Ecologie des foraminifères planctoniques du golfe de Gascogne ...

tel-00480660, version 1 - 4 May 2010
Figure II-2: Sea Surface Temperature (SST) and Chlorophyll-a processed from SeaWiFS images of the Bay
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of Biscay from January 2006 to September 2008. Data represent averages of a 1° square area at Station
WH (44-45°N, 2-3°W).............................................................................................................................. 51
Figure II-3: Temperature difference between the water surface and 100 m water depth (∆T0-100) as a measure
of stratification of the upper water column, with strong stratification at large ∆T0-100 and a well mixed
water column at small ∆T0-100. .................................................................................................................. 52
Figure II-4: Number of stained (cytoplasm bearing, living) planktic foraminifera per cubic meter of sampled
sea water (dark grey: size fraction >150 µm; light grey: size fraction 100-150 µm), in comparison to
chlorophyll-a concentration (mg m -3 , black line) and salinity (PSU, grey line) at Stations WH, A, B, and
D, from March to November..................................................................................................................... 54
Figure II-5: Standing stocks of living planktic foraminifera per cubic meter of seawater at Stations WH, A,
B, and D, from March to November. ........................................................................................................ 55
Figure II-6: Percentage of living PF of the 100-150 µm size fraction at Stations WH, A, B, and D, from
March to November. ................................................................................................................................. 56
Figure II-7: Number of empty (dead) planktic foraminiferal tests per cubic meter of sampled sea water
(black: size fraction >150 µm; grey: size fraction 100-150 µm) at Stations WH, A, B, and D, from
March to November. Temperature (°C) is shown by the black line. ........................................................ 57
Figure II-8: Chlorophyll-a (mg.m -3 ) in the Bay of Biscay, from SeaWiFs images
(http://oceancolor.gsfc.nasa.gov): a) April 2007, before PECH 3 (Table II-1), showing high
phytoplankton production in the central part of the Bay of Biscay. b) November 2007, before PECH 4,
showing enhanced phytoplankton production along the coast of the south-eastern Bay of Biscay, in
comparison to April, and low phytoplankton production in the central Bay of Biscay. Sampling locations
are indicated by black dots (Fig. II-1)....................................................................................................... 59
CHAPITRE III
Partie A
Figure III-1 : Concentration moyenne des foraminifères planctoniques vivants (en spécimen/m 3 ) aux Stations
WH, A, B, et D, de Mars à Novembre. ..................................................................................................... 70
Figure III-2 : Photographie au microscope électronique à balayage de l’espèce G. bulloides provenant du site
internet EMIDAS (http://www.emidas.org).............................................................................................. 72
Figure III-3 : Répartition verticale des densités de G. bulloides aux Stations WH, A, B, et D, de Mars à
Novembre. Profil de chlorophylle-a (courbe noire, mg/m 3 ) ; profil de salinité (courbe grise, PSU). ...... 73
Figure III-4 : Photographie au microscope électronique à balayage de l’espèce G. calida provenant du site
internet EMIDAS (http://www.emidas.org).............................................................................................. 74
Figure III-5 : Répartition verticale des densités de G. calida aux Stations WH, A, B, et D, de Mars à
Novembre. Profil de chlorophylle-a (courbe noire, mg/m 3 ) ; profil de salinité (courbe grise, PSU). ...... 75
Figure III-6: Photographie au microscope électronique à balayage de l’espèce N. pachyderma dextre
provenant du site internet EMIDAS (http://www.emidas.org). ................................................................ 76
Figure III-7: Répartition verticale des densités de N. pachyderma dextre aux Stations WH, A, B, et D, de
Mars à Novembre. Profil de chlorophylle a (courbe noire, mg/m 3 ) ; profil de salinité (courbe grise,
PSU).......................................................................................................................................................... 77