Total mercury in sediments and in Brazilian Ariidae catfish from two estuaries under different anthropogenic influence

Santos-São Vicente estuary, located in São Paulo State, Brazil, has a history of contamination by inorganic chemicals such as mercury (Hg). In the 1980s the Cubatão was considered one of the most polluted sites in the world as a consequence of the intense industrial activities located in the city close to the estuary. To provide data and evaluate the local biota, total mercury (THg) contents were determined in sediments and in fish, Cathorops spixii, from different areas of the Santos-São Vicente estuary. For comparison, samples were also collected in a non-polluted system with similar hydrochemistry characteristics, the Cananeia estuary. The water characteristics and THg levels in sediment and fish samples confirmed a high human influence in the Santos-São Vicente estuary. The lowest THg values, observed in Cananeia, were evidence of low anthropogenic influence. High values observed in Santos-São Vicente show the necessity for a monitoring program.     

验证技术：选择地震属性和验证其结果的技术

为了更好地确定井间岩石属性，特别是进行府层研究的需要，已经导致不断利用地震首属性作为岩石属性的标记，加果在井位能够确定地震和岩石属性的有效的关系，可以大大地降低井间的不确定性。     

Coral skeletal delta(15)N reveals isotopic traces of an agricultural revolution

This study introduces a new method of tracing the history of nutrient loading in coastal oceans via delta(15)N analysis of organic nitrogen preserved in the skeleton of the massive Porites coral. Four coral cores were collected in Bali, Indonesia, from reefs exposed to high levels of fertilizers in agricultural run-off, from lagoonal corals impacted by sewage, and from a reef located 30 km offshore. Skeletal delta(15)N in the agriculturally exposed coral declined from 10.7+/-0.4 per thousand in 1970-1971, when synthetic fertilizers (-0.8 per thousand+/-0.2 per thousand) were introduced to Bali, to a depleted "anthropogenic" baseline of 3.5 per thousand+/-0.4% in the mid-1990s. delta(15)N values were negatively correlated with rainfall, suggesting that marine delta(15)N lowers during flood-bourn influxes of waste fertilizers. Reef cores exposed to untreated sewage in terrestrial discharge were enriched (7.8 and 7.3+/-0.4 per thousand), while the offshore core reflected background oceanic signals (6.2+/-0.4 per thousand). delta(15)N, N concentration, and C:N systematics indicate that the N isotopic composition of skeletal organic matter was generally well preserved over 30 years. We suggest that skeletal organic delta(15)N can serve as a recorder of past nitrogen sources. In Bali, this tracer suggests that the intensification of Western style agricultural practices since 1970 are contributing to the degradation of coastal coral reefs.     

A modification to the Bouwer and Rice method of slug-test analysis for large-diameter, hand-dug wells

The Bouwer and Rice method of estimating the saturated hydraulic conductivity (Ks) from slug-test data was evaluated for geometries typical of hand-dug wells. A two-dimensional, radially symmetric and variably saturated, ground water transport model was used to simulate well recovery given a range of well and aquifer geometries and unsaturated soil properties, the latter in terms of the van Genuchten parameters. The standard Bouwer and Rice method, when applied to the modeled recharge rates, underestimated Ks by factors ranging from 1.3 to 5.6, depending on the well geometry and the soil type. The Bouwer and Rice analytical solution was modified to better explain the recovery rates as predicted by the numerical model, which revealed a significant dependence on the unsaturated soil for the shallow and wide geometries that are typical of traditional wells. The modification introduces a new parameter to the Bouwer and Rice analysis that is a measure of soil capillarity which improves the accuracy of Ks estimates by tenfold for the geometries tested.     

Benthic changes during 10 years of organic enrichment by McMurdo Station, Antarctica

A benthic habitat along the coast of McMurdo Station in the Ross Sea, Antarctica is enriched by sewage from the station and altered by hydrocarbons and heavy metals in an adjacent historic dumpsite. We report on 10 years of change in the benthic communities from 1988 to 1998 and compare enrichment effects at Australia's Casey Station, East Antarctica. Despite being 14 km apart, reference communities upcurrent and downcurrent of McMurdo Station remained closely similar over time, dominated in all years by a tube building polychaete, Spiophanes tcherniae. The community bordering McMurdo Station was generally a third as abundant as communities at the reference sites over the decade of sampling, although diversity was as high or higher, except in the most contaminated areas. In 1992, organic enrichment of the outfall community intensified and within the year, the opportunistic polychaetes Aphelochaeta sp., Ophryotrocha notialis, Capitella perarmata, and Leitoscoloplos kerguelensis became dominant. Since 1996, two of the three enriched communities have increased in resemblance to the reference communities. Given the observed responsiveness of the benthos to the outfall so far, further changes are anticipated within the year following implementation of sewage treatment in 2003. Organic enrichment by McMurdo Station has had a greater impact on benthic community structure than at Australia's Casey Station.     

热带海洋全球大气计划的海气耦合响应试验（COARE）

热带海洋全球大气计划的海气耦合响应试验（ＣＯＡＲＥ）Ｊ．Ｓ．Ｇｏｄｆｒｅｙ（澳大利亚）１引言１９９２年１１月－１９９３年２月，在巴布亚新几内亚以东地区进行了热带海洋全球大气计划（ＴＯＧＭ）的海气耦合响应试验（ＣＯＡＲＥ），这是人们已进行的阵容最强的海...