Variations in Apparent Oxygen Utilization and Effects of P Addition on Bacterial Respiration in Subtropical Hong Kong Waters
Author(s)
Yuan, Xiangcheng
Yin, Kedong
J. Harrison, Paul
He, Lei
Xu, Jie
Griffith University Author(s)
Year published
2011
Metadata
Show full item recordAbstract
Seven cruises during June 2005-November 2006 were conducted to study the variations in apparent oxygen utilization in Hong Kong coastal waters, and PO4 addition experiments were conducted in the summer to study bacterial responses to PO4 additions. Apparent oxygen utilization (AOU) was significantly correlated with PO4 concentrations. AOU was more responsive to PO4 when DIN/PO4 ratio was 50:1 in the summer wet season, and PO4 was more responsive to AOU in the dry season when N/P ratio was close to or less than 16:1, which suggested less regenerated PO4 during oxygen consumption in the former case than in the latter case. The ...
View more >Seven cruises during June 2005-November 2006 were conducted to study the variations in apparent oxygen utilization in Hong Kong coastal waters, and PO4 addition experiments were conducted in the summer to study bacterial responses to PO4 additions. Apparent oxygen utilization (AOU) was significantly correlated with PO4 concentrations. AOU was more responsive to PO4 when DIN/PO4 ratio was 50:1 in the summer wet season, and PO4 was more responsive to AOU in the dry season when N/P ratio was close to or less than 16:1, which suggested less regenerated PO4 during oxygen consumption in the former case than in the latter case. The PO4 addition experiment showed that 0.1 占PO4 addition increased bacterial respiration (BR) by 20 ᠴ%, but a 0.2-占PO4 addition saturated BR even when DIN/PO4 was 80:1, suggesting that there was a limit for PO4 stimulation of bacterial respiration. This finding of a 0.2-占PO4 saturation concentration for stimulating bacterial respiration is significant, and it also indicates that the release of PO4 during regeneration might be reduced by the same concentration.
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View more >Seven cruises during June 2005-November 2006 were conducted to study the variations in apparent oxygen utilization in Hong Kong coastal waters, and PO4 addition experiments were conducted in the summer to study bacterial responses to PO4 additions. Apparent oxygen utilization (AOU) was significantly correlated with PO4 concentrations. AOU was more responsive to PO4 when DIN/PO4 ratio was 50:1 in the summer wet season, and PO4 was more responsive to AOU in the dry season when N/P ratio was close to or less than 16:1, which suggested less regenerated PO4 during oxygen consumption in the former case than in the latter case. The PO4 addition experiment showed that 0.1 占PO4 addition increased bacterial respiration (BR) by 20 ᠴ%, but a 0.2-占PO4 addition saturated BR even when DIN/PO4 was 80:1, suggesting that there was a limit for PO4 stimulation of bacterial respiration. This finding of a 0.2-占PO4 saturation concentration for stimulating bacterial respiration is significant, and it also indicates that the release of PO4 during regeneration might be reduced by the same concentration.
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Journal Title
Estuaries and Coasts
Volume
34
Issue
3
Subject
Earth sciences
Environmental sciences
Biological sciences
Ecology not elsewhere classified