Biogeochemistry of sterols in plankton, settling particles and recent sediments in a cold ocean ecosystem (Trinity Bay, Newfoundland)
Biogeochemistry of sterols in plankton, settling particles and recent sediments in a cold ocean ecosystem (Trinity Bay, Newfoundland)
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冷海洋生态系统中浮游生物、沉降颗粒和近期沉积物中甾醇的生物地球化学（纽芬兰三一湾）
DOI：
10.1016/s0304-4203(01)00066-4
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发表时间：
2001
期刊：
影响因子：
3
通讯作者：
R. Helleur
中科院分区：
文献类型：
--
作者：
E. Hudson;C. Parrish;R. Helleur
在一项多学科研究的背景下，以确定当前和过去的生态系统健康和有机物质来源的相对贡献（海洋与陆地和自然与人为输入），甾醇测定浮游生物，沉降颗粒和沉积物从Trinity湾，纽芬兰，亚极地大西洋生态系统。中心硅藻角毛藻属，海链藻属和丹麦细柱藻在浮游生物样品中均占显著地位，沉降颗粒中以中心硅藻为主。浮游生物样本中含有0.4±0.4 mg/g dw（1995年）或1.4±1.3 mg/g dw（1996年）的总甾醇，其中胆甾-5，24-二烯-3 β-醇（平均占总甾醇的26%）、胆甾-5-烯-3 β-醇（24%）和胆甾-5，22（E）-二烯-3 β-醇（13%）是主要的甾醇，表明硅藻和浮游动物来源。在沉降颗粒物中，胆甾-5，24-二烯-3 β-醇（24%）、胆甾-5-烯-3 β-醇（24%）、胆甾-5，22（E）-二烯-3 β-醇（13%）和24-甲基胆甾-5，22（E）-二烯-3 β-醇（9%）的显著性再次表明主要来源于海洋。不同采样期浮游生物和沉降颗粒物的甾醇组成表现出高度的一致性。高等植物C29甾醇（特别是24-乙基胆甾-5-烯-3 β-醇，9-26%）在近岸和近海沉积物中均很突出。在30厘米的沉积物岩芯中没有观察到总甾醇或单个甾醇的减少趋势，表明整体保存良好。在近海沉积物、浮游生物或沉降颗粒物中未检测到5β-甾烷醇，如5β-胆甾烷-3 β-醇（粪甾烷醇），只有低水平（5β-胆甾烷-3 β-醇最高。4.4%，5β-胆甾烷-3 α-醇max. 5.1%）在某些近岸沉积物中。这表明，纽芬兰农村地区未经处理的污水排放正在有效地降解或分散，或者投入物高度本地化。根据甾醇组成对沉积物中有机质的来源进行了分析。这突出了陆地对海洋沉积物中甾醇的巨大贡献（高达58%的甾醇近岸，24%离岸），并表明海洋甾醇的降解或有效回收。
In the context of a multidisciplinary study to determine current and past ecosystem health and the relative contributions of sources of organic matter (marine vs. terrestrial and natural vs. anthropogenic input), sterols were determined in plankton, settling particles and sediments from Trinity Bay, Newfoundland, a sub-polar Atlantic Ocean ecosystem. The centric diatoms Chaetoceros spp., Thalassiosira spp. and Leptocylindrus danicus were all prominent in the plankton samples, and centric diatoms predominated in the settling particles. Plankton samples contained 0.4±0.4 mg/g dw (1995) or 1.4±1.3 mg/g dw (1996) total sterols, with cholesta-5,24-dien-3β-ol (mean 26% of total sterols), cholest-5-en-3β-ol (24%) and cholesta-5,22(E)-dien-3β-ol (13%) chief among these, denoting diatom and zooplankton sources. In settling particles, the prominence of cholesta-5,24-dien-3β-ol (24%), cholest-5-en-3β-ol (24%), cholesta-5,22(E)-dien-3β-ol (13%) and 24-methylcholesta-5,22(E)-dien-3β-ol (9%) again suggested mainly marine sources. The sterol composition of plankton and settling particles from different sampling periods showed a high degree of consistency. Higher plant C29sterols (notably 24-ethylcholest-5-en-3β-ol, 9–26%) were prominent in sediments from both inshore and offshore sites. No decreasing trend in total or individual sterols was observed down the 30-cm sediment cores, suggesting good overall preservation. No 5β-stanols such as 5β-cholestan-3β-ol (coprostanol) were detected in offshore sediments, plankton or settling particles, with only low levels (5β-cholestan-3β-ol max. 4.4%, 5β-cholestan-3α-ol max. 5.1%) in certain inshore sediments. This suggests that raw sewage discharges in rural Newfoundland are being efficiently degraded or dispersed, or that inputs are highly localized. Source apportionation of organic matter in the sediment samples based on sterol composition was attempted. This highlighted the large terrestrial contribution to the sterols in marine sediments (up to 58% of sterols inshore, 24% offshore) and suggests either degradation or effective recycling of marine sterols.