Ecologie des foraminifères planctoniques du golfe de Gascogne ...

tel-00480660, version 1 - 4 May 2010
Indicator Species
Upwelling indicator (proxy) in using the relative abundance of bulloides with ruber (Bé and Tolderlund, 1971; Bé and Hutson, 1977) upwelling (Thiede, 1975; Peeters,
2000 ; Ivanova 2000). Cold waters (Boltovskoy et al 2000). Surface-water masses enriched in nutrients (Mücke and Oberhansli, 1999). Best indicator for the depth of
the DCM (Wilke et al., 2008) Opportunistic, high production regime (Kucera, 2007)
G. bulloides
Well indicator of isotope oxygene. Oligotrophic waters (Schmucker and Schiebel 2002) G. siphonifera
Oligotrophic waters (Schmucker and Schiebel 2002) G. calida
Some high latitude species (e.g. T. quinqueloba) may indicate areas of intermediate or deep water formation (Hilbrecht, 1996) ; are known to represent cold waters at
higher latitudes (Bé and Tolderlund, 1971; Schiebel et al., 2000); Assemblages in upwelling area : N. pachy and quinqueloba (Giraudeau, 1993). Cold waters
(Boltovskoy et al 2000). Survives at lower food concentrations than N. pachyderma dextral and G. bulloides (because of symbionts) (Ortiz et al., 1995)
Diatoms : bloom au printemps -> Glutinata marque ce 1er bloom du printemps car coincide avec deep mixed layer (Schiebel et al 2000) phytoplankton (Hemleben et
al; 1989)
Cold waters, oxygenates and rich in nutrients, cold intrusion (Boltovskoy et al 2000); T. quinqueloba and G. uvula are small planktic foraminifera often related to
upwelling or oceanic fronts (Parker, 1971; Hemleben et al 1989; Kroon et al., 1991)
T. quinqueloba
G. glutinata
G. uvula
Well isotopic indicator, oligotrophic zone (Schiebel et al 2004; Venec Peyré et al 1995) G. ruber (white)
G. trilobus trilobus
G. trilobus sacculifer
Winter species (Loncaric et al 2007; Healy-Williams et al., 1989); Winter and early spring species (Schiebel et al., 1995) G. hirsuta
Offshore oligotrophic environment (Giraudeau, 1993); Strong link between G. inflata and frontal regions (?), increase % and sp/m3 in frontal regions (Rohling et al
1995); G. inflata in Bengal-Angola Frontal zone; and could be link with nitate and phosphate concentration and deep mixed layer (Ufkes et al 1998; pujol ret al 1995;
ottens, 1992); appears to have been directly affected by Azores front (but no significant (low number)) (Schiebel et al 2002). Prefers homothermal water masses and
mesotrophic frontal systems (Pujol and Vergnaud Grazzini, 1989, Ottens, 1992; Ulfkes et al 1998). Prefers homothermal water masses created during winter
(Coulbourn et al., 1980; Ganssen and Sarnthein, 1982)
Would record intermediate environnemental conditions ; appears to have been directly affected by Azores front (but no significant (low number)), could be used
occurrence of G. scitula to map the position of the recent AF (substitute to inflata) (Schiebel et al 2002)
Cold water and high latitude form (Parker, 1971); Prefers a deep thermocline ( dextral) (Lohmann and Schweitzer, 1990). Reconstruction of paleoceanographic
conditions (Kennett, 1968; Lohmann and Malmgren, 1983). Offshore oligotrophic environment (Giraudeau, 1993). Apparently, left-coiled G. truncatulinoides inhabits
nutrient-depleted centers of the subtropical gyres, whereas right-coiled G. truncatulinoides prefers more productive environments such as the margins of the
subtropical gyres (Renaud and Schmidt, 2003).
Productive environment like margin of eydies subtropical or upwelling zone (de Vargas et al 2001) ; Reconstruction of paleoceanographic conditions (Kennett, 1968;
Lohmann and Malmgren, 1983). Offshore oligotrophic environment (Giraudeau, 1993); right-coiled G. truncatulinoides prefers more productive environments such as
the margins of the subtropical gyres than left-coiled (Renaud and Schmidt, 2003)
This species has also associated with upwelling areas (Gireaudeau, 1993; Sautter and Thunell, 1991; Ufkes and Zachariasse, 1993) and occuring in maximum
concentrations during periods of high fertility (diatoms blooms) (Salgueiro et al 2008); high food levels and low temperatures , less stratified waters with a high primary
production (Reynolds and Thunell, 1985; Pujol and Vergnaud-Grazzini, 1989; Ottens 1992).
G.inflata
G. scitula
G. truncatulinoides senestre
G. truncatulinoides dextre
N. pachyderma dextre
Province limit left-right form : isotherm of 7,2 in April (Ericson, 1959); Cold waters, Polar and subpolar region (Bé, 1977; Hemleben et al., 1989) pachyderma senestre
N. dutertrei, measure intensity of an upwelling and productivity: differences isotopic C13 of both sp (bull et duter) thermocline and surface dweller : record the change
of thermocline (Peeters, 2000); appear in the upwelling area (Thunell and Sautter, 1992); prefers a thermally stratified water with a pronounced chloro maximum
(Thunell and Sautter, 1992) tropical and subtropical upwelling area (Mücke and Oberhansli, 1999)
P-D intergrade-dutertrei
Well isotopic indicator. The association with an alguae could represent a productivity"hot spot" in oligotrophic waters (Spero and Parker, 1985) O. universa
One of the less productive in sediment and very rare in sediments (Parker et Berger, 1971) H. pelagica