Omega-3 Fatty Acids in Fish from the Laurentian Great Lakes Tribal Fisheries

ABSTRACT

Dietary fish must be assessed for benefits and risks to formulate risk management strategies. This article demonstrates that Laurentian Great Lakes (GL) freshwater species are good sources of omega-3 fatty acids using new data from a small sample (n = 7) of Lake Superior siscowet lake trout (Salvelinus namaycush siscowet) and five other GL fish species’ data. For Lake Superior (LS) siscowets, the saturates, mono-unsaturates, and poly-unsaturates composed 20.1, 40.7, and 39.1% of total lipid weight, respectively. Omega-3 poly-unsaturates (PUFAs) in these fish were more than twice the omega-6 (omega 3/6 ratio = 2.4). The LS lake trout data were combined with earlier LS data collected during the 1980s for eight other species and from five species of Lake Erie fish. All the GL freshwater species were compared with seven other published marine and freshwater fish studies from other global regions. PUFAs were compared based on latitude and marine versus freshwater origin. Differences between marine and freshwater species in omega-3 fatty acid were less at higher latitudes. GL freshwater fish species can be a good source of beneficial fats like marine fish and must be accounted in effective risk communications involving persistent bioaccumulative toxicants in dietary fish.

Key Words:

• tribal fisheries
• omega-3
• siscowet lake trout
• persistent bioaccumulating toxicants
• risk communication.

ACKNOWLEDGMENTS

We acknowledge the financial support from the Chippewa Ottawa Resource Authority of Sault Ste. Marie, Michigan; Dr. and Mrs. Dudley Johnson in Milwaukee, Wisconsin; the Health Professionals Advisory Board of the International Joint Commission (IJC) in Ottawa, Ontario. Each of these parties provided partial funding toward the collection and analysis of the Lake Superior tribal assessment fish. Part of the siscowet PUFA work was completed for the IJC and was included as part of the requirements in fulfillment of the Master of Science degree of Mr. Michael Moths under the research direction of Dr. Dellinger while both were affiliated with the University of Wisconsin–Milwaukee.