Krill excretion and its effect on primary production

Marine Ecology Progress Series

Carlos M. Duarte¹  Antonio Tovar-S#xe1nchez¹  Pascal Lehette¹  Santiago Hern#xe1ndez-Le#xf3n¹ 

关键词: Krill;    Ammonium;    Primary production;    Euphausia superba;    Southern Ocean;    Austral summer;    Western Antarctic Peninsula;   

DOI  :  10.3354/meps09746

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

ABSTRACT: During the austral summer, zooplankton excretion along the western Antarctic Peninsula was studied in a contrasting hydrographic regime including coastal and oceanic waters. In coastal waters, ammonium supply by mesozooplankton indicated a low contribution to fuel primary production. In oceanic waters, however, Antarctic krill Euphausia superba contributed a significant percentage to the nitrogen requirements of primary producers. Thus, the ontogenetic migration of adult krill during austral summer should be a key factor regulating the regenerated ammonium for primary production. A significant coupling of ammonium concentration in the water column and in situ krill biomass supported the significant role of krill excretion in the epipelagic realm. Results from short-term experiments with E. superba indicated that ammonium excretion rates were much higher than previously found. Because the use of experimental metabolic rates that are close to field rates would be more appropriate, we suggest to re-assess the ammonium supplied by the epipelagic marine biota. Moreover, the outcomes of experimental krill excretion rates, in situ measurements of ammonium and a review of data on primary production suggest that Antarctic krill sustain a high proportion of the daily phytoplankton production.

【 授权许可】

Unknown