Yang Ping, Tan Li-Shan, Huang Jia-Fang, He Qing-Hua, Tong Chuan
School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China.
Key Laboratory of Humid Sub-tropical Eco-geographical Process of Ministry of Education, Fuzhou 350007, China.
Huan Jing Ke Xue. 2018 Jan 8;39(1):300-309. doi: 10.13227/j.hjkx.201705166.
Annual drainage is a typical management activity practiced by operators as a way to export aquaculture effluent, accelerate aerobic decomposition of bottom soils, and avoid eutrophication during the non-culture period after harvest. Drainage activities can cause large changes in hydrology, nutrient cycling, sediment physicochemical properties, and even broad ecosystem functions. In order to understand the effects of drainage on the diurnal variation characteristics and magnitude of greenhouse gas (CH and NO) fluxes from the aquaculture ponds of the estuaries, a 24-hour continuous monitoring was conducted from one undrained pond (UDP) and one drained pond (DP) during early winter in the Minjiang River estuary on the southeast coast of China. Over the entire study period, the fluxes of CH from the UDP and DP ranged from 0.04 to 0.10 mg·(m·h) and 14.04 to 33.72 mg·(m·h), respectively, with means of (0.07±0.01) mg·(m·h) and (24.74±2.33) mg·(m·h). The CH flux was lower during the day and higher at night with a net flux as the sources of the CH. The fluxes of NO from the UDP ranged from -0.027 to 0.011 mg·(m·h), and the average fluxes of (0.002±0.004) mg·(m·h) showed "weak absorption by day and emission at night." The NO fluxes from the DP were emitted all day (ranging from 0.59 to 1.76 mg·(m·h)) with the average fluxes of NO (1.07±0.15) mg·(m·h) indicating higher fluxes at night and lower fluxes during the day. Our research demonstrated that drainage would significantly enhance CH and NO release from the aquaculture ponds. The study also preliminarily confirms that the undrained pond converted to a drained pond considerably alter the diurnal variation characteristics of the CH and NO emissions during early winter. Clearly, future measurements at high frequency over a long time and at different spatial scales would be worth researching from drained aquaculture ponds.
年度排水是养殖者常用的一种管理活动，用于排放养殖废水、加速底泥的好氧分解，并避免收获后的非养殖期出现富营养化。排水活动会导致水文、养分循环、沉积物理化性质甚至广泛的生态系统功能发生巨大变化。为了解排水对河口养殖池塘温室气体（CH和NO）通量日变化特征及通量大小的影响，在中国东南沿海闽江河口初冬期间，对一个未排水池塘（UDP）和一个排水池塘（DP）进行了24小时连续监测。在整个研究期间，UDP和DP的CH通量分别为0.04至0.10毫克·（平方米·小时）和14.04至33.72毫克·（平方米·小时），平均值分别为（0.07±0.01）毫克·（平方米·小时）和（24.74±2.33）毫克·（平方米·小时）。CH通量白天较低，夜间较高，净通量表现为CH的排放源。UDP的NO通量为-0.027至0.011毫克·（平方米·小时），平均通量为（0.002±0.004）毫克·（平方米·小时），呈现出“白天弱吸收、夜间排放”的特征。DP的NO通量全天排放（范围为0.59至1.76毫克·（平方米·小时）），NO平均通量为（1.07±0.15）毫克·（平方米·小时），表明夜间通量较高，白天通量较低。我们的研究表明，排水会显著增强养殖池塘中CH和NO的释放。该研究还初步证实，未排水池塘转变为排水池塘会在初冬期间显著改变CH和NO排放的日变化特征。显然，未来对排水养殖池塘进行长时间高频次和不同空间尺度的测量值得深入研究。
