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以某滨海核电厂为例,分析确定58 Co、60Co、90Sr、134 Cs、137 Cs和110m Ag等放射性核素为该核电厂低放射性废水中的主要海洋环境影响评价因子.根据国际原子能机构推荐的评估模式预测了上述放射性核素排海后对电厂排放口海域环境(海水水质和沉积物质量)的影响,预测结果表明该核电厂低放射性废水正常排放后,排放口附近海域海水中的58 Co、60Co、134Cs、1 10m Ag比活度低于放射性核素比活度背景值检测限2～3个数量级;90Sr低于背景值4个数量级;137Cs略高于背景值,对周围海水环境未造成放射性污染.但58 Co、60Co、134Cs、137Cs、110m Ag在排放口近岸海域沉积物中的沉积量分别比背景值检测限高2～5个数量级,其中60Co和110m Ag沉积量最大;90Sr沉积量低于放射性背景值2个数量级.最后提出可以从生物辐射评价和核素的迁移转化规律、联合效应(综合考虑温排水、低放射性废水和余氯)和选取合适的指示生物3个方面进行跟进研究的建议,以便更完善和全面地评价核电厂低放射性废水对排放口附近海域环境的影响. 相似文献
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通过跟踪监测华电青岛发电有限公司脱硫海水排放口附近海域的水质、表层沉积物质量和海洋生物群落结构,初步探讨了脱硫海水排放对海泊河口及附近海域生态环境的影响。结果表明:(1)脱硫海水特征污染物排放对排水口下游水域会造成一定不利影响,主要表现在pH值和DO的明显降低以及水温的明显升高,影响范围局限于排水口下游400m范围内的河口段;(2)脱硫海水排放不会明显增加排水口下游COD、N、P的污染负荷;(3)脱硫海水排放未显著增加附近海域重金属的综合潜在生态危害程度,重金属的潜在污染风险较小;(4)调查海域冬、夏两季生物多样性较高,群落结构较稳定,脱硫海水排放未对生物群落结构和生物多样性造成明显的不利影响。 相似文献
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南澳岛是广东南澳县的主岛, 周边海域的环境保护被置于当地社会经济发展的重要位置。为此, 2004年 5月、7月选择以水产养殖为主的后江湾和白沙湾及以旅游为主的青澳湾作为研究对象, 对南澳岛海域重金属的 含量、分布、富集及污染状况进行了调查与评价。结果表明该海域重金属元素的平均含量为Cd: 0.19mg.kg-1, Cr: 26.86mg.kg-1, Cu: 20.71mg.kg-1, Ni: 22.78mg.kg-1, Pb: 35.67mg.kg-1, Zn: 79.48mg.kg-1, 低于近岸经济发达海域, 但高于受人类活动影响较小的外海; 在分布特征上表现为湾口高于湾内, 养殖区高于非养殖区的总趋势, 但在各海湾之间重金属含量并无显著差异, 表明南澳岛海域重金属主要来源于地表径流输入。该海域以城市污水中代表元素Cu (Cf = 2.75), Pb (Cf = 2.27)富集为主; 以海洋沉积物质量标准、沉积物质量基准和美国太平洋沿岸基线值评价, 南澳岛海域环境质量均处于健康状态, 但其潜在污染效应仍值得关注。 相似文献
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本文采用欧盟ERICA框架下评估电离辐射生态风险的ERICA综合法,选用ERICA工具数据库中的参数数据,计算了我国大亚湾等核电站液态放射性流出物中主要的18种放射性核素的环境安全浓度限值。当核电站排水口附近海域中放射性核素浓度低于推荐的环境安全浓度限值时,放射性核素造成的辐射风险被认为是在海洋生态环境所能承受的范围之内。 相似文献
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采用衍生化处理和气相色谱-质谱联用分析方法, 测定了珠江口及其以东近海海域表层海水中的三氟乙酸(Trifluoroacetic acid, TFA)含量。珠江口及其以东近岸的红海湾和大亚湾海区TFA浓度范围分别为113—170ng.L–1和202—336ng.L–1。红海湾内海水中TFA的平均水平(279ng.L–1)明显高于外海海水(210ng.L–1), 说明港湾内或其周边地区可能有TFA的点源输入。此外, 外海海水中TFA平均浓度比珠江口高69.1ng.L–1, 表明这种亲水性强、稳定性高的化合物除了已知的人为来源外, 可能还存在未知的人为源或自然源, 使得海洋作为其最终的汇浓度不断累积。 相似文献
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近年来海洋生态灾害频发,大量漂浮藻类聚集在海面和近岸海域,给沿岸城市的经济活动和生态健康带来了严重危害。本研究利用HY-1C、GF-1和HJ-1A/1B卫星遥感影像对南黄海海域2016–2020年4–6月份的马尾藻进行了信息提取和生长阶段的划分,并通过MODIS海温数据、光合有效辐射数据和海面风场数据来探究环境因子对马尾藻时空分布的影响。结果表明:（1）从时间上看马尾藻集中在每年的4–6月份暴发,2017年马尾藻的影响范围最大,其余年份较小;从空间上看马尾藻最早在长江入海口东北部远海被监测到,在35°～36°N附近海域消失;（2）从生长速率上看,马尾藻的生长阶段可以划分为“发展–暴发–消亡”3个阶段;（3）在不同的生长阶段,海水温度和光合有效辐射对马尾藻具有不同程度的影响,较高的海表温度和光合有效辐射导致2017年面积高于往年;在东南风的作用下,马尾藻呈从东南向西北漂移的趋势,这说明了马尾藻的时空特征受到多种环境因子的影响。 相似文献
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为了解海南昌江核电厂周围海域放射性水平,两次海域放射性调查分别于2009年和2017年进行。两次调查的调查项目、范围、频次、站位、要素等均依据相关标准规范制定。调查中的采样、预处理和放化分析方法也参照了当时最新的标准规范要求。通过对调查结果的对比分析显示,两次调查中海水、沉积物、海洋生物的绝大部分测量结果基本处于同一水平,可认为海南昌江核电厂1、2号机组的运行未对周围海域环境放射性水平产生明显影响,建议在后续监测工作中进一步关注90 Sr。 相似文献
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根据2021年威海西北部污水排海口附近海域水质监测结果,对海水水质现状进行了评价;结合2007年调查水质监测结果和2017—2021年连续监测数据,分析了污水排放前后和近年附近海域海水水质的变化趋势;采用Mike 3三维潮流和污染物扩散耦合模型,预测了污水排放量增加(提量)、污染物排放标准提高(提标)后排放污水中COD、无机氮、活性磷酸盐对海洋环境的影响范围和程度。结果表明：研究区海水水质较2007年略有下降,但排水口处及外侧海域大部分站位符合海水水质二类标准,海水水质状况相对较好,威海污水处理厂多年污水离岸深水达标排放对区域海洋环境的影响较小。污水处理厂提量、提标改造后,特征因子中仅无机氮扩散范围略超原污水排放混合区用海范围,不会对研究区水质环境造成明显影响。 相似文献
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本研究综述了国际上海洋环境辐射质量评价方面的研究进展,结合我国海洋管理的实际需求,提出将海洋环境辐射质量分为4个级别(1~4级分别表示环境放射性水平处于本底范围、超出本底范围但无危害、所致公众辐射剂量超出限值和所致海洋生物辐射剂量超出限值),并提出了各级导出活度浓度限值的确定原则。其中,确定第1级导出活度浓度限值的依据为我国的放射性本底调查数据,采用统计分析的方法,取绝大多数本底值的上限值,作为分级阈值。确定第2级导出活度浓度限值的依据为公众辐射剂量限值、鱼类对不同核素的浓集系数、不同核素的剂量转换因子、海产品消费量等参数,原则是确保在正常摄入海产品的情况下,对公众造成的辐射剂量不超过国家标准规定的年剂量限值。确定第3级导出活度浓度限值的依据为国际上有关海洋生物发生辐射效应阈值的研究成果,原则是保护海洋生物种群不受辐射伤害。最后,本研究将根据各级的分级阈值与现行国家标准限值进行比较。本研究成果有助于国内工作在一线的海洋监测人员对常规监测数据进行评价,亦为海洋管理决策提供技术支持和参考依据。 相似文献
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Microbial products based on the entomopathogenic bacterium Bacillus thuringiensis (Bt) are among the most common biopesticides used worldwide to suppress insect pests in forests, horticulture and agricultural crops. Some of the effects of commercial Bt have been recorded for terrestrial and freshwater non-target organisms but little research is available on marine fauna. Nevertheless, due to the contiguity of agro-ecosystems and coastal habitats, marine fauna may be highly influenced by this control method. We studied the effect of a commercial Bt product on the physiological and ecological responses and the energy budget of two of the most frequent marine intertidal bivalves in the Mediterranean, the native Mytilaster minimus and the invasive Brachidontes pharaonis. To test the effects experimentally, we simulated the worst scenarios possible using the average dose applied to fields and a hypothetical accumulation dose. The results showed the feeding rates of both species were affected detrimentally by the different experimental conditions; higher concentrations led to higher respiration rates, however neither species showed any significant difference in excretion rates. The biopesticide had a significant effect on the energy budget, the values decreasing with doses. In addition, it led to high mortality for the worst treatments and, in both species, induced significantly higher cardiac activity than in the controls. These results indicate a measurable effect of Bt commercial products on marine organisms, and great attention should be paid to biopesticides composed by entomopathogenic bacteria and addictive compounds. In addition, the results highlight the urgent need to study not only the effects of anthropogenic pressures on target organisms but also to extend our view to other ecosystems not expected to be influenced. Gaining data at the organismal level should help increase the sustainability of pest control and reduce the consequences of side-effects. 相似文献
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Colombia has coasts on both the Atlantic and Pacific Oceans, but its marine fisheries are limited by the relatively small size of commercially important stocks. However, diverse fishery resources have traditionally been exploited by coastal communities, and industrial fisheries have grown in recent years with the intensification of tuna fishing in both oceans. The management of Colombia's fisheries has been hampered by frequent administrative changes, which has notably led to the disappearance of a part of the official landings data. We estimated total fisheries removals (reported plus discards and unreported catches) in the Colombian Atlantic and Pacific Oceans for the period 1950–2006. We used secondary sources of information to estimate missing data, and we estimated subsistence fishing and the unreported by-catches of the shrimp and tuna fisheries. We used available information on seafood prices to estimate the relative economic impact (gross revenues) of the small-scale and industrial sectors for the period 2000–2006. Our results suggest that for the period 1950–2006, the Colombian marine fisheries catches may have been almost twice the landings reported by FAO on behalf of the country (2.8 times higher in the Atlantic; 1.3 times higher in the Pacific). Although the total gross revenues of industrial fisheries were higher than those of the small-scale sector, the latter commanded higher gross revenues in the Atlantic in 2006. 相似文献
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海洋微塑料是全球共同面对的环境问题和挑战,然而目前海洋微塑料从源到汇的输运和沉积过程及影响机制尚不明确。已有研究发现微塑料颗粒的垂向沉降过程受到海洋雪等水体悬浮物质的影响,但是目前相关研究只局限于定性的观察分析。在实验室中模拟含有海洋雪的近岸水体环境,使细颗粒微塑料(PS微球、PVC颗粒)与海洋雪产生碰撞、聚集,观测微塑料或微塑料-海洋雪聚集体的沉降过程。研究结果表明,水体中含有海洋雪时,一方面海洋雪会促进微塑料颗粒自身的聚集,形成更大的聚集体;另一方面由于海洋雪包裹微塑料形成松散的聚集体,导致平均沉速减小。50 μm以下的微塑料其沉降过程受海洋雪的影响较大,平均沉速减小35%以上;微塑料密度越大,受海洋雪的影响越小,平均沉速减小10%以下。沉降速率的减缓,意味着微塑料在水柱中的停留时间增加,处于不同深度的水生生物可能有更多时间和概率与微塑料接触,增加了鱼类等水生生物摄入微塑料的风险。 相似文献
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The ventilation of burrows by tube-dwelling benthos is understood to be important in determining rates of exchange of solutes between the sediment and overlying water. However, few models have attempted to link the burrow ventilation behavior of tube-dwelling organisms with their geochemical consequences. The classic cylinder model of bioirrigation in muddy sediments (Aller, R.C., 1980. Quantifying solute distributions in the bioturbated zone of marine sediments by defining an average microenvironment. Geochimica et Cosmochimica Acta 44, 1955–1965) links pore-water processes and burrow sizes and distributions in the sediment by assuming that burrows are fully flushed. The equivalence between the cylinder model and the more commonly used one-dimensional non-local exchange model depends upon this assumption. However, this assumption has seldom been tested in the field. We have extended the cylinder model of bioirrigation to include burrow ventilation activities of organisms. Burrow ventilation is modeled as a simple non-local exchange of burrow water with overlying water. Model simulations indicate that burrow ventilation has a large effect on vertical profiles and fluxes of solute tracers. We collected data on burrow geometry in the field by CT-scanning freshly collected sediment cores. At the same study sites, we measured activity profiles of 222Rn, a naturally occurring radionuclide tracer of pore-water transport. With model geometry independently constrained, we tested the model by comparing our model-predicted profiles with measured profiles. Our results demonstrate that burrows in the field are not fully flushed. Our estimated burrow ventilation rates compare favorably with previous laboratory measurements. The inclusion of realistic burrow ventilation in this pore-water transport model strongly affects modeled solute profiles and fluxes. We demonstrate how model parameters can be determined from field samples and present a model that more realistically simulates pore-water transport processes in muddy sediments. 相似文献
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The area of Arctic sea ice has dramatically decreased, and the length of the open water season has increased;these patterns have been observed by satellite remote sensing since the 1970 s. In this paper, we calculate the net primary productivity(NPP, calculated by carbon) from 2003 to 2016 based on sea ice concentration products,chlorophyll a(Chl a) concentration, photosynthetically active radiation(PAR), sea surface temperature(SST), and sunshine duration data. We then analyse the spatiotemporal changes in the Chl a concentration and NPP and further investigate the relations among NPP, the open water area, and the length of the open water season. The results indicate that(1) the Chl a concentration increased by 0.025 mg/m~3 per year;(2) the NPP increased by 4.29 mg/(m~2·d) per year, reaching a maximum of 525.74 mg/(m~2·d) in 2016; and(3) the Arctic open water area increased by 57.23×10~3 km~2/a, with a growth rate of 1.53 d/a for the length of the open water season. The annual NPP was significantly positively related to the open water area, the length of the open water season and the SST.The daily NPP was also found to have a lag correlation with the open water area, with a lag time of two months.With global warming, NPP has maintained an increasing trend, with the most significant increase occurring in the Kara Sea. In summary, this study provides a macroscopic understanding of the distribution of phytoplankton in the Arctic, which is valuable information for the evaluation and management of marine ecological environments. 相似文献
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The implications of Arctic sea ice decline on shipping 总被引：1，自引：0，他引：1
Although a ‘blue’ Arctic Ocean is predicted in the summertime to occur from the middle of this century, current rates of warming indicate an earlier realization. Also, routes along the coast of Siberia will be navigable much earlier. However, before the Arctic routes can reliably be used on a large scale for transit by shipping along its passages, more investments are required on infrastructure and the provision of marine services to ensure the safe and secure transit of shipping with minimal environmental impact. 相似文献
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Yvan Bettarel Robert Arfi Thierry Bouvier Marc Bouvy Enora Briand Jonathan Colombet Daniel Corbin Télesphore Sime-Ngando 《Estuarine, Coastal and Shelf Science》2008
The study of lysogeny in aquatic systems is an often overlooked aspect of microbial ecology, especially in tropical environments. Herein, the fraction of lysogenized cells (FLC) was detected in the surface waters of 20 coastal stations distributed from the eutrophicated shoreline to seaward waters of Hann Bay (Senegal). Concurrently, viral lytic infection rates were extrapolated from the frequency of visibly infected bacterial cells (FVIC), as determined from transmission electron microscopy observations. The experimental induction of prophage was observed in less than 3% of indigenous marine bacteria, suggesting that lysogenic stages of infection are rare in Hann Bay. Similarly, only 0.5–4.7% of bacteria showed visible signs of lytic infection. However, the positive correlation between the fraction of lysogenic and lytic cells (r = 0.67, p < 0.05, n = 20) may actually indicate that the coexistence of both lifestyles may be due to the massive and rapid induction of lysogens, potentially from the high levels of local UV radiation. Overall, we suggest that the determination of FVIC and FLC to examine the predominance of one type of cycle versus the other may be a source of misinterpretation in some particular aquatic environments. 相似文献