Assessment of sediment concentration and nutrient loads in effluents drained from extensively managed fishponds in France

Expansion of aquaculture has increased concern over its environmental impact. The composition of effluents from intensive aquaculture is well documented, but few data on extensive aquaculture are available. During 12 draining operations, 523 water samples were collected downstream from six extensively-managed fishponds in northeastern France. Study ponds had surface areas of 2-620 ha and were managed for production of Cyprinids and Percids. Concentrations of total suspended solids, total phosphorus, and Kjeldahl nitrogen in effluents from the ponds were greatest during the final stage of draining. Loads of phosphorus were higher than those reported for effluents of more intensive aquaculture ponds in the USA, but the source of the potential pollutants was catchments and sediment rather than feeds and fertilizer. It will be necessary to reduce the water drawdown rate during the fishing stage and possibly implement other best management practices to prevent the TSS concentration from exceeding 1 g/L.     

Positive Interactions Between Irrawaddy Dolphins and Artisanal Fishers in the Chilika Lagoon of Eastern India are Driven by Ecology,Socioeconomics, and Culture

In human-dominated landscapes, interactions and perceptions towards wildlife are influenced by multidimensional drivers. Understanding these drivers could prove useful for wildlife conservation. We surveyed the attitudes and perceptions of fishers towards threatened Irrawaddy dolphins (Orcaella brevirostris) at Chilika Lagoon India. To validate the drivers of fisher perceptions, we : (1) observed dolphin foraging behavior at stake nets, and (2) compared catch per unit effort (CPUE) and catch income of fishers from stake nets in the presence and absence of foraging dolphins. We found that fishers were mostly positive towards dolphins, believing that dolphins augmented their fish catch and using culture to express their perceptions. Foraging dolphins were observed spending half their time at stake nets and were associated with significantly higher catch income and CPUE of mullet (Liza sp.), a locally preferred food fish species. Wildlife conservation efforts should use the multidimensional drivers of human–wildlife interactions to involve local stakeholders in management.     

Polychlorinated biphenyls (PCBs) in marine fishes from China: Levels, distribution and risk assessment

Muscle tissues of large yellow croakers (Pseudosciaena crocea) and sliver pomfret (Pampus argenteus) from nine coastal cities of East China including Dalian, Tianjin, Qingdao, Shanghai, Zhoushan, Wenzhou, Fuzhou, Quanzhou and Xiamen were analyzed for polychlorinated biphenyl (PCB) concentrations. Thirty-six PCB congeners were quantified in the fishes, of which 11 congeners were dioxin-like PCBs. The total PCB concentrations of the present study were at the low end of the global range, which may be related to the smaller usage and shorter consumption history of PCBs in China. PCBs 18, 29, 52, 66, 101, 104, 138, 153, 180 and 194 were the major constituents found in the fish samples. Regression analysis showed a strong positive correlation (R² = 0.800; p < 0.001) between total dioxin-like PCBs and total PCB concentrations, and that total PCB concentrations explain 80% of the variability in total dioxin-like PCB concentrations. Among the species investigated, significantly higher concentrations of total PCBs were found in croakers than in pomfrets, which may be attributed to their different feeding and living habits. No significant difference in total PCB concentrations among the cities was observed; principal component analysis (PCA) of PCB profiles indicated that PCB pollution came from similar sources in the sampling areas and that there may be other PCB sources in Dalian and Wenzhou. The calculated carcinogenic risks (CRs) from the two species based on a low consumption group and high consumption group were all greater than 10⁻⁶, suggesting that daily exposure to dioxin-like PCBs via fish consumption results in a lifetime cancer risk of greater than one in one million. In contrast, the hazard quotients (HQs) of noncancer risks were all less than unity.     

微波消解-ICP/MS法同时测定鱼肉中的砷和汞

采用微波消解处理鱼肉样品,用电感耦合等离子体质谱法测定样品中砷和汞。通过试验优化微波消解参数、酸体系及赶酸温度,用在线加入内标方法消除基体干扰及仪器漂移对测定的影响。方法在0μg/L～40. 0μg/L范围内线性良好,砷和汞的方法检出限分别为0. 002 mg/kg和0. 001 mg/kg,实际样品6次测定结果的RSD为5. 4%～15. 6%,加标回收率为90. 0%～110%。将该方法用于测定芹菜和扇贝标准物质,测定值在标准值不确定度范围内。     

Kin recognition in rainbowfish (Melanotaenia eachamensis): sex, sibs and shoaling

Living with relatives can be beneficial to individuals via the evolution of kin-directed altruism, but this is tempered by the increased risk of inbreeding. Therefore, in social species, the ability to recognise relatives can be highly advantageous. This study focuses on kin discrimination in the Lake Eacham rainbowfish, Melanotaenia eachamensis, an endangered freshwater species from north-east Queensland, Australia. First, I examined kin recognition abilities when a combination of both chemical and visual recognition cues was available. When given a choice of shoaling with same-sex groups, females spent significantly longer with full-sibs rather than half-sibs, full-sibs rather than non-relatives and half-sibs rather than non-relatives. Males spent significantly longer shoaling with full-brothers versus half-brothers, but showed no other shoalmate preferences. Second, in the presence of only chemical cues, females did not discriminate among groups of different levels of relatedness, but males showed a non-significant tendency to associate with full-sibs rather than non-relatives. Male shoaling behaviour seemed to be more influenced by factors other than relatedness, e.g. intra-sexual competition. Finally, I found that the shoaling preferences of females changed when exposed to groups of males. Females preferred to associate with non-relatives rather than half-brothers and non-relatives rather than full-brothers. There was no significant difference in the time spent with half-brothers versus full-brothers. Taken together, my results suggest that females have very good kin recognition abilities. They prefer to shoal with female relatives but avoid male relatives, and so are able to balance the benefits of nepotism and the costs of incest. Received: 2 May 2000 / Revised: 26 July 2000 / Accepted: 30 July 2000     

南通市近岸海域主要海产品重金属残留监测与评价

对南通市近岸海域捕捞的多获性鱼类6种,甲壳类2种,养殖的贝类7种,藻类2种共17种海产品158份样品重金属残留进行调查分析。采用样品超标率、内梅罗综合污染指数等指标对海产品重金属残留状况进行综合评价,结果表明,南通市近岸海域海产品中人工养殖的贝类、藻类重金属污染大于捕捞的鱼类、甲壳类,重金属及As在海产品中的残留为:Cd、As污染>Pb、Hg、Cu、Cr。     

泉州白濑水利枢纽工程升鱼机进鱼口位置选择研究

水库大坝建设会对鱼类洄游造成阻隔影响,为减少大坝阻隔对鱼类遗传交流的影响,大坝应建设过鱼设施。福建省泉州白濑水利枢纽工程采用升鱼机过鱼设施,而进鱼口位置选择是影响过鱼设施设计成败的关键因素。根据白濑水利枢纽布置特点,从坝下流场、工程条件、过鱼效果等方面进行进鱼口位置比选研究,为类似水库工程过鱼设施进鱼口位置选择提供参考和借鉴。     

鱼类样品中有机磷阻燃剂分析方法的优化研究

建立了鱼类组织样品中有机磷阻燃剂（OPFRs）的分析方法,优化了萃取条件、净化条件、液相色谱条件和质谱检测参数。确定了生物样品经冷冻干燥后,以1∶1（V/V）的正己烷/二氯甲烷混合溶液进行加速溶剂萃取,利用氨基固相萃取柱进行净化,以1∶1（V/V）的正己烷/二氯甲烷、二氯甲烷和9∶1（V/V）的二氯甲烷/甲醇为洗脱液,最后用超高效液相色谱-串联质谱同时对9种OPFRs进行定性定量检测。结果表明,各物质的基质加标回收率均为56.5%~108%,方法的测定下限为0.016~0.104 ng/g （以脂重计）,满足了生物样品中OPFRs的分析检测要求。利用该方法测定了北京和广州市养殖和野生鲫鱼肌肉组织样品,主要的OPFRs同族体为磷酸三正丁酯（TNBP）、磷酸三乙基己基酯（TEHP）、磷酸三（1-氯-2-丙基）酯（TCIPP）和磷酸三氯乙基酯（TCEP）,质量比为5.94~33.7 ng/g（以脂重计）,显示出良好的适用性。     

酚类抗氧化剂及其代谢产物对鱼类的毒性研究进展

简述了水环境中合成酚类抗氧化剂(SPAs)及其代谢产物,SPAs对鱼类的急性毒性效应、发育毒性效应及机制、内分泌干扰毒性效应和机制,以及代谢过程和产物毒性预测。指出,为准确实现对SPAs及其代谢物的化学品管理及生态风险评估,未来研究应聚焦于对合成酚类抗氧化剂及其代谢物在水生生物体内的分布及浓度检测,为该类化合物的生物富集和生物转化研究提供更多的背景资料;开展对SPAs潜在毒性分子机制的研究,并建立起分子水平上的毒理学效应与个体乃至种群水平上的不良后果之间的联系;探究并完善SPAs的代谢机制,并对现已明确的代谢产物（如BHT-Q）开展毒性效应评价。     

Managing Water to Protect Fish: A Review of California’s Environmental Water Account, 2001–2005

The Sacramento-San Joaquin Delta, the landward reach of the San Francisco Estuary, provides habitat for threatened delta smelt, endangered winter-run Chinook salmon, and other species of concern. It is also the location of huge freshwater diversion facilities that entrain large numbers of fish. Reducing the entrainment of listed fishes into these facilities has required curtailment of pumping, reducing the reliability of water deliveries. We reviewed the first 5 years (2001–2005) of the Environmental Water Account (EWA), a program instituted to resolve conflicts between protecting listed fishes and providing a reliable water supply. The EWA provided fishery agencies with control over 0.2–0.4 km³ of water to be used for fish protection at no cost to users of exported water, and fish agencies guaranteed no disruption of water supply for fish protection. The EWA was successful in reducing uncertainty in water supply; however, its contribution to the recovery of listed fishes was unclear. We estimated the effectiveness of the EWA to be modest, increasing the survival of winter-run Chinook salmon by 0–6% (dependent on prescreen mortality), adult delta smelt by 0–1%, and juvenile delta smelt by 2–4%. Allocating EWA water for a single life stage of one species could provide larger gains in survival. An optimally allocated EWA of equal size to the median of the first 5 years could increase abundance of juvenile delta smelt up to 7% in the springs of dry years. If the EWA is to become a long-term program, estimates of efficacy should be refined. If the program is to be held accountable for quantitative increases in fish populations, it will be necessary to integrate scientific, possibly experimental, approaches.