Comparing aquatic environmental DNA collection methods across a diel cycle in a lotic system.
Environmental DNA (eDNA) sampling often requires a single sample collected at one point in time, a snapshot approach that provides limited information on biodiversity across temporal scales. To address this limitation, water samples were collected over 25 hours from a single site on the Tangipahoa River in Louisiana, USA utilizing both active and passive eDNA sampling methods. Active sampling involved taking water samples from a predefined location every hour for 25 hours, while passive sampling included deploying a stationary sampling device for the same duration. All water samples were filtered using glass microfiber filters, extracted, PCR amplified (12S mtDNA), and sequenced using Illumina technology following a pre-established protocol. These findings underscore the importance of considering the timing of active eDNA sample collection and highlight the need for passive eDNA sampling methods when studying fish assemblages. This study illustrates the complexities involved in eDNA-based fish assemblage assessments and emphasizes the necessity of further research to optimize methodologies for accurate biodiversity monitoring.