Parrotfish Grazing On Coral Reefs

Author : Jihane Benbahtane
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (126 download)

DOWNLOAD NOW!

Download or read book Parrotfish Distribution and Feeding Behaviour in a Fringing Reef of Barbados written by Jihane Benbahtane and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Coral reefs are among the most ecologically diverse and productive ecosystems in the world, but they are unfortunately subjected to a vast range of environmental disturbances and are declining globally. A better understanding of the ecological mechanisms that promote reef health and recovery is thus of prime importance. Reef ecologists are particularly interested in parrotfishes as a herbivorous group. Parrotfish species have been identified as keystone herbivores whose grazing action effectively removes macroalgae that compete for space with coral recruits, and can thus help maintain benthic equilibrium and prevent coral communities from shifting to macroalgae dominated states. Decades of research have demonstrated that parrotfish species are likely to have context-dependent grazing properties that change as a function of reef ecological dynamics. In this thesis, I examine the processes driving the spatial distribution of species in a parrotfish community, and investigate the factors influencing their feeding behaviour. In Chapter 1, I review the literature on parrotfishes to provide an overview of the different mechanisms underlying parrotfish distribution and feeding behaviour identified by previous research. In Chapter 2, I present the results of an empirical study I conducted on a parrotfish community across a fringing reef in Barbados. I first determined that there is little diversity in the benthic composition and that the reef is dominated by filamentous algae. I tested the hypothesis that species identity, ontogeny, and size influence feeding behaviour in five co-existing parrotfish species. I found that ontogeny, size, and species identity significantly influence feeding rate, but conclude that the respective effects of ontogeny and size cannot be teased apart. I also found that there was overall not much variation in food electivity between species and through ontogeny, as turf algae dominated the diet of all species and phases, most likely due to the lack of diversity in the benthos. I also tested the hypothesis that the spatial pattern of species abundance was related to the abiotic and biotic properties of the reef, and that this relation was modulated by feeding mode and body size. I found significant associations between species abundance and the reef’s environmental structure, but that associations were only marginally mediated by feeding mode and body size. Additionally, I show that the choice of survey method has an impact on species abundance estimates for parrotfish species and discuss the importance of using multiple survey methods to account for method-specific biases that can alter results of studies on parrotfish ecological dynamics. In coral reef ecosystems, understanding the mechanisms of parrotfish herbivory is paramount since they can play a significant role in maintaining reef health. The research I present in this thesis highlights the importance of studying how these mechanisms can be dependent on the ecological context of the study system"--