Direct seeding of mass-cultured coral larvae is not an effective option for reef rehabilitation

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 525:105-116 (2015) - DOI: https://doi.org/10.3354/meps11171 Direct seeding of mass-cultured coral larvae is not an effective option for reef rehabilitation Alasdair J. Edwards1,*, James R. Guest1,5, Andrew J. Heyward2, Ronald D. Villanueva3, Ma. Vanessa Baria3, Iris S. F. Bollozos3, Yimnang Golbuu4 1School of Biology, Ridley Building, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom 2Australian Institute of Marine Science, University of Western Australia Oceans Institute (M096), Crawley 6009, Western Australia, Australia 3The Marine Science Institute, College of Science, University of the Philippines Diliman, 1101 Quezon City, Philippines 4Palau International Coral Reef Center, PO Box 7086, Koror, Palau 96940 5Present address: Advanced Environmental Biotechnology Centre, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, #06-08, Singapore 637141 *Corresponding author: alasdair.edwards@newcastle.ac.uk ABSTRACT: Large-scale rearing of coral larvae during mass spawning events and subsequent direct introduction of competent larvae onto denuded reefs (‘larval seeding’) has been proposed as a low-tech and affordable way of enhancing coral settlement and hence recovery of degraded reefs. While some studies have shown positive short-term effects on settlement, to date, none have examined the long-term effects of larval seeding for a broadcast-spawning coral. Here, we test whether larval seeding significantly increases coral recruitment rates both in the short (5 wk) and longer (~6 mo to 1 yr) term. Larvae of Acropora digitifera were reared ex situ, and ~1 million larvae were introduced to 7 artificial reefs (ARs) while 7 others were left unseeded. Settlement tiles deployed on both seeded and control ARs were retrieved for examination 5 and 30 wk after seeding. In addition, the presence of visible coral recruits on the AR surfaces was monitored before and for ~13 mo post-seeding. Density of acroporid spat was significantly higher on seeded tiles than on controls 5 wk after seeding, but this effect had vanished by 30 wk. Comparison of the densities of new visible Acropora recruits between seeded and control ARs showed no significant difference ~13 mo after seeding. Larval seeding therefore had no long-term effect due to high post-settlement mortality (which appeared to be density-related). Results suggest that reef-rehabilitation methods that aim to harness coral sexual reproduction might better focus on rearing juveniles through early post-settlement mortality bottlenecks. KEY WORDS: Larval seeding · Coral reef rehabilitation · Larval rearing · Acropora digitifera · Mass spawning · Density-dependent mortality · Palau Full text in pdf format PreviousNextCite this article as: Edwards AJ, Guest JR, Heyward AJ, Villanueva RD, Baria MV, Bollozos ISF, Golbuu Y (2015) Direct seeding of mass-cultured coral larvae is not an effective option for reef rehabilitation. Mar Ecol Prog Ser 525:105-116. https://doi.org/10.3354/meps11171 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 525. Online publication date: April 09, 2015 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2015 Inter-Research.