Growth and carrying-capacity trials, community monitoring of seagrass and sandfish, and social and environmental baselines guide how each site is stocked and managed. We welcome independent researchers who want to study the outcomes with us.
Published research and reports the model draws on. Links go to the DOI.
| Theme | Key Finding | Source |
|---|---|---|
| Seagrass growth enhancement | Farming H. scabra at production stocking density increased the leaf growth of the seagrass Thalassia hemprichii. Village-scale field experiment, southwest Madagascar. | Arnull, Wilson, Brayne, Dexter, Donah, Gough, Klückow, Ngwenya & Tudhope, Aquaculture Environment Interactions 13:301–310, 2021. DOI → |
| Seagrass exclusion experiment | Biomass and growth of the seagrass Cymodocea serrulata fell when H. scabra were excluded. Two-year exclusion experiment, subtropical Queensland. | Wolkenhauer, Uthicke, Burridge, Skewes & Pitcher, J Mar Biol Assoc UK 90:215–223, 2010. DOI → |
| Seagrass–sea cucumber mutualism | Stable isotope analysis shows seagrass detritus makes up much of the diet of H. scabra in tropical seagrass meadows. | Floren, Hayashizaki, Putchakarn, Tuntiprapas & Prathep, Frontiers in Marine Science 8:696134, 2021. DOI → |
| Ecosystem functions | "Sea cucumbers excrete inorganic nitrogen and phosphorus, enhancing the productivity of benthic biota." Deposit feeders reduce organic load and rework surface sediment. "Overexploitation of sea cucumbers is likely to decrease sediment health, reduce nutrient recycling… diminish biodiversity of associated symbionts, and reduce the transfer of organic matter from detritus to higher trophic levels." | Purcell, Conand, Uthicke & Byrne, Oceanography & Marine Biology: An Annual Review 54:367–386, 2016. DOI → |
| Coral disease suppression | Removing sea cucumbers from around corals increased coral tissue and colony mortality. "Historic overharvesting of sea cucumbers increases coral disease and threatens the persistence of tropical reefs." | Clements, Pratte, Stewart & Hay, Nature Communications 15:1338, 2024. DOI → |
| Ocean acidification buffering | Sea cucumber digestive processes account for a significant share of night-time carbonate dissolution on a reef flat, with a buffering effect on local seawater chemistry. | Schneider, Silverman, Woolsey, Eriksson, Byrne & Caldeira, JGR: Biogeosciences 116, G04018, 2011. DOI → |
| Ranching / restocking pathway | Restocking, stock enhancement and sea ranching with hatchery-reared juveniles are routes to restore overexploited sea cucumber populations. | Bell, Purcell & Nash, Ocean & Coastal Management 51(8-9):573–584, 2008. DOI → |
| Sandfish farming in Zanzibar | Sandfish farming in Zanzibar has been held back by scarce juveniles and by poaching; the authors call for hatcheries and community by-laws. | Charisiadou et al., Aquaculture, 2022. DOI → |
| Pemba seascape baseline | Ecological and socioeconomic baseline for the Pemba East Marine Conservation Areas. "Conservation initiatives cannot succeed in isolation from livelihood needs… ecological protection and improved living standards are mutually reinforcing." | Mensa, Hassan, Iswalala, Mateso, Kasuga, Taylor, Ismail & Mangora, WCS Tanzania report, 2026. DOI → |
Sandfish growth trials across different seabed types, so stocking matches what each site can support.
Cooperative members trained to survey the sandfish in their own area, giving each site its own record of the stock over time.
Quadrat surveys of the seagrass inside the closed area, carried out by trained cooperative members, to follow how the habitat responds to protection.
Each site starts with a social and environmental baseline survey. At Shamiani it used field forms in English and Kiswahili.
All of Pemba's coastline lies within gazetted Marine Conservation Areas, so every CORE Zone sits inside one. Inside that, each CORE Zone is a community hifadhi, a long-term closure the community puts forward for government recognition through its Shehia Fishers Committee.
We intend to support the Revolutionary Government of Zanzibar in recognising CORE Zones as Other Effective Area-based Conservation Measures (OECMs), which count toward the global 30×30 target.