The productivity phenomenon of tilapia floating net cages in Jatiluhur Reservoir in line with the Citarum Harum program

The research was conducted to determine the productivity conditions of tilapia cultivation in the field along with the implementation of reducing the number of floating net cages. Production observations of tilapia culture were carried out on net cages owned by fish farmer in the Jatiluhur Reservoir from 2012 to 2019. The first period-P1 (2013-2015) was before the reduction in the number of net cages, the culture used a double net system and hybrid system. The second period-P2 (2016-2019) when the program started, KJA culture was carried out with a self-maintenance system (100% feeding for tilapia). The value of fish harvest weight ranged from 96.39-102.47 g (P1) and 196.84-278.33 g (P2). The range of survival rate is between 56.99–78.79% (P1), and 60.92–80.41% (P2). The feed efficiency value obtained in the P2 period was 75.77–86.34% while for P1 it was not defined because it was not a 100% feed system (independent). The daily weight gain, productivity and multiple values were as follows: 0.58-1.0 g/day, 0.14-0.45 g/m2, and 2.35-4.56x (P1); 1.43–3.00 g/day, 1.92–2.89 kg/m2 and 6.77–10.80x (P2). The monitored water quality parameters were still within a tolerable range for tilapia floating net cage culture.