Yet another reason why fish-farming doesn’t work: last January 250,000 rainbow trout from an Idaho hatchery died from an outbreak of Ichthyophthirius multifiliis, the loss being equal to 8% of the annual “catchable sized output” or $40,000 worth (including fish food and labor). The manager of the fishery, Tom Frew noted that the fish normally can overcome outbreaks, but the fish were far-too-numerous and weak, making them easy prey for the protozoans. The article notes that an outbreak occurred last year as well, and they are likely going to continue into the future as there is apparently no way to remove the protozoans (which during part of their lifecycle exists as cysts on the bottom) without rebuilding this site. Because of this massive loss other fisheries have to pick up the slack and produce more fish, which makes me wonder if the ramped up production is going to make the other sites more susceptible to problems as well. Simply put, this was a huge waste of time, money, and resources and it sounds like it’s going to continue as there are no plans to make any changes; fish will continue to become infected and die in over-crowded pens every year despite the need to sterilize the hatchery. I also have to wonder about the fish that are being released into the wild from these hatcheries; I don’t doubt that they’re carrying some diseases and could potentially input inferior genetic material, weakening wild stocks. I don’t know about you, but this seems to be the most poorly managed and executed idea I have come across lately, all so a few fisherman can catch some trout.
250,000 fish die from “Ich”8 05 2007