either endogenous amino acid decarboxylase activity (Halasz et al., 1994) or by the growth of decarbox-ylase positive microorganisms (Halasz et al., 1994;Silla Santos, 1996). The low pH (below 4.5 after 2 days of fermentation) and the physical characteristics of fish silage that lead to a low oxygen concentration within the ensiled fish are favourable for the action
of amino acid decarboxylases (Beutling, 1992)