Alternatives for trap monitoring in large rivers and lakes: Camera monitoring and eDNA sampling as alternative for conventional trap monitoring

Wageningen Marine Research (WMR) executes a variety of fish monitoring programs in the Dutch rivers and lakes. These programs are often commissioned by the Ministry of Agriculture, Nature and Food Quality (Ministerie van Landbouw, Natuur en Voedselkwaliteit, LNV) and Rijkswaterstaat (RWS). Some of the activities within the monitoring programs use traps for trend monitoring of diadromous fish which are present in the large lakes and large rivers for a limited amount of time during migration periods (spring and fall). In this project two potential alternative methods are tested and evaluated: 1) camera monitoring and 2) eDNA sampling. These pilot studies will provide first insights in the applicability of both methods as an alternative for conventional trap monitoring.