The Wadden Sea is one of the world’s largest coherent intertidal wetlands. With more than 140 fish species recorded to date, the fish community is exceptionally diverse. About 20 species remain in the region for (almost) their entire life cycle; others depend on the Wadden Sea at least for one stage of their life. These include many flatfish, which spend their juvenile phase in the area, diadromous species, which pass the region on their way to marine or fresh-water spawning sites, and seasonal migrants.
The populations of many fish species in the Wadden Sea have steeply declined in recent decades. Basic understanding of essential processes and functional pathways is often still missing, hampering effective and efficient fish conservation. For this reason, Danish, Dutch and German fish experts developed conservation objectives for fish – the so-called Trilateral Fish Targets, which were adopted as part of the Wadden Sea Plan (2010) at the 11th Trilateral Governmental Conference (Sylt, 2010). These are
- Viable stocks of populations and a natural reproduction of typical Wadden Sea fish species;
- Occurrence and abundance of fish species according to the natural dynamics in (a)biotic conditions;
- Favourable living conditions for endangered fish species;
- Maintenance of the diversity of natural habitats to provide substratum for spawning and nursery functions for juvenile fish;
- Maintaining and restoring the possibilities for the passage of migrating fish between the Wadden Sea and inland waters.
At the 12th Trilateral Governmental Conference in Tønder (2014), Denmark, Germany and the Netherlands agreed to work on the further implementation of these Trilateral Fish Targets. It was decided to advance these targets by means of a Trilateral Wadden Sea Swimway Action Programme. This Programme was developed in 2018 by a trilateral coordination group with contributions by research institutes, nature management organizations and authorities. The Wadden Sea Swimway Action Programme includes proposals for research, monitoring, policy, measures and communication.
The main aspects of the Programme were transferred to a Swimway Vision, which was annexed to the Leeuwarden Declaration (2018) and signed by ministers of the three states at the 13th Trilateral Governmental Conference, Leeuwarden, in May 2018.
The vision focusses on involvement of stakeholders whose activities may have a direct or indirect impact on fish, such as researchers, commercial and recreational fishermen, water authorities, relevant governmental agencies and NGOs. Their signing of a supportive statement for the trilateral Swimway vision at the Leeuwarden Conference demonstrates their commitment and marks the start of the Swimway Vision.