Due to the worldwide degradation of coral reefs, the active restoration of these ecosystems has received considerable attention in recent decades. This study investigated (1) the feasibility of using coral nurseries for restoration projects, (2) the minimum size required for a Pocillopora damicornis (Pocilloporidae) coral fragment to survive and grow in a nursery, and (3) the optimal transplant size of a fragment when transplanted to a degraded reef at Gorgona Island (Colombian Pacific). For this investigation, 230 fragments were transplanted directly to El Remanso reef, and another 150 fragments were maintained in in situ nurseries. Every 2 months, the length, weight, and survival of the fragments were recorded. After growing for 134 days in the nurseries, the 52 surviving fragments were transplanted to El Remanso reef, and after 5 months, the same variables were measured. Among the nursery-reared fragments, the largest (4 to <8 cm) had the highest survival and growth rates, whereas among the directly transplanted fragments, the smallest fragments (<2 cm) had the highest survival and growth rates. However, the nursery-reared fragments acquired greater structural complexity (arborescent morphology), and they were all alive 156 days after transplantation and presented a maximum linear growth rate of over 2 cm, which was higher than that of the directly transplanted fragments. Apparently, the arborescent morphology acquired during the nursery period provides advantages to the colonies that favor greater success when transplanted. Therefore, nursery-reared fragments of P. damicornis between 2 and 4 cm are the most appropriate for use in restoration projects.

Se compararon los ensamblajes de anuros de tres hábitats (bosque, lago y cantera) con diferente grado de perturbación antrópica presentes en un fragmento de bosque seco en la hacienda La Española, corregimiento de Guarinocito, Caldas. Se realizaron muestreos de recorridos extensivos usando el método de registro por relevamiento por encuentros visuales (REV), a partir de los cuales se registró la abundancia y uso del microhábitat para cada una de las especies dentro de los diferentes hábitats, y se realizó el registro de variables ambientales descriptoras del sitio de muestreo, tales como temperatura, humedad relativa y perímetro de espejos de agua. Se encontraron 13 especies de anuros, entre las cuales Engystomops pustulosus registró la mayor abundancia relativa, con una tasa de captura de 5,16 individuos por hora. Se registraron diferencias significativas en la diversidad entre los hábitats de estudio, siendo menor en el bosque, en donde hubo menor riqueza, pero mayor dominancia. La tasa de recambio de especies entre hábitats fue del 71%, exhibiendo Lago y Cantera la mayor similitud en composición de la anurofauna. El uso de sustrato por parte de cada especie en los diferentes hábitats registró diferencias significativas (X², p<0,05) y solo dos especies (Leptodactylus fragilis y L. colombiensis) presentaron alta variabilidad en los sustratos usados.

Mass bleaching and subsequent mortality of reef corals by heat stress has increased globally since the late 20th century, due to global warming. Some experimental studies have reported that corals may increase heat tolerance for short periods, but only a few such studies have monitored naturally-growing colonies. Therefore, we monitored the survival, growth, and bleaching status of Acropora corals in fixed plots by distinguishing individual colonies on a heat-sensitive reef flat in Okinawa, Japan. The level of heat stress, assessed by the modified version of degree heating week duration in July and August, when the seawater temperature was the highest, was minimally but significantly higher in 2017 than in 2016; however, the same colonies exhibited less bleaching and mortality in 2017 than in 2016. Another study conducted at the same site showed that the dominant unicellular endosymbiotic algal species did not change before and after the 2016 bleaching, indicating that shifting and switching of the Symbiodiniaceae community did not contribute to improved heat tolerance. Colonies that suffered from partial mortality in 2016 were completely bleached at higher rates in 2017 than those without partial mortality in 2016. The present results suggest that either genetic or epigenetic changes in coral hosts and/or algal symbionts, or the shifting or switching of microbes other than endosymbionts, may have improved coral holobiont heat tolerance.

The symbiotic relationship between scleractinian corals and dinoflagellates is a cornerstone of coral reef ecosystems. Various mechanisms underlying the adaptability of corals to environmental changes have been studied, but the effects of epigenetic mechanisms (i.e. DNA methylation, DNAm) on heat stress and the symbiotic conditions of corals remain unclear. Moreover, the DNAm patterns relevant to the primary polyp life stage of corals are not known. Hence, we conducted an aquarium factorial experiment to evaluate the effects of symbiotic conditions and temperatures on global DNAm rates in primary Acropora digitifera polyps. The tested conditions included symbiotic (infected with Symbiodinium ITS2 type A3) and aposymbiotic (without Symbiodinium) groups, at either heated (32°C) or ambient (27°C) temperatures. The results indicated that the presence of Symbiodinium within primary A. digitifera polyps significantly decreased basal DNAm rates of the coral holobiont. In addition, the presence of Symbiodinium in the early primary polyp stage increased DNAm in the coral holobiont when exposed to heat stress. These results suggest that the symbiotic relationship between host corals and Symbiodinium is one of the major factors related to global DNAm rate changes in primary A. digitifera polyps.