Center d'Estudis Avançats de Blanes (CEAB-CSIC), Carrer d'accés a la Cala Sant Francesc 14, 17300 Blanes, Girona, Catalunya, Spain.
Center d'Estudis Avançats de Blanes (CEAB-CSIC), Carrer d'accés a la Cala Sant Francesc 14, 17300 Blanes, Girona, Catalunya, Spain; Envjoy: Carrer dels Almogàvers, 165, 08018 Barcelona, Catalunya, Spain.
Sci Total Environ. 2019 Jul 10;673:790-809. doi: 10.1016/j.scitotenv.2019.04.010. Epub 2019 Apr 3.
The Gulf of Lions (GoL) is among the most productive areas of the Mediterranean Sea, with the Rhône River contributing with as much as 90% of the liquid and solid materials (including anthropogenic chemicals) reaching the area. In this paper, we assessed whether classical descriptive ecology and MaxEnt predictive species distribution modelling were able to provide complementary information when analysing the long-distance influence of the river discharges on the GoL benthic ecosystem. Samples were collected in August 2014 from 12 stations covering the sedimentary plain of the deep submarine delta, from the Gulf of Fos to Gruissan. Sediments were mostly muddy with a high organic carbon and low P and N contents first decreasing and then increasing from east to west. The same pattern occurred for chlorophyll-a, particulate organic carbon and sea surface temperature, and was overall correlated with metal and pollutant contents derived from agricultural, port, urban and industrial sources driven by Rhône outputs. We observed a typical deltaic succession in the benthos, showing a relatively low diversity and including polychaetes (Sternaspis scutata) and holothurians (Oestergrenia digitata) known to be indicators of high sedimentation rates. Overall, benthos showed an inversed pattern regarding environmental variables, an evident consequence of the Rhône River influence. The suitability of some species was either positively or negatively correlated with some of the environmental variables, producing species-specific predicted distribution patterns, with the highest amount of information allowing to predict distributions being mainly provided by organic pollutants. Even with a limited number of available samples, our integrated approach reveals to be a very robust tool to highlight hidden patterns and contributes to improve our knowledge on how river-mediated anthropogenic discharges may influence biodiversity distribution and functional patterns in marine benthic ecosystems.
狮子湾（GoL）是地中海最具生产力的地区之一，罗纳河贡献了多达 90%的到达该地区的液体和固体物质（包括人为化学品）。在本文中，我们评估了经典描述性生态学和 MaxEnt 预测物种分布模型在分析河流排放对 GoL 海底生态系统的远距离影响时是否能够提供互补信息。2014 年 8 月，我们在从福斯湾到格吕松的深海海底三角洲沉积平原上的 12 个站点采集了样本。沉积物主要为泥质，有机碳含量高，磷和氮含量低，从东向西逐渐减少然后增加。叶绿素-a、颗粒有机碳和海面温度也呈现出相同的模式，总体上与罗纳河排放物驱动的农业、港口、城市和工业来源的金属和污染物含量相关。我们观察到海底生物群具有典型的三角洲演替，多样性相对较低，包括多毛类动物（Sternaspis scutata）和海参（Oestergrenia digitata），它们被认为是高沉积速率的指示物。总体而言，海底生物群的环境变量呈反向模式，这是罗纳河影响的明显结果。一些物种的适宜性与某些环境变量呈正相关或负相关，产生了特定物种的预测分布模式，其中提供信息最多的是有机污染物，能够主要预测分布。即使样本数量有限，我们的综合方法也被证明是一种非常强大的工具，可以揭示隐藏的模式，并有助于提高我们对河流介导的人为排放如何影响海洋海底生态系统生物多样性分布和功能模式的认识。
