Table of Contents
Journal of Ecosystems
Volume 2014, Article ID 526245, 17 pages
http://dx.doi.org/10.1155/2014/526245
Research Article

Dynamics of Dissolved Oxygen in Relation to Saturation and Health of an Aquatic Body: A Case for Chilka Lagoon, India

1Fluid Dynamics Division, School of Advanced Sciences, VIT University, Vellore 632014, India
2Department of Mathematics, Andhra University, Visakhapatnam 530003, India
3Department of Basic Science & Humanities, GMR Institute of Technology, Rajam, Srikakulam 532127, India
4Marine Biological Laboratory, Department of Zoology, Andhra University, Visakhapatnam 530003, India
5Ecological Modelling Laboratory, Department of Zoology, Visva-Bharati University, Santiniketan 731235, India

Received 13 March 2013; Revised 4 December 2013; Accepted 5 December 2013; Published 20 February 2014

Academic Editor: Wen-Cheng Liu

Copyright © 2014 B. S. R. V. Prasad et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Dissolved oxygen (DO) is essential for an aquatic ecosystem since it controls the biological productivity. Here, we propose a unidimensional dynamic model for DO by incorporating biological (photosynthesis, respiration, and mineralization), physical (atmospheric reaeration) and chemical (nitrification) processes so characteristic of shallow coastal water bodies. The analytical study of the proposed model is focussed on supersaturation and undersaturation of oxygen in the water body. The controllability of the ecosystem health has also been investigated. Model results indicate that, while undersaturation of oxygen is largely governed by nitrification and Net Ecosystem Metabolism (NEM), the supersaturation is controlled by photosynthetic activity. The model results are corroborated with observed data collected from Chilka lagoon, India. Subsequently, a biogeochemical model to study the DO variations in Chilka lagoon has been constructed. The model is properly calibrated and validated with observed data. Two independent sets of data (2004-2005 and 2005-2006) were used for model calibration and validation and Chi-square tests supported its robustness ( and 0.987; ). The model was used to evaluate independently the influence of individual taxa (diatoms, microphytobenthos, and cyanophyceans) on DO variations. Simulations indicate the vital role of microphytobenthos in lagoon DO dynamics and the overall wellbeing.