红树林区底栖动物污染生态学研究进展

综述了底栖动物污染生态学研究的现状。目前有关底栖动物的污染生态学研究主要有以下几个方面：（1）污染物在底栖动物体中含量测定及一些污染物在底栖动物中累积分布的研究。（2）污染物对底栖动物生理特性影响的研究。（3）污染物如城市污水对底栖动物群落的影响研究。（4）底栖动物在水质和底质污染中的监测应用。分别综合和评述了红树林底栖动物污染生态学在重金属、城市污水和有机物污染对红树林区底栖动物的生态效应等方面的研究现状。提出今后红树林区底栖动物污染生态学的研究，应着重生态毒理学和实验生态学的研究。     

A critical review of the potential impacts of marine seismic surveys on fish & invertebrates

Marine seismic surveys produce high intensity, low-frequency impulsive sounds at regular intervals, with most sound produced between 10 and 300 Hz. Offshore seismic surveys have long been considered to be disruptive to fisheries, but there are few ecological studies that target commercially important species, particularly invertebrates. This review aims to summarise scientific studies investigating the impacts of low-frequency sound on marine fish and invertebrates, as well as to critically evaluate how such studies may apply to field populations exposed to seismic operations. We focus on marine seismic surveys due to their associated unique sound properties (i.e. acute, low-frequency, mobile source locations), as well as fish and invertebrates due to the commercial value of many species in these groups. The main challenges of seismic impact research are the translation of laboratory results to field populations over a range of sound exposure scenarios and the lack of sound exposure standardisation which hinders the identification of response thresholds. An integrated multidisciplinary approach to manipulative and in situ studies is the most effective way to establish impact thresholds in the context of realistic exposure levels, but if that is not practical the limitations of each approach must be carefully considered.     

Stationary underwater cameras assess more efficiently clear-water mangrove fish assemblages: A comparison of non-extractive techniques

Research in aquatic ecology requires adequate sampling designs if the underlying processes that govern population and community dynamics are to be understood. Adequate sampling design is particularly important for organisms inhabiting environments such as mangroves. Thus, collecting quantitative ecological data remains a major challenge. Here, we analysed the structural and temporal dynamics of a tidal cycle and mangrove fish assemblages at 15 sites along the Brazilian central coast. Specifically, we used two non-extractive sampling techniques, which included stationary underwater visual census (s-UVC) and stationary underwater wide-camera census (s-UWC). Our results showed that by reducing potential observer effects, the s-UWC protocol maximized fish counts, yielding more accurate and precise estimates. In contrast, although the s-UVC technique was a useful approach, this technique did not yield precise density and richness estimates. Furthermore, the negative effect associated with the presence of an observer (i.e., diver) was a significant constraint to the observer-based technique. Furthermore, the methods were more similar for the high tide samples and more divergent for the flood tide and ebb tide samples. These pronounced divergences among tidal periods allowed the application of a temporal mixed-sampling protocol (i.e., unbalanced temporal samples) based on s-UWC without the loss of statistical power. Methodological gains also were felt with a reduction in the costs associated with the presence of a trained observer in water and overcoming of constraints positively related to depth limitations. Overall, the s-UWC protocol adequately captures species using different stages of the tide to enter the mangroves.     

An endemic brachiopod fauna from the Middle Ordovician of North Wales

The brachiopod fauna from the base of the Bryn Siltstone Formation (middle Caradoc), Glyn Ceiriog, north Berwyn Hills, North Wales, consists of Platystrophia elevata sp. nov., Salopia abbreviata sp. nov., Kiaeromena ungula (M'Coy) and unnamed species of Hesperorthis?, Reuschella and Bicuspina. The dominant brachiopod species, Leptaena (Leptagonia) ungula M'Coy, 1851 is revised and its current assignment to the leptaenid genus Kiaeromena confirmed, based on the examination of type and topotype material from the Bryn Siltstone Formation. Kiaeromena spjeldnaesi nom. nov. is proposed to replace the junior homonym K. ungula Spjeldnæs, 1957 for that congeneric species from the upper Caradoc rocks of Ringerike, southern Norway. The fauna as a whole is unusual within the context of the Anglo-Welsh province and may represent a rare preserved nearshore community.     

太湖鱼类区系变化和渔获物分析

20世纪80年代之前,太湖有鱼类107种、25科,属4个生态类型:洄游型、江湖洄游型、河流型和湖沼型.自2002年9月至2006年1月进行了太湖鱼类采集,共采得鱼类60种、18科.其中,除放流的鱼类外,都能在封闭的湖泊环境中完成生命周期(湖沼生态型);团头鲂、鲮、银鲫和尼罗罗非鱼属移植种类.团头鲂、鳙、鲢、草鱼和青鱼是从20世纪60年代起每年向湖中放流的鱼类;鳗鲡则是自1976年起放流从长江采捕的鳗苗.20世纪50年末至1985年,长江和太湖之间人为隔断,不能在静水中繁殖的鱼类在湖中消失,自然鱼类资源下降;加上过度捕捞和对繁殖群体缺少保护,导致鱼类群体小型化.最后,对太湖渔业资源的优化进行了讨论,并进一步提出对策.     

Dispersant Use and a Bioremediation Strategy as Alternate Means of Reducing Impacts of Large Oil Spills on Mangroves: The Gladstone Field Trials

Over a three-year period (1995–1998), we studied short-term effects of dispersant use and a bioremediation strategy in two consecutive field trials in sub-tropical Australian mangroves. In each case, weathered oil was applied, and a large spill simulated, in mature Rhizophora stylosa trees around 4–9 m tall. In the first trial, we used Gippsland light crude oil with or without dispersant, Corexit 9527. In the second, a bioremediation strategy followed application of Gippsland oil or Bunker C fuel oil. Bioremediation involved forced aeration with supplemental application of nutrients. Dispersant use had an overall positive benefit shown as reduced tree mortality. By contrast, there was no apparent reduction in mortality of trees with bioremediation. However, one year after oiling, leaf densities of surviving trees were greater in bioremediation plots than in controls, and less in oil-only plots. These and other results have been incorporated into spill response management strategies in Australia.     

Fish fauna recovery in a newly re-flooded Mediterranean coastal lagoon

Drana Lagoon, located at the NW site of Evros River Delta, was drained in 1987 and re-flooded in 2004 within the framework of an integrated wetland restoration project. This study presents the results of a monitoring program of the lagoon's oceanographic, water quality and fish fauna characteristics, during the pre- and post-restoration period. Results depict the presence of high salinity water (up to 41) due to seawater intrusion, strong evaporation in its interior and inadequate freshwater inflows. Overall, nutrient levels were low depicting local changes. Tidal variability at the mouth was approximately 0.2 m, producing high velocity tidal currents (up to 0.75 m/s). Eleven fish fauna species were collected; seven species were caught in both the inlet channel and the lagoon during the pre-restoration period and nine species in the post-restoration period. Atherina boyeri (37.6%) and Pomatoschistus marmoratus (31.7%) dominated the lagoon during the post-restoration period. Most of the A. boyeri specimens (88.5%) were caught inside the lagoon, while P. marmoratus had an almost equal distribution in the inlet channel and the lagoon (56.3% and 43.7% respectively). The presence of species of the Mugilidae family (5.2% total average catches after lagoon re-flooding) was mainly in the inlet channel (12.6% of the average catches) and not inside the lagoon (only 1.3% of the average catches). The small number of fish species inhabiting the lagoon might be the result of the recent restoration or it could be related with the increased water flow observed at the lagoon mouth during the flood and ebb tidal phases, and also in the presence of a smooth bank in the concrete waterspout that connects the entrance channel with the lagoon. The limited presence of the Mugilidae juveniles inside the lagoon could be related to the prevailing tidal inlet dynamics (i.e. strong ebb flow at lagoon inlet), thus preventing the species to enter the lagoon. In order to restore the lagoon environment, careful and gradual steps should be undertaken under the basis of continuous monitoring of hydrologic, environmental and fisheries system's status.     

Vertical migrations of the mangrove snail Cerithidea decollata (L.) (Potamididae) through a synodic month

The vertical migration on mangrove trunks of the gastropod Cerithidea decollata was followed for 5 weeks, in a Kenyan mangrove. Most of the times, snails forage on the mud surface, during low tide, and climb back on trees well before the incoming tide. As soon as the sea retreats, the downward migration takes place and the snails spread again on the ground. The migratory behaviour of snails can vary widely, depending on the relative tide intensity, and different strategies can be exhibited. Individuals can spend several days on trees without migrating to the ground, around Spring Tides, or else, they might remain on the ground without bothering to migrate upwards, during Neap Tides, when the study area is not reached by the water. These irregular animal behaviours, relating to the complicated tide succession, can hardly be explained by the sole presence of an internal clock, and direct cues seem necessary to switch between different strategies, tuning the snails migratory behaviour to the actual local sea conditions.     

中国陆相上新统麻则沟阶

年代地层单位麻则沟阶是中国上新统的两个阶之一,代表陆相上上新统,1999年由第二届全国地层委员会正式命名,对应于麻则沟期。"麻则沟"一名源自同名岩石地层单位麻则沟组,典型剖面位于山西省榆社县云簇镇赵庄—大马岚。麻则沟阶对应于"国际地层表"中的皮亚琴察阶,其共同的底界定义为古地磁Chron C2An.3n的底,即高斯正极性带的底,绝对年龄为3.6 Ma,这条界线在榆社赵庄剖面位于第6层麻则沟组下部的紫红色黏土层的中部,以张洼沟姬鼠(Apodemus zhangwagouensis)的首现为标志。麻则沟期与欧洲陆生哺乳动物分期的Villa-nyian早期或Villafranchian早期相当,包含1个哺乳动物群单位,即NMU13,可与欧洲的MN16对比。在榆社盆地发现的麻则沟动物群就相当于NMU13。在中国的上新世哺乳动物群中,甘肃灵台的任家沟动物群和雷家河V带动物群、河北阳原泥河湾的稻地动物群、陕西渭南的游河动物群、山西静乐的贺丰动物群、四川德格的汪布顶动物群也相当于NMU13。河北泥河湾的花豹沟剖面是麻则沟阶的辅助层型剖面。     

海水表面温度变化及其对笔石动物群分布的控制作用——以湖北宜昌奥陶系大湾组为例

本文通过对宜昌黄花场剖面和宜昌陈家河剖面大湾组83件样品和陈家河剖面红花园组2件样品的碳氧同位素测试数据,分析了奥陶纪大坪期海水表面温度的变化;并以宜昌黄花场剖面大湾组笔石序列为基础,结合华南地区笔石动物群的分布情况,分析了海水表面温度的变化对笔石动物群地理分布的影响,提出温度变化仅是影响笔石动物群地理分布的间接因素,前人的纬度分带学说值得进一步探讨。