Document Type

Open Access Thesis

Embargo Period

4-5-2016

Degree Program

Marine Sciences and Technology

Degree Type

Master of Science (M.S.)

Year Degree Awarded

2016

Month Degree Awarded

May

Abstract

Marine protected areas (MPAs) are increasing in popularity as a tool to manage fish stocks through conservation of entire habitats and fish assemblages. Quantifying the habitat use, site fidelity, and movement patterns of marine species is vital to this method of marine spatial planning. The success of these protected areas requires that sufficient habitat is guarded against fishing pressure. For large animals, which often have correspondingly large home range areas, protecting an entire home range can be logistically challenging. For MPAs to successfully protect large top predator species, it is important to understand what areas of a home range are especially important, such as breeding and feeding grounds. New technologies, such as acoustic telemetry, have made it possible to track marine animal movements at finer spatial and temporal scales than previously possible, better illuminating these spatial use patterns. This study focused on the movement patterns of great barracuda (n=35), an ecologically important top predator, around Buck Island Reef National Monument, a no-take MPA in St. Croix, U.S.V.I. managed by the National Park Service. As developing standardized methods for acoustic telemetry is still a work in progress, the first half of this study focuses on determining appropriate tools for generating home range size estimates for great barracuda and analyzing ecological parameters driving these results. The second half of this study focused on the use of network analysis to look at spatial divisions within individual home ranges and to compare individual to population level spatial patterns, as well as to generate a relative estimate of population density within the park. Barracuda within the park demonstrated high site fidelity to individual territories, but at the population level they consistently used all habitats within the array. Core use areas within home ranges were evenly distributed throughout all habitats monitored by the acoustic array, although movement corridors were detected along high rugosity reef structures. Greater population densities within the park indicate that density dependent behaviors may be influencing habitat use within the park, and suggest that barracuda are contributing high levels of top down pressure through predation within the park boundaries.

First Advisor

Adrian Jordaan

Second Advisor

Andy Danylchuk

Third Advisor

John Finn

Fourth Advisor

Greg Skomal

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