Summer primary productivity and phytoplankton community composition driven by different hydrographic structures in the East/Japan Sea and the Western Subarctic Pacific

Kwak, Jin Ho; Lee, Sang‐Heon; Hwang, Jeomshik; Suh, Young-Sang; Park, Hyun Je; Chang, Kyung‐Il; Kim, Kyung‐Ryul; Kang, Chang‐Keun

doi:10.1002/2014jc009874

Cited by 38 publications

(33 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, Kwak et al (2014) measured a relatively high primary production rate (716 mg C m −2 d −1 ) even in the summer season (June-August), when phytoplankton are not normally actively growing at other temperate locations (Lee et al, 2017b). The value observed in summer by Kwak et al (2014) is comparable to the primary production rate observed during the spring bloom in this study (790 mg C m −2 d −1 ).…”

Section: Contributions Of Small and Large Phytoplankton To The Total supporting

confidence: 75%

Characteristics of Different Size Phytoplankton for Primary Production and Biochemical Compositions in the Western East/Japan Sea

et al. 2020

Self Cite

View full text Add to dashboard Cite

The current phytoplankton community structure is expected to change, with small phytoplankton becoming dominant under ongoing warming conditions. To understand and evaluate the ecological roles of small phytoplankton in terms of food quantity and quality, the carbon uptake rates and intracellular biochemical compositions (i.e., carbohydrates, CHO; proteins, PRT; and lipids, LIP) of phytoplankton of different sizes were analyzed and compared in two different regions of the western East/Japan Sea (EJS): the Ulleung Basin (UB) and northwestern East/Japan Sea (NES). The average carbon uptake rate by the whole phytoplankton community in the UB (79.0 ± 12.2 mg C m–2 h–1) was approximately two times higher than that in the NES (40.7 ± 2.2 mg C m–2 h–1), although the average chlorophyll a (chl a) concentration was similar between the UB (31.0 ± 8.4 mg chl a m–2) and NES (28.4 ± 7.9 mg chl a m–2). The main reasons for the large difference in the carbon uptake rates are believed to be water temperature, which affects metabolic activity and growth rate, and the difference in euphotic depths. The contributions of small phytoplankton to the total carbon uptake rate were not significantly different between the regions studied. However, the rate of decrease in the total carbon uptake with increasing contributions from small phytoplankton was substantially higher in the UB than in the NES. This result suggests that compared to other regions in the EJS, the primary production in the UB could decrease rapidly under ongoing climate change. The calorific contents calculated based on biochemical compositions were similar between the small (1.01 ± 0.33 Kcal m–3) and large (1.14 ± 0.36 Kcal m–3) phytoplankton in the UB, whereas the biochemical contents were higher in the large phytoplankton (1.88 ± 0.54 Kcal m–3) than in the small phytoplankton (1.06 ± 0.18 Kcal m–3) in the NES. The calorific values per unit of chl a were higher for the large phytoplankton than for the small phytoplankton in both regions, which suggests that large phytoplankton could provide a more energy efficient food source to organisms in higher trophic levels in the western EJS.

show abstract

Section: Contributions Of Small and Large Phytoplankton To The Total supporting

confidence: 75%

Characteristics of Different Size Phytoplankton for Primary Production and Biochemical Compositions in the Western East/Japan Sea

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…Periods of high primary and secondary productivity typically occur when microplankton are dominated by diatom blooms, while periods of low productivity are controlled by the microbial loop. Kwak et al (2014) reported that strong stratification with high temperature and/or low salinity was observed in the surface in summer in the East Sea. This caused a subsequent limitation in nutrient supply and the relatively low primary productivity in the surface mixed layer.…”

Section: Discussionmentioning

confidence: 99%

Evidence for ontogenetic feeding strategies in four calanoid copepods in the East Sea (Japan Sea) in summer, revealed by stable isotope analysis

Wi²,

Suh

2015

Ocean Sci. J.

View full text Add to dashboard Cite

 Deciphering the ontogenetic feeding ecology of copepods is essential to understanding their role in the energy transfer of marine ecosystems. We used stable isotope analysis to examine the ontogenetic feeding strategies of the four coexisting calanoid copepods, Mesocalanus tenuicornis, Metridia pacifica, Calanus sinicus, and Neocalanus plumchrus, in the East Sea (Japan Sea) in summer. Moreover, we used the stable carbon and nitrogen isotope composition of small-sized plankton in three cell size fractions, pico-(< 2 μm), nano-(2-20 μm) and microplankton (20-200 μm), to identify the dietary preference at each developmental stage. The relative carbon masses of pico-, nano-and microplankton were 18, 38, and 44%, respectively, and their δ 13 C and δ 15 N values gradually increased with increasing size classes. The ontogenetic trophic position of four copepods were relatively low and ranged from 2.1 to 2.6, indicating that herbivores feed on small-sized phytoplankton, pico-and nanoplankton. Among copepodid stages, the δ 13 C and δ 15 N values of M. tenuicornis and C. sinicus differed significantly, while those of M. pacifica and N. plumchrus were not significantly different. In M. tenuicornis, the smallest species among the four copepods examined, the diet preference of CIV for picoplankton changed to nanoplankton in the adult stage. When M. pacifica developed from CIV to adult, the diet preference changed from pico-to microplankton. The proportion of microplankton in the diet of C. sinicus and N. plumchrus increased from CIV to female adult and from CIII to CV, respectively. During the developmental progress in copepodid stages, the smaller copepods significantly changed their dietary preference from pico-to microplankton, while the larger copepods consistently fed on microplankton. We suggest that smaller copepods have an advantage in survival at early copepodid stages compared with larger copepods in summer when microplankton biomass is relatively low.

show abstract

“…Daily primary productivity (mg C m −3 d −1 ) was calculated by multiplying the measured hourly carbon uptake rate with photoperiod conversion factors (Kanda et al, 1985;Fan and Glibert, 2005). Integrated primary productivity (mg C m −2 d −1 ) was calculated using the trapezoidal rule for the entire euphotic zone (Kwak et al, 2014).…”

Section: Primary Productivity Measurementmentioning

confidence: 99%

Dominance of Autochthonous Phytoplankton-Derived Particulate Organic Matter in a Low-Turbidity Temperate Estuarine Embayment, Gwangyang Bay, Korea

et al. 2020

Self Cite

View full text Add to dashboard Cite

In estuaries, the sources of organic matter, its composition, and its functional role in the coastal ecosystem food web are all influenced by dominant estuarine processes. We investigated seasonal variations in the quantity and composition of dissolved inorganic nutrients, suspended particulate matter (SPM), and phytoplankton across a low-turbidity estuarine-coastal continuum in Gwangyang Bay, South Korea. The narrow estuarine channel has a sharp salinity gradient (from 0 to around 30) and low SPM concentrations (<20 mg L −1). The channel carries river discharge, with a large quantity of nutrients (NO 3 and SiO 2), into the bay. The especially low SPM concentrations in the estuary (range: 2.0-29.1 mg L −1), and generous nutrient source, create an exceptionally low-turbidity condition in the water column and high primary productivity with no conspicuous spatial or seasonal trends. Gradually increasing δ 13 C values, low POC:Chla (<200), and low molar C:N (4-8) in the SPM, together with higher Chla concentrations at low SPM locations along the longitudinal transect, suggest that local production of phytoplankton has a strong influence on the distributional patterns of particulate organic matter. Short water-residence times, within the bay system, impede the accumulation of diverseorigin organic matter. The community composition of phytoplankton, distinguished by their size group, also plays a role in characterizing SPM quantity and composition. The results indicate that autochthonous pelagic production governs biogeochemical features in the low-turbidity estuarine embayment, contrasting with a prevalence of allochthonous organic matter, and its active processing, in highly turbid and/or longer residence-time systems.

show abstract

Summer primary productivity and phytoplankton community composition driven by different hydrographic structures in the East/Japan Sea and the Western Subarctic Pacific

Cited by 38 publications

References 56 publications

Characteristics of Different Size Phytoplankton for Primary Production and Biochemical Compositions in the Western East/Japan Sea

Characteristics of Different Size Phytoplankton for Primary Production and Biochemical Compositions in the Western East/Japan Sea

Evidence for ontogenetic feeding strategies in four calanoid copepods in the East Sea (Japan Sea) in summer, revealed by stable isotope analysis

Dominance of Autochthonous Phytoplankton-Derived Particulate Organic Matter in a Low-Turbidity Temperate Estuarine Embayment, Gwangyang Bay, Korea

Contact Info

Product

Resources

About