Transfer of Trace Elements in Water Area Ecology Systems of the Three Gorges Reservoir

The present study is to investigate the differences of Hg,Cr,Pb,Cd and Zn contents among water area ecology stystems of the three gorges Reservoir from water,dirt mud of the bottom and benthic fishes.The result show that content distribution of trace elements is:dirt mud of the bottom>benthic fishes>water;content distribution of trace elements in benthic fishes is:viscera>muscle>bone.The distribution factor of dirt mud of the bottom versus water,adsorption coefficient of benthic fishes versus dirt mud of the bottom and enrich coefficient of benthic fishes versus water is constant value in three Gorges Reservoir.Mercury is harm element to human in food chain.Besides,transform model of food chain in trace element are studied.     

Structure and energy demand of the benthic soft-bottom communities in the Java Sea and around the islands of Madura and Bali,Indonesia

In July 1984 benthic research was carried out in the Java Sea and around the islands of Madura and Bali.The aim was to describe the structure of the benthic communities in terms of numerical density (numbers of dominant macrofaunal groups and meiofauna per square metre) and biomass (g ashfree dry weight (AFDW) per square metre), and in relation to geographical position and main ambient factors, i.e. water depth, bottom temperature and sediment characteristics.In addition attempts were made to estimate the activity of these benthic ecosystems, and to show their relation to the pelagic.Box-core samples, collected along west-east axis in the Java Sea and in the Strait of Madura, showed relatively poor benthic communities. The average densities of macrofaunal organisms (> 1 mm) did not exceed 250 specimens·m⁻²; the total biomass was below 1 g AFDW·m⁻²; small polychaetes and crustaceans were the dominant groups.A number of larger organisms have developed very remarkable adaptations to the muddy environment. Meiofaunal organisms (nematodes being the dominant group) numbered 0.06·10⁶ to 0.46·10⁶ specimens·m⁻². In general there is a trend from west to east towards somewhat richer communities. The actual carbon demand of the benthic ecosystem in the area investigated is tentatively estimated at an average of 38 g C·m⁻²·y⁻¹, which amounts to about 40% of the primary production.Both the very soft fluid-mud bottoms in the central Java Sea and in Strait Madura, and the relatively low amount of energy available for growth, probably prevent the establishment of well developed benthic communities.     

The impact of fish predation on shallow soft bottoms in brackish waters (SW Finland); an experimental study

The impact of fish predation on shallow soft bottoms was studied by field and laboratory experiments. The field manipulations (caging experiments) were carried out in 2 shallow (1.5 m) bays in the northern Baltic Sea. An a priori hypothesis that fish do not structure macrozoobenthic communities in shallow soft-bottom areas was tested.Short-term aquarium experiments clearly showed that perch (Perca fluviatilis L.), roach (Rutilus rutilus L.) and ruffe (Acerina cernua (L.)) are all effective predators on benthic macroinvertebrates (Corophium volutator) Pallas and Nereis diversicolor O.F. Müller) under laboratory conditions. Thus fish can be considered a potential structuring force on benthic communities in shallow soft-bottom areas. Caging experiments of one to two month's duration (partial and total exclosure of fish and enclosure with perch) induced only minor changes in the benthic community. These results support the a priori hypothesis. One of our main conclusions is, however, that fish predation and other biotic interactions (competition, disturbance, etc.) together with abiotic factors play some role in the structuring processes. Multilevel testing is needed in studies on biotic interactions in the marine environment. Results from a specific environment should not automatically be applied to other kinds of habitats.     

The benthic biological submodel in the European regional seas ecosystem model

The submodel describing benthic biology including a bioturbation module as incorporated in the European Regional Seas Ecosystem Model (ERSEM) is discussed. It is linked to a nutrient dynamic model. The structure of the benthic model food web is presented. There are four macrobenthic functional groups, meiobenthos and aerobic and anaerobic bacteria. The modelling uses ‘standard organisms’ as basic building blocks. The choice of parameter values is discussed. The results demonstrate the dependence of the benthic system on the pelagic system. The importance of features such as predation within functional groups for stability of the system is investigated. Detritus input from the pelagic system and detritus recycling is most important in the benthic food web. The web of carbon and nutrient fluxes through the system is analysed. On the basis of the food web analysis, the trophic positions of the functional groups are calculated. Besides the benthic biology, the mathematical formulation of the bioturbation and diffusion enhancement is discussed. Macrobenthic presence and activity enhance diffusion in the sediment and contribute essentially to vertical transport of particulate matter. This is of great importance for the vertical distribution of detritus, and as a consequence, for microbial activity in the sediment layers.     

海河流域滦河水系夏季大型底栖无脊椎动物多样性调查

为了解海河流域滦河水系的生态完整性和底栖动物群落的恢复,2013年5—8月对滦河水系大型底栖无脊椎动物的群落结构特征进行了初步调查,共检测到大型底栖无脊椎动物90种,隶属于7纲11目65属。利用Shannon-Wiener多样性指数、Margalef丰富度指数、Pielou均匀度指数、Simpson多样性指数对滦河水系的水质进行了初步评价,在主成分分析和因子分析的基础上,对23个定量采样点的类型做了聚类分析。结果显示,水生昆虫23种,占26%;甲壳类2种,占2%;环节动物9种,占10%;软体动物10种,占11%;摇蚊幼虫46种,占51%。生物多样性指数表明滦河水系的整体水质为轻度污染,底栖动物的多样性与底质类型关系密切。     

On the population dynamics of dab,sole and flounder within bridgwater bay in the lower severn estuary,England

A ten year study of the population dynamics of the flatfish dab Limanda limanda, sole Solea solea and flounder Platichthys flesus was undertaken within Bridgwater bay in the Bristol Channel, England. Fish abundance was estimated from the rate of capture on power station intake filter screens at Hinkley Point Nuclear Power Station. The Bay was used as an 0-group nursery by all three species while flounder were alone in regularly using the area as adults. Using the coefficient of variation (CV) in annual catch as a measure of population stability these three flatfish were found to have some of the most stable populations within a fish community of 21 common species. When these species were classified according to their use of space as benthic, proximo-benthic or pelagic it was found that the benthic fish had the lowest CV values. It is argued that this stability is linked to their use of space. A notable feature was the differing seasonal occupancy of the Bay by the benthic fish which would act to reduce potential inter-specific competition. This suggests that spatial competition could only be intra-specific or against invertebrates. A search was made for biotic or physical factors correlated with year class abundance in the flatfish. The only significant correlation found was for sole, the abundance of which increased with increasing water temperature.     

The infauna and epifauna of the northern North Sea

This paper compares the infaunal and epifaunal assemblages from surveys encompassing 121 grab stations and 152 Agassiz trawl samples respectively, collected between 1980 and 1985. The area surveyed is delimited by the Scottish, Norwegian and Danish coasts lying between 56°15'N and 60°45'N. Samples for infauna and environmental parameters were collected by Smith-McIntyre grab and Craib corer.The epifaunal and infaunal assemblages were analysed separately by ordination techniques (DECORANA and TWINSPAN) to detect the major environmental gradients underlying the distribution and abundance of the fauna and to indicate which taxa were characteristic of different zones within the survey area.The major determinant of infaunal community composition was sediment granulometry, with depth being of secondary importance. For the epibenthos, depth was the major factor and the sediment composition seemed less significant. Assemblages identified by TWINSPAN were characterised by particular species, but these ‘community types’ were seen to grade into one another along continuous environmental gradients. These findings are discussed in relation to previous North Sea benthic classification schemes.     

湟水河上游大型底栖动物多样性及水体理化因子调查分析

为研究青藏高原农牧交错地带水生生物与环境指标的关系,于2015 年5 月（枯水季）和8 月（丰水季）,调查分析了湟水河上游47 个样点水体的理化指标和大型无脊椎底栖动物。水体物理指标现场采用多参数水质检测仪和FP311 杆式流速仪检测;采集水样带回实验室测定化学指标,总氮和总磷采用过硫酸钾氧化紫外分光光度法测定;NH4 -N含量采用纳氏试剂光度法测定。底栖动物采用索伯网和D形网采集。结果显示：支流各项理化指标数据均优于干流,尤其以浊度、细砂淤泥比例、NH4 -N、TN和TP 最为显著。底栖动物共鉴定出28 科57 属59 种,其中昆虫纲7 目54 种,占所有底栖动物种类的91.5%,个体数4444 头,占所有底栖动物数量的76.4%,甲壳纲、软体动物类、寡毛类等底栖动物个体数占底栖动物总量的23.6%。湟水河上游支流底栖动物平均分类单元数(6.76)基本与干流相当(8.04),对水质敏感的EPT平均分类单元数支流(3.36)也与干流相当(2.48),但干流底栖动物耐污染种类比例明显高于支流,而支流敏感种类比例明显高于干流。从底栖动物群落结构和水体理化指标来看,湟水河上游支流总体优 于干流,其差异源于干流受污染较重。     

Large-scale distribution patterns of the mussel Mytilus edulis in the Wadden Sea of Schleswig-Holstein: Do storms structure the ecosystem?

The distribution of mussel beds in the Wadden Sea of Schleswig-Holstein was mapped by aerial surveys from 1989 to 1991. The number of mussel beds decreased from 94 in 1989 to 49 in 1990, as a result of severe storms in early 1990. Thereafter only small changes were observed. The mussel beds that remained in 1990 were found only in the shelter of islands; all beds in exposed areas had disappeared between the surveys of 1989 and 1990, leaving large areas without mussel beds. Storms are thus identified as a major factor limiting the distribution of mussel beds to the sheltered parts of the Wadden Sea. Beds in the exposed parts of the Wadden Sea are highly dynamic, whereas beds in sheltered areas may persist over long times. A comparison with distribution patterns of older surveys (from 1937, 1968 and 1978) revealed great similarities with the results of recent investigations, indicating a constant distribution pattern over a long period.The results are discussed in relation to eutrophication and the structure of the benthic communities of the Wadden Sea. It is concluded that any eutrophication-induced increase of the mussel population would be restricted to the sheltered parts of the Wadden Sea. Storms will largely determine whether the communities of a given area have to compete with mussels, which are most important filter feeders of the ecosystem. As competition for food is a major factor structuring the benthic communities of the Wadden Sea, it is assumed that storms indirectly affect all other communities, giving deeper-burying, storm-tolerant species a competitive advantage in exposed areas where epibenthic mussels are excluded. The impact of mussel fisheries will be different for persisting and dynamic beds: fishing on persisting beds in sheltered areas may remove the crucial reserve which mussel-feeding birds such as eiders or oystercatchers need in times of low mussel populations.     

底栖硅藻生产性培养中的理论与实践

采用三种培养措施（Ⅰ.光照度2500-3000lx,一天一翻筐;Ⅱ.光照度2500-3000lx,3天一翻筐;Ⅲ.光照度1500-2000lx,3天一翻筐）进行底栖硅藻的生产性培养.结果表明:培养措施Ⅰ和Ⅲ获得的底栖硅藻种类组成(大型舟型藻、小型舟型藻、等片藻、菱形藻、直链藻、卵形藻的密度百分比分别为11.56±4.64,78.27±9.63,0.823±0.25,2.57±1.06,0.01±0.01,6.78±1.34和0.15±0.03,79.71±12.72,0.23±0.09,0.64±0.12,0.01±0.01,19.262±6.64)优于培养措施Ⅱ（大型舟型藻、小型舟型藻、等片藻、菱形藻、直链藻、卵形藻的密度百分比依次为23.56±10.47,38.47±9.85,22.51±9.86,10.24±2.86,5.22±1.68,0.007±0.002）,但培养措施Ⅲ所获得底栖硅藻总密度显著较低。说明采用较强的光照度（针对小型舟型藻类而言）结合每日翻筐的培养措施既能保证较优质的底栖硅藻种类组成,又提高了生长速度,迎合了水产经济动物苗种生产培养中对底栖硅藻的大量需求。     

Accumulation and the Harm of POPs to Organisms Lived in Lakes

The recent works about the accumulation and the harm of persist organic pollutions (POPs) to organisms lied in are widely distributed in lake ecosystem, transferred and biomagnified from prey to predator through pelagic and benthic food web, accumulated in high lipid organ, and increasing concentrations with the increasing of lipid content, age and body length. Until now, the present of POPs in lake ecosystem still has harmful effects to aquatic organism of lakes and can transfers to people through eating fishes from lakes and has some negative effects to human health.     

Copper,zinc and cadmium in benthic organisms from the Java Sea and estuarine and coastal areas around East Java

A study was made of the concentrations of copper, zinc and cadmium in benthic organisms, representing the phyla Mollusca, Arthropoda, Echinodermata and Pisces, from the riverine and estuarine areas of the rivers Brantas and Solo (East Java) and the adjacent coastal area. Moreover, an assessment was made of the contamination of the benthic biota with these elements in the Java Sea and Bali Sea.Benthic organisms show a species-specific uptake pattern for each element. Compared to the same type of animals from estuaries and coastal areas in temperate regions of western Europe, the concentrations of cadmium are considerably higher, while copper and zinc concentrations are somewhat lower.There is no general trend in concentration levels of the metals in specimens from rivers, estuaries, coastal zone and open sea. In some groups of organisms (e.g. shrimp, starfish) the concentrations of copper and zinc are highest in specimens from rivers and estuaries. In contrast, cadmium concentration levels in e.g. crab, shrimp and squid are lowest in riverine and estuarine areas.Significant differences in metal concentrations in these organisms were found between the dry monsoon period (July, August) and the beginning of the wet monsoon (November, December).No relationship existed between the metal concentration of the organisms and the silt fraction of the sediment (grain size < 63 μm) or the bulk sediment.     

The recovery of benthos following the impact of low oxygen content in the German Bight

The oxygen deficiency in the German Bight and in Danish waters 1981–1983 with ensuing benthos mortality was the reason for studying the development and re-establishment of the macrofauna in the following years. These years, from 1984–1987, exhibited more favourable oxygen conditions.The macrofauna of this region with its predominantly sandy substrate belongs to the Tellina fabula community. It is dominated by regular seasonal and ephemeral species such as Spio filicornis, Phoronis spec., Spiophanes bombyx and Lanice conchilega.In 1983, a year with exceptionally low oxygen content in bottom waters (< 1 mg O₂ dm⁻³), the macrofauna showed, in some parts of the investigated area, as reduction of approx. 30–50% in species numbers. Concurrently, the individual numbers of the remaining species were reduced. Beginning in 1984, a rapid recovery of benthic communities was observed. By 1986, biomass as well as species- and individual numbers rose to values similar to those determined by other authors in earlier surveys of the German Bight. In particular, juvenile Echinocardium cordatum and crustaceans have been observed since 1984 in larger numbers.     

春季生物膜对营养盐在水-沉积物界面扩散的影响

为了明确春季大沽河河口潮滩养殖功能的退化是否由食物（底栖藻类）匮乏所致,2009年5月在大沽河河口潮滩采集柱状沉积物样,利用氯化汞抑制沉积物表层生物膜的活性,研究生物膜对营养盐在水-沉积物界面迁移扩散的影响程度。结果表明,沉积物既可以是水体中营养盐的“源”也可以是其“汇”;在河道的近海侧,沉积物表面的生物膜会促进磷酸盐自沉积物向水体扩散;在其余区域,沉积物表面的生物膜会抑制营养盐自沉积物向水体扩散;在该河口潮滩,沉积物表层的生物膜均会抑制营养盐自沉积物向水体扩散。研究表明,春季大沽河河口潮滩贝类底播养殖功能的退化,并非食物短缺所致。     

镇江长江豚类省级自然保护区水域生态修复效果的监测与评价

自2006年以来,长江豚类极度濒危的生存状况得到广泛关注,在其自然保护区实施一系列生态修复工程,为镇江长江豚类省级自然保护区内的江豚提供良好的生存环境。于2015—2018年在和畅洲水域建设生态浮岛、人工鱼巢和放流底栖动物进行水域生态修复,对生态修复工程进行跟踪监测和效果评价。结果表明：生态浮岛的建设可提高区域内浮游植物和浮游动物的生物多样性和群落结构复杂程度;人工鱼巢对产黏性卵鱼类具有一定增殖效果,增殖种类主要为鲤、鲫、䱗和黄尾鲴;生态浮岛和人工鱼巢的建设对鱼类均有较好的聚集效果;底栖动物增殖放流显著增加了放流物种的丰度、生物量及保护区底栖动物群落生物量,增殖放流效果评价为中等。该自然保护区水域生态修复效果明显,为工程施工影响下水生生物保护区生态修复提供科学依据。     

The forage base of some reef fishes in the flores sea with notes on sampling and fishery

Data are given on the forage base of three reef fish species, Myripristis murdjan, Mulloidichthys auriflamma and Caesio coerulaureus obtained during the Indonesian-Dutch Snellius-II Expedition. Attention is given to relations with the environment and sampling techniques. Fishing with gill nets is the best sampling method, particularly for migratory species, Seasonal fishing for pelagic fishes is most important from an economic point of view. Additional exploitation of benthic and demersal resources is essential for subsistence.     

Nutrient dynamics in the North Sea: Fluxes and budgets in the water column derived from ERSEM

Nutrient dynamics for phosphate, nitrate, ammonium and silicate have been simulated with ERSEM, the European Regional Seas Ecosystem Model. From the model results budgets for the dissolved inorganic nutrients and the corresponding particulate fractions have been calculated. The annual cycles of the nutrients phosphate and silicate compare quite well with the observed ranges of variability. This does not hold for ammonium and nitrate. Biologically mediated transformations such as nutrient uptake and pelagic and benthic mineralization are the dominant processes in changing the nutrient concentrations with the horizontal advective contributions playing a minor role during the productive season.Vertical advection and vertical diffusion have a clear seasonal signal, with a maximum in February. The decay of the advective nutrient transport in summer is caused by the depletion of the upper layer of dissolved inorganic nutrients by algal uptake. The inflow of nutrients in the northwest is almost balanced by the outflow in the northeast, without causing large nutrient transports into the shallower areas from the north. However, from the coastal areas there is a nutrient flow towards the central North Sea, enhancing primary production in the central area.     

Long-term soft-bottom faunal changes in three shallow fjords,West Sweden

Three West Swedish fjords were investigated at the same 14 stations in 1976 and 1986, and 8 of these had been investigated in the 1920's. The stations are situated at 7 to 27 m water depths in protected areas without any significant local pollution input, but now with organically enriched sediments. Comparisons of benthic fauna between 1976 and 1986 showed the following significant reductions: in total mean abundance and biomass (excluding some large and rare species); in abundance and biomass of molluscs; in abundance of suspension feeders and carnivores. Similarity indices gave significant differences between 1976 and 1986, and between the 1920's and both 1976 and 1986. The greatest changes had occurred in the two fjords with the most restricted water circulation. Although these faunal changes may be attributed to several factors, recently increased periods of hypoxia in the bottom water, which could be a result of large-scale eutrophication, are suggested as the main impact on the benthos.