The municipality of Zoetermeer has constructed a swamp pearl along the Broekwegkade. Marsh pearls are habitats where special plant species can thrive. These plant species in turn attract animal species such as reed birds, butterflies, water shrews, amphibians, dragonflies and owls. The water plants in this swamp pearl have a purifying effect. By allowing water from the Zoetermeerse Plas to flow slowly through this area, nutrients from this water are absorbed by the plants and micro-organisms in the marsh pearl in the hope that this will help prevent the formation of blue-green algae. This is a common problem in the summer in the Zoetermeerse Plas. Marsh pearls have also been created in other places in Zoetermeer. At the Zoetermeerse Plas (de Beren), the Prielenbos (het Geertje) and at the Benthuizerplas.