The effects of contaminants on marine organisms have been documented since decades, but the long-term responses and recovery rates of benthic communities to mixtures of contaminants, several years after the cessation of industrial activities, need to be further investigated. Bagnoli-Coroglio Bay (Gulf of Naples, Tyrrhenian Sea) is a typical example of historically contaminated coastal area due to industrial activities stopped at the beginning of nineties. In the present study we carried out a fine spatial scale analysis of the distribution of meiofaunal (and nematodes) assemblages along five bathymetric transects located at increasing distance from the historical source of contamination in relation with the polycyclic aromatic hydrocarbon and heavy metal concentrations present in the sediment. Meiofaunal abundance and biomass changed widely along transects but independent from the distance from the source of contamination. Even when the contamination levels were expected to induce significant detrimental biological consequences, meiofaunal abundance and biomass were similar to those reported in unpolluted benthic coastal areas worldwide. Conversely, biodiversity in terms of meiofaunal taxa richness was generally low (range: 5-8 taxa in 12 of the overall 15 stations investigated). This was explained by the lack of sensitive groups such as ostracods, gastrotrichs and tardigrades commonly encountered in benthic coastal ecosystems, thus reflecting an overall poor/moderate environmental quality of the investigated area. Nematode (structural and functional) diversity was also low, particularly at stations characterized by higher contamination levels. At the same time, nematode species composition did not change significantly among stations suggesting a widespread effect of contaminants able to reduce the variability (i.e., turnover diversity) within the assemblages of the whole study area. Overall, our results indicate that even decades after the cessation of contaminant emissions, benthic biodiversity was affected in terms of both meiofaunal taxa and nematode species. These findings strongly reinforce the call for reducing sources of chronic pollution in marine ecosystems and provide new insights for a better understanding of the ecological recovery of historically contaminated marine environments.

中文翻译：

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历史污染对动植物组合的影响：以巴尼奥利-科罗格里奥湾（第勒尼安海南部）为例。

几十年来，已经记录了污染物对海洋生物的影响，但是，在工业活动停止后的几年中，底栖生物群落对污染物混合物的长期响应和回收率需要进一步研究。Bagnoli-Coroglio湾（第勒尼安海那不勒斯海湾）是由于90年代初停止的工业活动而受到历史污染的沿海地区的典型例子。在本研究中，我们对沿距距历史污染源距离越来越远的五个等深线样剖面中的镰刀菌（和线虫）组合的分布进行了精细的空间尺度分析，并与其中多环芳烃和重金属的浓度有关。沉淀。珊瑚的丰度和生物量沿样带变化很大，但与污染源的距离无关。即使预期污染水平会导致严重的生物学有害后果，其藻类的丰度和生物量也与全球未受污染的底栖沿海地区报道的相似。相反，就牛唇类群丰富度而言，生物多样性普遍较低（范围：在所调查的全部15个站中，有12个站中有5-8个类群）。造成这种现象的原因是，在底栖沿海生态系统中普遍缺少敏感的类群，例如类，胃类动物和缓坡动物，因此反映出所调查地区的总体环境质量较差/中等。线虫（结构和功能）的多样性也很低，特别是在污染水平较高的车站。同时，线虫种类的组成在站之间没有显着变化，表明污染物的广泛影响能够降低整个研究区域集合内的变异性（即周转多样性）。总体而言，我们的研究结果表明，即使污染物排放停止了几十年，底栖生物多样性也受到了动植物种类和线虫物种的影响。这些发现强烈地呼吁减少海洋生态系统中慢性污染源的呼吁，并为更好地了解历史上受污染的海洋环境的生态恢复提供新的见解。线虫的种类组成在站之间没有显着变化，表明污染物的广泛影响能够降低整个研究区域集合中的变异性（即周转多样性）。总体而言，我们的研究结果表明，即使污染物排放停止了几十年，底栖生物多样性也受到了动植物种类和线虫物种的影响。这些发现强烈地呼吁减少海洋生态系统中慢性污染源的呼吁，并为更好地了解历史上受污染的海洋环境的生态恢复提供新的见解。线虫的种类组成在站之间没有显着变化，表明污染物的广泛影响能够降低整个研究区域集合中的变异性（即周转多样性）。总体而言，我们的研究结果表明，即使污染物排放停止了几十年，底栖生物多样性也受到了动植物种类和线虫物种的影响。这些发现强烈地呼吁减少海洋生态系统中慢性污染源的呼吁，并为更好地了解历史上受污染的海洋环境的生态恢复提供新的见解。我们的研究结果表明，即使污染物排放停止了几十年，底栖生物多样性也受到了藻类和线虫种类的影响。这些发现强烈地呼吁减少海洋生态系统中慢性污染源的呼吁，并为更好地了解历史上受污染的海洋环境的生态恢复提供新的见解。我们的研究结果表明，即使污染物排放停止了几十年，底栖生物多样性也受到了藻类和线虫种类的影响。这些发现强烈地呼吁减少海洋生态系统中慢性污染源的呼吁，并为更好地了解历史上受污染的海洋环境的生态恢复提供新的见解。