1. Saltmarsh Intercalibration CW
COASTAL AND TRANSITIONAL WATERS INTERCALIBRATION VALIDATION WORKSHOP
ISPRA 17 nov 2011
E. Van den Bergh (BE), Joao Neto (PT), Jose Juanes (ES), Robert Wilkes (IE)

2. 1. Compliance of methods
DE – EM (WISER ID 130): Saltmarsh in CW and TW
Metrics:
Abundance: SM extent compared to historical reference
Taxonomic composition: Relative representation of SMzones compared to reference
Combination rule:Mean
NL – TSM (WISER ID 259, to be adapted): Saltmarsh in CW and TW
Combination rule: One out All out
UK – SM (under construction): Saltmarsh in CW and TW
Abundance:
Saltmarsh extent compared to historical reference
Saltmarsh extent compared to intertidal
Taxonomic composition:
Number of zones compared to maximum
Maximum zone area
Number of species/zone compared to reference
Combination rule: Weighted mean

3. 1. Compliance of methods Abundance = extent
Calculation rule for abundance differs
Disturbance sensitive taxa = vegetation zones
Definition of zones differs
Calculation rule for zonation differs
No species information for NL-DE
REFCOND: historical interpretation and expert judgement, no near natural sites
UK adds species representation for taxonomic composition
All methods comply

4. 2. Feasability
Biotypes:subtypological variants based on physical and chemical xtics

5. 3 Data DE – EM 5 NWB 5 EQR NL – TSM 1 NWB 1 HMWB 2 years each 4 EQR
UK – SM
9 HMWB, 5 NWB
SM extent + SM ZONES
5 HMWB 16 NWB SM extent only
14 EQR
21 EQR
abundance only
TOTAL
11 NWB + 10HMWB
23 Complete EQR

6. 4 Pressures Method Pressure Remarks DE – EM Physical disturbance
hydro-morphological changes
habitat loss
Not tested
NL - TSM
UK - SM
Tested

7. Common approach: Pressure Table for Saltmarsh(CW)
4 Pressures
Common approach: Pressure Table for Saltmarsh(CW)
Method
Pressure category
Pressure indicators
Remarks
DE – EM
NL – TSM
UK – SM
Hydromorphological
Land Claim
Shoreline re-enforcement
Hydromorphological risk assessment
Resources use change
Dredging area & volume
Disposal area & volume Marina development
Tourism & recreation

8. 4 Pressure Indicators Hydromorpological pressure
Landclaim % intertidal
Shoreline % reinforcement
Dredge disposal area % subtidal
Summed up as Total HMP
Maximum value as Maximum HMP
For UK only tested on surveillance sites with info on SM extent AND zonation (5wb)

9. 4 Pressure EQR response

10. 5 Assessment concept Method Assessment concept DE – EM NL – TSM
Extent of saltmarsh compared to historical reference
relative extent of vegetation zones
Vegetation mapping with aerial photos and ground truthing (GPS)
UK-SM
Same elements + species presence
OPTION 2
Similar concepts
Different measurements and metrics
DATA
Quality Classes covered across GIG, not at MS level

11. 6 Common Metrics
CM 1: SM extent as proportion of reference, truncated at 1
CM 2: H’ of 4 predefined vegetation zones: pioneer, low, mid, high marsh, normalised to values between 0 and 1
CM 3: (CM 1 + CM 2)/2

12. 6 Common Metrics/ EQR response
Selection of CM3

13. 6 Common Metrics Pressure response
40 Max pressure
60 Total pressure
G/H
Reasonable response to total and max hydromorphological pressure

14. 7 REFCOND-BENCHMARK No unimpacted reference sites in DB
Defined Ref cond
SM extent > 100% Ref
H’ >3,75
Defined G-H boundary:
SM extent is > 80% Ref
Ref and H’>3,25 (nearly all zones present, no real dominance of one zone)
Total pressure < 60%, max pressure < 40%
Not sufficient alternative benchmark sites in dataset: one dummy added to DB for each MS: EQR=1; CM3=1

16. 8 Boundary setting and adjustment
OPT 2 DIV
UK-SM
NL-TSM
DE-EM
Max
1,000
H/G
0,779
0,820
0,818
G/M
0,616
0,758
M/P
0,400
P/B
0,200

17. Common metric selection: the common metric combining a diversity and abundance metric was concluded not to be appropriate, since the abundance metric was taking into account different Member State views on the reference condition.
9 workshop conclusions
CM3 combining diversity and abundance takes MS views on RC
Take H’ instead; relationship with pressures still to be illustrated.
Continuous benchmarking instead of dummy

18. Later remarks (W. Bonne)
H’ no good response to pressure
Different appreciation between MS
related to a national view or to existing differences in nature?

20. Way forward?
Continue with a common metric by using the way of derivation how one Member State did it and apply this to all: already done
The outcome of the calculation sheets probably reflects the good relation of a national view with the national view,
IS SURFACE ACCEPTABLE AS MEASURE FOR ABUNDANCE?