摘要
Traditionally, benthic metabolism in sublittoral permeable sands have not been widely studied, although these sands can have a direct and transcendental impact in coastal ecosystems. This study aims to determine oxygen and nutrient fluxes at the sediment–water interface and the study of possible interactions among environmental variables and the benthic metabolism in well-sorted fine sands. Eight sampling campaigns were carried out over the annual cycle in the eastern coast of Spain (NW Mediterranean) at 9 m depth station with permeable bottoms. Water column and sediment samples were collected in order to determine physico-chemical and biological variables. Moreover, in situ incubations were performed to estimate the exchange of dissolved solutes in the sediment–water interface using dark and light benthic chambers. Biochemical compounds at the sediment surface ranged between 160 and 744 μg g−1 for proteins, 296 and 702 μg g−1 for carbohydrates, and between 327 and 1224 μg C g−1 for biopolymeric carbon. Chloroplastic pigment equivalents in sediments were mainly composed by chlorophyll a (1.81–2.89 μg g−1). These sedimentary organic descriptors indicated oligotrophic conditions according to the biochemical approach used. In this sense, the most abundant species in the macrobenthic community were sensitive to organic enrichment. In dark conditions, benthic fluxes behaved as a sink of oxygen and a source of nutrients. Oxygen fluxes (between −26,610 and −10,635 μmol m−2 d−1) were related with labile organic fraction (r=−0.86, p<0.01 with biopolymeric carbon; r=−0.91, p<0.01 with chloroplastic pigment equivalents). Daily fluxes of dissolved oxygen, that were obtained by adding light and dark fluxes, were only positive in spring campaigns (6966 μmol m−2 d−1) owing to the highest incident irradiance levels (r=0.98, p<0.01) that stimulate microphytobenthic primary production. Microphytobenthos played an important role on benthic metabolism and was the main primary producer in this coastal ecosystem. However, an average annual uptake of 31 mmol m−2 d−1 of oxygen and a release of DIN and Si(OH)4 (329 and 68 mmol m−2 d−1 respectively) were estimated in these bottoms, which means heterotrophic conditions.
摘要译文
传统上，亚水下渗透性沙地中的底栖生物代谢尚未得到广泛的研究，尽管这些沙在沿海生态系统中可能具有直接和超越的影响。y旨在确定沉积物 - 水界面处的氧气和营养物流量，以及在良好分选的细砂中环境变量和底栖代谢之间可能的相互作用的研究。在西班牙东海岸（地中海西北部）的9米深处，每年进行八次采样活动，并在底部渗透水。收集水柱和沉积物样品以确定物理化学和生物学变量。此外，进行原位孵化，以估计沉积物 - 水界面中使用黑暗和浅底层室的溶解溶质的交换。对于蛋白质沉积物表面的生化化合物在160和744μgg -1之间，碳水化合物在296和702μgg -1之间，生物聚合物碳在327-1224μgC g -1之间。叶绿素a（1.81-2.89μgg -1）主要由沉积物中的叶绿素色素等价物组成。根据所使用的生物化学方法，这些沉积有机描述符指示了营养不良条件。在这个意义上，大型底栖动物群落中最丰富的物种对有机物浓缩敏感。在黑暗的条件下，底栖通量表现为氧气的吸收和营养的来源。氧气通量（-26,610和-10,635μmolm -2·d -1之间）与不稳定有机组分（r \x3d -0.86，p 0.01与生物聚合物碳; r \x3d -0.91，p 0。01与叶绿素色素等价物）。日光通量的溶解氧，这是通过添加光和黑暗的通量，在春季（6966μmolm -2·d -1·s -1），由于入射辐照水平最高（r \x3d 0.98，p 0.01）生产。微底栖动物对底栖新陈代谢起着重要的作用，是该沿海生态系统的主要生产者。然而，平均年吸收量为31mmol m -2·d -1 -1氧和释放DIN和Si（OH）4（329和68mmol m -2分别）在这些底部估计，这意味着异养条件。
J. Sospedra; S. Falco; T. Morata; I. Gadea; M. Rodilla. Benthic fluxes of oxygen and nutrients in sublittoral fine sands in a north-western Mediterranean coastal area[J]. Continental Shelf Research, 2015,97: 32–42