水耕对刺参养殖池塘水质及底质理化因子的影响

Effects of water plowing on water quality and sediment physicochemical factors in sea cucumber (Apostichopus japonicus) culture ponds

中文关键词: 水耕工艺  海参  池塘养殖  水质调控  底质改良  环境因子  沉积物再悬浮

英文关键词: Water plowing operation  Sea cucumber  Pond culture  Water quality control  Sediment improvement  Environmental factors  Sediment resuspension

中文摘要:

      近年来，辽宁、山东地区刺参养殖过程中兴起一种水耕作业方式以调控养殖池塘水质和底质，然而对其水耕工艺和环境改良机理仍不清楚。本实验在辽宁凌海仿刺参 (Apostichopus japonicus) 养殖区开展了为期 48 d 的水耕实验，设置了低频率组（每8天水耕一次）、高频率组（每4天水耕一次）和对照组（不进行水耕），通过短期的连续性跟踪和长期的定期性监测，分析了养殖池塘池水和底质的化学需氧量(COD)、磷酸盐浓度(PO43--P)、氧化还原电位(ORP)、硫化物含量(S22--S)等理化指标的变化情况。研究结果显示，水耕后2d时实验组水体浊度最高达到4.16±0.39 NTU，显著高于对照组（P < 0.05）；第4d时实验组铵态氮和亚硝态氮浓度分别下降了88.9%和75.0%，下降幅度大于对照组。水耕31d时，低频率组和高频率组池塘水体中磷酸盐和亚硝态氮浓度均显著低于对照组，沉积物的有机碳含量也显著低于对照组。从0d到47d，低频率组和高频率组池水中DO分别升高了4.2%、3.8%，低于对照组（37.7％）；COD分别升高了21.4％和21.8％，高于对照组（9.9%）；磷酸盐浓度分别升高了125.0%和100.0%，低于对照组（183.3％）；沉积物的ORP分别提高了67.6和82.3mV，显著高于对照组（31.3 mV）；沉积物的硫化物含量分别降低了6.1%和7.9%，而对照组增长了298.4%；沉积物的弧菌占比分别降低了2.5%和7.1%，而对照组降低了1.8％。研究结果表明，定期水耕作业有利于保持水体磷酸盐处于较低水平，有效抑制沉积物中有机碳和硫化物含量的增加，显著提升了沉积物的ORP，同时能有效的降低沉积物中的弧菌比例，进而起到改良和修复养殖池塘环境的作用。相较于低频率组（每8天水耕一次），高频率组（每4天水耕一次）的环境调控作用更明显。鉴于频繁的水耕作业会导致池水DO略有下降、COD上升和养殖成本增加，具体适宜的水耕频率需根据池水温度、溶解氧浓度和池底污染老化的程度进行调整。该研究结果为制定水耕工艺及其应用推广提供了数据参考，同时也为深入解释其环境改良机理、构建合理的疾病防控工艺、实现刺参的池塘健康养殖奠定了基础。

英文摘要:

      Apostichopus japonicus is one of the most important aquaculture species in China and pond culture is the primarily culture method. In the process of pond aquaculture, with the extension of the aquaculture period, organic fertilizer, residual bait, phytoplankton debris and excrement of aquaculture species in the water will be deposited in a large amount at the bottom of the pond, which will not only lead to the decline of water quality, but also cause a large number of toxic substances in the sediment, which will seriously affect the output of sea cucumber. In recent years, a water plowing operation mode has emerged during sea cucumber culture in Liaoning and Shandong Provinces, to control the water quality and pond sediment. However, the water plowing technology and environmental improvement mechanism are still unclear. A 48-days water plowing experiment was carried out in the sea cucumber culture area in Liaoning Province. The low-frequency group (water plowing once every 8 days), high-frequency group (water plowing once every 4 days) and control group (no water plowing) were set up. Through short-term continuous tracking and long-term regular monitoring, the changes of physicochemical factors such as chemical oxygen demand, phosphate concentration, redox potential and sulfide content in the water and sediment of the culture pond were analyzed. The results showed that the turbidity of water in the experimental groups were 4.16 ± 0.39 NTU, which was significantly higher than that in the control group at two days after water plowing operation; On the fourth day, the concentration of ammonium nitrogen and nitrite nitrogen in the experimental groups decreased by 88.9% and 75.0%, respectively, which was greater than that in the control group. After 31 days of water plowing, the concentrations of phosphate and nitrite nitrogen in the pond water of the low-frequency group and the high-frequency group were significantly lower than those of the control group, and the content of organic carbon in the sediment was also significantly lower than that of the control group (P < 0.05). After 47 days of water plowing, DO in pond water of low frequency group and high frequency group increased by 4.2% and 3.8%, respectively, but was lower than of the control group (37.7%). Conversely, COD increased by 21.4% and 21.8%, respectively, exceeding the control group (9.9%). The phosphate concentrations increased by 125.0% and 100.0%, respectively, yet were still lower than the control group (183.3%). ORP of sediments increased by 67.6 mv and 82.3 mV respectively, which were significantly higher than that of the control group (31.3 mV); The sulfide content in sediments decreased by 6.1% and 7.9%, respectively, while that in the control group increased by 298.4%; The proportion of Vibrio in sediments decreased by 2.5% and 7.1%, respectively, while that in the control group decreased by 1.8%. The results show that regular water plowing operation can conducive to keeping the water inorganic phosphorus at a low level, effectively inhibit the increase of organic carbon and sulfide content in sediments, significantly improve the ORP of sediments, and effectively reduce the proportion of Vibrio in sediments, thus the water plowing operation could improve and repair the aquaculture pond environment. Compared to the low-frequency group (water plowing once every 8 days), the high-frequency group (water plowing once every 4 days) exhibited more pronounced environmental regulatory effects. However, given that frequent aquatic tillage may lead to a slight decrease in DO, an increase in COD, and higher aquaculture costs, the optimal tillage frequency should be adjusted based on specific conditions, including pond water temperature, dissolved oxygen concentration, and the degree of sediment pollution and aging. The research results provide data reference for the development of water plowing technology and its application and promotion, and also lay the foundation for the in-depth explanation of its environmental improvement mechanism, the construction of disease prevention and control technology, and the realization of healthy culture of sea cucumber A. japonicus.