8 Investigating the biomass
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.
Context
The digit shown in the Biomass information pane is a calculated index.
Tip
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. The biomass line shows you the integrated biomass for the pings within the selected calculation interval. 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.
It is possible to convert the biomass index to weight (for example in metric tons). Based on practical use of the EK80 system in different fisheries, you will soon be able to estimate the weight when you know the type of fish and their sizes.
Procedure
| 1 | Click in the view you want to activate. The active view is identified with a thicker border. The information provided will only be valid for the selected view.
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| 2 | On the top bar, select the appropriate information pane to open it. |
| 3 | Click the bottom right corner of the information pane, and drag to requested size. |
| 4 | Select a Transparency setting that fits your requirements. The chosen transparency percentage is used on all open information panes.
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| 5 | Investigate the information provided by the information pane. 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.
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| 6 | Select Close in the top right corner to close the information pane. |