Abstract

In late summer 2009, an intense Alexandrium catenella bloom occurred in the mouth of Aysén fjord , Chile (45º 06’ S, 73 º 30’ W). The concentration found in the first 10 m depth in peak phase was 396 103 cell l-1. Three sampling sites were established to study the potentiality of nets and mussels as A. catenella cysts captors. During the bloom decline, twenty days after, commercial size mussels (Mytilus chilensis) and nets taken both from a place free of this dinoflagellate were placed in the water column. At each site three nets were suspended at 5, 10 and 15 m depth while the three net cages with 35 mussels each were placed at 10 m depth. Both were moored for 30 days. Considering the three stations, the net cyst mean number by depth was 2,761; 975 and 258 cysts at 5, 10 and 15 m, respectively. The cysts mean content in the mussel digestive glands for the three stations was 14 cysts g-1 (wet weigth). Since nets and mussels, are widely utilized in fishing and aquaculture activities, could constitute a potential dispersant agents of A. catenella to free areas of this plague declared species in Chile.