EFFECTS OF CLIMATE CHANGE ON INLAND WATERS OF THE PACIFIC COASTAL MOUNTAINS AND WESTERN GREAT BASIN OF NORTH AMERICA

The region designated as the Pacific Coastal Mountains and Western Great Basin extends from southern Alaska (64°N) to southern California (34°N) and ranges in altitude from sea level to 6200 m. Orographic effects combine with moisture-laden frontal systems originating in the Pacific Ocean to produce areas of very high precipitation on western slopes and dry basins of internal drainage on eastern flanks of the mountains. In the southern half of the region most of the runoff occurs during winter or spring, while in the northern part most occurs in summer, especially in glaciated basins. Analyses of long-term climatic and hydrological records, combined with palaeoclimatic reconstructions and simulations of future climates, are used as the basis for likely scenarios of climatic variations. The predicted hydrological response in northern California to a climate with doubled CO₂ and higher temperatures is a decrease in the amount of precipitation falling as snow, and substantially increased runoff during winter and less in late spring and summer. One consequence of the predicted earlier runoff is higher salinity in summer and autumn in San Francisco Bay. In saline lakes, the incidence of meromixis and the associated reduction in nutrient supply and algal abundance is expected to vary significantly as runoff fluctuates. In subalpine lakes, global warming will probably will lead to increased productivity. Lacustrine productivity can also be altered by changes in wind regimes, drought-enhanced forest fires and maximal or minimal snowpacks associated with atmospheric anomalies such as El Niño–Southern Oscillation (ENSO) events. Reduced stream temperature from increased contributions of glacial meltwater and decreased channel stability from changed runoff patterns and altered sediment loads has the potential to reduce the diversity of zoobenthic communities in predominately glacier-fed rivers. Climatic warming is likely to result in reduced growth and survival of sockeye salmon in freshwater, which would, in turn, increase marine mortality. Further research activities should include expanded studies at high elevations and of glacier mass balances and glacial runoff, applications of remote sensing to monitor changes, further refinement of regional climatic models to improve forecasts of future conditions and continued analyses of long-term physical, chemical and biological data to help understand responses to future climates. © 1997 John Wiley & Sons, Ltd.     

Emerging organic contaminants in coastal waters: Anthropogenic impact,environmental release and ecological risk

This study provides a first estimate of the sources, distribution, and risk presented by emerging organic contaminants (EOCs) in coastal waters off southwestern Taiwan. Ten illicit drugs, seven nonsteroidal anti-inflammatory drugs (NSAIDs), five antibiotics, two blood lipid regulators, two antiepileptic drugs, two UV filters, caffeine, atenolol, and omeprazole were analyzed by solid-phase extraction and liquid chromatography coupled to tandem mass spectrometry (SPE–LC–MS/MS). Thirteen EOCs were detected in coastal waters, including four NSAIDs (acetaminophen, ibuprofen, ketoprofen, and codeine), three antibiotics (ampicillin, erythromycin, and cefalexin), three illicit drugs (ketamine, pseudoephedrine, and MDMA), caffeine, carbamazepine, and gemfibrozil. The median concentrations for the 13 EOCs ranged from 1.47 ng/L to 156 ng/L. Spatial variation in concentration of the 13 EOCs suggests discharge into coastal waters via ocean outfall pipes and rivers. Codeine and ampicillin have significant pollution risk quotients (RQ > 1), indicating potentially high risk to aquatic organisms in coastal waters.     

Application of oxidative stress indices in natural populations of Perna viridis as biomarker of environmental pollution

Oxidative stress indices were measured in gills and digestive glands of Perna viridis collected from three coastal locations in Goa i.e., Bambolim, Marmugao Harbour and Malim. In addition to lipid peroxidation, the activities of antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione S-transferase and two non-enzymatic antioxidants (ascorbic acid and reduced glutathione) were investigated in order to understand their variation with respect to pollution status of the sampling locations. We observed a significant increase in lipid peroxidation and antioxidant enzymes of both the tissues at Mormugao Harbour and Malim, suggesting that the animals at these two locations are at higher level of oxidative stress as compared to those at Bambolim. Conversely, low levels of non-enzymatic antioxidants such as ascorbic acid and reduced glutathione, observed at Mormugao Harbour and Malim indicate that the animals may use these compounds to counteract stress in the tissues. This study shows that changes in lipid peroxidation, superoxide dismutase, catalase, glutathione reductase, glutathione S-transferase and reduced glutathione in tissues of P. viridis can be used as molecular biomarkers in environmental monitoring programs.     

我国南部海域条纹斑竹鲨线粒体DNA控制区遗传多态性研究

摘要:在对我国南部沿海闽东、闽南、粤西、海南、北部湾5个海域的条纹斑竹鲨群体线粒体控制区多态性研究中,获得长度为1 094~1 096 bp的线粒体控制区完整序列。序列比对发现了6个多态性核苷酸位点,定义了8个单倍型。5个群体的单倍型多样度(h=0.542 5~0.744 8)和核苷酸多样度(π=0.000 571~0.000 980)均处于较低水平,说明条纹斑竹鲨的线粒体DNA进化速率较低。分子方差分析(AMOVA)结果显示群体间的遗传差异较小(Fst=0.216 26,P<0.000 1),变异主要发生在群体内部。10 000步Markov链计算的群体间遗传分化概率及单倍型系统地理学分析结果将5个群体分成两个地理种群(台湾海峡种群、南海北部种群)。综合分析表明条纹斑竹鲨的基因流主要在浅海近岸水域扩散,遗传变异程度受地理结构和距离隔离影响。     

Geothermometry applications for the Balıkesir thermal waters,Turkey

In this study, reservoir temperatures of Balıkesir geothermal waters in northwestern Turkey are estimated with various geochemical models. The geothermal fluids in the region are represented by Na–SO₄, Na–HCO₃ and Ca–HCO₃ type waters with discharge temperatures up to 98°C. It was determined that the solubility of silica in most of the waters is controlled by the chalcedony phase. Equilibrium states of the Balıkesir thermal waters studied by means of Na–K–Mg–Ca diagram, mineral saturation calculations and activity diagrams in the system composed of Na₂O–CaO–K₂O–Al₂O₃–SiO₂–H₂O phases approximate a reservoir temperature of about 120°C. Most of the waters are found to be equilibrated with calcite, chalcedony ± quartz and muscovite at predicted temperature ranges, similar to those calculated from the chemical geothermometers.     

Mediterranean saline streams in southeast Spain: What do we know?

Many Mediterranean streams in arid and semiarid areas are naturally saline systems due to the presence of evaportic rocks of Miocene or Triassic origin. Despite the fact that these aquatic ecosystems are rare in Europe, they are common in southeast of Spain. The environmental constraints of these semiarid saline streams are imposed by both geological and climatic conditions. This paper is a compilation and summary of the principal results obtained from various studies on semiarid saline streams in the Iberian southeast. Available data for these typical environments in the region covers diverse issues such as those regarding their physical and chemical features, typology, biodiversity, community structure and ecosystem functioning, as well as different ecological and evolutionary aspects of their biota (e.g. ecophysiological responses, life cycles and phylogeography). Issues concerning the conservation of these habitats, such as the main human uses, impacts, threats and their management are also summarised. Finally, topics in need of further research are provided. The current knowledge of saline streams in southeastern Spain highlights the physical and ecological singularity of these environments, and their high conservation value. Saline streams are particularly interesting due to their halotolerant/halophilic biota and high number of rare and endemic species.     

Distribution Study of U,V, Mo,and Zr in Different Sites of Lakes Van and Hazar,River and Seawater Samples by ICP‐MS

The aim of this study is to investigate the concentrations of U, Th, V, Mo, and Zr in natural waters taken from Turkey. Among these water species, Lake Van is the largest soda lake and the fourth largest closed basin on Earth. The water samples were collected from 51 locations between 2008 and 2009. The inductively coupled plasma‐MS was used for determinations. The obtained U and Zr concentrations are in the range of 37–110 µg L^?1 and 17–78 µg L^?1 in Lake Van and 0.53–0.81 µg L^?1 and 0.15–0.19 µg L^?1 in Lake Hazar, respectively. The concentration of uranium in other studied waters varies from the lowest 0.09 µg L^?1 in Tigris (Dicle) river to the highest 4.0 µg L^?1 in Mediterranean Sea water. Mean Mo and V concentrations in the studied water samples were found to be in ranges of 0.1–17 and 2.7–113 µg L^?1, respectively. The obtained highest U concentration in Lake Van correlates with the highest Mo and Zr levels compared to the Lake Hazar and river waters. These results imply that there is a young occurrence of uranium minerals around Lake Van. It is concluded that there is about 50.000 ton of uranium in Lake Van water.     

Use of inhibitors for coastal bacteria and phytoplankton: Application to nitrogen uptake measurement

For several decades, prokaryotic and eukaryotic inhibitors have been used to exclude bacteria from microalgal cultures and for investigating prey-predator relationships. Recently there has been considerable interest in using specific inhibitors for studying the interactions between bacteria and phytoplankton, by selective repression of either organism’s activity. The effectiveness of chemical inhibitors must be tested before applying them to natural communities to partition metabolic activities between functional groups. Six different antibiotics selected from the most commonly reported in the literature were tested, at concentrations varying from 12.5 to 100 mg L⁻¹, for their effect on bacterial growth and functional diversity of natural communities from Mediterranean coastal waters. Penicillin and streptomycin each at a final concentration of 100 mg L⁻¹ significantly reduced bacterial growth within 2 h. There was a greater impact on bacterial functional diversity when both antibiotics were mixed together. This mixture did not have any significant effect on the growth of selected cultured phytoplankton strains, whereas the eukaryote inhibitor cycloheximide at 100 mg L⁻¹ reduced growth within 2 h of incubation. The penicillin–streptomycin mixture and cycloheximide alone successfully partitioned NH₄⁺ and NO₃⁻ uptake between bacteria and phytoplankton bi-weekly sampled in a coastal lagoon in Autumn, where bacterial contribution to total NH₄⁺ and NO₃⁻ uptake averaged 46 and 41%, respectively. The use of specific inhibitors may be a valuable method for studying interactions, such as competition and mutualism, or lack of interaction between the different components of microbial communities and could be used to study their relative importance in biogeochemical fluxes.     

浙南海域腹泻性贝毒分析

在浙南海域共采集了10种贝类40份样品.运用高效液相色谱方法检测腹泻性贝毒,共检出 9份样品含有腹泻性贝毒.染毒样品检出的腹泻性贝毒(软海绵酸,OA)质量比为0.07～5.85 μg/g,共有7个样品含量超标,超标率为17.5%.无论是检出率还是超标率,都呈现夏季>春季>秋季的规律.浙南海域的南部腹泻性贝毒检出率和超标...     

2009年4月浙江近岸海域浮游植物的分布特征及与环境因子的关系

利用2009年4月在浙江近岸海域采集的47个浮游植物水样,对该海域浮游植物的类群组成及其空间分布特征进行了研究,并分析了其空间分布特征与环境因子的关系,结果表明:(1)共鉴定出浮游植物81种,隶属于4门32属,其中硅藻26属69种,甲藻4属10种,硅藻在种类数上占优势,中肋骨条藻Skeletonema costatum和具槽直链藻Melosira sulcata为优势种。(2)各水层浮游植物总细胞密度为(2~236.8)×102个/dm3,平均值为41.9×102个/dm3。平面分布上,表层和5 m层的浮游植物总细胞密度分布趋势较一致,即调查区域最南端出现高值区(>200×102个/dm3),沿岸向北则细胞密度值呈递减趋势。硅藻细胞密度为(1.2~236.4)×102个/dm3,平均值为40.88×102个/dm3,与浮游植物总细胞密度分布趋势基本一致。甲藻细胞密度为(0~13.6)×102个/dm3,平均值为0.94×102个/dm3。垂直分布上,浮游植物总细胞密度大小依次为30 m层(82.5×102个/dm3)>表层(35.3×102个/dm3)>10 m层(31.9×102个/dm3)>5 m层(31.8×102个/dm3)。断面分布上,浮游植物总细胞密度由大到小依次为D断面(83.1×102个/dm3)>C断面(36.5×102个/dm3)>B断面(30.9×102个/dm3)>A断面(16.3×102个/dm3)。(3)总体上,浮游植物生态分布与水温、营养盐均呈正相关关系。