Date of Award
2024
Degree Type
Thesis
Degree Name
Master of Science in Biological and Environmental Sciences (MSBES)
First Advisor
Carlos Prada
Abstract
Coastal ecosystems are degrading rapidly, and molecular analysis of environmental DNA (eDNA) has become an increasingly popular method to quantify changes in biodiversity, and as a powerful and affordable complement to monitor aquatic environments. Yet, side by side comparisons of biodiversity estimates from eDNA and other traditional methods are needed to understand the level of accuracy of the eDNA method. We used eDNA metabarcoding of the 12S mitochondrial gene to generate a multi-species fish biodiversity assessment of Narragansett Bay (NB). Here we estimated biodiversity using eDNA data and compared it to conventional seine surveying data. We then further estimate biodiversity in NB across seasons and finer spatial scales using eDNA, to quantify species composition in NB. When compared to coastal seine surveying, eDNA has similar biodiversity estimates throughout Narragansett Bay, and the eDNA approach detects changes in species composition across seasons. Surprisingly, the number of reads generated through eDNA, and fish density captured with seine surveying are positively correlated, suggesting some value in the eDNA approach to not only capture changes in species composition, but also quantitative estimates per species. We also found substantial differences among seasons in the composition of NB fish communities. Using eDNA, we identified 46 species of fish in winter, 47 species in autumn, 35 species in spring, and 41 species in summer. Historically winter has been considered to have less biodiversity, however; our results suggest including winter in sampling efforts can improve our understanding of NB. eDNA is a powerful approach to capture community shifts effectively across environmental gradients and seasons, both in compliment and as an alternative approach to traditional methods; especially in areas that are threatened by long term human interference and climate change. The added correlational aspect of eDNA copies with fish quantities is a promising prospect for the management of marine ecosystems.
Recommended Citation
Mora, Juliane, "USING EDNA AND TRADITIONAL METHODS TO ASSESS FISH DIVERSITY IN NARRAGANSETT BAY" (2024). Open Access Master's Theses. Paper 2498.
https://digitalcommons.uri.edu/theses/2498