Master’s Defense

Epifaunal macroinvertebrates, or biofouling communities are an often-overlooked aspect of broader community biodiversity and species composition. Characterizing and measuring community composition on a thorough scale is crucial to understanding the health and function of coastal ecosystems. Anthropogenic activities in coastal waters create novel substrates for these epifaunal communities to populate, and in the south Texas bays characterized by primarily soft bottoms, efforts must be taken to identify the species in these biofouling communities. This study aimed to characterize these biofouling communities in the Mission-Aransas Estuary located on the southern Gulf Coast of Texas. Using different sites throughout the estuary, two separate seasonal deployments, and treatments with different exposure to motile predators resulted in a broad understanding of how these communities vary across time and space. Traditional efforts to identify these communities consist of visual analyses, in-situ observations and photo identification, this study used community metabarcoding in addition to photo identification to investigate the benefits of each methodology. Community metabarcoding resulted in higher taxonomic resolution, when compared to the photo id, but it was not comprehensive and omitted an entire phylum observed visually. This study showed that there are seasonal and spatial signals affecting the recruitment and settlement of biofouling organisms in the Mission-Aransas Estuary, however, there was no effect of predation pressure observed across the deployments or sites when using cages to manipulate motile predator access to the developing communities. Continuing the monitor the communities associated with anthropogenic infrastructure may lead to early detection and management of new and introduced species, additionally characterizing the biofouling communities creates a baseline for future studies to understand how the resiliency of these species may be beneficial as estuaries continue to face increasing threats from both people and the climate.