SACFOR abundance scale used for both littoral and sublittoral taxa from 1990 onwards

 
NB. Read notes below prior to use of scale
  Growth form  Size of individuals/colonies  
% cover
Crust/meadow
  Massive/Turf  <1cm 1-3 cm 3-15 cm >15 cm Density 
>80%
S
 
S
     
>1/0.001 m2
(1x1 cm)
>10,000 / m2
40-79%
A
S
A
S
   
1-9/0.001 m2
1000-9999 / m2
20-39%
C
A
C
A
S
 
1-9 / 0.01 m2
(10 x 10 cm)
100-999 / m2
10-19%
F
C
F
C
A
S
1-9 / 0.1 m2
10-99 / m2
5-9%
O
F
O
F
C
A
1-9 / m2
 
1-5% or density
R
O
R
O
F
C
1-9 / 10m2
(3.16 x 3.16 m)
 
<1% or density
 
R
 
R
O
F
1-9 / 100 m2
(10 x 10 m)
 
         
R
O
1-9 / 1000 m2
(31.6 x 31.6 m)
 
           
R
<1/1000 m2
 
 
Use of the MNCR SACFOR abundance scales
The MNCR cover/density scales adopted from 1990 provide a unified system for recording the abundance of marine benthic flora and fauna in biological surveys. The following notes should be read before their use:
  1. Whenever an attached species covers the substratum and percentage cover can be estimated, that scale should be used in preference to the density scale.
  2. Use the massive/turf percentage cover scale for all species, excepting those given under crust/meadow.
  3. Where two or more layers exist, for instance foliose algae overgrowing crustose algae, total percentage cover can be over 100% and abundance grade will reflect this.
  4. Percentage cover of littoral species, particularly the fucoid algae, must be estimated when the tide is out.
  5. Use quadrats as reference frames for counting, particularly when density is borderline between two of the scale.
  6. Some extrapolation of the scales may be necessary to estimate abundance for restricted habitats such as rockpools.
  7. The species (as listed above) take precedence over their actual size in deciding which scale to use.
  8. When species (such as those associated with algae, hydroid and bryozoan turf or on rocks and shells) are incidentally collected (i.e. collected with other species that were superficially collected for identification) and no meaningful abundance can be assigned to them, they should be noted as present (P).