Dinoflagellate cyst assemblages from Effingham Inlet, Vancouver Island, British Columbia, Canada

A palynological study of surface samples from Effingham Inlet, southwestern Vancouver Island, British Columbia, was carried out to assess environmental and oceanographic controls on the distribution of dinoflagellate cyst species. Generally dinoflagellate cyst assemblages from all samples are dominated by Operculodinium centrocarpum sensu Wall and Dale, 1966, Spiniferites spp. and round brown (protoperidinioid) cysts. The differences among the assemblages are mainly in relative and absolute abundance of various taxa, presence and absence of various protoperidinioid taxa, species diversity (Shannon Diversity Index), dinoflagellate cyst concentration in the samples, and ratio of terrestrial to marine palynomorphs. Dinoflagellate cyst assemblages in the two sub-basins of this inlet are quite distinct, with the inner basin characterized by lower diversity and the outer basin being characterized by higher diversity due to the occurrence of several protoperidiniacean species. Primary productivity in this inlet is enhanced by periodic incursion of nutrient-rich surface water from the Pacific Ocean which is related to coastal upwelling. Primary productivity is higher in the outer basin than the inner basin.