Fontana Luiz Francisco, Belart Pierre, Bonetti Carla, Junior Décio Semensatto, Frontalini Fabrizio, Martínez-Colón Michael, Bouchet Vincent M P, Laut Lazaro
Universidade Federal do Estado do Rio de Janeiro - UNIRIO, Laboratório de Micropaleontologia - LABMICRO, Av. Pasteur 458, s. 500, Urca, Rio de Janeiro, RJ 22290-240, Brazil.
Universidade Federal de Santa Catarina - UFSC, Campus Universitário Reitor João David Ferreira Lima, s/n°, 88040-900, Trindade, Florianópolis, SC, Brazil.
Sci Total Environ. 2024 Dec 20;957:177650. doi: 10.1016/j.scitotenv.2024.177650. Epub 2024 Nov 29.
Foraminifera could be used as indicators to evaluate the impacts of oil spills because the crude oil causes several disturbances on the development and reproduction of the species. However, little is known about the relationship between mangrove species and this pollutant. Foraminiferal assemblages were studied in 22 surface sediment samples collected from a mangrove in Guanabara Bay (Brazil) that was severely impacted by an oil spill six years earlier. The foraminiferal responses to the environmental stress helped to determine the most degraded areas. Elevated concentrations of aromatic compounds and potentially bioavailable heavy metals, with contamination levels up to nine times higher compared to the pre-industrial period in the Guanabara Bay. The dominance of anaerobic bacteria, and high esterase enzyme activity (ESTE) suggest that the bacterial community is metabolizing the hydrocarbons in the sediments. Despite these stressors, density and diversity of living foraminifera are comparable to values observed in less impacted Brazilian mangroves. Species distribution patterns reveal an environmental gradient across the mangrove with numerous species increasing their relative abundance towards the areas topographically lower and with higher levels of pollutants and ESTE. Specifically, Caronia exilis, Tiphotrocha comprimata, Ammobaculites exiguus, Textularia paranaguaensis, Ammotium cassis, Ammobaculites dilatatus, Polyssaccamina hipohalina, Siphotrochammina lobata, Ammonia tepida, Ammotium morenoi, Miliammina fusca, Entzia macrescens, Trochammina squamata and Paratrochammina clossi are inferred as pollution-tolerant taxa. This integrated geochemical, microbiological and ecological approach applied to assess the sediment quality in a complex ecosystem has important implications for the use of living foraminifera in recovery stage assessments and biomonitoring plans.
有孔虫可作为评估石油泄漏影响的指标，因为原油会对该物种的发育和繁殖造成多种干扰。然而，对于红树林物种与这种污染物之间的关系却知之甚少。对从瓜纳巴拉湾（巴西）一处红树林采集的22个表层沉积物样本中的有孔虫组合进行了研究，该红树林在六年前受到了一次严重的石油泄漏影响。有孔虫对环境压力的反应有助于确定受污染最严重的区域。芳香族化合物和潜在生物可利用重金属的浓度升高，污染水平比瓜纳巴拉湾工业化前时期高出九倍。厌氧细菌的优势以及高酯酶活性（ESTE）表明细菌群落正在代谢沉积物中的碳氢化合物。尽管存在这些压力源，但活有孔虫的密度和多样性与在受影响较小的巴西红树林中观察到的值相当。物种分布模式揭示了整个红树林的环境梯度，许多物种朝着地形较低、污染物和ESTE水平较高的区域相对丰度增加。具体而言，推断微小卡罗尼有孔虫、压缩尖管有孔虫、微小砂杆有孔虫、巴拉那瓜纹理有孔虫、卡西砂堆有孔虫、膨胀砂杆有孔虫、低盐多袋砂虫、叶状管袋砂虫、温热小泡有孔虫、莫雷诺砂堆有孔虫、纺锤串珠虫、大网虫、鳞状管栖有孔虫和克洛西副管栖有孔虫为耐污染类群。这种应用于评估复杂生态系统中沉积物质量的综合地球化学、微生物学和生态学方法，对于在恢复阶段评估和生物监测计划中使用活有孔虫具有重要意义。
