Aquatic biodiversity enhances multiple nutritional benefits to humans

Humanity depends on biodiversity for health, well-being and a stable
environment. As biodiversity change accelerates, we are still discovering
the full range of consequences for human health and well-being. Here, we
test the hypothesis -- derived from biodiversity - ecosystem functioning
theory -- that species richness and ecological functional diversity allow
seafood diets to fulfill multiple nutritional requirements, a condition
necessary for human health. We analyzed a newly synthesized dataset of
7245 observations of nutrient and contaminant concentrations in 801
aquatic animal taxa, and found that species with different ecological
traits have distinct and complementary micronutrient profiles, but little
difference in protein content. The same complementarity mechanisms that
generate positive biodiversity effects on ecosystem functioning in
terrestrial ecosystems also operate in seafood assemblages, allowing more
diverse diets to yield increased nutritional benefits independent of total
biomass consumed. Notably, nutritional metrics that capture multiple
micronutrients essential for human well-being depend more strongly on
biodiversity than common ecological measures of function such as
productivity, typically reported for grasslands and forests. Further, we
found that increasing species richness did not increase the amount of
protein in seafood diets, and also increased concentrations of toxic metal
contaminants in the diet. Seafood-derived micronutrients are important for
human health and are a pillar of global food and nutrition security. By
drawing upon biodiversity-ecosystem functioning theory, we demonstrate
that ecological concepts of biodiversity can deepen our understanding of
nature’s benefits to people and unite sustainability goals for
biodiversity and human well-being.