Santos Janaína Andrade Dos, de Oliveira Karen Figueiredo, da Silva Araújo Isabel Cristina, Avelino Izaura Izadora Ferreira, de Sousa Cajuí Karla Nayara, de Lacerda Luiz Drude, Marins Rozane Valente
Instituto de Ciências do Mar, Universidade Federal do Ceará, Av. Abolição 3207, Meireles, Fortaleza, CE, 60165081, Brazil.
Environ Sci Pollut Res Int. 2016 Dec;23(23):24237-24247. doi: 10.1007/s11356-016-7629-6. Epub 2016 Sep 20.
Monitoring phosphorus (P) concentration in water and sediments in the Castanhão reservoir, under intensive aquaculture, in Northeastern Brazil showed internal process to dominate P cycling following a reduction of reservoir volume due to an extended drought period. A strong negative correlation between soluble reactive phosphorus in surface waters (SRPs) with the reservoir volume results from diminishing dilution capacity; bottom water SRP showed no significant correlation with volume and imply SRP remobilization to surface layers. Total suspended solids (TSS) showed a significant correlation with chlorophyll-a, suggesting change primary productivity following SRP enrichment of surface waters and living cells dominating the TSS. As a result, eutrophication, as established by a trophic state index, was triggered in the reservoir probably enforced by intensive fish farming effluents, whose nutrients accumulated in bottom waters and which became available due to breaking of the thermocline. Since low rainfall periods are typical of the semiarid region and tend to be more frequent and stronger due to climate change, multiple use of reservoirs in NE Brazil should be reevaluated.
对巴西东北部卡斯塔尼奥水库（该水库处于集约化水产养殖之下）水体和沉积物中的磷（P）浓度进行监测发现，由于长期干旱导致水库蓄水量减少，水库内部磷循环过程占据主导地位。表层水体中可溶性活性磷（SRP）与水库蓄水量之间存在很强的负相关关系，这是由于稀释能力减弱所致；底层水体中的SRP与蓄水量无显著相关性，这意味着SRP会重新迁移至表层水体。总悬浮固体（TSS）与叶绿素a呈现显著相关性，这表明表层水体中SRP富集后初级生产力发生了变化，且活细胞在TSS中占主导地位。因此，该水库出现了由营养状态指数确定的富营养化现象，这可能是由集约化养鱼废水加剧的，这些废水的养分积聚在底层水体中，由于温跃层的破坏而释放出来。由于半干旱地区降雨期较短，且受气候变化影响降雨期往往更加频繁和强烈，因此巴西东北部水库的多种用途应重新评估。
