Grenz C. auteur aut IRD Rodier Martine auteur aut IRD Seceh C. auteur aut IRD Varillon David auteur aut IRD Haumani G. auteur aut IRD Pinazo C. auteur aut IRD text journalArticle eng text/pdf born digital access Benthic exchanges of oxygen and nutrient at the sediment-water interface were investigated under light and dark conditions at 5 selected sites in a sub-tropical atoll. Mean oxygen fluxes were - 1316.5 +/- 242.0 mu mol m(-2) h(-1) and mean effluxes of oxygen under light conditions were 2231.7 +/- 626.4 mu mol m(-2) h(-1), presumably due to microphytobenthos present at the sediment-water interface. The consequences of this high related productivity was a systematic consumption of nutrients (DIN, PO4 and Si(OH)(4)) during almost all light incubations, contrasting with the effluxes of nutrients during dark incubations. Our results suggest that the sediments were net autotmphic and the oxygen balance in favor of microbenthic production when compared to community demand. Diurnal rates of gross benthic primary productivity were high (3423 +/- 1192 mu mol m(-2) h(-1)) which emphasize the role of microphytobenthos in maintaining the oxygen reservoir in tropical lagoons. specialized Benthic nutrient fluxes Sediment respiration Phytobenthic production Atoll lagoon Pearl farming French Polynesia POLYNESIE FRANCAISE TUAMOTU GAMBIER 040 032 034 173 A 112963 [8 ] 2021 0025-326X https://www.documentation.ird.fr/hor/fdi:010083236 10.1016/j.marpolbul.2021.112963 0025-326X [F B010083236] https://www.documentation.ird.fr/hor/fdi:010083236 https://www.documentation.ird.fr/intranet/publi/2021-11/010083236.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2021-11-10 2025-02-24 fdi:010083236 fre