漂白粉和敌百虫对净化养鱼水生物膜活性的影响

以附着在固体表面的生物膜为材料,实验研究了渔药漂白粉和敌百虫对其菌类数量及活性的影响。通过分析生化需氧量(BOD5)的曲线,测定实验前后细菌、放线菌、真菌的数量和水中化学需氧量(CODMn)、铵氮(NH+4-N)的质量浓度,并用电子显微镜观察。结果表明:ρ(漂白粉)小于6 17mg L,生物膜的活性能够恢复;ρ(漂白粉)为0 7mg L时,15d后生物膜的活性可恢复80%以上。在实验浓度范围内,虽然敌百虫对生物膜的活性和水质净化能力影响不明显,但也应谨慎使用以防止污染环境。      

漂白废水中有机氯在湿地土壤中的环境行为

在实验室模拟条件下,研究了漂白废水中有机氯在土壤中的吸附平衡规律和土柱中的迁移特性,同时分析了某造纸废水长期灌溉湿地土壤的可提取有机氯分布特征.结果表明,可吸附有机氯在土壤中的吸附规律符合Freundlich等温式,且在未受灌溉土壤和已灌溉2a土壤中的吸附常数分别为7.341 0和4.950 1,非线性程度常数分别为0.502 4和0.610 8;经漂白废水淋溶的土柱渗滤液中有较多的可吸附有机氯(AOCl)检出,废水中的有机氯被土壤大量的吸附,且在表层中含量最高.经过造纸废水灌溉1、2和3a后的土壤表层可提取有机氯(EOCl)的平均含量分别为4.48、10.35和10.07μg/g,与土壤背景值相比有明显的提高.     

造纸漂白废水中多氯联苯的测定

介绍了造纸氯化漂白废水中痕量多氯联苯的测定方法,采用国产ＧＤＸ－５０１树脂进行富集,经素氏提取,浓硫酸洗涤和去活化的氧化铝－硝酸银硅胶层析柱净化后,用毛细管气相色谱法测定,实验结果表明,造纸氯化漂白废水中产生的ＰＣＢｓ为１０＾－９级,且以低氯取代产物为主,方法回收率在６０％以上。     

A Strategic Framework for Responding to Coral Bleaching Events in a Changing Climate

The frequency and severity of mass coral bleaching events are predicted to increase as sea temperatures continue to warm under a global regime of rising ocean temperatures. Bleaching events can be disastrous for coral reef ecosystems and, given the number of other stressors to reefs that result from human activities, there is widespread concern about their future. This article provides a strategic framework from the Great Barrier Reef to prepare for and respond to mass bleaching events. The framework presented has two main inter-related components: an early warning system and assessment and monitoring. Both include the need to proactively and consistently communicate information on environmental conditions and the level of bleaching severity to senior decision-makers, stakeholders, and the public. Managers, being the most timely and credible source of information on bleaching events, can facilitate the implementation of strategies that can give reefs the best chance to recover from bleaching and to withstand future disturbances. The proposed framework is readily transferable to other coral reef regions, and can easily be adapted by managers to local financial, technical, and human resources.     

The condition of coral reefs in South Florida (2000) using coral disease and bleaching as indicators

The destruction of coral reef habitats has occurred at unprecedented levels during the last three decades. Coral disease and bleaching in the Caribbean and South Florida have caused extensive coral mortality with limited recovery, often coral reefs are being replaced with turf algae. Acroporids were once dominant corals and have diminished to the state where they are being considered as endangered species. Our survey assessed the condition of reef corals throughout South Florida. A probability-based design produced unbiased estimates of the spatial extent of ecological condition, measured as the absence or presence and frequency or prevalence of coral diseases and bleaching intensity over large geographic regions. This approach allowed us to calculate a quantifiable level of uncertainty. Coral condition was estimated for 4100 hectares (ha) (or 41.0 km²) of coral reefs in South Florida, including reefs in the Florida Keys National Marine Sanctuary (FKNMS), New Grounds, Dry Tortugas National Park (DTNP), and Biscayne National Park (BNP). The absence or presence of coral disease, causal coral bleaching, partial bleaching and coral paling were not good indicators of overall coral condition. It was more useful to report the prevalence of anomalies that indicated a compromised condition at both the population and community levels. For example, 79% of the area in South Florida had less than 6% of the coral colonies diseased, whereas only 2.2% (97.15 ha) of the sampled area had a maximum prevalence of 13% diseased coral colonies at any single location. The usefulness of causal bleaching might be more important when considering the prevalence of each of the three different states at a single location. For example, paling was observed over the entire area, whereas bleaching and partial bleaching occurred at 19 and 41% of the area, respectively. An index for coral reef condition might integrate the prevalence and species affected by each bleaching state at individual locations. By establishing these baselines, future surveys can examine changes and trends in the spatial distribution of coral conditions in South Florida and able to score the reefs as to their health status.     

草制浆造纸中段废水处理及回用技术分析研究

中段废水是制浆造纸工业的主要污染源之一，从工程设计的角度出发，对草制浆造纸中段废水处理及回用提出一套可行适用的工艺方案；对主要工艺环节参数、设备备有说明，以供同行借鉴。     

Natural and anthropogenic influences on the diversity structure of reef fish communities in the Tuamotu Archipelago (French Polynesia)

Despite the rapid rate of human-induced species losses, the relative influence of natural and anthropogenic factors on the functional diversity of species assemblages remains unknown for most ecosystems. A model was previously developed to predict the diversity structure of coral reef fish assemblages in 10 atolls of low human pressure and contrasting morphology of the Tuamotu Archipelago (French Polynesia). This existing model predicted smoothed histograms (spectra) of species richness according to size classes, diet classes and life-history classes of fish assemblages using a combination of environmental characteristics at different spatial scales. The present study applied the model to Tikehau, another atoll of the same archipelago where commercial fishing is practiced and where the same sampling strategy was reproduced. Significant differences appeared between predicted and observed species richness in several size, diet and life-history classes of fish assemblages in Tikehau. Two parameters which were not accounted for in the initial model, i.e. fishing pressure and atoll position within the archipelago, explained together 63% of variance in model residuals, >60% being explained by fishing pressure only. The respective effects of fishing and atoll position on the diversity of coral reef fish assemblages are discussed, with the potential of such modelling approach to assess the relative importance of factors affecting functional diversity within communities.     

Allowing macroalgae growth forms to emerge: Use of an agent-based model to understand the growth and spread of macroalgae in Florida coral reefs,with emphasis on Halimeda tuna

The growth patterns of macroalgae in three-dimensional space can provide important information regarding the environments in which they live, and insights into changes that may occur when those environments change due to anthropogenic and/or natural causes. To decipher these patterns and their attendant mechanisms and influencing factors, a spatially explicit model has been developed. The model SPREAD (SPatially-explicit Reef Algae Dynamics), which incorporates the key morphogenetic characteristics of clonality and morphological plasticity, is used to investigate the influences of light, temperature, nutrients and disturbance on the growth and spatial occupancy of dominant macroalgae in the Florida Reef Tract. The model species, Halimeda and Dictyota spp., are modular organisms, with an “individual” being made up of repeating structures. These species can also propagate asexually through clonal fragmentation. These traits lead to potentially indefinite growth and plastic morphology that can respond to environmental conditions in various ways. The growth of an individual is modeled as the iteration of discrete macroalgal modules whose dynamics are affected by the light, temperature, and nutrient regimes. Fragmentation is included as a source of asexual reproduction and/or mortality. Model outputs are the same metrics that are obtained in the field, thus allowing for easy comparison. The performance of SPREAD was tested through sensitivity analysis and comparison with independent field data from four study sites in the Florida Reef Tract. Halimeda tuna was selected for initial model comparisons because the relatively untangled growth form permits detailed characterization in the field. Differences in the growth patterns of H. tuna were observed among these reefs. SPREAD was able to closely reproduce these variations, and indicate the potential importance of light and nutrient variations in producing these patterns.     

Spatial dynamics and substrate impacts of recreational snorkelers and SCUBA divers in Hawaiian Marine Protected Areas

We quantified spatial dynamics and substrate impacts of snorkelers and SCUBA divers within four Hawaiian MPAs to determine: (1) whether coral reefs in these areas are being damaged by recreational activities, and (2) how damage might be mitigated. Observers secretly followed snorkelers and SCUBA divers, and used handheld Global Positioning System (GPS) units to record their geographic tracks and substrate contacts. Most activities occurred within relatively small, well-defined areas associated with access points. Despite heavy use, recreation impact was low at Hawaiian MPAs because most fragile corals occurred below the maximum depth of the dominant recreational activity (snorkeling). SCUBA diving was only common at one MPA with physically durable benthic habitats. GPS tracking provided useful insights into how recreational impacts to MPAs could be reduced. General topography could be used to predict where visitors will go, and designated access points could be used to focus substrate contact away from fragile habitats.