Essential fatty acids in aquatic ecosystems: a crucial link between diet and human health and evolution

Fatty acids (FA) are inextricably linked with key physiological and biochemical processes and are thus integral to proper ecosystem functioning. FA not biosynthesized effectively by animals are termed essential fatty acids (EFA). These EFA are important "drivers" of ecosystem health/stability and are therefore highly conserved in aquatic food chains. Aquatic organisms have been and continue to be our primary source of readily available EFA. However, overfishing and our burgeoning population may be acting in concert to threaten our access to this source of EFA. Here, we review the marine FA synthesis/transport cycle and traditional and nontraditional sources of EFA. Our review suggests that, while some traditional sources of marine oils (e.g., tuna) are in steady decline, other sources (e.g., krill) and technologies (e.g., heterotrophic fermentation) hold great promise for maintaining our access to EFA. We provide a minireview which illustrates that EFA contribute to our health and well-being. Finally, there is growing evidence that EFA have been an important force in our past evolution, leading us and others to speculate that an unbroken link exists between EFA, our present health, and, in all likelihood, our continuing evolution.