Habitat Degradation. Water Diversions, Spring Development, and Water Development Water diversions and groundwater development may be a continuing threat to relict leopard frog conservation where historical populations have been extirpated or their habitats altered due to diversion of water from streams or wetlands for activities associated with livestock grazing, agriculture, urban development, and other uses. Because of legal appropriations under Arizona, California, Nevada, and Utah water laws and land use practices on public, private, and tribal lands, water diversions continue to occur and may be problematic for relict leopard frog conservation and management of occupied or historical leopard frog habitats. Extant populations are restricted to perennial desert springs along the Virgin and Colorado river drainages. Substantial leopard frog habitat in the historical range of the relict leopard frog has been destroyed or modified by activities such as spring capping and diversions and the construction of dams and reservoirs. Modifications have not only changed the amount and quality of habitat available for relict leopard frogs, but may also have created habitat for and promoted introduction of nonnative predators (Sredl et al. 1997). In addition to local spring and stream modifications, aquifer overdrafting in areas that affect relict leopard frog habitat may be a significant threat, because these aquifers may be limited in their ability to recharge. Possible explanations of the origin of these springs and impacts that might occur from future groundwater withdrawal are considered below.
Habitat Degradation. Major threats in this GMU are: degradation of habitat due to livestock grazing, oil and gas exploration, and alteration of wetland/spring complexes due to groundwater withdrawal. Livestock grazing specifically impacts the habitat by trampling shorelines, reducing vegetation, decreasing water quality, and accelerating succession of spring complexes. Oil and gas exploration may lead to a decrease in water quality, water contamination, and potentially alter groundwater pathways. Alterations to wetland/spring habitat include diversions for agricultural or municipal purposes. Water withdrawals are currently proposed to support human population growth in Southern Nevada may impact ground water levels in the Snake Valley (Xxxxx and Xxxxxx 2005). Detrimental Interactions: Several nonnative species have been introduced into some of the subunits for purposes ranging from mosquito abatement to recreational fishing opportunities. Competition and predation by nonnative species has significantly impacted least chub populations and poses a potential threat in this GMU. West Desert GMU Conservation Elements Habitat Protection, Nonnative Control, Range Expansion, Restore Hydrologic Conditions, Monitoring
Habitat Degradation. The major threat in this area is loss of habitat due to human growth and water development for municipal and agricultural purposes. Agricultural areas and mountain foothills have been converted into neighborhoods and wetland areas in the valleys have been drained and diked. Water development projects have caused a reduction in habitat due to decreased water levels and elimination of habitat. Detrimental Interactions: Several nonnative fish species have been introduced into these areas for purposes of mosquito abatement and recreational fishing opportunities. Competition and predation by nonnative species have significantly impacted least chub populations and will continue to present a threat. Wasatch Front GMU Conservation Elements Inventories, Habitat Enhancement, Habitat Protection, Nonnative Control, Range Expansion, Monitoring, Restore Hydrologic Condition
Habitat Degradation. The major threat in this area is loss of habitat due to livestock grazing, water development for municipal and agricultural purposes and potential peat mining in the Xxxxx Valley. Livestock grazing specifically impacts the habitat by trampling banks, reducing vegetation, and decreasing water quality. Habitat alteration has caused significant losses in habitat due to wetlands being filled or drained to create additional land for agriculture and development. Water development projects have caused a reduction in habitat due to decreased water levels, capping and drying of spring complexes. Peat mining has the potential to permanently altering the hydrology and habitat complexity making it unsuitable for least chub. Detrimental Interactions: Several nonnative fish species have been introduced into these areas for purposes ranging from mosquito abatement to recreational fishing opportunities. Competition and predation by nonnative species has significantly impacted historical least chub populations and may continue to present a threat in this unit. Xxxxxx River GMU Conservation Elements Inventories, Habitat Enhancement, Habitat Protection, Nonnative Control, Range Expansion, Monitoring, Restore Hydrologic Condition
Habitat Degradation. The present or threatened destruction, modification, or curtailment of Columbia spotted frog habitat or range. Water Diversions: Water diversions may be a significant threat to Columbia spotted frogs due to the removal of water from streams or wetlands for activities associated with livestock grazing and agriculture, particularly where drainages terminate and water becomes a limiting factor. Because of appropriations under state of Nevada water law and land use practices on public, private, and tribal lands, water diversions continue to occur and may be problematic for Columbia spotted frog conservation and recovery in some locations, particularly at lower elevations (Reaser 1997, USFWS 1993).
Habitat Degradation. The present or threatened destruction, modification, or curtailment of Toiyabe spotted frog habitat or range. Water Diversions: Water diversions may be a significant threat to Toiyabe spotted frogs where historic populations have been extirpated due to the diversion of water from streams or wetlands for activities associated with livestock grazing, agriculture, and fish culture, particularly where drainages terminate and water becomes a limiting factor. Because of appropriations under State of Nevada water law and land use practices on public, private, and tribal lands, water diversions continue to occur and may be problematic for Toiyabe spotted frog conservation and recovery in some locations, particularly at lower elevations (Reaser 1997; Worthing 1993).
Habitat Degradation. The major threat in this area is loss of habitat due to agricultural practices and water development for municipal and agricultural purposes. Livestock grazing specifically impacts the habitat by trampling, reducing vegetation, and decreasing water quality. Other agricultural practices such as cropland development have also significantly impacted Columbia spotted frog populations and habitat. Water development projects have caused a reduction in habitat due to decreased water levels and the capping and drying of spring complexes. Table 3. Summary of subunits containing Columbia spotted frog populations within the Xxxxxx River GMU. Subunit Population San Pitch River Fairview: Xxxxxxx south to Mt. Pleasant Middle Xxxxxx River No historic or currentoccurrences Lower Xxxxxx River No historic or current occurrences Detrimental Interactions In addition to habitat loss, nonnative species introduction poses a significant threat to spotted frog. Several nonnative fish species have been introduced into these areas for purposes ranging from mosquito abatement to recreational fishing opportunities. Competition and predation by nonnative species has significantly impacted spotted frog populations and continues to present a threat in this unit. Those non-natives that pose an immediate or potential threat to the Columbia spotted frog are: largemouth bass, rainbow trout, brown trout, xxxxx xxxxx, common carp, Western mosquitofish, rainwater killifish, plains killifish, fathead minnow, American bullfrog, and Raccoons. Conservation Actions Range Expansion, Habitat Enhancement, Nonnative Control, Habitat Protection, Restore Hydrologic Conditions, Monitoring, Mitigation, Regulations WEST DESERT GEOGRAPHIC MANAGEMENT UNIT Populations of spotted frog are currently known to exist in Tule Valley, Snake Valley, and Ibapah Valley subunits. The Tule Valley subunit is located between the House Range and the Confusion Range in Juab County. Populations of spotted frog occur at Coyote Spring, Willow Spring, North Tule and South Tule. Snake Valley subunit is located between the Deep Creek Mountains and the Confusion Range. Currently occupied areas within Snake Valley include Xxxxxx Spring Complex, Xxxxx Salt Xxxxx spring complex, Xxxxxx Xxxxxx spring complex, and Xxxxxx Spring, all of which spotted frog currently occur. Historic records have also been recorded in the Xxxxxx Spring and the Xxxxxx Spring Complexes. In the Ibapah Valley subunit, spotted frog occur along the valley floor whi...
Habitat Degradation. The habitat of Black Sea T. truncatus is used by humans for shipping, fishing, mineral exploitation, tourism, recreation, military exercises and waste disposal (Xxxxxxxx et al., 1983; Xxxxxxxxx et al., 1998; Xxxxxxxxxxxxx et al., 1998; Xxxxxx et al., 1998). Besides, coastal area and drainage basin are under a pressure from urban development, industry, hydro- and nuclear energetics, agriculture and land-improvement. Numerous anthropogenic threats responsible for bottlenose dolphins’ habitat degradation can be assembled into three principal groups: various kinds of pollution; physical modification of the seabed; and irretrievable take of natural wealth including the (over)exploitation of marine living resources.
Habitat Degradation. The present or potential destruction, modification, or curtailment of BCT habitat or range. Water Diversions and Development. Diversions of stream flows that alter natural flow patterns have been one of the greatest causes of habitat loss. Water diversions can interrupt historic flow timing, duration and magnitude or completely de-water stream segments. Diversions can fragment stream habitats and disconnect tributary streams from main stem rivers. In addition, unscreened diversions can attract migrating fish that can be lost during irrigation (Xxxxxx et al. 1996, Bain et al. 1988). Most diversions on streams in Nevada occur below preferred BCT habitat. Existing water diversions are present on Hampton Creek, Xxxxxx’x Creek, Mill Creek, Strawberry Creek, Xxxxx Creek, Goshute Creek, Pine/Ridge Creek, Big Wash and Snake Creek. Diversions within BCT habitat are present on Big Wash and Snake Creek. Livestock Grazing. Grazing has been shown to negatively influence stream habitats and stream communities (Xxxxxx and Xxxxxxx 1982, Platts and Xxxxxx 1985). Some past and current livestock grazing practices adversely impact BCT and their habitat. Poor grazing practices can alter sediment regimes and decrease streambank stability. Grazing can also detrimentally affect water quality, substrate composition and channel structure. Specific ramifications include loss of pool habitat, reduced instream cover, increased water temperature, and loss of quality substrate required for spawning and food production (Platts 1991, Xxxxxx 1999). Livestock grazing is currently present in riparian habitats along Xxxxx Creek, Deadman Creek, Strawberry Creek, Goshute Creek, Deep Creek, Big Wash, and Pine/Ridge Creeks. Timber Harvest. Logging has been reported to significantly affect salmonids, however, timber harvest does not pose a threat to BCT habitat in Nevada (Xxxxxxxxxx et al. 1991).
Habitat Degradation. The major threat in this GMU is loss of habitat due to livestock grazing, the threat of oil and gas exploration, alteration of wetland/spring complexes, and accelerated succession of spring complexes. Livestock grazing specifically impacts the habitat by trampling shorelines, reducing vegetation, and decreasing water quality. Oil and gas exploration may lead to decrease in water quality and water contamination. Alterations to wetland/spring habitat that include diversions for agricultural or municipal purposes is currently a significant threat, particularly in the Xxxxxx Springs complex.
