钒是地球上普遍存在的元素，是大陆地壳中含量第20位的元素，也是海水中第二常见的过渡金属。因为钒在生产和消耗方面的不断增长、多样性和正在进行的研究，许多文章和组织将钒纳入我们社会中最重要的痕量金属。同样，沿海生态系统由于其发展、产业和城市化与沿海污染高度相关，在全球范围内承受着相当大的压力。尽管如此，对沿海生态系统中的钒的研究却少得多，即使在现有的研究中，与汞、砷或镉等类似的痕量元素相比，对于钒，仅简要报告了其平均浓度。本研究选择了三种介质，即沉淀物、水、生物群，以及中国的三个关键沿海生态系统，即东海（ECS）、莱州湾（LZB）和胶州湾（JZB），在这些生态系统中，钒尚未被研究或仅作出了有关沿海生态系统中钒的重要信息的简要报告。在河流和海湾进行了四年以上的现场采样；共采集了4个岩心、284个沉淀物、357个水源地和494个生物样本，以上采样均在存在大量人口和产业发展的地区进行，这引起了人们对钒污染引起生态系统退化的关注。岩心沉淀物用于确定ECS、LZB和JZB中钒的历史浓度、变化、重大的大规模环境事件和区域地球化学背景。此外，沿海生态系统具有多种介质，例如沉淀物、水和生物群，这些介质高度相连并调节污染物的扩散、运输、迁移、积累和风险。尽管提供了大量关于生态系统污染的信息，但对研究区域内不同介质的调查和整合研究仍然有限。此外，污染物的时间、空间和季节变化是重要指标，其提供了面临人为压力的区域内的要素变化的重要信息。因此，受煤炭发电厂、石油化工、油田或港口等钒相关产业影响的沿海生态系统是研究钒对生态系统退化影响的最佳区域。河流和沿海样本强调了钒浓度与钒相关产业和其他非生物元素的关系。季节采样探讨了流域、沉淀物通量和海湾形态的时空变化及其对钒积累的影响。水生生物提供关于从水和沉淀物中摄取钒以及钒的营养级放大的信息。最后，从每种介质中，评估了钒污染、人为贡献，以及检测样本中存在的钒对沿海环境的任何离散和概率风险。主要结论如下：
（1）外海的钒浓度高于半封闭海湾，ECS、LZB和JZB的钒浓度范围分别为98.01-131.70、66.35-104.33和34.95-75.58μg g-1。LZB和ECS中的钒浓度剧烈波动，并遵循与人类活动和中国最大的两条河流——长江和黄河——的自然河道引起的沉淀物通量相似的趋势。ECS中的钒浓度每年减少0.07μg g-1，这与自1968年以来，因为丹江口水库、土壤保持工程和三峡大坝等大型项目的建立，导致的沉淀物的显著减少相关。多年来，钒的浓度与其自然水平相似，所有岩心剖面均被归类为未污染沉淀物。在LZB中，钒浓度随年波动，但受到黄河河道的影响。自1934年以来，钒浓度以每年0.15 μg g-1的速度显著增加。尽管河流中的沉淀物通量大幅减少，但核心区上部的污染水平逐渐增加，其被归类为低污染栖息地。此外，JZB中的钒浓度体现出产业和沿海发展的重大影响，主要是黄岛附属于大陆之后的影响。黄区附近的沉积岩心每年增加0.23 μg g-1，预计到2060年，将导致该地区到达较高的历史压力。有机物在很大程度上提升了钒的浓度，这是由于其在痕量金属和沉淀物基质之间的结合机制得到了自土地开垦以来逐步增加的支持。同样地，污染指数表明，JZB中的钒排放、迁移和循环在沉淀物中积累的浓度超过了自然水平。
（2）为确定钒热点和污染区域，选定地点受到了进一步研究。JZB河流中的钒浓度在各个地点之间最高，范围在35.14至134.6μg g-1之间，而LZB河流的平均值相似，范围较小，为59.41±9.70（38.11−88.19）μg g-1。两个海湾的海洋样本中的钒浓度均高于河流中的钒浓度。总体而言，钒相关产业附近的沉淀物钒浓度显著高于传统产业附近的沉淀物，其中JZB和LZB沉淀物的钒浓度分别高出19.1%（14%-26.3%）和14.9%（10.4%-21.5%）。钒在LZB的积累与细沉淀物、氧化物（例如：如Fe、Ti、Mn）和有机物呈正相关，而JZB中部分的时间变化突出了氧化物、pH和氧化还原条件对其积累的影响。钒与有机物以单、双和三齿配位形成强络合物，因为它们促进了在沉降颗粒上的吸附。地球化学归一化后，河流和海洋沉淀物中的浓度呈下降趋势。同样，根据修正的内梅罗污染指数，来自LZB的海洋样本显示出轻微污染的沉淀物。JZB、河流和海湾的钒浓度的升高被归类为轻度污染，并与人为活动（如煤炭和石化产业）相关。时间变化表明，海湾和河流沉淀物中钒浓度呈下降趋势。人类可能是导致JZB和LZB中钒积累高达46.8%和16.2%的原因。
（3）总体而言，JZB中的钒浓度（0.41-52.7 μg L-1）高于LZB（0.39-17.27 μg L-1），而JZB和LZB中的钒浓度都高于世界范围内的大多数研究。钒相关产业对河流中金属浓度有显著影响（p<0.05），其中JZB和LZB河中金属浓度分别增加37.2%（30.5-77.4%）和74.5%（45%-89.9%）。此外，钒表现出明显的季节变化。由于钒对氧化物的强吸附能力，Fe和DOC影响了钒的时间增长。河流样本与DOC正相关，因此抑制了钒在例如铁氧化物等物质上的吸附，从而影响河流中钒的迁移率和增量。夏季，海湾和河流中DOC增加，其为钒的季节性增加的重要因素。冬季，DOC为各季节最低；尽管如此，钒迁移率的增加也有关联。冬季pH值最高；因此，结合不寻常的降雨模式和其他非生物因素（如温度）的变化，尽管DOC减少，钒浓度仍增加。同样，由于淡水输入量减少，后季风期对JZB的钒浓度有很大影响，冬季河流和海湾中的钒浓度明显较高。最后，在2021年和2022年间的样本中，JZB, LZB和LZB沿岸河流靠近钒相关产业的海岸和河流控制点中的沉淀物也呈现下降趋势。
（4）海洋生物体中的钒浓度因分类物种而异，软体动物中的钒浓度较高，其次是甲壳类动物和鱼类。从LZB采集的微生物中也定量了显著较高的浓度。无脊椎动物体内浓度较高与消化过程有关，无脊椎动物有两种主要消化过程，细胞外和细胞内消化，而鱼类只有第一种过程。休闲垂钓者在海岸附近捕获的鱼中的钒浓度比从海湾对面的渔船和市场获取的鱼高1.6到2.5倍。多年来钒浓度显著增加，预计2021年将达到最高值。使用生物浓缩因子（BCFs）在生物、沉淀物、水体之间的迁移研究得出，在所调查的98个物种中，其迁移范围在4.8～443.9之间。这些值与钒估算的BCF相似，因此表明浓度可能已累积至最高水平。最后，营养级放大因子表明，钒在两个海湾和分类群中沿着食物链被稀释。
（5）由于大量人口依赖这些生态系统，生态和人类健康存在风险是必然的。物种敏感性分布表明，影响5%种群的浓度为1.12（0.05–22.7）μg L-1。除了研究区域估计的浓度外，本研究还收集了全球沿海沉淀物、水和鱼类中钒的浓度。因此，考虑到钒浓度的最低浓度，JZB、LZB、欧洲、非洲、美洲、亚洲和大洋洲中的2.9%、3.1%、3.1%、12.4%、10.9%、14.1%和0.6%的物种可能分别受到水生生态系统中钒浓度的影响。两个研究区域的生态风险都很高，复原力有限的淡水和海洋物种可能面临中高风险，使用概率方法得出的发生率为65-93%，使用确定性评估得出的发生率为52-97%。相反，通过多重单独金属风险分析，沉淀物中的钒表明钒对我们研究地区和世界的水生生物没有风险。最后，尽管某些浓度高于中国制定的饮用水指南中规定的浓度，但根据两种方法来看，钒对人口的风险较低，甚至无风险。健康风险表明，鱼类和无脊椎动物的钒浓度对LZB、JZB和不同大陆的消费者无风险。总体而言，沉淀物样本和水样呈下降趋势，山东省煤炭使用量呈显著下降趋势，直接和间接促成了这些变化。本研究为评估海湾和面临类似特征和行业的类似生态系统中的钒状况、污染和风险提供了指导。同样，那些依赖石油或煤炭的地区也是钒积累和风险的潜在热点地区。其中一些地区尚未被研究，因此需要填补生态治理方面的空白。

Vanadium is a ubiquitous element on earth, the 20th most abundant element on the continental crust, and the second most common transition metal in seawater. Numerous articles and organizations have classified vanadium among the most crucial trance metals of our society owing to its constant increases in production and consumption, versatility, and ongoing research. Likewise, coastal ecosystems receive significant levels of pressure worldwide due to their development, industries, and urbanization being highly linked with coastal pollution. Nonetheless, vanadium in coastal ecosystems has been under significantly less investigation, and if studied, only the average concentrations have been briefly reported compared to similar trance elements like mercury, arsenic, or cadmium. This research selected three media, e.g., sediments, water, biota, and three critical coastal ecosystems of China, the East China Sea (ECS), Laizhou bay (LZB), and Jiaozhou bay (JZB), where vanadium has not been investigated or has been briefly reported to provide valuable information on vanadium in coastal ecosystems. The field sampling was conducted in rivers and bays over four years; a total of 4 cores, 284 sediments and 357 water sites, and 494 biological samples were collected where substantial human populations and industrial development exist that raise concern over ecosystem degradation by vanadium contamination. Core sediments were used to determine the historical concentrations, changes, significant large-scale environmental events, and regional geochemical background of vanadium in the ECS, LZB, and JZB. Furthermore, coastal ecosystems have multiple media, e.g., sediment, water, and biota, which are highly connected and regulate the diffusion, transport, migration, accumulation, and risks of pollutants. Studies investigating and integrating different media within a study area are limited despite providing substantial information on ecosystem pollution. Moreover, pollutants' temporal, spatial, and seasonal changes are essential indicators that provide crucial information regarding the changes of an element in areas that are facing anthropogenic pressure. Thus, coastal ecosystems impacted by vanadium-related industries, such as coal power plants, petrochemical, oil fields, or ports, dominant along the coast are optimal areas to study their impact on ecosystem degradation. Rivers and coastal samples highlighted the relationships of vanadium concentrations in connection with vanadium-related industries and other abiotic elements. Seasonal sampling explored the spatiotemporal variations and the impacts of the watershed, sediment flux, and bay morphology on vanadium accumulation. Aquatic organisms provide information about the uptake of vanadium from water and sediments and the trophic magnification of vanadium. Last, from each media, vanadium pollution, anthropogenic contributions, and any discrete and probabilistic risks to coastal environments derived from the vanadium present in the examined samples were evaluated. The main conclusions are as follows:
(1) Vanadium concentrations were higher in the open sea than in a semi-enclosed bay and ranged approximately 98.01-131.70, 66.35-104.33, and 34.95-75.58 μg g-1 in ECS, LZB, and JZB, respectively. Vanadium concentrations in LZB and the ECS showed drastic fluctuations and followed similar trends to sediment fluxes caused by anthropogenic activities and the natural courses of the two largest rivers in China, the Yangtze and Yellow Rivers. The ECS shows a reduction of vanadium concentrations by 0.07 μg g-1 per year, which is correlated with the significant decrease in sediments since 1968, with the establishment of large projects like the Danjiangkou Reservoir, soil conservation works, and the Three Gorges Dan. Over the years, vanadium showed concentrations similar to its natural levels, and all the core sections were classified as unpolluted sediments. At LZB, vanadium concentrations fluctuated over the years but were influenced by the Yellow River course. Since 1934, vanadium concentrations have increased significantly at an annual rate of 0.15 μg g-1. Despite a substantial reduction in sediment flux in the river, pollution levels have gradually increased in the upper sections of the core were classified as low-contaminated habitats. Moreover, vanadium concentrations in JZB illustrate the significant impacts of industries and coastal development, principally those after the attachment of Huang Island to the mainland. The sediment core near the Huang district denoted an annual increase of 0.23 μg g-1 of vanadium and is expected to match the site with higher historical pressure by 2060. Organic matter (OM) is significantly driving vanadium concentrations owing to its binding mechanisms between trace metals and the sediment matrix supported by step increases since the land reclamation. Likewise, pollution indices suggested that vanadium emission, migration, and circulation in JZB accumulate in sediments at concentrations beyond the natural levels.
(2) Selected sites were further investigated to identify those vanadium hotspots and pollution areas. Vanadium in JZB rivers had the highest values across sites and ranged between 35.14 and 134.6 μg g-1, while LZB rivers showed a similar mean and a smaller range, 59.41 ± 9.70 (38.11−88.19) μg g-1. Vanadium concentrations in marine samples were higher than those in rivers in both bays. Overall, sediments near vanadium-related industries have significantly higher vanadium concentrations than those near traditional industries, with 19.1% (14%-26.3%) and 14.9% (10.4%-21.5%) higher concentrations of vanadium in sediments of JZB and LZB, respectively. Vanadium accumulation at LZB is positively correlated with fine sediment, oxides (e.g., Fe, Ti, Mn), and OM, while temporal changes in parts of JZB highlight the impacts of oxides, pH, and redox conditions on its accumulation. Vanadium forms strong complexes with OM in a mono-, bi-, and tridentate coordination as they promote the adsorption onto settling particles. After geochemical normalization, the concentrations in rivers and marine sediments show a decreasing trend. Likewise, marine samples from LZB showed slightly polluted sediments under the Modified Nemerow pollution index. The elevated concentrations of vanadium in JZB, rivers and bay, were classified as slightly polluted and correlated with anthropogenic activities, such as coal and petrochemical industries. Temporal changes indicated that vanadium in sediments from the bays and rivers is decreasing. Humans could be responsible for up to 46.8% and 16.2% of the vanadium accumulation in JZB and LZB.
(3) Overall, vanadium concentrations were higher in JZB (0.41-52.7 μg L-1) than in LZB (0.39-17.27 μg L-1), with concentrations higher than the majority of the worldwide studies. Vanadium-related industries significantly impacted (p<0.05) the metal concentrations in the rivers, with 37.2% (30.5-77.4%) and 74.5% (45%-89.9%) greater concentrations in JZB and LZB rivers. In addition, vanadium exhibited significant seasonal variation. Temporal increases in vanadium were influenced by Fe and DOC owing to the strong adsorption capacity of vanadium for oxides. Riverine samples were positively associated with DOC, hence inhibiting vanadium from adsorption onto, for example, Fe oxides and thus influencing the mobility and the vanadium increment across rivers. During summer, DOC increased in the bays and rivers, thus being an essential factor toward the seasonal increases of vanadium. During winter, DOC was the lowest across seasons; nonetheless, increments in vanadium mobility have also been associated. pH in winter was the highest; thus, in conjunction with the unusual rainfall patterns and other changes in abiotic factors, e.g., temperature, vanadium concentrations increased despite the reduction of DOC. Likewise, impacted by smaller freshwater inputs, the post-monsoon period substantially affected vanadium concentrations in JZB, and vanadium in the rivers and bays was significantly higher during the winter. Last, the coast and riverine control sites of JZB and LZB and LZB rivers near vanadium-related industries as with sediments also showed a deceasing trend between the 2021 and 2022 samples.
(4) Vanadium concentrations in marine organisms are variable between taxonomic species, with higher concentrations in mollusks followed by crustaceans and fishes. Significantly higher concentrations were also quantified in the organisms collected from LZB. Higher concentrations in invertebrates are linked with the digestion processes, invertebrates have two major processes, extracellular and intracellular digestion, while fishes only have the first. Fishes collected by recreational anglers near the coast had 1.6 up to 2.5 times higher concentrations than those obtained from fishing boats and markets across the bays. There was a significant increase in vanadium concentration over the years, with the highest values estimated in 2021. The transfer between organisms and sediments and water using bioconcentration factors (BCFs) indicates that it ranges between 4.8 and 443.9 among the 98 species investigated. These values are similar to the BCF estimated by vanadium, thus suggesting that concentrations could have accumulated at their highest level. Last, the trophic magnification factors indicated that vanadium is diluted along the food chain in both bays and among taxonomic groups.
(5) The ecological and human health risks are necessary owing to the significant population dependent on these ecosystems. The species sensitivity distribution indicated that the concentration affecting five percent of the population is 1.12 (0.05–22.7) μg L-1. This study also collected the concentrations in worldwide coastal sediments, water, and fish, in addition to the concentrations estimated in our study areas. Therefore, considering the minimum concentration of vanadium concentrations, 2.9, 3.1, 3.1, 12.4, 10.9, 14.1, and 0.6 of the species in JZB, LZB, Europe, Africa, the Americas, Asia, and Oceania could be affected by vanadium concentrations in aquatic ecosystems, respectively. High ecological risks were estimated in both study areas, freshwater and marine species with limited resilience are likely to face medium to high risks, with an incidence of 65-93% using the probabilistic method and 52-97% using the deterministic assessment. Conversely, vanadium in sediments, as multiple individual metal risk analyses, indicated that vanadium represents null risks to aquatic organisms in our study areas and the world. Last, despite some concentrations being higher than that indicated in the drinking water guidelines established by China, vanadium presents low to null risks to the population as per both approaches. The health risks exhibited that vanadium concentration in fish and invertebrates represents null risks to consumers in LZB, JZB, and different continents. Overall, sediment and water samples show a decreasing trend, in the Shandong province coal use has shown a significant decreasing trend that directly and indirectly contribute to these changes. The study serves as a guideline for assessing the status, pollution, and risks of vanadium in bays and similar ecosystems facing similar characteristics and industries. Likewise, those areas dependent on oil or coal are potential hotspots of vanadium accumulation and risks. Several of these areas have not been investigated, thus a gap to fill toward ecological governance.