TY - JOUR
T1 - Living (stained) deep-sea foraminifera off hachinohe (NE Japan, western Pacific)
T2 - Environmental interplay in oxygen-depleted ecosystems
AU - Fontanier, Christophe
AU - Duros, Pauline
AU - Toyofuku, Takashi
AU - Oguri, Kazumasa
AU - Koho, Karoliina Annika
AU - Buscail, Roselyne
AU - Grémare, Antoine
AU - Radakovitch, Olivier
AU - Deflandre, Bruno
AU - De Nooijer, Lennart Jan
AU - Bichon, Sabrina
AU - Goubet, Sarah
AU - Ivanovsky, Anastasia
AU - Chabaud, Gérard
AU - Menniti, Christophe
AU - Reichart, Gert-Jan
AU - Kitazato, Hiroshi
PY - 2014
Y1 - 2014
N2 - Live (Rose-Bengal stained) deep-sea foraminiferal faunas have been studied at five stations between 500-2000-m depth along the NE Japanese margin (western Pacific) to understand how complex environmental conditions (e.g., oxygen depletion, organic matter) control their structure (i.e., diversity, standing stocks, and microhabitats). All stations are characterized by silty sediments with no evidence of recent physical disturbances. The three stations located between 760-1250 m are bathed by dysoxic bottom waters (<45 pmol/L). Although high organic-carbon contents are recorded at all stations (>2.2% DW), only the oxygendepleted sites are characterized by higher concentrations of sugars, lipids, and enzymatically hydrolysable amino acids (EHAA). Sedimentary contents in chlorophyllic pigments decrease with water depth without any major change in their freshness (i.e., [Chl al(Chl a + Pheo a)] ratios). Both Uvigerina akitaensis and Bolivina spissa are restricted to the stations bathed by dysoxic waters, proving their oxygendepletion tolerance. In such conditions, both phytophagous taxa are obviously able to take advantage of labile organic compounds (e.g., lipids and EHAA) contained in phytodetritus. Nonionella stella and Rutherfordoides cornuta survive in oxygen-depleted environments probably via alternative metabolic pathways (e.g., denitrification ability) and a large flexibility in trophic requirements. At stations where oxygen availability is higher (i.e., >70 pmol/L in bottom water) and where bioavailable organic compounds are slightly less abundant, diversity indices remain low, and more competitive species (e.g., Uvigerina curticosta, U. cf. U. graciliformis, Nonionella globosa, Nonionellina labradorica, and Elphidium batialis) are dominant.
AB - Live (Rose-Bengal stained) deep-sea foraminiferal faunas have been studied at five stations between 500-2000-m depth along the NE Japanese margin (western Pacific) to understand how complex environmental conditions (e.g., oxygen depletion, organic matter) control their structure (i.e., diversity, standing stocks, and microhabitats). All stations are characterized by silty sediments with no evidence of recent physical disturbances. The three stations located between 760-1250 m are bathed by dysoxic bottom waters (<45 pmol/L). Although high organic-carbon contents are recorded at all stations (>2.2% DW), only the oxygendepleted sites are characterized by higher concentrations of sugars, lipids, and enzymatically hydrolysable amino acids (EHAA). Sedimentary contents in chlorophyllic pigments decrease with water depth without any major change in their freshness (i.e., [Chl al(Chl a + Pheo a)] ratios). Both Uvigerina akitaensis and Bolivina spissa are restricted to the stations bathed by dysoxic waters, proving their oxygendepletion tolerance. In such conditions, both phytophagous taxa are obviously able to take advantage of labile organic compounds (e.g., lipids and EHAA) contained in phytodetritus. Nonionella stella and Rutherfordoides cornuta survive in oxygen-depleted environments probably via alternative metabolic pathways (e.g., denitrification ability) and a large flexibility in trophic requirements. At stations where oxygen availability is higher (i.e., >70 pmol/L in bottom water) and where bioavailable organic compounds are slightly less abundant, diversity indices remain low, and more competitive species (e.g., Uvigerina curticosta, U. cf. U. graciliformis, Nonionella globosa, Nonionellina labradorica, and Elphidium batialis) are dominant.
UR - http://www.scopus.com/inward/record.url?scp=84905903451&partnerID=8YFLogxK
U2 - 10.2113/gsjfr.44.3.281
DO - 10.2113/gsjfr.44.3.281
M3 - Article
AN - SCOPUS:84905903451
SN - 0096-1191
VL - 44
SP - 281
EP - 299
JO - Journal of Foraminiferal Research
JF - Journal of Foraminiferal Research
IS - 3
ER -