Milan Massimo, Bernardini Ilaria, Bertolini Camilla, Dalla Rovere Giulia, Manuzzi Alice, Pastres Roberto, Peruzza Luca, Smits Morgan, Fabrello Jacopo, Breggion Cristina, Sambo Andrea, Boffo Luciano, Gallocchio Loretta, Carrer Claudio, Sorrentino Francesco, Bettiol Cinzia, Lodi Giulia Carolina, Semenzin Elena, Varagnolo Maurizio, Matozzo Valerio, Bargelloni Luca, Patarnello Tomaso
Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell'Università 16, Agripolis, 35020 Legnaro, PD, Italy.
Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell'Università 16, Agripolis, 35020 Legnaro, PD, Italy.
Sci Total Environ. 2023 Mar 10;863:160796. doi: 10.1016/j.scitotenv.2022.160796. Epub 2022 Dec 14.
In recent years recurrent bivalve mass mortalities considerably increased around the world, causing the collapse of natural and farmed populations. Venice Lagoon has historically represented one of the major production areas of the Manila clam Ruditapes philippinarum in Europe. However, in the last 20 years a 75 % decrease in the annual production has been experienced. While climate change and anthropogenic interventions may have played a key role in natural and farmed stocks reductions, no studies investigated at multiple levels the environmental stressors affecting farmed Manila clam to date. In this work we carried out a long-term monitoring campaign on Manila clam reared in four farming sites located at different distances from the southern Venice Lagoon inlet, integrating (meta)genomic approaches (i.e. RNA-seq; microbiota characterization), biometric measurements and chemical-physical parameters. Our study allowed to characterize the molecular mechanisms adopted by this species to cope with the different environmental conditions characterizing farming sites and to propose hypotheses to explain mortality events observed in recent years. Among the most important findings, the disruption of clam's immune response, the spread of Vibrio spp., and the up-regulation of molecular pathways involved in xenobiotic metabolism suggested major environmental stressors affecting clams farmed in sites placed close to Chioggia's inlet, where highest mortality was also observed. Overall, our study provides knowledge-based tools for managing Manila clam farming on-growing areas. In addition, the collected data is a snapshot of the time immediately before the commissioning of MoSE, a system of mobile barriers aimed at protecting Venice from high tides, and will represent a baseline for future studies on the effects of MoSE on clams farming and more in general on the ecology of the Venice Lagoon.
近年来，双壳贝类反复出现的大规模死亡现象在全球范围内显著增加，导致自然种群和养殖种群数量锐减。威尼斯泻湖历来是欧洲菲律宾蛤仔主要产区之一。然而，在过去20年里，年产量下降了75%。虽然气候变化和人为干预可能在自然种群和养殖种群数量减少方面起到了关键作用，但迄今为止，尚无研究从多个层面调查影响养殖菲律宾蛤仔的环境压力因素。在这项工作中，我们对位于距威尼斯泻湖南部入海口不同距离的四个养殖场地养殖的菲律宾蛤仔开展了长期监测活动，整合了（元）基因组学方法（即RNA测序；微生物群特征分析）、生物特征测量以及理化参数。我们的研究能够描述该物种为应对不同养殖场地环境条件所采用的分子机制，并提出假设以解释近年来观察到的死亡事件。在最重要的发现中，蛤仔免疫反应的破坏、弧菌属的传播以及参与异生物质代谢的分子途径的上调表明，靠近基奥贾入海口的养殖场地中影响蛤仔的主要环境压力因素最为严重，在这些场地也观察到了最高的死亡率。总体而言，我们的研究为管理菲律宾蛤仔养殖生长区域提供了基于知识的工具。此外，所收集的数据是摩西系统（旨在保护威尼斯免受高潮影响的移动屏障系统）投入使用前即刻的时间快照，将代表未来关于摩西系统对蛤仔养殖以及更广泛地对威尼斯泻湖生态影响研究的基线。
