Oregon Beach Monitoring Program: Bacterial exceedances in marine and freshwater creeks/outfall samples, October 2002-April 2005

A total of 3086 samples, both marine (2916) and freshwater creeks/outfall samples (170) were collected and analyzed for enterococci during October 2002-April 2005, from 52 designated beaches in Oregon. A total of 3.2% (99/3086) of the samples at 21 beaches exceeded 158 most probable number (MPN)/100 milliliters (mL). The average enterococci levels of these 99 exceedances was 559 MPN/100 mL, with a maximum of 4352 MPN/100 mL (Otter Rock and Ona) and a minimum of 160 MPN/100 mL (Sunset Bay State Park, Bastendorff, and Mill). For marine water, 77/2916 (2.6%) exceeded 158 MPN/100 mL. For freshwater, 22/170 (12.9%) exceeded 158 MPN/100 mL, with a maximum of 587 MPN/100 mL at Sunset Bay. Sixty percent of the marine and 9% of freshwater exceedances occurred during the winter. Seventy-two percent (55/77) of the marine exceedances occurred after rainfall events (0.01-60.0 mm). At Harris and Mill Beaches, cumulative rainfall was highly correlated with bacterial densities, R = 0.7. Rainfall, at both beaches, explained about one-half the variation in log10 bacteria density (R2 = 0.5). Additional monitoring is warranted to further characterize bacterial contamination in Oregon waters.     

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.     

Eutrophication and hypoxia in four streams discharging in Guanabara Bay, RJ, Brazil, a case study

Four streams in the city of São Gonçalo, were sampled to evaluate their potential as sources of nutrients to Guanabara Bay aiming to contribute with the government program to decrease the levels of pollution in this area. Imbuaçu, Guaxindiba, Marimbondo and Brandoas streams were sampled in 2007, 2008 and 2009. The streams revealed to be hipereutrophic with severe limitation of primary production by nitrogen, as shown by the N/P molar ratio. Phosphate levels were abnormally high varying between 4.35 and 130.82 μM, whereas nitrate and nitrite ranged from 0.06 to 54.05 μM and from 0.28 to 19.23 μM, respectively. The streams also presented severe hypoxia and anoxia, with oxygen values varying from non-detected to 3.72 ml l⁻¹. Heavy loads of particulate suspended material were recorded in the studied streams, ranging between 6.00 and 400.00 mg l⁻¹. The streams were considered inexorable sources of nutrients, enhancing the severe eutrophication process in Guanabara Bay.     

Enantioselectivity of polychlorinated biphenyl atropisomers in sediment and biota from the Turtle/Brunswick River estuary, Georgia, USA

To investigate the potential for enantioselective transformation and accumulation, the enantiomer distributions of seven polychlorinated biphenyl (PCB) atropisomers were measured in the sediment and biota from a sub-tropical estuary heavily contaminated with Aroclor 1268, a technical mixture of highly chlorinated PCB congeners. Enantiomer fractions (EFs) of PCBs 91, 95, 136, 149, 174, 176, and 183 in marsh sediment, invertebrate, forage and predatory fish species, and bottlenose dolphins were determined. Non-racemic EFs greater than 0.75 were found in sediments for PCBs 136 and 174, likely the result of microbial dechlorination. Although enantiomer fractions in grass shrimp (Palaemonetes spp.) mirrored those of sediment, fish species had EFs that differed significantly from sediment or grass shrimp. Similarly, bottlenose dolphins were also found to contain non-racemic quantities of PCBs 91, 136, 174, 176, and 183. Non-racemic EFs in these biota were likely a result of both uptake of non-racemic proportions of PCBs from the diet and enantioselective biotransformation.     

Development of the sediment and water quality management strategies for the Salt-water River, Taiwan

The Salt-water River watershed is one of the major river watersheds in the Kaohsiung City, Taiwan. Water quality and sediment investigation results show that the river water contained high concentrations of organics and ammonia-nitrogen, and sediments contained high concentrations of heavy metals and organic contaminants. The main pollution sources were municipal and industrial wastewaters. Results from the enrichment factor (EF) and geo-accumulation index (Igeo) analyses imply that the sediments can be characterized as heavily polluted in regard to Cd, Cr, Pb, Zn, and Cu. The water quality analysis simulation program (WASP) model was applied for water quality evaluation and carrying capacity calculation. Modeling results show that the daily pollutant inputs were much higher than the calculated carrying capacity (1050 kg day(-1) for biochemical oxygen demand and 420 kg day(-1) for ammonia-nitrogen). The proposed watershed management strategies included river water dilution, intercepting sewer system construction and sediment dredging.     

维特瓦特斯兰德金—铀砾岩矿床成因争论新进展

在对世界著名的维特瓦特斯兰德矿床成因讨论中，存在着2种主要观点：热液交代说和砂积成因说。后者经过补充、修改演变为改造砂矿成因说。最近，加拿大地质学家Reimer和Mossman代表后一种观点撰文，概括了近年来争论的焦点，回答了热液成因论者的质疑。     

Biogeochemical conditions in sediments enriched by organic matter from net-pen fish farms in the Bolinao area, Philippines

Sedimentation and sediment metabolism was measured at eight active milkfish fish pens and at one abandoned site in the Bolinao area, Philippines in order to examine the interactions between sediment and water in this shallow coastal zone. The rates of sedimentation were high in the area due to siltation, but the activities in the fish pens also contributed to enhanced sedimentation as indicated by the difference between the abandoned and active sites. The sediment metabolism appeared to decrease with increasing rates of sedimentation indicating that the microbial activity reached a saturation level in the fish pen sediments. Anaerobic processes dominated the organic matter decomposition, and sulfate reduction rates are among the highest measured in fish farm sediments. The rates decreased with increasing organic loading despite high concentrations of sulfate (>10 mM) at all sites. Presence of methane bubbles in the sediments suggests that sulfate reduction and methanogenesis were coexisting. The sediment metabolism was significantly reduced at the abandoned site indicating that the stimulation of microbial activities is due to active fish production. The anaerobic activity remained high at the abandoned site indicating that the sediment biogeochemical conditions remain affected long time after fish production has ceased.     

小行星中心简史

本文扼要介绍国际小行星中心的简史,同时也概括了小行星研究的历史,现状和展望。全文共13节:1.两个时期 2.19世纪的工作 3.计算研究所 4.小行星中心的创始5.理论天文研究所 6.用电子计算机计算摄动 7.小行星索引 8.迁往剑桥(美) 9.证认工作 10.小行星的编号 11.小行星的观测者 12.特殊小行星 13.展望未来。     

Partial mortality in massive reef corals as an indicator of sediment stress on coral reefs

Partial mortality and fission on colonies of four common massive coral species were examined at sites differing in their exposure to river sediments in St. Lucia, West Indies. Rates of partial mortality were higher close to the river mouths, where more sediments were deposited, than away from the rivers in two coral species. Frequency of fission showed no significant trend. The percent change in coral cover on reefs from 1995 to 1998 was negatively related to the rate of partial mortality estimated in 1998 in all species. This suggests that partial mortality rates could reflect longer-term temporal changes in coral communities. Similar conclusions could also be reached using a less precise measure and simply recording partial mortality on colonies as <50% and >/=50% dead tissue. We conclude that partial mortality in some species of massive reef corals, expressed as the amount of dead tissue per colony, could provide a rapid and effective means of detecting sediment stress on coral reefs.