PhD thesis: Salt marsh as a habitat for fish in the Wadden Sea (2025)

Salt marshes are one of the most heavily modified and threatened ecosystems worldwide. These habitats are important for a range of fish species, particularly small and juvenile fishes. However, little is known about how fish utilise marsh habitat in the Dutch salt marshes. We investigated this through extensive field campaigns, ecological surveys, diet analyses, and assessments of creek morphology across mainland and island marsh habitats. We demonstrated that marsh habitat is important for fish, but that the value of the human made mainland marshes could be improved. This could be achieved by reintroducing a salinity gradient to the mainland creeks, increasing their capacity to retain water, and decreasing the density of livestock in intensively grazed areas. This would improve the habitat quality of salt marshes for fish.