Topic: Review
http://slate.msn.com/id/2093814/

Eat Catfish!

hey, wait a minute The conventional wisdom debunked.

The Perils of Aquaculture
It's the salmon farms, not the risks of dioxin in farmed salmon, that we ought to be worried about.
By Douglas Gantenbein
Posted Tuesday, Jan. 13, 2004, at 6:42 AM PT

What's in your salmon?

It turns out that farmed-raised salmon, touted as inexpensive fare for heart-healthy diets, may not be such a good mealtime addition after all. On Jan. 9, the journal Science published an article detailing an exhaustive analysis of some 700 farm-raised salmon. Most had levels of dioxin--cancer-causing chemicals that are the byproduct of various industrial processes--as much as 11 times higher than those found in wild salmon. The best explanation for the big dose of dioxin is that farm-raised fish are eating badly themselves--food pellets mostly derived from ground-up fish. A less-diverse diet than wild salmon eat, it allows concentrations of chemicals to pass easily to farmed salmon.

There's a certain "So what?" element to all this. The tested fish were not skinned or cooked, two steps that greatly reduce dioxin. And, as many food experts have pointed out, the added risk of the dioxin is probably more than compensated for by the benefits of eating salmon. That's because salmon, an oily fish, is rich in omega-3 fatty acids, a substance that almost certainly helps protect against heart disease and may also reduce the risk of cancer and Alzheimer's. Salmon--even farm-raised salmon--also are low in mercury, a chemical prone to show up in tuna and other fish. The average American is far more apt to croak from heart disease due to too many Big Macs than from cancer caused by a few helpings of ranch-raised salmon.

That doesn't let farmed salmon off the hook, though. Why? Because the aquaculture industry that creates them also creates plenty of other problems. Farm-raised salmon were largely unheard of 20 years ago. But after getting their start in northern Europe and then spreading to places such as Chile and British Columbia, Canada, "salmon farms" grew rapidly. Today they account for some 60 percent of salmon worldwide--1.4 million metric tons in 2002, which is a lot of salmon steaks. The abundance of farmed salmon has helped make a fish that once was largely a luxury item (or an expensive canned fish) into a commonplace meal in homes and restaurants.

[for rest of the excerpted article follow link above]

Aquaculture doesn't have to be a bad deal. Catfish and other species are raised successfully and fairly cleanly by fish farmers. (Asian shrimp farms, though, may be even worse than salmon farms.) Good aquaculturalists carefully monitor water quality, use minimal antibiotics and pesticides to keep fish healthy, and ideally raise their crop in closed systems--not in pens stuck near the open ocean. (And they push for better quality pellets to feed their fish, too.) If the current scare inspires consumers to make it clear they want wild salmon, not farm-raised fish, then perhaps the market will help rein in what has become a marine menace.