Modelling functional fish habitat connectivity in rivers: A case study for prioritizing restoration actions targeting brown trout

Abstract

Throughout the world, decreased connectivity of fluvial habitats caused by artificial river channel alterations such as culverts, weirs and dykes is seen as an important threat to the long‐term survival of many aquatic species. In addition to assessing habitat quality and abundance, wildlife managers are becoming increasingly aware of the importance of taking into account habitat connectivity when setting priorities for restoration. In this paper, a new approach of spatial analysis adapted to rivers and streams is proposed for modelling 2D functional habitat connectivity, integrating distance, costs and risk of travelling between habitat patches (e.g. daily use, spawning, refuge) for particular fish species, size classes and life stages. This approach was applied to a case study in which brown trout (Salmo trutta) habitat accessibility was examined and compared under various scenarios of stream restoration in a highly fragmented stream in Ile‐de‐France. Probabilities of reaching spawning habitats were estimated from a trout‐populated area located downstream of the barriers and from potential daily‐use habitat patches across the stream segment. The approach successfully helped prioritize restoration actions by identifying options that yield the greatest increase in accessible spawning habitat areas and connectivity between spawning habitat and daily‐use habitat patches. This case study illustrates the practical use of the approach and the software in the context of river habitat management.

A Portfolio Framework for Prioritizing Conservation Efforts for Yellowstone Cutthroat Trout Populations

“…; Mantyka‐Pringle et al. ; Roy and Le Pichon ). Prioritization frameworks vary in spatial scale, scope, and the amount of qualitative and quantitative information used to formulate decisions.…”

Linking fish assemblages to hydro‐morphological units in a large regulated river

“…This is especially important when diadromous species are present, which can rely on a wide range of different habitat types to complete their life cycle (Fullerton et al, 2010; Wolter, Buijse, & Parasiewicz, 2016). Buddendorf, Malcolm, Geris, Wilkinson, and Soulsby (2017) and Roy and Le Pichon (2017) have recently demonstrated the importance of habitat connectivity for salmonids using modelling case studies. In addition, fish assemblage analysis based on life history strategies or ‘traits’ could provide additional information that might be lacking if the study is restricted only to taxonomic analysis (Schwartz, 2016; Wolter et al, 2016).…”

Fisheries Volume 43 Number 10 October 2018

“…The complexity of issues facing species and aquatic ecosystems has increasingly led to the development of frameworks to prioritize management and conservation actions (e.g., Maitland et al 2016 ;Mantyka-Pringle et al 2016 ;Roy and Le Pichon 2017 ). Prioritization frameworks vary in spatial scale, scope, and the amount of qualitative and quantitative information used to formulate decisions.…”