Risk of Climate Variability on Tilapia Cage Culture in Songkhram River in Northeastern Thailand

Abstract

The cage culture of Nile Tilapia in the river is one of the most important methods for Nile Tilapia (Oreochromis niloticus) farming in Thailand. Songkhram river is a significant river in north-eastern Thailand where Nile Tilapia river-based cage culture has been applied widely. However, river-based cage culture is an open culturing system where farmers do not fully control weather and water quality. This study investigates the risks of climate variability on Nile Tilapia in riv-er-based cage culture. This study recommends strategies to reduce fish yield losses. The samples of this study are the Nile Tilapia river-based cage culture farmers along the Songkhram river in 5 districts in Sakon Nakhon and Nakhon Phanom, including Thauthen, Khamtakla, Akatamnuai, Sisongkhram and Nathom. This study applies a simple random sampling method. We used structured questionnaires to collect the data from 148 fish farmers between April and December 2017. Hot weather during March and April was perceived to be the most important factor causing fish diseases and led to losses (68.2 %). The other significant factors that led to fish death were drought (52.7 %) and flood (40.5 %). Flood typically takes place between June and August. Cold weather was perceived not to affect the fish losses (32.4 %). However, it did affect the growth rate. Cold weather typically takes place between December and February. Re-garding the hot weather, fish farmers applied preventive measures such as mon-itoring and surveillance, stopping or delaying stocking schedules. For drought, the fish farmers relocated the cages towards the deeper water areas and used aerators to control water quality. Most farmers tie their cages securely during flooding season and relocate them closer to the bank. The fish farmers moni-tored their cages more closely than usual for the cold weather and postponed the stocking date. The study of risks and loss mitigation from climate variabilities in this research will be helpful for strategic aquaculture planning to cope with cli-mate variabilities in the future.