BioDjinn

Data scenario matrix

Case
SA [m2]
SampledArea
SV [m3]
SampledVolume

RA [m2]
ReferenceArea
RV [m3]
ReferenceVolume

N [-]
Number
A [N/RA]
A [N/RV]
Abundance
PA [0,1]
Presence/Absence
Rep [-]
Replicates
GSA [m2]
Gear.Area
Products
Notes
0a
(+)

+
 

1
(+)
ABCD
  • Situation: 1 sample, 1 replicates * sampled_ area
  • Rules R1, R2 and R3 apply
  • Formula F1 or F2 may have to be used
0b
(+)

+
 

n
(+)
ABCD
  • Situation: 1 sample, n replicates * sampled_ area (total sum)
  • Rules R1, R2 and R3 apply
  • Formula F1 or F2 may have to be used
  • If necessary, consider F3 for scientific analyses
0c

+
+
+


(+)
ABCD
  • SA can be calculated from RA, N, A: SA=(N*RA)/A
  • Possible GSA will be tested against RA, N, A (only with gear trawl)
  • Rules R5 may apply

  • Formula F4 applies

  • Formula F1 or F2 may have to be used

1a

+

+


+

ABCD
  • Formula F5 must be applied
1b

+

+




A
2


+





C
  • Possible GSA will not be tested anyway
  • GSA is allowed
3
(+)



+

(+) B
  • Rules R1, R2 and R3 apply
  • Formula F1 or F2 may have to be used
4




+


D
  • GSA is allowed
  • RA is allowed

General rules

(R1) SA and/or GSA must be given.
(R2) If SA is given, it takes precedence over GSA.
(R3) If SA is not given, GSA must be calculated (see Formulas F1 and F2).
(R4) If replicates per sample are given, SA or GSA represents the sampled area per replicate.
(R5) If GSA is given, calculated SA (see Formula F4) is tested against GSA to check if SA and GSA are equal. The test is performed for all gears except trawls.

General formulas

(F1) GSA (for grab samples) = grab length * grab width
(F2) GSA (for trawl samples) = trawl gear width * sampling distance; sampling distance = towed speed * towed time or sampling distance is defined by latitude/longitude coordinates of sampling start and end (these formulas are generally valid for all towed gears)
(F3) Total SA/sample = n rep * SA; total GSA/sample = n rep * GSA
(F4) SA = (N*RA)/A
(F5) N = (GSA*A)/RA

Parameters

SA
Sampled Area
defined in sample.sampled_area
SV
Sampled Volume
defined in sample.sampled_vol
RA
Reference Area defined in sample.reference_area
RV
Reference Volume defined in sample.reference_vol
N
Number Count of individuals defined in biota.number

A
Abundance Density of individuals defined in biota.abundance
Calculation of abundance:
A=(N*RA)/SA
or
A=(N*RV)/SV
PA
Presence/Absence Presence/absence of individuals defined in biota.presence_absence
Rep
Replicates
Number of replicates per sample defined in sample.replicates
GSA
Gear Sampled Area
Sampled area calculated from the information in the gear lookup table. There are several ways to calculate the area for different gear categories (see below for more information).

Products

A
Abundance biomass
B
Biodiversity-3 relationship  N.spec - area  (number of species to area)
C
Biodiversity-2 relationship N.spec - N.ind (number of species to number of individuals)
D
Biodiversity-1 N.spec (number of species)

Gear categories

Allowed gear categories: grab, trap, sensor, scrape, video, trawl, rocks, census, remote sensing dive

Discarding A in Scenario 0a/0b

Do not record A at ingest, because it  can be calculated from SA and N.

Types of calculating gear sampled area (GSA)

grab/trap/sensor/scrape/rocks/dive/video/census/remote sensing
trawl

Sampled Area is defined or calculated in one of following ways:

All testing rules

Violation of the following rules leads to the triggering of a warning:

Gear.SamplingUnit is set to 'both'

Violation of the following rules leads to the triggering of an error:

Number

Abundance

Number, abundance or presence/absence

Sampled area and reference area

Area/Volume and Gear.SamplingUnit

Sampled volume and reference volume

Gear pretest

trawl: Sampling distance

Testing the calculation of the gear sampled area

a) Gear sampled area (GSA) and (directly defined) sampled area (SA)

grab/trap/sensor/scrape/rocks/dive/video
trawl

b) Gear sampled area (GSA) with given reference area (RA), number (N), abundance (A)

grab/trap/sensor/scrape/rocks/dive/video and Scenario 0c

c) Gear sampled area (GSA) with given reference area (RA), number (N), replicate (Rep)

Replicates
trap time and sampled area