Doya Carolina, Chatzievangelou Damianos, Bahamon Nixon, Purser Autun, De Leo Fabio C, Juniper S Kim, Thomsen Laurenz, Aguzzi Jacopo
Instituto de Ciencias del Mar (ICM-CSIC), Barcelona, Spain.
Jacobs University Bremen, Bremen, Germany.
PLoS One. 2017 May 30;12(5):e0176917. doi: 10.1371/journal.pone.0176917. eCollection 2017.
Knowledge of the processes shaping deep-sea benthic communities at seasonal scales in cold-seep environments is incomplete. Cold seeps within highly dynamic regions, such as submarine canyons, where variable current regimes may occur, are particularly understudied. Novel Internet Operated Vehicles (IOVs), such as tracked crawlers, provide new techniques for investigating these ecosystems over prolonged periods. In this study a benthic crawler connected to the NEPTUNE cabled infrastructure operated by Ocean Networks Canada was used to monitor community changes across 60 m2 of a cold-seep area of the Barkley Canyon, North East Pacific, at ~890 m depth within an Oxygen Minimum Zone (OMZ). Short video-transects were run at 4-h intervals during the first week of successive calendar months, over a 14 month period (February 14th 2013 to April 14th 2014). Within each recorded transect video megafauna abundances were computed and changes in environmental conditions concurrently measured. The responses of fauna to environmental conditions as a proxy of seasonality were assessed through analysis of abundances in a total of 438 video-transects (over 92 h of total footage). 7698 fauna individuals from 6 phyla (Cnidaria, Ctenophora, Arthropoda, Echinodermata, Mollusca, and Chordata) were logged and patterns in abundances of the 7 most abundant taxa (i.e. rockfish Sebastidae, sablefish Anoplopoma fimbria, hagfish Eptatretus stoutii, buccinids (Buccinoidea), undefined small crabs, ctenophores Bolinopsis infundibulum, and Scyphomedusa Poralia rufescens) were identified. Patterns in the reproductive behaviour of the grooved tanner crab (Chionnecetes tanneri) were also indicated. Temporal variations in biodiversity and abundance in megabenthic fauna was significantly influenced by variabilities in flow velocity flow direction (up or down canyon), dissolved oxygen concentration and month of study. Also reported here for the first time are transient mass aggregations of grooved tanner crabs through these depths of the canyon system, in early spring and likely linked to the crab's reproductive cycle.
关于在季节性尺度上塑造冷泉环境中深海底栖生物群落的过程，我们了解得并不完整。在诸如海底峡谷等高度动态的区域内，可能会出现变化的水流状况，而这些区域的冷泉尤其缺乏研究。新型的互联网操作车辆（IOV），如履带式爬行器，为长时间研究这些生态系统提供了新技术。在本研究中，一个与由加拿大海洋网络运营的海王星海底电缆基础设施相连的底栖爬行器，被用于监测东北太平洋巴克利峡谷一个冷泉区域60平方米范围内的群落变化，该区域位于约890米深的低氧区（OMZ）内。在连续日历月的第一周，每隔4小时进行一次短视频样带监测，持续14个月（2013年2月14日至2014年4月14日）。在每个记录的样带视频中，计算大型动物的丰度，并同时测量环境条件的变化。通过分析总共438个视频样带（超过92小时的总视频片段）中的丰度，评估动物对作为季节性代理的环境条件的反应。记录了来自6个门（刺胞动物门、栉水母动物门、节肢动物门、棘皮动物门、软体动物门和脊索动物门）的7698个动物个体，并确定了7个最丰富类群（即石首鱼科、裸盖鱼、盲鳗、骨螺科、未定义的小螃蟹、栉水母Bolinopsis infundibulum和钵水母Poralia rufescens）的丰度模式。还指出了带沟 Tanner蟹（Chionnecetes tanneri）的繁殖行为模式。大型底栖动物的生物多样性和丰度的时间变化受到流速、流向（峡谷上下游）、溶解氧浓度和研究月份变化的显著影响。本文还首次报道了早春时节带沟 Tanner蟹在峡谷系统这些深度的短暂大规模聚集，这可能与螃蟹的繁殖周期有关。
