Zooplankton of Moreton Bay

Abstract

Moreton Bay is a subtropical bay in south east Queensland that supports important populations of seabirds, marine mammals, reptiles and fish. Zooplankton, being small, are often overlooked, but are important nutrient cyclers and a critical link between primary producers and higher trophic levels. Here we synthesise available information on the zooplankton of Moreton Bay, from copepods to jellyfish, and describe their important roles in marine food webs. Zooplankton research in the Bay has a long history, focusing primarily on taxonomy, key taxa, seasonality, demersal zooplankton and jellyfish. Copepods dominate the fauna in the Bay, accounting for 74% of the permanent members. The temporary members of the zooplankton comprise early life stages of littoral species of molluscs, decapods, barnacles, annelids and fish. The dominant large zooplankton species is the jellyfish Catostylus mosaicus that swarms periodically, and its large biomass at times contributes significantly to nutrient cycling. Compared with immediately offshore, zooplankton in the Bay are more abundant but generally smaller in size and contain more meroplankton. In addition, the copepod community is more similar to communities of other tropical shallow coastal regions than zooplankton immediately offshore. Water quality models for the Bay have provided new insights into the variation of zooplankton in time and space that are difficult to investigate using standard sampling approaches. We conclude by highlighting key research gaps that need to be filled, namely the impact of flood events on zooplankton; the use of zooplankton as indicators of water quality to complement solely physico-chemical variables; harnessing historical data to assess the degree to which zooplankton communities have changed over recent decades; and the validation of the zooplankton components in water quality models.