SOMLIT-Frioul time series (French Research Infrastructure ILICO): long-term core parameter monitoring in the Bay of Marseilles

sno somlit's "frioul" station is located in the gulf of marseille, with a seawater volume of around 4.4 km3 divided into two basins. the eastern part of the gulf is bounded by the city of marseille (population approx. 800,000), which stretches from the nerthe mountain range in the north to the marseilleveyre massif in the south. this gulf, which is largely open to the sea to the south and west, is characterized by a steep slope and the proximity of one of the most important rivers in the mediterranean, the rhône. it includes the côte bleue (land and sea) and the marseille archipelagos. the marseilles region is home to posidonia oceanica meadows, the loggerhead sea turtle (caretta caretta), cetaceans such as the bottlenose dolphin (tursiops truncates), and mollusks of community interest. the frioul archipelago divides the gulf into two basins of unequal size, which communicate via a sill located between the islet of if and the pointe d'endoume. the depth is around twenty meters.the northern basin, also known as the marseilles harbor, covers an area of around 65 km², with an average depth of 52 m. it is bordered to the north by the steep slopes of the nerthe chain, and to the south by the frioul archipelago. it is bounded to the north by the steep slopes of the nerthe chain, and to the south by the frioul archipelago. along the axis of the rade, the fairly steep slope at the coast (2.5%) eases off towards the open sea, and the 70 m isobath, which penetrates fairly profoundly into the basin, delimits a vast silted-up plateau no more than 80 m deep. the southern basin, located between the marseilleveyre massif and the notre dame de la garde hill, covers a surface area of just 35 km², with an average depth of around 30 m. the gulf's seaward limit corresponds to the 50 m isobath. also noteworthy is the remarkable regularity of the basin's steepest slope (from 0.6 to 1%), oriented ene-osw, which ends well beyond the gulf at depths in excess of 90 m. since 1995, the somlit-marseille hydrological quality monitoring program has been operated by the cnrs (french national center for scientific research) to characterize the general state of water masses in the bay of marseille at fortnightly intervals, and to assess their evolution in response to climate change.it is an integral part of the national somlit (service d'observation des milieux littoraux) network, accredited by insu/cnrs (https://www.somlit.fr/), which comprises 12 observation stations distributed throughout the french coastline. the station sampled is located in the median part of the gulf of marseille, around 5 km from the coast, close to the frioul archipelago on a sandy bottom, at a depth of 60 m (43.2417°n; 5.29167°e). the initial choice of site was dictated by: its local and regional environmental interest - a strictly marine station, but with a marked continental influence. this point was initially the site of the sofcom monitoring program set up in 1994 and has been the subject of much previous work by researchers at the endoume marine station. accessibility using the station's own resources allows regular visits and, in the (near) future, automated measurement of certain parameters. it is located off the routes of large commercial vessels. at present, outings are made on board the station ship antedon ii, to carry out the following operations: a continuous profile using a multiparameter probe between 0 and 55m. three water samples (surface, maximum chlorophyll, and bottom) for laboratory analysis.since january 2009, monitoring of natural isotopic abundances (d15n and d13c) and sampling for pico and ultra-planktonic communities have begun.additional measurements or sampling requested by research teams and programs (phytoplankton, zooplankton netting, molecular biology, bio-optical measurements, primary production, etc.).some fifteen parameters are measured according to standard procedures accredited by the entire network community. measurement is carried out in accordance with iso 17025. somlit-marseille also collects phytoplankton samples for sno phytobs. the site is also at the heart of an automated measurement network, combining sno moose and coast-hf measurement points. this measurement network constitutes a multi-instrument platform comprising : a site for collecting atmospheric deposits and meteorological measurements an automatic monitoring station for rhone river inflows at arles (sora) a network of sensors between the mouth of the rhône and the bay of marseille an instrumented buoy in the bay of marseille

索姆利特海洋站位于马赛湾内，该湾位于马赛湾，海水总体积约为4.4立方千米，分为两个海域。马赛湾的东部以马赛市（人口约80万）为界，北起奈尔特山脉，南至马赛韦尔山群。该湾南部和西部面向大海，以陡峭的坡度和靠近地中海最重要河流之一的罗讷河而著称。它包括蓝色海岸（陆地和海洋）以及马赛群岛。马赛地区拥有海洋莼草地、 loggerhead sea turtle（海龟）（caretta caretta）、如瓶鼻海豚（tursiops truncates）等鲸类以及具有社区利益的软体动物。弗里奥尔群岛将该湾划分为两个大小不等的海域，通过位于伊夫岛和恩多姆角之间的浅滩相连。水深约为二十米。北部海域，亦称马赛港，面积约为65平方公里，平均水深52米。北部以奈尔特山脉的陡峭山坡为界，南部以弗里奥尔群岛为界。在航道轴线上，海岸附近相对陡峭的斜坡（2.5%）向开阔海面逐渐缓和，而深度为70米的等深线深入海底，界定了一个深度不超过80米的广阔淤泥平原。南部海域位于马赛韦尔山群和圣母加德山之间，面积仅为35平方公里，平均水深约为30米。海湾面向海洋的界限对应于50米的等深线。值得注意的是，该海域最陡斜坡（从0.6%至1%）的规律性十分显著，其方向为东北至西南，延伸至海湾以外超过90米的深度。自1995年以来，索姆利特-马赛水文质量监测项目由法国国家科学研究中心（CNRS）运营，以每隔两周的频率对马赛湾水体的总体状况进行表征，并评估其随气候变化而发生的演变。它是国家索姆利特（服务观测海岸带环境）网络的一部分，该网络由INSU/CNRS（https://www.somlit.fr/）认证，包括12个分布在全国海岸线上的观测站。观测站位于马赛湾中部，距离海岸约5公里，靠近弗里奥尔群岛，位于沙质海底，水深60米（43.2417°N；5.29167°E）。最初选择该地点是基于其局部和区域环境利益——一个纯粹海洋站，但具有明显的大陆影响。这一点最初是1994年设立的sofcom监测项目的地点，并且一直是恩多姆海洋站研究人员先前工作的主题。利用站内资源进行可达性，允许定期访问，并在（近）将来自动测量某些参数。它位于大型商业船只的航线之外。目前，乘坐站船Antedon II进行以下操作：使用多参数探测器在0至55米之间进行连续剖面测量。采集三个水样（表面、最大叶绿素含量和底部）进行实验室分析。自2009年1月起，开始了对自然同位素丰度（d15N和d13C）的监测和对浮游生物群落进行采样。根据整个网络社区认可的标准程序，对约十五个参数进行测量。测量按照ISO 17025标准执行。索姆利特-马赛还收集浮游植物样品供SNO Phytobs使用。该地点也是自动化测量网络的核心，该网络结合了SNO Moose和Coast-HF测量点。这个测量网络构成了一个多仪器平台，包括：收集大气沉降物和气象测量的地点；位于阿维尼翁的罗讷河入流自动监测站（Sora）；罗讷河口与马赛湾之间的传感器网络；马赛湾的装备浮标。