Combining sampling gear to optimally inventory species highlights the efficiency of <scp>eDNA</scp> metabarcoding

Abstract Biodiversity surveys may require the use of multiple types sampling gear to maximize efficiency species detections, yet few studies have investigated how optimally distribute effort among gear. In this study, we conducted eDNA metabarcoding and capture‐based (electrofishing, fyke netting, gillnetting, seining) sample fish richness in a large northern temperate lake. We evaluated success methods individually combination determine allocation cost across that provides optimal approach for lake‐wide inventories. found detected more than any other method, including 11 were not with approach. Optimal analyses revealed is maximized when most or budget allocated metabarcoding, smaller allocations seining netting. capture showed similar patterns spatial heterogeneity community habitat types, pelagic samples forming group was distinct from nearshore samples. Our results indicate rapid cost‐efficient tool biodiversity monitoring assessing complementarity can inform development approaches measuring richness.