Parts of Lake Mandrensko are designated protected area s, Poda and Uzungeren, inhabited by a number of locally and globally endangered species of fish and birds.

It is located in a well-formed river valley, oriented transversely to the sea shore, as the mouth and the dam wall are in close proximity to the southern end of Bourgas.

The lake was preserved in its natural state until 1934, when corrections were made to some of the rivers and dikes were built in its western part to prevent spring floods.

In this way, part of the shallows overgrown with swamp vegetation were destroyed, the connection of the lake with the sea was cut off and it became completely freshwater.

The other lakes of the Mandra coast cover the northernmost slopes of Strandzha, with characteristic forest vegetation - cyclamen, wild peony, snowdrop, crocus and others.

The most important nesting place for birds is "Poda", the coastal meadows, the sandy shores - for the blue, the bee-eater, the red angel and others.