Wastewater management for hazardous chemicals ‐ disposal of ammonium perchlorate wastes from propellant production for space vehicles

An attempt to depict the wastewater treatment system for the production of ammonium perchlorate, a component of solid propellant used in space vehicles, has been made. The waste‐water management system uses solar ponds and seawater dilution for the retention and disposal of the undesirable constituents of the wastewater. The details of the wastewater generation and its treatment are highlighted in this paper.     

Influence of temperature and pH on the effects of zinc and copper on proteolytic activities of the intestinal mucosa of planktivorous and benthophagous fishes and their potential preys

Influences of temperature (0 and 20°C) and pH (3.0, 5.0, and 7.4) on the effect of zinc (Zn) and copper (Cu) on proteolytic activities of intestinal mucosa in planktivorous (blue bream, bleak), bentophagous (bream, roach) fishes and their potential preys (pond snail Limnaea stagnalis, planorbid Planorbarius purpura, dreissena Dreissena polymorpha, midge larvae Chironomus sp., water flea Daphnia longispina and total zooplankton) are revealed in this article. Cu decreases the caseinolytic and hemoglobinolytic activities in both fish and their preys more than Zn at temperature 20°C and pH 7.4. Low temperature intensifies the negative effect of the metals on the protease activity in fish (in the case of Zn 5–10 times, in the case of Cu 5–30 times). In fish prey species, the negative effect of the metals on the proteinase activity may be more significant. The influence of pH on Zn and Cu effects is less pronounced than that of low temperature. Maximum reduction of enzyme activities is observed for the combined action of low temperature and pH as well as of the studied metals.     

Atypical plant–herbivore association of algal food and a kleptoplastic sea slug (Elysia clarki) revealed by DNA barcoding and field surveys

The identity of food sources and feeding preferences of specialist herbivores have been commonly inferred from spatial associations between consumer and food items. However, such basic information for well-known marine herbivores, sacoglossans (sea slugs), and their algal diets remains disappointingly lacking, especially from field studies. The sacoglossan, Elysia clarki (Pierce et al. in Molluscan Res 26:23–38, 2006), is kleptoplastic and sequesters chloroplasts from algal food to photosynthesize, so DNA identification of sequestered chloroplasts was employed to verify the algal species fed upon by the slug across its geographic range. The molecular information on the algae consumed by E. clarki was combined with field surveys of slugs and algae in slug habitats in the Florida Keys in July and August of 2008 in order to evaluate whether the diet of this herbivore could be predicted based on its spatial association with algae in the field. A considerable mismatch between food availability and kleptoplast identity was recorded. E. clarki commonly occupied areas devoid of potential food and often contained symbiotic plastids from algal species different from those most frequently found in the surveyed habitats. In three of the four study sites, algal species present were poor predictors of slug diet. These findings suggest that the photosynthetic capability of E. clarki may release the slug from the constraint of requiring proximity to its food sources and may allow for the potential lack of spatial coupling between this herbivore and its algal food. This combination of field surveys and DNA barcoding provided critical and previously unavailable information on herbivore feeding in this marine system.     

Integrated environmental assessment of freshwater sediments: a chemical and ecotoxicological approach at the Alqueva reservoir

In order to study the pollution of an aquatic ecosystem, it is necessary to analyze not only the levels of chemical pollutants in water, but also those accumulated in the sediment matrix, as well as to assess its ecotoxicological status. The Alqueva reservoir, the largest artificial lake in Europe, was chosen as case study as it constitutes the most important water supply source in southern Portugal. It is located in the Guadiana River Basin, in a semi-arid region with high levels of water scarcity and where agriculture is one of the main activities. The evaluation of sediments comprised: (1) physical and chemical analysis (grain size, pH, organic matter, nitrogen, phosphorus); (2) potentially toxic trace elements (Cu, As, Pb, Cr, Cd, Zn and Ni); and (3) ecotoxicological evaluation with Vibrio fischeri, Thamnocephalus platyurus, Daphnia magna, and Heterocypris incongruens. Total trace element concentrations indicated that As, Cd, and Pb surpassed the Canadian levels for the protection of aquatic life, in most of Alqueva’s sites. The results of the toxicity assessment showed that some locations induced acute and chronic toxicity in the species used. Further, the H. incongruens was the most sensitive species as far as the contamination found in the sediment is concerned, followed by the bacteria V. fischeri. This integrative approach, together with the water column quality assessment, allowed a comprehensive evaluation of the environmental quality of this strongly modified water body and will allow the implementation of remediation strategies to obtain a good ecological potential as proposed in the Water Framework Directive.     

多环芳烃（萘）对火腿许水蚤（Schmackeria poplesia）急性和慢性毒性效应的研究(A Study on the Acute and Chronic Effects of NAPH on Schmackeria poplesia)

为初步探讨内分泌干扰物多环芳烃对海洋桡足类生物所产生的生物效应,研究了萘对火腿许水蚤(Schmackeria poplesia)的急性毒性作用及其在1.6μg·L-1、16μg·L-1、160μg·L-1浓度下对火腿许水蚤变态率、存活率、繁殖力、性别比和体长的影响.结果显示,萘对火腿许水蚤48hLC50和96hLC50分别为4589.34μg·L-1和1559.55μg·L-1;各浓度萘均引起火腿许水蚤幼体的变态率显著降低;160μg·L-1萘条件下,火腿许水蚤的存活率、产卵率和抱卵雌体比率均显著降低;各浓度的萘对火腿许水蚤的性别比和体长均未造成显著影响.研究表明,在目前的环境浓度下,多环芳烃(萘)对海洋桡足类生物可能造成的生态风险较低.     

Incidence of kyphosis deformities in natural population of <Emphasis Type="Italic">Atherina lagunae</Emphasis> (Trabelsi et al. 2002) from the Tunis North Lake,Tunisia

Vertebral abnormalities are common among fish and this constitutes a problem of quality and cost-efficiency in aquaculture and in fisheries. Information is presented on the occurrence of spinal deformities in natural population of Atherina lagunae (Teleostei, Atherinidae) in Tunis North Lake (Tunisia). This species is euryhaline and lives in most Mediterranean lagoons. A total of 2,175 fish were caught, in monthly samples, from October 2004 to August 2005. Deformed fishes were counted, photographed and radiographed. According to X-ray radiographies, kyphosis were the most common externally visible vertebral deformities. This abnormality was observed in 212 atherines (140 males and 72 females). The spinal deformity levels varied between 5.34% in December 2004 and 15.85% in June 2005, and averaged 9.75%. The rate of deformed fish varied considerably according to sex and size. The possible reasons of this deformity are also discussed.     

Coordinated mechanics of feeding,swimming, and eye movements in <Emphasis Type="Italic">Tautoga onitis</Emphasis>, and implications for the evolution of trophic strategies in fishes

Fish feeding behavior results from successful coordination of the fins, jaws, and sensory systems, and the organization of this behavior may affect the fish’s foraging abilities and trophic ecology. Using quantitative kinematic methods, movements of the jaws, fins and eyes of Tautoga onitis (Teleostei: Labridae) were analyzed during feeding events. Tautog feeding events consisted of three phases: approach, strike, and recovery, each defined by a combination of kinematic events. The approach was characterized by changes in fin movements and in body position, with the eyes directed forward at the food item. The strike began with the onset of jaw opening and protrusion, then cranial elevation, with the eyes no longer looking at the food item. The end of the strike and the beginning of the recovery involved a braking maneuver with the pectoral fins; the fish turns and swims away from the original food location item after prey capture. The coordination performance variables of tautog were quantitatively compared to published data from closely related cheiline wrasses and parrotfishes, which represent different feeding ecologies within a monophyletic assemblage. Fishes feeding on molluscs and benthic invertebrates (Cheilinus fasciatus and Tautoga onitis) represented an intermediate coordination condition, with herbivores (the parrotfishes, Scarus quoyi and Sparisoma radians) at one extreme, and fishes feeding on elusive prey (Epibulus insidiator and Oxycheilinus digrammus) at the other extreme. The analysis suggests that the biomechanical demands of coordination for feeding on benthic invertebrates may represent a generalized, and perhaps ancestral behavior in the wrasses, whereas more specialized trophic niches have evolved divergent, more specialized demands. Examining the movement and coordination of the jaws, fins, and eyes during fish feeding provides a detailed mechanistic basis for behavior, and comparison of coordination patterns during feeding among different taxa can measure how these trophic strategies differ. Understanding the evolution of feeding ecologies in these demersal fishes may have implications for understanding their role within their shallow water reef community.     

Females learn from mothers and males learn from others. The effect of mother and siblings on the development of female mate preferences and male aggression biases in Lake Victoria cichlids, genus Mbipia

While species-assortative behaviour is often observed in sympatrically occurring species, there are few examples where we understand the extent to which development of assortative behaviour is genetically or environmentally determined, for instance, through learning. However, the majority of mate choice theory assumes genetic recognition mechanisms. Knowledge about the development of species recognition is important for our understanding of how closely related species can coexist and how this coexistence may have arisen. The ontogeny of female mate choice, for instance, may critically influence the degree of assortative mating under many circumstances. Also, male assortative aggression behaviour may affect fitness and the possibility for coexistence of two closely related species. Here, we test whether male aggression biases and female mate preferences of two Lake Victoria rock cichlid species, Mbipia mbipi and Mbipia lutea, are affected by experience. With an interspecific cross-fostering experiment, we test for the effect of experience with the phenotype of the mother and that of the siblings on species-assortative mate preferences and aggression biases. We demonstrate that female mate preferences are strongly influenced by learning about their mothers’ phenotype but not by experience with their siblings, despite ample opportunity for interactions. Male aggression biases, in contrast, are affected by experience with siblings but not by learning about their mothers’ phenotype. We suggest that the development of assortative behaviour of females, but not of males, creates favourable conditions for sympatric speciation in Lake Victoria cichlids.     

A RISK-BASED APPROACH FOR FLOOD CONTROL OPERATION OF A MULTIPURPOSE RESERVOIR1

ABSTRACT: Many approaches are available for operation of a multipurpose reservoir during flood season; one of them is allocation of storage space for flood control. A methodology to determine a reservoir operation policy based on explicit risk consideration is presented. The objective of the formulation is to maximize the reservoir storage at the end of a flood season while ensuring that the risk of an overflow is within acceptable limits. The Dynamic Programming technique has been used to solve the problem. This approach has been applied to develop operation policies for an existing reservoir. The performance of the policy was evaluated through simulation and was found to be satisfactory.