Located in the Regional Natural Park of Ballons des Vosges, the Gérardmer territory is home to five protected natural sites and a National Nature Reserve. Perennial amphibious meadows and, more particularly, those with boréomontane affinities are specialized plant communities in water bodies. Two Isoetes and aquatic Subularia species are now threatened in the Vosges' lakes. The Conservatory of Natural Areas of Lorraine and the Gerardmer Fishing Society have installed a cage that is supposed to protect the isoete. The small one-meter-by-one wire mesh was placed about six feet deep by two CEN divers.