Pigments of sediment cores of the Northwest European Continental Margin

In the context of the European OMEX Programme this investigation focused on gradients in the biomass and activity of the small benthic size spectrum along a transect across the Goban Spur from the outer Celtic Sea into Porcupine Abyssal Plain. The effects of food pulses (seasonal, episodic) on this part of the benthic size spectrum were investigated. Sediments sampled during eight expeditions at different seasons covering a range from 200 m to 4800 m water depth were assayed with biochemical bulk measurements: determinations of chloroplastic pigment equivalents (CPE), the sum of chlorophyll a and its breakdown products, provide information concerning the input of phytodetrital matter to the seafloor; phospholipids were analyzed to estimate the total biomass of small benthic organisms (including bacteria, fungi, flagellata, protozoa and small metazoan meiofauna). A new term 'small size class biomass' (SSCB) is introduced for the biomass of the smallest size classes of sediment-inhabiting organisms; the reduction of fluorescein-di-acetate (FDA) was determined to evaluate the potential activity of ester-cleaving bacterial exoenzymes in the sediment samples. […]本研究依托欧洲OMEX计划（OMEX Programme），聚焦沿横跨戈班海脊、从外凯尔特海延伸至豪猪深渊平原的断面，小型底栖生物粒径谱（small benthic size spectrum）的生物量与活性梯度特征。本研究探讨了食物脉冲（季节性、突发性）对该区域底栖生物粒径谱的影响。研究团队在不同季节开展的8次科考航次中，采集了水深区间为200米至4800米的沉积物样品，并通过生化总量检测方法开展分析：其中，叶绿素类色素等效物（chloroplastic pigment equivalents, CPE）——即叶绿素a及其降解产物的总和——可用于指示海底植物碎屑的输入通量；磷脂含量分析则用于估算小型底栖生物的总生物量，涵盖细菌、真菌、鞭毛虫、原生动物以及后生动物小型底栖生物（meiofauna）。本研究引入"小型粒径级生物量（small size class biomass, SSCB）"这一新术语，用于指代沉积物栖息生物中最小粒径级的生物量；此外，通过检测荧光素二乙酸酯（fluorescein-di-acetate, FDA）的降解量，可评估沉积物样品中酯解细菌胞外酶的潜在活性。[…]