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Corals display different growth forms as an adaptive response to both local and global environmental conditions. Despite the importance of morphologic variability on corals, growth and calcification rates of different coral morphotypes have been poorly recorded in the Eastern Pacific. The purpose of this study was to compare annual extension rate (cm yr −1 ), skeletal density (g cm −3 ), calcification rate (g cm −2 yr −1 ), and tissue thickness (mm) of males and females colonies in three different morphotypes of the common reef-building coral Porites lobata; columnar, massive, and free-living (corallith) forms. The results show significant differences in all four-growth parameters between morphotypes over a 6-year interval, and also differences between males and females in most morphotypes. Massive colonies presented 15-33% faster annual rates compared with columnar and free-living. Male colonies showed 30-40% faster annual rates than females for both columnar and corallith morphologies. These data exhibit the extensive plasticity of this species and highlight the fact that each morphotype × gender group produced a different physiological response to environmental conditions. Therefore, these information reveal that P. lobata from the Eastern Tropical Pacific develops different morphologies to allow it to maintain coral species population, characteristics that enhance the species possibility to further its distribution across the reef-framework.

Pocilloporids are one of the major reef-building corals in the eastern tropical Pacific (ETP) and also the most affected by thermal stress events, mainly those associated with El Niño/Southern Oscillation (ENSO) periods. To date, coral growth parameters have been poorly reported in Pocillopora species in the northeastern region of the tropical Pacific. Monthly and annual growth rates of the three most abundant morphospecies (P. cf. verrucosa, P. cf. capitata, and P. cf. damicornis) were evaluated during two annual periods at a site on the Pacific coast of Mexico. The first annual period, 2010–2011 was considered a strong ENSO/La Niña period with cool sea surface temperatures, then followed by a non-ENSO period in 2012–2013. The linear extension rate, skeletal density, and calcification rate averaged (±SD) were 2.31 ± 0.11 cm yr−1, 1.65 ± 0.18 g cm−3, 5.03 ± 0.84 g cm−2 yr-1 respectively, during the strong ENSO event. In contrast, the respective non-ENSO values were 3.50 ± 0.64 cm yr−1, 1.70 ± 0.18 g cm−3, and 6.02 ± 1.36 g cm−2 yr−1. This corresponds to 52% and 20% faster linear extension and calcification rates, respectively, during non-ENSO period. The evidence suggests that Pocillopora branching species responded positively with faster growth rates following thermal anomalies, which allow them to maintain coral communities in the region.

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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.

El desarrollo y el mantenimiento de los arrecifes coralinos depende del balance entre la producción (acreción) y la remoción (erosión) del CaCO3 generado principalmente por corales hermatípicos. El material calcáreo puede ser removido del esqueleto de coral por agentes físicos, químicos o biológicos, y este último es el de mayor influencia. Pese a su importancia, pocos estudios han estimado la tasa de bioerosión en comunidades coralinas de la costa mexicana del Pacífico. En este estudio se determinó el volumen y el porcentaje de CaCO3 removido vía erosión biológica en los principales corales masivos, Pavona gigantea, Porites lobata y Porites panamensis, distribuidos en el Parque Nacional Islas Marietas y el Parque Nacional Isla Isabel (México). Además, se evaluó el efecto de factores intrínsecos (morfología, sexo y edad de las colonias) y extrínsecos (localidad y profundidad) en la bioerosión. Se utilizó la técnica de peso boyante para calcular parámetros de remoción interna y densidad de CaCO3. A nivel de especie, P. gigantea presentó valores de volumen de bioerosión de 71.31 ± 32.35 cm3 (27.28 ± 18.05% de bioerosión interna); Po. lobata, 26.60 ± 4.87 cm3 (16.87 ± 16.31%); y Po. panamensis, 29.6 ± 14.61 cm3 (31.127 ± 29.43%). A nivel de género, Pavona presentó los valores más altos en bioerosión y densidad del esqueleto (1.61 g·cm–3). Con relación a la morfología, la bioerosión fue mayor en colonias masivas, pero considerando la edad, fue superior en colonias más longevas (10–26 años). A nivel de localidad, en el Parque Nacional Islas Marietas se presentaron los valores más altos de volumen y porcentaje de bioerosión. La evidencia sugiere que los arrecifes de coral de la costa central mexicana del Pacífico están experimentando una alta tasa de erosión no conspicua causada por bioerosionadores endolíticos y varía en función de factores intrínsecos y extrínsecos. Si este efecto continúa incrementando, podría poner en riesgo el mantenimiento a largo plazo de las comunidades coralinas, lo que modificaría el balance de los flujos de carbonato y la funcionalidad del ecosistema arrecifal.