Natural disturbances and human activities can alter the benthic composition of coral reefs and other marine ecosystems. Reef fishes that associate with particular structures on the sea floor, such as coral heads, may be vulnerable to perturbations of those habitats. The spread of a newly discovered crustose alga (Ramicrusta sp.) on coral reefs in Lac Bay, Bonaire, has shifted the dominant coral benthos to a crust-covered seascape, posing a potential threat to habitat availability for the local reef-fish community. This study investigated the response of fish assemblages to Ramicrusta overgrowth of the hydrozoan fire coral Millepora complanata. I conducted visual surveys by snorkel throughout the back reef of the bay which assessed fish abundance and family diversity with respect to a gradient of Ramicrusta overgrowth of M. complanata. Of 170 observed heads of M. complanata, 88% were covered with varying degrees of Ramicrusta. Fish abundance differed significantly between high (26-100%) and low (0-25%) levels of overgrowth, yet this trend was likely influenced by larger heads of M. complanata having higher levels of Ramicrusta coverage. Differences in fish family diversity along a gradient of Ramicrusta coverage of M. complanata were not statistically significant. Field observations suggest the presence of Ramicrusta does not have a substantial impact on the structural complexity of M. complanata. Little change in habitat complexity suggests that fishes are capable of using M. complanata as habitat regardless of the extent of Ramicrusta overgrowth.  

Authors: 
AnnaRose Adams
Short Description: 
This study investigated the response of fish assemblages to Ramicrusta overgrowth of the hydrozoan fire coral Millepora complanata.
Product Number: 
ORESU-Y-10-015
Entry Date: 
Thursday, July 11, 2013
Price: 
NA
Length: 
34 pp.
Size and Format: 
8 1/2 x 11, online
Department/University: 
University Honors College, Oregon State University
Degree: 
Honors Baccalaureate of Science in BioResource Research (Honor Associate), Option Sustainable Ecosystems
Year of Publication: 
2010
How to Order: 

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