Long-Term Copepod Dynamics in the Gulf of Trieste (Northern Adriatic Sea) - Recent Changes and Trends

Abstract

Cluster, time series analyses were applied to 1970-1999 data set of zooplankton collected in the Gulf of Trieste (North Adriatic Sea). Two time periods (1970-1980, 1986-1999) were compared. Copepod associations were identified. Two main groups with two and three subgroups each were identified. Time-series analyses suggest changes in the periodicity of the associations. The long-term annual dynamics of copepod abundance showed an increase in the late 90s compared to the 70s. Small-sized copepods increased in the second period. Changes in the 90s appeared to be related to the climate change in the Northern hemisphere that abruptly arose after 1987.