Ria Talwar

Explaining genetic variation in the Pacific white-sided dolphin with environmental factors

Started Oct. 28, 2022

Abstract or project description

Environmental changes driven by pollution and climate change have affected many species globally. The Pacific white-sided dolphin (Lagenorhynchus obliquidens)** is threatened by water pollution, which is the product of human actions and can impact the genetic structure of species in affected areas. While researchers have studied genetic differences between populations of L. obliquidens in Japan, they failed to explore the potential environmental drivers of these differences. Our research aimed to identify the major environmental factors impacting the genetics of L. obliquidens, which will increase our understanding of how the species responds to variations in the environment. Due to the significant presence and variation of microplastics in the ocean surrounding Japan, we hypothesized that this would have the most notable impact on the genetics of L. obliquidens. We began our research by gathering genetic sequencing data from a preexisting study focusing on populations along the Japanese coast. We collected environmental data and analyzed it alongside a genetic distance matrix, leveraging data analysis and machine learning tools in R. We created a distance-based redundancy analysis that indicated that current stability was the most important variable, which matched the results of a random forest machine-learning model using environmental data to predict genetic clusters, a binary category determined by the authors of the original study. We then investigated why current may have had such a strong impact on L. obliquidens and hypothesized that it has a connection to nutrient and prey distribution, which is something that ocean currents can have a major impact on.