Seasonal variations in upwelling and in the grazing impact of copepods on phytoplankton off A Coruna (Galicia, NW Spain)

被引:18
作者
Bode, A [1 ]
Alvarez-Ossorio, MT [1 ]
Barquero, S [1 ]
Lorenzo, J [1 ]
Louro, A [1 ]
Varela, M [1 ]
机构
[1] Inst Espanol Oceanog, Ctr Costero A Coruna, La Coruna 15080, Spain
关键词
zooplankton; grazing; copepods; upwelling; phytoplankton; NW Spain;
D O I
10.1016/S0022-0981(03)00370-8
中图分类号
Q14 [生态学(生物生态学)];
学科分类号
071012 ; 0713 ;
摘要
The impact of grazing by copepods on phytoplankton was studied during a seasonal cycle on the Galician shelf off A Coruna (NW Spain). Grazing was estimated by measuring the chlorophyll gut content and the evacuation rates of copepods from three mesh-size classes: 200-500 (small), 500-1000 (medium), and 1000-2000 mum (large). Between February 1996 and June 1997, monthly measurements of water temperature, chlorophyll concentration, primary production rates, and copepod abundance, chlorophyll gut content, and evacuation rates were taken at an 80-m-deep, fixed shelf station. Additionally, the same measurements were collected daily during two bloom events in March and in July 1996. Small copepods were the most abundant through the seasonal cycle. The highest grazing impact, however, was due to the medium and large size classes. Grazing by small copepods. exceeded grazing by medium and large copepods only during phytoplankton spring blooms. The impact of copepod grazing (considering all size fractions) was generally low. On average, 2% of the phytoplankton biomass and 6% of the primary production were removed daily by the copepod community. Maximum grazing impact values (9% of the phytoplankton biomass and 39% of the primary production) were found in mid-summer. These results suggest that most of the phytoplankton biomass would escape direct copepod grazing in this upwelling area. (C) 2003 Elsevier B.V. All rights reserved.
引用
收藏
页码:85 / 105
页数:21
相关论文
共 49 条
[1]  
[Anonymous], 1994, PROTOCOLS JOINT GLOB
[2]  
Bamstedt U., 2000, P297
[3]   Ingestion rates of phytoplankton by copepod size fractions on a bloom associated with an off-shelf front off NW Spain [J].
Barquero, S ;
Cabal, JA ;
Anadon, R ;
Fernandez, E ;
Varela, M ;
Bode, A .
JOURNAL OF PLANKTON RESEARCH, 1998, 20 (05) :957-972
[4]   The contribution of microzooplankton to the diet of mesozooplankton in an upwelling filament off the north west coast of Spain [J].
Batten, SD ;
Fileman, ES ;
Halvorsen, E .
PROGRESS IN OCEANOGRAPHY, 2001, 51 (2-4) :385-398
[5]   Mesoscale estimations of primary production in shelf waters: a case study in the Golfo Artabro (NW Spain) [J].
Bode, A ;
Varela, M .
JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY, 1998, 229 (01) :111-131
[6]   Estimations of mesozooplankton biomass in a coastal upwelling area off NW Spain [J].
Bode, A ;
Alvarez-Ossorio, MT ;
Gonzalez, N .
JOURNAL OF PLANKTON RESEARCH, 1998, 20 (05) :1005-1014
[7]   Preliminary studies on the export of organic matter during phytoplankton blooms off La Coruna (north-western Spain) [J].
Bode, A ;
Varela, M ;
Barquero, S ;
Alvarez-Ossorio, T ;
Gonzalez, N .
JOURNAL OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM, 1998, 78 (01) :1-15
[8]  
Bode Antonio, 1994, Scientia Marina, V58, P131
[9]  
Bode Antonio, 1994, Scientia Marina, V58, P221
[10]  
BRAUN J G, 1990, Boletin Instituto Espanol de Oceanografia, V6, P81