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)

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 Compliance of methods DE – EM (WISER ID 130): Saltmarsh in CW and TW Metrics: Abundance: SM extent compared to historical reference Taxonomic composition: Relative representation of SMzones compared to reference Combination rule:Mean NL – TSM (WISER ID 259, to be adapted): Saltmarsh in CW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rule: One out All out UK – SM (under construction): Saltmarsh in CW and TW Abundance: Saltmarsh extent compared to historical reference Saltmarsh extent compared to intertidal Taxonomic composition: Number of zones compared to maximum Maximum zone area Number of species/zone compared to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

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

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

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

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

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

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)

4 Pressure EQR response

5 Assessment concept Method Assessment concept DE – EM NL – TSM Extent of saltmarsh compared to historical reference relative extent of vegetation zones Vegetation mapping with aerial photos and ground truthing (GPS) UK-SM Same elements + species presence OPTION 2 Similar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

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

6 Common Metrics/ EQR response Selection of CM3

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

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

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

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

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?

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?