Studies on marine nanodiatoms in Fujian coastal waters of China in winter

For the first time, nanodiatoms (<20μm) and microdiatoms (>20μm) in the coastal waters of Xiamen, Shandu, Fuqing, Haitan, Putian and Meizhou of Fujian Province along the western coast of the Taiwan Strait are quantitatively counted by TEM in the paper. The results show that the number of nanodiatoms from all the station is more than that of microdiatoms, accounting for 92% of the species collected. This indicates that nanodiatoms constitute a large microcosm of the whole diatom group. Unfortunately, the lower resolution of light microscopes which have been used in the study of diatoms in the past makes this unneglectable microcosm unnoticed. Thanks to TEM, 47 species of nanodiatoms are identified and four of them are for the first time recorded in China. The new records are Hantzschia spectabilis, Navicula crucigera, Nav. spicula andNitzs. rosenstockii. The positive correlation between the contents of chlorophyll a and diatom cell number in the waters of Xiamen Harbour, which were determined simultaneously, shows that the variation of chlorophyll a content in the waters reflects, on the whole, the change of diatom number. In addition, the successful culture of nanodiatoms in the studies provides alternatives for the screening of high quality aquaculture feed.

A new species of Cymbasoma Thompson, 1888(Copepoda: Monstrilloida) from the Fujian coast, China

A new monstrilloid copepod species, Cymbasoma cheni sp. nov., from Meizhou Bay (an embayment in Fujian Province, southeastern China) is described and illustrated. The diagnostic character of the new species is the structure and armature of the fi fth leg, which is represented by a single lobe armed with three naked setae subequal in length. The new species closely resembles Cymbasoma bowmani Suárez- Morales and Gasca, 1998 in the structure of the fi fth legs, and the body proportions, including total body length, and relative lengths of the cephalothorax and the genital double somite. However, Cymbasoma cheni sp. nov. is distinguished by lack of cuticular ornamentation on the cephalothorax, the position of the oral papilla, and the structure of the fi fth leg with three naked setae. Although the structure of the fi fth legs is similar in Cymbasoma cheni sp. nov. and Cymbasoma quintanarooense (Suárez-Morales, 1994), the new species can be easily distinguished from Cymbasoma quintanarooense by the relative length of the antennule, diff erences in the genital double-somite and the ovigerous spines, and the shape of ocelli. This is the sixth record of this genus from China seas.

Study on in-situ stress measurement around coastal marginal land in Fujian

The in-situ hydraulic fracturing stress measurements have been carried out around the coastal marginal land in Fu- jian Province. And the characteristics of magnitude, direction and distribution of tectonic stress have been obtained. Based on the observed stress data, the characteristics and activities of fault zones are analyzed and studied in the paper according to the Coulomb friction criteria. 1 The maximum horizontal principal compressive stress is in the NW-WNW direction from the north to the south along the coastline verge, which is parallel to the strike of the NW-trending fault zone, consistent with the direction of principal compressive stress obtained from geological structure and across-fault deformation data, and different from that reflected by focal mechanism solution by about 20°. 2 The horizontal principal stress increases with depth, the relation among three stresses is SH>Sv>Sh or SH≈Sv>Sh, and the stress state is liable to normal fault and strike-slip fault activities. 3 According to Coulomb friction criteria and taking the friction strength μ as 0.6~1.0 for analysis, the stress state reaching or exceeding the threshold for normal-fault frictional sliding near the fault implies that the current tectonic activity in the measuring area is mainly normal faulting. 4 The force source of current tectonic stress field comes mainly from the westward and northwestward horizontal extrusions from the Pacific and Philippine Plates respectively to the Eurasian Plate.

Research on Micro-relief of Active Faults on the Coast of Southeast Fujian and Its Adjacent Area

On the southeast coast of Fujian and its adjacent area, the NE-trending Changle-Zhao＇an fault zone and several NW-trending faults that are genetically related to the former are well developed. With micro-relief analysis, the paper deals with the Quaternary activity of the faults and the tectonic stress field since the late Pleistocene in this region. The results indicate that the micro-relief of the NE-trending Changle-Zhao＇an fault zone and the genetically related NW-trending faults is characterized by vertical and horizontal movements since the Quaternary; the faults in the region have undergone two active stages since the Quaternary, i.e. early Quaternary and late Pleistocene; since the late Pleistocene, the movement of the NE- trending faults showed a right-lateral strike-slip, while that of NW-trending faults a left-lateral strike-slip, indicating a NWW-SEE oriented horizontal principal stress of the regional tectonic stress field.

Studies on island intertidal benthic ecology in Fujian

A total of 862 benthic species were identified in the island intertidal zone in Fujian, of which 734 species are animals and 128 species algae. Determination of Jaccard's similarity index of species was made on the intertidal communities around 11 major islands. Based on hierarchical clustering (WPGMA) and polar ordination, the benthic communities may be classified into three types; the estu-arine type, the bay and harbour type and open sea type. The distribution of the benthic community is related to the location of the island and its habitats of which, salinity and hydrodynamics are the major factors controlling the distribution of the communities.

Three Australian leg-flagged Roseate Terns found at Caiyu Archipelago of SE Fujian, China

In undertaking regular surveys on those waterbirds appearing on Fujian coast and on offshore islands,people of Xiamen Bird-watching Society had observed,for five times during 2007-2009,three marked individuals of the Roseate Tern (Sterna dougallii) on Caiyu Archipelago of south Fujian offshore; it is now quite certain that the leg-flags were marked on birds by people of the Australasian Wader Studies Group (AWSG) and at least one of those leg-flagged terns is already over six or seven years old by the time of re-sighting; this record might be useful and helpful for further estimating the life circle as well as the length of generation of those gulls and terns appearing and breeding along the SE Chinese coast,such as the Black-tailed Gull (Larus crassirostris),the Great Crested Tern (Sterna bergii),the Chinese Crested Tern (S.bernsteini),etc.

Tectono-Sedimentary History of Southeastern Coast Region,China:a Synthesis

According to the ideas and concepts of systems dynamic of continent structure, using previous information related to the study area, combining analyses on orogenic belt, basin and magmatic rock, the present paper synthesizes the tectono - sedimentary development of southeastern coast region, China, with special emphasis on the mountain making, basining and magmatic activity. The tectonic evolution after Late Caledonian orogeny was dominated by alternating rifting and converging, subsiding and uplifting, mountain making and basining in central and southern parts of southeastern China and the adjacent regions to the east and west. Seventeen geologic events , nine events of plate or terrain convergence , and continental crust accretion , as well as eight events of intracontinental rifting and basin faulting , are closely related to the tectonic and sedimentary evolution of the study area . The accompanied intense and frequent sedimentation , folding , faulting , magmatism and ore- forming process allowed huge coal , multimetal and potential petroleum source rocks to form in local depressions throughout the Caledonian to Himalavan time .

CHIME AGES OF CRETACEOUS GNEISSIC GRANITOIDS IN THEPINGTAN-DONGSHAN BELT,FUJIAN, CHINA

A method of isotopic age determination. CHIME (chemical Th-U-total Pb isochron method) for dating radioactive minerals, is introduced briefly in this paper. The monazite. xenotime and zircon from the gneissic granitoids in the Pingtan-Dengshan belt, Fujian. yield CHIME ages of 92. 7 Ma. 94. 4 Ma. 107. 1 Ma and 108. 2 Ma. reconfirming the Yanshanian granitism in southeast coast area of China.

福建长乐海域水沙环境及海岸演变研究

依托实测水下地形和水文泥沙资料,研究了福建长乐海域水沙环境及海床冲淤演变特征。研究结果表明:福建长乐海域为基岩岬角控制的沙质海岸,波浪较强、潮流流速小、水体含沙量低、海岸线及海床地形长期保持基本稳定状态;研究海域的常风向和常浪向均为NNE向,强风和强浪主要受台风及寒潮大风影响;研究海域属强潮海区,最大潮差为6.92 m,平均潮差为4.45 m;研究海域潮流属正规半日潮流,往复流特征明显;研究海域底质分布在横向上呈现近岸粗、深水区细的分布特点,近岸存在南北连续的砂质沉积带,波浪作用下自北向南输移的泥沙对海岸演变有一定影响。

台风“莫拉克”(2009)对浙闽沿岸泥质中心沉积有机质组成与分布的影响

台风是天气尺度上对海洋环境影响最大的海气相互作用过程之一,在短时间内会对影响海域的海洋环境(包括沉积有机质等)产生巨大的影响。本文基于夏季台风前、后采集的浙闽沿岸泥质中心沉积物的粒度、总有机碳(TOC)、总氮(TN)以及碳同位素组成(δ^(13)C)的测试结果,分析了台风“莫拉克”(2009)对研究区沉积有机质来源及分布的影响,对比了台风“莫拉克”与其他不同路径的台风对沉积有机质分布影响的差异,探讨了影响差异的机制。结果显示,台风“莫拉克”(2009)对浙闽沿岸泥质区沉积物中TOC的来源和分布产生了显著影响。端元分析结果表明,浙闽沿岸泥质中心沉积物中有机碳主要来源于长江三角洲沉积物以及海洋自生有机质,在台风的影响下,浙闽沿岸泥质中心的初级生产力升高,进而增加了沉积物中海源有机碳的比例。同时,在台风的动力作用下,近岸沉积物发生了明显的侵蚀与再搬运,导致近岸沉积物中TOC的含量显著降低。受控于台风不对称风场造成的沉积动力差异,不同路径的台风会对研究区的物源输入、海洋生物地球化学以及沉积物的搬运改造等产生不同的影响,进而影响到沉积有机质的组成和分布。研究结果为全面认识极端海况影响下近岸陆架“碳埋藏”提供了科学依据。

闽南沿海雾滴谱统计特征及其与能见度的关系

利用2019~2021年厦门市翔安区气象局观测的雾滴谱资料,分析了闽南沿海雾的微物理参数及滴谱特征,研究了能见度与粒子数浓度、液态水含量、相对湿度等的关系。在此基础上对能见度进行分级参数化拟合与检验评估。结果表明闽南沿海雾的平均粒子数浓度为47.5 cm^(-3),平均液态水含量为0.0763 g m^(-3)。当能见度下降时,粒子数浓度、液态水含量快速上升,平均直径、有效直径等物理量缓慢上升。能见度低于100 m时,平均粒子数浓度达到115.42 cm^(-3),液态水含量达到0.228 g m^(-3)。粒子数浓度和液态水含量谱线均呈现双峰结构特征分布,粒子数浓度主峰的粒子直径范围为4~6μm,次峰值为22~26μm。液态水含量与粒子数浓度相反,主峰位于24~26μm,次峰为4~6μm,表明雾的粒子数浓度主要受小粒子控制,但液态水含量以20~30μm段的粒子贡献最为显著。与沿海地区相比,闽南沿海雾的平均粒子数浓度小于华南沿海,高于华东沿海;平均液态水含量高于华南沿海,低于华东沿海。与内陆城市区域或县郊相比,同等状态下沿海的粒子数浓度明显更低,但液态水含量更大。采用四种参数化方案对能见度进行了分段以及不分段拟合。评估检验结果表明,采用粒子数浓度和液态水含量的乘积作为因子的分段拟合效果最优,尤其是对于1 km以下的能见度拟合效果更优。

海地瓜聚集行为对核电厂冷源的风险分析

福建北部海域5月中下旬,海地瓜亲体进入繁殖季节高峰期;6月中旬小型海地瓜在沉积物浅表层生存,9月中旬前受台风搅动可再悬浮进入水体。海地瓜繁殖能力强,在幼体浮游阶段和小型海地瓜再悬浮阶段两次区域再分配以及核电厂取水作用下,可在核电厂取水口海域形成海地瓜高聚集区;伴随着海地瓜指数性增长,可在7—9月形成大量的致灾小型海地瓜,在台风等作用下悬浮进入水体,在取水作用下聚集于鼓网并致灾。因此在海地瓜适宜生长环境建设核电厂,应开展海地瓜聚集风险评估与防控措施。

WRF、EC和T639模式在福建沿海冬半年大风预报中的检验与应用

基于福建省冬半年沿海和港湾岛屿自动站的逐时极大风观测资料和WRF（Weather Research and Forecast）、EC（European Centre for Medium-Range Weather Forecasts）细网格以及T639（TL639L60）三种模式预报的10 m风场资料，将模式预报的风向风速与观测资料进行对比检验，结果表明：福建省沿海冬半年大风的盛行风向以东北风为主，大风的时空分布极为不均，沿海风力的脉动性、跳跃性、局地性突出。从三种模式对风速风向的模拟效果来看， WRF和EC细网格的预报效果较好，有可参考性， T639可参考性不高。对于风速，模式预报结果相比实况极大风速偏小，港湾岛屿代表站风速的平均绝对误差均小于沿海代表站，预报平均误差由沿海向内陆逐渐减小，由中部向南北逐渐减小。风向相比风速的预报效果要差， WRF和EC细网格的风向预报误差在45°-50°，有一定的参考意义；港湾岛屿代表站风向的平均绝对误差大于沿海代表站，以浮标站的误差最大。当观测风速出现7级及以上风速时，若对大风进行分级检验，则较低风速的预报平均绝对误差小于较高风速；风向预报的平均绝对误差也大大降低，且误差都在45°以内，具有良好的参考性。

热带气旋影响福建沿海风暴潮特征分析

文中利用1990-2008年气象要素资料、热带气旋路径资料和福建沿海9个验潮站资料，从热带气旋登陆、路径以及福建沿海地理特征等方面，分析研究福建沿海热带气旋风暴潮特征。结果表明：每年平均约有5.58个热带气旋登陆或影响福建，风暴潮发生率为81.1%，福建沿海风暴潮主要出现在5-10月，风暴潮过程最多的是8-9月，平均每年有4.53次风暴潮过程。正面登陆福建的热带气旋和登陆浙南的影响热带气旋，最容易引发福建省沿海热带气旋风暴潮过程，且风暴增水最强，最大增水可达200cm以上，其次是登陆广东的影响热带气旋。由于闽江口的喇叭口地形作用，位于闽江入海处的闽江口岸段在全省4个岸段中风暴增水最强。

福建沿海晚更新世以来的海平面变化

本文选择了六类79个具有14C年龄和准确高程的古海面标志物，按北、中、南三个岸段分别建立了三条相对海平面变化曲线，讨论了福建沿海晚更新世以来的海平面变化特征和规律。通过比较也分析了不同岸段的新构造差异升降情况。

福建沿海风暴潮特征的分析

通过普查 1960—2001年正面登陆我国东南沿海的台风,分析了福建沿海风暴潮的特征及其可能原因。台湾海峡特殊地形对福建沿海风暴潮的时空分布有明显影响,登陆岸段不同,台湾海峡对风暴潮的影响作用也不同,导致福建沿海风暴潮出现明显不同的分布和变化特征。当台风位于台湾海峡时,其大风区位置和范围不同,会影响福建沿海各地风暴增水的幅度。台风横穿台湾海峡时,易使福建沿海台风大风区中心岸段出现双增水峰现象,第一个增水峰出现在台风离开台湾岛进入台湾海峡后,第二个增水峰出现在台风登陆福建沿海前后。台风横穿台湾海峡有时会引起台湾海峡北部出现奇异增水现象,风暴潮与天文潮之间的相互作用可能是其重要原因。奇异增水峰往往出现在天文潮低潮附近,此时实际潮位并不高。

福建省海水贝类养殖区表层沉积物及贝类滴滴涕的残留与风险评价

为了评估福建省海水贝类养殖区滴滴涕(DDTs)的残留水平和风险,于2005年8月和2006年8月,采集养殖区20个站位的表层沉积物样品20个、养殖贝类样品46个,用气相色谱法测定其中DDTs的残留量,并对其残留水平、分布趋势和组成特征进行分析,以期对该地区污染状况、生态风险及贝类食用安全进行探讨与评价。结果表明,福建省贝类养殖区表层沉积物DDTs含量范围为1.93～56.6μg/kg(干重),平均值15.8μg/kg;40%的样品DDTs的污染指数在0.697～2.83之间,不同程度受到DDTs的污染,提示存在一定的潜在生态风险。养殖贝类DDTs含量范围为2.04～107μg/kg(湿重),平均21.7μg/kg;贝体DDT残留量符合中国无公害水产品质量安全标准,低于欧盟、美国、日本的食品安全限量;以每人50 g/d的摄食量估算,沿海居民食用养殖贝类的DDTs暴露量远低于WHO暂定的TDI值、美国EPA推荐的RfD值,由此引起的健康风险小。与国内邻近海域相比较,福建省贝类养殖区表层沉积物和养殖贝类体中DDTs残留量处于中等水平,与亚太等国外海域相比较,处于较高水平;从DDTs的组成特征推测,调查区部分海域有新的DDTs污染源输入。

福建沿岸海滩—沙丘系统地貌变化特征及关系模式

通过2007年7月至2010年2月对福建沿岸25个主要沙丘岸段的调查,以及代表性海滩-沙丘地貌系统地形变化的重复观测,针对福建海岸海滩类型和前缘沙丘地貌组合,从海滩动力地貌特征、沙丘形态及其变化角度出发,分析了海滩-沙丘地貌体系的变化特征,并进一步探索海滩动力地貌与沙丘地貌及其变化之间的关系模式。结果为:(1)福建沿岸海滩-沙丘系统的地貌变化可以归纳为3种类型:①海滩稳定-沙丘变化型;②海滩侵蚀-沙丘稳定型;③海滩侵蚀-沙丘后退型。(2)福建沿岸海滩-沙丘系统的动力地貌关系可以归纳为6种基本模式,主要表现为完全耗散型、过渡型和低潮阶地型3种海滩地貌与沙丘规模和形态的对应关系,海滩的沉积状态与海滩-沙丘系统内部的相互作用,也在某种程度上决定了其动力地貌关系模式。

2012年福建沿海大规模米氏凯伦藻赤潮暴发的水文气象原因探讨

本文利用ERA-Interim资料集、HYCOM全球再分析资料以及沿海各站点数据,通过分析比较2005、2011和2012年福建沿海春季(3—5月)气温、水温、风场、流场和降雨数据,探讨了2012年春季水文、气象要素的年际变化特征及其与米氏凯伦藻暴发的关系。结果表明:2012年春季暴发的大规模米氏凯伦藻赤潮极可能与初春水温偏低,晚春水温偏高,后期海水迅速升温有关:初春(3月)沿海水温偏低,抑制了东海原甲藻的前期孕育;晚春(5月)水温偏高,有利于各种藻类,特别是偏暖暴发的米氏凯伦藻的生长;3—5月海水过快的升温过程,使得米氏凯伦藻成为优势藻种。相对于气候态平均而言,2012年5月呈强北风特性,水体向岸堆积作用明显,有利于藻类在近岸的堆积聚集和种群密度的提高,为藻类的生长提供了稳定的动力环境,促进了赤潮的暴发。此外,2012年1—4月的大降雨量可能为米氏凯伦藻的生长提供了良好的生物化学环境。

2001-2020年福建沿海赤潮灾害分级和时空分布特征研究

利用2001-2020年福建沿海赤潮事件记录资料和自然灾害风险判定方法,根据赤潮成灾面积、持续时间、危害类型、渔业直接经济损失等指标综合计算赤潮灾害指数。基于自然断点法,对赤潮灾害指数进行Ⅰ级、Ⅱ级、Ⅲ级、Ⅳ级等4个灾害级别分等定级。系统分析了福建沿海赤潮生物种类、时空分布特征和演变规律。结果表明:(1)2001-2020年福建沿海赤潮以灾害程度较轻的Ⅰ级和Ⅱ级为主,灾害程度较重的Ⅲ级和Ⅳ级仅占总次数的8.9%,但其造成的渔业直接经济损失达总损失的95.0%。(2)赤潮暴发次数和面积总体呈现下降趋势,但Ⅲ级和Ⅳ级灾害频次呈现波动特征。(3)季节尺度上表现为单波峰特征,5-6月是赤潮灾害最为严重的时段,赤潮暴发次数、面积和持续时间占总体的比例分别为73.3%、84.6%和74.9%,Ⅲ级和Ⅳ级灾害占总次数的95.2%。(4)空间尺度上,福州、宁德、厦门沿海赤潮累计次数和规模较大,但Ⅲ级和Ⅳ级赤潮灾害主要分布在泉州以北的福建沿海,泉州以南的福建海域赤潮灾害级别整体较低。(5)2001-2020年福建沿海赤潮原因种逐渐增多,硅藻占比减小、甲藻占比升高,有毒赤潮主要出现在宁德、福州、泉州海域,以米氏凯伦藻(Karenia mikimotoi)引发居多。(6)硅藻赤潮主要暴发在峡湾和海湾海域,而甲藻赤潮在峡湾、海湾和开阔的近岸海域均易暴发,近年来甲藻赤潮暴发位置呈现由福建北部向南部沿海扩张的趋势。引起这些变化的原因据推测与全球气候变化及福建近岸海域环境的变化密切相关。