虾塘养殖对红树林沉积物和间隙水理化性质的影响

红树林湿地在近海水体营养控制和营养盐循环过程中扮演着重要的角色。沉积物、水体和植被相互作用共同维持其生态功能的运转，了解虾塘养殖对林下沉积物和间隙水养分特征影响对评价红树林生态功能具有重要指导意义。本研究以受虾塘养殖废水排放不同影响程度的红树林（无排放区、直排区、修复区）为研究样地，通过不同生境下沉积物与间隙水养分特征的分析，探讨虾塘养殖对他们的影响。结果如下：1）受虾塘养殖废水排放影响区中（直排区、修复区）红树林下沉积物TN与OM、TP呈正相关关系，虾塘养殖废水直排对林下沉积物具有明显酸化作用；2)NH4+-N是红树林下间隙水可溶性无机氮（DIN）的主要组成形式，无排放区沉积物还原性较强，更利于NH4+-N累积在间隙水中；NO3--N与DIN呈极显著相关，虾塘养殖废水排放增强了NO3--N、NO2--N和DIN的累积效应。研究结果表明沉积物和间隙水的理化性质可作为评价虾塘养殖区边邻红树林生境变化规律的定量指标之一。

Effects of shrimp aquaculture on the physiochemical properties of sediment and interstitial water in mangroves

Mangrove wetland plays an important role for pollution control and nutrient cycling in coastal marine ecosystems. Sediments, waters and vegetation work together and cooperate mutually to maintain the normal function of mangrove wetland ecosystem. Therefore, the understanding of nutrient characteristics in the sediments and interstitial water is instructive to evaluate the ecological function of mangrove wetland. In this study, three mangrove habitats beside to the shrimp pond aquaculture with different influencing degrees by the aquaculture wastewater discharge (non-discharge area, direct discharge area and restoration area) were taken as example, and their nutrient characteristics of sediments and interstitial water were analyzed to investigate the influence of shrimp pond aquaculture on mangrove ecosystem. The results showed that: 1) total nitrogen (TN), organic matter (OM) and total phosphorus (TP) have positive correlation in shrimp aquaculture effluent discharge habitats(direct discharge area, restoration area), and the effluent has obvious acidification effect on sediment; 2) NH4+-N is the main component form of dissolved inorganic nitrogen (DIN) in interstitial water of mangrove. The sediment of non-discharge area was more reductive, and which is more conducive to NH4+-N accumulation in interstitial water. NO3--N is significantly correlated with DIN, and the discharge of waste water reinforces the accumulative effect of NO3--N, NO2--N and DIN in sediment. These result indicated that the physicochemical properties of sediment and interstitial water can be used as one of the quantitative indicators to evaluate the mangrove ecosystem evolution that adjacent to shrimp aquaculture areas.