Publication Date

2016-12-14

Availability

Open access

Embargo Period

2016-12-14

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Marine Affairs and Policy (Marine)

Date of Defense

2016-10-20

First Committee Member

Neil Hammerschlag

Second Committee Member

Elizabeth Babcock

Third Committee Member

Maria Estevanez

Abstract

Restoration and monitoring are important conservation tools to ensure the recovery and maintenance of human impacted habitats. Bill Baggs Cape Florida State Park, located in Key Biscayne, Florida, has been impacted by urban development and hurricanes, leading to the historical removal of much of the park’s native habitat, including mangrove forest. After Hurricane Andrew in 1992, restoration efforts led to the replanting of a 30-hectare mangrove forest within the park. Part of the forest’s design involved incorporating a series of 28 mangrove pools within the forest to act as nursery habitat. While there have been several studies examining fish using the mangrove pools early on in the forest’s recovery, no work regarding fish abundance and richness in this recovering habitat has been done in over ten years. This study examines the current relative abundance, richness, and trophic levels of fish within the restored mangrove pools and compare the current fish assemblage with historical data, and evaluates the potential impact of environmental factors on fish abundance and richness in the restored pools. To address these research goals, seven mangrove pools were sampled using BRUVS (baited remote underwater video stations) to establish the current abundance and richness of fish utilizing the pools. A subsample of BRUVS and seine was conducted to determine potential differences in fish families and feeding guilds observed between the techniques. This comparison was then assessed to examine the validity of statistically comparing historical data from previous studies (seine net sampling) to the current study (BRUVS sampling). Environmental data was also collected during each sampling for comparison against patterns of fish presence and abundance. 464 individual fish were observed over the course of BRUVS sampling. 20 taxa were observed, consisting of five families, two genera, and 13 species. Four of these species were not observed in any of the previous studies: nurse shark (Ginglymostoma cirratum), mangrove gambusia (Gambusia rhizophorae), sailfin molly (Poecilia latipinna), and schoolmaster snapper (Lutjanus apodus). The fish observed via BRUVS were categorized into three feeding guild: zoobenthivores, piscivores, and planktivores. There was a significant difference in the presence and abundance of fish families observed between BRUVS and seine but not between feeding guilds. While the current BRUVS sampling cannot be statistically compared to previous work seine sampling conducted in the park, the higher CPUE of hardhead silversides and goldspotted killifish from seine sampling in the current study indicates an increase in abundance of these ecologically important forage fish. No single environmental factor affected the presence and abundance of all fish families and feeding guilds. However, individual pools and turbidity emerged as significant factors in several instances. The presence of nursery species, occurrence of predatory species and increased abundance of small forage fish in the present study indicates that the mangrove fringed pools is acting as habitat for variety of economically and ecologically important species. Low species richness in comparison to natural forests in adjacent Biscayne Bay suggest that the young forest is still recovering as essential fish habitat and function not yet fully restored.

Keywords

replanted mangrove; habitat restoration; fish habitat; species richness; biodiversity; nursery habitat

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