We examined the relation between the environmental or nutritional background and the chemical composition of body tissues and reproductive success in wild (sea‐run, river‐captured, ocean‐captured, landlocked) and hatchery‐reared Atlantic salmon (Salmo salar). More essential fatty acids of the linolenic acid family (n‐3 acids, also called ω‐3 acids) occurred in eggs of wild Atlantic salmon that had the highest percentages of eyed eggs and were highest in ocean‐caught Atlantic salmon. A marked decrease in zinc concentration occurred in eggs and semen of hatchery‐reared fish fed one experimental diet; these fish yielded a lower percentage of eyed eggs than other first‐time spawners. The correlation between zinc levels and spermatocrit in semen of males from five locations was highly significant (P ≤ 0.01). Ovaries of ocean‐captured fish contained 2.5–5 times as much zinc, 5–7 times as much iron, and 4–62 times as much copper as did eggs from sexually mature Atlantic salmon from other sources. An apparent transfer of copper, iron, and zinc from spine and muscle to ovarian tissue was observed in females preparing for spawning. High levels of n‐3 fatty acids, copper, iron, and zinc in gonadal tissues of ocean‐captured Atlantic salmon suggest that these nutrients are essential for reproductive success.
