A survey to determine levels of chlorinated pesticides and PCBs in mussels and seawater from the Mid-Black Sea Coast of Turkey

A mussel and seawater monitoring survey was conducted at six sampling points between Yalikoy (Ordu) and Sinop in 1999-2000 along the Mid-Black Sea Coast of Turkey in order to assess concentrations of organochlorine pesticides (OCs) and polychlorinated biphenyls (PCBs). Chlorinated pesticides and PCBs were measured in the mussel Mytilus Galloprovincialis and in seawater. In the mussel samples, the most common pollutants in terms of average concentration per g of wet weight (ww), were DDT (max. 1800 pg/gww, min. 240 pg/gww) and its metabolites DDD (max. 5400 pg/gww, min. 240 pg/gww) and DDE (max. 2800 pg/gww, min. 70 pg/gww). Also, dieldrin, heptachlor and HCB were notable contaminants in the mussel samples. PCBs were determined in none of the biota or seawater samples. The concentrations of the OCs and PCBs in mussels were higher in coastal areas receiving river discharges and close to the largest city of the region, Samsun (especially in sampling points in the harbour area). The well-known long persistence of DDTs and other chlorinated compounds was confirmed by residues of these pollutants measured in mussels. On the other hand, even though the usage of such kind of persistent compounds in Turkey was banned, there may still be illegal usage and it is not certain whether the application of these compounds did end in the region.     

SHORT COMMUNICATION PRINCIPAL COMPONENT ANALYSIS AND POLLUTION BY TRACE ELEMENTS IN A MUSSEL SURVEY

The total content of nine trace elements(Mn,Fe,Co,Ni,Cu,Zn,Cd,Hg,Pb)in the soft part of mussels(Mytilus galloprovincialis Lamarck)sampled in two sites was considered.Wild,polluted molluscs weresampled in Muggia Bay(Gulf of Trieste,Northern Adriatic Sea)in the proximity of an important sewerof the city.Edible,unpolluted mussels were simultaneously sampled in a hatchery just off the Bay.Principal component analysis has been applied to correlation matrices obtained from data matrices fromthe literature.The nine variables were reduced to three or two principal components,which explained70-80% of the total variance.The unrotated and orthogonally rotated matrix of the correlations ofvariables with principal components showed that the clusters of elements are positively associated to thefirst two eigenvectors.The origin of some toxic elements in the soft part of mussels from Muggia Bay isdiscussed.The projection on the first two eigenvectors of all data as component scores allow a nearlycomplete separation of polluted from unpolluted molluscs.     

嵊泗列岛海域三种贻贝贝体框架特征的差异

以壳长SL、壳宽SW、壳高SH(BD)、OA(壳顶至韧带末端的直线距离)、OB(壳顶至壳背面最高点的直线距离)、OC(壳顶至壳后端最远点的直线距离)、OD(壳顶至壳高性状在腹缘的落点的直线距离)、AB(韧带末端至壳背缘最高点的直线距离)、BC(壳背缘最高点至壳后端最远点的直线距离)、CD(壳后端最远点至壳高性状在腹缘的落点的直线距离)为贝体框架变量,采用多元分析方法系统比较了嵊泗列岛海域厚壳贻贝、紫贻贝和"杂交贻贝"贝体框架特征的差异,结果表明:(1)在所涉9项贝体框架特征指标中,紫贻贝与厚壳贻贝间无显著差异的指标仅为L5(OC/SL)和L7(AB/SL)(P0.05),而"杂交贻贝"各项指标则均与厚壳贻贝和紫贻贝具显著差异(P0.05),厚壳贻贝和紫贻贝变异系数大于10%的指标均仅为L7(AB/SL),而"杂交贻贝"则仅为L3(OA/SL);(2)厚壳贻贝与紫贻贝间的欧氏距离最短(P0.05),仅为0.160;厚壳贻贝与"杂交贻贝"间和紫贻贝与"杂交贻贝"间的欧氏距离相近(P0.05),分别为0.452和0.418;(3)经主成分分析,提取到的3个特征值均大于1的主成分,累计贡献率达82.928%,其中第一主成分、第二主成分、第三主成分可依次归为与滤食功能区水平剖面占比相关的贝体框架因子,与消化功能区水平剖面占比相关的贝体框架因子,和与消化功能区垂直剖面占比相关的贝体框架因子,通过第一主成分仅能较清晰地区分厚壳贻贝和"杂交贻贝";(4)采用逐步判别法,以判别贡献率较大的L1(SW/SL)、L3(OA/SL)、L4(OB/SL)、L5(OC/SL)、L6(OD/SL)和L7(AB/SL)为自变量,所建Fisher分类函数方程组可较清晰区分厚壳贻贝、紫贻贝和"杂交贻贝",三者的判别准确率依次为94.6%、94.6%和100%,综合判别准确率为96.4%。     

Relationships between daily growth of different groups of swordtip squid (Uroteuthis edulis) and environmental variables in the East China Sea

Swordtip squid (Uroteuthis edulis) is one of the important economical fishing target species in the East China Sea. Uroteuthis edulis is characterized by rapid growth, extensive migration, and long spawning period and sensitive to surrounding environment. In order to assess its stock status, it is necessary to explore its spawning season, growth patterns of different populations and their relationship with the environment in advance. In this paper, based on the samples of U. edulis collected in the East China Sea from September 2017 to March 2018, we explored the relationships between daily growth of statolith microstructure and environmental variables by gradient forest method and generalized additive model. The spawning season of U. edulis was found to be nearly one year, and two dominant season groups were found: the spring group with the peak period of April and the summer group with the peak period of August. Water temperature in the depth of 25 m (Temp_25), sea surface temperature (SST) and zonal velocity were the key environmental variables for the daily growth of April-spawning group. The most suitable environmental conditions for the growth of April-spawning group were water temperature (24?27°C) and velocity (0.1?0.3 m/s). SST, Temp_25 and mixed layer depth were the key environment variables for the daily growth of August-spawning group. The most suitable environmental conditions for the growth of August-spawning group were water temperature (21?28°C) and water depth (0?50 m). Key environmental variables of different groups suggested that early growth was significantly affected by seasonal changes of water temperature, current velocity and prey abundance. This study explored the relationships between early growth and environmental variables and provided the scientific guidance for the management and conservation of U. edulis.     

厚壳贻贝(Mytilus coruscus)金属硫蛋白MT-10:cDNA克隆、结构分析及铜离子胁迫下的表达

近年来我国沿海海域重金属污染日趋严重,软体动物尤其是双壳贝类响应重金属污染胁迫的研究发展成为目前的研究热点。金属硫蛋白是一类广泛存在于生物体内富含半胱氨酸(Cys)的小分子蛋白,具有结合金属离子的能力,能有效调节生物体细胞内的金属离子平衡,具有清除自由基,重金属解毒的功能,关于厚壳贻贝MT蛋白的研究尚未见报道。本文首次利用RT-PCR和c DNA末端快速扩增技术克隆了厚壳贻贝MT-10蛋白c DNA全长(Mc-MT-10),其包含101bp的5′UTR区,108bp的3′UTR区以及222bp的ORF区,编码73个氨基酸。经比对发现Mc-MT-10富含Cys,且具有9个软体动物中常见的CXC结构以及CKCXXXCXCX结构,系统进化树中同科或属中MT-10聚合成一个分支,显示出高度保守性。采用Q-PCR技术分析了MT-10 mRNA在Cu~(2+)胁迫下厚壳贻贝外套膜及消化腺中表达变化,结果表明Mc-MT-10 mRNA在Cu~(2+)胁迫下两种组织中的表达量急剧升高,说明Cu~(2+)能够诱导Mc-MT-10 mRNA的表达,并且表现出诱导具有阈值性特点。研究结果可为深入研究厚壳贻贝MT蛋白的功能奠定基础,为厚壳贻贝抗重金属污染新品种选育提供数据支持。