scholarly journals High-Resolution Vertical Observations of Phytoplankton Groups Derived From an in-situ Fluorometer in the East China Sea and Tsushima Strait

2022 ◽  
Vol 8 ◽  
Author(s):  
Qian Xu ◽  
Shengqiang Wang ◽  
Chiho Sukigara ◽  
Joaquim I. Goes ◽  
Helga do Rosario Gomes ◽  
...  
Keyword(s):  
High Resolution ◽  
Water Column ◽  
East China Sea ◽  
Green Algae ◽  
Brown Algae ◽  
East China ◽  
The East China Sea ◽  
China Sea ◽  
Tsushima Strait

Vertical distribution of phytoplankton composition in the East China Sea (ECS) and Tsushima Strait (TS) was highly variable in the region where the Changjiang River diluted water (CDW), Kuroshio water (KW), and Tsushima water (TW) intersected. An in-situ multiple excitation fluorometer was used to obtain the high-resolution phytoplankton groups data from every meter of the water column. Sharp differences were noted in the distribution of phytoplankton groups in the CDW, KW, and TW. In the CDW, brown algae were generally present ~60% of all depths with exception of subsurface chlorophyll-a maximum (SCM), whereas cyanobacteria (>40%) and green algae plus cryptophytes (>40%) were found above and below the SCM, respectively. In TW, where chlorophyll a (CHL) was lower than in the CDW, brown algae predominated the water column (>60%) and SCM (>80%), except the surface layer where cyanobacteria dominated. In KW, a high fraction of cyanobacteria (>40%) extended up to 40 m, while brown and green algae dominated (>60%) the deeper waters below 40 m at western and eastern stations, respectively. These results can be further related to water property and nutrient concentration of the water masses in each region. This new data show that the in-situ multiple excitation fluorometer can be a powerful tool to estimate high-resolution vertical profiles of phytoplankton groups on a large scale in marine environments.

scholarly journals Responses of lower trophic-level organisms to typhoon passage on the outer shelf of the East China Sea: an incubation experiment

2013 ◽  
Vol 10 (4) ◽  
pp. 6605-6635 ◽  
Author(s):  
N. Yasuki ◽  
K. Suzuki ◽  
A. Tsuda
Keyword(s):  
Water Column ◽  
East China Sea ◽  
Trophic Level ◽  
Outer Shelf ◽  
East China ◽  
Strong Wind ◽  
The East China Sea ◽  
Phytoplankton Productivity ◽  
China Sea ◽  
Lower Trophic Level

Abstract. Typhoons can induce vertical mixing, upwelling, or both in the water column due to strong wind stress. These events can induce phytoplankton blooms in the oligotrophic ocean after typhoon passage. However, little is known about the responses of lower trophic-level organisms or changes in the community structure following the passage of typhoons, particularly in offshore regions. Therefore, we evaluated community succession on the outer shelf of the East China Sea through on-deck bottle incubation experiments simulating hydrographic conditions after the passage of a typhoon. Under all of the experimental conditions we tested, chlorophyll a concentrations increased more than 9-fold within 6 days, and these algal cells were mainly composed of large diatoms (>10 μm). Ciliates also increased along with the diatom bloom. These results suggest that increases in diatom and ciliate populations may enhance biogenic carbon export in the water column. Typhoons can affect not only phytoplankton productivity, but also the composition of lower trophic-level organisms and biogeochemical processes in oligotrophic offshore regions.

scholarly journals Effectiveness of stocking Sparus macrocephalus fry in situ in the East China Sea

2019 ◽  
Vol 4 (2) ◽  
pp. 74-79
Author(s):  
Qingsong Hu ◽  
Ning Bao ◽  
Hafiz Abdur Rahman ◽  
Yazhou Jiang ◽  
Shouyu Zhang ◽  
...  
Keyword(s):  
East China Sea ◽  
East China ◽  
The East China Sea ◽  
China Sea ◽  
Sparus Macrocephalus

scholarly journals Cross-shelf water exchange in the East China Sea as estimated by satellite altimetry and in situ hydrographic measurement

2016 ◽  
Vol 121 (9) ◽  
pp. 7192-7211 ◽  
Author(s):  
Ruibin Ding ◽  
Daji Huang ◽  
Jiliang Xuan ◽  
Bernhard Mayer ◽  
Feng Zhou ◽  
...  
Keyword(s):  
East China Sea ◽  
Satellite Altimetry ◽  
Water Exchange ◽  
East China ◽  
Shelf Water ◽  
The East China Sea ◽  
China Sea

scholarly journals Retrieving monthly and interannual pH<sub>T</sub> on the East China Sea shelf using an artificial neural network: ANN-pH<sub>T</sub>-v1

2019 ◽  
Author(s):  
Xiaoshuang Li ◽  
Richard Bellerby ◽  
Jianzhong Ge ◽  
Philip Wallhead ◽  
Jing Liu ◽  
...  
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Water Column ◽  
East China Sea ◽  
East China ◽  
Ann Model ◽  
The East China Sea ◽  
China Sea ◽  
Artificial Neural ◽  
Artificial Neural Network Ann

Abstract. While our understanding of pH dynamics has strongly progressed for open ocean regions, for marginal seas such as the East China Sea (ECS) progress has been constrained by limited observations and complex interactions between biological, physical, and chemical processes. Seawater pH is a very valuable oceanographic variable but not always measured using high quality instrumentation and according to standard practices. In order to predict water column total scale pH (pHT) and enhance our understanding of the seasonal variability of pHT on the ECS shelf, an artificial neural network (ANN) model was developed using 11 cruise datasets from 2013 to 2017 with coincident observations of pHT, temperature (T), salinity (S), dissolved oxygen (DO), nitrate (N), phosphate (P) and silicate (Si) together with sampling position and time. The reliability of the ANN model was evaluated using independent observations from 3 cruises in 2018, and showed a root mean square error accuracy of 0.04. A weight analysis of the ANN model variables suggested that DO, S, T were the most important predictor variables. Monthly water column pHT for the period 2000-2016 was retrieved using T, S, DO, N, P, and Si from the Changjiang Biology Finite-Volume Coastal Ocean Model (FVCOM).

Sign in / Sign up

Export Citation Format

Share Document