Distribution, abundance and diversity of modern dinoflagellate cyst assemblages from southern Chile (43-54° S)

The distribution, abundance and diversity of modern dinoflagellate cyst assemblages were investigated in sediments from the inshore seas of southern Chile (43 degrees 08'-54 degrees 55' S) at eight sites from April 2004 to January 2005. A total of 24 cyst types were recorded, of which 12 and five were identified at the species and genus levels, respectively. Dinoflagellate cysts were recorded from all sampling sites, but they differed in total abundance (15-270 cysts ml(-1)) and diversity index (H' 0.88-2.40). Heterotrophic dinoflagellate cysts assigned to heterotrophic species were the most abundant trophic form, with 418 cysts ml(-1), representing 55% of the total cyst abundance. Cluster analysis based on the abundance of dinoflagellate cyst species indicated that sampling sites were segregated into three groups likely to be related to the proportion of autotrophic vs. heterotrophic species cysts and the total abundance of cysts at each site. Distinctive cyst species composition differences among sampling sites may allow inferences about local nutrient and feeding dynamics within the water column.