Only a very slight improvement in keeping quality of dressed halibut (Hippoglossus hippoglossus) and black cod (Anoplopoma fimbria), as evidenced by differences in viable bacterial population and trimethylamine content of excised muscle, results when the fish are stored in crushed tap water ice containing 0.1 per cent benzoic acid instead of in similar ice without this compound. The methods employed for a relatively simple determination of both viable bacterial population and trimethylamine content of the same sample of muscle are described, and the limitations of these as criteria of the relative age of dressed fish stowed in crushed ice are discussed. The "tyrosine" reaction failed to show greater effectiveness for benzoic acid ice; the values increased during storage, but were too irregular to serve as a safe criterion of spoilage.