胶州湾中部海域秋、冬季大型无脊椎动物群落结构及多样性研究

根据2008年9月~2009年2月在胶州湾中部海域进行的逐月定点底拖网调查,对该海域秋、冬季大型无脊椎动物群落结构及多样性变化进行了初步研究.结果表明,胶州湾秋、冬季共捕获大型无脊椎动物60种,其中甲壳动物和软体动物是主要的无脊椎动物类群;优势种组成具有较明显的月间变化,主要为口虾蛄Oratosquilla oratoria、短蛸Octopus ocellatus、脊腹褐虾Crangon affinis等湾内定居性种类及洄游性较小的种类.Margalef种类丰富度指数范围为1.998~4.669,自9月起逐月递减,11月达到最低值,随后又逐月升高,2月达到最高值;Shannon-Wiener多样性指数和Pielou均匀度指数范围分别为1.325~2.500和0.422~0.693,逐月变化趋势与物种丰富度指数基本一致.多样性指数与海域温度、盐度和深度等环境因子均无显著性相关.多元统计分析表明,胶州湾中部海域秋、冬季大型无脊椎动物群落可划分为2个时间组群;组群间群落种类组成结构差异不显著.     

Coenotypes in Submerged Paleoforests in the Qianhu Bay, Fujian Province

The paleoforest remains studied are distributed within a range of 18000 m^2 in the intertidal zone of the Qianhu Bay, Fujian Province. Eighty-nine ancient tree stumps can be clearly recognized in the paleoforest remains. Microscopic studies of 10 relatively low-carbonized stump samples definitely showed four species： Glyptostrobus pensUi （Staunt） Kouch, Schima superba Gardn., Cinnamomum Schaeffer, and Litsea Lam. The 14^C dating of some samples yielded the ages of 42560±350 to 〉43000 a B. P., corresponding to the late Late Pleistocene.     

福建省兴化湾有毒重金属的输入输出

基于对兴化湾大气干、湿沉降,沉积物及河(海)水的取样分析数据,主要考虑河流输入及与外海的物质交换,大气干、湿沉降和沉积作用过程重金属物质的迁移量,估算了兴化湾重金属的输入输出量.结果表明,As、Cr、Pb主要来自于河流输入,其河流输入量分别占总输入量的76.4%,78.2%和68.9%,Hg主要来自于河流输入和与外海的物质交换,Cd主要以大气干、湿沉降为输入方式,该方式的输入量占输入总量的78.8%.沉积作用是5种有毒重金属的主要输出方式,占输出总量的88.2%～100%,潮汐作用可将部分As、Cr、Pb输向外海,但也可能将Hg带入兴化湾,兴化湾Cd污染有加剧的趋势.     

The chronostratigraphy of a quaternary sequence at the distal part of the nile littoral cell,Haifa Bay,Israel

The current detailed chronostratigraphic framework of the last 1 Ma of an eastern Mediterranean sequence (Haifa Bay, Israel) aims to examine the relative roles of sea‐level changes, climate and tectonics. Seven continuous marine cores, up to ～120 m long, were recovered from shallow water depths. The cores were dated by optically stimulated luminescence, ¹⁴C, magnetostratigraphy, ²³⁰Th/²³⁴U, ²⁶Al/¹⁰Be, occurrence of index fossils and correlated to the global sea‐level curve and Marine Isotope Stages (MIS). The sedimentary sequence accumulated during the last ca. 1.0 Ma consists of 21 transgression–regression units with hiatuses between them. Five marine/terrestrial cycles, which occur in the lower part of the sequence, are attributed to the Jaramillo subchron and the Brunhes–Matuyama boundary, and correspond to MIS 29–21. The top ～50 m includes three sedimentary cycles deposited in the last ca. 400 ka. The regressive phases during this interval correspond to Glacial MIS 8, 6 and 2, while the transgressions correspond to Interglacial MIS 11, 7, 5 and 1. Thus, for the first time, this study documents the longest Quaternary succession dated so far in a key area of the Levant, sensitive to global history of sea‐level changes and glacial/interglacial fluctuations. Copyright © 2012 John Wiley & Sons, Ltd.     

Palaeoenvironmental interpretation of Holocene coastal sequences in the southern bay of Biscay

The main sedimentary features of the northern coast of the Iberian Peninsula during the Holocene transgression are characterized by the formation of estuaries, the deposition of sand bars and sand beaches, and the accumulation of aeolian dunes. These coastal deposits are very favourable for identifying Quaternary sea-level changes as they contain great volumes of well preserved sediments including marine, brackish and freshwater beds. The micropalaeontological analysis (benthic foraminifera) of diverse littoral sequences has allowed different microfaunal assemblages to be recognised and their corresponding depositional environments determined. Two recurrent phases of sediment build-up as the sea level rose have been distinguished. They have been interpreted as the consequence of two different marine advances in this region: one dated at around 8 000 years BP and the second around 2 500 years BP.     

马尼拉海湾和莱城港湾的辐射状况

本文利用在马尼拉海湾和莱城港湾考察所获得的少量辐射资料,分析了该两地区辐射各量值的日变化特征和地区差异。揭示了海(港)湾水面及其紧邻海岛陆面的辐射特征差异。这些信息很可能有助于上述地区海洋大气间热量交换的分析计算。     

广东大亚湾石珊瑚群落的分布及动态变化

2006年6月对位于南海北部亚热带的大亚湾和大鹏湾石珊瑚群落的分布、种类和覆盖率进行了调查,结果显示大亚湾共有石珊瑚24种,以秘密角蜂巢珊瑚(Favites abdita)为优势种,总覆盖率为20%,大鹏湾有石珊瑚21种,以精巧扁脑珊瑚(Platygyra daedalea)为优势种,总覆盖率为7.9%。大亚湾石珊瑚群落健康状况良好,但生长稀疏,群落密度低,空间结构简单,生长带窄;与1964年、1983年、1984年和1991年的调查结果相比,覆盖率从76.6%下降到20%,优势种从枝状的霜鹿角珊瑚(Acropora Pruinosa)转变成块状或皮壳状的秘密角蜂巢珊瑚,群落生态退化严重,主要原因可能是人为破坏活动对珊瑚本身以及生长环境造成的压力所致,包括过度捕捞、盗采珊瑚、沿岸施工和水体污染等,建议采取相应的保护措施。     

The light transmission and seiche depth of Izmir Bay,western Turkey

Izmir Bay is one of the most polluted estuaries in the whole Mediterranean Sea. The inner part of the Bay (Inner Bay) is heavily affected by domestic and industrial discharge. As a result of these loads, strong eutrophication occurs in the Inner Bay, which is temporally anaerobic. The ecologically sensitive approach of the local authorities during the last decade has given rise to a wide variety of monitoring and research studies on this bay. On the other hand, the municipality of Izmir started to operate wastewater treatment facilities since January 2000. The Institute of Marine Sciences and Technology — Izmir (IMST) with its research vessel R/V K Piri Reis has been conducting an intensive monitoring program since 1988 and especially during the recent few years. These investigations provide an opportunity for the evaluation of the performance of the wastewater treatment plant in terms of the change in the optical properties of Izmir Bay water in a positive manner. The turbidity values measured in these monitoring studies indicate that the values have changed drastically after January 2000. Their spatial variation indicates that the values decrease from the Inner Bay towards the Aegean Sea. The turbidity (light transmission) values are measured with an automatic CTD (conductivity, temperature and depth) system during each cruise. The seiche disc depth measurement is carried out only occasionally. The accuracy of the seiche disc depth is dependent on certain daylight conditions and depends on the operator. The seiche disc depth (D _s) is an important parameter to estimate primary production of organic matter (hereafter called production). A relation between light transmission (turbidity) value and seiche disc depth (D _s) is found with very good agreement. The correlations are very high (approximately 0.94) with slight seasonal variation.     

Spatially discontinuous modern sedimentation in Georgian Bay, Huron Basin, Great Lakes

High-resolution seismic reflection profile data show that the modern sediment cover (over the last 150 years) in Georgian Bay is thin and spatially discontinuous. Sediments rich in ragweed pollen, largely derived from siltation linked to land clearing and European settlement, form a thin, discontinuous veneer on the lakebed. Much of the lakebed consists of exposed sediments deposited during the late glacial or early postglacial. Accumulation rates of modern sediments range from < 0 mm/year (net erosion) to ∼3.2 mm/year, often within a few hundred metres spatially. These rates are much lower than those reported for the main basin of Lake Huron and the other Great Lakes, and are attributed to the low sediment supply. Only a few small rivers flow into Georgian Bay, and most of the basin is surrounded by bedrock of Precambrian gneiss and granite to the east, and Silurian dolostone, limestone and shale to the west. Thick deposits of Pleistocene drift, found on the Georgian Bay shoreline only between Meaford and Port Severn, are the main sediment source for the entire basin at present. Holocene to modern sediments are even absent from some deep basins of Georgian Bay. These findings have implications for the ultimate fate of anthropogenic contaminants in Georgian Bay. While microfossil assemblages in the ragweed-rich sediments record increased eutrophication over the last 150 years, most pollutants generated in the Georgian Bay catchment are not accumulating on the lakebed and are probably exported from the Bay.     

Micromorphological Analysis of Coastal Sediments from Willapa Bay, Washington, USA: A Technique for Analysing Inferred Tsunami Deposits

Tsunami deposits are provisionally distinguished in the field on the basis of anomalous sand horizons, fining-up and fining-landward, coupled with organic-rich, fragmented `backwash' sediments. In this paper, micromorphological features of a sediment sequence previously interpreted as being of tsunami origin are described. These characteristics are shown to be consistent with the macro-scale features used elsewhere, but show additional details not seen in standard stratigraphies, including possible evidence for individual waves, possibly wave-magnitude progression, organic fragment alignment and intraclast microstructures. Although replication and more complete studies are needed, this analysis confirms the identification of a tsunami in Willapa Bay in ca.1700 AD, while demonstrating a widely applicable technique for confirming or refuting possible tsunami deposits.