Carbon and nitrogen budget in fish-polychaete integrated aquaculture system

Integrated multi-tropic aquaculture (IMTA) systems have been used in China for many years and have achieved significant economic, social, and ecological benefits. However, there is still a lack of benthic bioremediation species that can effectively utilize the aquaculture particulate organic waste in the system. Polychaete Perinereis aibuhitensis Grube is used as an environmental remediation species for large-scale aquaculture to reduce particulate organic waste, which is of great significance to environmental protection. To improve bio-elements utilization efficiency, P. aibuhitensis was applied for IMTA indoor fish ( Hexagrammos otakii ) farming. Results showed that in the system, production of 1 kg of the fish discharged 2 141–2 338 mg of carbon and 529–532 mg of nitrogen, while in the monoculture of the fish, the figures were 3 033–3 390 mg and 764–794 mg, or 24.84%–35.26% and 30.35%–33.32% less, respectively. This approach promoted IMTA technology that could utilize the particulate organic waste from intensive aquaculture and reduce the adverse environmental effects.