Landscape and seascape genetics use population genetic concepts to explore how abiotic factors (ocean currents, temperature) affect gene flow between populations. Understanding how environmental factors affect gene flow can, in turn, inform the design of protected areas and corridors through which individuals can move. This is especially urgent in extremely fragmented habitats where loss of population connectivity can lead to inbreeding depression and elevated risks of localized extinction. Marine ecosystems differ from their terrestrial counterparts owing to the dynamic nature of the ocean. Traditional landscape genetic studies investigate how population connectivity is affected by minimum, maximum, or average values for environmental variables such as terrain, vegetation cover, or elevation, which do not rapidly change. However, abiotic factors that affect gene flow in marine environments, such as salinity or ocean current, are in constant flux because of variation in temperature, sea level, and wind. Understanding how these dynamic factors affect gene flow is a challenge because traditional landscape genetic techniques cannot account for this variation. My research uses methods adapted from physical oceanography to estimate the connectivity between populations via ocean currents while including the inherent variability of the marine environment. I use this estimate connectivity with genetic data to evaluate the role ocean currents play in driving patterns of gene flow between populations.
The two photos above demonstrate the general ocean current trend (left) and the extreme variability in ocean currents across seasons (right). The map on the right demonstrates the drastic changes in both direction of the ocean currents and strength (length of the arrows). Furthermore, salinity is defined by color and can be extremely different, depending on your location, between seasons.