Spatial variation in the somatic growth rates of European barbel Barbus barbus: a UK perspective

Abstract

The European barbel Barbus barbus is threatened in areas of its range because of its sensitivity to anthropogenic disturbance in riverine habitats and, in the UK, is indigenous to a relatively small number of eastflowing rivers, with nonindigenous populations present in other rivers following introductions for angling enhancement. Fish stock assessment surveys completed between 2002 and 2010 collated age and growth data from 20 rivers across their indigenous and nonindigenous UK range. Analyses revealed that individuals present in samples are of 21 years old, with growth rates highly variable between rivers. There was no relationship between growth rates and the maximum age of fish per river, and there was no difference in growth rates between their indigenous and nonindigenous ranges. A range of abiotic data were collated and analysed against the growth data; these analyses suggested higher mean growth rates were evident in rivers of higher biological water quality (expressed as British Monitoring Working Party Score) and higher mean air temperatures (used as a surrogate of water temperature). That growth of B. barbus was significantly and positively enhanced by increased biological water quality was in contrast to cyprinid fishes such as roach Rutilus rutilus and suggests that as river water quality continues to improve through reduced nutrient inputs, further ecological changes are likely in riverine fish communities.

Influences of environmental and chemical parameters on the spatial growth patterns of four riverine cyprinid fishes

“…river flow, temperature) and changes in water chemistry (e.g. nutrient enrichment arising from anthropogenic disturbances) tend to be more important influences on fish ecology generally and growth specifically (Lappalainen et al, 2008;Britton et al, 2013). Spatially, the influence of latitude on water temperature is recognised as a major determinant of fish growth rates in the northern hemisphere (Blanck and Lamouroux, 2007;Lappalainen et al, 2008;Carmona-Catot et al, 2011), with a general pattern of reduced growth with increased latitude due to lower temperatures and shorter growth seasons ( (Blanck and Lamouroux 2007;Lappalainen et al, 2008;Carmona-Catot et al, 2011).…”

Spatial variability in the growth of invasive European barbel Barbus barbus in the River Severn basin, revealed using anglers as citizen scientists

“…Thus, the limited sample sizes of the current study are a potential concern in terms of the precision of the growth data and so should be treated with some caution, but with the caveat that supplementing these samples with greater numbers of fish would be highly challenging. Despite these inherent issues with sample sizes and fish lengths, the scale samples indicated that individual fish were present in the rivers to at least 20 years old, and potentially older given the inherent difficulties of ageing of large, slow growing B. barbus from scales (Britton and Pegg, 2011;Britton et al, 2013). The growth data then indicated that differences in the growth rates of the fish between the reaches were primarily in relation to their adult growth and ability to grow to large body sizes.…”

“…Whilst there was a series of studies completed on B. barbus invasion biology in the River Severn from samples collected in the 1960s (e.g. Hunt and Jones, 1975), there has been limited study of this population since (Britton et al, 2013). This is despite their presence over a wide range of physical habitats, ranging from narrow and shallow sections of the River Teme to impounded, deep and slow flowing sections of the lower Severn.…”

“…1). The species has since been an important component of angler catches in both rivers (North, 1980;North and Hickley, 1989;Britton et al, 2013). Whilst there was a series of studies completed on B. barbus invasion biology in the River Severn from samples collected in the 1960s (e.g.…”

“…More recent applications include non-lethal tissue sampling for genetics (Williams et al, 2015;Guindon et al, 2015) and stable isotope analysis (Basić et al, 2015;Basić and Britton, 2016). Given the frequent difficulty of obtaining ecological information on B. barbus in large rivers using regular sampling methodologies such as electric fishing (Britton et al, 2013), then the use of angling within data collection approaches could provide considerable benefit. Thus, the aim here was to analyse the spatial variability of the age and growth rates of invasive B. barbus in the Rivers Severn and Teme utilising scales collected by electric fishing and supplemented by angler catches.…”