Spatial Distribution of Reef-associated Fish in the Northeastern Gulf of Mexico: An Active Acoustics Approach

Authors

Allison Lynn WhiteFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Biology

First Advisor's Name

Kevin Boswell

First Advisor's Committee Title

committee chair

Second Advisor's Name

Yuying Zhang

Second Advisor's Committee Title

committee member

Third Advisor's Name

Yannis Papastamatiou

Third Advisor's Committee Title

committee member

Fourth Advisor's Name

Alastair Harborne

Fourth Advisor's Committee Title

committee member

Fifth Advisor's Name

Jennifer Rehage

Fifth Advisor's Committee Title

committee member

Sixth Advisor's Name

Patrick Sullivan

Sixth Advisor's Committee Title

committee member

Keywords

fisheries acoustics, reef fish, artificial reefs, survey design, geostatistics, generalized additive models, machine learning, spatial ecology

Date of Defense

3-28-2023

Abstract

The extensive reef systems along the western coast of Florida have been subjected to several anthropogenic disturbances in recent years. Information required to assess the impacts of these disturbances on reef fishes is currently limited in the northeastern Gulf of Mexico (nGOM), as the structural complexity of reefs make them an untrawlable habitat. Active acoustic surveys have widely been accepted as a non-invasive and time-effective alternative to traditional methods of pelagic fisheries sampling. At reefs, acoustic methods are currently limited in sampling mixed-assemblage communities due to the inability to provide species-level taxonomic description. Furthermore, reef fish aggregate over discrete spatially-resolved locations which may or may not be predictable. This provides a challenge in water column sampling, such as active acoustics, which aims to maximize the proportion of surveyed area which passes over the fish aggregation. In this dissertation, I applied active acoustics within these limitations to measure the spatial distribution of reef fish biomass in the nGOM. First, I utilized a multi-frequency acoustic approach to make direct comparisons of the horizontal (latitude and longitude) and vertical (depth in the water column) distribution of backscatter from swim-bladdered vii fishes at natural and artificial reefs along the northwestern Florida continental shelf. The effects of vertical relief, deployment depth, and area of influence on fish biomass around artificial reefs provide an indicator of the performance of artificial reefs as a mitigation tool for the loss of natural reef habitat. Next, I evaluated the precision in quantifying simulated and empirical backscatter of goliath grouper (Epinephalus itajara) spawning aggregations from commonly used survey designs and model-based inference approaches. In my last chapter, I integrated machine learning with acoustic methods and a towed camera array to classify fishery important fishes from non-targeted species at the Florida Middle Grounds, a series of high-profile limestone escarpments along the West Florida Shelf. My ultimate aim in the previous three approaches is to improve the practice of acoustic monitoring of reef-associated fishes and provide managers with baseline information about the spatial distribution of reef fishes in the nGOM.

Identifier

FIDC011005

Previously Published In

White, A., Patterson, W. F. III, and Boswell, K. M. 2022. Distribution of acoustic fish backscatter associated with natural and artificial reefs in the northeastern Gulf of Mexico. Fisheries Research 248 106199.

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.

Recommended Citation

White, Allison Lynn, "Spatial Distribution of Reef-associated Fish in the Northeastern Gulf of Mexico: An Active Acoustics Approach" (2023). FIU Electronic Theses and Dissertations. 5318.
https://digitalcommons.fiu.edu/etd/5318