Zanzibar Reef Restoration: Coral reefs are the rainforests of the sea. These critically important ecosystems host more than 25% of all marine life. Climate change, and pollution from human sources, are destroying these reefs at an alarming rate worldwide.
In addition to the effect on the marine environment, a decline in live coral cover also poses a significant threat to local livelihoods, food security, commercial and subsistence fisheries, tourism, and associated industries. In Zanzibar, local efforts are underway to address this problem in a way that could be replicated around the globe.
The pressures on Zanzibar’s coral reefs mirror those facing all such reefs around the world: increasing water temperatures resulting from climate change, tropical cyclones, destructive fishing practices, plastic waste, unregulated tourism, and unrestricted coastal development.
In September 2021, the “Oceans Without Borders” Mnemba Island Community & Conservation Team started an intensive and comprehensive training course with Marine Cultures, an NGO supporting small-scale ecological aquaculture conservation projects in Zanzibar.
They are working to restore the ecological integrity of the local Mnemba Island reefs, assist in the management and protection of this marine conservation area, and ultimately support the sustainability of local reef fisheries.
The Mnemba House Reef was selected as a living laboratory for the project. Large underwater coral-nursery tables, rather like similar nursery tables in greenhouses on land, have been set up to cultivate coral fragments. Initially, five tables were constructed. There are now 42 tables.
The first coral colonies grown in this flourishing coral nursery were then transplanted onto degraded sections of the local house reef. However, these transplants had to be protected, so the local people constructed metal-framed cages, and weighed them down with rocks, to provide a stable growth environment. The photo below is a “turtle-shaped” construct, but “Starfish” constructs have also been developed.
To ensure biodiversity and genetic integrity, clusters of 4 – 5 pieces will be transplanted together onto different reef sections. To date, 7,193 micro-colonies have been transplanted onto degraded sections of the Mnemba Island House Reef.
In the expansion phase of this restoration project, other artificial reef structure sites have been established in collaboration with island communities. These new artificial reefs remain within the Mnemba Island Marine Conservation Area (MIMCA), which allows for the local communities to still receive revenue generated from tourists on day trips that visit the reef.
The way ahead for this project holds the promise of a far-reaching legacy of research, education and new opportunities within the marine economy of Zanzibar.
“Restoring the balance” is the focus of the Oceans Without Borders’ five-year programme strategy across the Mnemba Island seascape, working in collaboration with local stakeholders and Zanzibar’s Ministry of Blue (marine) Economy & Fisheries.
January 2024 finds this team ramping up the coral nursery to accelerate the restoration the the Mnemba House Reef, developing the existing and new artificial reef sites, and conducting reef health and biodiversity monitoring at key sites, using the additional resource of “BRUVS” (Baited Remote Underwater Video Systems) on reefs deeper than 50 meters.
The group’s land initiatives include conducting regular beach erosion surveys, interactive community meetings, sharing environmental learnings with local communities, boat operators and fishermen, and, potentially, sharing their experiences and expertise with the worldwide community of coral reef preservation and restoration groups and organizations.
It’s good to report on local efforts to protect and foster the environment. Those efforts are always more focused, cost-effective and longer-term-sustainable than large government, or major corporate, based efforts.
