Dinoflagellate cyst species composition of recent surface samples (Appendix)

Dinoflagellate cysts and other organic-walled microfossils have been studied in recent surface sediments from the entire Norwegian-Greenland Sea. More than 30 taxa have been recognized, of which only few show a distinct distribution pattern, and allow description of four assemblages. The occurrence of most taxa is related to the relatively warmer waters of the Norwegian Sea. Algidaspaeridium? minutum s.1., Brigantedinium simplex and Impagidinium? pallidum are the only species showing a preference for colder water masses. Two species, I.? pallidum and Nematosphaeropsis labyrinthus are mainly restricted to the oceanic environment, whereas the other species have also been reported from neritic environments in previous studies. Due to the limited knowledge of the ecological and sedimentological factors influencing the occurrence of dinoflagellate cysts in oceanic environments, their distribution in recent sediments can be only related to surface water masses in a broad sense.
Although the distribution of assemblages correlates with specific surface water masses, comparison with assemblages recovered from sediment traps deployed basinwide in the Norwegian-Greenland Sea (Dale and Dale, 1992) revealed some major discrepancies in species composition and percentage abundances. The differences cannot be explained with certainty at the moment, although there is some evidence that transport of dinoflagellate cysts and other fossilizable microplankton in water masses by currents, in sea-ice and sediments may modify the assemblages found in recent oceanic surface sediments from the Norwegian-Greenland Sea.

针对挪威海-格陵兰海（Norwegian-Greenland Sea）全域的现代表层沉积物，学界已对其中产出的沟鞭藻囊孢（dinoflagellate cysts）及其他有机壁微化石（organic-walled microfossils）展开研究。本次研究共识别出30余个分类单元（taxa），其中仅少数类群具备显著分布格局，据此可划分出4个生物组合（assemblages）。多数类群的产出与挪威海相对温暖的水团密切相关。仅*Algidaspaeridium? minutum s.l.*、*Brigantedinium simplex*及*Impagidinium? pallidum*三个物种偏好冷水团环境。另有两个物种，即*I.? pallidum*与*Nematosphaeropsis labyrinthus*，主要局限于远洋环境（oceanic environment）；其余类群在既往研究中亦有在浅海环境（neritic environments）产出的记录。由于目前对远洋环境中影响沟鞭藻囊孢产出的生态与沉积学因素认知不足，仅能从广义层面将其在现代沉积物中的分布与表层水团（surface water masses）建立关联。
尽管各生物组合的分布与特定表层水团具有相关性，但对比挪威海-格陵兰海全盆地部署的沉积物捕集器（sediment traps）所获取的生物组合（Dale与Dale，1992），却发现物种组成与丰度占比（percentage abundances）存在显著差异。目前尚无法确切解释这些差异，尽管已有证据表明：水流、海冰及沉积物所介导的沟鞭藻囊孢与其他可化石化微浮游生物（fossilizable microplankton）在水团中的输运过程，可能会改变挪威海-格陵兰海现代远洋表层沉积物中所发现的生物组合。