Monitoring macroinvertebrater in Norwegian rivers?

1. Monitoring macroinvertebrater in Norwegian rivers? Torleif Bækken , NIVA

2. Data in database (NIVA base) relative to ASPT Potential ref. sites, but where and type?

3. Data in database (NIVA base) relative to EPT species

4. The initial intercalibration selection on river types

5. Reference intercalibration data? • Norway with sufficient data on two types: R-N1 and R-N4 • R-N1 and R-N4 (lowland types) 52 sites inkluding 9 reference sites

6. Ongoing monitoring of rivers • Monitoring Norwegian reference rivers: Atna (mountain-boreal), Vikedalselva (acidification, montain-boreal-lowland). • Monitoring liming/acidification: several rivers at the south and west of Norway. Some few in the north and east. • Oslo rivers pollution monitoring (very 2-5 years), some ”references”? • Almost all other Norwegian invertebrate data is from short time point source monitoring. • Lack of additional data to define reference conditions

7. Methods • Sampling: mostly 3x1 min kick, some 5x1 min, 1x1 min, some with no time frame. • Sorting: no systematic common approach (NIVA: subsampling, counting all in 1. subsample, then the less common (< 20) in next samples, all subsamples to look for species in few numbers.) • Taxa level: All to main groups, EPT to species, elmiidae to species and few other groups. • Sampling frequency: 1-2 times/year (prefer autumn)

8. Classification • No national system (or under development?) • Raddum (national monitoring acidification/liming), NIVA (regional east) • ASPT (depending on institution/person) • EPT (depending on institution/person) • Trent modified (Oslo rivers)

9. Supporting information • Acidification: pH, alk, and most anions and cations • Other monitored variables depend on the purpose • Problem: when chemical variables and macroinvertebrates have been monitored in the same program (acidification/liming), there have often been lack og coordination in time and site.