Unlocking the secret life of blue mussels: Exploring connectivity in the Skagerrak through biophysical modeling and population genomics
Knowledge of where functional dispersal barriers are located in the marine environment can be used to inform a wide variety of management actions, such as marine spatial planning, restoration efforts, fisheries regulations and invasive species management. Locations and causes of dispersal barriers can be studied through various methods, including movement tracking, biophysical modeling, demographic models and genetics. In particular, combining methods illustrating potential dispersal, such as biophysical modeling, with realized dispersal through e.g. genetic connectivity estimates, provides useful information for teasing apart potential causes of observed barriers. In this study, we focus on blue mussels (Mytilus edulis) in the Skagerrak, a marginal sea connected to the North Sea in Northern Europe, and combine biophysical models of larval dispersal with genomic data to infer locations and causes of dispersal barriers in the area. Results from both methods agree, indicating that current patterns are a major structuring factor in the area. We find a complex pattern of source-sink dynamics with several dispersal barriers, and show that some areas can be isolated despite an overall high dispersal capability. Finally, we translate our finding into management advice, in order to sustainably manage this ecologically and economically important species in the future.