According to D.F. Horrobin (in a recent Medical Hypotheses article,1998,
50; 269-288)about the fatty acids AA, DHA, DGLA and EPA..."there are
only four practical sources of these EFAs: eggs (yolks), meat
(especially organ meat), algae of marine or alkaline lake origin, and
water-based animals, fish, crustacea or molluscs higher up in the food
chain which directly or indirectly consume the algae."

My best, Ellie