Aix-Marseille Université, Université de Toulon, IRD, CNRS, Mediterranean Institute of Oceanography (MIO), UM 110, 13288 Marseille, France; Institut de Recherche pour le Développement, UMR 241 EIO (Université de la Polynésie française, IRD, ILM, Ifremer), B.P. 6570, 98702 Faa'a, Tahiti, French Polynesia.
Aix-Marseille Université, Université de Toulon, IRD, CNRS, Mediterranean Institute of Oceanography (MIO), UM 110, 13288 Marseille, France.
Mar Pollut Bull. 2021 Jun;167:112352. doi: 10.1016/j.marpolbul.2021.112352. Epub 2021 Apr 16.
This study reports the first measurements of nitrogen uptake and new data on carbon fixation (N/C 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 h, 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.
本研究报告了首次对阿赫泻湖两个浮游植物（<2μm 和 >2μm）、有机物质以及浮游植物存量的氮吸收和碳固定（N/C 结合）的测量数据，测量时间为 2017 年 11 月至 12 月，正值盛行贸易风的炎热季节。氨氮和硝酸盐氮吸收数据（分别为 7.58 至 39.81 和 1.80 至 21.43μmol N m h）表明水柱中的 N 营养物质快速周转，并表明初级生产力主要由再循环氮维持，提供了 68%的浮游 N 需求。这些结果突出了与局部水动力有关的测量过程的空间异质性，在泻湖西南部开发程度较高的地区，再生生产力更高，而北部的新生产力比例更高。强烈的养分再循环似乎促进了对珍珠牡蛎生长至关重要的纳米浮游植物的生产。
