A literature review, conducted during the initial phases of the project concluded that:
- eutrophication calculations could be improved with more measurements of phytoplankton and oxygen
- the global coverage of river discharge and or drainage area ranges from 40 to 67% for most major water quality attributes but drops to 25% for some organic and/or particulate forms of N and P
- Consistency of fauna abundance data is badly lacking. There is an uneven quality of alien species distributional data