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Biomass information pane description
The Biomass information pane displays an index of the biomass in the in the current
Inspection view. The biomass index is the
coefficient (NASC), measured with unit m
How to open
Before you open an information pane, you must first click in an Inspection view to make
it "active". The information provided will only be valid for the selected view.
To open the Biomass information pane, click in the chosen view to activate it, then select
the
button on the top bar. To close the information pane, select it one more time
Biomass
on the top bar. You can also select
Note
Information panes are only available for Inspection views.
Description
The digit shown in the Biomass information pane is a calculated index.
If more than one target is located in the acoustic beam at the same depth, it is not
usually possible to resolve them separately. This is often the case with schooling
fish or aggregations of zooplankton. In these cases, echo integration is used to
estimate biomass. Echo integration assumes that the total acoustic energy scattered
by a group of targets is the sum of the energy scattered by each individual target.
This assumption holds well in most cases. The total acoustic energy backscattered
by the school or aggregation is integrated together, and this total is divided by the
(previously determined) backscattering coefficient of a single animal, giving an
estimate of the total number.
http://en.wikipedia.org/wiki/Fisheries_acoustics, March 2015
The CS90 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.
442700/A
value, or Nautical area scattering
s
A
2
/nmi
2
.
in the top right corner of the pane.
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