This function calculates abundance as the product of density and stratum area
Quantity(MeanDensityData, StratumAreaData)
The MeanDensityData
data.
The StratumAreaData
data.
An object of StoX data type QuantityData
. The QuantityData
contains both an Abundance and a Biomass column, but only one of these can be populated.
The function merge the MeanDensityData
with the StratumAreaData
by Stratum and calculates the abundance as the product of density (number by square nautical miles) and area (square nautical miles).
For acoustic-trawl estimates the abundance is calculated by Stratum, Layer, Beam, SpeciesCategory and IndividualTotalLength.
In swept-area estimates the abundance is calculated by Stratum, Layer, SpeciesCategory and IndividualTotalLength
For swept-area estimates the density calculated by SweptAreaDensity
can be given as "AreaWeightDensity" (as indicated by the column DensityType
). In this case the Biomass
column and not the Abundance
column is populated in the output QuantityData
from this function. The biomass is given in kilogram in this case, as Density is in kilogram per square nautical mile if DensityType
= "AreaWeightDensity". This is different from the Biomass
column of SuperIndividualsData
, which is in gram, as it is generated from IndividualRoundWeight which is in gram.
SuperIndividuals
for distributing Abundance to individuals.