人工岛对金梦海湾水体交换的影响

为研究金梦海湾人工岛的不同布局对周围海域水动力及水体交换的影响,基于MIKE软件建立三维和二维潮流模型以及保守物质输运模型,运用欧拉法计算水体滞留时间,从整体和分区二个方面分析人工岛对水体交换的影响机制.结果表明：海螺岛工程起到分流、导流的作用,提升了金梦海湾的水体交换能力,水体交换率提升10.17%;海螺岛和进岛路的联合作用,使金梦海湾形成一个水体交换能力较差的半封闭式水域,水体交换率下降7.73%;在建设人工岛时保留潮汐通道有助于该区域的水体交换,进岛路的去除为汤河口和金梦海湾近岸增加一条潮汐通道,水体交换能力增加17.90%;在弱潮流地区,需考虑余流的作用.金梦海湾区域的余流小,潮流弱,因此保守物质滞留时间长,水体交换缓慢,水体的自净能力低.     

铅稳定同位素在沉积物重金属污染溯源中的应用

稳定铅同位素是示踪环境重金属来源的重要手段.通过分析测定泉州湾周边地区常见端元组分及采集自泉州湾洛阳江河口潮间带24个表层沉积物的稳定铅同位素组成,利用铅同位素的指纹参数对沉积物中铅的来源进行示踪.结果表明,潮间带沉积物中的铅主要受汽车尾气、工业生产和污水排放的影响.其中,位于交通繁忙区的采样点因为受到工业及汽车尾气排放的双重影响,污染最为严重.不同来源端元的稳定铅同位素组成相差较大,利用端元组分及沉积物206 pb/207 Pb和208 Pb/(206 Pb+ 207 Pb)比值的差别,可以追溯沉积物中铅的来源.     

不同雨强下黄棕壤坡耕地径流养分输出机制研究

为揭示三峡库区坡耕地在不同雨强下氮、磷养分随地表径流和壤中流的输出规律,在香溪河流域选择具有代表性的黄棕壤坡耕地进行原位人工模拟降雨试验.结果表明,在降雨总量一定的情况下,随雨强的增大,地表径流量、径流总量、泥沙侵蚀量均呈明显的增加趋势,而壤中流流量减少.不同雨强下地表径流中TN、DN、DP均存在明显的初期径流冲刷效应,TP在整个降雨过程中波动较大,呈微弱降低的变化趋势;壤中流中TN、DN、DP随降雨持续输出浓度无明显变化,TP在径流初期出现浓度峰值,之后减少并趋于稳定.雨强对磷素的影响更直接,雨强越大,磷素径流浓度也越大,氮、磷养分的平均浓度均远超出水体富营养化阈值.随雨强的增大,TN径流流失量减小,TP流失量增大,TN随地表径流流失贡献率随雨强的增大由36.5%增加至57.6%,磷素以地表径流为主,贡献率达90.0%以上,因此,控氮关键是减少壤中流的产生,控磷则需防止土壤侵蚀.随雨强的减小,地表径流中以溶解态流失的氮素比例升高,壤中流中均以溶解态为主,磷素的流失在不同雨强和径流形式下均以颗粒态为主.     

胶州湾、套子湾及四十里湾表层沉积物中有机氯农药的含量和分布特征

从胶州湾、套子湾及四十里湾海域和邻近河流采集了48个表层沉积物样品,采用气相色谱的分析方法对沉积物中有机氯农药(HCHs、HCB和DDTs)进行了测定,目的是探讨其在该研究区域的分布特征和来源.结果表明,胶州湾HCHs、HCB与DDTs的含量平均值分别为0.33、0.31和10.33 ng·g-1;套子湾及四十里湾的平均值分别为0.26、0.10和4.56 ng·g-1.相对于国内其他海域,胶州湾沉积物中OCPs偏高,特别是DDTs的含量;而套子湾及四十里湾沉积物中OCPs含量水平较低.对OCPs的分布特征及其来源进行分析得出,研究区域HCHs主要是历史残留,但是个别站位高含量的γ-HCH则表明了存在林丹的点污染源;而DDTs主要来源于工业DDTs,但是在胶州湾青岛港附近的站位o,p’-DDT/p,p’-DDT较高,暗示该区域受到三氯杀螨醇类型DDTs的污染.胶州湾高含量的DDTs需要引起足够的重视.     

三沙湾海水中磷的分布和富营养化研究

根据2010、2011年三沙湾水质监测资料,评价了活性磷酸盐的分布及时空变化特征,根据N/P和Si/N比判断三沙湾浮游植物生长的限制因子,用营养状态指数评价该湾水体的富营养化状态.结果表明,霍童溪为三沙湾海水中磷的主要陆源输入来源,磷为三沙湾植物生长繁殖限制因子,磷含量季节周期变化特征明显,5月植物生长繁殖旺盛,由于磷的匮乏,生长受到限制,磷含量降至最低水平,8月由于植物腐败分解释放磷和海水水温较高抑制植物生长,使磷含量升高,11月至次年1月,磷含量持续升高.三沙湾内富营养化指数大于1,存在发生赤潮的风险.     

粒级-标准偏差法和主成分因子分析法在粒度敏感因子提取中的对比

沉积物全样粒度参数已很难对受不同物源和不同沉积动力影响的古环境进行深入研究,不同来源的多组分分离提取敏感粒级方法较多,不同的方法提取的粒级兼容性及其所反映的环境意义差别值得探讨。本文利用烟台四十里湾3个柱状沉积物粒度分析数据为基础,对比分析粒级-标准偏差法和主成分因子分析法提取的环境敏感因子及其反映的古环境意义。结果表明,两种方法提取的环境敏感因子粒级一一对应,两种方法所提取的敏感粒级含量在沉积物中存在相同的变化趋势,这说明了两种方法均能敏感地反映沉积物相同的沉积动力特征,但粒级-标准偏差法所提取的粒级易受端元组分影响,粒级-标准偏差法所提取的敏感因子主要反演主控因子环境信息。     

Assessing biomass gains from marsh restoration in Delaware Bay using Ecopath with Ecosim

The Delaware Bay ecosystem has been the focus of extensive habitat restoration efforts to offset finfish losses due to mortality associated with power plant water intake. As a result, a 45 km² or a 3% increase in total marsh area was achieved by 1996-1997 through the restoration efforts of the Public Service Enterprise Group (PSEG). To quantify the impact of restoration efforts on system productivity, an Ecopath with Ecosim model was constructed that represented all major components of the ecosystem. The model consisted of 47 functional groups including: 27 fish species, 5 invertebrate groups, 4 multi-species benthic groups, 6 multi-species fish groups, 3 plankton groups, 1 shorebird group and 1 marine mammal group. Biomass, abundance, catch, and demographic data were obtained from the literature or from individual stock assessments conducted for principal ecosystem components. A base Ecosim model was fitted to time series of key species in the Bay representing the period 1966-2003. To access the gains from marsh restoration, model simulations reflecting no restoration were conducted to estimate the productivity that would have been lost if restoration efforts had not occurred. The results indicated that restoration increased total ecosystem biomass by 47.7 t km⁻² year⁻¹. Simulations indicated increased biomasses across a wide range of species including important forage and commercially important species. The marsh restoration also significantly impacted ecosystem structure increasing the ratio of production-to-respiration, increasing system path length and decreasing the ratio of production-to-biomass.     

海洋环境承载力与生态补偿关系研究

21世纪是海洋的世纪,随着陆地资源的日渐耗竭,海洋资源的开发又成为新一轮的竞赛活动。本文以渤海为例,运用海域承载力与生态补偿2种理论探讨了在资源与环境成为制约经济发展两大瓶颈的条件下,如何在获取最大利益的同时保持海洋可持续发展,以期为海洋开发利用提供决策支撑。     

Characterization and seasonal distribution of microplastics in the nearshore sediments of the south-east coast of India,Bay of Bengal

• MPs in the coastal sediment of south-east coast of India are quantified. • High MPs are recorded near river mouths and nearshore regions. • Polyethylene and polypropylene are the major polymers observed. • MPs contamination is higher than the values reported elsewhere. In view of increasing Microplastics (MPs) contamination in the marine environment and dearth of baseline data, a study was conducted on the abundance, characterization, and seasonal distribution of MPs in the nearshore sediments of the south-east coast of India. Sediment samples (n = 130) were collected at a distance of 1 km and 10 km from the shore region at varying depths (8–45 m) along the Chennai to Puducherry coast (165 km stretch), representing two seasons, i.e., south-west (July 2019 and July 2020) and north-east (January 2020) monsoons. The average abundance of MPs at the 22 offshore sites along the Chennai to Puducherry coast varied from 9±4.3 to 19±12.9 particles/50 g dry weight, in July 2019 and January 2020, respectively. July 2020 had an average abundance of 10±4.5 particles/50 g dry weight. Spatially, high levels of MPs were found at 1km stations and transects in proximity to the river inlets, and temporally, the north-east month recorded the maximum concentration. The dominant morphotype was the filament, and the major polymers were polyethylene and polypropylene. Scanning Electron Microscope (SEM) images revealed the surface irregularity and degradation of MPs due to weathering. The study highlights that high sediment contamination by MPs occurs during heavy rainfall and accumulates closer to river inlets. Eventually, this study suggests that appropriate management of plastic wastes on the landside will reduce MP contamination in the marine environment.     

基于“美丽海湾”建设的“三线一单”编制实践--以儋州市环新英湾地区为例

编制“三线一单”(生态保护红线、环境质量底线、资源利用上线和生态环境准入清单)是深入打好污染防治攻坚战的基础。以儋州市为研究对象,衔接“美丽海湾”建设需求,从“三水”(水环境、水生态、水资源)协同角度提出解决儋州市重点海湾环新英湾地区突出生态环境问题的生态分区管控方案,重点讨论了基于陆海统筹原则的环新英湾地区“三线一单”编制重点和特色,提出了针对性的生态环境保护的对策建议,探索了一套符合沿海地区特色的生态环境要素分区管控方案编制方法,为其他沿海城市“三线一单”划定提供借鉴。