AbstractGlobal food security relies on protein and essential micronutrients provided by seafood (Latham 1997, Golden et al. 2016). The importance of seafood-derived micronutrients to human health suggests that consuming diverse aquatic species could enhance human well-being (Penafiel et al. 2011). Biodiversity provides important ecosystem benefits to humanity (Cardinale et al. 2012), causing concern that declining biodiversity may affect human health (Myers et al. 2013). A key scientific question remains unanswered - does increasing species diversity in seafood diets improve their ability to meet nutritional needs? Here we used biodiversity-ecosystem functioning theory to test whether increasing species diversity allows seafood diets to fulfill multiple nutritional requirements simultaneously, a condition necessary for human health. We found that aquatic species with different ecological traits have distinct and complementary micronutrient profiles. The same complementarity mechanisms that generate positive biodiversity effects on ecosystem functioning in terrestrial ecosystems also operate in seafood assemblages, allowing for more diverse diets to yield increased nutritional benefits. Notably, nutritional metrics that capture multiple micronutrients essential for human well-being depend more strongly on biodiversity than ecological measures of function such as productivity. In contrast to the micronutrients, we found that increasing species diversity did not increase the amount of protein in seafood diets. We unify biodiversity-ecosystem functioning theory and human nutrition, demonstrating a direct link between multiple nutritional benefits of biodiversity and an ecosystem service underpinning human wellbeing. Our findings demonstrate that minimizing biodiversity loss at local and global scales will benefit global food and nutrition security.Significance statementFood security is not simply about maintaining yields, it is also the need for a stable supply of nutritionally diverse foods. Obtaining nutritious food is a major challenge facing humanity, and aquatic ecosystems can help meet this goal. From the perspective of human nutrition, how much biodiversity is enough biodiversity? How ecological processes influence the capacity of aquatic ecosystems to provide nutritionally diverse diets is largely unknown. We found that aquatic biodiversity enhanced nutritional benefits, because edible species showed distinct and complementary multi-nutrient profiles. Protein supply was independent of biodiversity, but the supply of micronutrients increased with biodiversity. Extending the multifunctional benefits of biodiversity to human nutrition underscores the need to minimize biodiversity loss for the benefits of humanity.
Species diversity, invasion success, and ecosystem functioning: disentangling the influence of resource competition, facilitation, and extrinsic factors
