蓝藻水华优势藻高效防控铜制剂的筛选

在对比络合铜、有机铜和无机铜3类5种典型铜制剂对蓝藻水华优势藻--铜绿微囊藻(Microcystis aeruginosa)和2种非靶标藻种--普通小球藻(Chlorella vulgaris)和斜生栅藻(Scenedesmus obliquus)的96 h生长抑制效果的基础上,进一步开展了3类铜制剂抑制铜绿微囊藻生长的15 d延长效应研究.试验结果表明,质量分数为25%的络氨铜水剂、30%琥胶肥酸铜可湿性粉剂和20%乙酸铜可湿性粉剂对蓝藻水华优势种有较好的生长抑制效果,其对初始密度为2×105～4×105mL-1铜绿微囊藻的96 h半抑制浓度(以下均以有效成分的质量计)分别为0.03、0.06和0.05 mg·L-1,且初始藻密度对抑藻效果并无明显影响.试验质量浓度为0.25 mg·L-1的25%络氨铜水剂、0.30 mg·L-1的30%琥胶肥酸铜可湿性粉剂或0.20 mg·L-1的20%乙酸铜可湿性粉剂均能抑制铜绿微囊藻增长,且在0～15 d内都不会出现藻细胞再次复苏和增长.此外,由于铜制剂对铜绿微囊藻的96 h半抑制浓度远低于其对普通小球藻和斜生栅藻的96 h半抑制浓度,因此可在有效控制靶标藻种的同时不对非靶标藻种的生长造成严重威胁.络氨铜、琥胶肥酸铜、乙酸铜有望被开发成为高效、绿色的蓝藻水华控制剂.     

蓝藻发酵生产微生物农药的影响因素研究

采用摇瓶发酵试验探讨了蓝藻为原料制备苏云金杆菌生物杀虫剂的可行性,并考察了不同培养条件（蓝藻含固率、种龄、接种量、初始pH、摇床转速、发酵温度）对苏云金杆菌生长增殖、产孢与产毒效果的影响。研究结果表明,无需任何预处理工序,Btk 130菌株能在蓝藻为唯一原料的培养基中正常生长发育,并且产孢产毒。发酵48 h后,芽孢产率达到86.7%,远高于常规培养基;生物毒效为282 IU.mL-1,与常规培养基相当。培养条件优化结果表明,在蓝藻含固率为2%、初始pH为7.0、接种物种龄为9 h、接种量为2%、培养温度为30℃、摇瓶转速为200 r.min-1的条件下培养48 h,Btk 130可达到较好的发酵效果,活菌数及抗热芽孢数可达7.32 CFU.mL-1和6.38 CFU.mL-1,生物毒效为528 IU.mL-1。该研究不仅为蓝藻提供了高附加值的处置新途径,而且可显著降低生物杀虫剂的生产成本,具有广阔的应用前景。     

邻苯二甲酸二丁酯对海洋微藻生长的影响

近年来,内陆和近海水体中的一种典型环境激素邻苯二甲酸二丁酯(DBP)含量显著上升,但其对海洋生态系统的影响并不明确。本研究选取7种海洋微藻为实验材料,包括1种甲藻(东海原甲藻Prorocentrum donghaiense),2种定鞭藻(小普林藻Prymesium parvum和球形棕囊藻Phaeocystis globosa),2种硅藻(中肋骨条藻Skeletonema costatum和三角褐指藻Phaeodactylum tricornutum),以及1种隐藻(红胞藻Rhodomonus salina)和1种绿藻(海洋小球藻Chlorella sp.),设置5个DBP暴露浓度(5、10、20、50、100μg·L-1),研究其对海洋微藻生长的影响,并探索DBP暴露对微藻抗氧化系统和光合系统的影响。结果表明:在所有暴露组中,球形棕囊藻、小普林藻、东海原甲藻、红胞藻、海洋小球藻生长速率显著增加;5~20μg·L-1的DBP暴露下中肋骨条藻不受影响,50、100μg·L-1下受到抑制;所有DBP暴露组对三角褐指藻没有显著影响。在50μg·L-1DBP暴露下,随着时间的延长,球形棕囊藻的SOD、CAT、MDA均表现出先升高后下降的趋势,第7天藻的叶绿素a、叶绿素b,类胡萝卜素含量较对照组分别增加了23%、10%、48%,球形棕囊藻光系统II(PSII)的最大光能转化效率(Fv/Fm)、PSII的潜在活性(Fv/F0)、光合性能指数PI分别增加了4.8%、16%、69%。研究发现DBP对海洋微藻的影响具有种间差异性,能够显著促进有害赤潮藻球形棕囊藻的生长,近岸水体DBP含量的增加可能改变浮游植物群落组成,进而增加有害藻华暴发的风险。     

International standardized procedures for in vivo evaluation of multi-walled carbon nanotube toxicity in water

The classical approach in ecotoxicological evaluation of chemical substances consists of conducting standardized bioassays on organism models. In this work, the potential impact of industrial multi-walled carbon nanotubes was investigated by ecotoxicological standardized procedures using aquatic organisms of different trophic levels, namely bacteria, green algae, invertebrates, fish, and amphibians. The results indicated (1) inhibition of growth in amphibians at 50 mg L^?1 and higher, and (2) no effects on daphnia and fish up to 100 mg L^?1. With the exception of algae (for which Fe deficiency is measured), it seems that the observed toxicity may be due to physiological effects in relation to the ingestion of carbon nanotubes not necessarily related to their intrinsic effects.     

微藻对壬基酚的响应及去除能效研究

分离筛选11种微藻开展微藻对NP暴露的响应特征和去除能效研究。NP对叶绿素a含量的96 h半抑制效应浓度(EC50)介于0.60~3.33 mg·L~(-1)之间,EC50由小到大依次为:短棘盘星藻羊角月牙藻小球藻衣藻斜生栅藻肥壮蹄形藻卷曲纤维藻二尾栅藻惠氏微囊藻四尾栅藻蛋白核小球藻。除斜生栅藻、羊角月牙藻、肥壮蹄形藻、卷曲纤维藻之外,微藻的生长速率与EC50呈显著的正相关关系。EC50与细胞粒径、表面积以及体积总体上呈负相关关系,与微藻对NP的最大去除速率和半饱和常数呈正相关关系。NP的藻类去除过程符合一级反应动力学方程,且NP的半衰期与微藻起始总表面积呈显著的负相关关系。NP对微藻群落的影响与其浓度相关,其选择性干扰效应主要与微藻耐受性相关。NP耐受性高的种类多表现出高生长速率和去除能力。     

海洋中微塑料的环境行为和生态影响

微塑料一般指直径小于5 mm的微小型塑料颗粒或碎片,海洋中常见的微塑料类型主要包括聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯等。由于形状、颜色多变,分子量大,结构稳定,粒径范围与浮游植物相近,海洋中的微塑料很容易被对浮游植物、浮游动物和其他海洋动物等产生影响。微塑料还可以为病毒、细菌提供附着载体,影响浮游植物分布,进入海洋生物消化道或进一步转移到组织中对机体产生毒性效应,甚至通过捕食作用沿食物链传递,对高等动物及人类健康造成威胁。此外,微塑料可以作为海水中痕量化学物质的吸附载体,对生物产生联合毒性。根据目前对微塑料的研究进展情况,未来应加强对海洋微塑料分离、鉴定技术的研发以及海洋微塑料的生物毒性效应和生物传递效应机制等问题的研究。     

Microalgae Scenedesmus obliquus as renewable biomass feedstock for electricity generation in microbial fuel cells （MFCs）

Renewable algae biomass, Scenedesmus obliquus, was used as substrate for generating electricity in two chamber microbial fuel cells （MFCs）. From polarization test, maximum power density with pretreated algal biomass was 102mW·m^2 （951mW·m^3） at current generation of 276mA·m^-2. The individual electrode potential as a function of current generation suggested that anodic oxidation process of algae substrate had limitation for high current generation in MFC. Total chemical oxygen demand （TCOD） reduction of 74% was obtained when initial TCOD concentration was 534mg · L^-1 for 150 h of operation. The main organic compounds of algae oriented biomass were lactate and acetate, which were mainly used for electricity generation. Other byproducts such as propionate and butyrate were formed at a negligible amount. Electrochemical Impedance Spectroscopy （EIS） analysis pinpointed the charge transfer resistance （112Ω ） of anode electrode, and the exchange current density of anode electrode was 1214 nA·cm^-2.     

Social capital as a key determinant of perceived benefits of community‐based marine protected areas

Globally, marine protected areas (MPAs) have been relatively unsuccessful in meeting biodiversity objectives. To be effective, they require some alteration of people's use and access to marine resources, which they will resist if they do not perceive associated benefits. Stakeholders’ support is crucial to ecological success of MPAs, and their support is likely to depend on their capacity to adapt to and benefit from MPAs. We examined the influence of social adaptive capacity (SAC) on perceived benefits of MPAs in Siquijor, Philippines, in the Coral Triangle. This region has substantial biodiversity and a population of over 120 million people, many of them dependent on marine resources for food and income. The region has many MPAs, most of which are managed under decentralized governance systems. We collected survey data from 540 households in 19 villages with associated MPAs. We evaluated the influence of multiple SAC variables (e.g., occupational multiplicity and social capital) on perceived benefits with decision trees (CHAID) and qualitatively analyzed this relationship with respect to types and recipients of benefits. Our models revealed the key role of social capital, particularly trust in leadership, in influencing perceptions of benefits (χ² = 14.762, p = 0.000). A path analysis revealed that perceptions of distributional equity were a key mechanism through which social capital affected perceived MPA benefits (root mean‐square error of approximation = 0.050). Building social capital and equity within communities could lead to more effective management of MPAs and thus to expenditure of fewer resources relative to, for example, regulation enforcement.     

Managing conflicts between economic activities and threatened migratory marine species toward creating a multiobjective blue economy

Harnessing the economic potential of the oceans is key to combating poverty, enhancing food security, and strengthening economies. But the concomitant risk of intensified resource extraction to migratory species is worrying given these species contribute to important ecological processes, often underpin alternative livelihoods, and are mostly already threatened. We thus sought to quantify the potential conflict between key economic activities (5 fisheries and hydrocarbon exploitation) and sea turtle migration corridors in a region with rapid economic development: southern and eastern Africa. We satellite tracked the movement of 20 loggerhead (Caretta caretta) and 14 leatherback (Dermochelys coriacea) turtles during their postnesting migrations. We used movement‐based kernel density estimation to identify migration corridors for each species. We overlaid these corridors on maps of the distribution and intensity of economic activities, quantified the extent of overlap and threat posed by each activity on each species, and compared the effects of activities. These results were compared with annual bycatch rates in the respective fisheries. Both species’ 3 corridors overlapped most with longline fishing, but the effect was worse for leatherbacks: their bycatch rates of approximately 1500/year were substantial relative to the regional population size of <100 nesting females/annum. This bycatch rate is likely slowing population growth. Artisanal fisheries may be of greater concern for loggerheads than for leatherbacks, but the population appears to be withstanding the high bycatch rates because it is increasing exponentially. The hydrocarbon industry currently has a moderately low impact on both species, but mining in key areas (e.g., Southern Mozambique) may undermine >50 years of conservation, potentially affecting >80% of loggerheads, 33% of the (critically endangered) leatherbacks, and their nesting beaches. We support establishing blue economies (i.e., generating wealth from the ocean), but oceans need to be carefully zoned and responsibly managed in both space and time to achieve economic (resource extraction), ecological (conservation, maintenance of processes), and social (maintenance of alternative livelihood opportunities, alleviate poverty) objectives.     

砷在海洋食物链中的生物放大潜力及发生机制探讨

砷是世界范围内危害最大的环境污染物之一,也是近海区域一种常见污染物。本文综述了近年来砷在海洋生态系统中累积、转化及传递的最新研究进展。海洋生物普遍具有较高含量的砷,这些砷主要为低毒性的有机砷形态。砷在许多海洋食物链/网中被生物放大,造成高营养级生物中的砷富集,可对生物与人类健康产生潜在危害;这与砷在淡水食物链/网中普遍被生物减小的现象形成鲜明对比。海洋鱼类和贝类等生物可将吸收的无机砷通过生物转化合成砷甜菜碱等有机砷形态,而有机砷比无机砷具有更高的食物链传递能力,可导致海洋鱼类富集更高浓度的砷。因此,砷在海洋生物中的有机形态可能有助于砷沿着海洋食物链/网富集,在某些情况下被生物放大。今后应该加强对不同砷形态在海洋食物链/网中传递及相应影响因素的研究,并通过室内模拟实验与野外调查相结合进行验证,从而加深对砷的生态毒理和生物地球化学作用的科学认识,对准确评估预测砷的生态风险和保障海洋生态安全有重要意义。