Biomass Line description
Use the biomass line to monitor the current biomass in the echogram. This function writes an extra thick and brightly coloured curve on the echogram.
How to open
To activate the biomass line, click in the echogram view to make it active.
Select Echogram on the Active menu. On the left side of the Echogram dialog box, select Lines to open the page. Select Biomass Line.
Description
A biomass line can be added to your echogram to retrieve additional information. This function writes an extra thick and brightly coloured curve on the echogram. The biomass line shows you the integrated biomass for the pings within the selected calculation interval. This is a visual enhancement. The choice you make has no effect on the overall performance of the EK80 system.
Note
If you have other echo sounders or sonars running asynchronous with the EK80 system, these other systems may cause interference. The EK80 system may detect and measure the transmit pulses from other hydroacoustic systems, and these pulses have an effect on the
biomass calculations. To avoid all interference, a full synchronization of the various acoustic instruments is required. If your own vessel produces excessive noise this will also be taken into the biomass calculations and give you inaccurate
data.
The EK80 system records all the targets from the smallest plankton to the largest whale. The biomass value is an indicator to how
much fish you currently have in the beam. Every single fish will emit an echo, and the sum of all these registered echoes
are presented as a number. Smaller organisms such as plankton will also emit echoes, but these are so weak that they will
hardly influence on the total biomass.
The biomass value provides you with information about the fish abundance, and as such it may help you to decide if it pays
off to start fishing. However, you must consider if the biomass value is a result of large amounts of plankton or bait, or
if you have "real fish" below the keel. The biomass value is relative, and after some use your experience will be a valuable
factor when the decision is made.
Change the scale to fit the vertical space available on the echogram. To add the biomass line to the echogram and change the scale, open the Lines page in the Echogram dialog box. The Echogram dialog box is located on the Active menu.
Tip
You can also measure the biomass in the Biomass information pane. The Biomass information pane displays an index of the biomass in the current view. The biomass index is the sA value, or Nautical area scattering coefficient (NASC), measured with unit m2/nmi2.
Changes made in the Calculation Interval dialog box have effect on the line.