东北季风期海南岛三亚湾初级生产力分布特征及其影响因素

根据2006年10月和2007年1月的监测资料,对三亚湾在东北季风初始期和盛行期初级生产力的分布特征及其受水体环境的影响因素进行了分析。三亚湾秋、冬季表层潜在初级生产力平均值分别为6.81mgC·m-3·h-1和7.47mgC·m-3·h-1;水柱初级生产力平均值分别为504.96mgC·m-2·d-1和495.33mgC·m-2·d-1。东北季风期间,三亚湾水体垂直混合作用加强,层化现象减弱,水动力过程和营养盐等环境因子是该海湾初级生产力分布特征和季节变化的重要调控因素;其中冬季较高的DIN分布对表层初级生产力有潜在促进作用,而水体扰动增强、真光层深度下降则导致水柱初级生产力低于秋季。三亚河口近岸水域秋、冬季均为营养盐、叶绿素a及初级生产力的高值区,其中表层潜在初级生产力在秋季和冬季分别达到了45.80mgC·m-3·h-1和39.27mgC·m-3·h-1,表明调查期间三亚河营养盐输入对近岸水体浮游植物初级生产过程的显著影响。

Distribution characteristics of primary production and its influence factors in Sanya Bay, Hainan Island during Northeast Monsoon Period

Based on the investigation data from the autumn cruise(August 2006) and winter cruise(January 2007) in Sanya Bay,Hainan Island,the distribution characteristics of primary production(PP) and its environmental impact during the northeast monsoon period were studied.PP in the surface layer averaged 6.81 mgC·m~(-3)·h~(-1) and 7.47 mgC·m~(-3)·h~(-1) during autumn and winter respectively;the mean integrated primary production(IPP) were 504.96 mgC·m~(-2)·h~(-1) and 495.33 mgC·m~(-2)·h~(-1) respectively.The stratification of the waters was weak while the vertical mixing process became intense during the winter monsoon period,the aquatic dynamics and nutrient loadings were key controlling factors of the distribution characteristics and seasonal variation of PP within the period.The higher DIN in winter potentially promoted the primary production in the upper layer,while the increasing turbidity and decreased euphotic layer depth limited the integrated primary production of the bay.The estuary and adjacent area had the highest loadings of macronutrients,Chlorophyll a and PP compared with other waters in both seasons.The PP in the surface layer reached 45.80 mgC·m~(-3)·h~(-1) and 39.27 mgC·m~(-3)·h~(-1) in autumn and winter respectively,suggesting the significant impacts of the Sanya river outflow upon primary production in the nearshore waters of the bay during the investigation period.