Vanuatu's Customary 'Tabu' Marine Closures — Village-Led Reef Recovery Under Kastom Law

In Vanuatu, temporary or permanent bans on harvesting called 'tabu' are imposed by customary landowners under kastom (traditional) law, and are the most widely used community-based fisheries management tool in the country. Since 2014 the Fisheries Act has formally required consultation with customary marine-tenure holders before new marine reserves are declared, and the 2002 Environmental Management and Conservation Act gives legal recognition to community conservation areas — building state law on top of a governance system that predates it by generations.
At Takara village on North Efate, a 0.2 km2 village-based marine reserve (VBMR) was established in 2008 over fringing reef habitat for the topshell Tectus (Trochus) niloticus, a heavily harvested species. A peer-reviewed study published in PLOS One in 2017, based on tagging 100 adult trochus and repeated density surveys, found biomass thirteen-fold higher and harvestable density ten-fold higher in the reserve's southern zone compared with the northern zone, with protected individuals 25% larger on average — but at the scale of the whole reserve, three years of closure showed no statistically significant protection effect, showing how localised and patchy these gains can be.
On Emau island, a 2010 study in Environmental Conservation compared two small tabu areas (each under 0.05 km2) of different ages. The older, larger tabu produced a strong positive abundance and size response for trochus, helped by community-led translocation of animals into the reserve. Giant clams (Tridacna spp.) showed smaller gains that were not statistically significant after four years of closure, and green snail (Turbo marmoratus) stocks remained severely depleted despite protection — an honest signal that small customary closures work well for some species and poorly for others.
The evidence base is real but mixed: tabu areas reliably help fast-recovering, sedentary species like trochus at local scale, while slower-recovering species and reserve-wide effects are less consistent. Their durability comes less from ecological guarantees than from social legitimacy — because the rules are set and enforced by the customary owners themselves, they tend to outlast externally funded conservation projects.
Read more: https://pmc.ncbi.nlm.nih.gov/articles/PMC5413025/

Read the full analysis: https://www.cambridge.org/core/journals/environmental-conservation/article/abs/effectiveness-of-villagebased-marine-reserves-on-reef-invertebrates-in-emau-vanuatu/50A9317E82319F57AB1494E5DF3FA82F