磷浓度对２种有毒亚历山大藻生长和产毒力的影响

采用显微镜细胞计数和标准藻毒监测方法—小鼠生物法,研究了4种磷浓度0µmol•L-1、1.8µmol•L-1、3.6µmol•L-1和5.4µmol•L-1对有毒甲藻塔玛亚历山大藻(Alexandrium tamarense)和微小亚历山大藻(Alexandtium minutum)的生长和产毒力的影响。结果表明,磷浓度对两种甲藻的生长和产毒能力都有显著性影响(p<0.05)。3.6µmol•L-1磷浓度组的塔玛亚历山大藻密度显著高于其它3个磷浓度组,0µmol•L-1磷浓度组显著低于其它3个磷浓度组。微小亚力山大藻在1.8µmol•L-1、3.6µmol•L-1和5.4µmol•L-1磷浓度下生长没显著性差异(p>0.05)。但在0µmol•L-1磷浓度下生长缓慢,藻密度显著低于其它3个有磷组。0µmol•L-1磷浓度下塔玛亚历山大藻和微小亚历山大藻的产毒能力最高, 显著高于其它磷浓度组(p<0.05),分别为3 MU•10000cells-1和5.2MU•10000cells-1。其它磷浓度组两种有毒甲藻的产毒能力没有显著性差异(p>0.05)。     

青岛近岸水域挥发性酚的分布及在贝类体内的积累

根据１９９８年４－１０月对青岛市近岸水域及贝类养殖区的综合调查结果,初步摸清了青岛市近岸水域及贝类体内酚的分布。在所调查的水域内酚的含量范围为０－８．１１μｇ／Ｌ,平均值为１．５５μｇ／Ｌ。     

对贝类产品标准中重金属限量指标的探讨

对我国现行的国家标准、行业标准及国外相关标准中有关贝类重金属的指标进行比较分析。在此基础上,结合我国目前贝类卫生状况调查结果以及国内外文献资料,对我国贝类标准中的重金属限量进行探讨,提出我国贝类标准中重金属的建议限量指标为:汞0.5 mg/kg,无机砷1.0 mg/kg,铅1.5 mg/kg,镉2.0 mg/kg(不包括牡蛎、扇贝、泥蚶),铜50 mg/kg,铬2.0 mg/kg。     

河北省海域贝类养殖区生态环境质量评价研究

[目的]加强贝类养殖环境的保护,保障水产食品的卫生安全。[方法]根据2009年10月同步进行河北省海域贝类养殖区海水、沉积物和养殖贝类质量的调查资料,采用海水质量评价指数、表层沉积物质量评价指数和养殖贝类质量评价指数以及贝类养殖生态环境质量综合评价对河北省海域贝类养殖生态环境质量进行了综合评价。[结果]海水质量、表层沉积物质量和养殖贝类质量水平平均为2级、5级和4级,总体分别处于较好、差和较差水平,贝类养殖区生态环境质量平均为3级,总体处于一般水平,其主要污染物为PO43-、DIN、大肠菌群,同时不同养殖区生态环境质量差异明显,其中浅海养殖区生态环境质量较好,为1类区,适合养殖贝类;潮间带养殖区生态环境质量较差,为3类区,不适合贝类养殖。[结论]除浅海养殖区外,河北省海域贝类养殖区生态环境亟待改良。     

贝类食物中膝沟藻毒素快速筛选方法研究

为了建立了一种贝类食物中膝沟藻毒素快速筛选方法.将样品用0.05 mol/L的盐酸提取膝沟藻毒素,阴离子柱净化提取液,柱前衍生化反应后在波长为310nm的紫外灯下观察有无荧光产生,快速筛选贝类食物中的膝沟藻毒素.结果表明,衍生化产物在避光条件下30 min内保持稳定,当膝沟藻毒素添加量为0.8 mg/kg时,荧光现象明...     

贝类单孢子虫PCR检测方法的建立

根据基因库中单孢子虫的基因保守序列,设计了1对特异性引物,通过对PCR扩增条件的优化,建立了检测贝类单孢子虫的PCR方法。用该方法对单孢子虫模板进行扩增,得到与试验设计相符的244 bp的特异性条带,而对派琴虫、折光马尔太虫、嗜水气单胞菌、荧光假单胞菌、副溶血弧菌、溶藻弧菌、河弧菌和拟态弧菌等病原体的扩增结果全为阴性。敏感性试验结果表明,该方法最低能检测到100 fg的单孢子虫DNA。     

象山港南沙岛不同养殖模式沉积物微生物群落结构分析

通过构建16S rDNA克隆文库对象山港南沙岛不同养殖模式(贝类养殖、藻类养殖及网箱养殖)表层沉积物微生物多样性和群落结构特征进行了比较和分析,共获取136个OUT。其中,贝类养殖区、藻类养殖区和网箱养殖区OTU分别为58、48和57个。各站位OTU分布差异明显,表现出高度的多样性。基于16S rDNA序列的生物多样性和丰富度分析表明,网箱养殖区丰富度指数ACE为739,香浓指数H?为3.8,均为最高值,丰富度指数Chao为245,略低于于贝类养殖区。贝类养殖区丰富度指数Chao为303,在各养殖区中最高。藻类养殖区丰富度指数ACE为174、Chao为89,香浓指数H?为3.6,均为最低值。系统发育分析表明,南沙岛各养殖区的优势种群均为变形菌门(Proteobacteria),但是藻类养殖区微生物群落结构与其他养殖区域相比,16S rDNA克隆文库差异显著,其中根瘤菌属(Rhizobium)及其他光合细菌在藻类养殖区分布较多。网箱养殖区沉积物表层微生物群落中出现了与环境污染密切相关的菌群,如志贺氏菌属(Shigella)、埃希氏菌属(Escherichia)和ε-变形菌纲的微生物种群,揭示网箱养殖对底质沉积物环境的影响较大。     

河北省近岸贝类中麻痹性贝毒污染特征及风险评估

自2016年河北省发生贻贝中麻痹性贝毒(paralytic shellfish toxins, PSTs)超标且中毒事件以来,该区域主产贝类中PSTs安全风险受到研究者和管理部门的密切关注。以2022年3—6月在河北省近岸采集的6种主产贝类为研究对象,采用液相色谱质谱联用法(LC-MS/MS法)分析了PSTs的残留状况并进行急性暴露评估,以了解河北省近岸贝类中PSTs污染的变化情况及消费风险。整体来看,不同贝类样品中均有PSTs检出,且4月份贝类样品风险最高,但所有样品均未超过安全限量标准;该区域贝类中PSTs主要组分为GTX1&4和GTX2&3,且紫贻贝(Mytilus galloprovincialis)中含量最高,其次为毛蚶(Scapharca subcrenata);采用最高含量进行急性暴露评估发现,所有贝类样品均处于安全可接受状态。虽然河北近岸贝类中PSTs最高含量呈降低趋势,但仍存在一定残留及安全风险,后续需持续围绕该海域进行长期性调查研究,为我国贝类毒素监管和食用安全提供基础参考数据。     

Ultrafiltration to secure shellfish industrial activities: Culture of microalgae and oyster fertilization

Shellfish farming, a key sector of French aquaculture activity, allows the production of oyster spat in a controlled environment. Their production in commercial hatcheries requires control over the quality of the seawater used to sustain crossbreeding, breeding, and the production of fodder microalgae. Therefore, improving the filtration conditions of incoming water is crucial in ensuring the sustainability of production. An ultrafiltration pilot plant was therefore installed at Vendée Naissain. This ultrafiltration pilot plant allows filtration at 0.02 µm; it is used upstream of hatcheries to eliminate pathogens and parasites that can influence the development of cultivated species and downstream to remove oyster gametes in hatchery effluents. The objectives of this work were: (i) to use ultrafiltered seawater for the culture of the microalga Isochrysis lutea (T-Iso) to determine whether better growth than that observed with borehole water, historically used by the producer, can be achieved; and (ii) to determine whether the use of ultrafiltered water results in better fertilization rates of the cupped oyster Crassostrea gigas compared to filtered and UV-treated seawater. Ultrafiltered water has shown definite efficiency for culturing T-Iso with rapid growth and significant reduction in contamination compared to cultivation in well water. The contribution of ultrafiltered water in hatching is more nuanced; ultrafiltered water does not stabilize hatch rates, and its quality is highly dependent on the quality of the seawater used.     

Design and operation of a low-cost and compact autonomous buoy system for use in coastal aquaculture and water quality monitoring

The need to ensure future food security and issues of varying estuarine water quality is driving the expansion of aquaculture into near-shore coastal waters. It is prudent to fully evaluate new or proposed aquaculture sites, prior to any substantial financial investment in infrastructure and staffing. Measurements of water temperature, salinity and dissolved oxygen can be used to gain insight into the physical, chemical and biological water quality conditions within a farm site, towards identifying its suitability for farming, both for the stock species of interest and for assessing the potential risk from harmful or toxic algae. The latter can cause closure of shellfish harvesting. Unfortunately, commercial scientific monitoring systems can be cost prohibitive for small organisations and companies to purchase and operate. Here we describe the design, construction and deployment of a low cost (<£ 5000) monitoring buoy suitable for use within a near-shore aquaculture farm or bathing waters. The mooring includes a suite of sensors designed for supporting and understanding variations in near-shore physical, chemical and biological water quality. The system has been designed so that it can be operated and maintained by non-scientific staff, whilst still providing good quality scientific data. Data collected from two deployments totalling 14 months, one in a coastal bay location, another in an estuary, have illustrated the robust design and provided insight into the suitability of these sites for aquaculture and the potential occurrence of a toxin causing algae (Dinophysis spp.). The instruments maintained good accuracy during the deployments when compared to independent in situ measurements (e.g. RMSE 0.13–0.16 °C, bias 0.03–0.08 °C) enabling stratification and biological features to be identified, along with confirming that the waters were suitable for mussel (Mytilus spp.) and lobster (Homarus gammarus) aquaculture, whilst sites showed conditions agreeable for Dinophysis spp.