THE INFLUENCE OF PENGUIN EXCREMENT ON PHYTOPLANKTON PRODUCTION DURING SHORT-TERM INCUBATION IN THE ROSS SEA, ANTARCTICA

Abstract

Penguin rookeries in Antarctic coastal areas linked to marine ecosystems since their excretion has bio-available micronutrients and macronutrients for phytoplankton and potentially enhanced phytoplankton productivity and microbiota diversity. Penguin excrement samples were derived from three penguin rookeries (Cape Hallet; Cape, Edmonson point; Ep, and Inexpressible Island; Inex). To investigate the impact of penguin excretion, we conducted excrement-enrichment 13C and 15N dual-labelled phytoplankton incubation experiments with seawater samples collected from near the each penguin rookery in the Ross Sea, Antarctica. Specific carbon and nitrate uptake rates in control were higher than those of treatment during short-term incubation (4 hours), while the opposite was observed for specific ammonium uptake. These responses indicate that nitrate production by natural phytoplankton was regulated and inhibited by high ammonium concentrations from penguin excrement in the Ross Sea.