Changes in phototactic behavior of Daphnia magna clone C1 242 in response to copper, cadmium and pentachlorophenol

In order to develop a sound biotechnique for monitoring water quality that builds on the previous experiments carried out in our laboratory, a specific D. magna clone C1242 was used to study the effects of pollutants on phototactic behavior, in all experiments, the animals showed a stable and repeatable phototactic index approximated 0.2 in the presence and 0.4 in the absence of fish kairomenes, which decreased significantly in response to pollutants. There existed no pollutant x fish kairomone interaction, indicating the changes in phototactic behavior of animals imposed by pollutants were independent of the presence of fish kairomones. The detection limits for changes in phototactic behavior of D. magna clone C1 242 are 0.04 mg/L for copper, 0.02 mg/L for cadmium, and 0.80 mg/L for PCP, respectively, quite lowerthan LC50(48 h). The changes in phototactic behavior in presence to pollutants occurred quickly(3 h) compared to the period over whole acute toxicity tests. Therefore, D. magna clone C1 242 could be potentially used to monitor water quality. Moreover, the phototactic behavior did not decrease further in the pollutant mixtures employed in our experiments compared to individual pollutants, except in the Cd-PCP Lre.atme~t.This fact suggests that the formation of water quality criteria must be based upon pollutant mixture tests.Keywords: Daphnia; phototactic behavior; copper; cadmium; pentachlorophenol; fish kairomenes     

The Problems of Fishermen in the Southern Aral Sea Region

The main objective of this paper is the presentation of water scarcity and water quality problems of fishery and fishermen in the southern Aral Sea region Kazakhstan. We tried in the past to inform interested people about our suggestions how to rehabilitate the situation, how to produce relatively enough fish for the functioning of local fish processing industry and to give people jobs, but we were unable so far to convince decision makers about innovations needed. It is essential therefore to reiterate some of the well-known problems of the region, called the Aral Sea crisis, but we concentrate mostly on the problems for the fishermen. While we do this, we understand, however, that the problem requires solution within the concept of a socioeconomic sustainable development for which we suggest the development of a decision support system based upon a computer simulation model providing optimal solutions.     

广西金钟山自然保护区鱼类资源考察报告

2004年11月14日至12月17日，在广西金钟山自然保护区内水域中共获淡水鱼类样品110余号，结合以往的调查资料。初步确定保护区淡水鱼类共有52种，分别隶属于4目13科1．45属．通过对保护区鱼类资源的实地考察，从生态区系的角度叙述了保护区野生鱼类资源的区系概况和分布特点，并对保护区鱼类资源的管理和合理利用提出了建议。     

鲁西北地区渍涝洼地人工鱼塘─台田的环境分析

鲁西北地区是黄淮海平原中低产田渍涝洼地的主要分布区之一。在鲁西北的禹城市，利用挖鱼塘、建台田的工程措施，综合改造利用这类洼地。工程实施后，通过水盐调控，改善了洼地的环境状况。监测结果表明：洼地台田土壤含盐量降低，土壤逐渐熟化。土壤有机质大量整治前后分别为０．５８２％（１９８６年）、０．９８９％（１９８９年）．土壤中的全氮、全磷也由整冶前的０．０２％、０．１４％上升到整治后的０．０６１％和０．１５８％。土壤盐分含量逐年降低，由０．５０～０．９２％下降到０．０６～Ｏ２９％。挖鱼塘建台田的生态工程措施，使浅层地下水地表化，解决了洼地积水蒸发等形成的盐渍化问题。综合环境效应显示，洼地原有的自然状况向良性转化，达到了初步治理的目的。     

Toxic effects of orimulsion on rainbow trout <Emphasis Type="Italic">oncorhynchus mykiss</Emphasis>

GOAL, SCOPE AND BACKGROUND: Orimulsion (stable emulsion of natural bitumen and water) is a new imported industrial fuel in Lithuania. No data on its toxicity to fish is freely available. The aim of this study was to investigate sensitivity of rainbow trout (Oncorhynchus mykiss) to acute and chronic toxicity of orimulsion and to estimate the Maximum Acceptable Toxicant Concentration (MATC) of orimulsion to fish. METHODS: Laboratory tests were conducted on rainbow trout in all stages of development (embryos, larvae, adults). Acute toxicity (96-hour duration) and long-term (28 or 60-day duration) tests evaluating the wide range spectrum of biological indices were performed under semi-static conditions. RESULTS AND DISCUSSION: Median lethal concentration (96-hour LC50) values and their 95% confidence intervals derived from the tests were: 0.1 (0.09-0.12) to embryos, 0.06 (0.05-0.07) to larvae and 2.22 (2.02-2.43) to adult fish, and 28-day LC50 to adult fish was found to be 0.26 (0.21-0.32) g/l of total orimulsion respectively. The acute toxicity of orimulsion to rainbow trout can be characterised by a narrow zone of toxic effect and a sharp boundary between lethal and sublethal concentrations. The lowest 'safe' or 'no-effect' concentration values of total orimulsion obtained in long-term tests were equal to 0.09 g/l to adult fish, 0.019 g/l to embryos, and 0.0017 g/l to larvae. Proposed value of 'application factor' for orimulsion was found to be equal to 0.03. Since orimulsion has the property to disperse in all water volume, its toxic effect on fish can be characterised by the combined effects of dispersion and water-soluble-fraction. CONCLUSIONS: Maximum Acceptable Toxicant Concentration (MATC) of 0.0017 g/l of total orimulsion to fish was derived from long-term tests based on the most sensitive parameter of rainbow trout larvae (relative mass increase at the end of the test). According to substance toxicity classification accepted for Lithuanian inland waters, orimulsion can be referred to substances of 'moderate' toxicity to fish. RECOMMENDATIONS AND OUTLOOK: For prediction and evaluation of toxic impact of orimulsion accident spills on fish, some recommendations should be given. Since orimulsion has the property to disperse in all water volume during short time periods, the amounts of both spilled orimulsion and polluted water should be ascertained. Once both parameters are known, the real concentration of orimulsion in the water body must be determined. Then this concentration must be compared with 'safe' concentration to fish. By use of 'application factor' 0.03, approximate MATC for other fish species can be estimated when only acute toxicity data (96-hour LC50 value) is available.     

Induced alkoxyresorufin-O-dealkylases in tilapias (Oreochromis niloticus) from Guandu river, Rio de Janeiro, Brazil

The activity of fish monooxygenases has been extensively used as a monitoring tool to detect contamination of water bodies by cytochrome P450-inducing agents. In this study we evaluated the activities of ethoxy- (EROD), methoxy- (MROD) and pentoxy- (PROD) resorufin-O-dealkylases in the liver of Nile tilapias (Oreochromis niloticus) collected at the Guandu river, at a reference clean site (Lake 1) and at two other sampling sites (Lakes 2 and 3) in Rio de Janeiro state, Brazil. Alkoxyresorufin-O-dealkylases were measured fluorimetrically in the hepatic S9 fraction. EROD (17.7-fold), MROD (14.2-fold) as well as PROD activities were considerably higher in tilapias from Guandu river. A moderate increase of EROD (5.0-fold) and MROD (5.4-fold) was also found in tilapias from Lake 3. These findings suggest that Guandu river watershed, the main source of urban drinking water supply in Rio de Janeiro, is polluted with CYP1A-inducing xenobiotics. Furthermore, we also found a good linear relationship between EROD and MROD, a finding that agrees with the hypothesis that the two reactions are catalysed by the same CYP1A isoform in O. niloticus.     

Cumulative and Residual Effects of Repeated Sewage Sludge Applications: Forage Productivity and Soil Quality Implications in South Florida,USA (9 pp)

Background, Aim and Scope The cow-calf (Bos taurus) industry in subtropical United States and other parts of the world depends almost totally on grazed pastures. Establishment of complete, uniform stand of bahiagrass (BG) in a short time period is important economically. Failure to obtain a good BG stand early means increased encroachment of weeds and the loss of not only the initial investment costs, but production and its cash value. Forage production often requires significant inputs of lime, N fertilizer, and less frequently of P and K fertilizers. Domestic sewage sludge or biosolids, composted urban plant debris, waste lime, phosphogypsum, and dredged materials are examples of materials that can be used for fertilizing and liming pastures. Perennial grass can be a good choice for repeated applications of sewage sludge. Although sewage sludge supply some essential plant nutrients and provide soil property-enhancing organic matter, land-application programs still generate some concerns because of possible health and environmental risks involved. The objectives of this study were to evaluate the cumulative and residual effects of repeated applications of sewage sludge on (i) bahiagrass (BG, Paspalum notatum Flügge) production over years with (1997–2000) and without (2001–2002) sewage sludge applications during a 5-yr period, and (ii) on nutrients status of soil that received annual application of sewage sludge from 1997 to 2000 compared with test values of soils in 2002 (with no sewage sludge application) in South Florida.Methods The field experiment was conducted at the University of Florida Agricultural Research and Education Center, Ona, FL (27o26’N, 82o55’W) on a Pomona fine sandy soil. With the exception of the control, BG plots received annual sewage sludge and chemical fertilizers applications to supply 90 or 180 kg total N ha–1 yr–1 from 1997 to 2000. Land application of sewage sludge and fertilizer ceased in 2001 season. In early April 1998, 1999, and 2000, plots were mowed to 5-cm stubble and treated with the respective N source amendments. The experimental design was three randomized complete blocks with nine N-source treatments: ammonium nitrate (AMN), slurry biosolids of pH 7 (SBS7), slurry biosolids of pH 11 (SBS11), lime-stabilized cake biosolids (CBS), each applied to supply 90 or 180 kg N ha–1, and a nonfertilized control (Control). Application rates of sewage sludge were calculated based on the concentration of total solids in materials as determined by the American Public Health Association SM 2540G method and N in solids. The actual amount of sewage sludge applications was based on the amount required to supply 90 and 180 kg N ha–1. Sewage sludge materials were weighed in buckets and uniformly applied to respective BG plots. Soil samples were collected in June 1997, June 1999, and in June 2002 from 27 treatment plots. In 1997 and 1999, soil samples were collected using a steel bucket type auger from the 0- to 20-, 20- to 40-, 40- to 60-, and 60- to 100-cm soil depths. Forage was harvested on 139, 203, 257, and 307 day of year (DOY) in 1998; 125, 202, 257, and 286 DOY in 1999; 179, 209, 270, and 301 DOY in 2000; and on 156 and 230 DOY in 2002 (no sewage sludge applications) to determine the residual effect of applied sewage sludge following repeated application. Forage yield and soils data were analyzed using analysis of variance (PROC ANOVA) procedures with year and treatment as the main plot and sub-plot, respectively. As a result of significant year effects on forage yield, data were reanalyzed annually (i.e., 1998, 1999, 2000, and 2002).Results and Discussion All sewage sludges used in this study were of class B in terms of USEPA’s pathogens and pollutant concentration limit. Pathogen and chemical composition of the class B sewage sludge that were used in the study were all in compliance with the USEPA guidelines. The liquid sludge (SBS11) had the lowest fecal coliform counts (0.2 x 106 CFU kg–1) while the cake sewage sludge (CBS) had the greatest coliform counts of 178 x 106 CFU kg–1. The fecal coliform counts for SBS7 was about 33 x 106 CFU kg–1. Average soil test values in June 2002 exhibited: i) decrease in TIN (NO3-N + NH4-N), TP, K, Ca, Mg, Mn, and Fe; and ii) slight increase in Zn and Cu when compared with the June 1997 soil test results. The overall decrease in soil test values in 2002 might be associated with nutrient cycling and plant consumption. Although the average BG forage yield in 2002 (2.3 ± 0.7 Mg ha–1) was slightly lower than in 2000 (3.5 ± 1.2 Mg ha–1), yield differences in 2002 between the control (1.2 + 0.2 Mg ha–1) and treated plots (2.3 ± 0.5 Mg ha–1 to 3.3 ± 0.6 Mg ha–1) were indicative of a positive residual effect of applied sewage sludge. This study has shown that excessive build up of plant nutrients may not occur in beef cattle pastures that repeatedly received sewage sludge while favoring long-term increased forage yield of BG. All sources of N (sewage sludge and AMN) gave better forage production than the unfertilized control during years with sewage sludge application (1997–2000) and also during years with no sewage sludge application (2001–2002). The favorable residual effects of applied sewage sludge in 2002 may have had received additional boost from the amount of rainfall in the area.Conclusions Repeated applications of sewage sludge indicate no harmful effects on soil quality and forage quality. Our results support our hypothesis that repeated land application of sewage sludge to supply 90 and 180 kg N ha–1 would not increase soil sorption for nutrients and trace metals. Results have indicated that the concentrations of soil TIN and TP declined by almost 50% in plots with different nitrogen sources from June 1997 to June 2002 suggesting that enrichment of nitrogen and phosphorus is insignificant. The concentrations of soil nitrogen and phosphorus in 2002 following repeated application of sewage sludge were far below the contamination risk in the environment. The residual effect of these sewage sludge over the long term can be especially significant in many areas of Florida where only 50% of the 1 million ha of BG pastures are given inorganic nitrogen yearly.Recommendation and Outlook Successive land application of sewage sludge for at least three years followed by no sewage sludge application for at least two years may well be a good practice economically because it will boost and/or maintain sustainable forage productivity and at the same time minimize probable accumulation of nutrients, especially trace metals. Consecutive applications of sewage sludge may result in build up of some trace metals in some other states with initial high metallic content, but in this study, no detrimental effects on soil chemical properties were detected. The possibilities for economically sound application strategies are encouraging, but more and additional research is required to find optimal timing and rates that minimizes negative impacts on soil quality in particular or the environment in general. For proper utilization of sewage sludge, knowledge of the sewage sludges’ composition, the crop receiving it, are absolutely crucial, so that satisfactory types and rates are applied in an environmentally safe manner. There is still much to be learned from this study and this investigation needs to continue to determine whether the agricultural and ecological objectives are satisfied over the longer term.     

Trace metal levels in freshwater fish, sediment and water

The trace metal concentrations in water, sediment and aquatic organisms, such as fish, could indicate the level and tendency of the pollution. This is important not only for the protection of the environment, but for evaluation of the quality of fish meat either captured from natural waters or cultured in fishponds. The total trace metal concentrations in samples of fish from different regions of Hungary and from different species have been determined by using an X-ray fluorescence technique (EDXRF). Water, sediment and fish samples from fishpond systems with different feeding and stocking has also been analyzed. In the case of zinc contents, differences have been traced between the cultured and wild common carp. In the case of common carp reared under different feeding conditions, differences were also observed in the zinc concentration. The retention of the trace metals in the fish has been studied by measuring the levels in sediment, water and feed. The different retention can be explained by the different availability of zinc in the applied feeds, which can be related to the presence of different metal species in the feeds.     

甲基异柳磷和三唑磷对几种淡水鱼的毒性比较

测定了有机磷杀虫剂甲基异柳磷和三唑磷对淡水鲳Ｃｏｌｏｓｓｏｍａ ｂｒａｃｈｙｐｏｍｕｍ尼罗罗非鱼Ｔｉｌａｐｉａ ｎｉｌｏｔｉｃａ和麦穗鱼Ｐｓｅｕｄｏｒａｓｂｏｒａ ｐａｒｖａ的急性毒性。其中甲基异柳磷对三种鱼的９６ｈＬＣ５０分别为１．３４、１．４６和０．１４ｍｇ／Ｌ,三唑磷为０．０６、０．０３５和０．００８ｍｇ／Ｌ,该测定结果表明,在常规用药条件下,甲基异柳磷对鱼类较为安全。     

Conservation Strategies for Endemic Fish Species Threatened by the Three Gorges Dam

Abstract:   The largest damming project to date, the Three Gorges Dam has been built along the Yangtze River (China), the most species-rich river in the Palearctic region. Among 162 species of fish inhabiting the main channel of the upper Yangtze, 44 are endemic and are therefore under serious threat of global extinction from the dam. Accordingly, it is urgently necessary to develop strategies to minimize the impacts of the drastic environmental changes associated with the dam. We sought to identify potential reserves for the endemic species among the 17 tributaries in the upper Yangtze, based on presence/absence data for the 44 endemic species. Potential reserves for the endemic species were identified by characterizing the distribution patterns of endemic species with an adaptive learning algorithm called a "self-organizing map" (SOM). Using this method, we also predicted occurrence probabilities of species in potential reserves based on the distribution patterns of communities. Considering both SOM model results and actual knowledge of the biology of the considered species, our results suggested that 24 species may survive in the tributaries, 14 have an uncertain future, and 6 have a high probability of becoming extinct after dam filling.