莱州湾海域营养盐现状及年际变化规律

Distribution and inter-annual variation of nutrients in Laizhou Bay

中文关键词: 莱州湾  小清河  富营养  磷限制  氮污染

英文关键词: Laizhou Bay  Xiaoqing River  Eutrophication  Phosphorus-limitation  Nitrogen pollution

中文摘要:

      通过对2006～2009年莱州湾调查数据分析，结果显示，2009年莱州湾海域5月和8月无机氮受小清河径流影响明显，西部海域显著高于东部海域；活性磷酸盐、活性硅酸盐5月受小清河径流影响明显，西部海域高于东部海域，8月影响不明显；5月，53.3%的海域内无机氮超四类海水水质标准，100%的海域内无机氮超一类海水水质标准。8月，34.9%的海域内无机氮超一类海水水质标准；活性磷酸盐含量总体偏低，只有5月小清河口海域超三类海水水质标准，其他海域均符合一类海水水质标准。无机氮年际变化结果显示，5月有逐步上升的趋势，8月有逐渐下降的趋势；活性磷酸盐5月变化不明显，8月下降趋势明显；活性硅酸盐5月和8月变化不明显。4年整个海域无机氮污染严重，磷缺乏；平均N/P为164、 Si/P为130、 Si/N为0.77；净营养盐收支呈磷减少而氮增加的总体变化趋势。

英文摘要:

      The inorganic nutrients in Laizhou Bay was monitored during 2006~2009. The results showed that due to the runoff of Xiaoqing River, the concentration of inorganic nitrogen in the western Laizhou Bay was significantly higher than that in the eastern area in May and August of 2009. Phosphate and silicate in the western Laizhou Bay were significantly higher than those in the eastern area in May, 2009, and no obvious variation in August. In May of 2009, concentrations of inorganic nitrogen in 53.3% of the seawater exceeded the fourth grade of Sea Water Quality Standard, and all samples exceeded the first grade. In August, concentrations of inorganic nitrogen in 34.9% of the seawater exceeded the first grade. Phosphate was generally at a low level; in May 2009 the seawater sample from the estuary of Xiaoqing River exceeded the third grade, and the other samples met the first grade. Combined data of inorganic nitrogen during 2006~2009 showed a gradually increasing trend in May and a decreasing trend in August. Phosphate did not change obviously in May but apparently declined in August. Silicate did not change significantly either in May or in August. The average ratios of nitrogen to phosphate, silicate to phosphate and silicate to nitrogen were 164, 130, and 0.77 respectively. Inorganic nitrogen pollution was serious, phosphorus was a potential limiting factor in the surveyed area, and this trend is supposed to go further in the future.