Life in the shallows: Tracking fish movement within and beyond the Dutch Wadden Sea

Summary

This thesis explores the role of the Dutch Wadden Sea in the life cycles of migratory fish using aquatic telemetry. While the Wadden Sea’s shallow waters support spawning, foraging, and migration for numerous fish species, persistent data gaps continue to hinder effective management amid local population declines. Through multi-year tracking of species such as European sea bass, thicklip and thinlip grey mullet, and catch records for juvenile tope sharks, this research reveals species- and individual-level differences in migration timing, habitat use, and site fidelity. This work highlights the Wadden Sea’s importance as a seasonal foraging ground for migratory fishes and a potential nursery for endangered species like the tope shark. Furthermore, it underscores the value of using diverse telemetry methods across spatiotemporal scales to inform conservation. Ultimately, the thesis advocates for alignment of research and management with fish movement patterns to enhance population stability and connectivity in coastal ecosystems.