clean debris around the river with the use of canoes, or cook food for the San Marcos River Clean-Up thank-you dinner that is provided for all volunteers. The clean-up is coordinated yearly by Tom Goynes, president of the Texas River Protection Association, and is usually the first Saturday of every March. Wildlife San Marcos has many different wildlife species, including endangered ones, that reside in the San Marcos River. Species are listed threatened or endangered based on declining numbers or loss of habitat. The Texas blind salamander and the San Marcos salamander are endangered species that are only found in certain section of the San Marcos River and the Edwards Aquifer. Other endangered species include the fountain darter and San Marcos gambusia, which reside in the San Marcos River. The fountain darter is characterized by the mottled brown body and dark markings that help it camouflage into the bottom of the San Marcos River banks. It has a growing population and flourishes in the San Marcos River. The San Marcos gambusia is characterized by prominent dark stripes along its body. Its population is unknown, as no samples have been collected since 1983, and is even considered to be extinct. Both fish require clear, clean, continually flowing water with a stable temperature. An endangered plant species specific to the San Marcos River is Texas wild rice. Only 230 clumps still remain on the river in two different populations, with one population being grown on the Texas State University campus. The San Marcos River is considered to be one of the most biologically diverse aquatic ecosystems known in the Southwestern United States. Consequently, the United States Fish and Wildlife Service and Texas Parks and Wildlife Department have designated the San Marcos Springs and Spring Lake critical habitat, so some parts of the river are privatized. Critical habitat refers to a particular geographical area that contains all of the physical, chemical and biological attributes needed for the continued success of an endangered plant or animal and that may require special efforts for their management and protection. Restoration efforts Much of the San Marcos River is protected by the Edwards Aquifer habitat conservation plan due to the wildlife that reside in or near the river. This plan was established in 2006 as an attempt between several Texas cities that use the many resources of the San Marcos River to manage aquatic habitats and water