黄河口及其邻近海域营养盐分布特征

NUTRIENT DISTRIBUTION AT THE HUANGHE RIVER ESTUARY

1985年5、8月中法联合调查黄河口海域的营养盐,其样品采用常规的分光光度法测定。营养盐的分布总趋势是河口附近浓度高,外海浓度低,河口与外海浓度之比达数百倍。在河口及其邻近海域营养盐的分布梯度与盐度的分布一致。在河口控制营养盐含量的主要因素是河水和海水的混合过程。在119°30′～50′E,37°25′～38°5′N,PO_4—P,SiO_3—Si出现低值区。在此范围附近恰恰浮游植物的总量比较高。对8月份的02站进行了25h的连续观测,其结果是底层营养盐与盐度有良好的负相关性,而表层的相关性较差 黄河具有很高的氮磷比值,这很可能是农业上用氮肥量增多引起的。

The samples for nutrient measurements were taken in the CF Joint Survey of May and August,1985 and nitrate,phosphate and siJicate were determined by the conventional colorimetry Nitrate,nitrite,phosphate and silicate all tend to be getting higher towords the river.The ratio of nutrient concentration between the estuary and the sea could be up to a factor of several hundred.The gradient distributions of the nutrient concentrations at the estuary and the adjacent sea are consistent with,that of salinity.The linear correlation between the nutrient and the salinity also shows that the main controlling factor of nutrient at the estuary is the mixing processes of fresh water with high nutrient and sea water with low nutrient.An area with very low silicate and phosphate lying in 119°30'-50'E and 37°25'-38.5'N in May of 1985 was associated with a high population of phytoplakton,and suggested that the photosynthesis of phytoplakton was encouraged and the nutrient was consumed very fast.The diurnal observations for nutrient was made at station 2 in August.At the bottom the nutrient was correlated with the salinity quite ideally.On the other hand,at the surface there is poor correlation between nutrient and salinity.The Huanghe River is characterastic of a very high ratio of N/P.The very high ratio of N/P in the Huanghe River is probablly caused by the high errosion of fertilized soil.