Rivers Intercalibration Phase 2 Key Cross-GIG activities  Refining Reference Conditions  Intercalibrating Large River Ecological Status  Initial scoping meeting Lyon May 2008 Roger Owen Jean-Gabriel Wasson John Murray-Bligh

Reference conditions We need to:  Stabilise the concepts  Harmonise the criteria (QE, GIGs)  Quantify the thresholds : search for "no effect" thresholds  Produce a common procedure Intercalibration Phase : Rivers

Reference conditions : the present situation  Mix of quantitative criteria and "qualitative" evaluation  Mix of:  Driving forces (land cover),  Pressures (dams, effluents)  Stressors (chemical parameters)  Is the relationship maintained in different human and natural contexts ?  Reference Thresholds based on expert judgement  What underlying concepts ? Data ?  Same criteria for all QE ? all types ? Intercalibration Phase : Rivers

Pressure - response relationship The relationship between the driving forces and the biological response is dependent upon the natural and human context Driving forces (Agricultural land cover) Intercalibration Phase : Rivers

FRANCE Intercalibration Phase : Rivers

NORWAY Intercalibration Phase : Rivers

Pressures - responses relationships In this case, a very low biological impact can be observed with a medium level of pressures. Intercalibration Phase : Rivers

Consequences for reference criteria (1)  The relationship between agricultural land cover and biological impact is highly dependent of the structure of the landscape  The relationship is poorly predictive, and cannot be easily extrapolated  Can be used as a first "filter" to select "candidate" REF sites  The relationship with artificial/urban land cover is much more reliable (REBECCA results).  Can be a valid reference criterion Intercalibration Phase : Rivers

Consequences for reference criteria (2)  A very low level of pressures corresponds always to a very low biological impact : valid reference criteria.  The reverse is not always true : a very low biological impact can be encountered also with a medium level of pressures  We should not reject all the sites with a low to medium level of pressures  The validation must be done at the "stressors" level (i.e. abiotic parameters)  This supports the GIG's practical approach based on "reference" and "rejection" threshold  This could apply also to the Urban land- cover indicator Intercalibration Phase : Rivers

Consequences for reference criteria (3)  The relationships between the "stressors" (i.e. abiotic parameters) and the biology is NOT dependent upon the human context.  Can we find the threshold corresponding to the beginning of the biological impact : "no-impact threshold“?  But it can vary according to the natural typology. Intercalibration Phase : Rivers

No-impact threshold : myth or reality ? ? What happens here ? Intercalibration Phase : Rivers

No-impact threshold : is there a conceptual model ? About 100 experts.. Allan, Barbour, Cormier, Gerritsen, Hawkins, Hughues, Karr, Larsen, Mc Cormick, Mc Intyre, Rankin, Wang, Yoder… About 100 experts.. Allan, Barbour, Cormier, Gerritsen, Hawkins, Hughues, Karr, Larsen, Mc Cormick, Mc Intyre, Rankin, Wang, Yoder… Intercalibration Phase : Rivers

Biological Condition Increasing Effect of Disturbance [Stressor gradient] LowHigh 1 Native or natural condition 2 Minimal loss of species; some density changes may occur 3 Some replacement of sensitive-rare species; functions fully maintained 4 Some sensitive species maintained; altered distributions; functions largely maintained 5 6 Tolerant species show increasing dominance; sensitive species are rare; functions altered Severe alteration of structure and function Natural Degraded Intercalibration Phase : Rivers

No impact threshold ICMi vs BOD5 All CB types, France Intercalibration Phase : Rivers

Large rivers - Main issues  Deep rivers in scope (non-wadeable)?  Reference values  Almost no large rivers exist in reference condition (>5000 Km 2 ?)  IC typology limited to rivers <10,000 Km 2 and reference values probably not applicable  Sampling methods  Shallow water sampling methods are inappropriate for deep waters (non- wading depth)  Survey/sampling costs could be high Intercalibration Phase : Rivers

Defining reference values  Consider heavily modified and natural rivers  Check reference screening criteria for large rivers  Investigate alternative approaches for defining reference values/EQRs:  Option: Define the G/M boundary based on physico-chemistry and hydromorphology then biological community Intercalibration Phase : Rivers

Large Rivers Typology  Can we define realistic reference values for EQRs (new typology?)  IC Phase 1: Some MS included deep rivers in intercalibration of RC-5 (large lowland rivers on mixed geology, km 2 ).  Are reference values for shallow water samples appropriate for deep water methods for any BQE? Intercalibration Phase : Rivers

Loss of sinuosity (from historical reference) Coût écologique Sinuosité H/G Boundary Reference From Wasson et al Intercalibration Phase : Rivers

Sampling  Sampling large rivers can be expensive  Consider use of other information to supplement biological data  e.g. measure of lateral freedom space in river types that should have multiple channels Intercalibration Phase : Rivers

Sampling  Investigate sampling methods for deep and large rivers  Identify the biological communities that best reflect the ecological quality of large rivers  Fish (already done in Fish IC?)  Invertebrates  Phytobenthos & diatoms  Others: (eg.Riparian vegetation?) Intercalibration Phase : Rivers

Proposed working strategy  River Steering Group provides a unified approach across all GIGs and biological quality elements (also communicate with lakes GIGs)  Intercalibration of large rivers will be undertaken by existing BQE groups of experts working across GIGs  First step are 2 papers with outline proposals (Nov 08); also a questionnaire to collect information about existing data and methods for all BQEs from all river GIGs – (ready now)  All river GIG meeting to agree detailed work programme Spring 2009