The role of arctic zooplankton in biogeochemical c

Authors: M Alcaraz R Almeda A Calbet E Saiz C M Duarte S Lasternas S Agustí R Santiago J Movilla A Alonso

Publish Date: 2010/03/31

Volume: 33, Issue: 12, Pages: 1719-1731

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Abstract

The study of the structural and functional properties of key components of polar marine ecosystems has received increased attention in order to better understand the ecological consequences of future sea temperature rise and seasonal ice retraction Owing to this purpose during the ATOSArctic cruise held in July 2007 in the framework of the 2007–2008 International Polar Year we studied the respiratory carbon demand of mesozooplankton as well as their contribution to the regeneration of inorganic nitrogen and phosphorus NH4N and PO4P via excretion The studied area comprised several stations along a latitudinal gradient in the East Greenland current plus a network of stations NW of the Svalbard islands The specific respiratory carbon losses and phosphorus PO4P excretion rates were similar or slightly higher than some reports for Arctic mesozooplankton but the nitrogen NH4N excretion rates were higher by a factor of 3 when compared with previous data sets The mesozooplankton respiratory losses were equivalent to 23 of primary production and at turn zooplankton contributed by excretion to more than 50 of the N and P required by phytoplankton Although CN CP and NP metabolic atomic quotients almost coincided with the average Redfield’s stoichiometric ratios the low CN values when compared to previous reports suggested a predominance of proteinrelated metabolic substrates The potential consequences of changes observed in the CN NP and CP metabolic ratios of mesozooplankton for Arctic marine ecosystems are discussedThe authors are indebted to all the participants to the ATOSArctic cruise and particularly to the crew of the BIO “Hespérides” and the technical staff of the UTM CSIC P Jimenez and E Velasco contributed to the analysis of zooplankton biomass and X Irigoien and JA Fernandes gave valuable suggestions for the use of ZooImage® software This research was supported by the Spanish grants POL20060550/CTM to C D CTM200612344C0201 to M A 2005SGR00219 from the Generalitat de Catalunya to M A A C and E S and a PhD fellowship BES20057491 to RA

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