Search Results (3)

The genus Pavona includes massive to submassive hermatypic corals and represents one of the main reef builders of the coral reefs in the Eastern Tropical Pacific (ETP). However, its development and specific ecological role, particularly on offshore reefs (e.g., oceanic Atolls), remain poorly understood. This study aims to determine the sclerochronological characteristics of the four Pavona species (Pavona duerdeni, Pavona clavus, Pavona maldivensis, and Pavona varians) in Clipperton Atoll, and their contributions to reef maintenance. Using the optical densitometry technique, Pavona annual growth parameters were obtained, showing that skeletal density (1.26 ± 0.23 g cm⁻³), extension rate (0.94 ± 0.31 cm year⁻¹), and calcification rate (1.17 ± 0.36 g cm⁻² year⁻¹) were consistent with previous data from the ETP. However, differences at the species level showed that P. duerdeni, P. varians, and P. maldivensis invested their calcification resources into building denser skeletons, demonstrating the morphological plasticity of the genus, likely driven by local factors, such as strong hydrodynamics and depth, rather than regional conditions (e.g., El Niño-Southern Oscillation events). Pavona’s growth strategies contribute to the preservation potential on a geological timescale of Clipperton Atoll, highlighting their importance as one of the main reef builders at a massive coral-dominated reef. Full article

Coral reefs are increasingly impacted by marine heatwaves and global warming, with the 2023–2024 El Niño–Southern Oscillation (ENSO) event causing unprecedented thermal stress across the Eastern Tropical Pacific. This study assessed the effects of this event on coral reefs in the Gulf of Papagayo, Costa Rica. Sea surface temperatures exceeded the bleaching threshold for seven months, reaching a record 10.2 Degree Heating Weeks—twice the levels recorded during the 1997–1998 ENSO. Benthic and fish community surveys revealed severe coral mortality, particularly in Pocillopora-dominated reefs, with some sites losing over 90% of live coral cover. Resilience varied across sites, likely influenced by factors such as local water circulation, coral genetic diversity, symbiont type, and heterotrophic capacity. Reefs with higher genetic diversity and thermally tolerant Durusdinium symbionts showed partial recovery. Seasonal upwelling appeared to buffer thermal stress in some areas, potentially acting as a natural climate refuge. Bleaching also impacted reef fish communities, with a notable decline in invertebrate-feeding species on degraded reefs. These findings highlight the interplay between prolonged thermal stress, coral biology, and local oceanographic processes in shaping reef resilience. Identifying and protecting such climate refugia will be critical for coral conservation under future climate change scenarios. Full article

Coral reef ecosystems are continuously degraded by anthropogenic and climate change drivers, causing a widespread decline in reef biodiversity and associated goods and services. In response, active restoration methodologies and practices have been developed globally to compensate for losses due to reef degradation. Yet, most activities employ the gardening concept that uses coral nurseries, and are centered in easily-accessible reefs, with existing infrastructure, and impractical for coral reefs in remote locations. Here we evaluate the effectiveness of direct outplanting of coral micro-fragments (Pavona clavus and Pocillopora spp.) as a novel approach to restore remote reefs in the Islas Marías archipelago in the Eastern Tropical Pacific. Coral growth (height-width-tissue cover), survival percentage, extension rates (cm year⁻¹), skeletal density (g cm⁻³) and calcification rates (g cm⁻² year⁻¹) were assessed over 13 months of restoration. In spite of detrimental effects of Hurricane Willa, transplants showed a greater-than-twofold increase in all growth metrics, with ~58–61% survival rate and fast self-attachment (within ~3.9 months) for studied species, with Pocilloporids exhibiting higher extension, skeletal density, and calcification rates than Pavona. While comprehensive long-term studies are required, direct transplantation methodologies of coral micro-fragments are emerging as time-effective and affordable restoration tools to mitigate anthropogenic and climate change impacts in remote and marginal reefs. Full article