CCAMLR

This report summarizes the satellite ocean color (chlorophyll) data that are currently available, from missions beginning with the Coastal Zone Color Scanner in the late 1970s through to the SeaWiFS and MODIS sensors that have been providing data for the last ten years. The characteristics of these data and limitations such as cloud cover and high solar zenith angle are discussed with regard to their use in the Southern Ocean. A brief history of algorithms linking ocean color to primary productivity is presented, focusing on the vertically generalized production model (VGPM) and more recent regional, carbon-based approaches. Using monthly climatologies of SeaWiFS chlorophyll, a phenology of phytoplankton blooms is presented for the major provinces surrounding Antarctica. Some of the published information regarding phytoplankton species composition and succession is summarized. Finally, a review of ecosystem and biogeochemical models for the Southern Ocean is presented, with a focus on those models that have been validated using satellite ocean color data.

Krill (Euphausia superba) distribution and abundance data are available from a number of sources: from net surveys (the longest historical series of available date), from acoustic surveys, from fisheries data and from the distribution of krill predators. Each of these forms of data collection has its own biases and limitations and our current understanding of krill distribution and abundance comes from utilising the various forms of data to the maximum extent possible. Time series data are really only available from the South Atlantic where scientific netting programs and annual acoustic surveys have been carried out annually. The South Atlantic is also the area where the fishery has concentrated for the last 20 years. There have been suggestions of changes in the distribution and abundance of Antarctic krill, based mainly on analysis of available scientific net data. There is also evidence of intense inter- and intra-annual variability of krill abundance within regions. These fluctuations in abundance make detection of long-term trends difficult to detect. This review examines the main types of data available for Antarctic krill and will present an indication of the extent and limitations of the available datasets and will present the currently accepted state of knowledge concerning krill distribution, abundance and trends.