Grazing pressure on coral reefs decreases across a wide depth gradient in the Gulf of Aqaba, Red Sea

Brokovich, Eran, Ayalon, Inbal, Einbinder, Shai, Segev, Nitzan, Shaked, Yonathan, Genin, Amatzia, Kark, Salit and Kiflawi, Moshe (2010) Grazing pressure on coral reefs decreases across a wide depth gradient in the Gulf of Aqaba, Red Sea. Marine Ecology Progress Series, 399 69-80. doi:10.3354/meps08354


Author Brokovich, Eran
Ayalon, Inbal
Einbinder, Shai
Segev, Nitzan
Shaked, Yonathan
Genin, Amatzia
Kark, Salit
Kiflawi, Moshe
Title Grazing pressure on coral reefs decreases across a wide depth gradient in the Gulf of Aqaba, Red Sea
Journal name Marine Ecology Progress Series   Check publisher's open access policy
ISSN 0171-8630
1616-1599
Publication date 2010-01
Year available 2010
Sub-type Article (original research)
DOI 10.3354/meps08354
Open Access Status DOI
Volume 399
Start page 69
End page 80
Total pages 12
Place of publication Oldendorf, Germany
Publisher Inter-Research
Collection year 2010
Language eng
Formatted abstract
 Algae are an essential component of healthy coral reefs and serve as the base of the food chain and as a living habitat for numerous organisms. Herbivorous fish play an important role in coral reef ecology by mediating competition between fast-growing algae and relatively slow-growing corals. However, because of diving-related difficulties, the importance of herbivory in deep mesophotic coral reefs (30 to 150 m) remains largely unknown. We examined the relationship between herbivores and algae along a depth gradient down to 65 m, and evaluated grazing pressure along the depth gradient. We visually assessed the abundance of herbivorous fish along the depth gradient and estimated fish biomass. We measured in situ turf algae growth rates and performed experimental assessments of grazing pressure using settlement plates and bioassays. We discovered that, while both algal growth and fish density decrease with depth, the decrease in grazing pressure is steeper, with a consumption of <20% of turf-algae production at 65 m versus 40 to 60% at depths of 5 to 20 m. Concomitantly, a decrease in fish biomass and density along the depth gradient reduced potential grazing pressure on macroalgae. Our findings suggest a less important role for herbivorous fish in maintaining algal-free substrate for coral recruitment and growth in deep zones compared with the shallow reef.
Keyword Depth gradient
Deep reefs
Gulf of Aqaba
Herbivore fish
Benthic algae
Marine Herbivorous Fishes
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Biological Sciences Publications
 
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