Diatom fatty acid biomarkers indicate growth rates in Antarctic krill

• Main Authors: Pond, D.W., Atkinson, A., Shreeve, R.S., Tarling, G.A., Ward, P.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: AMER SOC LIMNOLOGY OCEANOGRAPHY 2005
• Subjects: Marine Sciences; Zoology; Biology and Microbiology; Ecology and Environment; Antarctic; Austral; Antarc*; Antarctic Krill; Euphausia superba
• Online Access: http://nora.nerc.ac.uk/id/eprint/10192/

We investigated the relationship between nutritional condition (levels of specific fatty acids) and growth increment (percentage growth per intermoult period, percentage IMP-1) for Antarctic krill (Euphausia superba) collected from the vicinity of South Georgia in the austral summer 2002. There were correlations between percentage IMP-1 and the concentration (gram: gram dry weight) of the diatom biomarker fatty acids, 16: 4(n-1) and 20: 5(n-3) in tissues of individual krill, suggesting that the abundance of diatoms in the environment of the krill in the intermoult period prior to moulting was a key determinant of change in body length, a proxy for growth. This substantiates the view that diatoms are crucial for supporting high growth rates of krill, either as a direct food source or, indirectly, by enhancing production of microzooplankton and mesozooplankton based food webs.