Siikalahti Bay, one of the most famous wetlands in Finland, is a sheltered, shallow bay of Simpele lake. It is heavily vegetated with Phragmites, Typha and floating plants like Nymphaea, with open water constituting no more than 25% of the lake area. Eutrophication is mostly due to the input of large amounts of nutrient run-off from adjacent farmlands and sewage disposal from nearby settlements. Sammallampi lake, connected to Siikalahti Bay via the Simpele lake water system, is a small eutrophic lake surrounded by farmlands and forests. The vegetation is similar to Siikalahti, but overgrowth does not pose a significant threat in the near future.
Very important for wetland breeding birds. Species of global conservation concern that do not meet IBA criteria: Anser erythropus (max. 1, passage), Crex crex (1 pair, breeding).
Pressure/threats to key biodiversity
Although Siikalahti was purchased by the state, its future does not seem promising since overgrowth of vegetation has continued despite some restoration trials. Hunting is forbidden at Siikalahti, but heavy at Sammallampi. The impact on the birds of large-scale nature tourism at Siikalahti is probably minor, as it is concentrated in the vicinity of the tourist centre and a birdwatching tower.
National None International High512 ha of IBA covered by three Special Protection Areas (Siikalahti, Sammallampi, and Rautalahti).