DOI: 10.5061/dryad.5tb2rbpgj
title: Size matters: Effects of propagule size on dispersal in rivers

description: 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 reaches of increasing velocity and turbulence.  Model
 results indicated that the dispersal of smaller larvae increased
 disproportionately with increasing water column turbulence.
  Given that the peak in the size frequency distribution of larvae
 and juveniles corresponded to Rouse numbers (ratio of gravitational
 settling to water column turbulence) P &lt; 1, we suggest a trade-off
 in propagule size in the taxon, whereby the increased dispersal of smaller
 juveniles may come at the cost of reduced settlement success in turbulent
 environments.
description: # 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 needed to
 calculate the derived parameters (e.g., microbead settling velocity,
 depth, shear velocity) following the procedures described in the original
 article are also included. Variables and units are provided in column
 headers and the metadata provided below. Missing data (NA) are indicated
 for trials that were removed because of failure to meet the criteria for
 analysis (See section 2.3 in the original article). All missing data
 represented as NA. ### Worksheet/Tab 1: Farrow-et-al-SizeMatters-Data |
 **Column name** | **Description** | **Units** | **Data format** |
 **Missing data code** | | -------------------------------- |
 ----------------------------------------------------------------------------------------------------------------- | --------------- | --------------- | --------------------- | | Date | The date of the particle release trial, provided in the format (year-month-day). | - | Category | - | | Distance (m) | The distance downstream of the release point. | m | Number | - | | Count | The number of microbeads captured in the drift net. | - | Number | NA | | PercentCapture | The number of microbeads captured in the drift net, converted into a percentage of the total number released. | - | Number | NA | | Count per m^2 | The number of microbeads captured in the drift net, divided by the cross-sectional area of the drift net opening. | m^-2 | Number | NA | | Size (µm) | The size class of the captured microbeads. | µm | Number | - | | w\_s (m/s) | The microbead settling velocity. | m/s | Number | - | | z\_r (m) | The height above the riverbed that microbeads were released from. | m | Number | - | | Type | The type of microbead released. | - | Category | - | | Depth (m) | The depth of the river at the location. | m | Number | - | | TKE (m^2/s^2) | The turbulent kinetic energy measured at the location. | m^2/s^2 | Number | - | | u\*est (m/s) | The shear velocity, estimated from the turbulent kinetic energy measured at the location. | m/s | Number | - | | U (m/s) | The velocity at the location. | m/s | Number | - | | 24h-Q (m^3/s) | The 24-h discharge measured at determined at the Speed River monitoring station. | m^3/s | Number | - | | T (s) | The time estimated for microbeads to pass the drift net. | s | Number | - | | Microbead Flux (particles/m^2/s) | The microbead flux at a drift net. | particles/m^2/s | Number | NA | ### Worksheet/Tab 2: Longitudinal dispersion_3D_for | **Column name** | **Description** | **Units** | **Data format** | **Missing data code** | | --------------- | ------------------------------------------------------------------------------------------ | --------- | --------------- | --------------------- | | River | The name of the river that microbeads were released in. | - | Category | - | | Date | The date of the particle release trial, provided in the format (year-month-day). | - | Category | - | | Size (µm) | The size class of the captured microbeads. | µm | Number | - | | Type | The type of microbead released. | - | Category | - | | Dx (m^2/s) | The longitudinal dispersion coefficient determined from the 3D advection dispersion model. | m^2/s | Number | - | ### Worksheet/Tab 3: Longitudinal dispersion_1D_for | **Column name** | **Description** | **Units** | **Data format** | **Missing data code** | | --------------- | ------------------------------------------------------------------------------------------ | --------- | --------------- | --------------------- | | River | The name of the river that microbeads were released in. | - | Category | - | | Date | The date of the particle release trial, provided in the format (year-month-day). | - | Category | | | Size (µm) | The size class of the captured microbeads. | µm | Number | - | | Type | The type of microbead released. | - | Category | - | | Dx (m^2/s) | The longitudinal dispersion coefficient determined from the 1D advection dispersion model. | m^2/s | Number | - | ### Worksheet/Tab 4: HittingDistancePreds-size corre | **Column name** | **Description** | **Units** | **Data format** | **Missing data code** | | ------------------------------------------------ | ------------------------------------------------------------------------------------------ | --------- | --------------- | --------------------- | | Type | The type of microbead. | - | Category | - | | Size (µm) | The average size of the microbead. | µm | Number | - | | Size/Sizemax | The ratio of microbead size to the largest microbead size. | - | Number | - | | Density (kg/m^3) | The calculated density of the microbead. | kg/m^3 | Number | - | | w\_s corrected (m/s) | The size-corrected settling velocity. | m/s | Number | - | | Laminar model\_hitting distance\_corrected (m) | The predicted hitting distance based on the laminar model, corrected for microbead size. | m | Number | - | | Turbulent model\_hitting distance\_corrected (m) | The predicted hitting distance based on the turbulent model, corrected for microbead size. | m | Number | - | | Empirical\_hitting distance (m) | The hitting distance derived from the empirical particle capture data. | m | Number | - | | SEx\_empirical (m) | The standard error for the empirical hitting distance. | m | Number | - | | Resid\_laminar (m) | The residual for the laminar model prediction. | m | Number | - | | Resid\_turb (m) | The residual for the turbulent model prediction. | m | Number | - | | resid^2\_lam (m^2) | The squared residual for the laminar model. | m^2 | Number | - | | resid^2\_turb (m^2) | The squared residual for the turbulent model. | m^2 | Number | - | | RMSE\_lam (m) | The root mean square error for the laminar model. | m | Number | - | | RMSE\_turb (m) | The root mean square error for the turbulent model. | m | Number | - |