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天津典型湿地地表水环境质量分析与评价 总被引:1,自引:0,他引:1
采用单因子污染指数法,以天津典型湿地即七里海、北大港、团泊洼和大黄堡湿地为研究对象,根据枯水期和丰水期的监测结果,对其水环境质量进行分析与评价,结果表明:4个湿地水质的pH、As、Cd、Pb浓度较低,均能达到《地表水环境质量标准》I类标准要求;除团泊洼外,其他湿地水体的铬浓度均能达到《地表水环境质量标准》II类标准;而COD、总氮、总磷和汞浓度含量较高,远高于《地表水环境质量标准》V类标准;湿地外围河流如七里海湿地的潮白新河,团泊洼湿地的独流咸河与大邱庄排污河,北大港窑地桥污水河等多为排污河,水质很差,这些外围河流对湿地的水环境质量影响较大。 相似文献
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今年第22号台风“黑格比”在菲律宾登陆后于8日早晨5时减弱为强热带风暴,8日下午5时,其中心位于菲律宾中部,就是北纬13.3度、东经1216度,中心附近最大风力有11级(30米/秒),中心最低气压980百帕。七级风圈半径100~310公里,十级风圈半径60~100公里。预计,“黑格比”将于9目白天以强热带风暴级别(10级)移入南海中南部海面,进入南海后,继续西移,11日到12日趋向越南南部沿海; 相似文献
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《江苏科技大学学报(社会科学版)》2021,35(2)
DNA条形码技术在物种快速鉴定与种群遗传分化等方面发挥着重要作用,但目前基于DNA条形码技术针对中国襀翅目昆虫的研究尚未见报道.本研究利用生物信息学方法在基因数据库中获取中国襀翅目DNA条形码序列42条.通过碱基组成分析发现,条形码序列具有A和T碱基偏好性,同时具有较多的保守序列位点.基于DNA条形码序列的系统进化分析表明,DNA条形码在种级和属级水平具有较好的鉴定能力,为进一步利用DNA条形码技术全面研究中国襀翅目昆虫奠定了基础. 相似文献
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<正>从天津新区商务委获悉,日前,天津港博物馆等3个新区特色景区通过国家3A级景区评审。截至目前,新区共有A级景区7家,占全市的10%,其中4A级1家,3A级5家,2A级1家。此次通过国家3A级景区评审的特色景区分 相似文献
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<正>日本的3·11地震引发了福岛核电站的核泄漏事故。4月5日,福岛第一核电站向太平洋排放1万多t污水,放射性物质含量是法定标准的500倍。4月12日,日本政府将福岛核泄漏事故提高到7级。日本核污染除了通过大气和海洋影响其他国家和地区外,还可能在海运中通过船舶、集 相似文献
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江苏省是我国东部沿海省份,具有沿海、长和京杭运河“二纵一横”3条国家水运主通道集,八方通衢的地域优势。全省水运资源十分富,拥有1175公里长江岸线(含江心洲),近000公里海岸线资源和690公里京杭运河。全内河航道里程达2.5万公里,拥有5个国家沿主要港口和2个内河主要港口。是 相似文献
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阜阳水系综合治理项目包含颍河凤凰湿地建设,凤凰湿地在颍河边滩布置挺水植物和沉水植物等,形成边滩植被水流的形态。通过由实验室实测数据验证过的边滩双层植被(分别模拟挺水植物、沉水植物)的流速分布解析解,推求颍河凤凰湿地的流速分布。结合流速分布结果,对工程的防冲设计进行验证,为边滩生态湿地项目的设计提供了边滩植被水流计算方法。 相似文献
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The Mediterranean ichthyofauna is composed of 652 species belonging to 405 genera and 117 families. Among these, 182 were studied for their parasitic copepods. The analysis of all the works conducted on these crustacea yielded 226 species distributed in 88 genera and 20 families. For each fish species we have established a file providing the species name of the fish, its family, its geographical distribution within the Mediterranean and some of its bio-ecological characteristics. Within each file, all the parasitic copepod species reported on each host species were listed. This allowed to know the species richness (SR) of these hosts. We thus produced 182 files within which 226 copepod species are distributed. A program was created under the Hypercard software, in order to analyse our data. Two parameters were studied. The first one is the mean species richness (MSR), which corresponds to the mean of the different SR found on the different host species. The second is the parasite–host ratio (P/H), which is the ratio of the number of copepod species by the number of host species. These parameters are calculated by our program for all the 182 species of Mediterranean fishes retained in our investigation, on the first hand, and, on the second hand, for one particular group of fish species. We used the following variables to investigate their correlations with copepod species richness: taxonomy—fish families, genera and species; biometry—maximal size of the adult fish; eco-ethology—mode of life (benthic, pelagic or nectonic), displacements (sedentary, migratory with environmental change, or migratory without environmental change), behaviour (solitary or gregarious). Other variables (colour, food, reproduction, abundance, distribution area) were also analysed but did not reveal any clear correlation. Providing that our study does not rely on quantitative (prevalence, intensity) but qualitative basis our aim was only to reveal some tendencies. These tendencies are as follows: (1) In many cases, parasite and host phylogeny seem to play an important role. There are fish families with copepods and families with few species of these parasites. The phyletic constraints could be due to the morphological characteristics of the habitat (e.g. structure of the gills) or biological/ecological characteristics that we were unable to identify. (2) It appears that the presence in a same environment of related fish species (e.g. several species of the same genus, or numerous genera of the same family) is correlated with high parasite richness. A likely explanation is that such situations favours alternated processes of lateral transfers and speciation. (3) Some eco-ethological criteria seem to favour the establishment of a large parasite species richness. It should be noted for instance that Mediterranean fishes the most often infected with copepods are generally nectonic or pelagic, migratory, and gregarious species. 相似文献
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Geoffrey A. Boxshall 《Journal of Marine Systems》1998,15(1-4)
Parasitic copepods belonging to two orders, Siphonostomatoida and Poecilostomatoida, are frequently reported from fish hosts in the deep sea. Three families of copepods are most commonly encountered, Sphyriidae, Lernaeopodidae and Chondracanthidae, but members of another four families, Hatschekiidae, Pennellidae, Philichthyidae and Hyponeoidae, are occasionally recorded. These parasites utilise various deep demersal fishes as hosts, especially species of the most abundant families, Macrouridae, Moridae, Synaphobranchidae and Alepocephalidae. Host specificity levels are variable, as for shallow-water fishes. In contrast, few parasites are regularly reported from fishes inhabiting the pelagic water column away from the bottom and away from the near-surface zone. Only the pennellids Sarcotretes scopeli and Cardiodectes medusaeus appear common on pelagic fishes, in the Atlantic and Pacific respectively. Host specificity levels in these two pennellid species are relatively low. It is speculated that the difficulty of encountering a host in the vast pelagic biome has restricted the diversity of parasitic copepods that have successfully colonized pelagic fishes. 相似文献
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M. J. Kingsford S. Becken C. Bordehore V. L. Fuentes K. A. Pitt A. A. Yangihara 《Coastal management》2018,46(1):1-18
A global challenge is dealing with the risk of envenomation by the stinging jellyfish. Those who are affected include: the people stung, tourist providers; diving and adventure operations, beach and park authorities, life guards, commercial marine operators as well as local and centralized government; we focus on tourism. There is a diversity of jellyfish that pose a risk and they vary greatly in their ecology. Here, we propose five eco-groups of jellyfish to assist in prioritizing estimates of the risks to a broad clientele. Eco-groups are: (1) “Pulse species” that impact on beaches for short well-defined periods; (2) “Shelf-wide species;” (3) “Nearshore species;” (4) “Drifter species” and (5) “Deep sea species.” Great spatial variation and strong seasonality in the occurrence and abundance of jellyfish is the rule, rather than the exception, and this indicates that local knowledge and preventative action is the key to reducing the risk of envenomation. Managers can take control by getting involved in: predicting risk, detecting the presence of jellyfish and advising on/or providing barriers and protection, first responses and treatment of sting victims. Good communication and record keeping is critical within the stakeholder chain. 相似文献
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以1 km通榆河为试验地,分别实施5种方案:1)在塌陷处移栽植物(芦苇、茭白、杞柳);2)植物移栽+外侧防护(木、竹混合栅栏);3)植物移栽+外侧防护+回填泥土;4)芦苇种子播种+外侧防护+回填土;5)以坍塌的裸露岸坡为空白对照,探讨几种混合型生态修复方式在通榆河岸坡防护中的实际效果。结果表明,在通榆河岸坡移栽芦苇和茭白、扦插杞柳是可行的,但需要在移栽区域的外侧进行适当的机械防护。移栽植物后多种本土植物的大量迁入形成具有高覆盖度的次生群落。本研究中的几种方案都显著降低岸坡坍塌速度,其中,方案3效果最佳。与传统方式相比,这种有机械保护的岸坡生态防护方式具有很好的经济效益。 相似文献
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N. A. SLOAN 《Coastal management》2013,41(2):129-143
Marine invertebrate species have usually been overlooked in favor of high-profile vertebrate species for facilitating dialogue towards area conservation. The northern abalone (Haliotis kamtschatkana) is proposed as a focal ("flagship") species whose protection and recovery could concentrate public concern for abalone and its associated kelp forest ecosystems in Haida Gwaii (Queen Charlotte Islands), British Columbia. I explain how issues of culture, commerce, and conservation unite to create a strong role for northern abalone in preparations for creating a large marine conservation area within Haida Gwaii. Culture is relevant, as local indigenous people (the Haida) are currently denied access to constitutionally established subsistence fishing rights for northern abalone. Commerce is involved as ongoing kelp forest-associated fisheries co-occur with northern abalone. Finally, this is a challenging precedent in Canadian marine conservation, as restoring two "listed" species- at risk (northern abalone and their predator, the sea otter (Enhydra lutris)) is potentially mutually exclusive. As part of the forthcoming public consultations towards establishing a marine conservation area, the opportunity provided by northern abalone to focus ideas and values should be seized. 相似文献
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Link22-北约国家的下一代战术数据链 总被引:6,自引:2,他引:4
Link-22是“北约改进Link-11”(NILE)定义的新型战术数据链,一种抗电子干扰、保密可靠、灵活机动的超视距数字数据通信系统,以便最终取代Link-11和补充完善Link-16。其目的是增加战术数据传输时间和传输高优先权的报警及作战命令,改进盟军互操作能力和增强指挥作战能力。 相似文献
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Few marine phytoplankton have heteromorphic life cycles and also often dominate the ecosystems in which they occur. The class Prymnesiophyceae contains a notable exception: the genus Phaeocystis includes three species that form gelatinous colonies but also occur within their ranges as solitary cells. Phaeocystis antarctica and P. pouchetii are exclusively high latitude taxa, and are notable for regionally tremendous blooms of the colony stage. P. globosa occurs circumglobally, yet its colony blooms primarily are confined to colder waters within its range. Three additional species are warm water forms that have been reported only as solitary cells or loose aggregations that bear little resemblance to the organized colonies of the other taxa. Interpretation of existing data indicates that resource availability (light, temperature and nutrients) by itself is not sufficient to explain this distinction between cold-water colony-forming taxa and warm water solitary cell taxa, nor why colony development in P. globosa is essentially a spatially restricted phenomenon within a much broader geographic range. Colony development by P. globosa in situ has been observed at temperatures ≥20 °C, but only rarely and generally under conditions of seasonally or anthropogenically elevated nutrient supply. Data presented here demonstrate colony development at 20–22 °C in natural plankton communities from oligotrophic waters that were pre-screened through 63 μm mesh (i.e. lacking mesozooplankton and large microzooplankton), but not in unscreened communities containing microzooplankton and >63 μm zooplankton. Reduction of colony proliferation at higher temperatures by mesozooplankton grazing remains as an intriguing possibility that is consistent with available evidence to help explain differences in latitudinal extent of in situ colony development. These data are interpreted within a theoretical framework regarding the potential advantages and disadvantages of the two life cycle stages. 相似文献
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Protist abundance and taxonomic composition were determined in four development stages of newly formed sea ice (new ice, nilas, young ice and thin first-year ice) and in the underlying surface waters of the Canadian Beaufort Sea from 30 September to 19 November 2003. Pico- and nanoalgae were counted by flow cytometry whereas photosynthetic and heterotrophic protists ≥ 4 µm were identified and counted by inverted microscopy. Protists were always present in sea ice and surface water samples throughout the study period. The most abundant protists in sea ice and surface waters were cells < 4 µm. They were less abundant in sea ice (418–3051 × 103 cells L− 1) than in surface waters (1393–5373 × 103 cells L− 1). In contrast, larger protists (≥ 4 µm) were more abundant in sea ice (59–821 × 103 cells L− 1) than in surface waters (22–256 × 103 cells L− 1). These results suggest a selective incorporation of larger cells into sea ice. The ≥ 4 µm protist assemblage was composed of a total number of 73 taxa, including 12 centric diatom species, 7 pennate diatoms, 11 dinoflagellates and 16 flagellates. The taxonomic composition in the early stage of ice formation (i.e., new ice) was very similar to that observed in surface waters and was composed of a mixed population of nanoflagellates (Prasinophyceae and Prymnesiophyceae), diatoms (mainly Chaetoceros species) and dinoflagellates. In older stages of sea ice (i.e., young ice and thin first-year ice), the taxonomic composition became markedly different from that of the surface waters. These older ice samples contained relatively fewer Prasinophyceae and more unidentified nanoflagellates than the younger ice. Diatom resting spores and dinoflagellate cysts were generally more abundant in sea ice than in surface waters. However, further studies are needed to determine the importance of this winter survival strategy in Arctic sea ice. This study clearly shows the selective incorporation of large cells (≥ 4 µm) in newly formed sea ice and the change in the taxonomic composition of protists between sea ice and surface waters as the fall season progresses. 相似文献