1. Sunlight causes DNA to break down.
2. If eDNA is exposed to too much sunlight, it breaks down into smaller pieces which cannot be detected by the eDNA test.
3. Waterholes protected from sunlight by nearby cliffs or trees that provide shade may have better quality eDNA.
4. Some waterholes have muddy water.
5. Muddy water can clog up filters when filtering water samples.
6. The eDNA in the sample then gets stuck and cannot be purified for testing.
7. Muddy water also contains more bacteria and enzymes.
8. Some bacteria and enzymes consume and break down DNA so it can no longer be detected by the eDNA test.
9. If the amount of DNA in a sample is too low, it may not be found by the test.
10. A large waterhole may water down DNA making it harder to find.
11. Or, a small number of birds can lead to only a small amount of DNA being shed into the waterhole.
12. More DNA in a sample will lead to better results.
13. To increase chances of finding eDNA, at least three samples should be collected from each waterhole.
14. Samples must be collected under clean conditions.
15. When collecting samples gloves must be worn to ensure the samples are clean.
16. Dirty hands, gloves or bottles can contaminate the sample by adding DNA from other waterholes.
17. The best results are expected from waterholes that are shaded, clean, small and have lots of birds visiting!
18. Although some waterholes may have characteristics that are bad for eDNA, sometimes eDNA can still be found!