scholarly journals Spatial variations in zooplankton community structure along the Japanese coastline in the Japan Sea: influence of the coastal current

Ocean Science ◽  
2018 ◽  
Vol 14 (3) ◽  
pp. 355-369 ◽  
Author(s):  
Taketoshi Kodama ◽  
Taku Wagawa ◽  
Naoki Iguchi ◽  
Yoshitake Takada ◽  
Takashi Takahashi ◽  
...  
Keyword(s):  
Community Structure ◽  
Zooplankton Community ◽  
Japan Sea ◽  
Spatial Variations ◽  
The West ◽  
Zooplankton Community Structure ◽  
Japanese Coast ◽  
Toyama Bay ◽  
The Japan Sea ◽  
Water Species

Abstract. This study evaluates spatial variations in zooplankton community structure and potential controlling factors along the Japanese coast under the influence of the coastal branch of the Tsushima Warm Current (CBTWC). Variations in the density of morphologically identified zooplankton in the surface layer in May were investigated for a 15-year period. The density of zooplankton (individuals per cubic meter) varied between sampling stations, but there was no consistent west–east trend. Instead, there were different zooplankton community structures in the west and east, with that in Toyama Bay particularly distinct: Corycaeus affinis and Calanus sinicus were dominant in the west and Oithona atlantica was dominant in Toyama Bay. Distance-based redundancy analysis (db-RDA) was used to characterize the variation in zooplankton community structure, and four axes (RD1–4) provided significant explanation. RD2–4 only explained < 4.8 % of variation in the zooplankton community and did not show significant spatial difference; however, RD1, which explained 89.9 % of variation, did vary spatially. Positive and negative species scores on RD1 represent warm- and cold-water species, respectively, and their variation was mainly explained by water column mean temperature, and it is considered to vary spatially with the CBTWC. The CBTWC intrusion to the cold Toyama Bay is weak and occasional due to the submarine canyon structure of the bay. Therefore, the varying bathymetric characteristics along the Japanese coast of the Japan Sea generate the spatial variation in zooplankton community structure, and dominance of warm-water species can be considered an indicator of the CBTWC.

scholarly journals Spatial variations in zooplankton community structure along the Japanese coastline in the Japan Sea: influence of the coastal current

2017 ◽  
Author(s):  
Taketoshi Kodama ◽  
Taku Wagawa ◽  
Naoki Iguchi ◽  
Yoshitake Takada ◽  
Takashi Takahashi ◽  
...  
Keyword(s):  
Community Structure ◽  
Zooplankton Community ◽  
Japan Sea ◽  
Spatial Variations ◽  
Coastal Current ◽  
The West ◽  
Zooplankton Community Structure ◽  
Japanese Coast ◽  
Toyama Bay ◽  
The Japan Sea

Abstract. This study evaluates spatial variations in zooplankton community structure and potential controlling factors along the Japanese coast under the influence of the coastal branch of the Tsushima Warm Current (CBTWC). Variations in the density of morphologically-identified zooplankton in the surface layer in May were investigated for a 15-year period. The density of zooplankton (individuals per cubic meter) varied between sampling stations, but there was no consistent west–east trend. Instead, there were different zooplankton community structures in the west and east, with that in Toyama Bay particularly distinct: Corycaeus affinis and Calanus sinicus were dominant in the west and Oithona atlantica was dominant in Toyama Bay. Distance-based redundancy analysis (db-RDA) was used to characterize the variation in zooplankton community structure, and four axes (RD1–4) provided significant explanation. RD2–4 only explained

scholarly journals Deep current structure in the Toyama Deep-Sea Channel in the Japan Sea

2021 ◽  
Author(s):  
Tomoharu Senjyu
Keyword(s):  
Deep Sea ◽  
Water Mass ◽  
Current System ◽  
Japan Sea ◽  
East Side ◽  
The West ◽  
West Side ◽  
Side Slope ◽  
Toyama Bay ◽  
The Japan Sea

AbstractThe flow field in the Toyama Deep-Sea Channel (TDSC) in the Japan Sea was investigated based on mooring observations. An asymmetric current system accompanying offshore and onshore currents over the east- and west-side slopes in the channel, respectively, is suggested. A bottom intensified flow characteristic was observed at the offshore stations in the Yamato Basin. The asymmetric current system in the channel is also suggested by the asymmetric distribution of water characteristics across the TDSC in Toyama Bay; a cold dense water mass with higher dissolved oxygen (DO) and higher transmittance (Tr) was found over the west-side slope of the channel, whereas a water mass with lower DO and lower Tr was distributed over the east-side slope, suggesting a turbidity current from the head of Toyama Bay. The currents facing the shallower depth on their right-hand-side, along with the density distribution in the TDSC, suggest a density current system under the influence of the earth’s rotation. The dissolved oxygen concentration in the TDSC was significantly lower than that in the offshore region of the same temperature range. This suggests that the water mass over the west-side slope in the TDSC is a modified offshore water mass which experienced significant mixing with the low DO water mass over the east-side slope in the TDSC, probably due to strong shear between the offshore and onshore currents in the narrow channel.

THE STUDY ON THE EFFECT OF ELODEA NUTTALLII TO ZOOPLANKTON COMMUNITY STRUCTURE

2009 ◽  
Vol 33 (3) ◽  
pp. 556-561
Author(s):  
Gui-Jun YANG ◽  
Bo-Qiang QIN ◽  
Guang GAO ◽  
Xiao-Dong WANG ◽  
Hong-Yan WANG
Keyword(s):  
Community Structure ◽  
Zooplankton Community ◽  
Elodea Nuttallii ◽  
Zooplankton Community Structure

Crustacean zooplankton community structure in temporary and permanent grassland ponds

Hydrobiologia ◽  
2009 ◽  
Vol 632 (1) ◽  
pp. 225-233 ◽  
Author(s):  
S. Matthew Drenner ◽  
Stanley I. Dodson ◽  
Ray W. Drenner ◽  
John E. Pinder III
Keyword(s):  
Community Structure ◽  
Zooplankton Community ◽  
Crustacean Zooplankton ◽  
Zooplankton Community Structure ◽  
Permanent Grassland

scholarly journals Interaction between simulated dense Scenedesmus dimorphus (Chlorophyta) bloom and freshwater meta-zooplankton community

2018 ◽  
Vol 77 (2) ◽  
Author(s):  
Zengling Ma ◽  
Hengguo Yu ◽  
Ronald Thring ◽  
Chuanjun Dai ◽  
Anglv Shen ◽  
...  
Keyword(s):  
Community Structure ◽  
Green Algae ◽  
Aquatic Ecosystems ◽  
Algal Blooms ◽  
Algal Bloom ◽  
Photochemical Efficiency ◽  
Zooplankton Community ◽  
Post Inoculation ◽  
Zooplankton Community Structure ◽  
Scenedesmus Dimorphus

Algal bloom has been a subject of much research, especially the occurrence of blue-green algae (cyanobacteria) blooms and their effects on aquatic ecosystems. However, the interaction between green algae blooms and zooplankton community was rarely investigated. In the present study, the effects exerted by Scenedesmus dimorphus (green alga) bloom on the community structure of zooplankton and the top-down control of the bloom process mediated by the zooplankton were evaluated using a series of laboratory cultures. The results showed that a dense S. dimorphus bloom could change the zooplankton community structure by decreasing its diversity indices, leading to the enrichment of a particular zooplankton species, Brachionus calyciflorus. In the presence of mixed species of zooplankton, the density of S. dimorphus in the culture was decreased as determined by a change in total chlorophyll a (Chl a) concentration, which was about 200 μg L-1 lower than that of the zooplankton-free culture. Furthermore, the number of species belonging to Cladocera, Copepoda and Rotifera all decreased, with all the cladocerans disappeared in the co-culture within 2 weeks of culturing, while the density of rotifers increased from 818 (±243) ind L-1 at the time of inoculation to 40733 (±2173) ind L-1 on the 14th day post-inoculation. Grazing of S. dimorphus by the rotifer B. calyciflorus neutralized its growth, and the gradual increase in B. calyciflorus density eventually led to the collapse of the bloom. Furthermore, grazing by B. calyciflorus also led to a decrease in the maximal photochemical efficiency (Fv/Fm) of photosystem II (PSII). The combined changes occurring in the zooplankton community structure during the process of S. dimorphus bloom and the negative effects of grazing on algal growth, morphology and photosynthetic activities confirmed the key role of zooplankton in the control of algal bloom. The results of the study therefore indicated that dense algal blooms caused by non-toxic algae could still remain a threat to aquatic ecosystems.

Sign in / Sign up

Export Citation Format

Share Document