Manufacturing processes in fish canning industries generate a considerable amount of solid waste that
can be digested anaerobically. The aim of this research was to study the biochemical methane potential
of different solid fish waste. For tuna, sardine and needle fish waste, around 0.47 g COD–CH4/g CODadded
was obtained in batch experiments with 1%TS; whereas for mackerel waste, the methane production
attained 0.59 g COD–CH4/g CODadded. The increase in the waste/inoculum ratio, from 1.1–1.3 to 2.8–
3.3 g VSwaste/g VSinoculum, led to overload due to VFA and LCFA accumulation. Afterward, co-digestion
assays of fish waste with gorse were undertaken but the biochemical methane potential did not improve.This work was supported by project QREN SI-I&DT, number 2509 from 15/5/2008. Marta Eiroa wishes to express her gratitude to the "Xunta de Galicia" (Spain) for her post-doc fellowship (Angeles Alvarino) and Jose Carlos Costa to the "Fundacao para a Ciencia e a Tecnologia" (Portugal) and "Fundo Social Europeu" through the Grant SFRH/BDP/48962/2008. The authors thank the Ministry of Science and Innovation of the Spanish government for the funds provided through the Torres Quevedo Programme (PTQ-09-02-01663) and the collaboration with Bilega Energia S.L
