Colour clues to ocean productivity

Colour clues to ocean productivity

Ocean colour measured by mean chlorophyll concentrations in phytoplankton, from the SeaWifs satellite ocean colour dataset 1997–2007.

The changing colour of the oceans has been captured by satellites over many years, and NIWA scientists are now analysing the images in a bid to understand ocean productivity.

Ocean colour varies through the seasons, according to the amount of phytoplankton (microscopic algae) at the ocean’s surface. Phytoplankton is a key part of ocean food chains, and the quest is to use colour changes to provide insight into the processes that affect life in the oceans. Over a decade’s worth of satellite data exist, showing seasonal and year-to-year variations in colour. By examining these data, it is hoped to improve models of ocean productivity.

“Ocean colour data are beginning to make it possible to determine patterns in productivity over time and space,” says NIWA’s Dr Sean Kennan. “But there remain many aspects of ocean systems we do not fully understand. Parodoxically, we understand the ‘boring’ parts of the ocean, while the regions of highest productivity seem to be dominated by signals we are still unable to predict. So, we are also looking at physicaldata, such as currents and wind patterns, which we will combine with the colour data to improve our understanding of the total system.”

The research is funded by the Foundations for Research, Science & Technology and the Ministry of Fisheries.