Does river channelization increase the abundance of invasive crayfish? Survey of Faxonius limosus in small Central European streams

Rafał Bobrek,Maciej Bonk

doi:10.1007/s11356-021-12750-y

Abstract

The aim of this study was to assess whether regulated river reaches show higher numbers of the spiny cheek crayfish Faxonius limosus, a common freshwater invader in Europe. Man-made alterations of riverine habitats may increase their susceptibility to biological invasions. This phenomenon is commonly studied in the context of dam reservoirs; however, the impact of river channelization and the resulting riverine habitat homogenization on the success of invasive species are mostly lacking. Surveys were conducted in natural and channelised river stretches in five rivers of south-central Poland. General linear mixed model analysis showed that crayfish abundance is usually higher at sites located within regulated reaches. The likely reason for the detected differences in abundance of crayfish may be related to decreased food-web complexity and lack of predators in a homogenised habitat. The results suggest that the channelization of small watercourses may increase the abundance of invasive species F. limosus and its pressure on native European crayfish. However, due to limited data obtained in field, our study should be considered as a pilot one.

Highlights

Biological invasions are a major issue for the economy (Perrings et al 2002) and in nature conservation (McGeoch et al 2016)
The regulations include dam reservoirs and other impoundments resulting in turning formerly lotic habitats into lentic ones, and river channelization, resulting in the elimination of natural meanders, making rivers straighter and shorter than in native state. These actions lead to riverine habitat homogenization (Elosegi et al 2010)
It has been demonstrated that dam reservoirs are highly invasible (Johnson et al 2008; Liew et al 2016) and may act as hubs for invaders—for example, Environ Sci Pollut Res (2021) 28:31831–31837 the abundance of such species decreases with increasing distance to impoundment (Light 2003)

Summary

Introduction

Biological invasions are a major issue for the economy (Perrings et al 2002) and in nature conservation (McGeoch et al 2016). The regulations include dam reservoirs and other impoundments resulting in turning formerly lotic habitats into lentic ones, and river channelization, resulting in the elimination of natural meanders, making rivers straighter and shorter than in native state. These actions lead to riverine habitat homogenization (Elosegi et al 2010). River channelization, eliminating the majority of natural hydromorphological elements, is less studied in the context of biodiversity than dam reservoirs (Aarts et al 2004; Figarski and Kajtoch 2015) Despite numerous papers documenting the invasions of alien plants along altered river channels or valleys in terrestrial habitats (e.g. Mortenson and Weisberg 2010; Catford et al 2011), there is a lack of knowledge about the invasion process within watercourses

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