Evidence brief: A review of coral reef restoration initiatives in the Western Indian Ocean Region

Abstract

Widespread coral reef degradation in the Western Indian Ocean (WIO) underscores the need to support restoration to accelerate recovery in severely impacted areas. Restoration science in the WIO remains nascent, with few small-scale initiatives and limited integration between reef managers, practitioners, and researchers, hindering effective coordination of efforts toward larger-scale action. This study aimed to consolidate knowledge on WIO coral restoration initiatives, identify lessons learned, and assess current practices to inform future coordination and scaling efforts. We focused on (i) approaches and techniques used, (ii) lessons from successes and failures, and (iii) the potential role of a regional practitioner network in addressing identified gaps. Data were compiled from peer-reviewed literature, online sources, a WIO practitioner survey, and a regional workshop. Results indicate growing momentum for coral reef restoration, particularly in Kenya, Tanzania, and the Seychelles, with an increase in publications since 2021. Twenty-two active initiatives were identified across eight countries; 76% involved local communities, and 27% were fully community-led. Asexual methods like coral gardening dominated due to cost-effectiveness, while sexual propagation was limited to Seychelles and planned for Mauritius. Initiatives primarily targeted fast-growing genera such as Acropora and Pocillopora, with limited species diversity. Monitoring practices were highly variable, with most projects relying on short-term ecological indicators and few reporting standardized quantitative metrics such as survival rates or restoration footprint. While 86% of projects collected ecological baseline data, only 38% included socio-economic indicators. The synthesis of findings contributed to the establishment of the Western Indian Ocean Coral Reef Restoration Network (WIOCRRN), a regional platform guided by the Capacity, Access, Research, and Enhancement (“CARE”) framework, aimed at advancing resilient and sustainable reef ecosystems while aligning conservation outcomes with the socio-economic needs of coastal communities. The uneven geographic distribution of initiatives and documented data gaps highlight opportunities for improved coordination, standardization, and strategic scaling of restoration efforts across the region.

1.0. Introduction

The Western Indian Ocean (WIO) region; encompassing Kenya, Comoros, Seychelles, Mauritius, Madagascar, Tanzania, Mozambique, Somalia, South Africa, Mayotte, and Réunion, is home to approximately 10% of the world’s coral reefs and is recognized as a global biodiversity hotspot, hosting one of the highest concentrations of coral species outside the Coral Triangle [1]. These reefs contribute significantly to national economies, with millions of people in coastal communities depending on them for fisheries, tourism, and coastal protection [1,2]. Coral reefs in the WIO have experienced widespread degradation driven by recurrent marine heatwaves, coastal development, overfishing, and declining water quality, with recent assessments reporting substantial losses in live coral cover across multiple countries [1,3,4]. Despite their ecological and socio-economic importance, restoration and recovery efforts in the region remain limited in scale and unevenly documented, particularly when compared to more intensively studied regions such as the Caribbean and Pacific [5].