The effects of non-native signal crayfish (Pacifastacus leniusculus) on fine sediment and sediment-biomonitoring

Matthew Turley, Gary Bilotta, Antonio Gasparrini, Francesco Sera, Kate Mathers, Ian Humpheryes, Judy England

Research output: Contribution to journalArticle

Abstract

The North American signal crayfish (Pacifastacus leniusculus) has invaded freshwater ecosystems across Europe. Recent studies suggest that predation of macroinvertebrates by signal crayfish can affect the performance of freshwater biomonitoring tools used to assess causes of ecological degradation. Given the reliance on biomonitoring globally, it is crucial that the potential influence of invasive species is better understood. Crayfish are also biogeomorphic agents, and therefore, the aim of this study was to investigate whether sediment-biomonitoring tool outputs changed following signal crayfish invasions, and whether these changes reflected post-invasion changes to deposited fine sediment, or changes to macroinvertebrate community compositions unrelated to fine sediment. A quasi-experimental study design was employed, utilising interrupted time series analysis of long-term environmental monitoring data and a hierarchical modelling approach. The analysis of all sites (n= 71) displayed a small, but statistically significant increase between pre- and post-invasion index scores for the Proportion of Sediment-sensitive Invertebrates (PSI) index biomonitoring tool (4.1,p< 0.001, 95%CI: 2.1, 6.2), which can range from 0 to 100, but no statistically significant difference was observed for the empirically-weighted PSI (0.4,p= 0.742, 95%CI: − 2.1, 2.9), or fine sediment (− 2.3,p= 0.227, 95%CI: − 6.0, 1.4). Subgroup analyses demonstrated changes in biomonitoring tool scores ranging from four to 10 percentage points. Importantly, these subgroup analyses showed relatively small changes to fine sediment, two of which were statistically significant, but these did not coincide with the expected responses from biomonitoring tools. The results suggest that sediment-biomonitoring may be influenced by signal crayfish invasions, but the effects appear to be context dependent, and perhaps not the result of biogeomorphic activities of crayfish. The low magnitude changes to biomonitoring scores are unlikely to result in an incorrect diagnosis of sediment pressure, particularly as these tools should be used alongside a suite of other pressure-specific indices.
Original languageEnglish
Pages (from-to)186-193
Number of pages8
JournalScience of the Total Environment
Volume601-60
DOIs
Publication statusPublished - 25 May 2017

Fingerprint

biomonitoring
crayfish
sediment
macroinvertebrate
invertebrate
effect
freshwater ecosystem
time series analysis
environmental monitoring
invasive species
community composition
experimental study
predation
degradation

Bibliographical note

© 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).

Keywords

  • Deposited fine sediment
  • Macroinvertebrates
  • Invasive species
  • Interrupted time series analysis
  • Biogeomorphology
  • Ecological assessment

Cite this

Turley, Matthew ; Bilotta, Gary ; Gasparrini, Antonio ; Sera, Francesco ; Mathers, Kate ; Humpheryes, Ian ; England, Judy. / The effects of non-native signal crayfish (Pacifastacus leniusculus) on fine sediment and sediment-biomonitoring. In: Science of the Total Environment. 2017 ; Vol. 601-60. pp. 186-193.
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The effects of non-native signal crayfish (Pacifastacus leniusculus) on fine sediment and sediment-biomonitoring. / Turley, Matthew; Bilotta, Gary; Gasparrini, Antonio; Sera, Francesco; Mathers, Kate; Humpheryes, Ian; England, Judy.

In: Science of the Total Environment, Vol. 601-60, 25.05.2017, p. 186-193.

Research output: Contribution to journalArticle

TY - JOUR

T1 - The effects of non-native signal crayfish (Pacifastacus leniusculus) on fine sediment and sediment-biomonitoring

AU - Turley, Matthew

AU - Bilotta, Gary

AU - Gasparrini, Antonio

AU - Sera, Francesco

AU - Mathers, Kate

AU - Humpheryes, Ian

AU - England, Judy

N1 - © 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).

PY - 2017/5/25

Y1 - 2017/5/25

N2 - The North American signal crayfish (Pacifastacus leniusculus) has invaded freshwater ecosystems across Europe. Recent studies suggest that predation of macroinvertebrates by signal crayfish can affect the performance of freshwater biomonitoring tools used to assess causes of ecological degradation. Given the reliance on biomonitoring globally, it is crucial that the potential influence of invasive species is better understood. Crayfish are also biogeomorphic agents, and therefore, the aim of this study was to investigate whether sediment-biomonitoring tool outputs changed following signal crayfish invasions, and whether these changes reflected post-invasion changes to deposited fine sediment, or changes to macroinvertebrate community compositions unrelated to fine sediment. A quasi-experimental study design was employed, utilising interrupted time series analysis of long-term environmental monitoring data and a hierarchical modelling approach. The analysis of all sites (n= 71) displayed a small, but statistically significant increase between pre- and post-invasion index scores for the Proportion of Sediment-sensitive Invertebrates (PSI) index biomonitoring tool (4.1,p< 0.001, 95%CI: 2.1, 6.2), which can range from 0 to 100, but no statistically significant difference was observed for the empirically-weighted PSI (0.4,p= 0.742, 95%CI: − 2.1, 2.9), or fine sediment (− 2.3,p= 0.227, 95%CI: − 6.0, 1.4). Subgroup analyses demonstrated changes in biomonitoring tool scores ranging from four to 10 percentage points. Importantly, these subgroup analyses showed relatively small changes to fine sediment, two of which were statistically significant, but these did not coincide with the expected responses from biomonitoring tools. The results suggest that sediment-biomonitoring may be influenced by signal crayfish invasions, but the effects appear to be context dependent, and perhaps not the result of biogeomorphic activities of crayfish. The low magnitude changes to biomonitoring scores are unlikely to result in an incorrect diagnosis of sediment pressure, particularly as these tools should be used alongside a suite of other pressure-specific indices.

AB - The North American signal crayfish (Pacifastacus leniusculus) has invaded freshwater ecosystems across Europe. Recent studies suggest that predation of macroinvertebrates by signal crayfish can affect the performance of freshwater biomonitoring tools used to assess causes of ecological degradation. Given the reliance on biomonitoring globally, it is crucial that the potential influence of invasive species is better understood. Crayfish are also biogeomorphic agents, and therefore, the aim of this study was to investigate whether sediment-biomonitoring tool outputs changed following signal crayfish invasions, and whether these changes reflected post-invasion changes to deposited fine sediment, or changes to macroinvertebrate community compositions unrelated to fine sediment. A quasi-experimental study design was employed, utilising interrupted time series analysis of long-term environmental monitoring data and a hierarchical modelling approach. The analysis of all sites (n= 71) displayed a small, but statistically significant increase between pre- and post-invasion index scores for the Proportion of Sediment-sensitive Invertebrates (PSI) index biomonitoring tool (4.1,p< 0.001, 95%CI: 2.1, 6.2), which can range from 0 to 100, but no statistically significant difference was observed for the empirically-weighted PSI (0.4,p= 0.742, 95%CI: − 2.1, 2.9), or fine sediment (− 2.3,p= 0.227, 95%CI: − 6.0, 1.4). Subgroup analyses demonstrated changes in biomonitoring tool scores ranging from four to 10 percentage points. Importantly, these subgroup analyses showed relatively small changes to fine sediment, two of which were statistically significant, but these did not coincide with the expected responses from biomonitoring tools. The results suggest that sediment-biomonitoring may be influenced by signal crayfish invasions, but the effects appear to be context dependent, and perhaps not the result of biogeomorphic activities of crayfish. The low magnitude changes to biomonitoring scores are unlikely to result in an incorrect diagnosis of sediment pressure, particularly as these tools should be used alongside a suite of other pressure-specific indices.

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KW - Macroinvertebrates

KW - Invasive species

KW - Interrupted time series analysis

KW - Biogeomorphology

KW - Ecological assessment

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DO - 10.1016/j.scitotenv.2017.05.106

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JO - Science of the Total Environment

JF - Science of the Total Environment

SN - 0048-9697

ER -