Little wonder - the ocean’s primary productivity


At the base of the ocean’s food chain are algae. Algae feed the krill that feed the whales.

Primary productivity is a measure of how much algae are produced through photosynthesis. Finding out what drives primary productivity is one of the big questions facing the marine scientists on the current New Zealand-Australia Antarctic Ecosystems Voyage to Antarctica.

Marine Ecologist Sarah Bury is leading the continuous collection of water samples aboard NIWA’s deepwater research vessel Tangaroa and the experiments on the algal biomass supporting the krill. It is probably the high krill and fish abundance that attract the humpback whales to the feeding grounds around the Antarctic Balleny Islands.

“From satellite imagery we can see these high concentrations of algal biomass during the four summer months of the year when the humpbacks are feeding there,” Sarah says in this video sent from Tangaroa. An algal bloom in the western margin of the Ross Sea also produced valuable data that we can compare with the productivity around the Balleny islands and the rest of the Southern Ocean, she said.

Twenty-one NIWA and Australian Antarctic Division scientists and the 19-strong crew on Tangaroa are on the homeward leg of the 2015 ecosystems voyage researching the foodwebs of the ocean’s top predators – humpback and blue whales, and Antarctic toothfish.

Tangaroa returns to Wellington Wednesday 11 March to begin the process of collating the research data from the ecosystems voyage.

Read Sarah Bury's full report here

Watch how NIWA’s scientists are studying primary productivity aboard Tangaroa below:

Research subject: Antarctica