Biologically mediated sediment fluxes on coral reefs: sediment removal and off-reef transportation by the surgeonfish 'Ctenochaetus striatus'

Title
Biologically mediated sediment fluxes on coral reefs: sediment removal and off-reef transportation by the surgeonfish 'Ctenochaetus striatus'
Publication Date
2010
Author(s)
Goatley, Christopher
( author )
OrcID: https://orcid.org/0000-0002-2930-5591
Email: cgoatley@une.edu.au
UNE Id une-id:cgoatley
Bellwood, David R
Type of document
Journal Article
Language
en
Entity Type
Publication
Publisher
Inter-Research
Place of publication
Germany
DOI
10.3354/meps08761
UNE publication id
une:21071
Abstract
Off-reef sediment transport by the surgeonfish 'Ctenochaetus striatus' (Acanthuridae) was quantified on the reef crest at Lizard Island, Great Barrier Reef. Three independent methods were implemented to estimate sediment ingestion rates. These considered (1) the bite rate and bite volume, (2) the defecation rate and faecal pellet size, and (3) the average gut contents and throughput rate. The 3 methods provided a broad range of estimates of sediment ingestion from 8.8 ± 2.4, to 66.1 ± 14.4 g fish-1 d-1 (mean ± SE). Nevertheless, these estimates were comparable to rates of sediment ingestion by parrotfishes (Labridae), the other major sediment-moving group on reefs. Overall, 36.5% of all sediment ingested was transported from the upper reef crest into deeper water, equating to a removal rate of 28.6 ± 6.2 kg 100 m-2 yr-1 at the study site. By brushing the reef, 'C. striatus' reduces the sediment loading in the epilithic algal matrix (EAM) while causing little damage to the algal turf. Reducing sediments in EAMs provides favourable settlement surfaces for benthic organisms and increases the palatability of the EAM to herbivorous reef fishes, thus supporting reef resilience. The ecological importance of 'C. striatus', which is abundant on reefs throughout the IndoPacific, appears to have been underestimated, particularly when considering reef sediment dynamics.
Link
Citation
Marine Ecology Progress Series, v.415, p. 237-245
ISSN
1616-1599
0171-8630
Start page
237
End page
245

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