Influence of Subantartic and Subtropical Oceanic Water on the Zooplankton and Hydrology of Waters Adjacent to the Derwent River Estuary, South-eastern Tasmania

Abstract

The oceanic influence on coastal waters adjacent to the mouth of the Derwent River estuary was examined over a season using zooplankton samples. There is strong evidence to indicate the influence of oceanic water in Storm Bay and the mouth of the Derwent River estuary. The occurrence of indicator species suggests that the area is invaded by subantarctic water from August to January and by subtropical water most strongly in February and March. The seasonal abundance and distribu- tion of the major copepods (12 species), chaetognaths (three species), one euphausiid and one tunicate species are described in detail and the importance of these species as indicators of intrusion and mixing of water masses in this region is evaluated.