The purpose of this study is to determine if divers are affecting the reproductive behavior of Halichoeres bivittatus, commonly known as slippery dicks. As an abundant reef fish in the Caribbean, H. bivittatus may be used as a model to study diver impacts on reproductive behavior. If divers are affecting reproductive behavior by delaying the time to reproduction, it could negatively affect the fish’s lifetime reproductive potential and cause decreases in the population at sites with high diver use. I made in situ behavioral observations of H. bivittatus during their daily spawning period between 15:00 and 17:00 h. Spawning rises were enumerated in the presence and absence of a diver to determine if divers affect the number of spawning rises during the observation period. To determine if H. bivittatus become acclimated to the presence of divers, studies at a site with high diver activity were compared to a site with low diver activity. At each site spawning rises were counted in the presence and absence of a diver. An ANOVA indicated that there was no difference in the average number of spawning rises when a diver was present and when a diver was not present. In this study, there was no effect of divers on the reproductive behavior of H. bivittatus
Behavioral and physical differences are sometimes the result of a particular color morphology of a species. Aulostomus maculatus, the west Atlantic Trumpetfish, has three color morphs, and was studied to determine if behavioral or physical differences exist between the three color morphs. This study was conducted at Yellow Sub dive site, located on the leeward side of Bonaire, Dutch Caribbean. Data were collected using SCUBA transects at four depths, and each transect was repeated 6 times. Size (total length, cm), depth (m), environment type (distinguishing corals or objects), substrate type, distance from substrate, body position, and body movement of A. maculatus was recorded for each trumpetfish observed. Significant differences were seen between size and color morph (One-way ANOVA: df = 2, 184, F = 4.30 , p < 0.05), depth and color morph (Kruskal-Wallis: df = 2, Chi-square = 35.11, p < 0.0), and mean density of color morphs at each transect depth (Kruskal-Wallis: df = 2, Chi-square = 11.15, p < 0.01). These results indicate that there are significant differences between the three color morphs of A. maculatus.
Peer-reviewed PHD dissertation, University of California San Diego.
This dissertation is a multi-disciplinary attempt to understand how coral reef resources can be sustainably managed. I begin by examining the peer-reviewed literature on artisanal reef fisheries, identifying gaps in knowledge, and proposing a set of priority areas for future research. Ecological examinations of trap fishing and gill nets follow. Fish trap bycatch can be dramatically reduced by the inclusion of escape gaps that allow juveniles and narrow-bodied species to escape, although catch of ecologically important herbivores remains high. Gill nets capture the few remaining apex
predators present on Caribbean coral reefs, and as such are unsustainable. The second half of the dissertation is a tripartite presentation of the results of interviews with 177 fishers and 211 professional SCUBA divers on Curaçao and Bonaire. First, I consider whether interviewees' baseline conception of a healthy reef ecosystem is actually a degraded state, and they have a "shifting baseline." Then, I evaluate interviewees' discount rates and present bias, and relate those measures to their preferred management approaches. Lastly, I contemplate how to reconcile ecosystem requirements with stakeholder preferences, and use socioeconomic information to develop a sustainable management plan