New treatment for fungus on fish eggs
Ever since malachite green was banned as a compound to treat infections of fungus in hatchery eggs, the aquaculture industry and fish enhancement facilities have struggled to come up with an equally effective and cheap alternative. Some form of formalin treatment is now the norm in much of the salmon farming industry, but this chemical is both expensive and risky to use. Scientists in the USA have now developed an alternative method that may prove both effective and inexpensive for both catfish and eventually salmonids. Sarah Morris of the Stuttgart Daily Leader reports on the reseachers' findings and their recognition by a large research consortium;
Three scientists with the Stuttgart National Aquaculture Research Center (SNARC) were awarded for “Excellence in Technology Transfer” after developing copper sulfate into an effective treatment for fungal infections in catfish eggs. The Federal Laboratory Consortium (FLC) Mid-Continent Region, which consists of more than 100 laboratories in 14 states, honored Ray Carter, Drew Mitchell and Dave Straus in early September. The research team was chosen because of its direct benefit to the catfish aquaculture industry and the large monetary savings in treatment cost. “We were surprised to receive the award and humbled because other winners included things like robots, lasers, fuel cells, microprocessors,” Straus said. “... I’d just like to thank everyone who helped on the project; it was a great team effort.” The award was one of eight given by FLC, according to federallabs.org. It recognizes employees of FLC member laboratories and non-laboratory staff who have accomplished outstanding work in the process of transferring federally developed technology. The nominations for the award are judged by a panel of industry experts, state and local government, academia, and the federal laboratory system judge. Straus said he also entered the team for the award on the FLC’s national level as well for the work, which began in 2006 and continued through the 2009 spawning season. It could only be conducted during the catfish spawning season of May through June. Each experiment lasts two weeks. A 2003 U.S. Department of Agriculture (USDA) catfish industry survey cited fungal infections as the leading cause of egg mortality with 8.3 percent of eggs brought into the hatcheries lost because of it, a SNARC report said. The unrealized value of the lost eggs in 2003 was about $1.1 million. The center initiated the research on the cheaper new treatment and worked with the U.S. Department of Agriculture; Mississippi State University, which has the largest catfish industry and has an agent specializing in catfish hatcheries; the copper sulfate company, Freeport-McMoRan Copper and Gold Inc.; and several catfish hatcheries. “We didn’t have a time frame for the introduction of this technology to the catfish industry, but we were quite surprised at the speed with which the industry used our recommendations. The majority of catfish hatcheries are using this treatment,” Straus said. According to SNARC, fungal infections of hatchery-reared catfish eggs cause serious losses frequently and can result in a $1.1 million loss for the industry each year. The only FDA-approved compounds for fungus control are expensive and have human safety concerns and storage precautions. About $35 would be spent to treat a typical hatchery with 300 hatching troughs with copper sulfate. In comparison, it would cost $2,155 and $1,370 to treat the same hatchery with formalin and hydrogen peroxide respectively. Regulatory action for the product was postponed by the FDA while the group work to gain approval so that hatchery managers can use it now, he said. They are working to gain FDA approval. “To gain an FDA approval for an aquaculture treatment like copper sulfate, we have to do the same things required to get any other human or animal drug approved: Prove how effective it is at treating a disease and how safe it is to the animal given the drug, to humans and to the environment,” Straus said. “We are working on requirements for treating Ich on catfish and treating fungus on eggs. It will be quite an accomplishment when we get this completed.” Freeport-McMoRan Copper & Gold Inc. will partner with SNARC for a seven year exclusivity on FDA-labeling.
