In light of the recent marine oil spill that occurred off the coast of Mauritius (Indian Ocean), we comment here the incident, the containment method used by the local population, the biological impact of oil spill on two sensitive tropical marine ecosystems (coral reefs and mangrove forests), and we suggest monitoring and restoration techniques of the impacted ecosystems based on recent research advancements.

Mangrove forests are one of the most important biological, ecological and economic ecosystems in the world. In the Maldives, they play a crucial role in maintaining coastal biodiversity, providing ecosystem services, such as coastal protection, and supporting livelihoods by providing income and food. Overall, 23 Maldivian islands have at least 1 protected mangrove area. However, knowledge of the mangroves of the Maldives is scarce, scattered and sometimes conflicting. There is a lack of information on a national scale regarding their distribution, diversity, ecological importance and associated biodiversity. The aim of this review is to analyse scientific publications, reports, and online documents on mangroves for the entire Maldivian archipelago to provide the first comprehensive summary of the current state of knowledge of mangroves from a national perspective. This includes the geographical location of mangrove forests, the identity and distribution of mangrove species, ecosystem services, ecological importance and diversity of mangrove-associated flora and fauna. We analysed available information from both the grey literature and scientific publications and found that 14 mangrove species have been documented on 108 islands (9% of all Maldivian islands). Mangroves are mainly concentrated in northern atolls and are associated with diverse flora and fauna. Furthermore, we identified inconsistencies and gaps in the literature and proposed future directions for research. This is crucial for informed decision-making, developing effective conservation strategies and long-term sustainability of mangrove ecosystems.

Coral reefs face escalating threats from rising sea temperatures, triggering widespread mass bleaching and mortality events. Thermal preconditioning, a process in which corals exposed to sublethal thermal stress become more tolerant to subsequent thermal stress, is increasingly recognised as a promising strategy for restoration purposes. However, its underlying mechanisms remain unclear. Furthermore, species-specific responses to thermal preconditioning must be understood to ensure its broad applicability. In this study, we conducted a comprehensive multi-molecular biomarker analysis to investigate the physiological and molecular effects of thermal preconditioning on two coral species, Pocillopora damicornis and Stylophora pistillata, by exposing them to a sublethal thermal stress of + 3 °C above ambient temperature, followed by an acute stress of 32 °C (+ 8 °C). In both species, preconditioned corals showed delayed bleaching, maintaining chlorophyll a and c2 concentrations, along with Symbiodiniaceae density, for longer periods compared to non-preconditioned corals. At the molecular level, this increased thermal tolerance could be linked to the higher activity of antioxidant enzymes measured, suggesting enhanced protection against oxidative stress and consequently lower levels of lipid peroxidation (LPO) damage. Preconditioned corals also exhibited a slower downregulation of Hsp70 or sustained Hsp70 expression above basal levels during acute heat stress, possibly reflecting prolonged cellular homeostasis. Additionally, they demonstrated delayed or reduced hsp70 gene expression, indicating a less immediate response to thermal stress. Furthermore, the acquired thermal tolerance lasted longer in P. damicornis, highlighting a species-specific response to thermal preconditioning. Our study provides crucial molecular insights into the complex mechanisms of thermal preconditioning, which will be essential for developing more effective and species-targeted preconditioning protocols for practical application in coral reef restoration efforts.