In order to obtain information on bacteriological aspects of the South Brazilian fish industry, with the object of finding out where and how to improve the actual situation for the better quality of fresh fish, microbiological conditions in short distance trawling, long distance trawling, purse-seining, whaling, wash-water, ice and wooden fish boxes, were studied by means of total aerobic counts on peptone-fish-extract-agar and coliform bacterial counts on violet-red-bile-agar and by the most probable number method. In short distance trawling, fish at capture showed 10(5) - 10(7) level of bacterial counts per cm² of skin surface, and an almost equal level at landing with ordinary presence of coliform bacteria. In long distance trawling, bacterial count at capture was 10³ per cm² of skin surface and at landing, 10(4) - 10(6) or higher. In purse-seining and whaling, 10(5) - 10(6) level contamination was obtained at landing. Fishery environmental conditions showed rather high bacterial counts of 10(5) - 10(6) per cm² of deck surface, 10(5) - 10(6) per cm² of used wooden fish boxes (inside surface), 10(5) - 10(6) per ml of melted ice, and 10³ - 10(4) per ml of wash-water from canal, with the usual presence of coliform bacteria. Some methods to improve the above mentioned bacteriological conditions were discussed. The use of chlortetracycline in immersion method or as an additive to ice, chlorination and filtration of canal water for washing purpose, and the use of cleaner fish boxes are recommended.
