Zooplankton Biomass Depletion Event Reveals the Importance of Small Pelagic Fish Top-Down Control in the Western Mediterranean Coastal Waters

The influence of hydrochemistry and trophic conditions on the coastal zooplankton community’s biomass and metabolic activities was investigated along the Spanish Mediterranean coastal waters, from Algeciras Bay to Barcelona, from autumn 2011 to autumn 2012. Two hydrographic regions were differentiat...

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Bibliographic Details
Authors: Yebra, Lidia, Espejo, Estefanía, Putzeys, Sébastien, Giráldez, Ana, Gómez-Jakobsen, Francisco José, León, Pablo, Salles, Soluna, Torres, Pedro, Mercado, Jesús M.
Format: article
Status:Published version
Publication Date:2020
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/346172
Online Access:http://hdl.handle.net/10261/346172
https://api.elsevier.com/content/abstract/scopus_id/85099130242
Access Level:Open access
Keyword:AARS activity
Alboran Sea
ETS activity
small pelagic fish landing data
western Mediterranean Sea
zooplankton biomass
zooplankton metabolism
zooplankton production
Description
Summary:The influence of hydrochemistry and trophic conditions on the coastal zooplankton community’s biomass and metabolic activities was investigated along the Spanish Mediterranean coastal waters, from Algeciras Bay to Barcelona, from autumn 2011 to autumn 2012. Two hydrographic regions were differentiated: NW Alboran (ALB) and W Mediterranean (MED). Zooplankton metabolism was assessed from measurements of the electron transport system (ETS) and aminoacyl-tRNA synthetases (AARS) activities, as proxies for potential respiration and somatic growth, respectively. Zooplankton showed three to fivefold higher biomass in ALB than in MED during autumn 2011 and spring 2012. However, in autumn 2012, a drastic decrease in biomass standing stock was observed in ALB, with no significant differences between the two regions. This biomass depletion event was not associated with environmental variables, food availability or zooplankton metabolic rates, but coincided with a twofold peak of Sardina pilchardus landings in ALB. A reduced standing stock coupled with high zooplankton growth rates suggests mortality by predation as the main cause for the low zooplankton biomass typically observed in MED, and in ALB during autumn 2012.