Study Shows Whales Essential for Fertilization of Southern Ocean
22.04.2010 - Atmosphere & Space, Water & Oceans, Flora & Fauna, Antarctic
A new study highlights the important role whales play in the fertilization of the Southern Ocean. Iron, a key element that helps algae grow in the oceans, appears to be found in large amounts in the whales’ fecal matter. After feeding on the iron, these algae die and sink deeper into the waters of the ocean, bringing the iron with them. Yet as krill eat the algae, large concentrations of iron build up in their body. Then when krill move back to the surface of the ocean, they get eaten by whales, which then excrete the iron back into the water, starting the cycle all over again.
By studying fecal and tissue samples from four species of baleen whales, scientists found the whales to be responsible for recycling as much as 12% of the current iron content in the surface layer of the Southern Ocean. The iron-recycling role of krill and whales explains how the Southern Ocena ecosystem has been able to support such large populations of predators and prey.
The study suggests that in the future increasing populations of baleen whales and krill could enhance the productivity of the Southern Ocean’s ecosystem and improve its ability to absorb CO2.
