The park also included a coin-operated arcade in which human visitors would "compete" in games like Tic-tac-toe against chickens, whose "moves" in the game were determined by pecking lights which appeared only on the chicken's side of the machine. At its peak, Aquarena Springs attracted 250,000 visitors annually. The center added a Wetlands Boardwalk in a shallow area of Spring Lake. The boardwalk, made of recycled plastic lumber, floats on the water and circles a marshy area that showcases the flora and fauna of a wetland ecosystem. Aquarena Center was designated as a "critical habitat," subject to the Endangered Species Act, because the springs are home to the fountain darter, the Texas Blind Salamander, the San Marcos Salamander, the San Marcos gambusia, and Texas Wild Rice. The San Marcos gambusia may be extinct as none have been seen since 1983. The main aim of the center is research. The MCWE participates in underwater archaeology. It searches for Henry Morgan’s lost fleet while exploring caves in Mexico, Spring Lake, and shipwrecks. The center uses unmanned aircraft (Unmanned Autonomous Vehicle) to capture photos and gather information for projects related to fisheries, wildlife, and watershed management and restoration. The Meadows Center is dedicated to the sustainable management of the world’s freshwater resources. They oversee the Spring Lake Management Plan, which is designed to protect healthy ecosystems, provide research and educational opportunities, and offer access for service activities. As active partners in the Edwards Aquifer Habitat Conservation Plan, they help ensure minimum continuous spring flows of the Comal and San Marcos Springs. The Aquarena Springs Amusement Park was the actual location of the resort in the 1978 film "Piranha", directed by Joe Dante.