Plankton – the foundation of marine food webs
Graham Hosie (Australian Antarctic Division, Dept of Sustainability, Environment, Water, Population and Commuities)
Plankton are the foundation of marine food webs. Phytoplankton form the pastures of the sea and grazing zooplankton convert that production into food for higher trophic levels. Plankton are also important to humans in relation to ecosystem service, e.g. supporting food for humans, gaseous exchange of oxygen and carbon dioxide, and the production of unique biochemicals. Our concern is that substantial changes in plankton may have flow on effects to the rest of ecosystem, including humans. Plankton are very sensitive to changes in their environment which can affect their distribution, abundance and composition. Plankton monitoring programmes have identified long-term and sudden ecosystem changes in various ocean systems. Plankton have also been used to identify and map marine biogeographic zones and changes in the geography of the zones. Australia has developed a number of surveys to map and monitor coastal and ocean plankton. This includes the Southern Ocean Continuous Plankton Recorder Survey which has been mapping plankton patterns in relation to the various oceanographic fronts of the Southern Ocean and contributing to the bioregionalisation of the region. It also includes the recently established Australian AusCPR survey studying plankton in coastal systems, notably the East Australian Current, and monitoring plankton at various National Reference Stations. Plankton have proved useful in identifying and monitoring spatial and temporal boundaries. This symposium invites presentations on spatial and temporal dynamics of plankton across biogeographic zones, and the links with other environmental variables.