Body size affects the vertical movement of benthic amphipods through subsurface sediments in response to drying

Charlie Patel, Atish Vadher*, Kate Mathers, Ciara Dwyer, Paul Wood

*Corresponding author for this work

Research output: Contribution to JournalArticlepeer-review


This study aimed to experimentally examine how riverbed drying and different rates of water level reduction influenced the vertical movement of amphipods of various sizes into different subsurface sediment compositions. Using sediment columns (mesocosms) filled with different sized transparent substrates, we explored how varying speeds of drawdown affected vertical movement and stranding of individuals. We hypothesised that: (1) larger individuals would be less able to migrate within subsurface sediments compared to smaller ones; (2) smaller sediment particles would lead to more individuals becoming stranded and; (3) faster rates of water level drawdown would increase the likelihood of individuals becoming stranded above the waterline. Body size significantly influenced the final position of an individual, with smaller individuals accessing deeper sediments more readily. Larger amphipods were more likely to become stranded above the waterline. Amphipods migrated to greater depths during faster water level reduction rates with smaller individuals displaying greater overall movement. Sediment particle size did not influence the ability of amphipods to move vertically into subsurface sediments in response to water level reduction. The results indicate that subsurface sediments may serve as a refuge from surface drying but that both the size of individual invertebrates influences their ability to migrate vertically.
Original languageEnglish
Pages (from-to)1015-1025
Number of pages11
Issue number5
Early online date3 Feb 2021
Publication statusPublished - 3 Feb 2021


  • Stream drying
  • sediment particle-size
  • macroinvertebrate
  • burrowing
  • head-width
  • water level reduction
  • Burrowing
  • Head-width
  • Water level reduction
  • Primary Research Paper
  • Sediment particle-size
  • Macroinvertebrate

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