Elemental and biochemical nutrient limitation of zooplankton: A meta-analysis

Primary consumers in aquatic ecosystems are frequently limited by the quality of their food, often expressed as phytoplankton elemental and biochemical composition. However, effects of these food quality indicators vary across studies, and we lack an integrated understanding of how elemental (e.g., nitrogen, phosphorus) and biochemical (e.g., fatty acid, sterol) limitations interactively influence aquatic food webs. Here we present results of a meta-analysis using >100 experimental studies, confirming that limitation by N, P, fatty acids, and sterols all have significant negative effects on zooplankton performance. However, effects varied by grazer response (growth versus reproduction), specific manipulation, and across taxa. While P limitation had greater effects on zooplankton growth than fatty acids overall, P and fatty acid limitation had equal effects on reproduction. Furthermore, we show that: nutrient co-limitation in zooplankton is strong; effects of essential fatty acid limi...