Literature Swim Speeds Tab

In the Literature Swim Speeds tab, you select swim capabilities from a provided set of swim speed information obtained from available literature. Select the desired swim speed from the compiled database by clicking the Select Data button, which will bring up the Literature Swim Speeds Window.

Fish Length:

Enter the Total Length of the fish, if only fork length is available, you may use the Fish Length Conversion Table to estimate total length.  The difference between fork and total length is likely only significant for smaller fishes.  

Warnings:

If any of the user-defined variables are outside the range of conditions that define the Literature values, a red Warnings link will be displayed.  Clicking on the link will display the warnings in a new window. Warnings are assigned when entering a fish length or time to exhaustion that falls outside of the lengths or swim times associated with the selected swim speed test.  A warning is also given if you enter a minimum water depth less than the reported Fish Body Depth. The warnings are only applicable to the Literature Swim Speeds tab. They are informational and do not impede calculations.

Select Data:

Pressing the Select Data button will open the Literature Swim Speeds Window. From the database you can select Prolonged and Burst Swim speeds for a variety of species. Selecting a line in the table will display the reference in the information box. The complete references can be found in References. The complete data set can be viewed and copied by pressing the View Swim Speed Data button on the lower left. The entire data table can also be downloaded in a spreadsheet format from the help files in the Swim Speed Table section.

Prolonged / Use Both / Burst:

Select the Swim Mode to be used in the model run.  Swimming performance is classified into three major categories:  sustained, prolonged and burst. FishXing uses only prolonged and burst. If either Burst or Prolonged are selected, the swimming speeds associated with the category will be exclusively used throughout the culvert.  If Use Both is selected FishXing allows the fish to switch between prolonged and burst speeds as needed.  The fish are able to maintain burst or prolonged speeds for the duration of time entered in the Time to Exhaustion field.

Choosing Use Both can be useful when water velocities in the barrel of the culvert are low enough for passage in the prolonged swim mode, but the velocities within the inlet and outlet zones of the culvert are fast enough to require swimming in the burst mode.

Prolonged Speed:

Prolonged swim speeds usually can be maintained by the fish for 20 seconds to 200 minutes before ending in fatigue.  Most fish passage velocity criteria are based on the prolonged swim speed of the target fish.

Burst Speed:

Burst speeds are the highest speeds attainable by the fish and can be maintained for only short periods of time, usually less than 20 seconds.  Fish may need to use burst speeds to swim through areas of high velocities in the culvert.

Time to Exhaustion:

Time to Exhaustion is the period of time that a fish can maintain the swim speed selected before becoming exhausted.  Times typically range between 20 seconds to 200 minutes for prolonged swimming speeds and 1 to 20 seconds for burst swimming speeds.

Notes and References:

The green notes area displays information about the literature swim speed selected from the database, including scientific and common species names and test conditions used to derive the swim speed.

Min Depth:

The minimum water depth is the depth of flow within the crossing required for successful fish passage.  A depth barrier is reported if the calculated water depth is below the specified Min Depth. The Min Depth should be sufficient to fully submerge the species being modeled because fish that are not fully submerged cannot obtain optimal swimming performance.  If the Min Depth is less than the Fish Body Depth reported in the Notes (green text box), a warning will be issued.  See Water Depth for Swimming for a discussion on the limitations of swim speed equations when a fish is not fully submerged.

Outlet Criteria:

From the dropdown select the method you wish to use for analyzing fish passage conditions at the culvert outlet. The two options are:

Max Leap Speed – Enter the maximum speed the fish can leap out of the water when attempting to leap into the culvert outlet.  This speed is often at the upper end of the fish’s burst swimming ability.  Leaping calculations only occur when the fish is unable to swim into the culvert.  See Leaping Calculations and Entering the Culvert: Outlet Leap or Swim or an explanation of how FishXing determines when the fish can swim into a culvert rather than leap.

Max Outlet Drop – Enter the maximum allowable drop in water surface at the outlet.  FishXing will identify a drop barrier when the outlet drop is greater than the specified Max Outlet Drop.  The outlet drop is measured between the water surface in the outlet and the tailwater surface.  Unlike the leaping calculations, the outlet drop criteria apply even when the tailwater elevation is above the culvert bottom.  See Outlet Drop Criteria for a discussion on how and when the drop is calculated.