Seabird densities and species and hydrographic features across Amchitka Pass, Aleutian Islands
Seabird densities and species and hydrographic features across Amchitka Pass, Aleutian Islands
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阿留申群岛阿姆奇特卡山口的海鸟密度和物种以及水文特征
DOI：
10.1007/s12562-018-1259-5
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发表时间：
2018
影响因子：
1.9
通讯作者：
Y. Watanuki
中科院分区：
文献类型：
--
作者：
B. Nishizawa;H. Onishi;Y. Watanuki
为了研究影响海鸟群落的中尺度物理和生物因素，在夏季从北太平洋穿越阿留申群岛中部阿姆奇特卡山口到白令海的一次航行期间，进行了基于船的海鸟普查。同时进行了潜在猎物生物量和电流的声学调查，以及温度、盐度和荧光垂直剖面的电导率-温度深度剖面仪测量。阿姆奇特卡山口的海鸟密度和物种数最高（283 只鸟 km−2，17 种），声学测定的生物量最高，其次是白令海盆地（100 只鸟 km−2，13 种）和北太平洋盆地（4 只鸟 km−2，7 种）。阿姆奇特卡山口的凤头海雀Aethia cristatella 占主导地位（数量占95%），而白令海盆地的短尾海鸥Ardenna tenuirostris 占主导地位（数量占92%）。白令海盆地的表面荧光（中值：1.3 伏）高于阿姆奇特卡山口（0.9）和北太平洋盆地（0.6）。在通道内，冠海雀的数量在岩台北部地区最高，那里的水柱混合得很好，向北流动的潮汐流增加了地下层中声学确定的生物量的浓度。因此，我们假设小型酸类被潮汐冲击窗台导致的猎物聚集所吸引。
To examine mesoscale physical and biological factors affecting seabird communities, boat-based seabird censuses were conducted during a single cruise from the North Pacific to the Bering Sea across Amchitka Pass, central Aleutian Islands, during summer. Acoustic surveys of potential prey biomass and currents, and conductivity-temperature-depth profiler measurements for vertical profiles of the temperature, salinity, and fluorescence, were conducted simultaneously. The seabird density and number of species were highest in Amchitka Pass (283 birds km−2, 17 species), where the acoustically determined biomass was the highest, followed by the Bering Sea basin (100 birds km−2, 13 species) and North Pacific basin (4 birds km−2, seven species). Crested aukletsAethia cristatellawere dominant (95% in number) in Amchitka Pass, while short-tailed shearwatersArdenna tenuirostriswere dominant (92% in number) in the Bering Sea basin. Surface fluorescence was higher in the Bering Sea basin (median: 1.3 volts) than in Amchitka Pass (0.9) and the North Pacific basin (0.6). Within the pass, the number of crested auklets was highest over the northern part of the sill, where the water column was well mixed, and the northward-flowing tidal currents increased the concentration of acoustically determined biomass in the subsurface layer. Thus, we hypothesize that small alcids were attracted to an aggregation of prey that resulted from tidal currents impinging on the sill.