Use of seaweeds for monitoring trace elements in coastal waters

Concentrations of a wide range of trace elements: arsenic, cadmium, cobalt, chromium, hafnium, nickel, thorium, uranium, zinc and the rare earth elements, cerium, europium, samarium, terbium and ytterbium were determined by instrumental neutron activation analysis in the brown alga,Fucus vesiculosus from Eckwarder Hörne, North Sea and from Rügen, Baltic Sea. Another brown alga,Sargassum filipendula from Sri Lanka, Indian ocean (representing an unpolluted control station) was similarly investigated. Cobalt, chromium and nickel concentrations were highest inF. vesiculosus from the North Sea while zinc was highest in samples from the Baltic Sea, reflecting high levels of these elements in coastal waters of the North and the Baltic sea. Cadmium, cobalt, nickel and zinc levels were lowest inS. filipendula from Sri Lanka, probably demonstrating lower levels of those elements in coastal waters. Concentration levels of hafnium, thorium, uranium, and the rare earth elements were highest inS. filipendula. Two years later in 1994,S. filipendula along withUlva sp. (green alga) was resampled from the same sampling site, and in addition to the above elements, six other trace elements (Ag, Ba, Br, Rb, Se and Sr) were determined.Sargassium filipendula showed a particular affinity for Ag, As, Br and Sr. For the other elements, marginal concentration differences were observed betweenS. filipendula andUlva sp., probably reflecting the regional background levels. Substantially higher concentrations of Hf, Th, U, and the rare earths were found again in the 1994Sargassum andUlva samples, reflecting the effect of a substrate rich in rare earth elements. The brown algae used in this study may be used to monitor trace elements in coastal waters.     

Feeding ecology of the mangrove crab <Emphasis Type="Italic">Ucides cordatus</Emphasis> (Ocypodidae): food choice,food quality and assimilation efficiency

Food preferences, consumption rates and dietary assimilation related to food quality were investigated for the large semi-terrestrial and litter-consuming mangrove crab Ucides cordatus cordatus (Ocypodidae, L. 1763) in northern Brazil. Stomach contents were composed of mangrove leaves (61.2%), unidentified plant material and detritus (28.0%), roots (4.9%), sediment (3.3%), bark (2.5%), and animal material (0.1%). U. cordatus prefers Rhizophora mangle over Avicennia germinans leaves despite a higher nitrogen content, lower carbon to nitrogen (C/N) ratio and lower tannin content of the latter. Also, assimilation rates for senescent R. mangle leaves (C: 79.3%, N: 45.4%) were higher than for A. germinans leaves (C: 40.6%, N: 9.1%). Faeces composition indicates that A. germinans leaves were more difficult to masticate and digest mechanically. The leaf-ageing hypothesis, according to which crabs let leaves age in burrows to gain a more palatable and nutritive food, was rejected for U. cordatus since N content, C/N ratio and the abundance of microorganisms did not differ significantly between senescent leaves and leaves taken from burrows. The low microbial biomass on leaf surfaces and in the sediment indicates its minor importance for the nutrition of U. cordatus. It is concluded that high ingestion and assimilation rates of a R. mangle diet together with the consumption of algae allow for a high intake of C, N, and energy. The data suggest that the digestibility of mangrove leaves by U. cordatus is not hampered by tannins. This may have provided a competitive advantage over other leaf-consuming invertebrates unable to digest mangrove litter with high tannin concentrations. Due to the large stock biomass of U. cordatus in the study area, a great amount of finely fragmented faeces is produced (about 7.1 ton dry matter ha⁻¹ year⁻¹ in a R. mangle forest) which is enriched in C, N and bacterial biomass compared to the sediment. The decomposition of mangrove litter, and thus nutrient and energy transfer into the sediment, is greatly enhanced due to litter processing by U. cordatus.     

Using Dynamic Modeling to Scope Environmental Problems and Build Consensus

/ This paper assesses the changing role of dynamic modeling for understanding and managing complex ecological economic systems. It discusses new modeling tools for problem scoping and consensus building among a broad range of stakeholders and describes four case studies in which dynamic modeling has been used to collect and organize data, synthesize knowledge, and build consensus about the management of complex systems. The case studies range from industrial systems (mining, smelting, and refining of iron and steel in the United States) to ecosystems (Louisiana coastal wetlands, and Fynbos ecosystems in South Africa) to linked ecological economic systems (Maryland's Patuxent River basin in the United States). They illustrate uses of dynamic modeling to include stakeholders in all stages of consensus building, ranging from initial problem scoping to model development. The resultant models are the first stage in a three-stage modeling process that includes research and management models as the later stages.KEY WORDS: Dynamic modeling; Scoping; Consensus building; Environmental management; Ecosystem management; Policy making; Graphical programming languages     

Batch methanogenic fermentation experiments of wastewater from a brown coal low-temperature coke plant

Coke plant effluents with high contents of organic compounds are mainly treated by biological aerobic fermentation after physical pre-treatment.In this study,a brown coal condensate wastewater from a low temperature coking process was fermented under methanogenic conditions in discontinuous experiments.By this fermentation,acetate,propionate,and the main polyphenolic compounds(catechol,resorcinol and hydroquinone) were degraded to a level below the detection limit.The COD was reduced by 72% with a residual ...     

An integrated approach to mangrove dynamics and management

The main objective of the MADAM project (Mangrove Dynamics and Management) is to generate the scientific basis enabling the sustainable stewardship of the resources of the Caeté mangrove estuary in Northeast Brazil in the sense of integrated coastal (zone) management. To achieve this, it is necessary to acquire in-depth knowledge of natural processes as well as of the relevant institutional, cultural, economic, social and political dynamics. Causal linkages within the ecosystem, as well as between ecosystem, economy and society, are analysed and explained via dynamic and trophic modelling. Scenario construction is intended to forecast the effects of acute or chronic interference on utilized resources, and to answer wider, management-related questions (e.g. restoration of destroyed areas, utilization potential for aquaculture). This paper describes the project strategy as developed and modified in the context of research results from the initial 2-yr project phase. It is argued that a continuous discussion process is essential to assess the validity of the strategies formulated at the beginning of a medium-time project, particularly if the project is of interdisciplinary nature.     

Large males dominate: ecology,social organization,and mating system of wild cavies,the ancestors of the guinea pig

Ecological factors differently affect male and female animals and thereby importantly influence their life history and reproductive strategies. Caviomorph rodents are found in a wide range of habitats in South America and different social and mating systems have evolved in closely related species. This permits to study the impact of ecological factors on social evolution. In this study, we investigated the social organization and the mating system of the wild cavy (Cavia aperea), the ancestor of the domestic guinea pig, in its natural habitat in Uruguay. Based on our laboratory investigations, we expected a polygynous system with large males controlling access to females. Results from radiotelemetry and direct observations showed that females occupied small stable home ranges which were largely overlapped by that of one large male, resulting in a social organization of small harems. In some cases, small satellite males were associated with harems and intermediate-sized roaming males were occasionally observed on the study site. However, microsatellite analyses revealed that offspring were exclusively sired by large males of the same or neighboring harems, with a moderate degree of multiple paternity (13–27%). Thus, the mating system of C. aperea can be described as polygynous and contrasts with the promiscuous organization described for other species of cavies (Cavia magna, Galea musteloides and Microcavia australis) living under different ecological conditions. Our findings stress the strong impact of environmental factors on social evolution in Caviomorphs as resource distribution determines female space use and, thereby, the ability of males to monopolize females. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Reproductive health services for refugees by refugees: an example from Guinea

The need to involve refugees in their own reproductive health (RH) services has long been recognised, but there is a lack of published examples describing how this can be achieved collaboratively between refugee initiatives, UNHCR, bilateral development organisations and international relief agencies. This paper outlines the work, outputs and lessons learnt of the Reproductive Health Group (RHG), an organisation of Liberian and Sierra Leonean refugee midwives and laywomen providing RH services to fellow refugees in Guinea's Forest Region between 1996 and 2000. Working as part of the Guinean health system, RHG midwives and community facilitators helped make the RH services in their region the most effective in Guinea at the time. Looking at RHG's achievements, the challenges it faced and partly overcame, it is argued that refugee organisations can plan and implement RH services for refugees where UNHCR and its international partners ensure that they receive funding and technical assistance.     

Wet deposition of poly- and perfluorinated compounds in Northern Germany

Twenty precipitation samples were taken concurrently with air samples at a northern German monitoring site over a period of 7 months in 2007 and 2008. Thirty four poly- and perfluorinated compounds (PFC) were determined in rain water samples by solid phase extraction and HPLC-MS/MS analysis. Seventeen compounds were detected in rain water with ΣPFC concentrations ranging from 1.6 ng L⁻¹ to 48.6 ng L⁻¹. Perfluorooctanoate (PFOA) and perfluorobutanate (PFBA) were the compounds that were usually observed in highest concentrations. Calculated ΣPFC deposition rates were between 2 and 91 ng m⁻² d⁻¹. These findings indicate that particle phase PFC are deposited from the atmosphere by precipitation. A relationship between PFC wet deposition and air concentration may be established via precipitation amounts. Trajectory analysis revealed that PFC concentration and deposition estimates in precipitation can only be explained if a detailed air mass history is considered.     

Exposure patterns of UV filters, fragrances, parabens, phthalates, organochlor pesticides, PBDEs, and PCBs in human milk: correlation of UV filters with use of cosmetics

In order to assess potential risks of exposure to environmental chemicals, more information on concomitant exposure to different chemicals is needed. We present data on chemicals in human milk of a cohort study (2004, 2005, 2006) of 54 mother/child pairs, where for the first time, cosmetic UV filters, synthetic musks, parabens and phthalate metabolites were analyzed in the same sample along with persistent organochlor pollutants (POPs), i.e., organochlor pesticides and metabolites, polybrominated diphenylethers and polychlorinated biphenyls (PCBs). The two groups of chemicals exhibited different exposure patterns. Six out of seven PCB congeners and a majority of pesticides were present in all milk samples, with significant correlations between certain PCB congener and pesticide levels, whereas the cosmetic-derived compounds, UV filters, parabens and synthetic musks, exhibited a more variable exposure pattern with inter-individual differences. UV filters were present in 85.2% of milk samples, in the range of PCB levels. Comparison with a questionnaire revealed a significant correlation between use of products containing UV filters and their presence in milk for two frequently used and detected UV filters, 4-methylbenzylidene camphor and octocrylene, and for the whole group of UV filters. Concentrations of PCBs and organochlor pesticides were within ranges seen in Western and Southern European countries. For several POPs, mean and/or maximum daily intake calculated from individual concentrations was above recent US EPA reference dose values. Our data emphasize the need for analyses of complex mixtures to obtain more information on inter-individual and temporal variability of human exposure to different types of chemicals.     

Air pollution modeling at road sides using the operational street pollution model--a case study in Hanoi, Vietnam

In many metropolitan areas, traffic is the main source of air pollution. The high concentrations of pollutants in streets have the potential to affect human health. Therefore, estimation of air pollution at the street level is required for health impact assessment. This task has been carried out in many developed countries by a combination of air quality measurements and modeling. This study focuses on how to apply a dispersion model to cities in the developing world, where model input data and data from air quality monitoring stations are limited or of varying quality. This research uses the operational street pollution model (OSPM) developed by the National Environmental Research Institute in Denmark for a case study in Hanoi, the capital of Vietnam. OSPM predictions from five streets were evaluated against air pollution measurements of nitrogen oxides (NO(x)), sulfur dioxide (SO2), carbon monoxide (CO), and benzene (BNZ) that were available from previous studies. Hourly measurements and passive sample measurements collected over 3-week periods were compared with model outputs, applying emission factors from previous studies. In addition, so-called "backward calculations" were performed to adapt the emission factors for Hanoi conditions. The average fleet emission factors estimated can be used for emission calculations at other streets in Hanoi and in other locations in Southeast Asia with similar vehicle types. This study also emphasizes the need to further eliminate uncertainties in input data for the street-scale air pollution modeling in Vietnam, namely by providing reliable emission factors and hourly air pollution measurements of high quality.