Nature’s Ocean Fertiliser
(Click to enlarge) Antarctic krill (Euphausia superba) (Credit: Uwe Kils / Wikimedia)
Scientists have discovered that Antarctic krill – a tiny shrimp-like crustacean – plays a key role in fertilising the Southern Ocean with iron, which stimulates the growth of phytoplankton, the microscopic plants at the base of the marine food web. This finding is important for understanding the oceans’ capacity for carbon capture.
(From Phys.org)– Reporting this month in the journal Current Biology, a team of European researchers describe how iron-rich rock particles are dissolved in the acidic guts of krill. The discovery is an important step forward in understanding key processes in one of the most biologically-rich regions of our planet.
The research team found that particles that usually sink to the sea-bed are eaten by krill. Within their acidic guts, iron is freed from these particles and can be released in dissolved form into the ocean either directly by krill, by the microorganisms that decompose krill faecal pellets or by whales, seals and penguins that eat them. Krill also produce iron-binding chemicals (called ligands) that prevent the iron from re-attaching onto particles and therefore release it back into the ocean.
This natural iron fertilisation stimulates the growth of phytoplankton – the tiny plants that bloom in the ice-free surface waters during the Antarctic summer and form the base of the Southern Ocean food web. This process also enhances the Southern Ocean’s capacity for natural storage of carbon dioxide.
Read the full article here: http://phys.org/news/2016-09-nature-ocean-fertiliser.html