Abundance and Distributional Patterns of Benthic Peracarid Crustaceans From the Atlantic Sector of the Southern Ocean and Weddell Sea
Abundance and Distributional Patterns of Benthic Peracarid Crustaceans From the Atlantic Sector of the Southern Ocean and Weddell Sea
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DOI：
10.3389/fmars.2020.554663
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发表时间：
2020-10-07
影响因子：
3.7
通讯作者：
Brandt, Angelika
中科院分区：
文献类型：
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作者：
Di Franco, Davide;Linse, Katrin;Brandt, Angelika
气候变化正在影响南大洋的一些环境变量，这将对海洋生物多样性产生影响。过硬壳类动物是SO底栖动物中最具优势和物种最丰富的一类。迄今为止，我们对环境变量在形成SO过表层组合的丰度和物种组成方面的影响的了解有限，而且关于冰覆盖的影响也是未知的。本研究旨在探讨海冰覆盖、叶绿素a和浮游植物浓度对甲壳纲生物丰度、分布和组合结构的影响。此外，还评估了其他物理参数对过表层丰度的影响，包括深度、温度、盐度、沉积物类型、流速、氧、铁、硝酸盐、硅酸盐和磷酸盐。用底栖雪撬（EBS）在SO的大西洋部分和威德尔海的不同区域取样了旁石虫。采样区域的特征是不同的冰覆盖状况（无冰的南奥克尼群岛、季节性冰覆盖的费尔奇纳海槽和包括古斯塔夫王子海峡在内的南极半岛东部，该海峡以前被常年冰架覆盖）。共收集到甲壳目64766只，经鉴定为5目：片足目、Cumacea目、等足目、Mysidacea目和tanaidae目。丰度最高的分类是片足目，占总丰度的32%，其次是Cumacea（31%）、等足目（29%）、Mysidacea（4%）和tanaidacae（4%）。Filchner海槽的甲壳虫丰度最高，而南奥克尼群岛的甲壳虫丰度最低。冰覆盖是影响环虫丰度格局和组合结构的主要环境驱动因素，后者与冰覆盖和叶绿素-a浓度呈正相关。我们提出海冰与过冰丰度之间的正相关关系可能是由于季节性海冰融化引发的浮游植物大量繁殖，这可能会增加底栖动物的食物供应。气候变化引起的冰覆盖范围和季节变化将强烈影响底栖过礁生物的丰度和组合结构。
Climate change is influencing some environmental variables in the Southern Ocean (SO) and this will have an effect on the marine biodiversity. Peracarid crustaceans are one of the dominant and most species-rich groups of the SO benthos. To date, our knowledge on the influence of environmental variables in shaping abundance and species composition in the SO's peracarid assemblages is limited, and with regard to ice coverage it is unknown. The aim of our study was to assess the influence of sea ice coverage, chlorophyll-a, and phytoplankton concentrations on abundance, distribution and assemblage structure of peracarids. In addition, the influence of other physical parameters on peracarid abundance was assessed, including depth, temperature, salinity, sediment type, current velocity, oxygen, iron, nitrate, silicate and phosphate. Peracarids were sampled with an epibenthic sledge (EBS) in different areas of the Atlantic sector of the SO and in the Weddell Sea. Sampling areas were characterized by different regimes of ice coverage (the ice free South Orkney Islands, the seasonally ice-covered Filchner Trough and the Eastern Antarctic Peninsula including the Prince Gustav Channel which was formerly covered by a perennial ice shelf). In total 64766 individuals of peracarids were collected and identified to order level including five orders: Amphipoda, Cumacea, Isopoda, Mysidacea, and Tanaidacea. Amphipoda was the most abundant taxon, representing 32% of the overall abundances, followed by Cumacea (31%), Isopoda (29%), Mysidacea (4%), and Tanaidacea (4%). The Filchner Trough had the highest abundance of peracarids, while the South Orkney Islands showed the lowest abundance compared to other areas. Ice coverage was the main environmental driver shaping the abundance pattern and assemblage structure of peracarids and the latter were positively correlated with ice coverage and chlorophyll-a concentration. We propose that the positive correlation between sea ice and peracarid abundances is likely due to phytoplankton blooms triggered by seasonal sea ice melting, which might increase the food availability for benthos. Variations in ice coverage extent and seasonality due to climate change would strongly influence the abundance and assemblage structure of benthic peracarids.