Canadian researchers analyzed 156 composites prepared from 936 samples of canned tuna sold in Canada in 2006 for total mercury. Each composite represented a single brand.  They found yellowfin tuna, Skipjack tuna, and Albacore tuna had 0.066 mg/kg, 0.132 mg/kg and 0.325 mg/kg, respectively.  The highest found in Albacore tuna was 0.507 mg/kg.  Among the 49 Albacore composites, the second highest mercury content was found at 0.469 mg/kg.In the United States, the Food and Drug Administration and the Environmental Protection Agency now recommends that pregnant women eat more fish including tuna.  But media reports cited ConsumerReports.org as suggesting that pregnant women should avoid all sorts of  tuna because the mercury content in tuna fish was found too high.Robert W. Dabekaa, Arthur D. Mckenziea  and Donald S. Forsytha, Total mercury in canned tuna sold in Canada in 2006, Food Additives & Contaminants: Part B: Surveillance