First year research by Melissa Roth

 
Objective
The goal of this study was to investigate how size of reef fish effects herbivory of macroalgal communities on coral reefs. Herbivory will be examined in the following components: grazing intensity, food selectivity, and incorporation of food sources into fish tissue. This project examines different size classes of parrotfish within a species, as well as three parrotfish species of different sizes. The three species of parrotfish included in this study are a small sized parrotfish Scarus iserti, a medium sized parrotfish Sparisoma viride, and a large parrotfish Scarus coelestinus. Ecological data, behavioral observations, isotopic analyses will be used to answer the research question.

Conservation Implications
The type and intensity of herbivores will have consequences on the macroalgal communities on coral reefs. Understanding herbivory is essential for effective conservation because it a principal dynamic structuring reefs. Scientists and managers will need to anticipate what the consequences for macroalgal communities will be when the size structure of herbivorous fish is changed from the removal of large herbivores. With many reefs already shifted to a macroalgal dominated state and managers creating Marine Protected Areas, it will be important to quantify the level of herbivory that may be required to control and reduce macroalgal overgrowth. Thus, implications of this research will be relevant for managers protecting coral reefs. Unlike other herbivores such as urchins, grazing fish populations can be managed by changing the fishing pressure.

Results are summarized in the this poster (download pdf).

For methods and a full discussion of results please contact the author:
mroth@ucsd.edu

This material is based upon work supported by the National Science Foundation under Grant No. 0333444.
Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.