【作者】 李春强；

【导师】 彭明；

【作者基本信息】 华南热带农业大学 ， 生物化学与分子生物学， 2007， 硕士

【摘要】 2005-2006年对三亚红沙港海域进行7个航次的调查,选了3个具有代表性的航次(春、夏、秋)数据对该海域的环境质量作出评价。结果表明,红沙港无机氮普遍劣2类水质标准,47%劣3类水质标准,33.3%劣4类水质标准,特别是夏季大部分属4类水质,整个港湾无机氮污染严重。红沙港活性磷酸盐基本符合2类海水水质标准,部分劣2类水质标准,13.3%劣4类水质标准。该港pH、DO尚属正常, COD基本符合2类水质标准,但铁含量偏高。叶绿素a含量虽尚属正常,但夏季偏高。红沙港平均营养状态指数(E值)在3.66～4.33,呈重富营养化。有机污染状况除湾口轻度污染外,其余测站均在中度污染以上,全年有53.3%站位处于严重污染。研究指出红沙港海水养殖自身污染、沿岸生活污水的排放及入湾径流是造成该水域富营养化的主要原因。认为目前红沙港水质已不能满足该海域功能区划提出的要求,需进行综合整治。在对三亚红沙港海域进行调查期间,监测到2次赤潮,一次发生在2006年4月至5月,另一次发生在2006年7月。我们对发生在2006年4月27至5月4日的中肋骨条藻赤潮生消动态过程进行跟踪监测,分析了中肋骨条藻赤潮发生过程中环境因子的变化规律,研究了赤潮藻生物量变化与环境因子的消长关系。结果表明:该港湾表层水体溶解态无机氮、无机磷、可溶性铁等含量高,为赤潮的发生提供了必需的营养基础;赤潮发生前持续的降雨过程使水温升高,盐度降低,有利于中肋骨条藻的快速增殖并导致了赤潮的爆发,降雨过后持续高温、静风天气使赤潮得以发展,随后磷、硅的耗尽使赤潮逐步走向消亡。应用相关分析、回归分析和主成分分析,分析了赤潮的发生机制,结果显示:影响本次赤潮的重要环境因子有水温、磷酸盐、硅酸盐、铁。鉴于红沙港受到的污染和频繁爆发的中肋骨条藻赤潮情况,我们建议对该港进行综合整治,同时,进行赤潮生物防治的研究。提出利用种植红树、养殖滤食性贝类、种植麒麟菜及微生物底质改良等手段,对该港进行生态治理,以期达到可持续防控的目的,同时为热带港湾赤潮可持续防控提供范例。红树林对污水具有净化功能,同时对其它植物存在化感作用,比较了几种红树植物粉对中肋骨条藻生长的影响,研究了红树粉及水浸液对中肋骨条藻生长的影响,以及红树根系分泌物(无土栽培营养液)对中肋骨条藻生长的影响。结果表明,红树粉、红树粉水浸液、红树根系分泌物对中肋骨条藻生长均有明显的抑制作用。红树对中肋骨条藻生长存在化感作用,化感作用的强弱与红树总酚的含量不成正比,提示可能存在其它化感物质同时在起作用。更多还原

【Abstract】 Seven number of voyages investigation data obtained from 2005 to 2006. The environment quality of Hongsha Bay in Sanya was analyzed and evaluated based on three number of voyages investigation data which were the most representative data reflecting the environmental status in spring, summer and autumn of Hongsha Bay.The results indicated that the concentration of inorganic nitrogen of almost 100% stations in three seasons was inferior to the GradeⅡof sea water quality standard, 47% of which stations was inferior to the GradeⅢof sea water quality standard and 33.3% stations was poorer than Grade IV of sea water quality standard. Especially, the contamination of inorganic nitrogen was heavy in summer in the whole Bay and was attributed to the GradeⅣof sea water quality standard. However, the concentration of active phosphate of most of investigated stations was belonged to the GradeⅡof sea water quality standard, while 13.3% of the stations did poorer than the Grade IV of sea water quality standard. The average nutritive indexes in each season was 3.66~4.33, presenting a heavy level of eutrophication. The majority of organic contamination was over medium, whereas that of 53.3% of the stations was heavy. The investigation also indicated that the discharge of industrial and agricultural waste water and the drainage of domestic sewage along the bay as well as the unorderly and excessive development of mariculture were the main factors resulting in eutrophication in the Hongsha Bay. It is necessary to control sewage draining and put more stress on protection of marine environment.During the investigation, two harmful algal blooms (HABs) were found; one occurred from April to May, another occurred in July. The process of Skeletonema costatum (S.costatum) bloom from 27 April to 4 May 2006 was monitored. We observed and analyzed the dynamic variety of environmental factors during this HAB, especially, the relationship between algae biomass density and environmental factors. The results indicated that the concentrations of dissolved inorganic nitrogen, inorganic phosphate and iron were high, which provided the necessary nutrient foundation for the outbreak of HAB. The persistent rain elevated water temperature and reduced the content of salinity before the HAB so that it conduced the rapid proliferation of S. costatum and resulted in the outbreak of this HAB. Then, the persistent high temperature and lack of wind after the rain promoted its development. Thereafter, the S. costatum bloom dissipated along with the exhaustion of phosphate and silicate. Three available statistical methods including correlation analysis, regression analysis and principal components analysis were used to determine the mechanism of HAB. The results showed that critical environmental factors, such as temperature,phosphate, silicate and iron levels, played important role in the process of the S. costatum HAB.In order to reduce the pollution and the HABs in Hongsha Bay, we adviced it is necessary to take measure on protecting the environment in the bay and doing the research of HABs prevention and cure. To sustainablely prevent and control occurrence of HABs effectively in tropical harbor,we suggested use ecology measures (such as planting mangrove, breeding seashell, fostering eucheuma cottonii and cultivating microbe which can improve marine sediment et al ) to prevent and cure the HABs in Hongsha Bay. Mangrove not only can cleanse sewerage but also have allelopathy to other plants. We studied the effect of mangrove powder, mangrove powder water steep, and mangrove root secretion on the growth of S. costatum. The results indicated that the growth of S.costatum was inhibited by mangrove powder, mangrove powder water steep and mangrove root secretion. We found that mangrove have allelopathy to the growth of S.costatum. Furthermore, there were not positive proportion between the effect of allelopathy and the content of total hydroxybenzene in mangrove plants, which implied that there was some other allelopathy substance in mangrove plants.更多还原