Genetic monitoring as a promising tool for investigating fish habitat connectivity

Abstract

With approximately 92000 obstacles to flow identified in France, restoring the connectivity of fish habitats is today one of the main challenges of public environmental policies. Although restoration priorities are clearly defined, the assessment methods for analyzing connectivity issues are not subject to any specific regulations. Different approaches can thus be adopted in order to assess the barriers to fish mobility present in a watershed. The purpose of this paper is to present the potential of molecular biology tools to address habitat fragmentation issues. Through the presentation of the foundations and principles of application of population genetics, we will see how genetic data can facilitate the understanding of connectivity mechanisms and allow the identification of blocking points on a dendritic network. We will present two case studies on brown trout, illustrating how genetic data can be used as a decision support and diagnostic tool in the implementation of connectivity restoration programs.