台湾岛以东海域束毛藻种群的组成与分布

分别对1996年5月和1997年7月台湾岛以东黑潮及邻近海域51个采样站位的87份网采浮游植物进行了分析,总结了束毛藻种群的物种构成和丰度分布特征,并初步探讨了水动力条件、温盐、营养盐及其他元素对束毛藻生长及分布的影响.结果表明,调查区的束毛藻种群由铁氏束毛藻(Trichodesmium thiebautii)、汉氏束毛藻(Trichodesmium hildebrandtii)和红海束毛藻(Trichodesmium erythraeum)组成,前者分布最为普遍,检出率100%,丰度最大.1996年5月束毛藻平均藻丝体密度为44.55伊102 filaments/m3,铁氏束毛藻占91%,在吕宋海峡密集,总体呈现西南高,东北低的分布态势.1997年7月束毛藻平均藻丝体密度为152.72伊102 filaments/m3,铁氏束毛藻占99%,除吕宋海峡外,台湾东北部海域为次高值区,总体呈现西南高,中部和东部低的分布态势.较之邻近海区结果,台湾岛以东黑潮及邻近海域的束毛藻平均藻丝体密度高于太平洋赤道热带海域、南黄海和东海陆架区、东海产卵场,低于台湾海峡西侧20 m 以浅和东海低氧区.在台湾岛以东海域,束毛藻的丰度分布由其特定的地理位置和黑潮流向所决定,高温高盐的黑潮水系利于束毛藻的增殖,束毛藻的丰度分布与 Fe、P 等化学因子的关系有待进一步寻找证据.     

Tube-forming polychaetes enhance invertebrate diversity and abundance in sandy sediments of Mozambique,Africa

In marine soft-bottom systems, polychaetes can increase habitat complexity by constructing rigid tubes (e.g. several onuphid species) that contrast with surrounding topographically flat sediments. These structures can provide predation refuges and increase larval settlement and thereby increase the richness and abundance of fauna. We collected invertebrate samples from an intertidal flat with low onuphid tube density (2.7 m^–2) in Mozambique and document that more organisms (70 times higher mollusc abundances) and more species (15 times more mollusc species) were found associated with solitary tubes of an onuphid polychaete compared with surrounding sand habitats. These results are in agreement with tube versus sand comparisons from soft-bottom systems in the North Atlantic where polychaete tube densities are often much higher.     

In situ video observations of benthic megafauna and fishes from the deep eastern Mediterranean Sea off Egypt

Remotely operated vehicle (ROV) video observations were used to document benthic fauna at a hydrocarbon drilling location, at 2 720 m depth, in the poorly studied deep water off northern Egypt. The decapod Chaceon mediterraneus was the most common organism at the site and the only benthic megafaunal invertebrate observed. Three species of fish, Coryphaenoides mediterraneus, Cataetyx laticeps and Bathypterois mediterraneus, were also encountered. These findings confirmed these three species as the deepest-distributed benthic fish in the eastern Mediterranean, and confirmed that the deep Mediterranean, in particular the eastern basin, is one of the world's poorest deep-sea ecosystems in terms of diversity. The behaviour exhibited by the species observed was consistent with their natatory capacity, deduced from their feeding intensity (gut fullness) and diet (mainly suprabenthic prey were consumed), and conservative life strategies adapted to an extremely low energy environment.     

Shifts from native to non-indigenous mussels: Enhanced habitat complexity and its effects on faunal assemblages

Ecosystem engineers such as mussels may affect strongly both the structure of benthic assemblages and the ecosystem functioning. The black-pygmy mussel Limnoperna securis is an invasive species that is spreading along the Galician coast (NW Spain). Its current distribution overlaps with the distribution of the commercial native mussel species Mytilus galloprovincialis, but only in the inner part of two southern Galician rias. Here, we analysed the assemblages associated with clumps of the two mussel species and evaluated if the invasive species increased complexity of habitat. To measure complexity of clumps we used a new method modified from the “chain and tape” method. Results showed that the identity of the mussel influenced macrofaunal assemblages, but not meiofauna. L. securis increased the complexity of clumps, and such complexity explained a high percentage of variability of macrofauna. The shift in dominance from M. galloprovincialis to L. securis may alter habitat structure and complexity, affecting the macrofaunal assemblages with unpredictable consequences on trophic web relations.     

日照岚山港北作业区邻近海域春、秋季浮游动物群落结构研究

以2015年5月(春季)和10月(秋季)在日照岚山港北作业区邻近海域进行的浮游动物调查数据为例,分析了该海域浮游动物的群落结构特征。调查海域两季共发现浮游动物成体20种,浮游幼虫7类,其中春季成体12种,浮游幼虫4类,秋季成体19种,浮游幼虫6类;春、秋两季调查浮游动物平均丰度分别为128.1 ind./m³、103.3 ind./m³;平均生物量(湿重)分别为1 129.9 mg/m³、954.3 mg/m³;平均多样性指数分别为2.39、2.01;平均丰富度指数分别为0.85、1.21;平均均匀度指数分别为0.87、0.62;春季调查优势种为强壮箭虫(Sagitta crassa)、中华哲水蚤(Calanus sinicus)、真刺唇角水蚤(Labibocera euchaeta)、太平洋纺锤水蚤(Acartia pacifica)、球型侧腕水母(Pleurobrachia globosa),秋季调查优势种为太平洋纺锤水蚤、小齿海樽(Doliolum denticulatum)、强壮箭虫、真刺唇角水蚤;聚类分析表明,调查海域浮游动物可划分为3个群落。本研究可为深入研究该海域浮游动物群落结构提供重要的基础数据。     

黄河口及邻近海域鱼卵、仔稚鱼群落结构及多样性的年间变化

为了解黄河口及邻近海域鱼卵、仔稚鱼的群落结构动态,分别于2014年、2015年、2017年和2018年的6月利用大型浮游生物网对黄河口及邻近海域进行4个航次的表层水平拖网调查。根据鱼卵、仔稚鱼的种类组成、数量分布等群落结构特征,运用生物多样性指数、聚类分析和皮尔逊相关性矩阵分析等方法对该海域鱼卵、仔稚鱼的资源分布进行了综合研究。结果表明,4年调查共采获鱼卵3 829粒,仔稚鱼234尾,隶属于7目14科15属。鱼卵的主要优势种为鳀（Engraulis japonicus）和短吻红舌鳎（Cynoglossus joyeri）,仔稚鱼的主要优势种为斑鰶（Konosirus punctatus）和虾虎鱼科未定种Gobiidae sp.。生物多样性各指数均以2015年最高,2018年最低。利用R语言对鱼卵、仔稚鱼年间种类组成相似性进行聚类,将4个调查年份划分为3组,各分组之间主要的分歧种均为鳀。生物多样性各指数与环境因子之间皮尔逊相关性分析表明,盐度与鱼卵、仔稚鱼生物多样性的关系较为密切。分析认为,黄河口及邻近海域鱼卵、仔稚鱼群落分布和多样性的年间变化特征体现了鱼类对环境变异的响应。     

Inorganic arsenic speciation in the waters of the Penzé estuary (NW France): Seasonal variations and fluxes to the coastal area

Over this one-year study, the variations of inorganic As species were examined monthly along the salinity gradient of the Penzé estuary (NW France) in relation with different biogeochemical parameters. In most cases, dissolved As exhibited a non-conservative behaviour which resulted from the competition between two major processes. In the upstream section of the estuary, a strong input of both total inorganic As and As(III) occurred. Then, the removal of the same species, under precipitation of iron oxides/oxyhydroxides, was observed in the low-salinity range (S < 10). Using our experimental data, the fluxes of the various As species were estimated for the first time in estuarine waters. Inputs from the river were mainly constituted of particulate As (∼70%). Conversely, dissolved species were predominant in the net fluxes (∼65%) and As(III) accounted for ∼15% of the dissolved net flux.     

东海中南部秋季游泳动物多样性及群落结构

根据2018年11月东海中南部游泳动物底拖网调查数据,对该海域游泳动物种类组成、优势种、种类多样性及群落结构进行研究。结果表明,调查共捕获游泳动物181种,其中鱼类133种,甲壳类34种,头足类14种;优势种（IRI≥500）为七星底灯鱼（Benthosema pterotum）、带鱼（Trichiurus lepturus）、麦氏犀鳕（Bregmaceros mcclellandi）、龙头鱼（Harpadon nehereus）和日本发光鲷（Acropoma japonicum）。多样性指数结果显示,东海中南部海域丰度（d）的变化范围为0.37～5.94,种类多样性指数（H′）的变化范围为0.38～2.64,均匀度（J）的变化范围为0.14～0.71。根据聚类分析结果将东海中南部海域游泳动物群落分为以90 m等深线为界的两个群组,群组间的差异主要由七星底灯鱼、镰鲳（Pampus echinogaster）、龙头鱼、黄鲫（Setipinna tenuifilis）、麦氏犀鳕等引起。BIOENV结果显示水深与游泳动物群落结构相关性最密切（r_w=0.55）。本研究结果可为类似海域游泳动物种类多样性和群落结构的研究提供参考,也可为研究海域渔业资源开发、利用与养护等政策的制定提供科学依据。     

亚洲海域鲎的种类和分布

审核有关亚洲海域鲎种类和分布的历史文献发现,亚洲海域只有圆尾鲎Carcinoscorpius rotundicauda、中国鲎Tachypleus tridentatus和南方鲎Tachypleus gigas3种鲎分布。圆尾鲎分布于中国香港、北部湾、雷州湾以南、印度尼西亚爪哇岛北岸以北、菲律宾南部以西和恒河河口印度东北部以东的海域。中国鲎分布于长江口以南的中国海域、日本濑户内海、九州岛北岸以南、印度尼西亚爪哇岛北岸以北、苏门答腊岛印度洋侧以东和苏拉威西岛以西的海域。南方鲎分布于越南西贡以南、爪哇岛北岸以北、菲律宾南部以西的太平洋海域及印度恒河印度东北部以东的印度洋海域。以前有关中国北部湾海域和香港海域有南方鲎的报道是错误的,把中国鲎的幼体及成体误当成了南方鲎。中国海域只有中国鲎和圆尾鲎2种鲎分布。中国的海南、广西、广东西部和香港(可能还包括台湾)等是圆尾鲎分布的海域。其沿岸要严禁食鲎,以防误食圆尾鲎而引起河豚毒素中毒。