Phylogeography of the shrimp Palaemon floridanus (Crustacea: Caridea: Palaemonidae): a partial test of meta‐population genetic structure in the wider Caribbean

Marine organisms with a pelagic stage are often assumed to display minor population structure given their extended larval development and subsequent high long‐distance dispersal ability. Nonetheless, considerable population structure might still occur in species with high dispersal ability due to current oceanographic and/or historical processes. Specifically, for the wider Caribbean and Gulf of Mexico, theoretical and empirical considerations suggest that populations inhabiting each of the following areas should be genetically distinct: Panama, Belize, Southwest Florida (Tampa), and Southeast Florida (Fort Pierce). This study tests the hypothesis of significant genetic differentiation in Palaemon floridanus populations across the wider Caribbean and Gulf of Mexico. Population level comparisons were conducted using sequences of the mtDNA COI. In agreement with predictions, AMOVA and pairwise F_ST values demonstrated population differentiation among most pairs of the studied populations. Only Panama and East Florida populations were genetically similar. An isolation‐with‐migration population divergence model (implemented in IMA2) indicated that population divergence with incomplete lineage sorting can be invoked as the single mechanism explaining genetic dissimilarity between populations from the east and west coast of Florida. Historical demographic analyses indicated demographic expansion of P. floridanus in some localities [recent in Panama and ancient in East Florida and the wider Caribbean (entire dataset)] but constant population in other localities (in Belize and West Florida). This study rejects the idea of panmixia in marine species with high long‐distance dispersal ability. Contemporary and historical processes might interact in a complex manner to determine current phylogeographic patterns.     

The genus Pseudo-nitzschia (Bacillariophyceae) in New Zealand: analysis of the last decade's monitoring data

The diatom genus Pseudo-nitzschia blooms throughout New Zealand's coastal waters. More than a decade of monitoring data were analysed in this study and seasonality was a significant factor in the appearance of Pseudo-nitzschia blooms. Austral spring and summer were the main bloom periods, although there were regional differences. Between January 2000 and August 2011, 8.4% of 29,000 seawater samples analysed for Pseudo-nitzschia exceeded the voluntary trigger level for biotoxin testing (10×10⁴ cells l^?1), and these were analysed by fluorescent in situ hybridisation (FISH) assays. Pseudo-nitzschia fraudulenta and P. pseudodelicatissima (low domoic acid [DA] producers) were the dominant bloom formers throughout New Zealand (each contributing 25%) followed by the highly toxic P. australis (10%). Shellfish flesh testing for DA was triggered on 8477 occasions between 2000 and 2011, but no samples exceeded the regulatory limit (20 mg/kg); the maximum concentration was 13 mg/kg (Marlborough Sounds, mid-winter 2010).     

杭州湾海域50年一遇波浪数值模拟研究

杭州湾外围海域岛礁众多,波浪传播机制复杂。为了了解该海域的波浪分布特征,采用MIKE 21 SW模块建立了杭州湾海域波浪数值模型,利用实测波浪资料对模型进行了验证,结果表明该模型适用于模拟杭州湾海域的波浪传播。利用1970—2002年嵊山海洋站实测极值波浪资料推算50年一遇波浪要素,将其作为模型边界条件,对杭州湾海域50年一遇的设计波浪进行了模拟,并对该海域的波浪传播特征进行了分析。结果表明,杭州湾内波高较之外海明显减小,外围众多岛礁起到了很好的遮挡保护作用。     

响应面法优化南极菌Psychrobacter sp.B-3的发酵产糖条件

为对南极菌Psychrobacter sp.B-3产胞外糖的发酵条件进行优化,以温度、pH、不同碳源、不同氮源、不同金属离子及海水配比作为唯一变量进行单因素实验,筛选出对产糖有显著影响的单因素取值范围;在此基础上,利用Plackett-Burman实验设计筛选出影响产多糖的3个主要因素,即酵母粉、陈海水配比和装液量.然后通过Box-Behnken实验设计及响应面分析法进行回归分析,得出了南极菌Psychrobacter sp.B-3发酵条件系统优化的结果为:酵母粉1.1 g/L,陈海水与自来水的配比为2:1,装液量为50％,蛋白胨6.0 g/L,接种量1.5％,培养时间64 h,BaCl20.03 g/L,温度10℃,转速150 r/min,pH为7.0.优化后发酵液中的糖含量由优化前的444 μg/mL提高到624 μg/mL,相比初始糖产量提高了40％.结果表明,响应面法可显著优化南极菌Psychrobacter sp.B-3液体发酵产胞外糖的条件.     

长江口及其邻近陆架区夏季网采浮游植物及其影响因素

2009年6、8月长江口及其邻近陆架区的网采样品中检出浮游植物9门395种(含223种硅藻与125种甲藻)。浮游植物丰度8月(3 077.15×104 cells/m3)显著高于6月(107.80×104 cells/m3)。随长江冲淡水势力增强,位于长江口的丰度高值区8月较6月更偏外侧。种类丰富度8月高于6月,但多样性和均匀度指数略低于6月。6月尖刺伪菱形藻和三角角藻占绝对优势,8月优势种主要有尖刺伪菱形藻、笔尖形根管藻和铁氏束毛藻。骨条藻虽非优势种,但在长江冲淡水区丰度较高。相似性分析和多维尺度分析表明,浮游植物群落组成时空差异显著。典范对应分析表明,温度和盐度是分别影响6、8月群落分布的首要因子。根据水动力和化学参数,该区浮游植物群落分布与环流变化和水团消长密切相关。     

Assessing the benthic quality status of the Bohai Bay (China) with proposed modifications of M-AMBI

Multivariate AZTI's Marine Biotic Index (M-AMBI) was designed to indicate the ecological status of European coastal areas. Based upon samples collected from 2009 to 2012 in the Bohai Bay, we have tested the response of variations of M-AMBI, using biomass (M-BAMBI) in the calculations, with different transformations of the raw data. The results showed that the ecological quality of most areas in the study indicated by M-AMBI was from moderate to bad status with the worse status in the coastal areas, especially around the estuaries, harbors and outfalls, and better status in the offshore areas except the area close to oil platforms or disposal sites. Despite large variations in nature of the input data, all variations of M-AMBI gave similar spatial and temporal distribution patterns of the ecological status within the bay, and showed high correlation between them. The agreement of new ecological status obtained from all M-AMBI variations, which were calculated according to linear regression, was almost perfect. The benthic quality, assessed using different input data, could be related to human pressures in the bay, such as water discharges, land reclamation, dredged sediment and drilling cuts disposal sites. It seems that M-BAMBI were more effective than M-NABMI (M-AMBI calculated using abundance data) in indicating human pressures of the Bay. Finally, indices calculated with more severe transformations, such as presence/absence data, could not indicate the higher density of human pressures in the coastal areas of the north part of our study area, but those calculated using mild transformation (i.e., square root) did.     

近50年来杭州湾七姊八妹列岛海域海床演变分析

七姊八妹列岛海域位于杭州湾南部的灰鳖洋内,除了岛礁周围局部存有深沟外,其余地区海床平缓.为了探究该海域海床演变情况,在了解杭州湾来水来沙特征基础上,分析了七姊八妹列岛海域的水动力、悬沙和底质分布特征.不同时期海图的对比分析表明,该海域近岸水深较小,人类活动频繁,围涂筑堤工程较多,一直处于淤积状态,属淤涨型岸滩,而离岸较远的海域,泥沙难于落淤而随潮反复搬运,基本处于冲淤平衡状态.1962～2008年这46 a间,七姊八妹列岛海域总体呈现与岸线走向一致的淤积、冲刷间隔分布的冲淤带.平均淤积厚度约2.2 m,淤积幅度约5.0 cm/a,大多数地方平均冲刷厚度约2.4 m,冲刷幅度约5.0 cm/a.这些特点与当地的水动力条件和泥沙沉积特性相一致.     

2010年夏、秋季胶州湾浮游动物对表层海水中DMS分布的影响

于2010年7~11月对胶州湾夏、秋季浮游动物种类和丰度进行现场调查,并分析讨论了胶州湾夏、秋季浮游动物丰度的水平分布与环境因子(温度、盐度、水深、叶绿素a)和二甲基硫(DMS)、溶解态β-二甲基巯基丙酸内盐(DMSPd)、颗粒态β-二甲基巯基丙酸内盐(DMSPp)的相关性。结果表明,胶州湾浮游动物丰度分布不均匀,8月湾内西部沿岸海域C1站位出现调查期间的动物丰度最大值(656.1ind/m3),最小值(1.492ind/m3)出现在10月胶州湾东北部的A2站位。浮游动物丰度具有明显的季节变化,秋季浮游动物丰度低于夏季浮游动物丰度。浮游动物丰度与盐度、叶绿素a含量、细菌生物量的相关性不明显,2010年10月浮游动物丰度与DMS呈显著正相关(P0.05),11月的浮游动物丰度与DMSPp呈显著正相关(P0.05),其它月份(7、8、9月)的浮游动物丰度与DMS、DMSPd、DMSPp浓度的相关性均不明显。由于浮游动物摄食活动对DMS释放的影响受多种因素的制约,因此浮游动物与DMS的相互作用需要进一步研究。     

丹江口水库叶绿素a浓度的时空特征及影响因子分析

2017年5月—2019年10月,对"南水北调"中线水源水库——丹江口水库库区水体7个监测位点、0～20 m间4个水层的垂向叶绿素a (Chl.a)浓度与水质因子进行了季度性调查,以期了解不同位点、不同水层Chl.a分布的主要驱动因子.结果表明,丹江口水库各位点营养状态指数(TSI)均为中营养化状态.水体Chl.a浓度具有逐年增加的趋势,且极高值有逐渐增加的趋势.营养盐和Chl.a浓度均存在较大的空间异质性,入库区具有较高的总磷和氨氮浓度,汉江库区具有最高的Chl.a浓度,源头污染源控制和监测仍然是丹江口水库管理的重中之重.不同位点Chl.a浓度的驱动因子存在较大差异,汉江入库和大坝区Chl.a浓度分别受到硝态氮和p H的影响,而出水口大坝位点主要受到了水深、水温和氨氮的影响.丹江入库区Chl.a浓度受到了水深、氨氮、总磷和水温的影响,但丹江库区表现出了与其他生态区较大的区别,其Chl.a浓度主要受到水深和有机质输入的影响.因此,对丹江口水库各位点的管理,应该分不同生态区采取针对性的管理措施.本研究旨在为南水北调中线工程可持续的生态调度提供基础生态数据支持,为完善水库水源地的有效管理提供理论支撑.     

施氏矿物吸附Cu2+及氧化亚铁硫杆菌的实验研究

在金属硫化物的表生氧化过程中,施氏矿物是最常见的一种次生矿物.施氏矿物具有粒度小、比表面积大、表面吸附能高的特点,能够吸附环境流体中的重金属离子和微生物细胞,从而影响重金属元素及微生物的表生地球化学行为.利用化学合成的施氏矿物,开展了施氏矿物吸附Cu2+及氧化亚铁硫杆菌的实验.结果显示:施氏矿物对金属Cu2+及氧化亚铁硫杆菌均有较强的吸附性;施氏矿物对Cu2+的吸附基本符合Langmuir吸附模型,而对氧化亚铁硫的吸附行为不符合Langmuir模型,可用Freundlich模型描述;施氏矿物的存在对流体中微生物的活动性及其地球化学行为有重要影响,可能会降低氧化菌分解金属硫化物的效率.