Yin Kedong, Harrison Paul J
Australian Rivers Institute, Griffith University Nathan Campus, Brisbane, QLD 4111, Australia.
Mar Pollut Bull. 2007 Jun;54(6):646-56. doi: 10.1016/j.marpolbul.2007.03.001. Epub 2007 May 18.
This study presents water quality parameters such as nutrients, phytoplankton biomass and dissolved oxygen based on 11 years of water quality data in Victoria Harbor and examined how the Pearl River estuary discharge in summer and year round sewage discharge influenced these parameters. Nutrients in Victoria Harbor were strongly influenced by both the Pearl River and sewage effluent, as indicated by the high NO(3) inputs from the Pearl River in summer and higher NH(4) and PO(4) in Victoria Harbor than both its sides. N:P ratios were low in the dry season, but increased to >16:1 in the wet season, suggesting that P is potentially the most limiting nutrient in this area during the critical period in the summer. Although there were generally high nutrients, the phytoplankton biomass was not as high as one would expect in Victoria Harbor. In fact, there were high concentrations of chl near the bottom well below the photic zone. Salinity near the bottom was lower in Victoria Harbor than at the two entrances to Victoria Harbor, suggesting strong vertical mixing within Victoria Harbor. Therefore, strong vertical mixing and horizontal advection appear to play an important role in significantly reducing eutrophication impacts in Victoria Harbor. Consequently, dissolved oxygen near the bottom was low in summer, but only occasionally dipped to 2 mgL(-1) despite the high organic loading from sewage effluent.
本研究基于维多利亚港11年的水质数据，呈现了营养物质、浮游植物生物量和溶解氧等水质参数，并研究了夏季珠江河口排放以及全年污水排放如何影响这些参数。维多利亚港的营养物质受到珠江和污水排放的强烈影响，夏季珠江的高硝酸盐输入以及维多利亚港内铵和磷酸盐含量高于其两侧均表明了这一点。旱季氮磷比很低，但在雨季增加到大于16:1，这表明在夏季的关键时期，磷可能是该地区最具限制性的营养物质。尽管营养物质总体含量较高，但维多利亚港的浮游植物生物量并不像预期的那么高。事实上，在光合层以下的海底附近叶绿素浓度很高。维多利亚港底部附近的盐度低于维多利亚港的两个入口处，这表明维多利亚港内存在强烈的垂直混合。因此，强烈的垂直混合和水平平流似乎在显著减轻维多利亚港的富营养化影响方面发挥了重要作用。结果，夏季海底附近的溶解氧较低，但尽管污水排放带来了高有机负荷，溶解氧仅偶尔降至2mg/L。
