the ecology of the lake. Fish stock has decreased dramatically and some endemic species (e.g. certain Chirostoma) are on the verge of extinction. Contaminated fish stock has also posed a serious threat to the health and livelihoods of people who depend on the fish for food. The drop in the lake's water level has uncovered political issues that had been hidden for many years. Its fast decay has raised concern in the surrounding areas and in the scientific community. It was the Global Nature Fund's "Threatened Lake of the Year" in 2004. By 2007 and 2008, the level of Lake Chapala had increased drastically, though the levels have yet to surpass the level in 1979, when the levels began a precipitous decline. Although it is still subject to agricultural, domestic, and industrial sources of contamination, the actual levels of hazardous materials has not been officially assessed with regularity. Although water level and quality improved due to water treatment plants along the Lerma river, in 2017 the water quality of Lake Chapala was assessed as a risk to public health. In 2018, the Lake Chapala water level was at 81.68% of capacity, up from 66.66% in 2017. Habitat and species The lake is a critical habitat for several species of migratory birds, such as the American white pelican, and home to thousands of indigenous plants and animals. The Audubonistas de Laguna de Chapala holds an annual Audubon Society sponsored Christmas Bird Count. In 2006, some 117 species were identified and, in 2007, the count was 125. By January 2011, some 173 species were recorded. The subspecies chapalaense of the rough-footed mud turtle is largely restricted to Lake Chapala, while the more widespread subspecies murrayi inhabits the Lerma River basin (and some other regions in northern Mexico). The essentially harmless, semi-aquatic obscurus subspecies of the Mexican garter snake is restricted to the lake. In addition to the Chirostoma ("charales") species flock of fish, the lake and associated rivers are home to many other endemics, including several goodeids, a few Algansea chubs, two Tetrapleurodon lampreys, two Ictalurus catfish, the Chapala chub (Yuriria chapalae) and more. Several of these are highly threatened. Other aquatic species found only in the lake and associated water systems are four cambarid crayfish: Cambarellus chapalanus, C. lermensis, C. prolixus and Procambarus digueti. Communities There are numerous towns and cities along the coast of Lake Chapala, including San Juan Tecomatlan,