The border fence erected and extended by the United States Department of Homeland Security to prevent undocumented immigration has had extremely negative effects on wildlife, including endangered species, whose habitats and ranges lie in the transboundary region (López-Ho man, Varady, and Balvanera 2009; Segee and Córdova 2009; Si- erra Club 2010). The fence deters virtually all wildlife crossings, cutting animals and reptiles off from sources of water, food, and access to habitat and to potential mates.
Wetlands are a critical source of biodiversity and losses of wetlands may be irreversible, limiting or prohibiting future e orts at restoration (Beibighauser 2007). At-risk estuaries include the Tijuana River and the Rio Grande, including the adjacent Laguna Madre coastal lagoon (Liverman et al. 1999). The Rio Grande is also home to endangered silvery minnows in the last remnant of their historical habitat and to flocks of migrating cranes and geese who gather in vast numbers to rest and refuge in riparian bosques (woodlands) (Hurd and Coonrod 2008). Native fish, neotropical songbirds, and migratory waterfowl, including threatened and endangered species, have all declined precipitously in recent decades (Lacewell et al. 2010).
Two principal vulnerabilities associated with the Lower Colorado River and delta are (1) the lack of dedicated ecological flows to sustain critical wetlands and bird habitat in the delta; and (2) the over-allocation of Colorado River water and over-reliance of the seven U.S. basin states and Sonora and Baja California on its water as a principal source of supply
Likely effects of the climate changes described in Table 16.1 are primarily associated with increasing temperatures, declining precipitation and stream flows, and increasing extreme events (i.e., droughts).
The Colorado River delta has been called “one of the most important estuaries in the world” (Zamora-Arroyo and Flessa 2009, 23) and is the largest remaining wetland system in southwestern North America.
Wetlands are a critical source of biodiversity and losses of wetlands may be irreversible, limiting or prohibiting future e orts at restoration (Beibighauser 2007). At-risk estuaries include the Tijuana River and the Rio Grande, including the adjacent Laguna Madre coastal lagoon (Liverman et al. 1999). The Rio Grande is also home to endangered silvery minnows in the last remnant of their historical habitat and to flocks of migrating cranes and geese who gather in vast numbers to rest and refuge in riparian bosques (woodlands) (Hurd and Coonrod 2008). Native fish, neotropical songbirds, and migratory waterfowl, including threatened and endangered species, have all declined precipitously in recent decades (Lacewell et al. 2010).
Two principal vulnerabilities associated with the Lower Colorado River and delta are (1) the lack of dedicated ecological flows to sustain critical wetlands and bird habitat in the delta; and (2) the over-allocation of Colorado River water and over-reliance of the seven U.S. basin states and Sonora and Baja California on its water as a principal source of supply
Likely effects of the climate changes described in Table 16.1 are primarily associated with increasing temperatures, declining precipitation and stream flows, and increasing extreme events (i.e., droughts).
The Colorado River delta has been called “one of the most important estuaries in the world” (Zamora-Arroyo and Flessa 2009, 23) and is the largest remaining wetland system in southwestern North America.