Graduation Year

2026

Document Type

Thesis

Degree

M.S.

Degree Name

Master of Science (M.S.)

Degree Granting Department

Marine Science

Major Professor

Christopher Stallings, Ph.D.

Committee Member

Cameron Ainsworth, Ph.D.

Committee Member

William Patterson, Ph.D.

Keywords

Anthropogenic influences, Fisheries ecology, Habitat disturbance, West Florida shelf

Abstract

Globally, marine ecosystems are increasingly threatened by anthropogenic stressors, leading to reef degradation, changes in reef-fish assemblages, and altered trophic structure. In this study, I investigated reef-fish underwater visual survey data collected over a decade (2013-2023) from paired natural and artificial reefs in the eastern Gulf of Mexico. I applied the novel Normalized Reef Status Index (NRSI) to evaluate how biomass was distributed across the three trophic categories (i.e., Lower Trophic Position (LTP; 2.0-2.9), Central Trophic Position (CTP; 3.0-3.9), and Upper Trophic Position (UTP; ≥4.0). This index is a metric to assess the ecological status of reef systems by investigating the trophic structure of associated reef-fish assemblages. Specifically, it extends omnibus measures of standing biomass with a measure of biomass distribution among trophic positions. My results revealed the trophic structure of reef-fish assemblages differed across reef types (natural or artificial) and depths (shallow or deep). I observed no distinct seasonal or long-term interannual variations. However, I noted the presence of a downward trend in NRSI values on artificial reefs from 2020 to 2023, possibly due to increased recreational fishing activity during the SARS-CoV-2 (COVID-19) pandemic. These findings support the idea that using novel assessment tools, such as the NRSI, provides valuable insight into early signs of ecosystem degradation through biomass-based metrics, helping establish a current baseline as researchers continue to monitor marine systems.

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