Influence of freshwater and terrigenous material on nutrients, bacteria and phytoplankton in a high island lagoon: Mayotte, Comoro Archipelago, Indian Ocean

摘要: Freshwater and terrigenous suspended material inputs were studied in Longoni Bay, an area of the lagoon Mayotte (Comoro, Indian Ocean) that is unaffected by influence most populated island. The on waters was limited to coastal zone resulted increase inorganic nitrogen silica. response bacteria their cell volume; phytoplankton cyanobacteria numbers chlorophyll a related ammonia. Ammonification apparently enhanced freshwater whereas nitrification seawater. high nitrate silicate content reef explained neither river or rainfall nor enrichments ocean waters. hypothesis participation marine groundwater discharges this enrichment examined found be supported range concentrations because did not concern ammonia nitrite but only occurred during wet period when aquifer fed abundant rainfall. characteristics biomass lower level heterotrophic activity concentration. changes observed confirmed linked material, possibly discharge groundwater, yielded number increased biomass, despite drop large numbers, strong part small cyanobacteria. This enough place Lagoon among richest island lagoons, with regard a.