A serious problem may be emerging for fish hatcheries in the United States, according to Al
Barney, hatchery manager with the Nisqually Tribal Hatchery in Olympia, Washington. It’s due to increasingly restrictive regulations from the Environmental Protection Agency (EPA) concerning the chemicals that may be used to treat water for fish farming.
Barney, who has been in the aquaculture business since the 1980s, told Hatchery International that he’s convinced that if the agency continues down its present path, it will be nearly impossible for salmon and other fish hatcheries to operate because of the ever-tightening rules on what chemicals may be used for treating fungus on salmonid eggs, and the fish themselves.
Particularly problematic, he said, is that he’s had to operate in relative secrecy for three years while doing research he rates as significant for the industry: proving that putting copper pot-scrubbers in the supply water prevents the development of fungus on salmonid eggs and juveniles.
It has no adverse effect on the fish, Barney emphasizes, adding that it’s also cheap: copper pot-scrubbers are inexpensive to buy, they dissolve only very slowly and need only be used in small numbers.
But Barney, who brought attention to his innovation through this magazine some years ago, told H.I. that he’s encountered great difficulty getting anyone to support his work, even to the point of outright opposition, and threats to his job. He stated that this has caused him to work clandestinely, to prove to himself – and perhaps a handful of other people – that using the copper pot-scrubbers is less dangerous for both humans and fish than using formaldehyde as a fungicide, which he believes may shortly be banned by the EPA for use in hatcheries.
Barney said that he had come across an official in the Idaho Department of Fish and Game who had followed up on his experiments and proved (to himself, if no-one else) that low concentrations of dissolved copper, from scrubbers or other small copper items, into well-treated, pure fresh water, can be extremely effective as a fish-egg fungicide.
Barney’s studies have proved to him that the pot-scrubbers are most effective in harder rather than softer water. He also said that tests by the official in Idaho using 5-cent ‘nickel’ coins rather than pot-scrubbers showed that the small amount of another metal in these alloy coins makes them more effective than the scrubbers.
Barney believes opposition to the idea of using pot-scrubbers (the brand he uses are 99.97% pure copper) is because of the many instances of copper leachate from mines and other activities killing fish, especially salmonids. He said he has no doubt that in those cases the concentrations of copper and other toxic chemicals in the waste were simply too high for any fish to survive.
– Quentin Dodd