Table 1. Summary of lake data for each samples lakes (-: data not known).
| Lakes | Country | Sampling date | Coordinates | Area (km2) | G. semen abundance (cells L−1) | Monitoring period | Known G. semen occurrence years |
| Mjöträsket | Sweden | 6 July | 65°55′55″N 23°05′50″E | 2.56 | 4200 | 2006 | 2006 |
| Sidensjön | 8 July | 63°53′12″N 19°48′53″E | 0.089 | 117200 | 2004–2010 | 2004–2010 | |
| Ekholmssjön | 11 Aug | 59°52′19″N 17°03′36″E | 0.057 | 34700 | 1995–2010 | 1995–2010 | |
| Lillsjön | 10 Aug | 58°48′06″N 17°26′37″E | - | 30000 | - | - | |
| Stråken | 5 Aug | 57°07′11″N 14°34′10″E | 7.7 | 26000 | - | 1948 | |
| Helgasjön Station 2 | 4 Aug | 56°58′42″N 14°42′21″E | 50.2 | 3200 | - | - | |
| Helgasjön Station 1 | 4 Aug | 56°55′26″N 14°49′24″E | 50.2 | 1800 | - | 1948 | |
| Liasjön | 23 July | 56°26′78″N 13°59′56″E | 0.12 | 408000 | - | - | |
| Lundebyvatn | Norway | 28 July | 59°32′48″N 11°28′57″E | 0.42 | 286300 | 2005–2010 | 2005–2010 |
| Gjølsjøen | 28 July | 59°26′24″N 11°41′01″E | 0.98 | 14800 | - | - | |
| Isesjøen | 28 July | 59°17′42″N 11°14′40″E | 6.35 | 60200 | 2005–2010 | 2005–2010 | |
| Kylänalanen | Finland | 20 July | 60°24′21″N 23°45′01″E | - | 5100 | - | 2004 |