Stockbysjön

Stockbysjön is a small forest lake dominated by vegetation. The surface area of the lake is about 2.4 hectares and the maximum depth is just over two meters. The lake is largely surrounded by swamp forest, but there are some beach rocks in the southern part of the lake and a small gravel beach in the northern part of the lake.

The lake has high natural values and has a rich bottom vegetation and a rich animal life. Among the rarer benthic animals is the ribbed mussel.

At Stockbysjön, 27 of Lidingö's 30 dragonfly species have been observed, making the lake Lidingö's richest dragonfly habitat.

The water to the lake is treated in two stormwater ponds and an overflow area before it reaches the lake. The lake is small and therefore has a faster water turnover time than Kottlasjön.

Until a few years ago, large parts of the lake bottom were covered by the unusual crane's foot algae. In 2021, only a few specimens of crane's foot algae remained. Instead, fine-grained algae, such as green algae, have spread in the lake. In the summer of 2020, large parts of the lake were covered by the fine filamentous algae that had floated to the surface. As there was also a lot of fine filamentous algae at the beginning of summer 2021, there is a high risk that large parts of the lake's surface will be covered by a carpet of fine filamentous algae again this year. It is unclear what caused this change, but the City of Lidingö is continuing to investigate the lake to find an explanation for the change.