渤海海峡冬季表层海水中溶解无机碳分布特征分析

根据2010 年2 月—2010 年3 月的调查数据, 探讨了冬季渤海海峡及其附近表层海水中溶解无机碳体系的分布特征。结果表明: 表层水体中TA、DIC 和HCO₃^- 的浓度分布总体上呈现出海峡西南部高东北部低的分布趋势。西南部出现的高值区, 与该区域靠近莱州湾, 受莱州湾水体污染影响有关。调查海域TA 与表层水的温度相关性明显, pH 与叶绿素的相关性较高。水温和Chl-a 浓度是影响水体中无机碳体系分布变化的重要因素。其中, 水温对HCO₃^- 的影响要明显强于DIC。海峡南北两侧水体交换的差异, 是导致海峡南部东西两端无机碳体系各参数监测数值的差异明显大于海峡北部的主要原因。     

绿潮藻浒苔光合固碳与防治海水酸化的作用Ⅰ.光合固碳与海水pH值提高速率研究

以黄海绿潮暴发的主要漂浮种类浒苔 (Ulva prolifera)为材料,在实验室条件下研究了浒苔光合参数、固碳速率及提升海水pH的作用,结果表明:浒苔光合作用半饱和常数K_m为0.25 mmol/dm3,光合作用饱和时海水溶解无机碳(DIC)浓度也只需1.2 mmol/dm3,为正常海水DIC浓度(2.4 mmol/dm3)一半,故黄海绿潮暴发时藻体可以一直保持光合作用饱和与旺盛生长状态。水生条件下浒苔藻体主要吸收海水中的DIC,0.5 g/dm3培养密度下,1个光周期内净光合固碳速率为10.92 mg /(g·d)(鲜重)。连续培养5 d,0.5,1.0和2.5 g/dm3培养密度组的DIC浓度从22 mg/dm3分别降为4.85,2.62和0.66 mg/dm3,表明DIC去除率随藻体培养密度提高而增强,分别可达77.78%,88.00%,96.98%;藻体吸收海水中无机碳的同时可使海水pH升高,0.5 g/dm3培养密度下,1个光周期内净提升pH速率高达0.96/(dm3·g·d)。连续培养5 d,0.5,1.0和2.5 g/dm3培养密度组第1天其pH分别可达到9.1,9.2和9.7,表明藻体密度越高pH提升越快,而且第5天pH均可稳定在9.9左右。浒苔暴露在空气中可直接吸收空气中CO₂,1个光周期内其光合固碳速率约为46.14 mg/(g·d),而在海水中的光合固碳速率为10.92 mg/(g·d),可见浒苔在空气中的光合固碳速率是水中的4.23倍。水生和气生时单位质量藻体的固碳效率因藻体间相互遮蔽而下降。结果可为今后黄海绿潮暴发机制及CO₂减排和防止海洋酸化作用的评估提供技术支撑。     

渤海湾渔业碳汇分析与预测初探

为了解渤海湾近十年来渔业碳汇能力,本研究汇总了渤海湾地区2010-2020年海水养殖的品种和产量。通过建立不同养殖品种固碳能力评估体系,计算了不同养殖品种对渔业碳汇的贡献和渤海湾近十年海水养殖固碳总量。结果表明,2010-2020年渤海湾海水养殖以池塘养殖为主要养殖模式,年固碳量从2010年的5.79万吨增至2020年的11.04万吨,十年内共计固碳96.0万吨,平均碳转化比为12.5%,其中山东省贡献超过65%。该探索对建立“渔业碳汇”计算的指标体系、科学发展碳汇渔业、提升海洋碳汇生态价值具有一定的指导意义。     

沙海蜇(Nemopilema nomurai)消亡过程中海水溶解氧变化的模拟研究

采用实验室模拟的方法,研究了不同海水温度、盐度、pH、N/P比下,沙海蜇消亡过程中海水溶解氧的变化特征,这对探讨水母灾害性暴发后消亡的环境影响有重要的科学意义。研究结果表明,沙海蜇的消亡可引起海水溶解氧浓度的显著降低,不同海水温度、盐度、pH、N/P比条件下沙海蜇消亡引起的海水溶解氧浓度的降低无显著差异,但与没有沙海蜇消亡时,海水溶解氧的变化相比则差异显著。沙海蜇消亡一般需要6—7天时间,在高N/P比的海水中,沙海蜇的消亡时间延长。沙海蜇的消亡造成水体的严重缺氧,水体氧饱和度低于20%,从第2天到第3天,本底海水、不同过程温度、盐度、pH条件下,消耗水体氧的量剧增,第6天达到峰值,但不同N/P比条件下,水体溶解氧的降低在第2天即可达到一个耗氧的高值,一直持续到第7天出现峰值;海水温度、盐度、pH、N/P比变化,可导致沙海蜇的消亡过程中水体氧消耗量的变化,就这四种影响因素而言,其平均最大耗氧量从大到小的顺序是:温度(23—30℃区间段)>pH(5.0—9.0区间段)>盐度(21—33区间段)>N/P比(16:1—240:1区间段),分别为39.9、39.7、38.0和35.9mg/(kg.d),相对而言,水体温度和pH对沙海蜇消亡过程中氧消耗量影响较大,水体N/P比和盐度影响较小。所以,沙海蜇消亡过程中,由于海水温度和pH的变化形成的低氧区更为严重,而且在当今富营养化(高N/P比)的近海水域中,水母的消亡高耗氧的时间加长,对海水环境造成的影响更为严重。     

小长山岛3种大型海藻组织碳、氮含量和δ15N值的环境指示意义

大型海藻组织碳、氮含量及δ¹⁵N值的变化对于指示营养盐来源及营养盐评价研究具有重要的意义。为探究大型海藻组织碳、氮含量及δ¹⁵N值的变化特征,于2020年7月至2021年6月逐月分析了小长山岛潮间带孔石莼（Ulva pertusa）、角叉菜（Chondrus ocellatus）、鼠尾藻（Sargassum thunbergii）3种大型海藻组织的碳、氮含量和δ¹⁵N值的变化,并对其生长环境中海水的理化因子进行了测定。结果发现：孔石莼组织的氮含量与海水中的NO₃-N和DIN含量之间存在显著的相关性,角叉菜组织的氮含量与海水中的NH₃-N含量之间也存在显著的相关性。然而,大型海藻组织的碳含量和C/N比值与海水中的碳、氮营养盐之间并无显著的相关性。孔石莼组织的δ¹⁵N值与海水中的NO₃-N和DIN含量之间也存在显著的相关性。因此,孔石莼适于用作NO₃-N和DIN来源的指示藻种。结果指示小长山岛潮间带海水中具有供大型海藻生长利用的充足的营养盐,其主要受到生活污水和养殖排放的影响。     

南极普里兹湾沉积物中的糖类分布及意义

利用中国第18和21次南极考察获取的南极普里兹湾沉积物样品,分析了其中的有机碳和糖类物质的含量及组成,结果表明糖类和有机碳的分布受上层水体的初级生产、地形条件和水体垂直稳定度等多种因素的控制。表层沉积物中糖类物质的平均含量为3.03 mg/g,最高值为5.60mg/g,出现在湾内的毗邻陆架区。沉积物有机碳含量与表层海水叶绿素a具有良好的相关性,能够反映上层水体初级生产的变化。单糖组分的研究可以判定其生源母质,沉积物中有机质的来源主要是海洋上层生物。糖类是易被降解利用的有机质,通过糖类物质中六碳糖的比重及其垂直分布的变化可以判断出不同站位沉积速率的相对快慢。     

模拟研究沙海蜇消亡过程中海水pH 变化及对海水酸化的影响

通过室内模拟实验,研究了不同pH、盐度、温度和氮磷比控制条件下沙海蜇(Nemopilema nomurai)消亡过程中水体pH的变化特征及对海水酸化的影响.结果表明,沙海蜇块体分解会造成pH的显著降低,水体出现明显酸化.随着沙海蜇的分解,本底海水组(本底海水+实验用沙海蜇)水体pH呈现先下降,后缓慢回升直至稳定的趋势,并在第2天形成最小值,且水体pH下降0.5～1.3.沙海蜇块体在不同pH、盐度、氮磷比、温度控制条件下分解时,水体pH变化趋势相似,均表现为先下降,达到最小值后再缓慢回升,但不同控制条件下水体pH出现最小值的时间并不一致,从先到后的顺序是温度组(第3天)、pH和盐度组(第4天)及氮磷比组(第5天),这与沙海蜇块体分解速率顺序一致.沙海蜇分解过程中,这4个实验组水体pH下降0.5～1.8,水体发生明显的酸化,这其中海水盐度、pH的变化及温度的降低所导致的沙海蜇消亡过程中海水酸化程度比较严重;因此,在当今海水富营养化及海水温度升高的情况下,沙海蜇的暴发及其消亡会造成海洋生态系统遭受更严重的破坏.     

改性钢渣吸附海水中汞的影响因素研究及安全性评价

本文研究了未改性钢渣和酸改性、碱改性、热改性以及盐改性等4种改性钢渣在不同振荡时间、海水中汞初始浓度和温度条件下对汞的吸附效果,并探讨了钢渣对海水pH值、营养盐浓度以及重金属浓度的影响。实验显示未改性钢渣和4种改性钢渣在120min振荡时间、15～35℃条件下对海水中汞去除效果均比较好,酸、碱和热改性钢渣可以更好地适应海水中汞浓度的变化。在常温下,碱改性钢渣对海水中汞的去除效果最好,去除率可达91.9%,同时会使砷、铜、铅、锌和镉等重金属浓度下降。结果表明,碱改性钢渣治理海洋重金属的效益好且安全性较高,可考虑应用于实际海洋工程。     

模拟添加氮对海水溶解无机碳体系的影响

碳和氮作为主要的生源要素对维持海洋生态系的正常运转起着至关重要的作用,碳与氮的变化是相互耦合的且呈双向作用,为探讨海水无机碳与氮的相互作用规律,研究了室内模拟添加硝酸盐对海水无机碳体系pH、溶解无机碳(DIC)、HCO3-、二氧化碳分压(Pco2)的影响。结果表明,在室内培养的条件下,单纯添加硝酸盐(增加至原海水硝酸盐浓度的5-20倍)可引起培养体系浮游生物量的变化,但不能引起海水pH及DIC、HCO-3含量的明显变化,对DIC而言,其变化率仅仅在1%以内,但可导致海水Pco2的相对明显升高,其最终结果导致海水碳汇强度的减弱,碳源强度的增加。     

海水酸化和热应激对日本鼓虾氧化应激和能量代谢的影响

伴随着全球气候变化的日益加剧,过量CO₂排放所导致的海洋酸化和暖化现象已引起广泛关注。本研究设置了两个pH水平（pH 8.1和pH 7.6）和两个温度梯度（20.0和23.0℃）,以探讨海水酸化和温度升高对日本鼓虾（Alpheus japonicus Miers）氧化应激和能量代谢过程的影响。结果发现,海水酸化、热应激以及海水酸化和热应激复合胁迫能够诱导日本鼓虾产生不同程度的氧化应激现象,且海水酸化和热应激对过氧化氢酶（Catalase,CAT）活性、还原型谷胱甘肽（Glutathione,GSH）含量和还原型谷胱甘肽与氧化型谷胱甘肽比值（Glutathione/Oxidized Glutathione,GSH/GSSG）有交互作用;其中,海水酸化和热应激复合暴露导致鼓虾GSH含量较对照组水平降低了66.0%,GSH/GSSG比值降低为对照组水平的20.8%,而脂质过氧化水平则较对照组显著增加了51.4%。此外,海水酸化和热应激复合暴露能够导致日本鼓虾己糖激酶（Hexokinase,HK）活性的显著增强和蛋白质含量的显著降低,提示鼓虾通过调节糖酵解过程和能量储备来满足机体的能量代谢需求。上述结果表明,短期海水酸化和热应激暴露能够影响日本鼓虾的抗氧化防御体系、能量代谢过程以及能量储备能力,长期持续暴露可能会对其种群维持构成潜在威胁。     

东海颗粒碳的垂直转移过程

在１９９３年和１９９４年两个航次中，利用震动式取样从东海陆架取得３个柱状岩芯样品。对其进行了ＰＯＣ，ＰＩＣ，ＰＯＮ含量和粒度分析，并同其上覆水体的ＰＯＣ，ＰＩＣ以及总颗粒物的垂直通量和悬浮体作了比较。     

海水ORP对3C钢腐蚀行为的影响

研究了氧化还原电位(Oxidation Reduction Potential, ORP)对海水中碳钢腐蚀电化学特征的影响,应用动电位极化曲线法探讨了 ORP 与碳钢腐蚀行为之间的关系。结果表明,海水的 ORP 参数对碳钢腐蚀行为具有较大的影响,其中 O2/OH?电对的作用占主导,其他电对如 Fe3+/Fe2+也有一定的影响。随着海水 ORP 的增大,其氧化能力越强,碳钢腐蚀电流增大,腐蚀速度加快。水质相对稳定的开放性大洋海水中,可以考虑海水氧化还原电位在碳钢腐蚀速度预测评估中的应用。     

Mobilization of metals from riverine suspended matter in seawater

Suspended matter from rivers in the Russian Far East was leached by seawater to assess the extent of Zn, Cd, Pb, and Cu release from the land-derived solids to estuarine and coastal waters. The concentration of solids in the leaching experiments was 0.25 g/l. The suspended matter used varied in metal content from background levels to heavily contaminated.The concentration of Zn, Cd, Pb, and Cu in the leaching solution after 1, 4, 24, 48, and 96 h was determined by anodic stripping voltammetry. Measurable Cd was transferred from river suspended matter to seawater with both background and elevated Cd concentrations, though the amount of Cd released was different. The increase in Zn and Pb in solution was observed only at the enriched concentration of metals in the suspended solids. The Cu transfer into solution was more pronounced from material with elevated Cu concentration, but the amount of degradable organic matter in the solid phase was more important.The losses of metals from the riverine solids varied from 60% to 80% of total concentration for Cd to negligible for Pb, independent of contamination. The Zn loss depended on the initial concentration in the solids and decreased from 11–16% for the heavily contaminated suspended matter to 3–8% for the moderately enriched ones and to negligible for the pristine solids. Cu loss varied from 1% to 30% of total content, with no clear dependence on concentration in the suspended matter.The significance of additional input of dissolved metals to estuarine and coastal waters from remobilization was assessed by comparison with the initial concentration of dissolved metals in river water. Such experiments could be used to assess the water quality impact of atmospheric fallout of contaminated solids and storm drainage from the urbanized areas, in addition to river suspended matter studies.     

Analysis of lead in polluted coastal seawater

The concentrations of total lead were determined in both ordinary coastal seawater and in coastal waters highly polluted with sewage. The average concentration of total lead ranged from about 25 ng/kg in surface samples of the former type to an average of 150 ng/kg in the latter type. 0.4⁻μm filtrate lead was found to be equivalent to lead extracted from untreated seawater by dithizone in chloroform. In highly polluted waters, particle lead ranged from 56 to 39% of the total lead, with the proportion increasing as the amount of sewage in the seawater increased. Virtually all of the lead in sewage is contained in the particle phase before it enters the ocean but about 11% is made freely available by cation exchange when the sewage is mixed with seawater. In ordinary coastal waters that are not highly polluted with sewage lead, particle lead ranged from 90 to > 20%, and most of this lead was associated with plankton. About one-third of total lead, or one-half of particle lead, in untreated seawater adheres to the walls of the water container within the first day. Upon prolonged standing (> 3 months) most of the remaining particle lead can be collected on the surface of algal colonies growing on the walls of the water container. The concentrations of freely available lead in seawater do not seem to be significantly affected by wall adsorption. The ²⁰⁶Pb/²⁰⁷Pb ratio of total lead in coastal surface seawater collected near Los Angeles was 1.194, and a day earlier was 1.188 near La Jolla. It is believed that this shows lack of mixing of contributions from two different sources of lead pollution: a pulse of rain-storm runoff of gasoline lead(²⁰⁶Pb/²⁰⁷Pb 1.197) from paved surfaces added to Los Angeles waters; and sewage lead (²⁰⁶Pb/²⁰⁷Pb 1.188) from San Diego added to La Jolla waters.     

Relating coral species traits to environmental conditions in the Jakarta Bay/Pulau Seribu reef system, Indonesia

A key question in ecology is how biological traits of species determine their locations within an ecosystem. Identifying associations between species traits and environmental variables can help us to understand the causes of disturbance and predict whether species with given traits will persist under changing environmental conditions. To this end corals and environmental variables were sampled in 20 patch reefs of Pulau Seribu, located to the northwest of Jakarta, Indonesia. RLQ analysis, a multivariate ordination approach was subsequently used to relate species traits (colony shape, colony form, corallite size, reproductive mode and adaptive strategy) to environmental variables (e.g., heavy metal concentration in seawater and sediment, salinity, dissolved oxygen, and the cover of sand, dead coral, algae, sponges and soft corals). Using RLQ analysis, we identified environmental gradients associated with significant variation in species traits. Stress tolerant species with a massive morphology, meandroid shape and large corallites were associated with sites with a high abundance of algae and a relatively high concentration of potentially toxic heavy metals in seawater including Cu and Cd, whereas ruderal species and species with a branching morphology and very small corallites were linked to midshore sites. Competitively dominant species with a laminar or free-living morphology, phaceloid shape, very large corallites and brooding reproductive mode were linked to offshore sites with abundant Ca and Sr in the sediment and a high cover of Halimeda algae and sponges. Results of this study indicate that disturbance has differentially affected the marine environment of the Pulau Seribu system, which in turn interacts with coral species traits to determine local species composition.     

动态海水中保护电位对钙质沉积层形成的影响

采用恒电位阴极极化和线性极化法研究了天然海水中不同动态条件、不同初始保护电位下,阴极保护初期碳钢表面钙质沉积层的形成规律。扫描电镜(SEM)和能谱X-射线分析(EDX)分析了保护后碳钢表面的产物。结果表明:-800 mV(vs.SCE,下同)保护电位下,在静态和动态海水中碳钢表面形成的钙质沉积层质量都较差;-900 mV保护电位下,静态海水中形成致密的钙质沉积层,动态下钙质沉积层形成困难;-1 000 mV保护电位下,静态和动态海水中都形成良好的钙质沉积层。随流速增大,阴极保护电流密度显著增大,钙质沉积层中Ca/Mg比值增加;动态条件下,较负的保护电位,有利于阴极保护初期钙质沉积层的形成。     

海水流动对A3钢腐蚀速度的影响

为了定量考察海水的流动对钢铁材料在海水中的腐蚀速度的影响,通过室内和实海挂片失重测试比较了A3钢在静止和流动海水中的腐蚀速度差异,并在控制流速条件下使用动电位法测试了A3钢的腐蚀速度,同时测试了不同流速海水中的环境参量。室内和实海挂片失重测试比较结果表明,海水流动能够加快A3钢在海水中的腐蚀速度,腐蚀初期尤其明显。在控制流速条件下采用动电位极化方法测试了腐蚀初期A3钢的腐蚀速度,并且通过拟合处理得到了海水流动对其腐蚀速度影响因子的表达式。     

目标样本粒度判据在海湾环境演变研究中的运用——以福建前湖湾为例

高密度采集福建前湖湾海岸剖面133个泥沙样品做粒度分析,其频率曲线显示多种粒度分布特征,预示多种沉积环境的变化。采集研究剖面周边海滩、河口浅滩、河口、滨海沼泽和海岸沙丘等已知环境的样品作为目标样本。将目标样本沉积参数平均粒径(Mz)、标准偏差(σ)、峰态(Kg)设为判别参数,利用Excel计算海岸剖面样品与目标样本参数的距离,筛选最小距离样品,归为已知目标样本的同类。据此,分析了海岸剖面蕴含的6个沉积环境变化阶段。利用剖面底部淤泥测年14C=(328 15±170)a BP,和剖面上部泥炭测年14C=(24 130±100)a BP,了解这一变化发生的年代。自(32 815±170)a BP以来,前湖湾经历了河口浅滩-河口、沙丘-河口-滨海沼泽-海滩-沙丘等海岸环境演变过程。