Estimating the dispersal capacity of Scottish blue mussel (Mytilus edulis): From hydrodynamic modelling to genetic population structures

Abstract

The blue mussel (Mytilus edulis) and the Mediterranean mussel (Mytilus galloprovin- cialis) are the primary bivalve species in Europe, with France and Spain being the top producers. In recent years, Scotland has also seen a significant increase in mussel pro- duction due to a higher settlement of mussel larvae onto suitable surfaces, which is crucial for cultivation. However, despite the growth of natural spatfall, limited re- search on mussel farming methods in dynamic areas has led to inefficiencies and fluc- tuations in production. As a result, there is a pressing need for improved management practices to ensure sustainable growth in the industry. This study seeks to address knowledge gaps concerning mussel dispersion, crucial for effective mussel farming management, by investigating population genetics and em- ploying hydrodynamic modelling. Presented is a comprehensive genome assembly of the blue mussel, M. edulis, identifying multiple whole genome duplication events. This assembly facilitates the development of precise genetic markers, contributing to an improved understanding of the intricate genetic structure of Scottish mussel popu- lations. Additionally, the study utilises a biophysical model to illustrate the high con- nectivity of M. edulis populations, influenced by the rapid water currents and wind direction on Scotland’s dynamic West Coast. This interdisciplinary approach inte- grates population genomics and biophysical modeling, providing valuable insights into various mussel farming areas across Scotland. The findings suggest that understanding the connectivity of mussel populations and the gene flow is essential for effective management practices. The population study shows a mussel gene flow between key areas, leading to a rapid change in local pop- ulations, exemplified by the noticeable alteration of genotypes from one generation to the next. The ocean currents help mussels move around and spread their genes, which creates a complicated network of mussel populations. By understanding this connectivity, mussel farmers can make informed decisions on stocking and harvesting strategies to ensure the sustainability of mussel farming practices in the long term.