Temporal changes in foraminiferal distributions in Miramichi River estuary, New Brunswick

Distribution of foraminifera from surface sediments collected during September 1975 and February 1976 in Miramichi estuary are described and compared to similar data reported previously from the same estuary. Three major assemblage zones presently occupy the estuary: the river, transitional, and open bay assemblage zones. Only two assemblage zones were observed in earlier studies: river and open bay. Sedimentological and geomorphological evidence suggests that circulation patterns in the estuary have changed sufficiently in the past decade to allow the transition assemblage to replace the open bay in large parts of the estuary.A comparison is made between the distributions obtained using a cluster analysis and those obtained using a direct, intuitive approach. The two methods yield almost identical results in this study and the cluster analysis should be a valuable tool when large amounts of data must be interpreted.Seasonal observations were limited; however, no major shifts of faunal zones were detected from September to February. One species, Protelphidium orbiculare, appears to be more common in the warmer months and may require relatively warm temperatures to reproduce.A new complementary classification of estuaries based on circulation detected by foraminiferal assemblages is proposed.