Differential Response of the Microbiome of Pocillopora acuta to Reciprocal Transplantation Within Singapore

Lindsey K Deignan,Diane Mcdougald

doi:10.1007/s00248-021-01793-w

Abstract

As corals continue to decline globally, particularly due to climate change, it is vital to understand the extent to which their microbiome may confer an adaptive resilience against environmental stress. Corals that survive on the urban reefs of Singapore are ideal candidates to study the association of scleractinians with their microbiome, which in turn can inform reef conservation and management. In this study, we monitored differences in the microbiome of Pocillopora acuta colonies reciprocally transplanted between two reefs, Raffles and Kusu, within the Port of Singapore, where corals face intense anthropogenic impacts. Pocillopora acuta had previously been shown to host distinct microbial communities between these two reefs. Amplicon sequencing (16S rRNA) was used to assess the coral microbiomes at 1, 2, 4, and 10 days post-transplantation. Coral microbiomes responded rapidly to transplantation, becoming similar to those of the local corals at the destination reef within one day at Raffles and within two days at Kusu. Elevated nitrate concentrations were detected at Raffles for the duration of the study, potentially influencing the microbiome’s response to transplantation. The persistence of corals within the port of Singapore highlights the ability of corals to adapt to stressful environments. Further, coral resilience appears to coincide with a dynamic microbiome which can undergo shifts in composition without succumbing to dysbiosis.

Highlights

Scleractinian corals are the building blocks of ecologically and economically valuable reef ecosystems, yet corals are experiencing ongoing global declines [1, 2]
The coral Porites lobata maintained a stable microbiome during a bleaching event, which supported some protective functions in the host despite the adverse physiological effects of bleaching [20]
This study focuses on Pocillopora acuta, a resilient coral species found in relatively high abundance on reefs throughout Singapore’s Southern Islands [25, 29]

Summary

Introduction

Scleractinian corals are the building blocks of ecologically and economically valuable reef ecosystems, yet corals are experiencing ongoing global declines [1, 2]. Corals host a diverse microbial community, or microbiome, that plays essential roles in healthy coral functions, including nutrient cycling and immune responses [3, 6]. While coral microbiomes are generally comprised of species-specific communities [11, 12], environmental perturbations like nutrient or temperature fluxes can induce compositional shifts that vary both spatially [13] and temporally [14,15,16,17]. It has been proposed that coral species that maintain stable microbiomes may be more tolerant to environmental stressors [18, 19]. The coral Porites lobata maintained a stable microbiome during a bleaching event, which supported some protective functions in the host despite the adverse physiological effects of bleaching [20]. Coral microbiome beta diversity is reported to increase with cumulative environmental stressors [16, 17,

Methods

Results

Conclusion