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Show cultivation and irrigation of these lands has eliminated the habitat for most desert species. This trend has been particularly true for lizards. The western leopard frog and the western chorus frog are common along most ditches and irrigated fieldse The large woodhouse toad has steadily declined in this area because its life pattern has been disrupted by man's activitieso A modest population of tiger salamanders inhabits the valleys of this area,, The bullfrog has been introduced in a number of ponds for its food value; however, only a few of these introductions have been successful. Wandering garter snakes and redsided garter snakes are common. The night snake and the striped racer occur at the margins of cultivated areas but rarely enter theme The lizards are found near the edges of cultivated and irrigated areas. e„ Aquatic Invertebrates Throughout the centuries aquatic invertebrates have evolved into hundreds of species inhabiting a variety of micro- environments, each characterized by a specific set of often rigid conditions. The use of such organisms as indicators to evaluate environmental changes is a widely accepted ecological technique. In order to apply this technique, it is necessary to have thoroughly studied existing populations and to have established baseline estimates of quality and quantity. The invertebrates must be studied further to monitor and evaluate the effects of the environmental alteration upon their populations. The initial step in establishing such a program is the compilation of a checklist for the area in question. The Center for Health and Environmental Studies, Brigham Young University, has prepared such a listing for selected representative locations within the boundaries of the Bonneville Unit. These tabulations which were derived from a search of the literature supplemented by a few field trips, are presented in Attachment F, tables 1 through 11o The locations chosen for study were Rock Creek, Duchesne River, Currant Creek, Strawberry Reservoir ( limited to the existing reservoir), Diamond Fork, Spanish Fork River, Provo River, Utah Lake, Mona Reservoir, and Jordan River. Some interpretation of the ecological significance of the aquatic organisms inhabiting the areas covered by the checklists is available only for Goshen Bay area of Utah Lake* ° One purpose of the Goshen Bay Study is to evaluate the probable effects of the proposed diking upon bottom invertebrates. Samplings have been designed to cover areas both inside and outside the location of the proposed dike. The dominant bottom type in this area, as in the whole lake, 145 |