长江中游典型鱼塘植莲的环境与经济效益分析

长江中游湿地区域的池塘经过连续多年的化肥养鱼导致了大量的氮、磷沉积在鱼塘底泥中。分析了鱼塘植莲对养殖后沉积的氮、磷的重新利用及植莲的经济效益。实验于2004年在位于长江中游的武汉市涨渡湖渔场进行。根据收支平衡计算了实验池氮、磷的转移量,根据投入产出计算了实验池的经济收入。逐月分析了池塘中水质理化指标和底泥中总凯氏氮（TKN）和总磷（TP）的含量。方差分析表明：总凯氏氮、总磷在池塘底泥表层（0～5 cm）、中层（5～10 cm）和底层（10～50 cm）当中的含量都出现显著性降低(〖WTBX〗P〖WTBZ〗<005)。养鱼池塘通过植莲后,每公顷有1 50938±2211 kg氮和188995±282 kg磷被重新利用;鱼塘植莲产生的经济效益平均为每公顷52 031±1 579元。实验表明鱼塘植莲既能够有效地改善池塘养殖的生态条件,又能带来较高的经济收入,是长江流域湿地保护和综合利用的一种高效的农业生态模式。     

Mechanistic aspects of organophosphorothionate toxicity in fish and humans

Metabolic transformation plays a major role in the mechanism of toxicity of organophosphorous (OP) pesticides. The modulation of their toxicity by oxonases and monooxygenases, alone or in combination, has been shown in mammals and fish. Very limited information exists for the identification of the metabolic factors relevant in the human toxicology of such chemicals. In this paper, we develop a simple algorithm, based on in vitro data, for the identification of fish species more susceptible to diazinon (D). Similar algorithms are likely to be applicable to other organophosphothionate (OPT) pesticides. We also report on preliminary studies on the OPT substrate specificity of human liver cytochromes P450 (CYPs): such information may be useful to understand the role of sulphoxidation in OPT toxicity to humans and to identify individuals with increased susceptibility to OPT toxicity. Studies of the mechanism of OPT toxicity may provide useful tools for a more detailed characterisation of these chemicals, with reference to the risk for the human population and to the impact on the fish species present in specific environments.     

Using unexplained variation in the chemical composition of organisms for identification of xenobiotics in ecological studies

The contents of ten metals in the bone and muscle tissues were studied in three fish species from a water body located in the impact zone of a copper smelter. In the course of principal component analysis with “tissue” and “species” taken as instrumental variables (IVs), a high proportion of unexplained IV variance was revealed for xenobiotic elements, and the procedure of optimal scaling by the CATPCA method allowed their pattern to be estimated. It is proposed to use the unexplained variance of multidimensional data on the chemical composition of organisms for identifying the pattern of xenobiotics in environmental objects.     

浙江北部低洼田湿地农业种养结合模式的环境效应

浙江北部地区地势低洼,种粮易涝,严重制约当地农业的发展。2010年以来,作为湿地农业农作制度的创新,“水生作物 鱼类”种养结合模式在当地得到迅速发展。为了完善种养高效综合配套技术,在嘉兴市秀洲区3个农场开展了不同种养模式（藕 鱼和菱 鱼模式）的对比试验,对池塘水质、底质特征以及大气负氧离子浓度进行了分析。结果表明种养结合模式对池塘水质有一定改善作用。虽然养殖鱼类后水体有机污染有一定程度加重,但由于水生作物的吸收作用,使得水体氮磷含量明显降低。与菱 鱼模式相比,鱼塘种植莲藕后,对水质的改善效果更为明显。对底质的分析表明,鱼塘种植水生作物后,底泥中速效钾含量增加明显,尤其是在种植莲藕后。另外,由于施用化肥以及当年不收割引起的藕叶、茎杆等腐烂分解,使得藕 鱼模式池塘底泥中速效磷和总氮含量大幅增加,分别增加329.1% 和361.9%。对种养结合区域大气负氧离子浓度测定结果表明,种养结合开发利用有利于改善周边区域空气质量     

Interpretation of fish biomarker data for identification,classification, risk assessment and testing of endocrine disrupting chemicals

Chemical induced changes in fish biomarkers vitellogenin (VTG), secondary sex characteristics (SSC), and sex ratio indicate modes/mechanisms of action (MOAs) of EAS (estrogen, androgen and steroidogenesis) pathways. These biomarkers could be used for defining MOAs and the causal link between MOAs and adverse effects in fish for the identification of endocrine disrupting chemicals (EDCs). This paper compiled data sets of 150 chemicals for VTG, 57 chemicals for SSC and 38 chemicals for sex ratio in fathead minnow, medaka and zebrafish. It showed 1) changes in fish biomarkers can indicate the MOAs as anticipated; 2) in addition to EAS pathways, chemicals with non-EAS pathways induced changes in fish biomarkers; 3) responses of fish biomarkers did not always follow the anticipated patterns of EAS pathways. These responses may result from the interaction of chemical-induced multiple MOAs and confounding factors like fish diet, infection, culture conditions, general toxicity and stress response. The complex response of fish biomarkers to a chemical of interest requires EDC testing at multiple biological levels. Interpretation of fish biomarker data should be combined with relevant information at different biological levels, which is critical for defining chemical specific MOAs. The utility of fish biomarker data for identification, classification, PBT assessment, risk assessment, and testing of EDCs in the regulatory context was discussed. This paper emphasizes the importance of fish biomarker data in the regulatory context, a weight of evidence approach for the interpretation of fish biomarker data and the need for defining levels of evidence for the identification of EDCs.     

137Cs in freshwater fish in Finland since 1986--a statistical analysis with multivariate linear regression models

The accident at the Chernobyl nuclear power plant in 1986 significantly elevated the 137Cs levels of fish in Finnish lakes. About 6200 fish samples from 390 lakes comprising 20 species have been analysed for 137Cs since 1986. The sizes of the lakes varied from a few hectares to about 1000 km2. Activity concentrations of 137Cs in fish still varied widely in 2003, from 16 to 6400 Bq/kg fresh weight. This paper presents the results of statistical analyses with multivariate linear regression models carried out on the empirical data collected since 1986. The statistical analysis resulted in separate models for two time periods describing temporal changes of 137Cs in fish. The explanatory variables were fish species with various feeding habits, the size class of the lake, municipal division, drainage area, time since the deposition and deposition level of the municipality. The calculated values for 137Cs in fish did not differ statistically significantly from the observed values in the validation data. The explanatory variables explained 58% (the first time period) and 72% (the second time period) of the total variability of 137Cs in fish.     

Does climate change matter for freshwater aquaculture in Bangladesh?

Freshwater aquaculture plays an important role in the economy of Bangladesh, providing food, income, livelihoods and export earnings. However, freshwater aquaculture in the Mymensingh area of north-central Bangladesh has been accompanied by recent concerns over climate change. Field survey revealed that different climatic variables including flood, drought, rainfall variation and temperature fluctuation have had adverse effects on pond-fish culture. These climatic variables have detrimental effects on the ecosystem of ponds and thus affect survival, growth and production of fish. Changes in climatic variables have adverse effects on fish reproduction, grow-out operation, parasite infestation and disease occurrence. Considering vulnerability to the effects of climate change on pond-fish culture, we propose adaptation strategies that need to be introduced to cope with the challenges.     

鄱阳湖鱼类群落结构及其时空动态

为系统阐明鄱阳湖鱼类群落特征及其影响因素,以便为鄱阳湖的鱼类资源保护及可持续利用提供理论依据,2010年4~11月对鄱阳湖鱼类群落空间差异和季节动态进行了调查。结果表明,共调查到鱼类72种,隶属于7目14科46属。在群落结构上,江湖洄游型鱼类占鱼类种数的25.00%,河流型鱼类占鱼类种数的19.44%,湖泊定居型鱼类占鱼类种数的55.56%。在空间结构上,沿岸带共采集到鱼类49种,其中鲫(Carassius auratus)、鲤(Cyprinus carpio)、鲇(Silurus asotus)、黄颡鱼(Pelteobagrus fulvidraco)等10个种类在数量上占优势;敞水区共采集到鱼类68种,其中刀鲚(Coilia ectenes)、鲫(Carassius auratus)、贝氏(Hemiculter bleekeri)、似鳊(Pseudobrama simoni)等10个种类在数量上占优势;沿岸带鱼类密度和生物量在各样点间存在显著差异。在季节变化方面,敞水区物种数和生物量在月份间存在显著差异。鱼类群落组成与环境因子的CCA分析发现,影响鄱阳湖沿岸带鱼类群落的环境因子为水温、支流影响、离长江距离和透明度,而影响敞水区鱼类群落的环境因子为离长江距离和透明度。     

基于动态因子分析法的长江三角洲城市群城镇化质量测度研究

如何对多维数据进行降维处理在大数据时代显得愈加重要。传统的数据降维方法无法同时了解所有的动态变化趋势,因而具有一定的局限性。采取针对面板数据而设计的动态因子方法,以长江三角州城市群城镇化质量测度为例进行多维社会数据降维实验,结果发现该方法能够较为准确的识别多维数据中能够同时影响多个变量的“潜变量”,并可以刻画各个样本个体的“潜变量”随时间的变化趋势以及样本整体的变化趋势。结合案例研究结果可以发现,长江三角洲城市群同样存在人口城镇化和土地城镇化不协调的问题,需要加快新型城镇化建设,着重提升城镇化质量。     

Larval and Juvenile Fish Assemblage Structure of Inshore Habitats in the Middle Reaches of Li River,China: Spatial and Temporal Patterns in Relation to Abiotic Factors

To evaluate the effect of abiotic factors on larval and juvenile fish assemblage in shallow waters of middle reaches of Li River, Guilin, China. Samplings were taken monthly at 7 stations in the mainstream and 2 stations in 3 tributaries from May 2014 to April 2015. Synchronously, temperature, pH, turbidity, conductivity, dissolved oxygen rainfall and discharge were obtained. In all, 11.886 larval and juvenile fish from 18 species belonging to 8 families, 16 genera was captured. Principal Component Analysis (PCA) showed obvious significant difference between the environmental variables across sampling areas and months. The results of Canonical Correspondence Analysis (CCA) indicated that water temperature, turbidity, discharge and rainfall were dominant factors on larval and juvenile fish assemblage.     

Assays with Daphnia magna and Danio rerio as alert systems in aquatic toxicology

For the evaluation and monitoring of the water quality, a series of methodologies, which have as basis an ample variety of bioindicators, may be applied. The aim of this research was to evaluate the use of ecotoxicity assays with Daphnia magna and Danio rerio as alert systems in water contaminated with toxic substances. Using two toxicity databases, the sensibility of those aquatic organisms to a wide variety of chemical products and elements and to some chemical categories was investigated. The relation between the reference dose for human oral chronic exposure (RfD) of all chemical products and the acute toxicity values for both bioindicators was also studied. Acute toxicity tests with D. magna respond to a larger variety of chemicals with a higher sensitivity than those with D. rerio. Although mammals, crustaceans and fish have different routes of exposure, target organs and toxic mechanisms, acute toxicity essays with fish and Daphnia may be used as an initial screening before mammal models are used.     

Uptake, retention and organ/tissue distribution of 137Cs by Japanese catfish (Silurus asotus Linnaeus)

The work describes the uptake, retention/biological elimination and organ/tissue distribution of 137Cs by freshwater Japanese catfish (Silurus asotus Linnaeus) under laboratory conditions. The fish were divided into three groups based on their size and age and reared in 137Cs-spiked water. The concentration of 137Cs in the whole body of the live fish was measured at regular intervals up to 60 days. A significant accumulation of 137Cs was found, but a steady state condition was not achieved by the end of the experiment. The bioaccumulation factors at steady state and the required time to reach steady state were estimated to be 1.55 and 255 days, 1.76 and 180 days and 1.99 and 160 days for large, medium and small size fish, respectively. To determine the effective half-life of 137Cs, the fish were transferred and reared in the non-contaminated host water. The concentration of the remaining 137Cs in the whole body of the live fish was measured up to 66 days. The average effective half-life of 137Cs in the fish species was found to be approximately 142 days for fish of all sizes. The distribution of 137Cs in different organs/tissues of the fish was determined. Accumulation of 137Cs in muscle/flesh of the fish was found to be approximately 75% of whole body accumulation. The uptake rate and the retention capability of juvenile fish were found to be higher and therefore, these were more susceptible to 137Cs than adult and old fish, and could be an important source of 137Cs in the human food chain.     

Levels of PCDD/PCDFs and PCBs in edible marine species and human intake: a literature review

Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) are lipophilic organic compounds whose origin comes from many different sources. PCDD/Fs and PCBs are ubiquitous and persistent environmental pollutants with a well known potential toxicity, which were included at the 1998 UN-EC POP protocol. Although human exposure to PCDD/Fs and PCBs can occur by various routes, food is the primary source. A number of studies have shown that the major food sources of these organic pollutants are fat-containing animal products, including fish and other seafood. Because of the frequent health recommendations concerning fish consumption, to determine the contribution to the dietary intake of chemical contaminants such as PCDD/Fs and PCBs through fish and other seafood consumption is an issue of special interest. This paper reviews the state of the science regarding recent literature on PCDD/F and PCB levels in marine species and human intake through fish and seafood consumption. The concentrations of these pollutants depend basically on the environment in which the respective species are caught. It is concluded that some groups of population frequently consuming high quantities of certain species could be significantly increasing health risks due to PCDD/F and PCB exposure.     

Uptake and elimination of radiocaesium in fish and the "size effect."

A number of hypotheses have previously been developed concerning the rates of uptake and elimination of radiocaesium (137Cs) in fish. These include the influence of potassium and other water chemical parameters on both uptake and elimination, and the effect of fish size on accumulation. In order to test these hypotheses, we have assembled a data set comprising more than 1,000 measurements of radiocaesium (137Cs) in predatory fish (perch, pike and brown trout) in nine European lakes during the years after Chernobyl. These data have been analysed using simple models for uptake and excretion of 137Cs in fish, showing that: 1. Fish-water concentration factors (CF) were inversely proportional to potassium [K+] concentration of the different lakes, in agreement with previous studies. 2. The uptake rate of 137Cs in fish was negatively correlated with lake [K+], but excretion rate was independent of [K+]. 3. Lower than expected CF values were found in one lake, Iso Valkj?rvi, Finland. This is attributed to inhibition of the K+ (and therefore 137Cs) high affinity transport system in aquatic plants and fish by low pH and/or low Ca2+. 4. The inclusion of fish weight as a parameter in our dynamic model significantly improves the ability of the model to fit the observed measurements of 137Cs. 5. The model developed from the above hypotheses was able to fit the data from nine different lakes to within approximately a factor of 3 of the observed values.     

Development of an environment-friendly feeding management for pond-reared fish species in the Segara Anakan Lagoon, Java, Indonesia

Inefficient feeding practices for producing fish in captivity create environmental problems. Therefore, the feed input should be reduced to a level that does not result in negative impacts of fish production. Reducing feed input can be done by periodic feed deprivation which does not necessarily decrease the fish production. This study was designed to investigate the effect of repeated unfed–fed cycles on the growth and feed utilization of the orange-spotted grouper Epinephelus coioides raised in floating net cages in estuarine ponds. The trial was conducted in the north east of Segara Anakan, Java, Indonesia. The fish were purchased from local fishermen and mean fish body weight was 53.2 g. After acclimation in the cages for 2 weeks, 500 fish were randomly assigned to four feeding groups. The groups included: fish fed daily as a control (C); fish not fed every Monday and Thursday and fed on Tuesday and Wednesday, then on Friday, Saturday and Sunday (T1); fish unfed every Sunday, Monday and Thursday and fed on Tuesday and Wednesday, then on Friday and Saturday (T2). The experiment ran for 10 weeks. The results showed that reducing feed input by repeating unfed–fed cycles induced compensatory growth of the fish. Application of this feeding regime provides flexibility in feeding management and may reduce organic discharge into the environment. Reduction of organic pollution should help the sustainable use and conservation of the Segara Anakan ecosystem.     

The unpredictable effects of mixtures of androgenic and estrogenic chemicals on fish early life

Estuarine shallow areas and coastal lagoons are known to receive and concentrate multiple inputs, either from land, rivers or coastal areas, being intensively impacted by chemical contamination, namely endocrine disrupting chemicals (EDCs). Despite the ubiquitous coexistence of several classes of EDCs in most of these aquatic ecosystems, there is still limited information regarding their combined effects. Furthermore, given the immediate implications for population dynamics, the available laboratory studies almost invariably focus on very specific life history stages, such as embryonic development or reproduction, thus creating a gap on our knowledge of what happens in between. During this 'intermediate phase', the newborn larvae and juveniles face numerous challenges whose outcome may impair reproduction or even survival. The black-striped pipefish, Syngnathus abaster, member of the Syngnathidae family (comprising pipefish, seahorses and seadragons), usually breeds in coastal areas such as estuaries, where its newborns are immediately exposed to EDCs. Given the ongoing decline of pipefish populations, together with the observed shrinkage and fragmentation of seagrass meadows, known to be impacted by EDCs, a first reasonable question to address is if pipefish newborns respond to environmentally relevant concentrations of ubiquitous EDCs, either single or in combination. Hence, a seven days exposure experiment to the estrogenic chemical ethinylestradiol (EE(2)) and the androgenic chemical tributyltin (TBT), single and in binary mixtures, was conducted. Selected behavioural (e.g. predator avoidance) and developmental variables (e.g. growth) were monitored in pipefish juveniles after EDCs insult. The obtained results indicate that EE(2), TBT, or their combined exposure, do impact pipefish early life. However, the pattern of results emerging from the measured variables clearly indicates that mixtures significantly modulate newborn responses in distinct ways when compared to individual chemical's exposure. These findings further demonstrate the importance of addressing the issue of chemical mixtures of pollutants acting through dissimilar mode of action. Independently of all the observed response variations, an ultimate conclusion seems certain: EE(2) and TBT, single or in combination, induce disruption patterns able to imbalance pipefish survival. Since these (as well as other) contaminants are present in estuarine areas, profound implications in population structure could be expected, ranging from a decrease in recruitment to a disruption of sexual selection. Inexorably, these stressors simultaneously operate in already declining populations.     

Fish ingestion and congener specific polychlorinated biphenyl and p,p'-dichlorodiphenyldichloroethylene serum concentrations in a great lakes cohort of pregnant African American women

A cohort of low income, city dwelling, pregnant African American Women (delivered from 1994–1999) was assembled to identify factors related to organochlorine exposure through consumption of Great Lakes resources. The cohort is known as the Great Lakes Cohort of Pregnant African American Women (GLCPAAW). Pregnant women from metropolitan Chicago, IL area clinics were administered a questionnaire on diet, demographics, and health history. Weight, height, and serum lipids were measured at delivery along with serum organochlorines such as PCBs and DDE. Congener specific concentrations of PCBs and p,p'-DDE found in the maternal serum are reported. Dominant PCB congeners found in the serum of the pregnant women at delivery included PCB 101, 118, 138, 153, and 180. The high prevalence and magnitude of PCB 101 (greater than the limit of detection in > 80% of the women in the cohort) are unique characteristics of this cohort.Great Lakes fish has been identified as a source of exposure to organochlorines in several studies. Spearman correlations and robust regression models were utilized to identify the impact of Great Lakes fish ingestion on cohort serum organochlorine concentrations. Several potential confounders of the relationship between serum organochlorines and Great Lakes fish consumption were identified. Covariates related to organochlorines in correlations as well as regression models included age, body surface area, fish ingestion, lipids, parity, race and smoking. Lower chlorinated PCB congeners do not follow the same trends as the higher chlorinated congeners and DDE. The higher chlorinated PCB congeners (PCB 138, 153, and 180) and DDE were correlated with age while the lower chlorinated congeners were not. PCB 153 and 180 regression models included age as a significant covariate. None of the higher chlorinated congeners correlated to race, while both lower chlorinated congeners were correlated to race. Race was also significant in both lower chlorinated congeners' regression models. PCB 101, a lower chlorinated congener seldom found in human serum, is readily found in the cohort. Airborne PCB exposure as well as diminished metabolism of PCB 101 in African Americans may explain the increased presence of PCB 101 and it's correlation with race.High end sport fish consumers (≥ 1meal per week) carried elevated levels of DDE and higher chlorinated PCB congeners (138, 153, and 180) compared to non-sport fish eaters. Unexpectedly, DDE was correlated more consistently with fish ingestion and age (a marker of bioaccumulation) in comparison to PCBs. Small correlations were found between serum PCBs and fish ingestion (Spearman correlation = 0.19 for total PCBs and fish meals per year). Additionally, Serum PCBs in low end Great Lakes sport fish consumers were not higher than non-consumers. These findings suggest the women of the cohort are being exposed to PCBs through other routes in addition to Great lakes sport fish. One major route of exposure may be Chicago air. The observed trends amongst individual PCB congeners has important ramifications because lower chlorinated congeners or their metabolites may be mediators of toxicity. Organochlorine exposure through Great Lakes fish ingestion was clearly identified in high end fish consumers while associations with race, metabolism, and possible airborne exposures pose new questions.     

An in vitro/in vivo screening assay as a sensitive tool to assess endocrine disruptive activity in surface water

Adult male fathead minnow were exposed for 14 or 28-days under flow-through conditions to undiluted filtered water samples from the rivers Meuse and Rhine in the Netherlands. The experiment included two vessels per treatment each containing 10 fish and samples of five fish were taken after 14 and 28 days. Additional groups were exposed to 17alpha-ethinylestradiol (EE2) as a reference and untreated drinking water as a negative control. Major endpoints examined included induction of vitellogenin (VTG) synthesis, VTG mRNA activity, hepato- and gonadosomatic indices (HSI and GSI) and gonadal histology. No significant difference was recorded in body weight or mean GSI values between the various treatments. Only exposure to Meuse water resulted in significantly higher HSI means after 14 days. Histological examination showed no apparent effects on gonadal tissue except for eosinophilic blood plasma in fish exposed to Meuse water or EE2. After 14 and 28 days, elevated VTG and VTG mRNA levels were measured in most livers of the fish exposed to Meuse water, but not in the fish exposed to Rhine water. This was confirmed by measuring estrogenic responses in the in vitro ER CALUX assay. Induction of VTG synthesis proved to be the most sensitive endpoint in the Non Spawning Male Fish Assay for in vivo detection of bio-available estrogenic activity supplementary to a sensitive in vitro assay. The other endpoints examined varied too much and required a higher number of fish or replicates to achieve sufficient power for statistical testing making them less animal friendly.     

TCDD distribution in the Spring River,Southwestern Missouri

The waste management practices of a now defunct chemical company created several disposal sites containing 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) contaminated materials. A sampling survey of the Spring River, which drains the disposal sites, was conducted to determine if TCDD contamination of this river had occurred. TCDD was found in fish at concentrations of 0.8 to 55 ng/kg (whole fish) and 1.4 to 18. ng/kg (fillet). In addition, TCDD was present in the fish at least as far as 69 mi (111 km) downstream of the disposal sites. The detection limits were generally not sufficient to determine the sediment TCDD concentration in the river. TCDD was only found in the sediments immediately downstream of the former manufacturing facility, at 12 ng/kg.     

基于葛洲坝1号船闸模型的水流诱鱼试验研究

以鲢鱼(Hypophthalmichthys molitrix)为研究对象,在自制的葛洲坝船闸模型中,研究水流诱导鱼类进入船闸的技术。诱鱼效果采用鱼平均聚集率(P)、诱集效率指数(I)、通过闸门频次(f)和上下游停留时间比(Tr)作为评价指标。研究结果表明:适当范围的水流流速对诱导鱼类进入船闸有一定的诱集作用。当闸门断面平均流速为0.45 m/s时,诱集效率最高,此时鱼类在船闸两侧区域平均聚集率和诱集效率指数最大,通过闸门频次最高;当水流流速为0 m/s(对照组)时,鱼类的活动规律不明显;当水流速度大于0 m/s且小于0.45 m/s时,鱼群聚集中心主要集中闸门内高流速区域;当流速超过0.45m/s后,逐渐增大时,鱼类进入船闸的频率呈下降趋势,鱼群聚集中心主要集中在闸门下游侧流速较稳定的区域;当流速超过0.75 m/s后,鱼类的顶流行为逐渐减弱,不再呈现向闸门聚集的趋势,出现逃逸行为。通过本研究,为鱼类行为学的研究提供基础数据,同时为中低水头水利枢纽船闸与鱼道结合的可行性研究提供参考依据。