Distribution of Arctic and Pacific copepods and their habitat in the northern Bering and Chukchi seas

The advection of warm Pacific water and the reduction in sea ice in the western Arctic Ocean may influence the abundance and distribution of copepods, a key component of food webs. To quantify the factors affecting the abundance of copepods in the northern Bering and Chukchi seas, we constructed hab...

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Main Authors: H. Sasaki, K. Matsuno, A. Fujiwara, M. Onuka, A. Yamaguchi, H. Ueno, Y. Watanuki, T. Kikuchi
Format: Article
Language:English
Published: Copernicus Publications 2016-08-01
Series:Biogeosciences
Online Access:http://www.biogeosciences.net/13/4555/2016/bg-13-4555-2016.pdf
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author H. Sasaki
K. Matsuno
A. Fujiwara
M. Onuka
A. Yamaguchi
H. Ueno
Y. Watanuki
T. Kikuchi
author_facet H. Sasaki
K. Matsuno
A. Fujiwara
M. Onuka
A. Yamaguchi
H. Ueno
Y. Watanuki
T. Kikuchi
author_sort H. Sasaki
collection DOAJ
description The advection of warm Pacific water and the reduction in sea ice in the western Arctic Ocean may influence the abundance and distribution of copepods, a key component of food webs. To quantify the factors affecting the abundance of copepods in the northern Bering and Chukchi seas, we constructed habitat models explaining the spatial patterns of large and small Arctic and Pacific copepods separately. Copepods were sampled using NORPAC (North Pacific Standard) nets. The structures of water masses indexed by principle component analysis scores, satellite-derived timing of sea ice retreat, bottom depth and chlorophyll <i>a</i> concentration were integrated into generalized additive models as explanatory variables. The adequate models for all copepods exhibited clear continuous relationships between the abundance of copepods and the indexed water masses. Large Arctic copepods were abundant at stations where the bottom layer was saline; however they were scarce at stations where warm fresh water formed the upper layer. Small Arctic copepods were abundant at stations where the upper layer was warm and saline and the bottom layer was cold and highly saline. In contrast, Pacific copepods were abundant at stations where the Pacific-origin water mass was predominant (i.e. a warm, saline upper layer and saline and a highly saline bottom layer). All copepod groups showed a positive relationship with early sea ice retreat. Early sea ice retreat has been reported to initiate spring blooms in open water, allowing copepods to utilize more food while maintaining their high activity in warm water without sea ice and cold water. This finding indicates that early sea ice retreat has positive effects on the abundance of all copepod groups in the northern Bering and Chukchi seas, suggesting a change from a pelagic–benthic-type ecosystem to a pelagic–pelagic type.
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spelling doaj.art-82fa91d440f64bd4a01090eafd86d12e2022-12-21T19:43:44ZengCopernicus PublicationsBiogeosciences1726-41701726-41892016-08-0113154555456710.5194/bg-13-4555-2016Distribution of Arctic and Pacific copepods and their habitat in the northern Bering and Chukchi seasH. Sasaki0K. Matsuno1A. Fujiwara2M. Onuka3A. Yamaguchi4H. Ueno5Y. Watanuki6T. Kikuchi7Arctic Environment Research Center, National Institute of Polar Research, 10-3 Midori-cho, Tachikawa, Tokyo 190-8518, JapanArctic Environment Research Center, National Institute of Polar Research, 10-3 Midori-cho, Tachikawa, Tokyo 190-8518, JapanJapan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka, Kanagawa 237-0061, JapanGraduate School of Environmental Science, Hokkaido University, N10W5, Sapporo, Hokkaido 060-0810, JapanGraduate School of Fisheries Sciences, Hokkaido University, 3-1-1 Minato-cho, Hakodate, Hokkaido 041-8611, JapanGraduate School of Fisheries Sciences, Hokkaido University, 3-1-1 Minato-cho, Hakodate, Hokkaido 041-8611, JapanGraduate School of Fisheries Sciences, Hokkaido University, 3-1-1 Minato-cho, Hakodate, Hokkaido 041-8611, JapanJapan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka, Kanagawa 237-0061, JapanThe advection of warm Pacific water and the reduction in sea ice in the western Arctic Ocean may influence the abundance and distribution of copepods, a key component of food webs. To quantify the factors affecting the abundance of copepods in the northern Bering and Chukchi seas, we constructed habitat models explaining the spatial patterns of large and small Arctic and Pacific copepods separately. Copepods were sampled using NORPAC (North Pacific Standard) nets. The structures of water masses indexed by principle component analysis scores, satellite-derived timing of sea ice retreat, bottom depth and chlorophyll <i>a</i> concentration were integrated into generalized additive models as explanatory variables. The adequate models for all copepods exhibited clear continuous relationships between the abundance of copepods and the indexed water masses. Large Arctic copepods were abundant at stations where the bottom layer was saline; however they were scarce at stations where warm fresh water formed the upper layer. Small Arctic copepods were abundant at stations where the upper layer was warm and saline and the bottom layer was cold and highly saline. In contrast, Pacific copepods were abundant at stations where the Pacific-origin water mass was predominant (i.e. a warm, saline upper layer and saline and a highly saline bottom layer). All copepod groups showed a positive relationship with early sea ice retreat. Early sea ice retreat has been reported to initiate spring blooms in open water, allowing copepods to utilize more food while maintaining their high activity in warm water without sea ice and cold water. This finding indicates that early sea ice retreat has positive effects on the abundance of all copepod groups in the northern Bering and Chukchi seas, suggesting a change from a pelagic–benthic-type ecosystem to a pelagic–pelagic type.http://www.biogeosciences.net/13/4555/2016/bg-13-4555-2016.pdf
spellingShingle H. Sasaki
K. Matsuno
A. Fujiwara
M. Onuka
A. Yamaguchi
H. Ueno
Y. Watanuki
T. Kikuchi
Distribution of Arctic and Pacific copepods and their habitat in the northern Bering and Chukchi seas
Biogeosciences
title Distribution of Arctic and Pacific copepods and their habitat in the northern Bering and Chukchi seas
title_full Distribution of Arctic and Pacific copepods and their habitat in the northern Bering and Chukchi seas
title_fullStr Distribution of Arctic and Pacific copepods and their habitat in the northern Bering and Chukchi seas
title_full_unstemmed Distribution of Arctic and Pacific copepods and their habitat in the northern Bering and Chukchi seas
title_short Distribution of Arctic and Pacific copepods and their habitat in the northern Bering and Chukchi seas
title_sort distribution of arctic and pacific copepods and their habitat in the northern bering and chukchi seas
url http://www.biogeosciences.net/13/4555/2016/bg-13-4555-2016.pdf
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