Seagrass is known as an ecosystem engineer because of how crucial it is for ocean health. The roots and rhizomes help stabilise the seabed, reduce coastal erosion, and dissipate wave energy, and the grasses help to trap sediment and filter pathogens, improving water quality. Seagrass meadows also sequester carbon as the grasses photosynthesise, and indeed store carbon 16 times faster than tropical forest soils. Seagrass meadows turn barren substrate such as sand into a vibrant ecosystem, providing food and shelter for invertebrates, fish, and birds. The UK may have lost up to 92% of its seagrass meadows, and is now a Biodiversity Action Plan priority habitat. Seagrass meadows globally are threatened by dredging, damage from boats, coastal development, agricultural runoff, and industrial pollution.
The shallow waters of the Irish Sea off the North Wales coast are home to one of the most spectacular seagrass meadows in the UK. This meadow has suffered extensive damage from boat moorings, however, with the chains used to secure the boats ripping up the seagrass and causing significant habitat fragmentation. The damage has been so great that it can be seen from Google Earth and needs to be repaired to restore the meadow back to full health. Fragmentation reduces the resilience of habitats and can reduce their value to wildlife. In the case of seagrass, natural regeneration cannot occur when the habitat is this fragmented and active restoration is required.
Our partner Project Seagrass are working towards restoring damaged seagrass meadows along the North Wales coast, by planting millions of seagrass seeds. The project is not only restoring the fragmented meadow but also introducing new eco moorings that will reduce damage by boats, and providing education on seagrass protection and monitoring.
Reproductive shoots containing seeds are collected from mature seagrass meadows and then placed in aquaria where the seeds drop to the bottom of the tank. The seeds are then placed in hessian bags with some of the rotting seagrass detritus and local sediment and pegged to the seabed, where the seeds germinate through the bag and root into the substrate.