- Freshwater & Marine Ecology 11
- Geology 10
- Climate Change 7
- Paleontology 7
- Physical Geography 7
- Sedimentology 7
- Ecology 5
- Zoology 4
- Ecotoxicology 3
- Hydrogeology 3
- Water Quality/Water Pollution 3
- Atmospheric Protection/Air Quality Control/Air Pollution 2
- Environment, general 2
- Industrial Pollution Prevention 2
- Mineral Resources 2
- Soil Science & Conservation 2
- Biogeosciences 1
- Climate Change/Climate Change Impacts 1
- Environmental Management 1
- Environmental Physics 1