[en] Between 2002 and 2003, an outbreak of a trout's mass death occurred at the intensive fish culture a Peruvian rural town (Marcara, Huaraz, Peru) where 15,000 from 20,000 fish died. Our objective in the present study was to investigate the high mortality of the trout biomass occurred in period of two months. This study was conducted after the peak of the outbreak has occurred. We collected samples of fishes, water and fish foodstuff which were examined for aflatoxin, metals, toxics and bacteria. We interviewed people who administered the feed pellet. Feed sample preparation, transport and storage. The processing of fish feed was at room temperature which was below 16 deg C. Once prepared the diet it was keep under an appropriate room for a few days before sending to Marcara town. Fishes. 20,000 immature trout larval of rainbow trout (Oncorhynchus mykiss) was acquired from an official Peruvian fish culture. The fishes were fed twice a day. Adjusted of feed ration was based from the monthly sample weight. Pellet sample analysis. The samples were analyzed for aflatoxin Bl (AFB1) according to the method previously published. The sensitivity is 0.1 μg per 1 kg of sample. During the fish development until the peak of the outbreak, the foodstuff to fishes was maintained in plastic bags. At this time the storage room temperature was 18-20 deg. C between 1.00-2.00 P.M. and the humidity rose close to 90 % at the Marcara facilities. Mortality development and Effect on survival. The fishes maintained in 4 pods had a normal surviving until end of November, less than 10 specimen dead by month. The fish outbreaks started the first week of December and continuing until the fourth week of January totalizing 15,000 dead fish from 20,000. The survival of the fish at the first month was less than 50 %. The mortality continues throughout January totalizing 15,000 dead fish and leaving only 25% survival. Laboratory data. The collected samples for analysis were frozen and transported in dry ice to the analysis laboratory. We took the samples on January 23 and it was analyzed on January 25. Aflatoxin Bl was detected in three samples of fish muscle and in the 3 samples of fish feed but it was negative in the 3 water samples. The AFB1 concentration was 10 times in the fish feed than in the fish muscle. In spite of heavy metal residues (lead, mercury and arsenic) were found in the fish samples, those concentrations were below the permissible levels. Volatile toxic residues were negative in water, fish and feed. Only the fish feed samples were contaminated by bacteria (Staphylococcus aureaus). Under favourable conditions of temperature and humidity, the Aspergillus flavus grows on certain foods and feeds, resulting in the production of aflatoxin Bl. For the trout, the highest admissible amount of AFBI in feed is 0.1 μg per kg. The data showed suggest that an improper handling of fish foodstuff (18-20 deg. C and 90 % humidity) was the cause growing of mould and/or spores and consequently it produced an increased concentration of AFBI in fish feed. Liver is strategically located between intestinal tract and general circulation. As AFBI concentration ranged in liver between 10 and 100 ppb, this level is capable to produce an acute hepatotoxicity in the fish stocks. (author)

[en] The article addresses the goals of a national project created with the purpose of systematize all actions of the country in this area, including the definition of the responsibilities of the participating institutions and the actions to ensure consistency with the guidelines of the IAEA in this field.The experiences of projects currently being developed in other countries, as it is the case of the European project ENETRAP, were taken into account in the conception of the project and its contents. The work also describes other actions that this field is developing in the country