Abstract

Coastal habitats provide crucial nursery habitat for predatory fishes, but they are in decline worldwide, impacting economically important fisheries. Habitat restoration can simultaneously mitigate the effects of habitat loss and benefit predators (e.g., sportfish), although this relationship is understudied. Here, the response of juvenile sportfish to oyster reef and living shoreline restoration is compared to controls in the Indian River Lagoon, Florida prior to and following restoration for up to three years through examination of community (diversity, assemblage), population (abundance), biometric (size, body condition), ontogenetic, and trophic (gut contents, stable isotopes) dynamics. Stable isotopes were used to quantify dietary history, beyond the temporary record of gut content, using carbon (δ13C) and nitrogen (δ15N). This study found juvenile sportfish abundance and richness was higher at restored reefs compared to natural and degraded reefs and was comparable between stabilized and natural living shorelines. Biomass was higher at oyster reefs compared to living shorelines, which was likely driven by an ontogenetic shift of larger mangrove snapper Lutjanus griseus toward oyster habitat. Snappers and prey at live reefs were carbon (δ13C) enriched, with a smaller isotopic niche area compared to dead reefs, while restored reefs were intermediate and contracted over time. Therefore, sportfish at higher quality reefs likely exhibit greater site fidelity, particularly among less-mobile juveniles. Moreover, stabilized shorelines can achieve trophic equivalence to natural shorelines, as shown through their similar isotopic signatures and niche area. These responses were best predicted by benthic habitat (e.g., oyster density), prey abundances, and site location, demonstrating the connection between habitat quality and setting to provide prey that support sportfish populations. This study validates the benefits of habitat restoration to economically important fisheries, by augmenting various attributes of juvenile sportfish life history, which can improve their survival and recruitment into the adult population, and thus extend restoration outcomes.

Notes

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Graduation Date

2022

Semester

Spring

Advisor

Cook, Geoffrey

Degree

Doctor of Philosophy (Ph.D.)

College

College of Sciences

Department

Biology

Degree Program

Conservation Biology

Format

application/pdf

Identifier

CFE0009016; DP0026349

URL

https://purls.library.ucf.edu/go/DP0026349

Language

English

Release Date

May 2023

Length of Campus-only Access

1 year

Access Status

Doctoral Dissertation (Open Access)

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