Instituto Argentino de Oceanografía, Universidad Nacional del Sur (UNS)-CONICET, Camino Carrindanga 7.5 km, B8000FWB, Bahía Blanca, Argentina.
Centro de Emprendedorismo y Desarrollo Territorial Sostenible (CEDETS), Universidad Provincial del Sudoeste (UPSO)-Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC), Bahía Blanca, Argentina.
Environ Monit Assess. 2021 Mar 20;193(4):201. doi: 10.1007/s10661-021-08888-4.
The influence of microphytobenthic community on the composition of sedimentary organic matter was evaluated in two Bahía Blanca estuary microhabitats contrasting in vegetation and hydrodynamic conditions; namely, S1 located in a Sarcocornia perennis saltmarsh with macroscopic microbial mats and S2 in a mudflat without macroscopic microbial mats or vegetation. Moisture, organic matter, chlorophyll a, phaeopigments, carbohydrates (CH), proteins (PRT), and abundance and structure of microphytobenthic community were evaluated in surface sediments. Higher moisture was observed at S2 and was related to the proximity of this site to the subtidal zone and the effect of the environmental variables temperature and rain. No significant differences were found in organic matter content between sites; however, at S1, a higher concentration was registered during winter and early spring associated to the period of higher microphytobenthic biomass. Chlorophyll a and phaeopigments were higher at S1, attributed to the higher microphytobenthos abundance at this site. Differences in microphytobenthos were observed not only in quantity but also in community structure since at S1 filamentous cyanobacteria dominated the community, whereas at S2, higher abundance of centric diatoms and the absence of cyanobacteria were observed during most of the study. S1 showed higher concentration of proteins and carbohydrates which could be attributed to the higher production of fresh organic matter by microphytobenthos. The total protein and carbohydrate concentrations allowed us to classify both microhabitats into the meso-oligotrophic category, contrasting with the classification made by other authors using water column proxies.
在两个具有不同植被和水动力条件的 Bahía Blanca 河口小生境中，评估了微型底栖生物群落对沉积有机质组成的影响；即 S1 位于具有宏观微生物席的 Sarcocornia perennis 盐沼中，而 S2 位于没有宏观微生物席或植被的泥滩中。在表层沉积物中评估了水分、有机质、叶绿素 a、类胡萝卜素、碳水化合物 (CH)、蛋白质 (PRT) 以及微型底栖生物群落的丰度和结构。S2 的水分较高，这与该地点靠近潮下带以及温度和降雨等环境变量的影响有关。两个地点的有机质含量没有显著差异；然而，在 S1，冬季和早春期间记录到更高的浓度，这与更高的微型底栖生物生物量时期有关。S1 的叶绿素 a 和类胡萝卜素较高，这归因于该地点的微型底栖生物丰度较高。微型底栖生物不仅在数量上而且在群落结构上存在差异，因为在 S1 丝状蓝藻占主导地位，而在 S2，在研究的大部分时间里，发现了更高的中心硅藻丰度和蓝藻的缺失。S1 表现出更高的蛋白质和碳水化合物浓度，这可能归因于微型底栖生物产生的新鲜有机物质更高。总蛋白质和碳水化合物浓度使我们能够将这两个小生境归入中-寡营养类别，与使用水柱指标的其他作者的分类形成对比。
