Abundance, horizontal and vertical distribution of epipelagic ctenophores and scyphomedusae in the northern Bering Sea in summer 2017 and 2018: Quantification by underwater video imaging analysis

被引：3

作者：

Maekakuchi, Marie ^{[1
,5
]}

Matsuno, Kohei ^{[1
,2
]}

Yamamoto, Jun ^{[3
]}

Abe, Yoshiyuki ^{[4
]}

Yamaguchi, Atsushi ^{[1
,2
]}

机构：

[1] Hokkaido Univ, Fac Grad Sch Fisheries Sci, 3-1-1 Minato Cho, Hakodate, Hokkaido 0418611, Japan

[2] Hokkaido Univ, Arctic Res Ctr, Kita Ku, Kita 21 Nishi 11, Sapporo, Hokkaido 0010021, Japan

[3] Hokkaido Univ, Field Sci Ctr Northern Biosphere, 3-1-1 Minato Cho, Hakodate, Hokkaido 0418611, Japan

[4] Hokkaido Univ, Off Enhancing Inst Capac, Res Dev Sect, Kita Ku, Kita 21,Nishi 10, Sapporo, Hokkaido 0010021, Japan

[5] APA Hotel & Resorts Co Ltd, Minato Ku, Akasaka 3-2-3, Tokyo 1070052, Japan

来源：

DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY | 2020年 / 181卷

基金：

日本学术振兴会;

关键词：

Ctenophores; Scyphomedusae; Northern Bering Sea; Vertical distribution; Horizontal distribution; Imaging analysis; IN-SITU OBSERVATIONS; QUANTITATIVE COMPOSITION; GELATINOUS ZOOPLANKTON; JELLYFISH BLOOMS; AURELIA-AURITA; AGGREGATIONS; ASSOCIATION; BEHAVIOR; BIOMASS; OCEAN;

D O I：

10.1016/j.dsr2.2020.104818

中图分类号：

P7 [海洋学];

学科分类号：

0707 ;

摘要：

We examined the abundance and horizontal and vertical distributions of epipelagic ctenophores and scyphomedusae in the northern Bering Sea using an underwater video camera during July of 2017 and 2018. The effects of environmental and biological parameters on the distribution of these species were evaluated by generalized additive modelling (GAM). In 2017, the dominant ctenophore, Bolinopsis infundibulum, was mainly distributed in the north and west of St. Lawrence Island (SLI), and their vertical distribution varied with the region but not by the time of day. We found that B. infundibulum was distributed in the upper pycnocline north of SLI, but below the pycnocline west of SLI. Biological interactions with other gelatinous zooplankton may explain these regional differences in vertical distribution; GAM analysis revealed a negative interaction between B. infundibulum and the large scyphomedusa, Chrysaora melanaster, which occurred in the upper layer in the west of SLI. B. infundibulum may avoid that layer to reduce feeding competition. For the ctenophore, Beroe sp., vertical and horizontal distributions were similar to those of B. infundibulum, and GAM analysis also revealed a positive interaction for both species. As B. infundibulum is an important prey of Beroe sp., a prey-predator interaction may result from their similar horizontal and vertical distributions. Standing stocks of epipelagic ctenophores and scyphomedusae in 2018 were low compared to those in 2017, by a factor of 1/20 (C. melanaster) and1/90 (Beroe sp.). This might be due to annual differences in water mass in this region, in that the thermal conditions characterized by a high abundance of the dominant B. infundibulum in 2017 (<2 and >8 degrees C) were absent in 2018. As this drastic decrease in standing stock in 2018 was apparent for both ctenophores and scyphomedusae, food availability was hypothesized to be poor that year.

引用

页数：15