Evaluation of a Multi-species Test System for Assessing Acute and Chronic Toxicity of Sediments and Water to Aquatic Invertebrates: Effects of Pentachlorophenol on Daphnia magna and Chironomus prasinus (6 pp)

Background, Aims and Scope   Single-species toxicity tests are currently used as main tools for assessing effects in ecological risk assessments. Nevertheless, in higher-tier evaluations, alternative ecotoxicological methods can be required. Alternative methods should cover more realistic exposure conditions and/or additional species or endpoints. Water/sediment systems can be considered for covering additional exposure routes. A typical feature of water/sediment systems is the modification of exposure levels with time. The simultaneous exposure of different species within the same system can cover differences in sensitivity and relevance of exposure routes. The aim of this study was to develop a water/sediment test that could detect relevant effects on two selected species and explore the relevance of sediment and waterborne exposure routes. This alternative method may provide relevant information facilitating the design of microcosm and mesocosm studies.Methods   A multi-species water/sediment system was designed using two invertebrates: Chironomus prasinus a benthic detritivore invertebrate and Daphnia magna a pelagic filtering invertebrate was designed. Seven static water/sediments systems were built up: two controls and five treatments where sediments were spiked with NaPCP at nominal concentrations of 1.25, 2.5, 5, 10 and 20 mg/kg, respectively. Each system contained caged and free (unrestrained) Daphnia magna organisms to consider differences in the exposure route (through sediment and/or water column) and Chironomus prasinus organisms. Fate and partitioning of PCP within the water/sediment compartments were assessed. Acute (lethality) and chronic effects (reproduction) for Daphnia magna were monitored after 48 h and 16 days of exposure, respectively. Adult emergence and oviposition success of Chironomus prasinus were monitored at the end of test (16 days).Results and Discussion   Mortality and reproduction inhibition of Daphnia magna occurred at the two higher doses, corresponding to maximum measured PCP water concentrations of 1.95 and 0.746 mg/l, respectively. Chironomus prasinus was less sensitive to PCP than Daphnia magna. Concentrations inhibiting reproduction and provoking almost 100% adult mortality in D. magna only reduced slightly the emergence and reproduction of chironomids. The experimental design focussed on suitability of the system for assessing simultaneously assessing effects on D. magna and C. prasinus instead of calculations of toxicity endpoints for PCP. The results indicate that this experimental design can be useful to the field of sediment/aquatic toxicity testing, particularly through the comparison with single- species results. Assessment of relative contribution of two exposure routes for Daphnia magna and complementary chronic endpoints derived from two different species can be achieved. Another advantage is that differences in reproduction strategies of selected species (sexual vs. parthenogenetic) should permit one to detect mechanisms of action associated to with endocrine disrupters.Conclusion   The feasibility of a two-species test built-up in an artificial sediment/water system has been demonstrated. This experimental design represents a cost/effective test which can assess effects through water and sediment pathways and incorporates several relevant chronic endpoints in a single assay. Recommendation and Outlook   By building on the experience gained, improvements for further test designs are discussed. Test validation with a set of model chemicals will contribute to address the effectiveness of the test developed as comparing compared to single- species tests.     

5种杀虫剂在水-人工底泥系统中对大型溞的急性毒性及其比较

建立了包含＂水＂和＂底泥＂两相的水蚤毒性测试系统（水相为全人工培养液,＂底泥＂为OECD配方标准化人工土）,并通过该系统测得毒死蜱（chlorpyrifos）、氟虫腈（fipronil）、氰戊菊酯（fenvalerate）、氟氯氰菊酯（cyfluthrin）、联苯菊酯（bifenthrin）对大型溞（Daphnia magna）的急性毒性（48 h-LC50）分别为9.01、88.1、0.142、0.097 6、0.050 4μg.L-1。对比水相的急性毒性测定结果发现,在有底泥的条件下,所测得的联苯菊酯、氟氯氰菊酯、毒死蜱的大型溞毒性低于水相的测定结果,而氰戊菊酯、氟虫腈的毒性则比水相中的测定结果要高。研究结果反映出药剂和受试生物在＂水-底泥＂系统内相互作用的复杂性和难以预见性,从而在为相关农药生态安全评价提供科学依据的同时,为在更接近实际暴露状态下开展评价试验提供了一种简便有效的方法。     

四川盆地夏季鱼塘水温变化特征及预报

基于四川盆地南部富顺县水产养殖气象服务试验基地2017−2019年水温资料和同步气温资料,分析鱼塘夏季（6−8月）不同时间尺度上各层水温最高时段特征;以预报某日气温、前1日气温和水温作为预报因子,采用逐步回归分析建立夏季典型晴天状况下鱼塘各层平均水温、最高水温预报模型,并对模型预报效果进行检验。结果表明：夏季日内各层水温最高值出现在18：00−19：00,较气温滞后1～3h;水温≥32℃的时段主要集中在16：00−22：00,该时段内10、50和100cm深处水层逐时平均水温分别在32.9～33.1℃、32.6～32.7℃和32.1～32.3℃。夏季各层水温随气温呈波动上升趋势,水温最高值均出现在7月下旬;水温≥32℃的日数平均为23d,主要出现在7月下旬−8月中旬,该时段内10、50和100cm水层逐日平均水温分别在28.5～34.4℃、28.2～34.1℃和27.9～33.9℃。通过2017−2018年回带检验和2019年预报检验,模型预报平均绝对误差在0.3～0.8℃,平均相对误差在2.6%以内,预报效果较好,能较好地应用于夏季鱼塘水温预报。     

Stress Protein Responses in South African Freshwater Invertebrates Exposed to Detergent Surfactant Linear Alkylbenzene Sulfonate (LAS)

Stress responses can be measured at various levels of biological organization, from sub-organism through to ecosystem level. This study aimed to investigate stress protein induction as a sub-organism level stress response in two South African freshwater aquatic macroinvertebrates exposed to detergent linear alkylbenzene sulfonate (LAS). Shrimp Caridina nilotica and limpet Burnupia stenochorias were exposed to a range of LAS concentrations (0, 1, 1.8, 3.2, 6.5 and 12.7 mg/L and 0, 0.6, 1.2, 1.6 and 3.2 mg/L respectively) for 96 h. Surviving organisms were prepared for sodium dodecyl sulphate-polyacrylamide gel electrophoresis and Western blot analysis. In C. nilotica there appeared to be induction of a putative ≈ 70 kDa protein at 12.7 mg/L LAS, and induction of putative ≈45 and ≈40 kDa proteins at concentrations of 6.5 mg/L LAS and above. However, only an Hsp70 protein was detected with anti-Hsp72/Hsc73 at 12.7 mg/L LAS. No protein induction was observed in exposed B. stenochorias, however an Hsp40 protein was detected with anti-Hsp40 in exposed and unexposed limpets.     

白洋淀鱼类体内多氯联苯积累特征及其毒性评价

针对持久性有机污染物在水生生物体内易于积累的特性,利用气相色谱与质谱联用技术（GC-MS）,检测了白洋淀8种鱼类体内多氯联苯（PCBs）含量,并分析了同系物组成特征。根据白洋淀鱼类检测到同系物情况,计算毒性当量（TEQ）并进行评价。白洋淀8种鱼类体内PCBs平均含量范围是55.85~1 485.74 ng.g-1脂肪重,从高到低的顺序依次为黄颡〉黄鳝〉乌鳢〉泥鳅〉鲤鱼〉鳙鱼〉鲫鱼〉鲇鱼。在8种鱼类PCB同系物组成中,四氯联苯和五氯联苯是主要的同系物,其相对百分含量为52.0%~84.3%。这种组成模式反映了白洋淀地区有多氯联苯工业品的使用历史。8种鱼类体内PCBs的毒性当量（TEQ）范围是0.09~1 412.87 pg TEQ.g-1脂肪重,其大小顺序依次为鳙鱼〉鲫鱼〉鲇鱼〉黄颡〉黄鳝〉鲤鱼〉乌鳢〉泥鳅。结果表明,白洋淀淀区部分鱼类已经受到PCBs一定程度的污染,应引起重视。     

Bioaccumulation of 110mAg, 60Co, 137Cs and 54Mn by the Freshwater Crustacean Daphnia magna from Dietary sources (Scenedesmus obliquus and Cyclotella meneghiana)

The importance of food as radionuclide source for the crustaceanDaphnia magna was investigated using a planktonic food chain composed of young pre-adult daphnids and two algal species(Scenedesmus obliquus and Cyclotella meneghiana). Daphnids placed in a tank containing natural 0.45 μm filteredwater were fed on algae previously kept during 4 days in natural water contaminated by ^110mAg, ⁶⁰Co, ¹³⁷Cs and ⁵⁴Mn. After about one week of exposure, daphnids wereplaced in non-contaminated water on a diet of non-labelled algae,in order to monitor radionuclide release. The results suggest that the Trophic Transfer Factor (TTF) of radionuclides in daphnids was generally greater for the transfer via Scenedesmus than via Cyclotella> and that it could be linked to the intracellular fraction of accumulated radionuclidesand consequently to their biochemical behaviour. For theradionuclide transfer via Cyclotella meneghiana, the biological periods ranged, for the first compartment, from 7 to 30 min and for the second, from 10 h to 1.8 d. As regards thetransfer via the green algae Scenedesmus obliquus the biological half-lives were longer, since Tb₁ characterizing the first compartment, ranged from 11 min to 5.2 h, whereas Tb₂ ranged from 1.2 to 2.1 d. From an operational point of view, this paper underlines the importanceof considering the food contamination in the models of radionuclide transfer through trophic chains, in order to widentheir applications in different seasons or ecosystems.     

鱼池池水呼吸耗氧与藻类含量关系的研究

选定８个鱼池的水样在相同的外界条件下对池水呼吸耗氧与藻类含量进行了测定和分析,并以此设计出更精确更简便的实验方法：配比法。运用数理统计的方法对配比法得到的实验数据进行回归分析,得到了叶绿素ａ含量与耗氧速度、脱镁叶绿素含量与耗氧速度、叶绿素总量与耗氧速度三组函数关系式,并对其相关性进行了分析。     

鱼池池水呼吸耗氧与藻类含量关系的研究

选定８个鱼池的水样在相同的外界条件下对池水呼吸耗氧与藻类含量进行了测定和分析，并以此设计出更精确更简便的实验方法：配比法。运用数理统计的方法对配比法得到的实验数据进行回归分析，得到了叶绿素ａ含量与耗氧速度、脱镁叶绿素含量与耗氧速度、叶绿素总量与耗氧速度三组函数关系式，并对其相关性进行了分析。     

Uptake and Distribution of Lead (Pb) and Cadmium (Cd) in the Freshwater Crab,Potamonautes Perlatus (Crustacea) in the Eerste River,South Africa

This paper evaluates the effects of organic amendments and ironprecipitation on pore size distribution and mechanical resistancein sulphide mine tailings, as related to plant habitat requirements. Unaltered tailings, oxidised tailings collected from untreated, fertilized and sludge-amended plots in the field,and mixtures of unaltered tailings and organic amendments prepared in the laboratory, were analysed for pore size distribution. The organic amendments (sewage sludge, peat mossand paper mill sludge) were each applied at the rates of 0, 16 and 33% by volume. A difference in pore-size distribution between untreated and treated samples was shown in both field and laboratory samples. Both inorganic and organic amendments caused a decrease in pores holding water at soil water potentials–10 to –60 kPa, but increased the pores holding water at tensions below –60 kPa. This resulted in a decreased or unchanged content of plant available water (W_a) in all laboratory samples and in the fertilized field samples. Penetration studies in the field showed that additions of fertilizer, without any organic matter, had resulted in hardpans in the oxidised tailings that significantly increased themechanical resistance in the surface horizon. Thus, this studyindicates that the physical influence of the oxidation processestaking place in sulphide mine tailings can be magnified by additions of soil amendments. The aggregation of iron oxides and negatively charged particles such as organic substances orphosphate anions may cement the tailings, which can result inimpeded root growth.     

Inorganic Parameters as Water Quality Indicators in Acidic Groundwater in a Tropical Region – Brasilia-DF (Brazil)

In Brazilian Tropical Cerrado Region, reactions related to parental-material breakdown and oxisols genesis strongly affect the groundwater chemical characteristics. These reactions are responsible for the low water pH values, the soil charge balance, and the re-equilibrium of dissolved inorganic carbon species. Brasilia, the capital of Brazil, lies in the Distrito Federal, in the central part of the Brazilian Cerrado Region and has been experiencing an intense urban development during the last 15 years. Many town-house complexes have been built without proper water supply or wastewater disposal conditions. In this work, we discuss the adequacy of traditional ground waters geochemical classification models applied to the most exploited aquifers in DF. Forty groundwater samples were collected and pH, conductivity and total dissolved solids were determined in the field. Na, K, Ca, Mg, Fe, Al, Cu, Cd, Cr Mn e Zn were determined by Inductively Coupled Plasma Atomic Emission Spectrometry and Atomic Absorption Spectrophotometry. We identify inorganic indicators of human interference on the quality of these waters and also suggest a new mean of interpretation of dissolved inorganic elements based on statistic treatment of multivariate data. It is revealed a particular geochemical feature concerning to the alkali and the earth alkali metals concentrations, and a typical trace-element behaviour, closely related to the human activities and to the geological-bearing material characteristics. For all of the samples supposed to be altered by any kind of human activity, the physico-chemical parameters were lower than the standards established by the water quality legal system.     

Toxicity of Sb and Cu in Sewage Sludge to Terrestrial Plants (Lettuce,Oat, Radish), and of Sludge Elutriate to Aquatic Organisms (Daphnia and Lemna) and its Interaction

Antimony (Sb) and Copper (Cu) are two metals of major concern in sewage sludge. Antimony because its use in society is increasing and this might lead to increased Sb concentrations in sludge. Copper because its total volume in use in society is large and because of corrosion from water pipes it is most difficult to reduce the Cu concentrations in sludge. Fresh digested sewage sludge was spiked with Cu or Sb and the sludge was cultivated with oat (Avena sativa), lettuce (Lactuca sativa) or radish (Raphanus sativus). Elutriates from the cultivated sludge were tested for toxicity with Lemna minor (7-d growth) and Daphnia magna (48 h immobility). Before cultivation the elutriates were toxic to Lemna and Daphnia due to high concentrations of ammonia (NH₃) and nitrite (NO₂ ^-). Cultivation decreased the concentrations of both NH₃ and NO₂ ^-, thereby reducing the impact of these compounds in the toxicity tests. Cultivation also decreased the metal concentrations and pH. Daphnia magna was the most sensitive test organism in this study with a 48 h EC₅₀ of 1130 mg Cu kg^-1 dry wt and 5 mg Sb kg^-1 dry wt in elutriates from sludge cultivated with oat. In sludge cultivated with radish the 48 h EC₅₀ was 1700 mg Cu kg^-1 dry wt and 22 mg Sb kg^-1 dry wt. The effect of Cu could be predicted by pH and Cu concentrationin the elutriate, but the effect of Sb could not solely be explained by its concentration in the elutriate.     

Internal Mechanisms of Plant Adaptation to Aluminum Toxicity and Phosphorus Starvation in Three Tropical Forages

Many tropical forage grasses and legumes grow well in acid soils, adapting to excess aluminum (Al) and phosphorus (P) starvation stresses by using mechanisms that are still unclear. To determine these mechanisms, responses to Al toxicity and P starvation in three tropical forages were studied: two grasses, Brachiaria hybrid cv. ‘Mulato’ (B. ruziziensis clone 44-06 × B. brizantha cv. ‘Marandú’) and Andropogon gayanus, and one legume, Arachis pintoi. The tropical grasses tolerated high levels of Al toxicity and P starvation, with the Brachiaria hybrid maintaining very low levels of Al concentration in shoots. ²⁷Al Nuclear Magnetic Resonance spectroscopy (NMR) analysis revealed that, in the Brachiaria hybrid, Al makes complexes with some ligands such as organic-acid anions in the root symplast. The forages probably adapted to P starvation through high P-use efficiency. These experiments provide the first direct evidence we know of that organic acid anions within root tissue help detoxify Al in non-accumulator species such as the Brachiaria hybrid.     

Toxicity of Acidic Post-Mining Lake Water to Early Life Stages of Tench,Tinca Tinca (Cyprinidae)

Following abandonment of lignite mines, many acidic hardwaterlakes have formed in eastern Germany. Even after neutralisation,a risk of reacidification remains. In view of plans to use thepost-mining lakes for fisheries, acid tolerance of early life stages of tench, Tinca tinca, was determined using reconstituted post-mining lake water. Two experimental serieswere compared: A) incubation of the embryonic stages in Petri dishes and transfer of the larvae to aquaria, and B) incubationin aquaria throughout the experiment. All tench embryos exposedto pH 3.50–4.75 died prior to hatch. At pH 5.00, no (series B) or very few embryos (series A) hatched. The latter died shortly after hatching. At pH 5.50, the hatching percentage in series A did not differ significantly from that in the pH 7.40 control, whereas that in series B was reduced to halfof the control value. Transition to exogenous feeding was impaired in both series and mortality gradually increased.Consequently, overall survival at pH 5.50 only amounted to 4% in series A and 3% in series B. Reacidification to pH ≤ 5.50 would, thus, most probably pose a threat to earlylife stages of tench.     

Acute Toxicity of Gramoxone to Oreochromis niloticus (Trewavas) in Nigeria

The acute toxicity of paraquat (1,1-dimethyl-4,4-bipyridinium dichloride) to fingerlings of Oreochromis niloticus (Trewavas) was determined in 96 hr staticbioassays. During the assays opercular ventilation and tailfin movement rates of the fish were determined.Haemotological parameters of the blood and histopathology ofthe gills were observed.The 96 hr LC₅₀ of paraquat to fingerlings of O. niloticus was observed to be 11.84 mg L^-1.Histopathology of gills of the fish exposed to 12.00 mgL^-1, and 14.20 mg L^-1 showed a dose-dependentdisruption of the architecture of the lamellae, filamenthyperplasia and atrophy, leading to impairment in oxygenuptake. Other symptoms of toxicosis in exposed fish includeloss of equilibrium; agitated swimming; air gulping;haemorrhaging of the gills, pectoral and pelvic fins; periodof quiescence and finally, death.     

Carotenoids in three species of Corbicula Clams, Corbicula japonica, Corbicula sandai, and Corbicula sp. (Chinese Freshwater Corbicula Clam)

Carotenoids were investigated in three species of corbicula clams, Corbicula japonica, Corbicula sandai, and Corbicula sp. (Chinese freshwater corbicula clam). Forty-three carotenoids were isolated. Among them, 7,8-didehydro-beta-cryptoxanthin (12), peridininol 5,8-furanoxide (38), pyrrhoxanthin 5,8-furanoxide (40), and pyrrhoxanthinol 5,8-furanoxide (43) are newly reported as naturally occurring carotenoids. Their structures were characterized on the basis of UV-vis, FAB-MS including MS/MS experiments, and 1H NMR spectroscopic data. The total carotenoid contents in C. japonica, C. sandai, and Chinese freshwater corbicula clam were found to be 5.3, 2.6, and 0.3 mg/100 g in the edible part (wet weight), respectively. Peridinin (34) and its derivatives were found to be major carotenoids in C. japonica, which inhabits brackish water. On the other hand, lutein (13) was found to be the major carotenoid in C. sandai and Chinese corbicula clams, which inhabit freshwater. These patterns well reflected the carotenoids in their dietary algae. 7',8'-Didehydrodeepoxyneoxanthin (19), corbiculaxanthin (21), corbiculaxanthin 3'-acetate (22), and 6-epiheteroxanthin (24) were found in all three species of corbicula clams and have not previously been found in other shellfishes. They were assumed to be peculiar carotenoids in corbicula clams.     

Seasonal Variation of Lead in Fish Pond Waters of High Hunting Activity Area and Relation to Metals and Ions

Water, Air, &; Soil Pollution - Anthropogenic activities such as industry, agriculture, and daily life are related to metal pollution of the environment. Places known of the highest impact are...     

The Influence of Water Hardness, pH, and Suspended Solids on Nickel Toxicity to Larval Fathead Minnows (Pimephales promelas)

Nickel (Ni) is an ubiquitous, naturally occurring metalthat is associated with metal mining and other industrialactivities. Despite elevated Ni concentrations reportedfor many industrial receiving waters, Ni receives littleresearch attention addressing factors influencing itstoxicity to freshwater fish. This study examined theinfluence of water hardness, pH, and total suspended solids(TSS) in soft, reconstituted water on Ni toxicity to larvalfathead minnows (Pimephales promelas). Increasingwater hardness from 20 to 140 mg L^-1 (as CaCO₃) reduced acute Ni toxicity by 5-fold (96-h LC50s 0.45 and 2.27 mg Ni L^-1, respectively). Low pH had a slight protective effect against Ni toxicity relative to neutral pH conditions. At pH 5.5, the 96-h LC50 was 0.69 mg Ni L^-1, compared to 0.54 mg Ni L^-1 at pH 7.0. However,Ni toxicity was significantly reduced at pH 8.5 where the 96-h LC50 was 2.21 mg Ni L^-1. These results were explainedon the basis of Ni speciation. Total suspended solids also reduced Ni toxicity (expressed as 96-h LC50s) from 0.35 to 1.12 mg Ni L^-1 over a TSS range of 10 to 100 mg L^-1.This reduction of toxicity due to TSS is significant becausemine effluents often have a combination of elevated TSS andmetals. The ameliorative effect of TSS was not as significantas high hardness or pH probably because there is a TSS threshold, after which physical irritation to fish gills counteracts any protective effect conferred by TSS. This finding is relevant to choices made in design of mine effluenttreatment systems; i.e., there may be an optimum range ofTSS concentrations that protect aquatic biota againsteffects of metals that remain after treatment.     

Acute Toxicity of Seven Selected Pesticides (Alachlor, Atrazine, Dieldrin, Diuron, Pirimiphos-Methyl, Chlorpyrifos, Diazinon) to the Marine Fish (Turbot, Psetta maxima)

The present study evaluated the short-term toxicity of seven selected pesticides: four insecticides (chlorpyrifos, dieldrin, diazinon and pirimiphos-methyl) and three herbicides (diuron, alachlor and atrazine). With this aim, a standard toxicity test with the highly sensitive early life stages (ELS) of a marine fish was used. The turbot, Psetta maxima, is abundant in shallow estuarine and costal habitats and is currently the most commonly cultivated fish species in Galicia, NW Spain. According to the turbot ELS test results, chlorpyrifos was the most toxic pesticide tested for both embryos and larvae and was followed in order of decreasing toxicity by dieldrin, pirimiphos-methyl, diazinon, alachlor, atrazine and diuron. Larvae were more sensitive than embryos to the seven pesticides. The median lethal concentrations of the selected pesticides during a 48- and a 96-h exposure for turbot embryos and larvae were, respectively (in micrograms per litre): chlorpyrifos, 116.6 and 94.65; dieldrin, 146 and 97; pirimiphos-methyl, 560 and 452; diazinon, 1,837 and 1,230; alachlor, 2,177 and 2,233; diuron, 10,076 and 7,826; and atrazine, 11,873 and 9,957. According to their acute toxicity, the insecticides were more toxic than the herbicides. Furthermore, all insecticides and herbicides appear to be teratogenic to turbot ELS.     

杀虫剂对甘蓝蚜与七星瓢虫的毒力及选择性研究

试验研究杀虫剂对甘蓝蚜及其天敌七星瓢虫幼虫的毒力及选择性结果表明,15种供试杀虫剂中以吡虫啉对七星瓢虫幼虫和甘蓝蚜的选择性最高,其选择性毒力比值(瓢虫LD50/甘蓝蚜LD50)为174.29。5种有机磷类杀虫剂中以马拉硫磷的选择性最高,其次为敌敌畏,其选择性毒力比值分别为35.73和25.32;7种菊酯类杀虫剂中以氟氯氰菊酯和氯氰菊酯的选择性最高,其选择性毒力比值分别为55.16和30.00。故吡虫啉、氟氯氰菊酯和马拉硫磷等选择性较高的杀虫剂对甘蓝蚜相对毒力高,而对其天敌瓢虫相对安全,为防治菜田甘蓝蚜的理想品种。