factors that limit the expansionof a species considered to be a global invader.
