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Introducción: En Panamá y el mundo, desde hace varios años, los arrecifes se han visto amenazados por acciones como el desarrollo costero, sedimentación, contaminación por entidades terrestres, que son las más frecuentes, dando lugar a la implementación de metodologías de restauración. Objetivo: Comparar la eficiencia de dos estructuras de jardines coralinos en el crecimiento de la especie Acropora cervicornis en Bahía Huertas, Parque Nacional Portobelo, Colón Panamá. Métodos: Se colocaron dos estructuras de tipo fijo, utilizando PVC junto con bases de concreto hidráulico, y dos estructuras tipo tendedero, utilizando PVC e hilo de nylon. Los fragmentos de coral que se colocaron en las estructuras provenían de Bahía Huertas e Isla Buenaventura. El crecimiento de los corales se determinó mediante el método de medición de crecimiento lineal y extensión tisular. Resultados: Se plantaron un total de 80 fragmentos de coral, lo que representa una extensión estimada de 9.71 m de coral en Bahía Huertas. Tras nueve meses de estudio, se estimó un total de 15.3 m de coral totalmente nuevo (1 525.6 cm), donde sólo el 4.6 % pertenecía a los fragmentos de la estructura de tipo fijo, mientras que el 95.4 % pertenecía a la estructura de tipo tendedero. Conclusiones: La estructura tipo tendedero fue la más eficiente y viable dentro del estudio, con mejor tasa de supervivencia y crecimiento en comparación con la estructura tipo fija, donde sí presentó una mortalidad del 45 %.

Introduction: In Panama and the world, for several years, reefs have been threatened by actions such as coastal development, sedimentation, and contamination by terrestrial entities, which are the most frequent, giving rise to the implementation of restoration methodologies. Objective: To compare the efficiency of two coral garden structures in the growth of the species Acropora cervicornis in Huertas Bay, Portobelo National Park, Colon Panama. Methods: Two fixed-type structures were placed, using PVC together with hydraulic concrete bases, and two clothesline-type structures, using PVC and nylon thread. The coral fragments that were placed in the structures came from Bahía Huertas and Buenaventura Island. The growth of the corals was determined using the linear growth and tissue extension measurement method. Results: A total of 80 coral fragments were planted, representing an estimated extension of 9.71 m of coral in Huertas Bay. After nine months of study, a total of 15.3 m of totally new coral (1 525.6 cm) was estimated, where only 4.6 % belonged to the fragments of the fixe-type structure, while 95.4 % belonged to the clothesline-type structure. Conclusions: The clothesline-type structure was the most efficient and viable within the study, with better survival and growth rate compared to the fixed type structure, where it did present a mortality of 45 %.

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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.

Introducción: El evento El Niño de 1997-98 causó un blanqueamiento y mortalidad masiva de corales en el Pacífico Central Mexicano (CMP). Solo Punta de Mita albergaba más del 30 % de la cobertura coralina de esta región, con una cobertura monoespecífica de Pocillopora. El evento ENSO de 1997-1998 causó una mortalidad masiva de corales que redujo la cobertura de corales vivos a < 5 %. A pesar de ser considerada una región de coral con pocas probabilidades de recuperarse, se han implementado esfuerzos de restauración recientes para rehabilitar la comunidad coralina. Objetivo: Evaluar la recuperación de coral analizando el crecimiento coralino y las tasas de supervivencia de especies ramificadas de Pocillopora en Punta de Mita. Métodos: Fragmentos de oportunidad de coral sanos se volvieron a unir a los sustratos naturales usando bridas y se midieron considerando su crecimiento en términos de longitud y ancho máximos (cm) para determinar sus tasas de extensión anual. Resultados : Después de 50 semanas, los corales duplicaron su tamaño, con un crecimiento promedio de ~ 4 cm año-1. Después de 100 semanas (2 años), los corales triplicaron su tamaño, aumentando en promedio 8-9 cm en cada diámetro. Conclusiones: Las actividades exitosas de restauración de arrecifes de coral en el Pacífico Central Mexicano son el resultado de los procesos fisiológicos de Pocillopora, tales como tasas de crecimiento rápido, y rasgos de historia de vida reciente, como la capacidad de hacer frente a anomalías térmicas, que les permiten prosperar en una región dinámica severamente afectada por perturbaciones naturales y antropogénicas. De hecho, esta región que se consideraba poco probable que se recuperara, ha recuperado su cobertura de coral vivo de < 5 % en 1998 hasta 15 % en 20 años. Esto demuestra la importancia de ayudar a la recuperación natural de los corales con los esfuerzos de restauración, especialmente en las ubicaciones de corales que, a pesar de las perturbaciones ambientales, han demostrado ser resistentes y pueden convertirse en áreas de refugio de corales ante el escenario actual de cambio climático.

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Introducción: Los arrecifes coralinos son afectados negativamente por diferentes causas antropogénicas y ambientales en el Golfo de Papagayo. Objetivo: En esta investigación, la condición del arrecife coralino de Playa Blanca fue evaluado. Métodos: Entre agosto de 2010 y setiembre de 2011 el porcentaje de coral vivo por especie y del alga Caulerpa sertularoides fue determinado; el crecimiento anual de P. damicornis y P. elegans fue medido y relacionado con variables ambientales. Resultados: Se encontraron 14 especies de corales, dos de ellas, F. curvata y L. papyracea, únicamente como esqueletos. La zona con la mayor cobertura fue en la zona media de la playa. La especie con mayor CCV en todos los ámbitos de profundidad fue P. damicornis, seguido de P. elegans. La CCV descendió de 29 % en septiembre 2010 a 1 % en octubre 2010. La mortalidad masiva fue causada por una Floración Algal Nociva (FAN). La tasa de crecimiento de P. damicornis (26.0 ± 8.9 mm año-1) y de P. elegans (27.9 ± 4.5 mm año-1), no mostraron diferencias significativas entre profundidades ni por ubicación en el arrecife. Conclusiones: El exuberante arrecife de coral de Playa Blanca experimentó una regresión repentina de la CCV similar a las descritas por Glynn et al. (1983). Esto sugiere que ocurren ciclos de mortalidad y recuperación natural de los arrecifes de coral, aunque las presiones antropogénicas reducen la capacidad de resiliencia de estos. El ordenamiento espacial, tanto en tierra como en el mar, es vital para un adecuado desarrollo humano, en el que se incorpore en el análisis el aumento de la capacidad de recuperación de los ecosistemas coralinos.

Introduction: Coral reefs are negatively affected by different anthropogenic and environmental causes in the Gulf of Papagayo, Costa Rican Pacific coast. Objective: The health status of the Playa Blanca coral reef was evaluated. Methods: Between August 2010 and September 2011, the percentage of live coral cover (LCC) per species and of the macroalgae Caulerpa sertularoides was determined in four sectors and at three depths of the coral reef; the annual growth of Pocillopora damicornis and P. elegans was measured and related to temperature, nutrients, wind, sun irradiation and rain. Results: 14 species of corals were found, two of them, Fungia curvata and Leptoseris papyracea, only as skeletons. The area with the highest LCC was offshore in the middle zone of Playa Blanca. The species with the highest coverage in all depth ranges was P. damicornis, followed by P. elegans. The LCC decreased from 29% in September 2010 to 1% in October 2010 due to a mass coral mortality caused by harmful algal blooms. The growth rate of P. damicornis (26.0 ± 8.9 mm year-1) and P. elegans (27.9 ± 4.5 mm year-1) did not show significant differences between depths or location in the reef. Conclusions: The exuberant Playa Blanca coral reef experienced a sudden drop in LCC similar to those described by Glynn et al. (1983). This suggests that cycles of mortality and natural recovery of coral reefs occur, although anthropogenic pressures reduce the resilience capacity of the reefs. Spatial planning, both on land and in the sea, is vital for adequate human development, in which the increase in the resilience of coral ecosystems is incorporated into the analysis.

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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.

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Corals of the eastern tropical Pacific live in a marginal and oceanographically dynamic environment. Along the Pacific coast of Panamá, stronger seasonal upwelling in the Gulf of Panamá in the east transitions to weaker upwelling in the Gulf of Chiriquí in the west, resulting in complex regional oceanographic conditions that drive differential coral-reef growth. Over millennial timescales, reefs in the Gulf of Chiriquí recovered more quickly from climatic disturbances compared with reefs in the Gulf of Panamá. In recent decades, corals in the Gulf of Chiriquí have also had higher growth rates than in the Gulf of Panamá. As the ocean continues to warm, however, conditions could shift to favor the growth of corals in the Gulf of Panamá, where upwelling may confer protection from high-temperature anomalies. Here we describe the recent spatial and temporal variability in surface oceanography of nearshore environments in Pacific Panamá and compare those conditions with the dynamics of contemporary coral-reef communities during and after the 2016 coral-bleaching event. Although both gulfs have warmed significantly over the last 150 yr, the annual thermal maximum in the Gulf of Chiriquí is increasing faster, and ocean temperatures there are becoming more variable than in the recent past. In contrast to historical trends, we found that coral cover, coral survival, and coral growth rates were all significantly higher in the Gulf of Panamá. Corals bleached extensively in the Gulf of Chiriquí following the 2015-2016 El Niño event, whereas upwelling in the Gulf of Panamá moderated the high temperatures caused by El Niño, allowing the corals largely to escape thermal stress. As the climate continues to warm, upwelling zones may offer a temporary and localized refuge from the thermal impacts of climate change, while reef growth in the rest of the eastern tropical Pacific continues to decline.

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Skeleton growth variables of hermatypic corals, such as extension rate, density and calcification rate, are widely used to study coral response to environmental stressors, establish chronological age models and reconstruct the evolution of key climate variables. In this work, we addressed methodological aspects of the measurement of coral growth variables and the implications of their variability. A core of Orbicella faveolata was collected from the Puerto Morelos coral reef, in the Mexican Caribbean, and we measured and analysed 10 parallel transects of a core slab, covering 30 years. Density calibration was performed by measuring a high-quality and well-characterised wedge of Tridacna maxima, and the interval of interest was adjusted to the measured coral optical densities. The measurement uncertainties of extension rate, density and calcification rate were 0.011%, 1.1% and 1.6%, respectively. However, for density and calcification rate, overall variability was 29% and 33%, respectively, of which about half was attributed to intra-band growth variability. The intra-band variability of extension rate was only 0.68%, indicating the suitability of extension rate as a precise environmental proxy. These results likely differ by coral species, environments and experimental conditions, such as the exact location of the core within the colony and the method used to determine density. Uncertainties of coral growth variables should be carefully considered when reconstructing past environmental conditions.

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Historical coral growth assessed by sclerochronology records provides an environmental retrospective and future perspective on the maintenance of coral-reef ecosystems. Three growth parameters, extension rate, skeletal density, and calcification rate were evaluated over the past two decade's interval (1988-2013) in different gender of two massive corals Pavona gigantea and Porites panamensis. The species P. gigantea calcified two-times faster (0.84 ± 0.29 g cm-2 yr-1) than P. panamensis (0.36 ± 0.15 g cm-2 yr-1); and male colonies presents13-58% higher calcification rates than females. Annual growth parameters do not show significant trends over the period 1988-2013, but significant, growth disruption associated with ENSO events. The data presented here suggest that P.gigantea and P.panamensis from the area have developed phenotypic plasticity to a wide range of environmental condition; the life history of both species is reflected in their calcification rates during both optimal and non-optimal conditions over the last two decades. Massive species develop denser structures that provide a permanent habitat to many marine species and contributes to the long-term maintenance of coral reef communities in the eastern tropical Pacific.

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