1. Intercalibration : a “WFD compliant” boundary comparing procedure
WG 2A ECOSTAT meeting - Ispra, October 7-8th, 2004
Mediterranean, Alpine, Central - Baltic
River GIGs
Scientific input from
Intercalibration : a “WFD compliant” boundary comparing procedure
Jean-Gabriel WASSON
UR BEA/LHQ, Lyon, France 1

2. IC problems for Rivers Ancient, different methods
sampling, laboratory and concepts
Extensive monitoring networks in all MS
Various pre-existing classifications (MS and / or QE)
(preliminary) Ecological Status boundaries in most MS
Not possible to construct a common boundary setting protocol on such different tools

3. Classification methods (1)
Pre-existing
Index and related classifications
Variable number, definition, extension of classes
valid for all types ? Reference ?

4. Classification methods (2)
REF value = Median
sites
EQR 1
maximum
alteration : 0
« Old index » transformed in EQR
Boundaries values adapted to type Reference
independent
from pressures
REFCOND
Guidance

5. Classification methods (3)
REF value =
maximum observed ?
minimum value =
minimum observed ?
EQR 1
Multivariate analysis &
classification
e.g. STAR
dependent
from the
dataset ?

6. Classification methods (4)
Previous classification of sites according to pressures
Sites
Biological metrics are adjusted to discriminate the 3 groups of sites
Index
values
H + G M
L + B
FAME
& French
« indice poisson »
dependent from the pressure classification

7. IC objectives : WFD concepts & normative definitions
To ensure that boundaries (H/G and G/M) correspond to
the same level of ecosystem alteration between MS
We compare the boundaries, not the methods..
Ecosystem alteration is a deviation from Reference Conditions
Necessity to include the Reference Conditions in the IC process
Necessity to evaluate the Ecosystem alteration with metrics consistent with WFD normative definitions 1

8. Comparing MS boundaries
If 3 MS get for G/M boundary : EQR 0.6, 0.7, 0.8
Is it a difference in
Method or
Ecosystem alteration ?
BB 0.7
CC 0.6
AA 0.8
No major difference OK
WFD
compliant
Common
Metrics
0.7
0.6
0.8
Major
differences
=> Harmonization

9. natural (biogeographical) and methodological differences ?
How to normalize
natural (biogeographical) and
methodological differences ?
Include Reference Sites in the dataset
H/G
G/M
Member State AA BB GG
e.g. :
number
of taxa
Ref
Mini
EQR ? ??
Common metric = loss of taxa (in EQR)

10. Comparability of Reference
Methods & Criteria for the selection of reference sites
MS that have defined their RC agreed that the level of exigency was comparable (despite different methods)
How to derive a Reference Value to calculate EQR
The median of the values observed in reference sites is the most logical and robust statistics (generally agreed).

11. How to comply with the Normative Definitions of Ecological status ?
Invertebrates in rivers
good / moderate
Taxonomic composition and abundance
level of diversity
Disturbance sensitive taxa
Moderate status : Major taxonomic groups absent
how much is slight ?

12. WFD compliant metrics... Taxonomic composition & abundance Diversity
Definition
Nb Taxa
Total number of taxa (family level)
EPT Taxa
Number of Ephemera, Plecoptera and Trichoptera families
Diversity index
Shannon-Wiener diversity index,
or Pielou (evenness)
ASPT
Average Score Per taxa (from BMWP table)
GOLD%
1 – (relative abundance of Gastropoda + Oligocheta + Diptera)
log10
Sel ETD
log10 (number of individuals) from selected families of Ephemeroptera, Trichoptera, and Diptera
Taxonomic composition &
abundance
Diversity
Sensitive taxa
Major groups

13. ...responding to a wide range of pressures.

14. Common metrics currently tested for Central / Baltic and Mediterranean GIGs

15. How to compare boundaries ? e.g. IBGN vs ICM - Type R-M1
IBGN protocol samples
quantitative faunistic lists
Reference Sites included
IBGN
ICM
Median of Ref. samples
EQR
IBGN
ICM
Slight deviation from REF =
mean class : 18% maximum : 25%

16. How to compare boundaries ? Type R-C2 - Spain & France
MMI
(Galicia)
R2 : 0.915
R2 : 0.796
France
IBGN

17. If Reference is not available ?
The work is not yet done..
A Pilot can be run with different normalisation procedure ( e.g. Q75th of High class)
RC should be available for the real exercise
Ref sites cannot be found for some types or MS (too much alteration)
Seek for RC in other MS
Derive a common procedure to define RC
Choose another option