Xu Juchen, Wang Jie, Lin Shen, Hou Liang, Ma Shuaibing, Lv Yabing, Chen Ruiya, He Xugang, Hou Jie
College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China.
College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan 430070, China; Key Laboratory of Aquaculture Facilities Engineering, Ministry of Agriculture and Rural Affairs, Wuhan 430070, China.
Sci Total Environ. 2023 Dec 20;905:167019. doi: 10.1016/j.scitotenv.2023.167019. Epub 2023 Sep 13.
The emergence of aquaculture modes has brought considerable changes to the aquaculture landscape and profoundly influenced environmental processes. However, there is limited research on nutrient cycling in emerging aquaculture modes. This study investigated the characteristics and mechanisms of sediment phosphorus (P) sorption-release in traditional earthen pond culture (TEP) and pond-tank culture mode (PTC), which represents novel aquaculture modes. The results showed that under higher nutrient load, the PTC did not show significant differences in nutrient concentration in water and sediments compared to TEP. Although there are no significant differences in overlying water P concentration between the modes throughout the entire aquaculture period, the trends of its variation over time are different, which significantly affected the P sorption-release characteristics of sediment. Additionally, correlation analysis suggested that calcium-bound P and hot NaOH-extractable organic P may affect the sorption-release characteristics of sediment as active P fractions. The change in redox condition caused by enzyme-mediated organic matter decomposition (such as protein and lipids) is also an important reason for sediment P release. However, the P fractions and organic matter content showed no significant differences between the two modes. Sediment microbial analysis showed that TEP exhibited a significant dominance of inorganic P-solubilizing bacteria, especially Actinobacteria and Bacilli classes. PTC had a higher proportion of organic P-solubilizing bacteria, primarily in the Bacteroidia class. The quantitative results of the key functional gene phoD in organic P decomposition also showed that the abundance in PTC was significantly higher than that in TEP. This suggested that microbial differences may be another reason for differences in P sorption-release behavior. This study revealed the differences in P sorption-release characteristics and mechanisms between the TEP and PTC, which holds positive implications for water quality and pollution management in novel aquaculture modes.
水产养殖模式的出现给水产养殖格局带来了巨大变化，并深刻影响了环境过程。然而，对于新兴水产养殖模式中的养分循环研究有限。本研究调查了传统土池养殖（TEP）和代表新型水产养殖模式的池塘-水槽养殖模式（PTC）中沉积物磷（P）吸附-释放的特征及机制。结果表明，在较高养分负荷下，与TEP相比，PTC在水体和沉积物中的养分浓度上未表现出显著差异。尽管在整个养殖期间，两种模式的上覆水P浓度无显著差异，但其随时间的变化趋势不同，这显著影响了沉积物的P吸附-释放特征。此外，相关性分析表明，钙结合态P和热NaOH可提取有机P作为活性P组分可能影响沉积物的吸附-释放特征。酶介导的有机物（如蛋白质和脂质）分解引起的氧化还原条件变化也是沉积物P释放的重要原因。然而，两种模式之间的P形态和有机质含量无显著差异。沉积物微生物分析表明，TEP中无机P溶解菌占显著优势，尤其是放线菌纲和芽孢杆菌纲。PTC中有机P溶解菌的比例较高，主要为拟杆菌纲。有机P分解中关键功能基因phoD的定量结果也表明，PTC中的丰度显著高于TEP。这表明微生物差异可能是P吸附-释放行为差异的另一个原因。本研究揭示了TEP和PTC之间P吸附-释放特征及机制的差异，这对新型水产养殖模式中的水质和污染管理具有积极意义。
