Gong
Gwo-Ching
Gong
Gwo-Ching
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ArticleEffect of the presence of virus-like particles on bacterial growth in sunlit xurface and dark deep ocean environments in the southern East China Sea(MDPI, 2021-10-19) Tsai, An-Yi ; Lin, Ying-Tsong ; Gong, Gwo-ChingVirus-like particles (VLPs) are thought to increase the dissolved organic carbon by releasing the contents of the host cell, which, in turn, can affect bacterial growth in natural aquatic environments. Yet, experimental tests have shown that the effect of VLPs on the bacterial growth rate at different depths has seldom been studied. Bacteria–VLP interaction and the effect of VLPs on bacterial growth rate in the sunlit surface (3 m) and dark, deep ocean (130 m) environments were first explored at a test site in the southern East China Sea of the northwest Pacific. Our experimental results indicated that bacterial and virus-like particle (VLP) abundance decreased with depth from 0.8 ± 0.3 × 105 cells mL−1 and 1.8 ± 0.4 × 106 VLPs mL−1 at 3 m to 0.4 ± 0.1 × 105 cells mL−1 and 1.4 ± 0.3 × 106 VLPs mL−1 at 130 m. We found that the abundance of VLPs to Bacteria Ratio (VBR) in the dark deep ocean (VBR = 35.0 ± 5.6) was higher than in the sunlit surface environment (VBR = 22.5 ± 2.1). The most interesting finding is that in the dark, deep ocean region the bacterial growth rate in the presence of VLPs was higher (0.05 h−1) than that in virus-diluted treatments (0.01 h−1). However, there was no significant difference in the bacterial growth rates between the treatments in the sunlit surface ocean region. Deep-sea ecosystems are dark and extreme environments that lack primary photosynthetic production, and our estimates imply that the contribution of recycled carbon by viral lysis is highly significant for bacterial growth in the dark, deep ocean environment. Further work for more study sites is needed to identify the relationship of VLPs and their hosts to enable us to understand the role of VLPs at different depths in the East China Sea.
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ArticleCorrigendum to “Nutrient supply in the Southern East China Sea after Typhoon Morakot”(Sears Foundation for Marine Research, 2013-11-01) Hung, Chin-Chang ; Chung, Chih-Ching ; Gong, Gwo-Ching ; Jan, Sen ; Tsai, Ya-Ling ; Chen, Kuo-Shu ; Chou, Wen Chen ; Lee, Ming-An ; Chang, Yi ; Chen, Meng-Hsien ; Yang, Wen-Rong ; Tseng, Chiung-Jung ; Gawarkiewicz, Glen G.
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ArticleNutrient supply in the Southern East China Sea after Typhoon Morakot(Sears Foundation for Marine Research, 2013-01-01) Hung, Chin-Chang ; Chung, Chih-Ching ; Gong, Gwo-Ching ; Jan, Sen ; Tsai, Ya-Ling ; Chen, Kuo-Shu ; Chou, Wen Chen ; Lee, Ming-An ; Chang, Yi ; Chen, Meng-Hsien ; Yang, Wen-Rong ; Tseng, Chiung-Jung ; Gawarkiewicz, Glen G.Recent studies show that typhoons have profound effects on phytoplankton assemblages along their tracks, but it is difficult to quantitatively estimate nutrient supply after a typhoon's passage due to a lack of nutrient information before and after the arrival of a typhoon. During the passage of Typhoon Morakot (July 22 to Aug. 26, 2009), we conducted pre- and post-typhoon field cruises to study nutrient supply in the Southern East China Sea (SECS). The results showed nitrate and phosphate supplies to the water column in the SECS after the typhoon's passage were 5.6 × 1011 g-N/day and 7.8 × 1010 g-P/day which were significantly higher than those before the typhoon occurred (nitrate supply = 1 × 109 g-N/day, phosphate supply = 1.6 × 108 g-P/day). We conclude from this data, and after consulting the available physical data, that the highest nitrate concentration was caused by strong upwelling and/or vertical mixing, and input of nutrient-replete terrestrial waters. The nitrate and phosphate input related to the passage of Typhoon Morakot can account for approximately 86% and 87% of summer nitrate and phosphate supplies to the southern East China Sea.