Baltic Sea seagrass restoration pilot starts

The first pilot seagrass meadows are being planted on Germany's Baltic coast this summer. The Rewilding Oder Delta team is conducting the trial as part of its new Blue Stepping Stones initiative, which is funded by the German Federal Environmental Foundation.

This marks a shift from planning to action after years of scientific research and habitat mapping. The initiative aims to restore a network of marine habitats along the coast to reconnect ecosystems and support wildlife recovery. The team began with underwater surveys in 2023 to identify remaining fragments of common eelgrass around the island of Ruden.

Testing restoration techniques

A small-scale trial is now underway to test if seagrass can establish successfully under local conditions. The team will monitor the plots closely over the coming months. The results will refine future restoration efforts.

"Restoring nature at sea requires patience, curiosity, and a willingness to learn," says Ringo Behn, Rewilding Oder Delta's Coastal Ecosystems Coordinator. He stated the pilot is about understanding how these ecosystems respond in real-world conditions.

The lessons learned are intended to be invaluable for scaling up marine rewilding across the Baltic. The wider region has seen its marine habitats degraded by decades of pollution, habitat loss, and unsustainable use.

The value of seagrass meadows

Seagrass meadows are among the most valuable ecosystems in the Baltic Sea. In this region they are dominated by common eelgrass, one of around 70 seagrass species found globally. These flowering plants grow in shallow, sheltered coastal waters.

They provide critical nursery grounds for fish like Atlantic herring. The meadows shelter countless marine species, stabilise seabed sediments, and improve water quality. They also reduce coastal erosion and capture significant amounts of carbon.

Much of this habitat has disappeared in recent decades. Nutrient pollution, climate change, fishing activities, and physical disturbance are the causes. Restoring the meadows could strengthen coastal resilience, support fisheries, and contribute to climate mitigation.

An innovative planting method

The pilot uses a technique developed by the German company ZosteraTec. Young seagrass plants are first established on biodegradable, plastic-free textile ropes. These ropes are made from old seagrass. The prepared ropes are then gently rolled out across the seabed, similar to laying turf.

This method has shown promise in more sheltered Baltic waters. The plantings around Ruden will test its performance in more exposed conditions. Stronger wave action there presents an additional challenge. Factors like wave exposure, sediment movement, and water quality will influence the seagrass's development.

Researchers involved in Blue Stepping Stones will also develop habitat suitability models. These will identify where restoration is most likely to succeed. The team will explore sustainable ways to source native seagrass plants, prioritising material from aquaculture or naturally washed-up plants. This aims to protect remaining wild meadows while creating a sustainable planting source.

Building a connected network

The long-term ambition is to restore a connected network of marine and coastal ecosystems. This network would support richer biodiversity, healthier fisheries, and greater climate resilience. The initiative's name comes from the idea of creating connected "blue stepping stones" across the Baltic seascape.

Seagrass restoration is just the first step. Future phases could expand to other habitats. The work is part of Rewilding Oder Delta's broader effort to restore rivers, wetlands, and coastal landscapes throughout the Oder Delta region.

Complementing the practical work, a planned marine education hub in Peenemünde will help visitors and local communities discover the Baltic Sea's richness. It will feature exhibitions, workshops, and guided activities to build support for marine rewilding. Together, these efforts aim to build a foundation for healthier seas across the Baltic.