Typology for fully saline waters 

Transitional waters Transitional waters are bodies of surface water in the vicinity of river mouths which are partly saline in character as a result of their proximity to coastal waters but which are substantially influenced by freshwater flows.

Transitional versus coastal Same salinity descriptors <0.5 freshwater 0.5 - <5 oligohaline 5-18 mesohaline 18-30 polyhaline 30-40 euhaline Transitional - tidal range (micro, meso, macro) Coastal - depth (shallow, intermediate, deep)

Transitional and Coastal Waters Types - not categories that are important Are categories a red herring? Significance of transitional waters using fish as a biological quality element

Transitional Waters - for discussion Could be defined using politics (existing legislation) chemistry (salinity) biology geomorphology modelling For WFD, ecologically sound approach should be used

Possible approach….. UK&ROI 1st proviso - our transitional waters are estuaries UWWTD Definition An estuary is the transitional area at the mouth of a river between fresh waters and coastal waters Defined using biologically relevant chemical (salinity) parameters salinity 30 Or, where biologically appropriate, geomorphology

Salinity criteria Stenohaline - >30 salinity Brackish / estuarine spp - 5-18 salinity 18-30 salinity - excludes both groups Draw lines of where the salinity 30 isohaline meets the shoreline and the seabed at high and low water. Problems benthic / pelagic stratification

Dry year Wet year Extent of freshwater influence

Geomorphological Use geomorphological features where ecologically appropriate Or a combination of salinity and geomorphology

Modelling based approach…..

Or if all else fails, use real salinity data! Catchment Area = A m2 e.g. A~10 km2 Rainfall F metre/year = F/700 m/tide e.g. F~1 m/y Ignore smaller catchment areas than 10 km2 B Affected area B m2 B~??? Tidal range R m e.g. R~2m salinity depression ~ 35 A.F/B.R If we take “substantial” as: e.g. 1 to 5 Answer: B ~ 0.1 to 1 km2 Or if all else fails, use real salinity data!

Question Is guidance required on defining transitional from coastal water? Is this a national issue?

Summary

Summary

Summary

Summary

Objectives To establish a common framework for typology of transitional and coastal waters across the North East Atlantic Ecoregion Complex (Annex XI) Atlantic Ocean Norwegian Sea Barents Sea North Sea

Observations Think European MSs only consider factors relevant to them e.g. Germany only consider 1 ‘exposure’, 1 depth etc because that is all they have 10 - 15 for each Member State Are these the same? No Think European

Europe wide typology framework Need to decide on key factors Think European Need to use the factors in the same way Can we do this?