Dipartimento di Scienze Della Vita e Dell'Ambiente, Università Politecnica Delle Marche, Via Brecce Bianche, 60131, Ancona, Italy.
Dipartimento di Scienze e Ingegneria Della Materia, Dell'Ambiente Ed Urbanistica, Università Politecnica Delle Marche, Via Brecce Bianche, 60131, Ancona, Italy.
Mar Environ Res. 2020 Apr;156:104907. doi: 10.1016/j.marenvres.2020.104907. Epub 2020 Feb 5.
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.
自几十年前以来，人们已经记录了污染物对海洋生物的影响，但需要进一步研究底栖生物群落对混合物的长期反应和恢复速度，这些混合物是在工业活动停止数年之后的污染物。Bagnoli-Coroglio 湾（那不勒斯湾，第勒尼安海）是由于 90 年代初停止工业活动而导致历史上受到污染的典型沿海地区。在本研究中，我们对沿五个水深横切的中型生物（和线虫）组合的分布进行了精细的空间尺度分析，这些横切位于与沉积物中存在的多环芳烃和重金属浓度相关的离历史污染源增加的距离。中型生物的丰度和生物量沿横切变化很大，但与污染源的距离无关。即使污染水平预计会引起重大的有害生物后果，中型生物的丰度和生物量与世界范围内未受污染的沿海底栖地区报告的相似。相反，就中型生物分类丰富度而言，生物多样性通常较低（在所调查的 15 个站点中的 12 个中，范围为 5-8 个分类）。这是由于缺乏通常在底栖沿海生态系统中遇到的敏感类群，例如介形类动物、腹毛类动物和缓步类动物，从而反映了调查区域的整体较差/中等环境质量。线虫（结构和功能）多样性也较低，特别是在污染水平较高的站点。同时，线虫物种组成在各站点之间没有明显变化，表明污染物的广泛影响能够减少整个研究区域组合内的变异性（即周转率多样性）。总体而言，我们的研究结果表明，即使在停止排放污染物几十年后，底栖生物多样性在中型生物分类和线虫物种方面都受到了影响。这些发现强烈呼吁减少海洋生态系统中慢性污染的来源，并为更好地了解历史上受到污染的海洋环境的生态恢复提供了新的见解。
