How would the populations of amphibians and small reptiles be affected if the fish population in the lake remained low for an extended period of time

Habitat loss and degradation is one of the greatest threats to amphibian and reptile populations and occurs from a variety of sources, including urban/suburban development, aquatic habitat alteration from water withdrawals and stream diversions, water pollution, and off-road vehicle use in terrestrial habitats. Declines in both population levels and species diversity have been attributed to habitat loss and degradation. Development can negatively affect habitat by destroying sites or degrading their quality, and by creating barriers or hazardous zones (e.g., a road) between important habitat features. Loss and degradation of habitat can disrupt population connectivity, diminishing the rate of dispersal and recolonization, such that local populations are unable to persist through natural catastrophes or population fluctuations.

For amphibians and aquatic reptiles (e.g., Mexican and narrow-headed gartersnakes [Thamnophis rufipunctatus]), the destruction of wetlands removes breeding sites and fragments populations, making these species more vulnerable to regional extirpation. For semi-aquatic and terrestrial reptiles, similar declines may occur. For example, individual desert tortoises occasionally move long distances between populations (Edwards et al. 2004). Historically, populations exchanged individuals at a rate > 1 migrant/generation. Such movements today are increasingly difficult for tortoises due to fragmentation of their habitat from landscape changes such as roads, housing developments, canals, and fences. Also, the loss of native bunchgrasses, from cattle grazing, in the Chiricahua mountains in southeastern Arizona was considered to be the main cause of a decline in the bunchgrass lizard (Sceloporus scalaris) (Ballinger and Congdon 1996). This lizard requires bunchgrasses for cover and protection from predators and harsh winter conditions.