Publication Date

2016-08-03

Availability

Open access

Embargo Period

2016-08-03

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PHD)

Department

Marine Biology and Fisheries (Marine)

Date of Defense

2016-04-01

First Committee Member

David J. Die

Second Committee Member

Andrew Bakun

Third Committee Member

Claire B. Paris-Limouzy

Fourth Committee Member

Kathleen S. Sealey

Fifth Committee Member

Brice Semmens

Abstract

The global nature of travel and trade has increased the potential for the spread of invasive species around the world. These invasive alien species (IAS) have the potential to negatively influence the ecosystems they invade by preying upon, infecting or out-competing native species or altering their new habitat. The invasion of two Indo-Pacific lionfishes, Pterois volitans and Pterois miles, is having far reaching impacts on reef fish biodiversity and abundance throughout the Tropical Western Atlantic Ocean. The body of lionfish research from their native range is composed of studies related to their biology or behaviors in aquarium settings. These deficiencies have left researchers with knowledge gaps related to why lionfish spread so rapidly and the best methods to control lionfish abundance in the diverse habitats they occupy. Analysis of juvenile otolith birthdates verified that lionfish successfully spawn throughout the calendar year. This information was coupled with known early life history traits of lionfish to simulate dispersal of “lionfish” particles in the Caribbean. This dispersal identified Florida, the Bahamas and Cuba as major sinks for lionfish larvae throughout the region, and Jamaica as an important link between the Greater Antilles and southern portions of the Caribbean. Additionally, lionfish reproductive strategy facilitated their spread across a known geographic barrier between Florida and the Caribbean that creates a genetic break between native reef fishes. Highly connected dispersal pathways, continuous spawning of lionfish, and the lack of natural predators help to make lionfish more successful in the invaded range, and prompt the development of management plans to counteract this growth. Lionfish are present in a host of diverse habitats, but monitoring and culling is restricted to shallow, diveable waters. A two-year observer study in the deeper water spiny lobster trap fishery (>20 m) was used to investigate the distribution of lionfish in an understudied environment. Lionfish have become a major component of the fishery’s bycatch, and the trap fishery provides an additional mechanism for lionfish removals. This method can eliminate a larger number of individuals than the traditional methods used in shallower water culling derbies. The lack of lionfish caught in the shallower fishing areas precipitated a series of tank experiments to investigate the preference for benthic structures found in the different depth regimes within the fishery. Lionfish spent more time associating with coralline habitat structures than any other, but they were displaced from this habitat in the presence of lobster. The exclusionary behaviors of lobster indicate their potential to alter lionfish habitat choices. These insights provide marine managers with information to understand invasive species ecological dynamics, to better manage for future invasions, and to mitigate the impacts of lionfishes.

Keywords

Lionfish; Invasive Species; Connectivity; Trap Bycatch; Habitat Preferences

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