scholarly journals Ontogenetic vertical migration of the mesopelagic carnivorous copepod Paraeuchaeta spp. is related to their increase in body mass

2019 ◽  
Vol 41 (5) ◽  
pp. 791-797
Author(s):  
Atsushi Yamaguchi ◽  
Carin J Ashjian ◽  
Robert G Campbell ◽  
Yoshiyuki Abe
Keyword(s):  
Arctic Ocean ◽  
Body Mass ◽  
Vertical Migration ◽  
Migration Patterns ◽  
Habitat Depth ◽  
Mass Growth ◽  
Western Arctic Ocean ◽  
Western Subarctic Pacific ◽  
Western Arctic ◽  
Early Developmental

Abstract Two dominant mesopelagic carnivorous Paraeuchaeta copepods, Paraeuchaeta glacialis in the western Arctic Ocean and Paraeuchaeta elongata in the western subarctic Pacific, exhibited specialized ontogenetic vertical migration patterns with deeper occurrences of early copepodids (C1) and adults (C6F/M) and shallower occurrences of older copepodids C3−C5. Molt increments in body masses (wet, dry and ash-free dry masses) exhibited highly significant negative correlations with habitat depth. These facts suggest that both Paraeuchaeta species spend their reproductive (C6F/M) and early developmental (C1) stages in deeper layers to avoid predation and migrate upwards to where prey is abundant during the middle-late copepodid stages (C3−C5) to achieve greater mass growth.

scholarly journals N2O dynamics in the western Arctic Ocean during the summer of 2017

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jang-Mu Heo ◽  
Seong-Su Kim ◽  
Sung-Ho Kang ◽  
Eun Jin Yang ◽  
Ki-Tae Park ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Environmental Changes ◽  
Chukchi Sea ◽  
Hot Spot ◽  
Open Water ◽  
Northern Region ◽  
The Arctic ◽  
Western Arctic Ocean ◽  
Deep Layers ◽  
Western Arctic

AbstractThe western Arctic Ocean (WAO) has experienced increased heat transport into the region, sea-ice reduction, and changes to the WAO nitrous oxide (N2O) cycles from greenhouse gases. We investigated WAO N2O dynamics through an intensive and precise N2O survey during the open-water season of summer 2017. The effects of physical processes (i.e., solubility and advection) were dominant in both the surface (0–50 m) and deep layers (200–2200 m) of the northern Chukchi Sea with an under-saturation of N2O. By contrast, both the surface layer (0–50 m) of the southern Chukchi Sea and the intermediate (50–200 m) layer of the northern Chukchi Sea were significantly influenced by biogeochemically derived N2O production (i.e., through nitrification), with N2O over-saturation. During summer 2017, the southern region acted as a source of atmospheric N2O (mean: + 2.3 ± 2.7 μmol N2O m−2 day−1), whereas the northern region acted as a sink (mean − 1.3 ± 1.5 μmol N2O m−2 day−1). If Arctic environmental changes continue to accelerate and consequently drive the productivity of the Arctic Ocean, the WAO may become a N2O “hot spot”, and therefore, a key region requiring continued observations to both understand N2O dynamics and possibly predict their future changes.

Mesozooplankton prey preference and grazing impact in the western Arctic Ocean

2009 ◽  
Vol 56 (17) ◽  
pp. 1274-1289 ◽  
Author(s):  
Robert G. Campbell ◽  
Evelyn B. Sherr ◽  
Carin J. Ashjian ◽  
Stéphane Plourde ◽  
Barry F. Sherr ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Prey Preference ◽  
Grazing Impact ◽  
Western Arctic Ocean ◽  
Western Arctic

scholarly journals Sedimentary proxies for Pacific water inflow through the Herald Canyon, western Arctic Ocean

arktos ◽  
2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Henrik Swärd ◽  
Matt O’Regan ◽  
Christof Pearce ◽  
Igor Semiletov ◽  
Christian Stranne ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Water Inflow ◽  
Pacific Water ◽  
Western Arctic Ocean ◽  
Western Arctic

scholarly journals Timing of sea ice retreat can alter phytoplankton community structure in the western Arctic Ocean

2014 ◽  
Vol 11 (7) ◽  
pp. 1705-1716 ◽  
Author(s):  
A. Fujiwara ◽  
T. Hirawake ◽  
K. Suzuki ◽  
I. Imai ◽  
S.-I. Saitoh
Keyword(s):  
Community Structure ◽  
Sea Ice ◽  
Arctic Ocean ◽  
Phytoplankton Community ◽  
Phytoplankton Community Structure ◽  
Western Arctic Ocean ◽  
Phytoplankton Communities ◽  
Ice Retreat ◽  
Western Arctic ◽  
Sea Ice Retreat

Abstract. This study assesses the response of phytoplankton assemblages to recent climate change, especially with regard to the shrinking of sea ice in the northern Chukchi Sea of the western Arctic Ocean. Distribution patterns of phytoplankton groups in the late summers of 2008–2010 were analysed based on HPLC pigment signatures and, the following four major algal groups were inferred via multiple regression and cluster analyses: prasinophytes, diatoms, haptophytes and dinoflagellates. A remarkable interannual difference in the distribution pattern of the groups was found in the northern basin area. Haptophytes dominated and dispersed widely in warm surface waters in 2008, whereas prasinophytes dominated in cold water in 2009 and 2010. A difference in the onset date of sea ice retreat was evident among years–the sea ice retreat in 2008 was 1–2 months earlier than in 2009 and 2010. The spatial distribution of early sea ice retreat matched the areas in which a shift in algal community composition was observed. Steel-Dwass's multiple comparison tests were used to assess the physical, chemical and biological parameters of the four clusters. We found a statistically significant difference in temperature between the haptophyte-dominated cluster and the other clusters, suggesting that the change in the phytoplankton communities was related to the earlier sea ice retreat in 2008 and the corollary increase in sea surface temperatures. Longer periods of open water during the summer, which are expected in the future, may affect food webs and biogeochemical cycles in the western Arctic due to shifts in phytoplankton community structure.

Sign in / Sign up

Export Citation Format

Share Document