Ultra-high output hybrid nanogenerator for self-powered smart mariculture monitoring and warning system

•A self-powered monitoring and warning system is proposed for distributed smart mariculture.•The remote SMWS is integrated with anti-theft module and sea water sensor module powered by MHTEG.•The multi-electrode pairs of TENG is optimized for improving charge transfer efficiency.•MHTEG exhibits an ultrahigh output energy of 39.6 mJ and excellent energy conversion efficiency of 22.61%.•A peak power of 20.9 W/m3 can reach by MHTEG.