Identifying and addressing critical gaps to accelerate seagrass restoration in Africa

Abstract

Abstract Seagrass meadows have supported human societies for millennia, offering a tapestry of social‐ecological values that include food, medicine, raw materials, cultural and spiritual meaning. Fourteen seagrass species have been reported from 41 African countries, but their extent is largely unknown, and it is likely that many meadows on the continent experience declines. Seagrass restoration is well established globally, providing mechanisms to secure seagrass meadows and their associated benefits to biodiversity and humanity, but restoration science remains globally uneven. We review the state of knowledge of actively restoring seagrass meadows in Africa, including target species, restoration approaches, monitoring times, and restoration outcomes. The first African seagrass restoration trials were documented in 2007, but restoration approaches and outcomes have only been formally reported since 2020. Only six countries have documented some form of restoration trials (Mozambique, Kenya, South Africa, Tanzania, The Gambia, Tunisia) that incorporate nine species ( Cymodocea nodosa , Halodule wrightii , Halodule uninervis , Oceana serrulata , Posidonia oceanica , Thalassodendron ciliatum , Thalassia hemprichii , Syringodium isoetifolium , Zostera capensis ). Restoration has primarily used cores as donor material, with seed‐based (including anchoring with Hessian sacks) or nursery‐propagation methods not well explored. Trials have been at small scales (generally <300 m 2 ) and monitoring activities lasted for <18 months. There was no consistent approach to carrying out trials, or monitoring restoration outcomes between studies. Synthesis and application : Seagrass restoration science in Africa is highly regionalised and fragmented and approaches inconsistent, highlighting the need for more unified and standardised approaches to restoration trials. However, current gaps in knowledge provide exciting opportunities, that when addressed will strengthen seagrass restoration science and capacity. These include building on technological advances in remote sensing and artificial intelligence to measure extent and dynamics of meadows, identifying and limiting drivers of seagrass loss and exploring opportunities for large‐scale restoration. Remaining meadows require immediate protection and regional climate change scenarios need to be considered in restoration planning, with targeted, long‐term investment and collaboration and stronger policies on ecological restoration essential. Building science–citizen partnerships, strengthening seagrass custodianship and investigating the value and perceptions of seagrass to society are all crucial aspects of ‘societies for seagrass’ and securing African seagrass meadows into the future.