广西岩滩水库不同养殖类型区域沉积物磷分布特征分析

Distribution characteristics of phosphorus in sediments from different aquaculture areas in Yantan Reservoir,Guangxi

【目的】评价广西岩滩水库不同养殖类型区域在不同季节的沉积物磷分布特征和释放潜力,为科学发展库区养殖业提供参考依据。【方法】在广西岩滩库区选择非养殖区(T0)、投饵网箱养殖区(T1)、生态网箱养殖区(T2)和围栏养殖区(T3)各3个站位,于2016年3月(春季)、6月(夏季)、9月(秋季)和12月(冬季)分别采集12个站位的表层沉积物,以淡水沉积物磷形态的标准测试法(SMT)测定各种形态磷含量。【结果】不同养殖类型区域表层沉积物磷含量差别明显,整体上表现为T1/T2>T3>T0,T1和T2的沉积物磷含量差异仅表现在投饵季节(夏季和秋季)。不同养殖类型区域沉积物中的铁铝磷(Fe/Al-P)和钙磷(Ca-P)比例差异明显,且二者通常呈反比关系;无机磷(IP)的比例虽然最高,但各养殖区域间差异不显著(P>0.05)。T0只有Fe/Al-P比例存在明显的季节差异,T1各形态磷比例均具有明显的季节差异,T2的Ca-P比例无季节差异,但冬季的Fe/Al-P比例显著高于其他季节(P<0.05),而T3只有Ca-P比例表现出季节差异,其他形态磷均不存在季节差异。各形态磷与总磷(TP)的相关性分析结果表明,IP与TP的相关性最高,相关系数(R2)达0.9632;而有机磷(OP)与TP的相关性最低,对应的相关系数为0.5785。【结论】各种养殖类型均可提高库区沉积物中的磷含量和释放潜力,尤其生态网箱养殖在冬季对磷的释放潜力提升作用最明显。在库区开展水产养殖时即使采用生态养殖模式,也要注意在不同区域实施轮养,避免局部水域因营养盐累积而造成底质恶化。

【Objective】Sediment phosphorus distribution characteristics and potential releasing in different types of aquaculture area in Yantan Reservoir,Guangxi were evaluated to provide reference for scientific development of aquaculture in the reservoir.【Method】In Yantan Reservoir,three stations from each following areas were selected:non-aquaculture area(T0),feeding cage aquaculture area(T1),ecological cage aquaculture area(T2)and fencing aquaculture area(T3).Surface sediment from 12 stations were collected in March(spring),June(summer),September(autumn)and December(winter)of 2016,and standard measurements and testing(SMT)method was used to determinate contents of each form of phosphorus in phosphorus out of fresh water sediment.【Result】Phosphorus content in surface sediment from different aquaculture areas were different,the order of phosphorus contents was T1/T2>T3>T0.The sediment phosphorus content of T1 and T2 only varied in feeding seasons(summer and spring).The proportions of Fe/Al-P and Ca-P in sediment from different aquaculture areas were obviously different,but the two were usually in inverse relation.The proportion of inorganic phosphorus(IP)was high,but the differences among various areas were insignificant(P>0.05).In T0,only proportion of Fe/Al-P had obvious seasonal difference;in T1,all phosphorus forms had obvious seasonal difference;in T2,proportion of Ca-P had no seasonal difference,but proportion of Fe/Al-P in winter was significantly higher than in other seasons(P<0.05);in T3,all forms of phosphorus excepted Ca-P had no seasonal difference.The correlation analysis between various phosphorus forms and total phosphorus(TP)showed that the correlation between IP and TP was the highest with correlation coefficient(R2)being 0.963,and the correlation between organic phosphorus(OP)and TP the lowest with correlation coefficient being 0.578.【Conclusion】All aquaculture types can improve the phosphorus content and release potential in sediment in the reservoir,and ecological cage aquaculture can utmostly unleash the potential of phosphorus in winter.Operating aquaculture in reservoirs should carry out ecological aquaculture and alternate culture in different areas to avoid substrate environment worsening in partial waters due to nutrients accumulation.