Temporal variation in macroalgal removal: insights from an impacted equatorial coral reef system

Authors

Jovena C. L. Seah, National University of Singapore
Andrew G. Bauman, National University of SingaporeFollow
Peter A. Todd, National University of Singapore

Document Type

Article

Publication Date

1-4-2021

Publication Title

Marine Biology

ISSN

0025-3162

Volume

168

Issue/No.

2

Abstract

Macroalgal removal is a critical ecosystem function yet few studies have considered its temporal variability, especially on impacted reefs with limited herbivorous fish biodiversity. To address this, we quantified macroalgal removal and mass-standardised bite rates of herbivorous fishes monthly from July 2016 to June 2017 using a series of transplanted Sargassum ilicifolium assays and underwater video cameras on three degraded coral reefs in Singapore: Pulau Satumu, Kusu Island, and Terumbu Pempang Tengah. Our results revealed a distinct temporal pattern in macroalgal herbivory (proportion of biomass removed and mass-standardised bite rates) rates across all sites, increasing from July and decreasing from January, with the highest rates recorded in December (28.10 ± 3.05 g 3.5 h⁻¹; 208.24 ± 29.99 mass-standardised bites 3.5 ^h−1) and the lowest in May (0.86 ± 0.17 g 3.5 ^h−1; 9.55 ± 3.19 mass-standardised bites 3.5 ^h−1). These coincided with the S. ilicifolium growth cycle, confirming previous evidence that herbivory rates are closely linked to macroalgal condition. Video analyses revealed nine species feeding over a year (31,839 bites; 8702.89 mass-standardised bites), with Siganus virgatus responsible for ∼ 80% of the total mass-standardised bites. Siganus virgatus took the largest proportion of bites monthly, except between April and June, when Scarus rivulatus was dominant, suggesting temporal constraints in functional roles.

Comments

Electronic supplementary material

Supplementary file1 (PDF 158 KB)

Additional Comments

This research is supported by the AXA Fellowship (154-000-649-507), Wildlife Reserves Singapore Conservation Fund, and the National Research Foundation, Prime Minister’s Office, Singapore under its Marine Science Research and Development Program (Award Nos. MSRDP-P03).

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

NSUWorks Citation

Jovena C. L. Seah, Andrew G. Bauman, and Peter A. Todd. 2021. Temporal variation in macroalgal removal: insights from an impacted equatorial coral reef system .Marine Biology , (2) . https://nsuworks.nova.edu/occ_facarticles/1256.

ORCID ID

0000-0001-9260-2153

DOI

10.1007/s00227-020-03806-7