Survival and sexual maturity of sexually propagated Acropora verweyi corals 4 years after outplantation

Abstract

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.

Synchronous spawning of nursery-raised elkhorn coral (Acropora palmata) outplanted to reefs in the Florida Keys (United States)

“…In 2022, we observed spawning activity among A. palmata colonies outplanted in March 2018, indicating that nursery-raised fragments outplanted to Florida reefs can become reproductively mature in as little as four years and four months (52 months) after outplanting. This is consistent with the observation of A. palmata outplants spawning ~60 months post outplanting in Belize (Carne et al, 2016) and four-year-old (48 months) sexual recruits of A. palmata being reproductively mature in Curacao (Chamberland et al, 2016) and other species of acroporids spawning at 4-5 years old (Calle-Triviño et al, 2018;Ligson and Cabaitan, 2021).…”

Ontogenetic shifts in Symbiodiniaceae assemblages within cultured Acropora humilis across hatchery rearing and post-transplantation phases

“…Corals hosting Cladocopium have often shown faster growth, potentially indicating a greater transfer of photosynthetically fixed carbon to their host (Cantin et al, 2009;Cunning et al, 2015). Coral sexual maturity is size-dependent; some faster-growing staghorn corals can reach maturity at around 2-4 years of age (Ligson & Cabaitan, 2021;Suzuki, 2021). Therefore, the time it takes for corals harboring Cladocopium to reach full mature size and produce offspring may be shorter, allowing them to increase their population faster than some massive corals (Van Oppen & Medina, 2020).…”