Ecological impacts of the austral-most population of Crassostrea gigas in South America: a matter of time?

MARIA M MENDEZ; EVANGELINA SCHWINDT; ALEJANDRO BORTOLUS; ANDREA ROCHE; MATÍAS MAGGIONI; MAITE NARVARTE

ECOLOGICAL RESEARCH

SPRINGER TOKYO

Lugar: Tokyo; Año: 2015 vol. 30 p. 979 - 987

0912-3814

Abstract The Pacific oyster Crassostrea gigas is one ofthe most invasive species worldwide. This oyster has apreponderant ecological role in the invaded environments,for example structuring the benthic communitythrough the provision of micro-habitats. Twenty-fiveyears after its introduction in Argentina, the species iscolonizing new areas along the coast, extending northwardsand southwards its local distribution. In thisstudy, we provide the first ecological characterization ofthe southern-most population of C. gigas; where thecomposition, density, richness and diversity of themacroinvertebrate assemblages associated with zoneswith oysters were compared with zones where it is absentat four different times of the year. Additionally, the mainepibionts taxa settled on the oyster shells were studied.Our results showed differences in the assemblage compositionbetween zones. However, these differences werenot consistent throughout the year. Furthermore, density,richness and diversity were higher in the zones withoysters only in one of the surveys and the parameters didnot differ between zones in the remaining months.Moreover, the majority of oysters were used as settlementsubstrate by the sessile common species present inthe area. Thus, our work provides new informationabout the ecology of C. gigas in recently invaded areasthat enhance our understanding of the role that facilitationplays in physically stressful ecosystems and theimportance that density and time since the invasion mayhave in the engineering effects of the species.