KOSMOS 2020 Peru mesocosm study on ecosystem responses to different light and upwelling intensities: fatty acids in fish larvae

Fatty acids (FA) in fish larvae during the mesocosm experiment in the Peruvian upwelling system near Lima from February-April 2020. Light (ambient = high vs. reduced = low) was manipulated from the beginning (day 0) and upwelling (0 to 60% deep water addition) two weeks into the experiment (day 13). Larvae Peruvian anchovy (Engraulis ringens, 24 days-post-hatch) and chita (Anisotremus scapularis, 44 days-post-hatch) reared in the laboratory were introduced shortly after (day 19). All live fish were caught at the end of the experiment (day 36) by which time most had reached the late larval or early juvenile stage. Whole fish were freeze dried and their FA content and composition determined by gas chromatography. Stomachs had been removed prior to analysis to excluded prey FAs, while all other organs were included. Methodological details in Goldenberg et al. and Thielecke et al. (manuscripts in progress).