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631.
A study of chemical and sedimentological parameters integrated with benthic foraminifera investigation was conducted along
the northern coast of Gabes Gulf. Thirty-two samples were studied and a total of 68 benthic foraminiferal species were identified.
Heavy metals enrichment factors and total hydrocarbon concentrations showed both metal and petrogenic pollution related mainly
to phosphogypsum, sewage, and fishing activities. Statistical analysis (bivariate correlation and hierarchical cluster analysis)
show a possible control of these pollutants on density, diversity, as well as the taxonomic composition of the benthic foraminiferal
assemblages. The extent to which the population was found less dense and less diversified corresponded to the degree to which
the sediment was contaminated. In these contaminated sites, an increase in relative abundance of opportunistic species such
Ammonia tepida and Haynesina germanica was found. Far from pollution, foraminiferal assemblages are dominated by species characteristic of Mediterranean shallow
water (Ammonia beccarii, Ammonia parkinsoniana, Elphidium crispum, Elphidium williamsoni, Elphidium advenum, Peneroplis planatus, Peneroplis pertesus). 相似文献
632.
Romo S Fernández F Ouahid Y Barón-Sola Á 《Environmental monitoring and assessment》2012,184(2):939-949
Cyanobacteria dominance and cyanotoxin production can become major threats to humans and aquatic life, especially in warm
shallow lakes, which are often dominated by cyanobacteria. This study investigates the occurrence and distribution of microcystins
(MCYST) in water, cell-bound and in the tissues of the commercial mugilid Liza sp. in the largest, coastal, Spanish Mediterranean lake (Albufera of Valencia). This is the first report concerning microcystin
accumulation in tissues of mugilid fish species. Considerable amounts of microcystins were found in the water and seston,
which correlated with development of Microcystis aeruginosa populations in the lake. The MCYST concentrations found in Lake Albufera (mean 1.7 and 17 μg/L and maximum 16 and 120 μg/L
in water and seston, respectively) exceeded by one to two orders of magnitude the guideline levels proposed by the World Health
Organization and were higher than that reported in other lakes of the Mediterranean zone. The presence of MCYST was found
in all the fishes studied and accumulated differently among tissues of the commercial species Liza sp. Toxin accumulation in fish tissues showed that although the target organ for MCYST was the liver, high concentrations
of microcystins were also found in other analysed tissues (liver>intestine>gills>muscle). Human tolerable daily intake for
microcystins is assessed relative to the WHO guidelines, and potential toxicological risks for humans, wildlife and related
ecosystems of the lake are discussed. 相似文献
633.
de Andrade Brito I Arruda Freire C Yamamoto FY Silva de Assis HC Rodrigues Souza-Bastos L Cestari MM de Castilhos Ghisi N Prodocimo V Filipak Neto F de Oliveira Ribeiro CA 《Journal of environmental monitoring : JEM》2012,14(2):615-625
Paraíba do Sul River is located at a very densely inhabited region of Brazil crossing the three most industrialized states of the country (S?o Paulo, Minas Gerais and Rio de Janeiro states). As a result, industrial and farming residues as well as urban sewage are frequently disposed without appropriate treatment. The current study aimed at investigating the water quality in three reservoirs along the Paraíba do Sul River (Ilha dos Pombos, Santa Cecília and Santa Branca), through physiological, morphological, biochemical, and genetic biomarkers. The bioindicator chosen was the catfish Pimelodus maculatus, sampled during the dry (June 2008) and rainy (February 2009) seasons. Also, some water physicochemical parameters were analyzed from the sampling sites, but displayed no alterations according to the Brazilian Agency for Water Quality Legislation. Branchial carbonic anhydrase activity was inhibited in the dry season, while renal carbonic anhydrase activity was inhibited in the rainy season in the Santa Branca reservoir, indicating disturbance of osmoregulatory and acid-base regulation processes. Histopathological alterations were observed in the gills (neoplasic and tissue hyperplasia processes) and liver (necrosis), indicating serious damage to the functional integrity of these organs. A high incidence of melanomacrophage centers was observed in the liver, suggesting an intense immune response in all reservoirs. Acetylcholinesterase and catalase activity showed also differences corroborating some morphological results. Likewise, the induction of the micronucleus and DNA damage indicate genotoxicity, but mainly in the Santa Branca reservoir. Thus, the health status of P. maculatus warrants caution in the use of the water from the 3 reservoirs for direct human consumption, particularly after the accidental spill of endosulfan in November 2008, three months before the rainy season sampling. 相似文献
634.
de-la-Ossa-Carretero JA Del-Pilar-Ruso Y Giménez-Casalduero F Sánchez-Lizaso JL 《Environmental monitoring and assessment》2012,184(4):2133-2149
Physicochemical characteristics of sediment and benthic communities were studied in the proximity of seven sewage outfalls
with differences in flow and wastewater treatment in the Western Mediterranean Sea. Redox potential was the only abiotic parameter
which showed a pattern related with distance to outfalls, whereas granulometry, percentage of organic matter, metal concentrations
or pH did not show changes related with outfall presence. Benthic community analysis proved to be the most suitable monitoring
tool. The results showed that the highest impacted stations corresponded with those closest to outfall with the highest flow
and only pre-treatment, whilst a decrease of this tendency was detected in the locations where secondary treatment takes place.
Meta-analysis showed a decrease of amphipods and tanaids abundance as well as redox potential, as the indicators with the
clearest response to sewage presence. 相似文献
635.
自然资源资产是具有商业或交换价值的自然环境要素,是人类生存与发展的基础。生态资产是自然资源资产的重要组成部分,提供各种产品和服务。以生态资产为研究对象,从存量和流量两个方面构建核算体系,并以上海市为案例,探讨了生态资产核算体系的核算方法,评价了上海市2013年的生态资产状况与价值总量。结果显示,存量核算方面,林地的质量等级主要为中,占林地总面积的45.62%;河流的质量等级主要为劣,占总长度的54.65%。2013年生态资产流量总价值量为5 002.76亿元,其中,直接产品价值为866.12亿元,间接服务价值为4 136.64亿元。结果表明,生态资产核算体系体现了生态资产对区域社会经济发展的支撑作用,可以用来定量评估和核算区域的生态资产状况及其变化特征,可以为区域的生态系统管理与绩效考核提供科学依据。 相似文献
636.
The effect of ambient air pollution with increased ozone concentrations on the feeding behaviour of the beech weevil Rhynchaenus fagi L. was studied. In a dual choice feeding test the beech weevil preferred leaf disks from beech saplings exposed to ambient air against those from filtered air in 65.5% of all cases. 相似文献
637.
Bellmore JR Baxter CV Ray AM Denny L Tardy K Galloway E 《Environmental management》2012,49(3):734-750
Pre-restoration studies typically focus on physical habitat, rather than the food-base that supports aquatic species. However,
both food and habitat are necessary to support the species that habitat restoration is frequently aimed at recovering. Here
we evaluate if and how the productivity of the food-base that supports fish production is impaired in a dredge-mined floodplain
within the Yankee Fork Salmon River (YFSR), Idaho (USA); a site where past restoration has occurred and where more has been
proposed to help recover anadromous salmonids. Utilizing an ecosystem approach, we found that the dredged segment had comparable
terrestrial leaf and invertebrate inputs, aquatic primary producer biomass, and production of aquatic invertebrates relative
to five reference floodplains. Thus, the food-base in the dredged segment did not necessarily appear impaired. On the other
hand, we observed that off-channel aquatic habitats were frequently important to productivity in reference floodplains, and
the connection of these habitats in the dredged segment via previous restoration increased invertebrate productivity by 58%.
However, using a simple bioenergetic model, we estimated that the invertebrate food-base was at least 4× larger than present
demand for food by fish in dredged and reference segments. In the context of salmon recovery efforts, this observation questions
whether additional food-base productivity provided by further habitat restoration would be warranted in the YFSR. Together,
our findings highlight the importance of studies that assess the aquatic food-base, and emphasize the need for more robust
ecosystem models that evaluate factors potentially limiting fish populations that are the target of restoration. 相似文献
638.
It is commonly put forward that effective uptake of research in policy or practice must be built upon a foundation of active knowledge exchange and stakeholder engagement during the research. However, what is often lacking is a systematic appreciation of the specific practices of knowledge exchange and their relative merits. The paper reports on a 2009 survey of 21 research projects within the UK Research Councils' Rural Economy and Land Use Programme regarding the involvement and perceived impact of over a thousand stakeholders in the research. The survey reveals that most stakeholders were involved as research subjects or as event participants. Large numbers were also engaged in the research process itself, including involvement in shaping the direction of research. Stakeholder engagement is perceived as bringing significant benefits to the process of knowledge production. A close relationship is found between mechanisms and approaches to knowledge exchange and the spread of benefits for researchers and stakeholders. Mutual benefits are gained from exchange of staff or where stakeholders are members of research advisory groups. Different stakeholder sectors are also associated with different patterns of engagement, which lead to contrasting impact patterns. Any efforts to alter knowledge exchange processes and outcomes must overcome these differing engagement tendencies. Overall, much greater attention should be given to early processes of knowledge exchange and stakeholder engagement within the lifetime of research projects. 相似文献
639.
Siotto M Sezenna E Saponaro S Innocenti FD Tosin M Bonomo L Mezzanotte V 《Journal of environmental management》2012,93(1):31-37
In modern intensive agriculture, plastics are used in several applications (i.e. mulch films, drip irrigation tubes, string, clips, pots, etc.). Interest towards applying biodegradable plastics to replace the conventional plastics is promising. Ten monomers, which can be applied in the synthesis of potentially biodegradable polyesters, were tested according to ASTM 5988-96 (standard respirometric test to evaluate aerobic biodegradation in soil by measuring the carbon dioxide evolution): adipic acid, azelaic acid, 1,4-butanediol, 1,2-ethanediol, 1,6-hexanediol, lactic acid, glucose, sebacic acid, succinic acid and terephthalic acid. Eight replicates were carried out for each monomer for 27-45 days. The numerical code AQUASIM was applied to process the CO? experimental data in order to estimate values for the parameters describing the different mechanisms occurring to the monomers in soil: i) the first order solubilization kinetic constant, K(sol) (d?1); ii) the first order biodegradation kinetic constant, K(b) (d?1); iii) the lag time in biodegradation, t(lag) (d); and iv) the carbon fraction biodegraded but not transformed into CO?, Y (-). The following range of values were obtained: [0.006 d?1, 6.9 d?1] for K(sol), [0.1 d?1, 1.2 d?1] for K(b), and [0.32-0.58] for Y; t(lag) was observed for azelaic acid, 1,2-ethanediol, and terephthalic acid, with estimated values between 3.0 e 4.9 d. 相似文献
640.
Terer T Muasya AM Dahdouh-Guebas F Ndiritu GG Triest L 《Journal of environmental management》2012,93(1):71-84
The current study documented local utilization of Cyperus papyrus L. (papyrus), harvesting patterns, threats, and local management practices among the Endorois community living around Loboi swamp (Kenya). Papyrus is a highly productive freshwater macrophyte that is widely utilized throughout tropical Africa. However, increased human population and poverty, has led to over exploitation and conversion of papyrus wetlands to agricultural fields. Nonetheless, users of papyrus hold important local ecological knowledge (LEK) and practices. We show that Endorois practices on papyrus uses are compatible with the management priorities of the swamp and a wider conservation framework using data obtained from three focus group discussions (FGD), interviews of 34 households and 15 key informants. The study revealed that papyrus support local livelihood notably as a source of income (papyrus mats are sold), cattle fodder, roofing materials (shelter), and cooking fuel. The study further revealed important LEK relating to harvesting patterns, recovery after harvesting and traditional management practices. Correlation and principal component analyses showed that experienced old harvesters (EXPERT) avoided harvesting repeatedly at the same location (REVISIT), thereby allowing recovery of papyrus when compared to younger harvesters (r = 0.63, p < 0.01). However, over 70% of harvesters predicted a decrease in papyrus coverage in the future due to the current diversion of water from the swamp, and frequent droughts, despite the instituted traditional management strategies (e.g. rotational harvesting) to curb overharvesting. The study concluded that the documentation of site-scale papyrus users' profile, LEK, and traditional practices are vital for the conservation and management of Loboi swamp. 相似文献