Plankton is the key to ocean life. Phytoplankton convert energy from sunlight into food for tiny animals called zooplankton. These in turn become food for larger animals.
They also provide nearly half of the earth’s atmospheric oxygen and absorb carbon dioxide from the atmosphere. When they die, they sink to the ocean floor where the carbon they took from the atmosphere is stored for thousands of years.
In spring, more light penetrates the surface waters and phytoplankton grow rapidly, reaching a peak in New Zealand around September and October.
Off the east coast of New Zealand, cold rivers of water that have branched off from the Antarctic Circumpolar Current flow north past the South Island and converge with warmer waters flowing south past the North Island. The surface waters of this meeting place are New Zealand’s most biologically productive. This image of the area on October 25, 2009, from the MODIS sensor on NASA’s Aqua satellite shows the basis for that productivity: large blooms of plantlike organisms called phytoplankton.
Phytoplankton use chlorophyll and other pigments to absorb sunlight for photosynthesis, and when they grow in large numbers, they change the way the ocean surface reflects sunlight. Caught up in eddies and currents, the blooms create intricate patterns of blues and greens that spread across thousands of square kilometers of the sea surface.
Photo Credit: NASA/MODIS Rapid Response/Jeff Schmaltz. Caption Credit: Rebecca Lindsey, NASA Earth Observatory.
To learn more about New Zealand’s plankton, visit Te Ara – the encyclopaedia of New Zealand