Migrational Changes of Diadromous Fish in the San Francisco Bay Due to Anthropogenic Climate Change: A Correlational Research Study

Abstract

Recently, there has been consistent research within the field of environmental science focused on anthropogenic, or human-caused, climate change and understanding its trends and causes. Similarly, much of this research has been focused on its effects and understanding what can be done to mitigate those effects. Rising oceans, melting glaciers, and changes in weather patterns are some of the overarching impacts within the focus of this field. However, a similar, understudied effect is how climate change affects the migration of species, specifically, the migration of diadromous fish species. Diadromous refers to marine species that migrate between freshwater and saltwater within their lifetime in order to feed or spawn. Within this study, the research focuses specifically on the San Francisco Bay in California, United States, with the bay being not only defined as the saltwater that makes it up, but also the various rivers and estuaries that surround it, to which diadromous fish migrate to or from. In the San Francisco Bay, this study focuses on three diadromous species: the coho salmon, Chinook salmon, and steelhead trout. In order to understand these three species’ changes in migratory patterns, a correlational design using quantitative data was performed by running T-tests on each of the species. The T-tests compared the temperature of the bay from 2014 to 2024 to the optimal temperatures for migration of each of the species’ populations. The results gave insight into the potential for species’ migration to be altered depending on the amount of time they were outside of their optimal range.