象山港滨海电厂温排水对浮游生物的生态影响

应用海洋数值模式ECOM-si耦合一个可用于实时计算的太阳辐射强度和海面热通量计算模块,采用N2P2ZD型生态模型,研究评估了象山港海域的浮游生物量受港内两大滨海电厂(国华电厂和乌沙山电厂)温排水的影响程度。数值模式的模拟结果表明,温排水及其卷载和余氯杀伤效应对海域的浮游生物量有显著影响,一定程度上改变了象山港浮游生物量的季节变化规律和空间分布特征。在春季和初夏等增温季节,温排水的存在可使藻华的发生期提前;夏季高温期,水温超过最佳生长温度,则使浮游植物生物量下降,且可降低赤潮发生的风险;在秋季降温期和冬季低温期,水温低于最佳生长温度,温排水有助于缓解水温的下降,有助于提高该时期海域的初级生产力。除了季节变化上有增有减外,浮游植物和浮游动物量年均水平由于温排水的温升和杀伤效应而降低,碎屑量随之上升,总体上弥补了海域水体总有机体含量的损失,但海域的年均总有机体变化量仍为负值。国华电厂温排水的影响大于乌沙山电厂。无论从温升范围和浮游生物量变化幅度上,国华电厂对铁港的影响都大于黄墩港。

Ecological impact of thermal discharge from coastal power plants on plankton biomass in Xiangshan Bay

A coupled ECOM-si/N2P2ZD model with real-time solar radiation and sea surface heat flux was applied to evaluate the impact of thermal discharge from two coastal power plants (Guohua and Wushashan) on the plankton biomass in Xiangshan Bay. The simulated results show that thermal discharge and its mechanical entanglement and residual chlorine significantly decrease the plankton biomass and change the seasonal and spatial distribution of the biomass. In the warming season, spring and early summer, thermal water makes the occurrence of algal bloom occur earlier than normal. In summer, high water temperature exceeds the optimum growth temperature and leads to a decline of the phytoplankton biomass, and a risk reduction of the red tide. In the cool autumn and cold winter, when the water temperature is lower than the optimum growth temperature, thermal water can increase the primary productivity during this period. In addition to seasonal variation of phytoplankton and zooplankton biomass, annual average biomass of plankton is decreased by the damage of thermal water. The increased amount of detritus decrease the loss of total organism in the sea water, but the changes of annual average total organic matter damaged by thermal water is still negative. The thermal discharge of Guohua power plant impacts greater than Wushashan power plant. Both the range of area with temperature increased and plankton biomass variation, the Guohua power plant impacts the sea area in Tie Port greater than in Huangtun Port.