Journal of the Marine Biological Association of the UK

Table of Contents - 2004 - Volume 84, Issue 03  


Research Article

The spatial distribution of plankton communities in a Slope Water anticyclonic Oceanic eDDY (SWODDY) in the southern Bay of Biscay

Emilio  Fernández a1c1, Florentina  Álvarez a2, Ricardo  Anadón a2, Susana  Barquero a3p1, Antonio  Bode a3, Ana  García a4, Carlos  García-Soto a4, Julio  Gil a4, Nicolás  González a3, Arantza  Iriarte a5, Beatriz  Mouriño a1, Francisco  Rodríguez a6p2, Ricardo  Sánchez a4p3, Eva  Teira a1, Silvia  Torres a1, Luis  Valdés a7, Manuel  Varela a3, Ramiro  Varela a1 and Manuel  Zapata a1a6
a1 Facultad de Ciencias del Mar, Universidad de Vigo, E-36200, Vigo, Spain
a2 Departamento de Biología de Organismos y Sistemas, Universidad de Oviedo, E-33071, Oviedo, Spain
a3 Instituto Español de Oceanografía, Centro Costero de A Coruña, E-15001, A Coruña, Spain
a4 Instituto Español de Oceanografía, Centro Costero de Santander, E-39004, Santander, Spain
a5 Departamento de Biología Vegetal y Ecología, Universidad del Pais Vasco, E-48080, Bilbao, Spain
a6 Centro de Investigacións Mariñas, Xunta de Galicia, E-36620, Vilanova de Arousa, Spain
a7 Instituto Español de Oceanografía, Centro Costero de Gijón, E-33212, Gijón, Spain

Article author query
fernandez e   [PubMed][Google Scholar] 
alvarez f   [PubMed][Google Scholar] 
anadon r   [PubMed][Google Scholar] 
barquero s   [PubMed][Google Scholar] 
bode a   [PubMed][Google Scholar] 
garcia a   [PubMed][Google Scholar] 
garcia-soto c   [PubMed][Google Scholar] 
gil j   [PubMed][Google Scholar] 
gonzalez n   [PubMed][Google Scholar] 
iriarte a   [PubMed][Google Scholar] 
mourino b   [PubMed][Google Scholar] 
rodriguez f   [PubMed][Google Scholar] 
sanchez r   [PubMed][Google Scholar] 
teira e   [PubMed][Google Scholar] 
torres s   [PubMed][Google Scholar] 
valdes l   [PubMed][Google Scholar] 
varela m   [PubMed][Google Scholar] 
varela r   [PubMed][Google Scholar] 
zapata m   [PubMed][Google Scholar] 

Abstract

Slope Water anticyclonic Oceanic eDDIES (SWODDIES) are typical mesoscale features of open-ocean waters of the southern Bay of Biscay which usually develop in winter by shedding from the seasonal poleward current flowing along the northern Spanish slope. These eddies have been intensively studied from the physical perspective. However, their effect on the distribution of biological properties and on the functioning of the pelagic ecosystem has not been assessed so far. To this aim, a sea-truth, multidisciplinary and comprehensive study of a SWODDY was carried out in summer 1998. The eddy, radius of [approximate]50 km, was initially centred at 45·5°N 6·0°W, being characterized by a relatively homogeneous core of water in the centre of the eddy extending from 80 to about 200 dbar. In the central region of the core, temperature (12·55–12·75°C) and salinity ([approximate]35·70) values were higher than outside the eddy. The optical properties of the eddy also differed from those of the surrounding waters. A distinct biological signature was found associated with the eddy. Depth-integrated chlorophyll-a concentrations were 25% higher at the eddy centre where upward doming of the seasonal pycnocline (up to 30 dbar) occurred. Enhanced phytoplankton biomass was related to a higher contribution of >10 μm cells, mainly represented by diatoms and chrysophyceans. Phytoplankton and mesozooplankton species composition in and outside the eddy differed significantly reflecting the coastal origin of the water parcel trapped by the eddy. The sharp modification of the planktonic community composition, biomass and associated size-structure caused by slope water oceanic eddies are likely to exert a significant effect upon the upper trophic levels of the pelagic ecosystem of the southern Bay of Biscay.

(Received September 5 2003)
(Accepted April 15 2004)


Correspondence:
c1 e-mail: esuarez@uvigo.es
p1 Plymouth Marine Laboratory, Prospect Place, West Hoe, Plymouth, PL1 3DH, UK
p2 Station Biologique, UMR 7127 CNRS/INSU/UPMC, BP 74, 29682 Roscoff, France
p3 CIACOMAR–Universidade do Algarve, Avenida 16 de Junho s/n, 8700-311, Olhão, Portugal

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