Community structured production of zooplankton in the eastern boundary upwelling system off central/southern Chile (2003–2012). (4th November 2019)

• Record Type: Journal Article
• Authors: Medellín-Mora, Johanna; Atkinson, Angus; Escribano, Rubén
• Editors: Ji, Rubao
• Is Part Of: ICES journal of marine science. Volume 77:Number 1(2020)
• Page Start: 419
• Page End: 435
• Publication Date: 2019-11-04
• Subjects: community structure -- growth rate -- upwelling -- zooplankton biomass -- zooplankton production; Ocean -- Periodicals; Fisheries -- Periodicals; Fishes -- Periodicals; Marine biology -- Bibliography -- Periodicals; 551.4605
• DOI: 10.1093/icesjms/fsz193
• Languages: English
• ISSNs: 1054-3139

Abstract

Abstract: Eastern boundary upwelling systems (EBUS) are highly productive and climatically sensitive ecosystems of the ocean. A critical component sustaining EBUS is the zooplankton secondary production (ZSP) which links primary production (PP) and the higher trophic levels. However, estimating ZSP is a complex task and many questions remain regarding its controlling factors. Here, we used automated analysis to assess taxonomic-structured biomass of zooplankton from a time series (2003–2012) at a fixed station off central-southern Chile. Zooplankton biomasses combined with empirically estimated growth rates, as a function of temperature, Chorophyll-a concentration, and body size, were used to estimate seasonal and interannual changes in ZSP. The annual integrated ZSP yielded a mean of 8.0 g C m −2 y −1, with a minimum in 2009 of 5.7 g C m −2 y −1 and a maximum in 2011 of 13 g C m −2 y −1, and an average annual P/B ratio of 35. The transfer efficiency from PP to ZSP was only 0.8%, indicating a surplus of PP to the system and/or the importance of intermediate microzooplankton levels. Seasonal variation in biomass, ZSP and the P/B ratio were explained mostly by changes in taxonomic structure while interannual variation reflected large-scale climatic changes, such as the Pacific decadal oscillation.