Grenz C., Rodier Martine, Seceh C., Varillon David, Haumani G., Pinazo C. (2021). Benthic nutrients and oxygen fluxes at the water sediment interface in a pearl farming atoll (Ahe, Tuamotu, French Polynesia). Marine Pollution Bulletin, 173 (A), 112963 [8 p.]. ISSN 0025-326X.
Titre du document
Benthic nutrients and oxygen fluxes at the water sediment interface in a pearl farming atoll (Ahe, Tuamotu, French Polynesia)
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.
