Ifremer, BEEP, Univ Brest, Plouzané, France.
ENIB - École Nationale d'Ingénieurs de Brest, Plouzané, France.
PLoS One. 2024 Oct 31;19(10):e0309463. doi: 10.1371/journal.pone.0309463. eCollection 2024.
Living benthic foraminifera, known as environmental bio-indicators of both natural and anthropogenic conditions in marine environments, were investigated in the coastal environment of Roscoff Aber Bay (Brittany, France). Eight sampling sites subject to natural variations (freshwater inputs, tides) and/or anthropogenic impacts (pollution, eutrophication) were studied over four seasons in 2021-2022 (November, February, May, August). We sought to understand the spatial distribution of foraminiferal populations within and between sampling sites over the different seasons and to identify sensitive species and those tolerant to anthropogenic impacts. To this end, sedimentary and biogeochemical characteristics of the sediments were examined by measuring grain size, temperature, oxygen, salinity, pH, environmental pigment concentration (chl a and phaeopigments), total organic carbon (TOC), isotopic ratios of carbon (δ13C), nitrogen (δ15N) and sulfide (δ34S), and chl a fluorescence. Considering these parameters as potential driving factors, four environments were distinguished among the sampling sites: open water, terrestrial, oligotrophic and eutrophic. These showed an increasing gradient of organic supply as well as very different microbial activities, highlighted by carbon and sulfide isotopic ratios. Foraminiferal population study revealed the dominant species characterising these main environments. The lowest abundance but highest diversity of foraminifera was found in the harbour site, associated with the dominance of Haynesina germanica, suggesting this species is tolerant to eutrophic environments and anthropogenic impacts. Open water was dominated by Ammonia beccarii and Elphidium crispum, while Quinqueloculina seminula was the most abundant species in the site with the greatest terrestrial influence. Interestingly, the observed organic enrichment of the harbour due to anthropogenic activities (fisheries, waste deposits, etc.) does not seem to significantly affect foraminiferal diversity. Overall, the benthic foraminiferal species in Roscoff Aber Bay appear to be an excellent proxy for marine environmental conditions under various natural and anthropogenic influences.
生活在海底的有孔虫，被认为是海洋环境中自然和人为条件的环境生物指标，在法国布列塔尼的罗什福尔阿贝尔湾的沿海环境中进行了研究。2021 年至 2022 年的四个季节中，研究了八个受到自然变化（淡水输入、潮汐）和/或人为影响（污染、富营养化）的采样点。我们试图了解不同季节内和采样点之间有孔虫种群的空间分布，并确定敏感物种和对人为影响有耐受性的物种。为此，通过测量粒度、温度、氧气、盐度、pH 值、环境色素浓度（chl a 和 phaeopigments）、总有机碳（TOC）、碳（δ13C）、氮（δ15N）和硫（δ34S）的同位素比，以及 chl a 荧光，检查了沉积物的沉积和生物地球化学特征。考虑到这些参数是潜在的驱动因素，将采样点之间的四个环境区分开来：开阔水域、陆地、贫营养和富营养。这些环境表现出有机供应的递增梯度，以及微生物活性的非常不同，这突出了碳和硫同位素的作用。有孔虫种群研究揭示了主导这些主要环境的优势物种。在港口站点发现了最低丰度但最高多样性的有孔虫，与 Haynesina germanica 的优势有关，表明该物种对富营养环境和人为影响具有耐受性。开阔水域主要由 Ammonia beccarii 和 Elphidium crispum 主导，而 Quinqueloculina seminula 是受陆地影响最大的站点中最丰富的物种。有趣的是，由于人为活动（渔业、废物堆积等）导致港口有机富集会对有孔虫多样性产生明显影响。总的来说，罗什福尔阿贝尔湾的底栖有孔虫物种似乎是海洋环境在各种自然和人为影响下的一个极好的指标。
