Mesohabitat modelling in fish ecology: A global synthesis

Abstract

Modelling the linkage between physical habitat and aquatic organisms on multiple spatial scales has become an important tool in the management of rivers. The mesoscale (100–102 m) represents an intermediate resolution in modelling that bridges the gap between available resources and conservation efforts for riverine species. However, existing mesohabitat classification schemes for lotic systems vary significantly in the definition of habitat types as well as in their application in the field. This article aims to provide an overview of current attempts to model the mesoscale pattern of physical habitats with a focus on fish. First, we outline descriptive, qualitative as well as objective, quantitative classification methods that are available in the literature. Next, the ecological relevance of the mesohabitat concept is being discussed, using single‐species and community‐level approaches as examples. Different modelling approaches that describe and quantify riverine mesohabitats are presented, and finally, limitations and uncertainties in the modelling process are discussed, followed by an outline of future perspectives in mesohabitat modelling.

Environmental drivers of benthic fish assemblages and fish‐habitat associations in offshore areas of a very large river

“…Further, variation in velocity was coupled with variation in mean depth and substratum composition (i.e., Shannon diversity of sediment composition) and higher proportion of silt material. These results thus show that offshore areas which are mostly considered as homogenous mesoscale-level units in fish habitat evaluations (Baranya et al, 2018;Habersack, Tritthart, Liedermann, & Hauer, 2014;Wegscheider, Linnansaari, & Curry, 2020) do show some clearly recognizable environmental heterogeneity. However, the hierarchical evaluations and visualization of physical data also show that most offshore environmental heterogeneity occurs at the macroscale (10 4 -10 5 m) that is between larger river segments in the Middle-Danube, and that within mesoscale level (i.e., between sample units within transects) environmental heterogeneity is relatively low offshore.…”

Enhancing an unsupervised clustering algorithm with a spatial contiguity constraint for river habitat analysis

“…In recent years, the mesoscale is increasingly being used for river habitat analysis (e.g., Legleiter & Goodchild, 2005; Hauer et al, 2009; Wyrick et al, 2014; Tamminga & Eaton, 2018; O'Sullivan et al, 2020), and its use will likely increase in the future (Wegscheider et al, 2020). On this scale, it is necessary to identify patches, which form the basis on which the habitat analysis is built.…”

“…The mesoscale is of practical interest for river management (Gosselin et al, 2010; Newson & Newson, 2000; Wegscheider et al, 2020), and many restoration projects have a spatial scale where the mesoscale is most impacted. Additionally, the mesoscale patches can be used in a riverscape framework to identify metrics like connectivity and population dynamics (Carbonneau et al, 2012; Fausch et al, 2002; Wiens, 2002).…”

Relationship between Morphological Characteristics and Quality of Aquatic Habitat in Mountain Streams of Slovakia

“…This relationship can be modelled, which allows a qualitatively higher level for a wide range of water management activities. Habitat modelling in fish ecology [8] provides one of the most comprehensive tools for scrutinizing the river potential to provide a favourable platform for river ecosystems and simultaneously proposes measures to improve the habitat [9]. Instream flow models connect a physical habitat model predicting hydraulic changes to a biological model predicting the response of fish to an altered velocity and depth.…”