A team of African researchers has published the first comprehensive review of seagrass restoration activities across the entire coastline of Africa, warning that these vital but poorly understood underwater ecosystems could be in serious decline.
Seagrasses are flowering plants that grow in shallow coastal waters, where their bright green leaves form underwater meadows. Along the African coastline, these meadows have supported human societies for millennia, offering food, medicine, raw materials, and cultural and spiritual meaning.
Yet seagrass meadows remain among the most poorly understood ocean habitats in terms of their global distribution and status.
Prof Sophie von der Heyden from Stellenbosch University’s Department of Botany and Zoology led the review with colleagues from North, West and East African countries. The study, titled “Identifying and addressing critical gaps to accelerate seagrass restoration in Africa”, was published in the Journal of Applied Ecology.
Research lag
Von der Heyden says that while seagrass research has increased globally over the past 20 years, studies on coral reefs outnumber seagrass research by about six to one.
“Seagrass restoration is an important part of maintaining seagrass meadows as they decline globally, but seagrass restoration science is fragmented and species-specific, meaning that what works in one region cannot be applied elsewhere,” she explains.
The review provides a timely perspective on pathways to strengthen seagrass restoration efforts in Africa, in line with the United Nations Decade of Ecosystem Restoration (2021-2030) and the recognition of seagrasses as an “Essential Ocean Variable”.
The authors evaluated published seagrass restoration studies for coastal countries with known seagrass meadows. They identified that one of the largest challenges in monitoring seagrasses in Africa remains the uncertainty around the extent and area coverage for most countries.
Only four countries – Kenya, Mozambique, South Africa and Tunisia – could provide data on the loss and gain of seagrass meadows. This means that in many countries the status of seagrasses is unknown, and it is unclear whether meadows are stable or declining.
Coastal pressure
The distribution of seagrass meadows in Africa coincides with a large coastal population of more than 250 million people, with substantial increases in the number of people living within 50 kilometres of the coastline since 2010. Coupled with regional climate change and other pressures, Africa’s seagrass meadows could be in serious decline.
The review highlighted examples of seagrass restoration trials confined to only six countries: Mozambique, Kenya, South Africa, Tanzania, The Gambia and Tunisia. A diverse set of restoration techniques has been trialed, with some proving more successful than others.
“The small number of trials and different outcomes means that we are a long way off from really knowing what works for African seagrass restoration,” Von der Heyden says.
Path forward
The authors make several recommendations to address the knowledge gaps identified. These include technological advances in remote sensing and artificial intelligence to measure the extent and dynamics of meadows, urgently identifying and limiting the drivers of seagrass loss, and exploring opportunities for large-scale restoration.
Other recommendations include building a culture of stewardship to support conservation initiatives and local livelihoods, as these meadows sustain local economies such as small-scale fisheries and participation in the blue economy through initiatives such as carbon credit projects.
“However, we need the political will, secure funding and the buy-in from multiple stakeholders, such as communities living next to seagrass meadows, to ensure meaningful restoration of African seagrass meadows,” Von der Heyden warns.
The authors call for the immediate targeted protection of remaining seagrass meadows in Africa: “Protecting extant meadows not only continues to provide benefits to nature and people but offers opportunities for the cultivation of plant material for future restoration efforts.”
Around the world, seagrass meadows are under threat. Protecting and restoring them is one of the best ways to support both people and planet, the authors conclude.
