Background

The ability to predict fish swim speed and stamina is helpful in the development and design of fish passage, exclusion, and guidance systems. The Swim Distance & Water Velocity tool generates a plot showing swim distance versus water velocity using a model built on 27,030 individual fish found in 132 data sources. For details on the model, dataset and how these calculations are performed, see Katopodis & Gervais (2016). The model calculates the mean swimming performance surrounded by 75% and 95% prediction intervals. These intervals show the expected range of swim performance values. For example, 95% of unsampled fish should fall within the bounds of the 95% prediction interval.

In this manual, a sample question will be answered using this tool.

##Question

A proponent wishes to install a 30 meter culvert. What is the maximum water velocity that 97.5% of 400 mm northern pike can pass through?

##Steps

  1. Go to the Swim Speed & Swim Time tool.
  2. Below “Select Fish by:”, click the “Common name” radio button.
  3. In the “Select species” drop down menu, choose “Northern Pike”.
  4. Drag the “Fish length” slider to 400 mm.
  5. Below “Calculations:”, press the “Water velocity” radio button
  6. Enter “30” in the “Swim distance in meter:” box.

Once these steps are completed, the tool should look like this:

##Solution

This culvert should not exceed a maximum water velocity of 0.35 m/s to allow passage of 97.5% of 400 mm northern pike.

##Calculating swim distance

The tool can also be used to determine swim distance based on water velocity. For example, select the “Swim distance” radio button below “Calculations” and enter 0.35 into the “Water velocity” box. The plot will update and show 97.5% of 400 mm Pike in 0.35 m/s current can swim 30 m.

##Manual calculations

The fish swimming performance models presented in Katopodis & Gervais (2016) are potentially useful but required solving complex equations. The web tool reliably and quickly performs these calculations, reducing the likelihood of an erroneous result. In this section, the simplified equations from the report are displayed for reference.

First, calculate Swim Speed using this formula:

\[U = kt^b \sqrt{gl}\left(\frac{l}{g}\right)^{-b/2}\]

Where:

Once Swim Speed (U) has been calculated, Distance (X) can be calculated using:

\[X = M\left(\frac{ U(1+b)}{\sqrt{gl}} \right) ^a \times l\] Where M and a are coefficients derived from dimensionless speed vs. time regression. M and a are reported in Katopodis & Gervais (2016).

Alternatively, Swim Speed (U) can be converted to Water Velocity (V) in m/s using:

\[ V = U(1+b) \]

##Model limitations

Some fish swimming performance groups had limited data available. This lack of data for certain groups may affect the estimated performance. These limitations are outlined below: