Journal of the Marine Biological Association of India

Good Environment Management of cage farming using a coupled 3D hydrodynamic particle tracking model - A case study from Pizhala, Cochin, India

Volume 62 Issue 1

Sebin John, K. R. Muraleedharan1, C. Revichandran, Vineetha Valsalan, V. Kripa, S. Abdul Azeez, G. Seena and Ravi Kumar C. Nair

doi:10.6024/jmbai.2020.62.1.2169-14

Abstract

Hydrographic conditions such as water level, velocity, adequate water circulation and stratifications have a strong influence on the management of fish cage culture in the estuarine environment. In this study, a 3D hydrodynamic model was used to identify the areas of the mixed and stratified water column and to use this in conjunction with particle tracking models for appropriate site selection for cage culture. A Lagrangian method was used to simulate the instantaneous release of "particles" emulating discharge from fish cages to show the behaviour of waste in terms of water circulation and water exchange. Model simulation at Pizhala cage farm revealed that desirable water exchange is experienced in the monsoon and pre-monsoon period. There have existed strong spring-neap variability in the water level with an average range of 0.7 m with a speed of < 0.12 m/s in pre-monsoon and < 0.24 m/s in monsoon. This consistent flow patterns in the Pizhala region helps in the replenishment of oxygenated water and removal of waste produced beneath the cages, and it is corroborated by the Lagrangian particle transport model experiment coupled with Finite Volume Community Ocean Model (FVCOM) in the study.

Keywords

Cochin Estuary, hydrodynamics, modelling, aquaculture

Date : 30-07-2020