Good news from www.thepaleodiet.com:
"Today steps are being taken by shrimp feed and fish feed manufacturers to rectify any disparity between omega-3 levels in farm-raised and wild fish and shellfish. Recent research has shown that late-stage feeding with feeds containing high concentrations of omega-3 allows the receiving muscle tissues to quickly “catch up.” The result is a farmed product that, overall, requires less omega-3 in its diet over its lifetime, and an omega-3 concentration in the tissue at harvest that is on par with or higher than wild product.
This strategy will (1) help to minimize the amount of expensive fish meals and fish oils used by the aquaculture industry, (2) will still provide us with abundant amounts of omega-3 fatty acids in our diet, and (3) spare valuable wild populations of fish and shellfish from unnecessary and destructive over-harvest. The aquaculture industry understands and appreciates this issue, and is taking steps now to correct real and perceived disparities."