The Risk Assessment for Sourcing Seafood (RASS): Empowering businesses to buy responsibly     

《Marine Policy》2017

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Jellyfish blooms perception in Mediterranean finfish aquaculture     

《Marine Policy》2017

In recent years, negative impacts of jellyfish blooms (JB) on marine human activities have been increasingly reported. Aquaculture has been affected by jellyfish outbreaks, mostly documented through repeated episodes of farmed salmon mortalities in Northern Europe; however, the valuation of JB consequences on the aquaculture sector still remains poorly quantified. This study aims to provide the first quantitative evaluation effects of JB on finfish aquaculture in the Mediterranean Sea and to investigate the general awareness of JB impacts among Mediterranean aquaculture professional workers. The aquaculture workers' perception about JB was assessed through a structured interview-based survey administered across 21 aquaculture facilities in central and western Mediterranean. The workers' awareness about JB impacts on aquaculture differed among countries. Italian and Spanish fish farmers were better informed about jellyfish proliferations and, together with Tunisian farmers, they all recognized the wide potential consequences of JB on sea bream and sea bass aquaculture. On the contrary, the majority of Maltese respondents considered JB as a non-significant threat to their activity, mostly based on off-shore tuna farming. This study for the first time shows that JB may negatively affect different Mediterranean aquaculture facilities from Tunisia (Sicily Channel) and Spain (Alboran Sea), by increasing farmed fish gill disorders and mortality, clogging net cages, or inflicting painful stings to field operators, with severe economic consequences. Available knowledge calls for the development of coordinated preventive plans, adaptation policies, and mitigation countermeasures across European countries in order to address the JB phenomenon and its impacts on coastal water activities.  相似文献   

Seasonal variations in phytoplankton biomass and primary production in the Ethiopian Rift Valley lakes Ziway, Awassa and Chamo – The basis for fish production     

Girma Tilahun  Gunnel Ahlgren 《Limnologica》2010,40(4):330-342

Seasonal variations in the biomass (Chl a) and primary production (¹⁴C-method) of phytoplankton were studied during 12 months of 2005 in the three Ethiopian Rift Valley Lakes (ERVL) Ziway, Awassa and Chamo. Chl a showed an average value of 40, 20, and 30 mg m⁻³ for the three lakes, respectively. Integrated areal primary production for the total phytoplankton (g C m⁻² d⁻¹) varied 2-fold in the three lakes but on different levels, from 0.67–1.8 in L. Ziway, 1.8–4.6 in L. Awassa, and 1.0–2.6 in L. Chamo. The overall photosynthetic efficiency of utilizing photosynthetically active radiation by the phytoplankton on molar basis (mmol C mol of photons⁻¹) resulted in an average value of 1.4 for L. Ziway, 3.5 for L. Awassa and 1.6 for L. Chamo. Among the different factors regulating phytoplankton primary productivity, light penetration and nutrients were the most important in the three lakes. The seasonal variations of incident radiation (most values between 5 and 7 E m⁻² h⁻¹) and water temperature (most values between 22 and 24 °C) were small and unlikely to result in the marked differences in phytoplankton primary production. Although relative increase in nutrient concentrations occurred following the rainy periods, the major algal nutrients were either consistently low (nitrate and/or silicate) or high (phosphate and/or ammonium) and remained within a narrow range for most of the study period in all the three lakes. Consequently, phytoplankton biomass and primary production seem to be maintained more by nutrient regeneration or turnover (facilitated by high temperature) than by allochthonous nutrient input. This would be coupled with wind-induced mixing that would play an important role in determining hydrographic characteristics (water column structure) and the associated redistribution of nutrients and phytoplankton, the availability of light and subsequently the spatial (vertical) and temporal patterns of phytoplankton production in these three ERVL. Phytoplankton production (PP) is regarded as a good predictor of fish yield in lakes and seasonal measurements of PP is a prerequisite for good such estimates.  相似文献   

Assessing estuarine environmental quality using fish-based indices: performance evaluation under climatic instability     

Martinho F  Viegas I  Dolbeth M  Leitão R  Cabral HN  Pardal MA 《Marine pollution bulletin》2008,56(11):1834-1843

The seasonal variation of five selected multimetric indices for the determination of the Ecological Quality Status (EQS) of transitional waters was evaluated, as well as the indices’ responses to an extreme drought event that occurred in 2005. The database used regards the Mondego River estuary, which was sampled from June 2003 to August 2006 on a monthly basis. Among the selected indices (EBI - Deegan et al. [Deegan, L., Finn, J.T., Ayvazlan, S.G., Ryder-Kieffer, C.A., Buonaccoesi, J., 1997. Development and validation of an Estuarine Biotic Integrity Index. Estuaries 30(3), 601-617], EDI - Borja et al. [Borja, A., Franco, J., Valencia, V., Bald, J., Muxika, I., Belzunce, M.J., Solaun, O., 2004. Implementation of the European Water Framework Directive from the Basque Country (northern Spain): a methodological approach. Marine Pollution Bulletin 48(3-4), 209-218], EFCI - Harrison and Whitfield [Harrison, T.D., Whitfield, A.K., 2004. A multi-metric fish index to assess the environmental condition of estuaries. Journal of Fish Biology 65, 683-710], EBI - Breine et al. [Breine, J.J., Maes, J., Quataert, P., Van den Bergh, E., Simoens, I., Van Thuyne, G., Belpaire, C., 2007. A fish-based assessment tool for the ecological quality of the brackish Scheldt estuary in Flanders (Belgium). Hydrobiologia 575, 141-159] and TFCI - Coates et al. [Coates, S., Waugh, A., Anwar, A., Robson, M., 2007. Efficacy of a multi-metric fish index as an analysis tool for the transitional fish component of the Water Framework Directive. Marine Pollution Bulletin 55, 225-240]), the EBI by Breine et al. (2007) was the only that evidenced clear interannual and seasonal variations. The EQS by the several indices ranged from “Low” to “High”, depending on the index considered, evidencing the high level of mismatch between indices. The results are discussed in the scope of the EU Water Framework Directive, regarding monitoring strategies, application of indices and EQS assessment.  相似文献   

Organochlorine pesticides in fish from the southern Baltic Sea: levels, bioaccumulation features and temporal trends during the 1995-2006 period   总被引：1，自引：0，他引：1  

Szlinder-Richert J  Barska I  Mazerski J  Usydus Z 《Marine pollution bulletin》2008,56(5):927-940

The levels of HCH isomers, HCB and summation DDTs were determined in five species of Baltic fish collected during 1995-2006. Some downward time trends of HCH isomer, pp'-DDE and pp'-DDD concentrations in Baltic fish were observed; in contrast, HCB and DDT concentrations did not exhibit any obvious trend. Concentrations of summation HCHs expressed on a lipid weight basis were very similar in all species studied. In contrast, concentrations of summation DDTs varied in tested species. The most abundant HCH isomer was beta-HCH and among DDT-related compounds, pp'-DDE prevailed. In our investigations the sampling sites were not a crucial factor for organochlorine pesticide concentrations and patterns observed in fish, but the occurrence of several inter-species differences in the bioaccumulation features of OC pesticides were observed. For cod there was a positive correlation between fish size (length) and summation DDT concentration. In herring, sprat and salmon samples, summation DDT concentrations were negatively correlated with fat content.  相似文献   

Are steroids really the cause for fish feminization? A mini-review of in vitro and in vivo guided TIEs   总被引：1，自引：0，他引：1  

Schlenk D 《Marine pollution bulletin》2008,57(6-12):250-254

Feminization of fish has been reported throughout the world in freshwater and marine systems. While the population impacts are conflictive, enough negative effects warrant additional research into causation. In order to ascertain the identities of specific feminizing agents, variants of toxicity identification evaluations (TIEs) have been employed. The majority of these evaluations have utilized in vitro estrogen receptor-based cell-lines to identify chromatographic fractions that possess biological activity from predominately wastewater derived from municipal treatment facilities and have concluded that synthetic and natural estrogens are the primary cause for feminization of fish. This paper will focus on three aquatic systems impacted by wastewater originating from purely domestic, and industrial/domestic secondary treatment systems. Wastewater and sediment extracts were evaluated by in vitro and in vivo biological responses in a TIE fractionation design. While in vitro responses tended to mirror in vivo responses in purely domestic wastewater systems, in vitro responses tended to severely underestimate in vivo estrogenic activity when normalized to estradiol equivalents in more complex systems. TIE fractionation schemes using in vivo biological responses failed to indicate any relationship to steroids in either wastewater or sediment extractions. These data consistently support the view that mechanisms other than direct ER binding and activation by toxicants may be important in the feminization of fish particularly residing in habitats that receive complex wastewater or agricultural effluents.  相似文献   

Population biology of coral trout species in eastern Torres Strait: Implications for fishery management     

Ashley J. Williams  Leanne M. Currey  Gavin A. Begg  Cameron D. Murchie  Aaron C. Ballagh 《Continental Shelf Research》2008

Coral trout (Plectropomus spp.) are the main target species for commercial fishers in the eastern Torres Strait Reef Line Fishery (ETS RLF). The four species of coral trout known to occur in Torres Strait: Plectropomus leopardus, Plectropomus maculatus, Plectropomus areolatus and Plectropomus laevis are currently managed as a single species in Torres Strait, as there is no species-specific biological information available for the region which could be used to assess whether species differ in their response to fishing pressure. The aim of our study was to determine whether it is appropriate (biologically) to manage coral trout in the ETS RLF as a single species group or whether different management arrangements are required for some species. We used catch data and biological data from samples collected by commercial fishers to examine the distribution within Torres Strait and estimate a range of biological parameters for P. leopardus, P. maculatus and P. areolatus. Insufficient P. laevis samples were collected to reliably examine this species. Results indicated that the population biology, particularly the reproductive biology, of P. areolatus was substantially different to both P. leopardus and P. maculatus. Although it is difficult to predict the response to fishing, P. areolatus may be more vulnerable to fishing than P. leopardus and P. maculatus, due to the larger size at sex change observed for this species and the very low proportion of males protected by the current minimum size limit. Therefore, while the common management arrangements for P. leopardus and P. maculatus appear to be adequate for these species, separate management arrangements are needed for the sustainable harvest of P. areolatus populations in the ETS. Specifically, we recommend the introduction of a maximum size limit for P. areolatus, in addition to the current minimum size limit, which may allow a proportion of males some protection from fishing.  相似文献   

南京玄武湖鱼类暴发性死亡原因分析     

王国祥  夏忠林  方东 《湖泊科学》1997,9(1):41-48

南京玄武湖近年来死鱼事件频发,对该湖水生生态系统的长期监测结果表明,湖水富营养化和沉积物污染十分严重。但生礅毒理学研究表明,湖水和沉积物等对鱼类尚未见有急性毒性作用,根据玄武湖鱼类死亡症状,从玄下湖鱼体上分离到一种致力极强的鱼类病原菌－－嗜水气单胞菌,研究了该病原菌的至病特性,并系统地分析了水质主要污染指标,水体富化,藻类种群动态,沉积的污染及其氧化还原层等多种因素对玄武涌鱼类暴发性死亡的发生和流  相似文献   

我国8个水电站15种过鱼对象游泳能力研究     

柯森繁  金志军  李志敏  雷青松  王永猛  石小涛  涂志英 《湖泊科学》2022,34(5):1608-1619

近几年我国水电站过鱼设施设计已将过鱼对象游泳能力作为重要参考. 以我国8个水电站主要过鱼对象为研究目标,在野外实验设施条件下测试了15种鱼(四大家鱼组、裂腹鱼组和鳅组)的感应流速和爆发游泳速度. 采用多元线性回归法分别分析了各组鱼体长及水温对游泳能力的影响,并构建了优化的游泳能力预测模型. 结果表明,四大家鱼组、裂腹鱼组和鳅组的感应流速和爆发游速皆与体长呈负相关,感应流速与水温也皆呈负相关关系. 水温升高使四大家鱼组和裂腹鱼组的爆发游速能力增强,而水温对鳅组鱼的爆发游速影响不大,可能与鳅科鱼类特殊的腹部吸附行为有关. 利用绘制的鱼感应水流和爆发未疲劳的数量百分比的生存曲线进行上行及下行过鱼设施流速设计. 结果表明：当鱼感应水流的数量百分比为90 % 时,四大家鱼、裂腹鱼和鳅组幼鱼感应流速分别为3.00、1.67和3.22 BL/s,裂腹鱼和鳅组成鱼感应流速分别为1.27和2.09 BL/s;当鱼爆发未疲劳的数量百分比为90 % 时,四大家鱼、裂腹鱼和鳅组幼鱼爆发游泳速度分别为8.13、9.27和9.61 BL/s,裂腹鱼和鳅组成鱼爆发游泳速度分别为7.64和7.77 BL/s. 当以裂腹鱼或鳅成鱼为主要过鱼对象时,上行过鱼设施内流速范围建议为1.27~7.64和2.09~7.77 BL/s. 当以四大家鱼、裂腹鱼或鳅幼鱼为主要过鱼对象时,下行过鱼设施入口流速建议小于8.13、9.27和9.61 BL/s. 本研究结果可为我国水电站主要过鱼对象的过鱼设施设计提供参考依据.  相似文献   

Mercury contamination in Southern New England coastal fisheries and dietary habits of recreational anglers and their families: Implications to human health and issuance of consumption advisories     

David L. Taylor  Patrick R. Williamson 《Marine pollution bulletin》2017,114(1):144-156

Total mercury (Hg) was measured in coastal fishes from Southern New England (RI, USA), and Hg exposure was estimated for anglers and family members that consumed these resources. Fish Hg was positively related to total length (n = 2028 across 7 fish species), and interspecies differences were evident among legally harvestable fish. Many recreational anglers and their families experienced excessively high Hg exposure rates, which was attributed to the enriched Hg content of frequently consumed fishes. Specifically, 51.5% of participants in this study had Hg exposures exceeding the US EPA reference dose, including 50.0% of women of childbearing years. These results are noteworthy given that Hg neurotoxicity occurs in adults and children from direct and prenatal low-dose exposure. Moreover, this study underscores the need for geographic-specific research that accounts for small-scale spatial variations in fish Hg and dietary habits of at-risk human populations.  相似文献