Fish cutting waste as a resource: sustainable feed alternative for coastal aquaculture practices

Fish cutting waste (FCW) from retail markets remains underutilized. This study quantified FCW generation and utilisation practices across maritime zones of India, and evaluated its potential as a feed in coastal cage farming. Regional surveys showed strong variation in FCW generation: South east and North east zones dominated by units with <100 kg/day production, while more than 60% of units in the North west generated >500 kg/day. North east have poor to moderate quality FCW (p < 0.05), the South east by poor, the North west by consistent average, and the South west displaying poor to good quality. Integrated mapping indicated higher FCW utilisation in North west and South west, mainly for fish meal and fertilizer. Cage culture trials using silver pompano fingerlings revealed similar (p > 0.05) growth and survival between FCW-fed [34.5-35.0% crude protein (CP) and 13.19-13.21% crude lipid (CL)] and pellet-fed (38% CP and 7% CL) fish, with final weights of 47.08 ± 0.58 g and 45.12 ± 2.19 g, respectively after 60 days. Feed conversion ratio (FCR) was similar for FCW (2.43 ± 0.18) and pellets (2.49 ± 0.13). Carcass of FCW fed fish contained 55.30% CP and 12.34% CL, lower than the pellet fed fish (58.92% CP, 16.72% CL). With the same initial capital investment, the FCW based farming system outperformed the pellet-based system, generating higher gross revenue, net profit, and net operating revenue. Overall, FCW offers a cost-effective alternative feed for small-scale cage aquaculture in developing countries.