Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Introduction: Coral reef structures in Zihuatanejo, Guerrero are well-preserved. The coverage of living corals, near 60 % at several locations, makes them comparable to other coral reefs in the states of Oaxaca, Jalisco, and Nayarit and with high potential to promote their conservation. Objective: To present the outcome of 12 years of research in coral communities from Zihuatanejo, Guerrero, as a justifying argument for the current conservation efforts in the area. Methods: We developed a baseline on the conservation status of the reef structures, bioerosion processes and the source of major natural and anthropogenic impacts. We assessed the genetic diversity of the coral zooxanthellae symbionts, the outcome of a technique of coral transplantation to recover the coverage of living corals and the local ecological knowledge to involve local inhabitants to promote conservation. Results: At least five coral reefs remain exposed to a medium-low level of impact by bioerosion and anthropization. Coral transplantation experiments made in the area showed records of transplant survival nearing 90 %. Although the warming of the sea surface temperature that occurred during the El Niño of 2015-2016 caused coral bleaching and mortality in several coral populations in this area, there were no affectations attributed to this phenomenon in other locations. This response was not related to the level of exposure to anthropogenic impacts, and the presence of thermal resistant zooxanthellae was assessed using molecular tools, confirming the existence of zooxanthellae of the genus Durusdinium. The analysis of local ecological knowledge of the inhabitants of Zihuatanejo showed that they keep elaborate knowledge on the ecology of coral reefs. This is complemented with scientific knowledge that will encourage community participation in conservation strategies. Conclusions: A long-term multidisciplinary strategy is required for coral reef conservation that encompasses: 1) assessing the role of the overall holobiont in the thermal resistance of corals from this area and 2) establishing restoration strategies of coral reefs that include the local knowledge about marine ecology, for the establishment of coral reef protection and management schemes put in place by local inhabitants.

Introduction: Populations of the coral Orbicella annularis have shown low recruitment in the Caribbean. One of the demographic bottlenecks is the high mortality in the early stages of development. Detailed knowledge of the cycle and survival rates of these phases will allow us to assist in population recovery and reef restoration. Objective: To describe the embryogenesis and larval stages obtained by assisted fertilization and measure the settlement and survival rates of larvae on artificial substrates, before being outplanted to the reef. Methods: Six days after the full moon in September 2021, gamete bundles were collected from eight O. annularis colonies in Los Corales del Rosario and San Bernardo National Natural Park, Colombia and brought to the laboratory. Cross fertilization was carried out and embryonic and larval development were followed until larval settlement and survival was recorded until day 41. The larvae were kept in three tanks with filtered sea water with 126 tagged substrates, previously conditioned with crustose coralline algae. The substrates were then outplanted to the reef. Results: The onset of embryonic development occurred 1.11 hAF (hours after fertilization), when cells showed signs of the first cleavage, and lasted until 104.59 hAF when they began to metamorphose. Larvae settlement was observed on the sixth day AF. Twenty-one days after fertilization, zooxanthellae were found. Post-settlement larval survival was 27.5 %. Conclusions: In this first sexual propagation effort using O. annularis in Colombia, 1.4 % of competent larvae completed the entire development process. Although low survival rate, these results add to coral restoration efforts in the Caribbean in which species are assisted to increase the survival of corals in their early stages of development.

Introduction: The branching coral Pocillopora is the main reef-building species in the Eastern Tropical Pacific (ETP) region. However, their populations have been threatened due to the intense effect of thermal-stress events in the last three decades. As a mitigating response, active restoration strategies have been developed. However, it has not been possible to establish specific protocols along the ETP’s reefs. Objective: To evaluate the efficiency of two different substrates (natural vs. artificial), through coral growth comparison (extension rate and tissue area) in three Pocillopora coral morphospecies within a year. Methods: Coral growth was estimated by two techniques: extension rate and tissue area of P. cf. verrucosa, P. cf. capitata, and P. cf. damicornis every three months during a year. Results: The extension rate and superficial area growth vary among the coral morphospecies P. cf. verrucosa (16.33 mm yr-1 and 168.49 mm2 yr-1), P. cf. capitata (16.25 mm yr-1 and 176.83 mm2 yr-1), and P. cf. damicornis (12.38 mm yr-1 and 87.62 mm2 yr-1). The data reveals that substrate type did not affect Pocillopora growth, yet there was an effect caused by seasonal changes. Conclusions: This study demonstrates that coral restoration can be implemented using both natural and artificial substrata, with no differences in coral growth. We recommend the implementation of coral reef restoration programs, highlighting the importance of initiate during the warm season due to optimal growth performance of P. cf. verrucosa and P. cf capitata species, which improves the effectiveness of management actions in Isla Isabel National Park.

Introduction: Hermatypic corals have the capacity to construct the physical reef-framework and maintain the balance of coral reef functionality. However, in the past three decades, coral communities have been menaced by natural and anthropic pressures, resulting in an abrupt coral cover decline, and slow natural recovery.  To mitigate coral reef collapse, assisted restoration techniques has been implemented and improved worldwide, However, the long-term effects of such interventions on ecological attributes have been scarcely reported.  Objective: This study evaluated the effect of assisted coral intervention on calcium carbonate production (kg CaCO3 m-2 yr-1) and ecological volume (cm3) yielded by branching and massive corals from the central Mexican Pacific.  Methods: We used colony size, extension rate, and skeletal density measurements of direct outplanted Pocillopora and Pavona coral species to calculate coral carbonate production, ecological volume, and model their long-term potential.  Results: Coral carbonate produced after one-year of outplanting increased by 42 % (1.17 kg CaCO3 m-2 yr-1), where Pocillopora spp. and Pavona clavus corals contribute with 0.97 and 0.20 kg CaCO3 m-2 yr-1, respectively. The ecological volume also increased by 384 cm3 for Pocillopora and 56 cm3 for Pavona after one year period. Furthermore, the results suggest that long-term coral restoration actions (10 years) have the potential to significantly increase carbonate production.  Conclusions: our data indicate that coral restoration initiatives have the potential to help mitigate the current low calcium carbonate production of Mexican Pacific reefs and may significantly contribute to the long-term maintenance of reef-framework based on ecological engineering tools, such initiatives represent essential functional properties related to reef ecosystem services provision.

Introduction: The 1997-98 El Niño event caused massive coral bleaching and mortality in the Central Mexican Pacific (CMP). Punta de Mita alone used to harbor more than 30 % of the coral coverage in this region, with a mono-specific Pocillopora coverage. The 1997-1998 ENSO event caused massive coral mortality reducing live coral coverage to < 5 %.  Despite being considered a coral region unlikely to recover, recent restoration efforts have been implemented to rehabilitate the coral community. Objective: To assess coral recovery by analyzing the coral growth and survival rates of branching Pocillopora species at Punta de Mita. Methods: Healthy coral fragments of opportunity were re-attached to the natural substrata using zip ties and measured considering their growth in terms of maximum length and width (cm) to determine their annual extension rates. Results: After 50 weeks, corals duplicated their size, with a mean growth of ~ 4 cm year-1. After 100 weeks (2 years), corals triplicated their size, increasing on average 8–9 cm in each diameter. Conclusions: Successful coral reef restoration activities in the Central Mexican Pacific are the result of Pocillopora’s physiological processes, such as fast growth rates, and recent life-history traits, like the ability to cope with thermal anomalies, which enable them to thrive in a dynamic region severely affected by natural and anthropogenic perturbations. Indeed, a region considered unlikely to recover has regained its live coral cover from < 5 % in 1998 up to 15 % in 20 years. This demonstrates the importance of assisting natural coral recovery with restoration efforts, especially in coral locations that, despite environmental perturbations, have proven to be resilient and may become coral refugia areas under the current climate change scenario.

Introduction: Global coral bleaching reflects coral fragility to adverse environmental conditions and climate change. Porites lobata is the most abundant hermatypic coral species currently in El Salvador and has experienced recent bleaching events at natural protected area Complejo Los Cóbanos. Objective: To describe the bleaching episodes that colonies of P. lobata experienced at Los Cóbanos, El Salvador, during the last 18 years, and analyze coral restoration efforts. Methods: Approximately 2 100 images (2006 – 2022) taken without specific periodicity from two sites were reviewed. Water parameters since 2014 were registered without defined frequency. The areas sampled were El Faro beach and subtidal colonies near an important beach resort. The first area presented dispersed colonies on an intertidal zone, the other, larger colonies at 2 m deep in low tide. Also, literature about activities to restore reefs within the country was reviewed. Results: Several bleaching events occurred during this observation period. Some of them could be associated to high sea water temperatures (> 30 o C) from May to October (rainy season), others to harmful algae blooms, as well as unknown causes. Severe bleaching that caused loss of coral coverage on intertidal colonies occurred during the global event (2015-2016). Conclusion:  Bleaching at Los Cóbanos occurs in different intensity patterns usually during the rainy season that encompasses high temperature and turbidity levels in water, as well as algal blooms. The 2015-2016 episode caused coral coverage loss on the intertidal colonies and subtidal ones experienced little permanent damages (< 5% mortality). National restoration policies for coral colonies require more strategic efforts considering the local littoral hydrodynamics and institutional capabilities.

Introduction: The fireworm Hermodice carunculata is a widespread polychaete that can prey upon many coral species. However, few studies have examined the effect of fireworm predation on coral demographics during non-outbreak periods.  Objective: To determine whether predation by H. carunculata compromised the growth, survival, and population performance of the threatened coral Acropora cervicornis.  Methods: Nursery-reared coral fragments (n = 99) were fixed to the bottom of Punta Melones reef in the Island Municipality of Culebra, Puerto Rico. Predation activity and its demographic consequences on coral outplants were assessed from December 2020 to August 2022. Susceptibility to predation was compared between colonies collected directly from the reef and those originating from outside sources (e.g., coral nurseries). With the demographic data, simple size-based population matrix models were developed to 1) examine whether fireworm predation led to a significant decline in population growth rate (λ), 2) determine the demographic transition(s) that contribute the most to λ, and 3) determining the demographic transition(s) that accounted for differences in λ when comparing scenarios that considered either only predated colonies or both predated and non-predated outplants.  Results: Predation increased over time, being more frequently observed in the area with the highest topographic relief and on colonies foreign to the study site. Outplants that were partially consumed grew significantly slower than non-predated colonies; however, predation did not threaten their survival. The likelihood of being attacked by the fireworm increased with branching complexity. The estimated λ for a scenario considering only those predated colonies was 0.99, whereas, for a scenario where both predated and non-predated colonies were considered, λ was 0.91. Population growth, under both scenarios, was mainly influenced by the probability of a large colony surviving and remaining at the largest size.  Conclusions: Although predation can negatively impact coral growth, the relatively high survival rate of predated colonies compensates for the adverse effects. Since survival is the demographic transition that contributes most to population growth, it could be concluded that under a non-outbreak scenario, fireworm predation may not be the primary cause of A. cervicornis population decline.

Introduction: One of the main bottlenecks in restoration projects based on sexual reproduction is post-settlement survival, mainly due to competition for substrate with fleshy algae and predation. Therefore, substrates of different shapes and materials have been created and tested, seeking to optimize these processes with attractive surfaces for the larvae and structures where the recruits are protected from predation, and competition is reduced.  Objective: To improve settlement and post-settlement survival of two important Caribbean reef-building corals, using different coatings on substrates.  Methods: To determine whether substrate coatings properties are favourable to larval settlement in Orbicella annularis, and O. faveolata, collected in Puerto Morelos, Mexican Caribbean, we evaluated their settlement for three weeks on six coatings with a combination of properties. Each coating was designed to provide a combination of two out of three properties: 1) water repellence (hydrophobicity), 2) phosphorescence-based colour, and 3) mineral-enriched surface chemistry. In a separate experiment larvae settlement was tested using coatings with a single property. Finally, we determined the post-settlement survival of O. annularis and O. faveolata on the different coatings for seven weeks.  Results: The combination of high hydrophobicity and light blue phosphorescent microparticles and high hydrophobicity and red-orange phosphorescent microparticles resulted in a higher settlement of O. annularis and O. faveolata when compared with other coatings (30.8 - 66.7 % higher). No significant differences were found in the number of larval settled when the water-repellence and the phosphorescence-based were evaluated independently. Post-settlement survival time on substrates was low, with a maximum of 34 days after settlement for O. annularis and 42 days for O. faveolata.  Conclusions: In terms of the larval settlement, the combination of the coatings properties appears to play an essential role in the choice of microhabitat for both O. annularis and O. faveolata. But individually these properties did not generate an advantage in the larval settlement. Moreover, some chemical components associated with the coatings may be counterproductive to the survival of the polyps over time.

Introduction: Coral reefs are highly degraded ecosystems, for which it has been necessary to implement active restoration actions to recover their structure and functioning. Asexual propagation has been implemented to obtain small fragments (~10 cm) from the distal branches of donor colonies of corals of the species Acropora palmata, to subsequently relocate them in the reef substrate, simulating the dispersion effect that occurs naturally in the species, which in this work is called assisted propagation. However, it is necessary to evaluate the effects of this technique, such as the number of fragments that can be obtained from each colony, the tissue recovery period of the donor colonies and fragments.  Objective: To address the effect of pruning on donor colonies by estimating the percentage of live tissue removed from donor colonies of A. palmata and their recovery rate after 30-months.  Methods: Four surveys were carried out: before, immediately after pruning, one month after outplanting, and 30 months after pruning on four colonies of A. palmata located in the Parque Nacional Costa Occidental de Isla Mujeres, Punta Cancún and Punta Nizuc in the Mexican Caribbean. Photogrammetry-based 3D modeling was performed using Agisoft Metashape Pro software, while tissue surface area, radial and apical growth were obtained using CloudCompare software.  Results: After fragment collection, the material used in the assisted propagation represents less than 12% of the living tissue. After one month, the donor colonies showed a recovery of 5%, with new tissue covering the cut areas. The donor colonies lost on average 65 % of living tissue after four hurricanes, and in one case the colony was lost all together, but with the outplanted fragments the genotype could be preserved.  Conclusions: Assisted propagation could increase living tissue of branching corals in relatively short intervals of time, without serious damage to the donor colony if less than 12 % is removed.

Introduction: Coral- reef communities are considered one of the most biodiverse, but also most threatened, marine ecosystems, and the accelerating loss of habitat over the past decades warrants active intervention.  Objective: The present study demonstrates the successful implementation of a low-impact restoration technique in three Central Mexican Pacific degraded coral communities, using a protocol based on natural fragmentation (“fragments of opportunity”) of the branching coral Pocillopora spp., considered the most abundant and primary carbonate-producing coral species of the Eastern Tropical Pacific.  Methods: The restoration program was implemented in two offshore and one inshore coraline areas. The relationships between seawater temperature and coral survival, growth, and attachment rate were assessed over one year, with 183 fragments monitored each month.  Results: The mean coral growth rate was 3.3 ± 0.1 mm mo-1, with annual growth rates in length and width of 39.9 ± 14.2 and 36.5 ± 19.5 mm yr-1, respectively. Self-attachment efficiency was 78 % and the survival rate was high (84 %). The growth rate differed significantly among reefs.  Conclusions: Upon monitoring directly fragmented corals over a year, growth rates were deemed high enough to merit active restoration in the region. However, our data show that structural and abiotic differences and seasonal variability must be considered overall in successful long-term coral community restoration initiatives in the eastern Pacific region.