Me. Eiswerth et al., Potential environmental impacts and economic damages of Eurasian watermilfoil (Myriophyllum spicatum) in western Nevada and northeastern California, WEED TECH, 14(3), 2000, pp. 511-518
Eurasian watermilfoil, an aquatic invasive weed, has been identified recent
ly at a number of sites in western Nevada and northeastern California, incl
uding Lake Tahoe. Because Eurasian watermilfoil is easily spread by fragmen
ts, transport on boats and boating equipment plays a key role in contaminat
ing new water bodies. This is an important means of the potential spread of
this weed throughout key recreational and agricultural areas surrounding L
ake Tahoe. Unless the weed is controlled, significant alterations of aquati
c ecosystems, with associated degradation of natural resources and economic
damages to human uses of those resources, may occur. This research uses th
e economic valuation approach known as benefits transfer to estimate the va
lue of a portion of the recreational service flows that society currently e
njoys in the Truckee River watershed below Lake Tahoe. The lower-bound esti
mates of baseline water-based recreation value at a subset of sites in the
watershed range from $30 to $45 million/yr. Impacts from the continued spre
ad of Eurasian watermilfoil in the watershed could be significant; for exam
ple, even a 1% decrease in recreation values would correspond to roughly $5
00,000/yr as a lower bound.