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National Committee on Marine Sciences (NCMS)

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Author: search.filters.author.Ligson, Charlon A.Geographic name: search.filters.geographicname.Philippines

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    Survival and sexual maturity of sexually propagated Acropora verweyi corals 4 years after outplantation
    Ligson, Charlon A.; Cabaitan, Patrick C. (Wiley, 2021-04-19)
    Most coral reef restoration efforts are carried out over 1–2 years, and few have assessed long-term (over 3 years) outcomes. Although studies of outplantation of sexually propagated corals have reported promising initial results, few studies have followed outplanted corals to maturity. Here, we monitored sexually propagated Acropora verweyi corals for 4 years post-outplantation to determine their survival and sexual maturity. These corals were outplanted when 4 months old in two size classes (small = 0.3–0.5 cm; large = 1.0–1.5 cm) at two sites in the northwestern Philippines. Four years after outplantation, the 240 colonies of A. verweyi exhibited 17.9% survival, with mean diameters ranging from 7.48–26.8 cm. Most of the surviving outplants were gravid (81.4% of the 43 colonies) with mean diameters of at least 11.8 cm. Higher survivorship was detected in the initial large size class outplants than in the small ones at the natal site, but not at the other site. However, 4 years after outplantation, there was no significant difference in terms of geometric mean diameter between the initial size classes or between the sites. Results show that 4-month-old outplants of sexually propagated corals can survive until sexual maturity and are already capable of contributing gametes for the potential recovery of degraded coral communities at age 4 years.
    The authors are grateful to Ronald de Guzman, Francis Kenith Adolfo,and Renato Adolfo for the field and hatchery assistance.This study was supported by a grant from the Philippine Council for Agriculture, Aquatic, and Natural Resources Research and Development of the Department of Science and Technology to PCC. The authors are also grateful to Prof. Peter Harrison for providing CAL a research assistantship opportunity and for additional logistical support through an Philippine Council for Agriculture, Aquatic, and Natural Resources Research and Development.
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    Fish farm effluents alter reef benthic assemblages and reduce coral settlement
    Quimpo, Timothy Joseph R.; Ligson, Charlon A.; Manogan, Dana P.; Requilme, Jeremiah Noelle; Albelda, Ritzelle L.; Conaco, Cecilia; Cabaitan, Patrick C. (Elsevier Ltd., 2020)
    Fish farming in coastal areas is a rapidly growing industry. However, unregulated fish farming practices that release massive amounts of unconsumed feed and fecal material into the water column, can result in a nutrient enriched environment that extends to nearby reef systems. To understand the impact of fish farm effluent on coral settlement, we tested the settlement rate of Pocillopora acuta larvae on artificial substrates conditioned for 12 weeks at three sites with increasing distance (2–10 km) from fish farms in Bolinao, Philippines. Sites far from the fish farms had higher biofilm and crustose coralline algae cover. In contrast, the site closest to the fish farms, where nutrient levels were higher, had greater sediment and turf algae cover. Tiles conditioned at the farther sites promoted higher (6–8%) larval settlement whereas tiles from the nearer site had lower settlement (3%). These findings show that fish farm effluents can indirectly affect coral settlement on adjacent reefs by promoting growth of other biota that may inhibit larval settlement and by reducing the availability of suitable substrate.