首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
We evaluated whether the trophic level and feeding grounds (coastal versus offshore) of white and shortfin mako sharks captured in the northern Mexican Pacific varied as a function of size using carbon (δ13C values) and nitrogen (δ15N values) stable isotope analysis of soft tissues. A step increase in δ15N values was observed at approximately 85 cm TL and 150–170 cm TL for shortfin mako and white sharks, respectively, consistent with the dilution of the maternal isotopic signal following the incorporation of exogenous food. Shortfin mako and white shark muscle tissue and whole blood were enriched in 15N as a function of size, which is consistent with increasing trophic level, but this pattern may be confounded by differences in habitat. To infer differences in foraging habitat throughout life, we compared isotope ratios of liver and blood fractions with those of white muscle tissue; these tissues have relatively faster and slower isotope turnover rates, respectively. Whole blood and muscle δ13C values of small white sharks (<200 cm total length) caught near the coast suggested benthic foraging. Very limited differences between δ13C values of muscle tissue and whole blood from small and medium mako (<196 cm TL) and small white sharks indicated equilibrium to local feeding grounds. In contrast, differences in the δ13C values of liver tissue from small and medium mako and small white sharks indicated changes in diet or feeding grounds. The δ13C values of plasma and muscle tissue of large white sharks (>350 cm total length) caught offshore indicate feeding in coastal and oceanic areas and are consistent with recent migration to pelagic feeding grounds. Our study provides insight into size‐based habitat use and migration patterns of two species of migratory sharks for which there is limited information, particularly in their nursery grounds in Mexican waters.  相似文献   

2.
In the marine environment, organisms from lower trophic levels seem as a good alternative to the traditional meal and oil sources. In the present study, meals were produced from Antarctic krill (Euphausia superba), Arctic krill (Thysanoessa inermis) and the Arctic amphipod Themisto libellula. Diets were then prepared for Atlantic salmon and Atlantic cod where up to 100% of the fish meal protein was replaced by protein from these organisms. Concentrations of copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb) were determined by ICP-MS in the various krill and amphipod meals, complete diets and muscle samples from fish fed these diets. The element concentrations were related to growth and general fish health as well as present EU legislations on feed ingredients and complete diets. The cod showed no difference in growth during the trial, while salmon fed diets where 40% of the fish meal protein was replaced with Arctic krill or amphipod meal shoved improved SGR during the first period of feeding (first 100 days). No adverse effects on growth rate or fish health were observed in any fish species or treatment. Nevertheless, high levels of Cu were found in the meal from Antarctic krill (46 mg kg− 1 dry matter (dm)) resulting in a dietary level of Cu exceeding the upper limit for complete feedingstuff set by EU. Furthermore, the Cd level found in the meal from amphipod (12 mg kg− 1 dm) was 6 times higher than EU's upper limit. This indicates limitations for the use of certain zooplanktons as alternative protein sources in feed for farmed fish, unless future processing methods yield lower levels of these unwanted elements.  相似文献   

3.
The aim of this study was to analyse the trophic ecology of speckled peacock bass Cichla temensis inhabiting two tributaries of the middle Negro River, the Aracá River and the Demeni River. Using an analysis of stomach contents and stable isotope composition (δ15N, δ13C) of scales, we describe the diet and evaluate the trophic position of subadult and adult individuals. We then test whether diet shifts and trophic positions occurred among successive size classes and among sample locations. The stomach content analysis confirmed the piscivorous feeding habit of the species and showed that the speckled peacock bass preyed on a variety species belonging to different trophic guilds. The length of the ingested prey increased with the size of the speckled peacock bass. Diet composition and trophic position were not different among size classes. δ13C values yielded significant shifts among the size classes: larger individuals displayed higher δ13C values than smaller individuals. Trophic position varied between locations, with lowest values observed in fish from the Aracá River. This study demonstrated that diet of C. temensis may vary according to the size of the fish, even at the subadult or adult stages, and according to the river/locality, even within a same basin. We then suggest that further studies take into account local availability of food resources to better explore C. temensis diet and tropic ecology.  相似文献   

4.
The present status of contamination by heavy metals, and the impact of cage culture on sediments at the Uranouchi Inlet, Kochi Prefecture, Japan, were investigated from two stations influenced by intensive aquaculture and a control station, during May–July 2006. The moisture content of the sediments at the aquaculture stations was over 65%, and the organic matter was always over 100 mg/g dry wt. In contrast, the highest moisture content and organic matter at the control station was 45.5% and 62.9 mg/g dry wt, respectively. Concentrations of zinc (Zn) (178 ± 4.8 mg/kg dry wt) and copper (Cu) (125 ± 1.2 mg/kg dry wt) were highest at the aquaculture stations. Lead (Pb) was highest (50.7 ± 0.77 mg/kg dry wt) at the aquaculture station though it was as high as 33.2 ± 0.77 mg/kg dry wt at the control station. One-way ANOVA showed that the differences in concentrations of Zn and Cu in sediments from the aquaculture and control stations were highly significant (P = 0.01), whereas Pb showed no such trend. Occurrence of a large fraction of labile Zn (56.1%) and Cu (40.3%) in these sediments warrants attention. Although factors other than metals may explain the distribution observed, the information presented here may be useful in predicting long-term effects of heavy metal contamination from aquaculture in the marine environment.  相似文献   

5.
北部湾钦州港近江牡蛎重金属污染分析   总被引:2,自引:0,他引:2  
为近江牡蛎的食用安全及养殖环境监督管理提供科学依据,2015年7—11月在北部湾钦州港采集近江牡蛎样品,利用原子荧光光度计和原子吸收光谱仪测定近江牡蛎体内重金属含量,分析其污染程度。结果显示,调查海域牡蛎体内重金属平均含量从高到低依次为ZnCuCdCrAsPbHg,其中Zn、Cu含量较高,平均值分别为532.03、126.96 mg/kg。Cu参照《无公害食品水产品有毒有害物质限量》(NY 5073-2006),发现除了7月2号站样品未超标,其余样品均超标,超标率达89%。As参照《食品安全国家标准食品中污染物限量》(GB 2762-2012),发现总超标率为11%,仅7月3号站样品存在超标。Pb、Hg含量较低,其平均值分别为0.02、0.009 mg/kg。重金属富集系数揭示近江牡蛎对Zn、Cu、Cd、Cr富集严重。膳食暴露评估方法显示,重金属的膳食摄入量低于联合国粮食和农业组织的食品添加剂联合专家委员会(JECFA)推荐的暂定每周摄入量,钦州湾近江牡蛎属于安全食用范围。  相似文献   

6.
Stable isotope ratios of nitrogen (δ15N) have been used to estimate trophic position (TP) of organisms due to the predictable enrichment of nitrogen-15 in consumer tissues relative to their diet. We explored estimates of trophic position using liver and muscle δ15N and stomach content analysis in a broad size range of Arapaima sp. from Amazonian floodplain lakes. Estimates of TP based on liver δ15N were more closely related to the stomach content data than estimates based on muscle δ15N, possibly because of the higher turnover of nitrogen in liver. Total length and season explained most of the variation in TP values estimated from δ15N, showing that they have more effect than prey trophic position on δ15N values. The TP estimated by identification of stomach content was 3.6 and was unrelated to the size of the arapaima. This highlights the need for a better understanding of the factors that affect values of δ15N and stomach content analysis is still needed to unravel the trophic ecology of predatory fishes.  相似文献   

7.
2014年至2015年,在陕西省的西安市、渭南市、宝鸡市、汉中市、安康市、榆林市和铜川市采集草鱼、鲤、鲫、鲢、鳙、罗非鱼、乌鳢、俄罗斯鲟、鲶、虹鳟和大鲵等11个水产品品种共计274份样品,分别检测Zn、Cu、Hg、As、Cd和Pb 6种重金属(含类金属As)含量。这6种重金属元素在不同水产品肌肉中残留量分别为2.49~25.15、0.1L~2.15、0.000 15L~0.364 3、0.01L~0.161 9、0.000 1L~0.031 5和0.002 5~0.4 mg/kg(鲜重)。6种重金属在11种水产品中的平均含量均低于我国限量标准,综合污染指数等级为Ⅳ级,污染程度属无污染,重金属含量总体状况良好。不同养殖品种间重金属的含量水平有一定差异,大鲵体内Zn的含量水平最高,其次为鲤、鲫、鲶及罗非鱼;鲫体内Cu的含量水平显著高于其它鱼类,其次为鲤;Hg在乌鳢体内含量水平明显较高,其次为大鲵、鲢、鳙和俄罗斯鲟;As在虹鳟体内含量水平最高,其次为俄罗斯鲟和鲢。Cd和Pb的含量在11种水产品间无明显差异。分析结果表明陕西省养殖水产品重金属含量目前虹鳟、俄罗斯鲟、鲢和鳙重金属综合污染指数相对较高,潜在污染风险相对较大,重金属指标中As和Hg的潜在污染风险相对较高。  相似文献   

8.
赤水河主要经济鱼类重金属含量及风险评价   总被引:2,自引:0,他引:2  
为了解赤水河鱼体重金属富集现状及其潜在的生态风险和食品安全,测定了赤水河茅台江段和赤水江段的黄颡鱼(Pelteobagrus fulvidraco)、蛇鮈(Saurogobio dabryi)和大口鲇(Silurus meriordinalis)肌肉和肝脏中的重金属含量。分别使用电感耦合等离子体原子发射光谱法测定Cu、Zn、Pb、Cd、Fe、Cr和Mn的含量,原子荧光光度法测定As和Hg的含量。结果表明:大口鲇肌肉中Cu、Zn、Pb、Cd、Fe、Cr和Hg的含量高于黄颡鱼和蛇鮈,3种鱼类肝脏中的重金属含量均高于肌肉。所有鱼体肌肉中的重金属含量均低于国家标准,但大口鲇肌肉中Pb和Cd的含量高于欧盟委员会标准。危害指数分析表明:赤水河野生鱼类食用的人体健康风险较小。重金属单因子污染指数的结果表明赤水河鱼体Pb和Cd的污染程度较高,赤水河存在潜在的重金属污染风险。  相似文献   

9.
Artemia salina cysts (San Francisco Bay Brand) were exposed in seawater containing multiple concentrations of either a single heavy metal (Hg, Cu, Zn, Pb, Cd, Co, Ni, Cr, Mn and Fe) or combination of heavy metals. The heavy metal accumulation in Artemia nauplii increased linearly with an increase in the heavy metal concentration in water. The metals could be detected in nauplii exposed to a single heavy metal at dosages of 5 μg/L for Hg, Zn, Mn, Fe and Cu; 25 μg/L for Cd and Cr; 50 μg/L for Co; 100 mUg/L for Ni; and 250 μg/L for Pb. Cysts exposed to several heavy metal combinations had minimum effective dosages equal to or lower than the single heavy metals- 5 μg/L for Cu, Cr, Zn, Mn and Fe; 25 μg/L for Cd and Ni; 50 μg/L for Co; and 250 μg/L for Pb. The accumulation of Cu, Ni and Co by Artemiu nauplii did not differ for animals exposed to single or combined heavy metal solutions. Cr, Zn and Pb had a synergistic effect of heavy metal uptake in combined heavy metal element solutions, however, Fe, Cd and Mn had an antagonistic effect.  相似文献   

10.
为了解渤海中部海域沉积物中重金属的污染状况,于2013年8月采集了渤海中部海域34个站点的表层沉积物,检测了Pb、Cd、Hg、Cu、Zn和As 6种重金属的含量,分析了Pb、Cd、Cu和Zn 4种重金属的空间分布特征,采用污染指数法和潜在生态风险评价法对其表层沉积物重金属污染状况进行评价。结果显示,渤海中部海域表层沉积物重金属含量较低,符合海洋沉积物质量(GB 18668-2002)Ⅰ类标准的要求。表层沉积物重金属的空间分布总体呈现由近岸向中心海域降低的趋势。Cu、Zn和Pb含量空间变化趋势比较明显,靠近渤海湾海域重金属含量高,离岸距离越远,重金属含量逐渐降低。Cd含量在靠近黄河入海海域最高,呈现自高值区向东西两边海域减小的趋势。各个站位的重金属单因子污染程度较轻,单因子污染系数均值大小顺序为PbCuZnAsCdHg;重金属综合污染指数都小于5,表现为低污染水平。除1号站位的Hg单因子潜在生态风险系数为54.44之外,其他站位表层沉积物Hg、As、Cu、Zn、Pb和Cd的单因子潜在生态风险系数Eir小于40,范围为0.39~38.80,风险程度由高到低依次为Hg、Cd、As、Pb、Cu和Zn;其综合潜在生态风险系数小于150,范围为16.39~79.57。其中,1号站位综合潜在生态风险系数最高达到79.57。研究表明,此海域属于低潜在生态风险水平,风险指数高值区出现在唐山大清河口海域。  相似文献   

11.
重金属对罗氏沼虾血细胞活性和酯酶活力的影响   总被引:1,自引:1,他引:0  
为探讨不同重金属对罗氏沼虾(Macrobrachium rosenbergii)血细胞的细胞毒性,取罗氏沼虾血淋巴,离体状态下分别暴露于不同浓度(10~(-9)~10~(-3) mol/L)的Cd~(2+)、Hg~(2+)、Cu~(2+)和Zn~(2+)环境中6 h,设置不添加重金属的对照组,应用流式细胞术测定细胞活性和胞内非特异性酯酶活力。结果显示,10~(-9)~10~(-6) mol/L的Cd~(2+)对细胞活性和酯酶活力均没有显著影响,Cd~(2+)浓度达到10~(-5) mol/L时,酯酶活力受到了显著的抑制,Cd~(2+)浓度达到10~(-4)和10~(-3) mol/L时,细胞活性和酯酶活力均显著下降;10~(-9)~10~(-6) mol/L的Hg~(2+)对细胞活性和酯酶活力均没有显著影响,Hg~(2+)浓度为10~(-5)~10~(-3) mol/L时,细胞活性和酯酶活力均显著下降;10~(-9)~10~(-5) mol/L的Cu~(2+)对细胞活性和酯酶活力均没有显著影响,Cu~(2+)浓度为10~(-4)~10~(-3) mol/L时,细胞活性和酯酶活力均显著下降;10~(-9)~10~(-5) mol/L的Zn~(2+)对细胞活性和酯酶活力均没有显著影响,Zn~(2+)浓度为10~(-4) mol/L时,酯酶活力显著下降,Zn~(2+)浓度为10~(-3) mol/L时,细胞活性和酯酶活力均显著下降。Cd~(2+)、Hg~(2+)、Cu~(2+)和Zn~(2+)对细胞活性的毒性临界浓度分别为10~(-4) mol/L、10~(-5) mol/L、10~(-4) mol/L和10~(-3) mol/L,毒性强度由高到低依次为Hg~(2+)、Cd~(2+)、Cu~(2+)、Zn~(2+)。Cd、Hg、Cu和Zn这4种重金属对罗氏沼虾血细胞活性和酯酶活力均具有明显的剂量效应;酯酶活力对重金属胁迫较细胞活性更为敏感,可作为虾类细胞毒理学研究的重要指标。  相似文献   

12.
In mass culture of Pacific bluefin tuna Thunnus orientalis, a marked growth variation is observed after they start feeding at 6–7 mm in body length (BL) on yolk‐sac larvae of other species, and the growth variation in tuna larvae is a factor leading to the prevalence of cannibalism. To examine the relationship between prey utilization and growth variation, nitrogen stable isotope ratios (δ15N) of individual larvae were analysed. A prey switch experiment was conducted under two different feeding regimes: a group fed rotifers (rotifer fed group), and a group fed yolk‐sac larvae of spangled emperor, Lethrinus nebulosus (fish fed group) from 15 days after hatching (6.87 mm BL). The fish fed group showed significantly higher growth than the rotifer fed group. Changes in the δ15N of the fish fed group were expressed as an exponential model and showed different patterns from those of the rotifer fed group. The δ15N of fast‐growing tuna larvae collected in an actual mass culture tank after the feeding of yolk‐sac larvae was significantly higher than those of the slow‐growing larvae, indicating that slow glowing larvae depended largely on rotifers rather than the yolk‐sac larvae.  相似文献   

13.
为探究长江口南支水域表层沉积物重金属元素含量和空间分布变化,分析测定了研究区域2018—2022年表层沉积物中铜(Cu)、锌(Zn)、铅(Pb)、铬(Cr)、镉(Cd)、汞(Hg)及砷(As)的含量,并借助地统计学空间分析方法,对研究区域的重金属元素含量进行变异分析和空间分布模拟。结果显示:Zn、Cr、Cu、Pb、As、Cd、Hg的含量变化范围分别是23.539~101.955 mg/kg、14.390~88.672 mg/kg、3.325~40.441 mg/kg、7.788~26.145 mg/kg、5.035~12.610 mg/kg、0.072~0.436 mg/kg、0.004~0.171 mg/kg, 2021年重金属元素含量明显高于其他年度,元素空间相关性年际变化较大。Cu、Zn、As高值区主要分布在研究区域的下游,Cd高值区主要分布在中游,Cr高值区主要分布由下游变为中游,Pb高值区主要分布由下游变为中、下游。重金属生态风险表现为Hg生态风险等级上升,Cu中等生态风险持续存在且范围扩大,Cr中等生态风险间歇性出现。  相似文献   

14.
大连沿海虾夷扇贝体内重金属含量研究与质量评价   总被引:2,自引:0,他引:2  
用微波消解对大连沿海虾夷扇贝样品进行处理,电感耦合等离子体质谱法测定虾夷扇贝不同组织中重金属Pd、Cd、Hg、Cr、Cu、Zn的含量,同时对重金属含量进行质量评价。试验结果表明,Pd、Cd、Hg、Cr、Cu、Zn在不同海域虾夷扇贝中的含量相差较大,6种重金属的平均含量分别为0.488、2.924、0.047、1.394、2.152、36.08mg/kg,即ZnCdCuCrPbHg。虾夷扇贝不同组织蓄积重金属具有明显的差异性,闭壳肌中重金属Cd、Cu的含量显著低于其他组织,Zn的含量却高于内脏团,不同组织对Cr的蓄积程度差异较小。调查发现,虾夷扇贝中重金属Cd的含量较高,尤其内脏部分远超过我国无公害水产品中有毒有害物质限量,建议食用虾夷扇贝时去除内脏团。  相似文献   

15.
张玉平  刘金金  张芬 《中国水产科学》2020,27(12):1448-1463
为综合评估上海地区池塘沉积物环境质量状况,2016-2019年对上海地区36个养殖场池塘采集沉积物样品360个,检测和分析沉积物中总氮(TN)、总磷(TP)、总有机碳(TOC)及重金属Cu、Zn、Pb、Cd、Cr、Hg和As含量。研究结果表明,池塘0~10 cm层和10~20 cm层沉积物中TN、TP、TOC及各重金属均值分布无显著差异(P>0.05),0~20 cm层沉积物(干重)中TN、TP和TOC平均含量分别为(873.37±352.45)mg/kg、(685.66±199.66)mg/kg和(6.62±3.05)mg/g,三者相关性显著。综合污染指数法和有机指数法评价结果表明,池塘沉积物中氮和有机物质的累积量较低,磷累积量相对较高,均低于其他地区高产池塘。池塘沉积物中Cr、Cd、Cu和Hg样品超标率分别为6.42%、3.21%、4.13%和1.38%,Zn、Pb和As无超标现象。地质累积指数、潜在生态危害指数法和一致性沉积物质量基准评价结果表明,上海地区池塘沉积物中重金属整体上处于清洁等级、低潜在生态危害状态,预测不会引发生物毒性效应。  相似文献   

16.
应用双箱动力学模型模拟了菲律宾蛤仔在Pb、Zn、Cu、Cd、Cr、Hg和As 7种重金属混合暴露条件下,内脏团、鳃、斧足及基部和外套膜组织对重金属的生物富集与释放实验,并通过非线性拟合得到菲律宾蛤仔各组织对7种重金属的富集速率常数k1、排出速率常数k2、生物富集系数BCF、生物半衰期B1/2、富集平衡时生物体内重金属含量CAmax等动力学参数。结果表明,1)重金属在菲律宾蛤仔不同组织器官中的富集具有选择性,理论平衡状态下,Cu、Cd、As、Pd在各组织的含量分布(CAmax):内脏团斧足及基部鳃外套膜;Cr分布规律(CAmax):内脏团鳃斧足及基部外套膜;Hg分布规律(CAmax):斧足及基部外套膜鳃内脏团;Zn分布规律(CAmax):斧足及基部鳃外套膜内脏团。2)菲律宾蛤仔对不同重金属的富集系数存在显著差异(P0.05),对Cu富集程度最高,其富集系数范围为1514.0-4818.0;其次是Cd和Hg,富集系数范围分别为104.5-975.4,255.9-447.4;As、Cr、Pb、Zn离子在菲律宾蛤仔体内富集程度较低,其富集系数均在300以内。3)菲律宾蛤仔对重金属的释放能力较差,双箱动力学模型可较好地反映混合暴露条件下菲律宾蛤仔对重金属的富集特征,但不适合对其释放特征进行描述。  相似文献   

17.
了解浙江温州地区主要入海河流重金属空间分布特征,合理评价研究区域水体重金属的潜在生态风险。在温州地区3条主要入海河流瓯江、飞云江和鳌江分析6种重金属的含量和空间分布,采用重金属污染指数法(HPI)和物种敏感性分布法(SSD)进行生态风险分析。Cu、Pb、Zn、Cd、Cr、As的浓度分别为12.46~1 830.01、2.94~372.79、19.58~435.04、0.06~0.79、14.11~192.98和1.59~63.95μg/L,平均值分别为801.68、73.80、168.61、0.26、81.06和23.53μg/L。HPI评估结果表明,O4、F2、A1和A2 4个站位重金属污染程度高,F1站位污染程度中等,O1、O2、O3和A3污染程度低;其中对水体重金属污染贡献程度较高的4种重金属分别为Cu、Pb、Cd和Cr。SSD风险评价结果表明,Cu、Zn、Cr和As在所有站位的表现均为高生态风险,Pb在O4和A2站位表现为高生态风险,说明这5种重金属对所在区域水生生物具有较高的潜在危害。2种方法从不同角度对重金属的潜在生态风险进行了评价,能有效规避单一评价方法的不足,互为补充。  相似文献   

18.
This paper compares and discusses the accumulation of eight heavy metals (Cd, Co, Cr, Cu, Pb, Fe, Mn and Zn) and total phosphorus (TP) in surface sediments from five intensive farms of tilapia Oreochromis niloticus×Oreochromis aureu, Asian seabass Lates calcarifer and white shrimp Litopenaeus vannamei (n=75). Results indicate that the sediments were significantly contaminated by Cd, Co, Cr, Cu, Pb, Fe, Mn and Zn as well as P. The mean concentrations of Cd (0.47 mg kg?1), Co (2.25 mg kg?1), Cu (31.56 mg kg?1), Pb (23.45 mg kg?1), Fe (1.15%), Mn (145.5 mg kg?1), Zn (41.5 mg kg?1) and TP (750.69 mg kg?1) in tilapia farm surface sediments were significantly lower than the levels observed in Asian seabass and white shrimp farm surface sediments, where the concentrations were, respectively, Cd – 2.69 and 2.35 mg kg?1, Co – 17.66 and 15.22 mg kg?1, Cu – 116.84 and 110.03 mg kg?1, Pb – 38.5 and 33.26 mg kg?1, Fe – 3.4% and 3.31%, Mn – 853.61 and 728.5 mg kg?1, Zn – 105.21 and 83.92 mg kg?1 and TP – 1445.63 and 1069.8 mg kg?1. The heavy metal content of the sediments follow the order: Asian sea bass>white shrimp>tilapia. Cadmium and Cu in Asian seabass and white shrimp farm sediments would pose a major potential risk. Further, the sediment is highly enriched by Fe, P, Mn and Co.  相似文献   

19.
深沪湾海水、沉积物及贝类体内重金属的含量与评价   总被引:12,自引:1,他引:12  
利用1998年5月和9月深沪湾海域环境调查资料,着重分析了深炉湾海水、表层沉积物及褶牡蛎和菲律宾蛤仔体内重金属的含量及分布,结果表明:深沪湾海水中Cu、Pb、Cd、Zn、Hg等含量均低于渔业水质标准,而表层沉积物的Pb、Zn含量大部分已超标,近岸水域海水和表层沉积物中Cu、Pb、Cd、Zn的含量明显高于湾中心水域,湾顶水域高于湾口水域。Hg的含量是湾南部水域高于北部水域。文中还根据全国海岸带污染综合调查专业组制定的海洋生物污染评价标准,对2种贝类的重金属污染程度进行评价,结果深沪湾的养殖贝类体内的重金属含量均未超标。  相似文献   

20.
根据2006-2015年4个航次对唐山附近海域共70个采样站位的表层沉积物调查资料,分析了沉积物中Hg、Cu、Pb、Cd、Cr、Zn和As 7种重金属的含量和年际变化特征,并利用超标率统计法、地累积指数法和潜在生态风险指数法对其污染状况进行了评价.结果显示,调查海域表层沉积物中重金属含量总体水平较低,除个别站位的Cu和As超过第Ⅰ类标准值外,其他调查站位的重金属含量均符合第Ⅰ类标准.2006-2015年调查海域表层沉积物中7种重金属含量的年际变化略有不同,其中,Cu、Pb、Cd和Zn4种重金属含量相对比较稳定,Hg和Cr的含量表现为先升高后降低的趋势,而As的变化趋势不明显.地累积指数法评价结果显示,7种重金属的地累积指数(Igeo)多年平均值为Hg>Cd>Pb>Cu>As>Cr>Zn;而潜在生态风险评价结果显示,7种重金属的潜在生态风险系数(Eri)多年平均值为Hg>Cd>As>Pb>Cu>Cr>Zn;两种污染评价结果一致,均显示Hg是唐山附近海域表层沉积物的主要污染因子,潜在生态风险最大.综合潜在风险指数(RJ)年际变化范围为44.26-153.18,平均值为89.92,属于低生态风险水平;RI年际变化基本表现为先升高后降低的趋势,表明近年来调查海域表层沉积物重金属的污染状况有所改善.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号