By Yojaira Paternina Cordoba*
Colombia: Bacterial outbreaks threaten fish culture in Betania.
Production of tilapia and other species, one of the principal export industries in the Huila region of Colombia, has come to a virtual standstill. The Colombian Institute for Agriculture and Livestock (ICA) suspended and prohibited until further notice the stocking of fingerlings produced in cages in the reservoir. This temporary preventive measure was adopted as a consequence of the mass mortality of fish, which has been accumulating and provoked in part by widespread presence of bacteria.
The pathogenic agent responsible for the mortality was confirmed by the ICA’s Center for Diagnostics. The principal opportunistic agent was determined to be a type of Aeromonas spp found in the water column. The floating cages also provide a breeding ground for fungus and other microorganisms.
“The outbreak of disease has reached very high levels, with more than 30% of the fish affected in any given cage,” stated an expert who visited the zone. The particular pathogen in question benefits from the conditions within the growout cages, surviving and multiplying rapidly. This in turn puts sanitation and biosecurity at risk, not to mention the economic sustainability of the businesses involved.
At this time, losses are calculated to exceed **COP$1 billion, or USD$420,000. During Holy Week, fish were selling for USD$2.15 per kilo according to Efren Tovar, the President of the Fish Farmers Association of Huila.
The worst effects are concentrated in the cages found in the northern part of the reservoir near the generator plant. According to experts, these impacts are spreading and mortality is increasing throughout the reservoir.
Specialists indicated that sufficient controls were not in place to prevent the current outbreak, and that these situations can build on themselves, with sick and moribund fish serving to accelerate deteriorating conditions and the spread of disease. Additionally, many producers did not follow recommendations to minimize adverse impacts when low oxygen levels began 15 days earlier according to observers. (Editor’s note – for background on this story, see the Latin American Report in our last issue). Management measures initially adopted when mortalities began were not sufficient to head off this emergency. According to technical observers, many fish farmers did not take recommendations to heart to reduce feeding and stocking rates, and continued to increase their loads on their production systems and the reservoir as a whole.
The situation was initially localized in certain cage farms, but over time the disease problems were propagated in other sectors of the reservoir. Because of this situation, management recommendations are now being adopted as regulations. “New stockings of fingerlings will further increase the cultivated biomass and only add to mortality and losses within the reservoir,” the chief of the ICA emphasized.
All aquaculture establishments, from this date forward, must abstain from conducting any fingerling stocking, as a preventive measure. All fish culture installations within the reservoir must also conduct the collection and final disposal of fish mortalities, now and whenever necessary in the future, in an adequate manner. At the same time, they must disinfect all cage netting with products that are approved by the ICA. ICA personnel will assume the role of inspectors and sanitary police, and exercise necessary controls in the intervention zone.
Salmon Aquaculture Installations Damaged by the Volcanic
Eruption in Chile Represent 2.5% of the Freshwater Capacity.
Due to the recent eruptions of the Calbuco Volcano in Chile, the salmon industry association SalmonChile stated that although Chilean salmon farming involves some 200 facilities in total, only 8 of those operate in the emergency zone impacted by the disaster.
However, with regard to those 8 operations at risk, four have suffered severe damage or total losses; one is still being evaluated, with some portion of the fish having been saved; and the other three have had all remaining fish stocks transferred to other sites. Losses from the five impacted sites equate to roughly 2.5% of the industry’s total freshwater capacity.
The trade association also reported that within these 8 facilities the production levels equate to 25 million fish, out of a total of 300 million. This represents roughly 8.3% of the current production in the freshwater phase.
According to SalmonChile, the emergency protocols enacted by SERNAPESCA (Chile’s National Fisheries Service) have functioned adequately, allowing special measures to authorize movement of fish while still following established biosecurity requirements and conditions.
The organization also stated that fish in the first phase of production in freshwater, as impacted in these facilities, can more easily be replaced. If losses cannot be quantified with anticipation, they can be delimited.
The association reported that 100% of the workforce was evacuated without problems. In terms of social assistance, the organization and private companies are delivering assistance and various necessities for those persons forced to stay in shelters.
Yojaira Paternina Cordoba has a degree in Animal Husbandry from the National University of Colombia. She currently manages production, technical and marketing activities at Piscicola del Valle, S.A., specializing in production of red tilapia (Oreochromis sp.) and the white cachama (Piaractus brachypomus).