南麂列岛养殖功能海域秋季潮致混合特征及其对营养盐浓度的影响

THE CHARACTERISTICS OF TIDE-INDUCED MIXING AND ITS IMPACT ON NUTRIENT CONCENTRATION IN BREADING GROUNDS IN AUTUMN AROUND NANJI ARCHIPELAGO,EAST CHINA SEA

为了推动海水养殖的可持续发展,研究其中水动力过程对生态要素的影响,本文基于实测数据,研究了南麂列岛养殖功能海域秋季的潮致混合特征及其对营养盐浓度的影响。结果显示,该海域雷诺应力呈现出显著落潮占优的特点,而落潮阶段高、低潮附近的转流过程又分别具有正、斜压的特点,进一步导致高潮时雷诺应力峰值被限制于近底层,而低潮时雷诺应力峰值自底至表陆续出现。南麂列岛养殖功能海域营养盐浓度很高,其中NO2-、PO43-与Si O32-浓度受雷诺应力影响显著,而NO3-浓度与盐度相关性明显,主要受水团控制。

Hydrodynamic processes are a vital condition to ecological systems and conducible to local sustainable aquaculture development. Using our in-situ observation data, we studied the characteristics of tide-induced mixing and its impact on nutrients concentrations in autumn in the breeding grounds around Nanji Archipelago, the East China Sea. The results demonstrate that the Reynolds stress in the sea area is ebb-dominant. During ebb tide, there is a conversion between barotropic and baroclinic tides from high to low tide. As a sequence, the high Reynolds stress is limited in the near-bottom layer during high tide while it is present successively from bottom to surface during low tide. The concentrations of nutrients in the breeding grounds around Nanji Archipelago are high. Reynolds stress exerts direct influences on NO2-, PO43-, and Si O32-. However, NO3-is closely related to salinity, and thus controlled by water mass.