Management Strategies for Nile Tilapia (Oreochromis niloticus) Hatchery in the Face of Climate Change Induced Rising Temperature

Abstract

In the quest for appropriate management strategies for less egg production in Nile tilapia (Oreochromis niloticus) due to climate change induced increasing temperature, five treatments (T): shade with cloth over brood hapa (T1), increase in pond depth (T2), aeration (T3), combination of above three interventions (T4) and control (no intervention) (T5) were investigated in a commercial hatchery in Mymensingh, Bangladesh during April to September. Mean egg production in T1, T2, T3, T4 and T5 was 20488, 15369, 3596, 21021 and 3979 eggs/hapa, respectively. T1 was the best strategy considered due to efficiency and simplicity. In May T1, T2, T3, T4 and T5 produced highest 30859, 36119, 8997, 45876 and 5506 eggs/hapa at 29.69°C, 30.12°C, 29.96°C, 29.61°C, and 31.26°C temperature, respectively. The most suitable water temperature for highest egg production (20365 eggs/hapa) was 29-31°C. Egg production above 32°C was found to be very low (179 eggs/hapa). Suitable ranges of dissolved oxygen, pH, alkalinity, ammonia and turbidity for egg production were found to be 4.5-6.0 mg/L, 8.0-8.8, 105-150 mg/L, 0-0.5 mg/L and 15-35 cm, respectively. In high temperature months commercial fish hatcheries should use shed with cloth over brood hapa to produce higher amount eggs.