Nutrient regimes in a semi-enclosed marginal sea: The Persian Gulf

In this study, the results of hydrochemical measurement aboard the RV Kavoshgar Khalij Fars in the Persian Gulf (PG) in September 2018, May, and November 2019 are discussed. Nitrate, nitrite, ammonium, phosphate, and silicate concentrations, salinity, temperature, dissolved oxygen, and pH in the water column of a 1000-km transect in the PG were studied to determine the present status of nutrient regimes of this region. Nitrate, phosphate, and silicate were more concentrated at the bottom layer and showed a maximum just below the thermocline in summer and autumn. Seasonal distribution of nutrient ratios (N:P, N:Si, Si:P) indicates P limitation in autumn, N limitation in spring, P limitation and poor Si in summer throughout the upper layer. The results of this study do not infer eutrophication in the upper layer of the PG waters in autumn and summer.

本研究对2018年9月、2019年5月及11月期间，在波斯湾（Persian Gulf，以下简称PG）使用"Kavoshgar Khalij Fars"号科考船开展的水化学测量结果进行了讨论。本研究针对PG海域一条1000千米断面的水柱中的硝酸盐、亚硝酸盐、铵盐、磷酸盐、硅酸盐浓度，以及盐度、温度、溶解氧与pH值展开分析，以明确该区域营养盐格局的现状。硝酸盐、磷酸盐与硅酸盐在底层水体中浓度更高，且在夏季与秋季的温跃层下方出现浓度峰值。营养盐比值（N:P、N:Si、Si:P）的季节分布特征显示，该区域上层水体在秋季受磷限制、春季受氮限制，夏季则同时受磷限制且硅酸盐含量偏低。本研究结果并未表明波斯湾上层水体在秋季与夏季存在富营养化现象。