Resent research in the Baltic Sea indicates that two environmental issues may be intrinsically linked; availability of vegetated recruitment habitats appears to limit large predatory fish, whereas predatory fish indirectly control nuisance algae that otherwise smother vegetation.

Research on how vegetation and fish facilitate each other
The project Plant-Fish will explore the hypothesis that vegetation and predatory fish facilitate each other via a positive feedback loop, which enhances ecosystem health. To test this hypothesis, we will first assess the effect of vegetation on coastal fish stocks using statistical modelling based on fish surveys from the last decade along the whole Swedish east coast. We will then assess if predation from adult fish benefits vegetation, and whether this feeds back positively on juvenile fish, using a detailed community survey along the central Baltic Sea coast. Finally, we will experimentally test if vegetation and predatory fish together strengthen ecosystem resilience to eutrophication.

These results will inform managers about

  1. threshold levels of vegetation and predatory fish needed to uphold multiple ecosystem services,
  2. the impacts of boat traffic, dredging, fishing, and eutrophication on these services, and
  3. how integrated management of habitats, vegetation and fish could increase the health of the Baltic Sea.