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In the wild, salmon, tuna or other active, migrating fish get a lot of exercise. But when these fish are raised in captivity, without predators or the need to fight their way upstream against the current, they turn into fish couch-potatoes.
And not unlike sedentary humans, lethargic fish are more prone to getting sick. As many as 20 percent of farmed salmon die in captivity—apparently, because they’re simply out of shape.
A new technical book called Swimming Physiology of Fish presents scientific research on how various training routines, water turbulence, diet and even the use of robotic fish as “swim trainers” can keep captive fish conditioned.
This “fishical” fitness research has shown that when captive salmon exercise regularly, they grow bigger, have stronger hearts and immune systems, and are healthier than their sedentary brethren. For example, a Norwegian study found that when salmon had to swim against an artificial current they were much less likely to get a common fish virus than their buddies in still water. [Vincente Castro et al., Aerobic training stimulates growth and promotes disease resistance in Atlantic salmon (Salmo salar)]
The bottom line? Healthier profits for fish farmers, and healthier fish on your dinner table.
—Gretchen Cuda Kroen
[The above text is a transcript of this podcast.]
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Add CommentInteresting research from Norway. Here on the West Coast of Canada we make sure our fish don't turn into 'couch potatoes' by farming them in sites with strong tidal flows. This keeps them swimming and is good for their health and also the environment. And only about 10 per cent of our fish in the ocean don't make it to harvest. The fish we harvest are healthy and strong, making for an excellent source of protein.
Reply | Report Abuse | Link to thisDisclosure: I work for Mainstream Canada, a BC salmon farming company, and am also a SciAm subscriber.
Hmm...this is interesting, never heard about this kind of stuff before. Almost all the fish now we eat in China are raised in captivity, how about their healthy condition?
Reply | Report Abuse | Link to thisSo it would stand to reason that this would also be true of terrestrially farm species as well? I'm not sure that I trust this data. Xiaoming, Chinese aquaculturist are not bound by the same laws regarding drugs as we are in the states. I would seriously consider the health a Fish farmed in China based on that before I would worry about the affect their activity level is having on health. In the US the drugs we are cleared to use in the US are very limited. It includes things like ice and salt. When an antibiotic is used on fish destined for the table, we must wait thirty days after treatment to harvest so that the drug has cleared the tissues. In China and many other countries from which we import fish this is not the case. Back in 2005 traced of Malachite Green were found in the tissues of food fish which were raised in China. Malachite Green in addition to being carcinogenic, fractures chromosomes. I'm taking the time to write all of this because there is a lot of misinformation surrounding modern fish culture. Articles like these really don't help. Even if the research and experimentation is sound, its significance is misleading unless but in the proper context.
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