Allelopathic effects of macroalgae on Pocillopora acuta coral larvae

Jenny Fong; Zi Wei Lim; Andrew G Bauman; Suresh Valiyaveettil; Lawrence M Liao; Zhi Ting Yip; Peter A Todd

doi:10.1016/j.marenvres.2019.06.007

Allelopathic effects of macroalgae on Pocillopora acuta coral larvae

Mar Environ Res. 2019 Oct:151:104745. doi: 10.1016/j.marenvres.2019.06.007. Epub 2019 Jun 11.

Authors

Jenny Fong¹, Zi Wei Lim², Andrew G Bauman², Suresh Valiyaveettil³, Lawrence M Liao⁴, Zhi Ting Yip⁵, Peter A Todd⁶

Affiliations

¹ Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore, 117558, Singapore. Electronic address: jenny.jenny@u.nus.edu.
² Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore, 117558, Singapore.
³ Materials Research Laboratory, Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore.
⁴ Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima, 739-8528, Japan.
⁵ Reef Ecology Laboratory, Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore, 117558, Singapore.
⁶ Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore, 117558, Singapore. Electronic address: dbspat@nus.edu.sg.

PMID: 31229278
DOI: 10.1016/j.marenvres.2019.06.007

Abstract

Allelopathy has been proposed as a key mechanism mediating coral-algal interactions; however, few studies have tested macroalgal allelochemicals on coral larvae. In this study, we examined the effects of crude extracts from four macroalgal species on Pocillopora acuta larvae under different exposure conditions. Larval mortality increased considerably with increasing concentrations of Bryopsis sp., Endosiphonia horrida, and Lobophora sp. extracts. Increasing E. horrida and Lobophora sp. extract concentrations also substantially decreased larval settlement. No detectable effects on larvae were observed in Hypnea pannosa extracts. Further, while larval mortality increased with exposure duration to Lobophora sp. extracts, larval settlement was enhanced at 12 h exposure, but reduced at shorter and longer durations. Our results emphasize that macroalgal chemical effects are highly dependent on macroalgal species and exposure conditions. On reefs dominated by allelopathic macroalgae, the survivorship and settlement of coral larvae are potentially constrained, thereby limiting the recovery of degraded reefs.

Keywords: Allelopathy; Larvae; Larval bioassay; Macroalgae; Pocillopora; Settlement.

MeSH terms

Allelopathy*
Animals
Anthozoa* / genetics
Coral Reefs
Larva
Seaweed*