Influence of the annual sardine run on catches of large sharks in the protective gillnets off KwaZulu-Natal,South Africa,and the occurrence of sardine in shark diet

Shark catches in the protective nets set off the beaches of KwaZulu-Natal (KZN), South Africa, are strongly influenced by the sardine run, the winter influx of shoals of Sardinops sagax from the south-west. The effect of the sardine run, which is highly variable from year to year, is greatest in June and July at beaches south of Durban. Total annual shark catch and effort are presented for the period 1952–2005, and total monthly shark catch on the KZN south coast for the period May–August, 1965–2005. Measures to reduce catches of sharks associated with the sardine run have been introduced and have been increasingly successful. Reliable species-specific catch data are available for the period 1978–2005 only. For this period, the spatio-temporal distribution of each of 14 species of shark and the frequency of occurrence of sardine in their diets is documented. Occurrence varies according to species, as does the apparent influence of the sardine run on shark distribution. During June and July on the KZN south coast, sardine were found in the diet of all but two species and frequency of occurrence was 40% or greater in eight species. The presence of copper or bronze whaler sharks Carcharhinus brachyurus in KZN waters appears to be strongly associated with the sardine run, as does that of certain life-history stages of dusky sharks C. obscurus. Spinner sharks C. brevipinna and smooth hammerhead sharks Sphyrna lewini are caught in greater numbers in summer than in winter, but appear to shift their spatial distribution seasonally to feed on sardine.     

冻融循环对黏质粗粒土单轴抗压性能影响的试验研究

循环冻融作用下粗粒土的力学性质对于高寒地区边坡稳定性分析意义重大。以藏区某一排土场土体作为依托,开展了不同冻融循环次数后不同级配黏质粗粒土的单轴压缩试验,研究冻融循环作用对黏质粗粒土单轴抗压性能的影响。结果表明：冻融循环作用对黏质粗粒土应力-应变关系曲线性状及破坏模式有一定的影响,可使其应变呈现由脆性破坏（软化）向塑性流动（硬化）变化的规律。当提高冻融循环次数时,该类土体的弹模和抗压强度均显著减小,其中5~9次冻融循环前减小幅度较大,之后基本保持不变。单轴抗压性能的弱化与土样循环冻融过程中伴随的细颗粒团聚、大中孔隙增多、密实度下降有关。20次冻融循环后,该土质土样抗压强度、弹模最大降低幅度各自高达43%和77%。可见随着提高细砾组的含量,土样的抗压强度和弹模均呈现下降的趋势,这与该土样内粗、细土颗粒的比例及强度发挥机理密切相关。粗粒土单轴抗压破坏应变随冻融循环次数和细砾组含量的增加有一定的增加趋势。     

The ecology of Lerista labialis (Scincidae) in the Simpson Desert: reproduction and diet

This study investigated the diet and reproductive cycle of the southern sandslider skink Lerista labialis, in the dunefields of the Simpson Desert, central Australia. We dissected preserved specimens to obtain gut contents and measure gonad volume, and also live-captured animals from 1999 to 2000 to assess the impact of rainfall on population structure and body condition. This skink breeds during the austral summer. Males start spermatogenesis in July and testes volume is largest in December. Females have enlarged ovarian follicles in November and produce oviducal eggs from November to February. One or more clutches of two eggs are produced per breeding season. L. labialis specializes on termites, which represent 78% of the diet by percentage occurrence. The remaining 22% of this skink's diet comprises Hemiptera, Neuroptera and unknown prey items. Body condition, and probably increased reproduction and juvenile survival, were higher in 2000 (wet year) than 1999 (relatively dry year); proportion of juveniles also increased in the population in autumn, winter and summer 2000 compared to the previous year. Late rainfall in autumn 2000 may have triggered these demographic changes by increasing prey accessibility. Long-term research is required into growth rates, longevity and inter-annual population dynamics of L. labialis to fully evaluate its life history strategy.     

Petrographic and geochemical study of Jurassic dolostones from Lebanon: Evidence for superimposed diagenetic events

The Jurassic rock sequence in Lebanon is characterized by pervasive dolomitization (thickness > 1000 m). Two distinct dolostones are recognized within this rock succession: fine-to-medium crystalline seepage-reflux grey dolostone and coarse-crystalline hydrothermal beige dolostone. In this contribution, field, petrographic, and geochemical investigations on a dolostone ‘tongue’, occurring in Late Jurassic carbonates in central Lebanon, are discussed. The dolostone ‘tongue’ consists predominantly of the beige Late Jurassic hydrothermal dolostones. During and/or after the deposition of the overlying continental sandstones (Early Cretaceous), meteoric water percolated through the sand layers and into the underlying beige dolostones. This resulted first in dolomite intracrystalline dissolution, and then in the precipitation of oxides/hydroxides within the pore space. Finally, the precipitation of ferroan dolomite cement — from reduced fluids during a new stage of burial — took place. This study attempts to explain how superimposed diagenetic events result in a single pervasive dolostone body.     

贵州关岭生物群盘江鱼龙体内胃融物研究

本文主要描述了关岭生物群中一美丽盘江鱼龙标本（YIGM V30016）-Panjiansaurus epicharis Chen＆Cheng体内的胃融物。其组成物质为微晶含有机质胶磷质生物碎屑灰岩。其中生物碎屑主要为较小的鱼类骨碎片．其次含有少量的双壳类外壳，没有胃石。通过分析胃融物的成分，比较牙齿类型和身体特征等，认为盘江鱼龙主要以小型鱼类和双壳类为食，并不需胃石帮助消化食物。     

First evidence of fiberglass ingestion by a marine invertebrate (Mytilus galloprovincialis L.) in a N.W. Mediterranean estuary

Alfacs Bay is a N.W. Mediterranean estuary important for mussel (Mytilus galloprovincialis) aquaculture. During studies at the site, fiberglass particles were detected. The presence of fiberglass occurred naturally in the water throughout the study period (November 2006 to July 2007). An investigation was undertaken into its role in the feeding behavior of the local mussels. Fiberglass was present in all types of mussel samples. Rejection, which we would have expected for the whole study period, was only evident during the second season studied. To our knowledge, this is the first report of the ingestion of fiberglass by a marine organism. Our novel finding indicates the need to investigate fiberglass ingestion by marine organisms at different levels of the food web and the possible implications for human health and the health of the organisms themselves. In addition, we propose the use of mussels as sentinel organisms to monitor fiberglass contamination in marine ecosystems.     

《中国岩溶》网络影响特征及其分析

为能比较确切地了解《中国岩溶》的网络影响力和明确今后办刊的努力方向,以中国知网( CNKI)中心网站2005年1月1日— 2007年3月15日的日志记录资料为依据,运用CNKI所提供的期刊文献评价统计分析系统软件对《中国岩溶》的网络传播特征进行了统计分析。结果表明, 1982— 1998年,由于论文的时效性等原因, 《中国岩溶》被访问和下载量比较小, 1982— 1993年所出版的论文平均每篇受访、下载率不足0. 7和0. 4次, 1994— 1998年为20. 1和7. 1次,属《中国岩溶》论文被访问下载量基本无升幅和小额度升幅时段; 1999年以后,由于能够主动地根据国家社会经济发展需要,及时调整选题并加强生态环境、水资源开发、环境地质等研究领域的组稿力度,被访问下载量明显提高,平均每篇被访问、下载率分别达78. 9次和34. 8次,为《中国岩溶》论文被访问下载的高额度升幅时段。当前《中国岩溶》网络传播存在的主要问题是国外网络传播能力比较小等,亟待通过不断加强海外宣传及规范中英文摘要的编写等手段加以解决。      

含水率对加筋膨胀土强度的影响

通过室内加筋三轴剪切试验,得出最优含水率附近两种不同含水率的加筋膨胀土的应力-应变关系曲线。分析试验曲线可知,相同含水率时试样的强度随着加筋层数、周围压力的增加而增大;同围压、同加筋层数的试样的含水率略微的减少,引起强度明显的增加,表明加筋膨胀土强度的水敏感性。     

九龙江口、厦门西海域无机氮的分布与转化

1987年3月至1988年12月笔者在九龙江口及厦门西海域调查结果表明九龙江口与厦门西海域无机氮含量较高,分别为28.25和18.76μmol/L,NO_3-N是该海域氮的主要存在状态,NH_4-N也是较重要的形态。九龙江溶解无机氮入海通量估算为6千吨/年。氮的循环、转化对于维持厦门西海域生产力水平有重要的作用。NO_3-N、NO_2-N、NH_4-N分布的季节变化主要是受生物活动的影响。     

温度、光照、氮含量对微绿球藻生长及脂肪酸组成的影响

报道了环境因子对微结球藻（Nannochloropsis oculata)的生长速率及脂肪酸组成的影响，结果表明：微绿球藻具有较快的生长速度，且富含16：1（n-7)和20：5（n-3)(EPA)。适温范围为0－30℃，最适温度为20℃，温度对脂肪酸组成的影响较明显，EPA在20摄氏度时最高，30℃时急剧下降，生长较适宜光强为5000－7000lx，但在1000lx时EPA产率最大；氮含量为10mg/L时生长速度最快，但此时EPA含量较低。