Size matters: Effects of propagule size on dispersal in rivers

Biological particles (e.g., bacteria, eggs, fruit/seeds, and larvae) of a wide range of sizes (i.e., 10-6 – 10-1 m) are transported over various distances (i.e., 100 - 104 m) downstream in rivers.  We examined the effects of propagule size on downstream dispersal by releasing biodegradable microbeads (density ~ 1200 kg m-3) of three size classes (~150, 250, 350 µm) at the Speed River, Guelph, ON.  Hitting distance estimates and longitudinal dispersion coefficients declined with particle size and were significantly different between 150 and 350 µm microbeads. The magnitude of these differences was relatively small (~ 5 m) because of the slow velocity (9.5 ± 0.01 cm s-1) and low turbulence (shear velocity = 1.9 ± 0.13 cm s-1) in the river.  We examined the dispersion of larval and juvenile unionid mussels (size range = 56 – 415 µm, 247.54 ± 60.38 [mean ± SD] µm, N = 174) across a broader range of flow conditions by applying laminar and turbulent flow models in three river r..., , # Size matters: Effects of propagule size on dispersal in rivers

Dataset DOI: [10.5061/dryad.5tb2rbpgj](10.5061/dryad.5tb2rbpgj)

## Description of the data and file structure

Particle release trials were undertaken at the Speed River reach on 29 September and 6, 13, and 24 October 2022. Alginate microbeads of three size classes (150, 250, and 350 µm) and types (calcium carbonate-, mica-, and riboflavin-loaded) were released into the stream and recaptured in drift nets (2.25 m length) positioned on the river bottom with their opening (0.45 m width × 0.30 m height) on the riverbed 2, 6, 10, 18, and 34-m downstream of the mid-stream release point.

Microbead capture data were used to calculate hitting distances and dispersion coefficients based on a 1D and 3D advection dispersion model. Parameters provided in the Data-from-Farrow-et-al-SizeMatters.xlsx file correspond to the raw microbead capture data, as well as the derived hitting distances and dispersion coefficients.

All data neede...,