Extended Data Fig. 1: Variation in nutrient content across all food fish species (grey), and for specific countries (green; first column: Iceland; second column: Kiribati; third column: Kenya), as depicted by the first three principal components using all nutrient content values (for example, protein, iron, zinc, calcium, vitamin A and omega-3s [EPA+DHA]).

Complementary species (orange) are the species included within optimal portfolios, while the best species (purple) is the single species that minimizes the biomass needed to support all RDAs. When a single best species is also included in an optimal portfolio, it is orange and outlined in black. More biodiverse countries are typically represented by a wider variation in nutritional trait space. Species included in the optimal portfolio are drawn from the edges of nutritional space, but do not overlap.