scholarly journals Free-living heterocystous cyanobacteria in the tropical marginal seas of the western North Pacific

2017 ◽  
Vol 39 (3) ◽  
pp. 404-422 ◽  
Author(s):  
Sing-How Tuo ◽  
Yuh-Ling Lee Chen ◽  
Houng-Yung Chen ◽  
Tien-Yi Chen
Keyword(s):  
North Pacific ◽  
Western North Pacific ◽  
Free Living ◽  
Heterocystous Cyanobacteria ◽  
Marginal Seas

scholarly journals Trichome Lengths of the Heterocystous N2-Fixing Cyanobacteria in the Tropical Marginal Seas of the Western North Pacific

2021 ◽  
Vol 8 ◽  
Author(s):  
Sing-how Tuo ◽  
Margaret R. Mulholland ◽  
Yukiko Taniuchi ◽  
Houng-Yung Chen ◽  
Wann-Neng Jane ◽  
...  
Keyword(s):  
North Pacific ◽  
Western North Pacific ◽  
Euphotic Zone ◽  
Nutrient Concentrations ◽  
Gas Vesicles ◽  
Filamentous Cyanobacteria ◽  
Cool Season ◽  
Free Living ◽  
Marginal Seas ◽  
Tropical Oceans

Calothrix rhizosoleniae and Richelia intracellularis are heterocystous cyanobacteria found in the tropical oceans. C. rhizosoleniae commonly live epiphytically on diatom genera Chaetoceros (C-C) and Bacteriastrum (B-C) while R. intracellularis live endosymbiotically within Rhizosolenia (R-R), Guinardia (G-R), and Hemiaulus (H-R); although, they occasionally live freely (FL-C and FL-R). Both species have much shorter trichomes than the other marine filamentous cyanobacteria such as Trichodesmium spp. and Anabaena gerdii. We investigated the trichome lengths of C. rhizosoleniae and R. intracellularis in the South China Sea (SCS) and the Philippine Sea (PS) between 2006 and 2014. On average, H-R had the shortest trichome lengths (3.5 cells/trichome), followed by B-C and C-C (4.9–5.2 cells/trichome) and FL-C (5.9 cells/trichome), and R-R, G-R, and FL-R had the longest trichome lengths (7.4–8.3 cells/trichome). Field results showed the trichome lengths of C-C and B-C did not vary seasonally or regionally. However, FL-C and H-R from the SCS and during the cool season had longer trichomes, where/when the ambient nutrient concentrations were higher. R-R, G-R, and FL-R also showed regional and seasonal variations in trichome length. Ultrastructural analysis found no gas vesicles within the C. rhizosoleniae cells to assist in buoyancy regulation. Results suggest that the trichome lengths of C. rhizosoleniae and R. intracellularis might be regulated by their diatom hosts’ symbiotic styles and by ambient nutrients. Short trichome length might help C. rhizosoleniae and R. intracellularis to stay in the euphotic zone regardless as to whether they are free-living or symbiotic.

Patterns in Rhizosolenia- and Guinardia-associated Richelia abundances in the tropical marginal seas of the western North Pacific

2021 ◽  
Author(s):  
Sing-How Tuo ◽  
Margaret R Mulholland ◽  
Yuh-Ling Lee Chen ◽  
P Dreux Chappell ◽  
Houng-Yung Chen
Keyword(s):  
North Pacific ◽  
Statistical Models ◽  
Western North Pacific ◽  
Distribution Patterns ◽  
Southwest Monsoon ◽  
Free Living ◽  
Multivariate Statistical ◽  
Marginal Seas ◽  
Key Factor ◽  
Time Periods

Abstract Richelia is a widespread, heterocystous, N2-fixing cyanobacterium that occurs in oligotrophic seas. It can be symbiotic within rhizosolenoid hosts, including Rhizosolenia (R-R) and Guinardia (G-R), and occasionally occurs as free-living (FL-R) filaments. We investigated the Richelia abundances in the South China (SCS) and Philippine Seas (PS) during the northeast (NEM) and southwest monsoon (SWM) seasons between 2001 and 2016. Field results showed that G-R was most abundant in the SCS during the SWM. Both R-R and FL-R were more abundant in the PS than the SCS and during the SWM versus the NEM. In general, R-R were more abundant than G-R, except at the SCS-SWM stations where abundances were comparable. Multivariate statistical models indicate that as R-R and G-R were abundant in warmer seawaters, nitrate plus nitrite was a key factor negatively controlling R-R abundance while silicate was more positively related to G-R. Positive correlation between G-R and FL-R abundances and microscopic observations imply that like Rhizosolenia-associated Richelia, filaments released from Guinardia hosts can remain viable outside their diatom hosts for time periods on the order of days. Overall, results reveal different distribution patterns between the two rhizosolenoid-Richelia symbioses and both G-R and R-R likely contribute to FL-R in the field.

Methane production in oxic seawater of the western North Pacific and its marginal seas

2020 ◽  
Vol 65 (10) ◽  
pp. 2352-2365
Author(s):  
Wang‐Wang Ye ◽  
Xiao‐Lei Wang ◽  
Xiao‐Hua Zhang ◽  
Gui‐Ling Zhang
Keyword(s):  
Methane Production ◽  
North Pacific ◽  
Western North Pacific ◽  
Marginal Seas

Stoichiometry of carbon, hydrogen, nitrogen, sulfur and oxygen in the particulate matter of the western North Pacific marginal seas

1996 ◽  
Vol 54 (1-2) ◽  
pp. 179-190 ◽  
Author(s):  
Chen-Tung Arthur Chen ◽  
Chi-Ming Lin ◽  
Being-Ta Huang ◽  
Lei-Fong Chang
Keyword(s):  
Particulate Matter ◽  
North Pacific ◽  
Western North Pacific ◽  
Marginal Seas

scholarly journals Biogeochemistry and ecosystems of continental margins in the western North Pacific Ocean and their interactions and responses to external forcing – an overview and synthesis

2014 ◽  
Vol 11 (23) ◽  
pp. 7061-7075 ◽  
Author(s):  
K.-K. Liu ◽  
C.-K. Kang ◽  
T. Kobari ◽  
H. Liu ◽  
C. Rabouille ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
Western North Pacific ◽  
North Pacific Ocean ◽  
Marine Ecosystems ◽  
Ecosystem Functions ◽  
Continental Margins ◽  
Special Issue ◽  
Western North Pacific Ocean ◽  
Marginal Seas

Abstract. In this special issue we examine the biogeochemical conditions and marine ecosystems in the major marginal seas of the western North Pacific Ocean, namely, the East China Sea, the Japan/East Sea to its north and the South China Sea to its south. They are all subject to strong climate forcing as well as anthropogenic impacts. On the one hand, continental margins in this region are bordered by the world's most densely populated coastal communities and receive tremendous amount of land-derived materials. On the other hand, the Kuroshio, the strong western boundary current of the North Pacific Ocean, which is modulated by climate oscillation, exerts strong influences over all three marginal seas. Because these continental margins sustain arguably some of the most productive marine ecosystems in the world, changes in these stressed ecosystems may threaten the livelihood of a large population of humans. This special issue reports the latest observations of the biogeochemical conditions and ecosystem functions in the three marginal seas. The studies exemplify the many faceted ecosystem functions and biogeochemical expressions, but they reveal only a few long-term trends mainly due to lack of sufficiently long records of well-designed observations. It is critical to develop and sustain time series observations in order to detect biogeochemical changes and ecosystem responses in continental margins and to attribute the causes for better management of the environment and resources in these marginal seas.

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