We monitor and protect critical seagrass meadows in the Bay of Ranobe
Seagrass are one of the most productive and valuable ecosystems in the world. They provide critical sheltered refuges and feeding areas for a diverse community of marine life (from tiny invertebrates to large fish, crustaceans, and turtles) thereby providing the basis of coastal fisheries productivity. Furthermore, they stabilize bottom sediments, act as hydrodynamic barriers reducing wave energy, and filter coastal waters of nutrients and contaminants. Seagrass beds provide a further barrier to silt and mud that could otherwise smother coral reefs. They also capture and store a large amount of carbon dioxide from the atmosphere. Over 95% of the carbon in seagrass meadows is stored in the soils and overall these ecosystems are responsible for 10% of this “Blue Carbon” buried annually in the ocean. Therefore, like another important blue carbon ecosystem, mangroves, they play and important role in reducing the impacts of global climate change.
Unfortunately, due to their location on land-sea interface, seagrass beds are subject to many anthropogenic impacts including eutrophication, sedimentation, human development, and fishing net trawling. Seagrass beds are under threat globally with coverage being lost at a rate of 1.5% per year. In addition to the loss of their important ecological and hydrodynamic functions, when degraded or destroyed, seagrass emit the carbon they have stored for centuries into the atmosphere and oceans, becoming sources of greenhouse gases.
We have implemented a seagrass surveying programme to map and assess the status of the seagrass beds in the bay; forming the crucial first steps towards their protection. This research has enabled us to begin to establish seagrass reserves, involving zoning for strict protection and restricted use, with the initial aim to protect at least 10% of the total seagrass habitats in the Bay of Ranobe.
Seagrass meadows in the Bay of Ranobe are under a variety of pressures comprising their survival such as climate change, destructive fishing practices, and reduced light levels due to sedimentation and high nutrient loading. It is therefore important to protect these valuable habitats to preserve their critical ecological, hydrodynamic, and Blue Carbon functions. In 2016, we established a limited-use protected zone of more than 400 hectares over critical seagrass habitat in the Bay of Ranobe. This protects the habitat from destructive fishing methods, such as the use of trawling seine nets, providing relief to juvenile fish and feeding turtles. The implementation of this limited-use zone has been established in collaboration with the local communities participating in our sustainable livelihoods aquaculture project, demonstrating their commitment to marine stewardship. The next phase of the project is to establish no-take areas within these protected zones.