ESWR page - Endangered Species & Wetlands Report

less than 100, the delta smelt is now at risk for loss of its genetic integrity and at greater
risk of extinction than when the species was listed under the ESA.
III. CONCLUSION
The USFWS (2004b) recently concluded that the threats to delta smelt described in the
original listing remain, including the destruction, modification, or curtailment of the delta
smelt’s habitat or range resulting from extreme freshwater outflow conditions (reduced
outflow or high outflow), operations of the State and Federal water projects, and other
water diversions. CDFG (2003) and Moyle (2002, 2003) concluded that these threats
could result in the extinction of the delta smelt. In addition, any one of the many
stochastic factors that affect delta smelt, such as predation, invasive species, change in
food organisms, toxic substances, disease, competition, and entrainment losses to water
diversions can cause their numbers to move towards extinction (Moyle 2002, 2003).
In 2003, the USFWS (2004b) concluded that new information concerning the delta
smelt’s population size and extinction probability indicated that the population was at risk
of falling below an effective population size and therefore in danger of becoming extinct.
Since the USFWS status review, the delta smelt population has indeed fallen below an
effective population size and is therefore in danger of becoming extinct.
Recent population viability and extinction risk analyses indicate that, conservatively, the
delta smelt could go extinct within the next 20 years and new analyses have demonstrated
a statistically significant relationship between delta smelt population abundance and
Delta export rates. Despite the availability of this new information regarding the
likelihood of extinction of the species and the delta smelt’s decline to record low levels
for two consecutive years (2004 and 2005), neither the USFWS nor other agencies
charged with protecting the delta smelt and its Delta habitat have taken major actions to
reverse the decline. Indeed, state and federal agencies continue to proceed with plans to
that would exacerbate current conditions for the delta smelt, including increasing export
levels at the Delta pumping facilities and developing new water diversion and storage
projects which will reduce Delta inflow and further degrade delta smelt habitat.
The warning signs could not be clearer: the delta smelt is at high risk of extinction. We
urgently petition the USFWS to list the delta smelt as endangered, and to immediately
implement measures to curtail threats to the species and improve environmental
conditions in its Delta habitat.
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