This study reports the first measurements of nitrogen uptake and new data on carbon fixation (¹⁵N/¹³C incorporation) for two size-fractionated phytoplankton (<2 μm and >2 μm), on organic matter, and phytoplankton stocks in Ahe lagoon. Data were collected between November and December 2017, during the hot season with prevailing trade winds. Ammonium and nitrate uptake data (7.58 to 39.81 and 1.80 to 21.43 μmol N m⁻³ h⁻¹, respectively) suggest a rapid turn-over of N-nutrients in the water column and show that primary production was largely sustained by recycled nitrogen providing 68% of the pelagic N demand. These results highlight the spatial heterogeneity of the measured processes linked to the local hydrodynamics, exhibiting higher regenerated production in the more exploited southwestern part of the lagoon and a higher proportion of new production in the north. Intense nutrient recycling appears to promote nanophytoplankton production which is critical for pearl oyster growth.

这项研究报告了Ahe泻湖中两个大小分级的浮游植物（<2μm和> 2μm），有机物和浮游植物种群的氮吸收量的首次测量和碳固定（结合¹⁵ N / ¹³ C）的新数据。数据收集于2017年11月至2017年12月的炎热季节，当时盛行贸易风。铵和硝酸盐吸收数据（7.58至39.81和1.80至21.43μmolN m ^-3  h ^-1分别表明水柱中氮素的快速转换，并表明初级生产在很大程度上由回收的氮维持，提供了中上层氮需求的68％。这些结果突显了与当地流体动力学相关的被测过程的空间异质性，在泻湖西南部开发程度更高的地区显示出更高的再生产量，而北部地区的新产量所占比例更高。强烈的养分循环利用似乎促进了纳米浮游植物的生产，这对珍珠牡蛎的生长至关重要。