Bioavailability of heavy metals bound to sediments affected by a mining spill using Solea senegalensis and Scrobicularia plana

After the Aznalcóllar mining spill (April, 1998) different ecosystems along the Guadiamar river and the Guadalquivir estuary were impacted by high concentrations of metals. The concentration of metals Zn, Cd, Pb, Cu and As has been detected as a good tracer of the pathway of the toxic spill. Different individuals of the fish Solea senegalensis and the clam Scrobicularia plana were exposed to contaminated sediments after the accidental spill in the south-west Spain. The induction of metallothioneins in fish and the bioaccumulation of metals in clams were determined in different tissues to determine the biological adverse effect associated with the heavy metals from the spill. A relationship between the enrichment of metals in the tissues and the induction of metallothioneins was determined for those assays performed using contaminated sediments. The bioaccumulation of metals indicates that the risk associated with the spill should be continuously evaluated to establish the sublethal effects related to the accident.     

Evaluating prey capture by larval mummichogs (Fundulus heteroclitus) as a potential biomarker for contaminants

We evaluated larval prey capture as a "behavioral biomarker" of contamination by examining feeding behavior of larval mummichogs (Fundulus heteroclitus) from many different sites, including a severely contaminated "Superfund" site, moderately contaminated sites, and reference areas. Prey capture ability was related to sediment contaminant levels. The levels of contaminants at a site were highly correlated with each other, so that the impact of individual contaminants was confounded. The number of captures of brine shrimp by mummichog larvae from all sites was highly variable, but significant negative correlations of prey capture were seen with mercury, lead, zinc, cadmium, and PCBs. As observed previously with adults, polyaromatic hydrocarbons (PAHs) did not appear to impair prey capture ability. The only site in which prey capture rates of 8-day old larvae were severely affected was the most highly contaminated Superfund site, Berry's Creek, NJ. This implies that larval prey capture is not as sensitive a behavioral biomarker for contamination as adult behavior studied previously.     

南黄海浅层声学地层的初步探讨

利用数字地震仪、地质脉冲仪和3.5kH_Z真浅层剖面仪测量结果显示:南黄海地层可分为三个大层组,即第四系、上第三系和下第三系(或第三系以前的地层)。它们分别沉积在南、北两个沉积中心中,这两个沉积中心始终控制着盆地的沉积。在盆地发展过程中,西部大陆的物质一直是盆地沉积的主要物质来源。第四纪时,黄河已经显示了它对南黄海影响的主导地位。无论是第三纪还是第四纪沉积物均以陆相为主。第四纪的地质历史是复杂多变的,至少有两次以上的成陆过程。     

应用生态模型研究近海贝类养殖的可持续发展

建立了一个贝藻混养生态模型，并应用于桑沟湾栉孔扇贝、太平洋牡蛎和海带混养生态系统的模拟。这一模型在个体生长模型的基础上模拟种群的生长情况；通过模拟不同播苗养殖和收获方式下的产量，以及不同混养方式对海洋生态系统的影响来确定养殖容量。采用该模型的研究结果表明：当养殖密度分别增加到目前扇贝和牡蛎放苗量的2倍和15倍时总产量最高(达到养殖容量)，但单位面积产量和产量／播苗比减少，因此效益是下降的；扇贝放苗量增加到目前的15倍，牡蛎增加到30倍时会导致养殖生产崩溃，同时生态系统也发生改变：在目前养殖密度下，桑沟湾向黄海输出初级生产产品，但是当放苗密度增加到15～20倍时，桑沟湾需要黄海向其输入初级生产产品。上述结果表明，该模型可以迅速模拟养殖生物量和生态系统的变化，在多元养殖管理中可作为一种有效的管理工具。     

秦岭-大别-苏鲁和弗朗西斯科变质带的板块构造格局对比

秦岭－大别－苏鲁和弗朗西斯科变质带的板块构造格局对比Ｗ．Ｇ．Ｅｒｎｓｔ和Ｊ．Ｇ．Ｌｉｏｕ大别－苏鲁地区：大陆碰撞（阿尔卑斯型）的超高压产物长达２０００ｋｍ的秦岭－大别－苏鲁褶皱带标志着呈东西向延伸的中国东部中－朝克拉通和杨子克拉通之间结合带。该大地构...     

Elevation of cytochrome P450-immunopositive protein and DNA damage in mussels (Mytilus edulis) transplanted to a contaminated site

Mytilus edulis were collected from a reference site (Port Quin) and an urban/industrial contaminated site (New Brighton) in the UK during June 1999. Levels of PCBs (sigma7 congeners) and CB-138 were determined to be, respectively, 21 fold and 16 fold higher in the mussel digestive glands from New Brighton. Levels of CYPIA-immunopositive protein were 1.5 fold higher (P < 0.05) at the polluted site but the levels of DNA strand breaks were 1.3 fold higher (P<0.05) at the reference site. Mussels from Port Quin were placed in cages at both sites and both transplanted and indigenous populations sampled in September (13 weeks). Mussels transplanted from the reference site to the industrial site, reported elevated levels of CYP1A-immunopositive protein (1.4 fold; P < 0.05) and higher levels of DNA damage (1.2 fold; P < 0.05) compared to caged populations at the reference site and a PCB loading similar to the populations from the polluted site. Moreover, transplanted mussels had DNA damage 1.8 fold greater (P < 0.05) than indigenous mussels at the transplant site. These changes were small but significant when compared to the observed temporal changes in the indigenous populations.     

几个风暴潮预报模型的实例

对给定的地点,可应用几种定型的模型正确地预报潮位。然而,在风暴条件下,潮位的观测值和预报值之间存在着差值,这个差值称作风暴潮。对位于塞纳河河口的勒阿弗尔港,同时用二种风暴潮预报模型:自回归模型和一种需用当地风、气压资料的模型。 自回归模型能用来作时效为5小时的预报;用勒阿弗尔气象台36小时内的风,气压的预报值,便可用第二种预报模型,给出39小时时效的风暴潮预报。     

The impact of oestrogenic and androgenic contamination on marine organisms in the United Kingdom--summary of the EDMAR programme. Endocrine Disruption in the Marine Environment

This paper summarises results of the EDMAR programme which is investigating oestrogenic and androgenic endocrine disruption in UK coastal waters. Most of the data concern fish. Four species (flounder, viviparous blenny and two sand gobies) are experiencing feminisation in industrialised estuaries. In males this includes vitellogenin (VTG) synthesis, ovotestis induction and/or feminised sexual characteristics. Although reproductive success may be impaired in some cases, implications for fish populations are still unclear. Suspected causative contaminants include natural oestrogenic substances and synthetic oestrogen mimics. The majority of the oestrogenic activity is adsorbed to sediments, and routes of exposure may include benthic food chain transfer. Some natural androgenic substances are also being discharged to estuaries, but their activity appears low.