西江广东鲂产卵场水质营养盐现状与评价

2003-2006年在西江广东鲂(Megalobrama hoffmanni)主要产卵场-封开青皮塘渔场和郁南罗旁渔场的6个点,进行了4次水质监测,据此分析水域营养现状与污染情况。结果表明,青皮塘和罗旁渔场水域溶解氧充足,化学需氧量较低,受到耗氧有机物的污染较小,无机磷浓度均低于《地表水环境质量标准》(GB 3838-2002)Ⅲ类水质标准;两产卵场无机氮(DIN)含量均较高,近4年单因子指数均大于1,水域DIN浓度均高于《地表水环境质量标准》Ⅲ类水质标准,部份监测点超过Ⅴ类,两产卵场主要受氮污染。采用营养指数法及有机污染指数法进行综合评价,两产卵场的水质均达到了清洁水平。

Trophic Status and Assessment in Megalobrama hoffmanni

From 2003 to 2006, we had surveyed the nutrient salts in the Megalobrama hoffmanni main spawning grounds located in Feng Kai Qingpitang and Luo Pang in Xijiang river, and there were 6 sites in the spawning sites. Based on these data,the character of nutrients distribution and the status of eutrophication were analyzed. The results show that, in both waters the DO are all sufficient, and COD has the low level which the organic pollution of oxygen consumption is small and the inorganic phosphorus concentrations are lower than grade 3 surface water quality standard. But the level of DIN in the water is all above normal, nearly four years of single factor index exceeded 1, the DIN in the water meanly exceeded grade 3 surface water quality standard, and even exceeded grade 5 quality standard at some sites. The two spawning grounds are mainly polluted by nitrogen nutrient. Using nutrition index method and the organic pollution index evaluation method for two spawning grounds comprehensive evaluation, the results told us that the comprehensive quality about the two spawning grounds achieve optimum nutrition standards to clean water.