A consistent structure of phytoplankton communities across the warm–cold regions of the water mass on a meridional transect in the East/Japan Sea

Kwak, Jin Ho; Han, Eunah; Lee, Sang‐Heon; Park, Hyun Je; Kim, Kyung‐Ryul; Kang, Chang‐Keun

doi:10.1016/j.dsr2.2017.07.001

Cited by 12 publications

(16 citation statements)

References 41 publications

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“…Observational and model studies on the impact of increasing small phytoplankton uptake suggest that primary productivity will decrease if small phytoplankton becomes the predominant species [24,[53][54][55][56]. Since our study did not include species identification and abundance, the discussion on species diversity is limited in this regard.…”

Section: Impact Of Small Phytoplankton On the Total Din Assimilation Ratesmentioning

confidence: 96%

The Contribution of Small Phytoplankton Communities to the Total Dissolved Inorganic Nitrogen Assimilation Rates in the East/Japan Sea: An Experimental Evaluation

Bhavya

Kang

Jang

et al. 2020

JMSE

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As a part of Korean-Russian joint expeditions in the East/Japan Sea during 2012 and 2015, a set of total and small (<2 μm) phytoplankton NO3− and NH4+ uptake rate estimations were carried out. The study aimed to assess the spatio-temporal variations in dissolved inorganic nitrogen (DIN) assimilation by the total and small phytoplankton. The results show that the total NO3− uptake rates during 2012 varied between 0.001 and 0.150 μmol NL−1h−1 (mean ± SD = 0.034 ± 0.033) and that the total NH4+ uptake rates ranged between 0.002 and 0.707 μmol NL−1h−1 (mean ± SD = 0.200 ± 0.158). The total uptake rates during 2015 were ranged from 0.003 to 0.530 (mean ± S.D. = 0.117 ± 0.120 μmol NL−1h−1) for NO3− and from 0.008 to 1.17 (mean ± S.D. = 0.199 ± 0.266 NL−1h−1) for NH4+. The small phytoplankton NO3− and NH4+ uptake rates during 2015 ranged between 0.001 and 0.164 (mean ± S.D. = 0.033 ± 0.036) μmol NL−1h−1 and 0.010–0.304 (mean ± S.D. = 0.101 ± 0.073) μmol NL−1h−1, respectively. Small phytoplankton’s contribution to the total depth-integrated NO3− and NH4+ uptake rates ranged from 10.24 to 59.36% and from 30.21 to 68.55%, respectively. The significant negative relationship observed between the depth-integrated total NO3− and NH4+ uptake rates and small phytoplankton contributions indicates a possible decline in the DIN assimilation rates under small phytoplankton dominance. The results from the present study highlight the possibility of a reduction in the total DIN assimilation process in the East/Japan Sea when small phytoplankton dominate under strong thermal stratification due to sea surface warming. The present study’s findings agree with the model projections, which suggested a decline in primary production in the global warming scenario.

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Section: Impact Of Small Phytoplankton On the Total Din Assimilation Ratesmentioning

confidence: 96%

The Contribution of Small Phytoplankton Communities to the Total Dissolved Inorganic Nitrogen Assimilation Rates in the East/Japan Sea: An Experimental Evaluation

Bhavya

Kang

Jang

et al. 2020

JMSE

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“…There are diverse species of phytoplankton in the EJS such as diatoms, cryptophytes, prymnesiophytes, dinoflagellates, cyanobacteria, and pelagophytes. During spring, the contributions of diatoms, prymnesiophytes, and cyanobacteria to the total amount of phytoplankton in this region amounted to 58 ± 19, 17, and 8 ± 6%, respectively (Kwak et al 2017). As one of the most dominant phytoplankton species, diatoms are reported to have a double timescale of several hours (Zeitzschel 1978;Kwak et al 2013Kwak et al , 2017.…”

Section: Physiological Aspect Of Chlorophyll-a Changesmentioning

confidence: 96%

Short-Term Response of Chlorophyll-a Concentration to Change in Sea Surface Wind Field over Mesoscale Eddy

Park

Kang

et al. 2019

Estuaries and Coasts

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Short-term biological responses to sea surface wind field over mesoscale eddies were investigated using hourly ocean color chlorophyll-a (chl-a) concentration data from the Geostationary Ocean Color Imager (GOCI), scatterometer wind data, and satellite sea surface temperature (SST) data. Four warm eddies were identified from SST fronts, by subjectively fitting ellipses to selected points, and anticyclonically rotating current vectors were estimated from sequential chl-a images. Scatterometer data confirmed wind speed strengthening by approximately 30% over anticyclonic eddies, regardless of wind direction, caused by stability changes in the marine atmospheric boundary layer. The modified wind speed field produced a characteristic pattern of wind stress curl and Ekman pumping (EKP) over the eddies, showing positive and negative values on the left and right sides of the upwind direction, respectively. The EKP field was divided into three components: eddy current-induced, relative vorticity gradient-induced, and crosswind SST-induced terms. Short-term changes in the chl-a concentration showed a positive relation with EKP variations over most eddies. SST-induced EKP played a significant role in the eddies for 76% of the total variations, which is much higher than that in other oceans. This study emphasizes the significant effect of SST distribution and the biological responses to changes in an EKP field in relation to air-sea interactions and feedback processes in the East Sea (Sea of Japan).

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“…Sample peaks were identified based on their retention time compared with those of pure standards. Further details on analysis, calibration, and quantification have been given elsewhere (Lee et al, 2011;Kwak et al, 2017).…”

Section: Sampling and Processingmentioning

confidence: 99%

Variability in copepod trophic levels and feeding selectivity based on stable isotope analysis in Gwangyang Bay of the southern coast of the Korean Peninsula

et al. 2018

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Abstract. Trophic preference (i.e., food resources and trophic levels) of different copepod groups was assessed along a salinity gradient in the temperate estuarine Gwangyang Bay of Korea, based on seasonal investigation of taxonomic results in 2015 and stable isotope analysis incorporating multiple linear regression models. The δ13C and δ15N values of copepods in the bay displayed significant spatial heterogeneity as well as seasonal variations, which were indicated by their significant relationships with salinity and temperature, respectively. Both spatial and temporal variations reflected those in isotopic values of food sources. The major calanoid groups (marine calanoids and brackish water calanoids) had a mean trophic level of 2.2 relative to nanoplankton as the basal food source, similar to the bulk copepod assemblage; however, they had dissimilar food sources based on the different δ13C values. Calanoid isotopic values indicated a mixture of different genera including species with high δ15N values (e.g., Labidocera, Sinocalanus, and Tortanus), moderate values (Calanus sinicus, Centropages, Paracalanus, and Acartia), and relatively low δ15N values (Eurytemora pacifica and Pseudodiaptomus). Feeding preferences of different copepods probably explain these seasonal and spatial patterns of the community trophic niche. Bayesian mixing model calculations based on source materials of two size fractions of particulate organic matter (nanoplankton at < 20 µm vs. microplankton at 20–200 µm) indicated that Acartia and Centropages preferred large particles; Paracalanus, Calanus, Eurytemora, and Pseudodiaptomus apparently preferred small particles. Tortanus was typically carnivorous with low selectivity on different copepods. Labidocera preferred marine calanoids Acartia, Centropages, and harpacticoids; on the other hand, Sinocalanus and Corycaeus preferred brackish calanoids Paracalanus and Pseudodiaptomus. Overall, our results depict a simple energy flow of the planktonic food web of Gwangyang Bay: from primary producers (nanoplankton) and a mixture of primary producers and herbivores (microplankton) through omnivores (Acartia, Calanus, Centropages, and Paracalanus) and detritivores (Pseudodiaptomus, Eurytemora, and harpacticoids) to carnivores (Corycaeus, Tortanus, Labidocera, and Sinocalanus).

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A consistent structure of phytoplankton communities across the warm–cold regions of the water mass on a meridional transect in the East/Japan Sea

Cited by 12 publications

References 41 publications

The Contribution of Small Phytoplankton Communities to the Total Dissolved Inorganic Nitrogen Assimilation Rates in the East/Japan Sea: An Experimental Evaluation

The Contribution of Small Phytoplankton Communities to the Total Dissolved Inorganic Nitrogen Assimilation Rates in the East/Japan Sea: An Experimental Evaluation

Short-Term Response of Chlorophyll-a Concentration to Change in Sea Surface Wind Field over Mesoscale Eddy

Variability in copepod trophic levels and feeding selectivity based on stable isotope analysis in Gwangyang Bay of the southern coast of the Korean Peninsula

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