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

Abstract

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.

Fatty acid composition and concentration of alternative food of Semipalmated Sandpipers (Calidrispusilla) in the upper Bay of Fundy, Canada

“…PUFAs, particularly the short-chained varieties, have been shown to be more easily mobilized than others across a range of taxa, including mammals (Raclot 2003) and both a songbird and shorebird (Price et al 2008). Both n-3 and n-6 PUFAs are essential FAs; there is phylogenetic consistency in the fact that they cannot be efficiently synthesized by vertebrate consumers (Hulbert and Abbott 2011) and must be obtained through dietary sources (Arts et al 2001). Although limited, existing evidence for birds is consistent with these findings (Iverson et al 2007;Twining et al 2016a).…”

Fatty acid composition as biomarkers of freshwater microalgae: analysis of 37 strains of microalgae in 22 genera and in seven classes

“…In aquatic food webs, most fatty acids (FAs) are synthesized by phytoplankton and bacteria before being transferred via herbivorous invertebrates to fish and ultimately humans (Arts et al 2001). Phytoplankton generate polyunsaturated FAs (PUFAs) from de novo synthesis of palmitic acid and further enzymatic elongase and desaturation reactions , Cagilari et al 2011.…”

“…For zooplankton, these EFAs are needed to achieve optimal somatic growth and reproduction, whereas fish also require these molecules for disease resistance, neural tissue and eye development, pigmentation, and reproduction (Sargent et al 1999). The most critical EFAs for zooplankton and fish are eicosapentaenoic acid (EPA,20:5ω3), docosahexa enoic acid (DHA,22:6ω3), and arachidonic acid (ARA, 20:4ω6) (Arts et al 2001). The importance of marine phytoplankton (e.g.…”

Efficiency of transfer of essential polyunsaturated fatty acids versus organic carbon from producers to consumers in a eutrophic reservoir

“…Some biomolecules are essential to the consumers because they cannot be synthesized de novo by them. For instance, polyunsaturated fatty acids (PUFA) of x-3 family with 18-22 carbon atoms (C18-C22) are essential for all animals, including humans (Arts et al 2001;Wacker and Von Elert 2001;Copeman et al 2002;Garg et al 2006). Animals, unlike plants, cannot synthesize x-3 PUFA (Bell and Tocher 2009;Lands 2009).…”