Knowledge and Management of Aquatic Ecosystems (KMAE) serves as a foundation for scientific advice across the broad spectrum of management and conservation issues related to freshwater ecosystems. This special issue aims to address this knowledge gap by promoting studies that assess the ecological, evolutionary and environmental implications of floating photovoltaics and their implications.

Belonging to the genus Salmo, the Atlantic Salmon is a species in the family Salmonidae and the subfamily Salmoninae. The Atlantic Salmon is still present in numerous rivers of the French Channel-Atlantic seafront. It has always been absent from the Mediterranean. The overall objective of this guide is to serve as a user manual for interpreting the scales and estimating the age of the Atlantic Salmon (Salmo salar) from the French Atlantic Salmon populations.

Invasive alien species (IAS) and their impacts represent a growing concern for the managers of natural areas. In both continental France and the overseas territories, a large number of people and organisations have taken action to limit the damage. Following on from the previous works, volume 4 brings together 25 unpublished project management reports in aquatic and terrestrial environments, including 8 in the French overseas territories.

What lessons may be drawn from the implementation of SNB 2011-2020? What methods should be selected for SNB3 (after 2020), notably in terms of the types of action and the governance of the strategy? To answer these questions, the French Biodiversity Agency and the Ecology Ministry requested an assessment of the strategy, including a retrospective analysis (public-policy evaluation) and a forward-looking analysis.

CDC Biodiversité develops the Global Biodiversity Score (GBS), a corporate biodiversity footprint assessment tool, to evaluate the impact of companies and investments on biodiversity at a corporate level. CDC Biodiversité and the French Biodiversity Agency (Office français de la biodiversité, OFB) want the tool to go through an independent review.

Calling on the experience gained in deploying the Information on the continuity of ecosystems (ICE) method in continental France and in a partnership with all the overseas Environmental Directorates and Water Offices, OFB coordinated and facilitated the adaptation of the method to the tropical islands of Guadeloupe, Martinique, Mayotte and Réunion.

Natural water retention measures comprise an array of initiatives to restore the natural properties of ecosystems in view of slowing the runoff of surface waters and increasing the infiltration capacity of soil. Examples from projects in France stress the multiple benefits of these measures.

The French National River Restoration Centre, led by the French Agency for Biodiversity (AFB), organised a workshop and field visits on river continuity restoration initiatives. This was an opportunity for practitioners involved in the management of aquatic environments to discover reproducible actions targeting multiple issues, carried out in Italy, the United Kingdom, Finland and France.

Three biological forms of brown trout, river, lake and sea, have colonised a large number of aquatic environments in France, owing to a high ecological plasticity of the species. The overall objective of this guide is to serve as a user manual for interpreting the scales and estimating the age of brown trout (Salmo trutta) from the French trout populations.

This guideline is designed as a toolkit to support stakeholders and designers in the completion of constructed wetlands (CW) projects in tropical and equatorial climate zones.