TY - JOUR
T1 - Dual character of Sundarban estuary as a source and sink of CO2 during summer
T2 - An investigation of spatial dynamics
AU - Akhand, Anirban
AU - Chanda, Abhra
AU - Dutta, Sachinandan
AU - Manna, Sudip
AU - Sanyal, Pranabes
AU - Hazra, Sugata
AU - Rao, K. H.
AU - Dadhwal, V. K.
N1 - Funding Information:
Acknowledgments Authors are grateful to Indian Institute of Remote Sensing and National Remote Sensing Centre, Department of Space, Government of India, for funding the research work. Abhra Chanda is thankful to Department of Science and Technology, Government of India for providing DST-INSPIRE fellowship. The anonymous reviewers are humbly acknowledged for their valuable suggestions and recommendations to improve the quality of the paper.
PY - 2013/8
Y1 - 2013/8
N2 - A comprehensive attempt has been made to evaluate the diurnal and spatial pattern of CO2 exchange between the atmosphere and water along the estuarine track of Indian Sundarbans during the two summer months, April and May, 2011. Rigorous field observations were carried out which included the hourly measurements of total alkalinity, pH, fugacity of CO2 in ambient air and water surface, dissolved oxygen, and chlorophyll a. The estuarine water was found rich in total alkalinity and was oversaturated with CO2 throughout the diurnal cycle in the two stations situated at the inner and middle estuary, respectively, whereas an entirely reverse situation was observed in the outer fringes. The fugacity of CO2 in water ranged from 152 to 657 μatm during the study period. The percentage of over-saturation in inner and middle estuary varied from 103 to 168 and 103 to 176 %, respectively, whereas the degree of under-saturation in the outer estuary lied between 40 and 99 %. Chlorophyll a concentrations were found higher in the outer estuary (12.3 ± 2.2 mg m-3) compared to the middle (6.4 ± 0.6 mg m-3) and inner parts (1.6 ± 0.2 mg m -3), followed by a similar decreasing pattern in nutrient availability from the outer to inner estuary. The sampling stations situated at the inner and middle estuary acted as a net source of 29.69 and 23.62 mg CO 2 m-2 day-1, respectively, whereas the outer station behaved as a net sink of -33.37 mg CO2 m-2 day-1. The study of primary production and community respiration further supports the heterotrophic nature of the estuary in the inner region while the outer periphery was marked by dominant autotrophic character. These contrasting results are in parity with the source characters of many inner estuaries and sinking characters of the outer estuaries situated at the distal continental shelf areas.
AB - A comprehensive attempt has been made to evaluate the diurnal and spatial pattern of CO2 exchange between the atmosphere and water along the estuarine track of Indian Sundarbans during the two summer months, April and May, 2011. Rigorous field observations were carried out which included the hourly measurements of total alkalinity, pH, fugacity of CO2 in ambient air and water surface, dissolved oxygen, and chlorophyll a. The estuarine water was found rich in total alkalinity and was oversaturated with CO2 throughout the diurnal cycle in the two stations situated at the inner and middle estuary, respectively, whereas an entirely reverse situation was observed in the outer fringes. The fugacity of CO2 in water ranged from 152 to 657 μatm during the study period. The percentage of over-saturation in inner and middle estuary varied from 103 to 168 and 103 to 176 %, respectively, whereas the degree of under-saturation in the outer estuary lied between 40 and 99 %. Chlorophyll a concentrations were found higher in the outer estuary (12.3 ± 2.2 mg m-3) compared to the middle (6.4 ± 0.6 mg m-3) and inner parts (1.6 ± 0.2 mg m -3), followed by a similar decreasing pattern in nutrient availability from the outer to inner estuary. The sampling stations situated at the inner and middle estuary acted as a net source of 29.69 and 23.62 mg CO 2 m-2 day-1, respectively, whereas the outer station behaved as a net sink of -33.37 mg CO2 m-2 day-1. The study of primary production and community respiration further supports the heterotrophic nature of the estuary in the inner region while the outer periphery was marked by dominant autotrophic character. These contrasting results are in parity with the source characters of many inner estuaries and sinking characters of the outer estuaries situated at the distal continental shelf areas.
KW - Air-water CO flux
KW - Autotrophy
KW - Diurnal variation
KW - Estuary
KW - Heterotrophy
KW - Mangrove environment
KW - Spatial variation
KW - Sundarban
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U2 - 10.1007/s10661-012-3042-x
DO - 10.1007/s10661-012-3042-x
M3 - Article
C2 - 23264059
AN - SCOPUS:84879841902
SN - 0167-6369
VL - 185
SP - 6505
EP - 6515
JO - Environmental Monitoring and Assessment
JF - Environmental Monitoring and Assessment
IS - 8
ER -