1. Working Group on Reference Conditions
ECOSTAT Report October 2010
Roger Owen & Isabel Pardo

2. Tasks of Reference Condition WG
1. Review of the consistency in the application of Reference criteria
2. Reference sites compliance with CB thresholds and validation of CB thresholds
3. Refine reference concepts for possible future application

3. 1. Review of the consistency in the application of Reference criteria

4. Consistency of Application by MS of GIG Criteria
MSs responses to reference screening questionnaire: How the GIG criteria were applied in practice
High percentage of missing information
Not consistent MS and GIGs application

5. 2. Reference sites compliance with CB thresholds

6. Reference sites compliance with CB thresholds
Compliance of MS of CB reference/rejection thresholds
Only 13 MS of 27 MS (all GIGs) submitted pressure data for reference sites used in IC phase I
IN general low compliance by MS
Few MS had mean chemical values for reference sites; and some values are over the thresholds

7. 2. Reference sites compliance with CB thresholds
Variation in the number of reference sites

8. Examples for land use: number of sites
Artificial land use: Rejection threshold= 0.8%
Artificial land use
Non compliance:
9 of 12MS (75%)
% of non compliant sites:
from 0 to 39% across MSs
UK and EE, high percentage of missing land use data

9. Examples for land use: number of sites
Intensive agriculture land use: Rejection threshold= 50%
Intensive agriculture
Non compliance:
2 of 12MS (17%)
% of non compliant sites:
from 0 to 12% across MSs
EE, high percentage of missing land use data

10. 2. Reference sites compliance with CB thresholds
Variation in the number of reference sites
Variation in the mean MS_EQR value

11. Examples for land use: MS_EQR value
Strict application of artificial and intensive agriculture rejection thresholds.
Mean MS_EQR value affected less than number of sites
Maximum difference in mean EQR between original and compliant sites is 9.2% [LT] (mean difference = 2.0% ± 2.9[SD])
Maximum difference in mean EQR between non-compliant and compliant sites is 58.8 % [SE, positive] and 16.2 [SI, negative, one site] (mean difference = 10.9% ± [SD])
Note: this comparison is biased due to EQRs being corrected by national median reference values including compliant and non compliant reference sites. An absolute comparison should use ICM values.

12. 2. Validation of CB thresholds: Reference sites from 12 MSs

13. Non validated threshold
Validation of CB-thresholds: EQR values
WFD CIS Guidance Document No. 14: Guidance on the intercalibration process , “The level of very low pressure should be defined on the basis of statistical relationships demonstrating that the level of pressure accepted to select a reference site is unlikely to have a significant impact on the biological quality element”.
References
No references
Validated Threshold
References
No references
Non validated threshold

14. Non validated threshold
Thresholds compliant Reference sites: EQR values
Data provided by 12 MSs, from 327 COMPLIANT REFERENCE samples
Reference
threshold
p < 0.05
p < 0.05
So using this data: artificial threshold is OK but intensive agric is not?
Validated Threshold
Non validated threshold

15. Thresholds compliant Reference sites: EQR values
Data provided by 12 MSs, from 327 COMPLIANT REFERENCE samples
Rej threshold
Rej threshold
Rej threshold
RC1,RC2
RC4,RC5,RC6
p < 0.05
RC3
RC1
RC4
RC5
RC6
RC2
RC3
RC2,RC3
RC1,RC4,
RC5,RC6
So where significant trend then likely we have a detectable biological impact even amongst this population of compliant reference sites? Should we show the actual threshold values to demonstrate that better?

16. Thresholds compliant Reference sites: EQR values
Results from the validation of CB thresholds: Strict application to EU data
Preliminary analyses (carried out with limited data set: 12 MSs) evidence that the thresholds set for “Intensive agriculture” and “Mean dissolved oxygen” yield in a significant relationship within the references, so thresholds may not represent absence of biological impact and the threshold needs refinement
The rest of the thresholds did not show a significant relationship. Notwithstanding, further analyses and more data are needed to draw robust conclusions
Note: these analyses have been conducted on MS´s EQRs.

17. 2. Validation of CB Thresholds by MS data:
Austria, Sweden, Belgium-RW, Spain and Portugal
Reference and non reference sites

18. Validation of CB Thresholds by MS: EQR values
Validation of CB thresholds: Example with CB SPAIN data
Number of samples: 914 (CB GIG), number of reference samples = 123
References with artificial
land-use<0.8%
References with artificial
land-use<0.4%
What does “no-null” values mean?
The number of reference sites with land-use values below the thresholds is very small, precluding further statistical analysis. However, it seems that there is a negative relationship even below the threshold.
SPAIN

19. Validation of CB Thresholds by MS: EQR values
Validation of CB thresholds: Example with CB SPAIN data
Non-references with artificial
land-use>0.4%
Non-references with artificial
land-use>0.8%
So there is a sig trend above these thresholds - what does this tell us about our threshold values? Omit slide?
R2 = 0.070; p < 0.001; n = 321
R2 = 0.070; p < 0.001; n = 249
Significant trends >0.4 and > 0.8 %
SPAIN

20. Validation of CB Thresholds by MS: EQR values
Validation of CB thresholds: Example done with CB SPAIN data
References with
intensive agric < 20%
References with
intensive agric < 50%
R2 = 0.005; p = 0.470; n = 107
The threshold might be adequate
R2 = 0.071; p = 0.004; n = 113
The threshold seems to be inadequate
Significant trend
No significant trend
SPAIN

21. Validation of CB Thresholds by MS: EQR values
Validation of CB thresholds: Example done with CB SPAIN data
Non- references with
intensive agric>20%
Non- references with
intensive agric>50%
What does this tell us about our threshold values? Omit slide?
R2 = 0.074; p = 0.002; n = 130
R2 = 0.287; p = 0.015; n = 20
Significant trend
Significant trend
SPAIN

22. Validation of CB Thresholds by MS: EQR values
Validation of CB thresholds: significant relationships in the 5 MS that provided data on references and non references
Reference sites
Non-reference sites
Artificial
Intensive agric AT SE
BE-RW
>0.8% ES
<50%
>0.4%
>20%
>50% PT
Significant biological impact in the reference biota below the intensive agriculture rejection thresolds
No significant biological impact in the NON Reference biota above both reference and rejection thresholds

23. 3. Refine reference concepts for possible future application

24. Refine reference concepts
Identification of new fields where further conceptual development is needed with new accompanying methodologies for setting reference conditions (Biological Condition Gradient)
Further work on biological responses to pressures and the establishment of relevant quantified and standardised thresholds for reference and other status classes

25. Issues
Phase 1: we showed inconsistent application of GIG criteria and problems of compliance with the GIG thresholds
We cannot provide a set of recommended revised thresholds because many MS have not sent data – as mandated by ECOSTAT
The river invertebrates GIGs (CB and ALP) recommend that we do not revise the Phase 1 agreed boundaries
ECOSTAT needs to decide how to proceed for any revision during this Phase of IC to revise reference conditions for the 2nd River Basin Plan

26. Next steps
To finish our tasks in the RC WG, (Refine Reference Condition concepts and test biological responses in the absence of pressures) we need more data from MSs, on ref and non ref sites, and on various relevant pressures:
There are datasets provided by MSs to the intercalibration phase II (i.e. Mediterranean and Eastern GIGs), that can be very useful
Request to WISER to see if it is possible to access their rivers databases for REF COND analyses
We need to work across European gradients because pressures relevance may vary along environmental gradients and countries
We need to work on comparable metrics (Common metrics) across countries

27. Way Forward? Recommendations:
We can continue the RC work on existing and newly requested datasets, to develop methodologies that can illustrate the work ahead for the refinement and the establishment of relevant quantified and standardised thresholds for reference and other status classes.
This can provide results for June 2011 if we work in parallel with GIGs
As an alternative, and due to the magnitude of the work involved, we coud propose the launch of a Research project were MSs datasets on reference sites should be involved.
This alternative will not provide results before June 2011 – longer term solution