Graduation Year

2014

Document Type

Thesis

Degree

M.S.

Degree Granting Department

Marine Science

Major Professor

Pamela Hallock Muller

Keywords

Arthropoda, coral, Echinodermata, guilds, Mollusca, survey

Abstract

Benthic mobile invertebrates are important components of coral-reef diversity and community structure, though, in most cases, their ecological contributions are poorly known. Baseline information on their diversity, prevalence, assemblages, and ecological roles is needed to aid in the conservation of coral-reef habitats. The objectives of this study are to 1) describe diversity and assemblages of epibenthic, mobile invertebrates in shallow water coral-reef communities in Florida, 2) evaluate their ecological roles by reviewing published literature on diet, and 3) measure the degree of linear dependence between mobile invertebrates and scleractinian corals. Underwater surveys were conducted in the summer of 2013 at 40 sites distributed along the Florida Reef Tract from Broward County to the Dry Tortugas. The presence/absence of all mobile, epibenthic invertebrate fauna observed were recorded and identified to the lowest level possible. The survey data include 618 records of 116 unique taxa, 83 species, 61 genera, 46 families, 19 orders, seven classes, and four phyla of mobile invertebrates, comprising herbivores, detritivores, carnivores, omnivores, and suspension feeders. These taxa represent 22% of the comparable taxa in a historical dataset that spans 60 years, plus an additional 18 taxa. The survey data also show that the percent composition of major phyla is similar to the historical dataset, despite taxonomic bias evident in the historical dataset. During the survey, novel unique taxa were encountered frequently, but were seldom recurrent, which highlights their cryptic nature. While regional patterns were not identified in the study, assemblages of dominant taxa were characteristic of reef type: echinoderms were the most diverse on patch reefs and southeast Florida reef complexes, mollusks were most diverse on shallow bank reefs, and arthropods were diverse on deep bank reefs, Southeast Florida reef complexes, and shallow bank reefs. Herbivorous mobile invertebrate diversity was negatively correlated with scleractinian coral diversity, underlining competition between corals and macroalgae, and association of herbivores with macroalgae. All of these results suggest that reef types are distinct, but interrelated communities of fauna having specific habitat requirements and important roles. This study also reinforces the challenges in assessing the diverse and often cryptic mobile invertebrate fauna and emphasizes the need for further research and monitoring to detect changes in their communities for the conservation of Florida reef systems.