US Fish & Wildlife Service


Date of this Version



Published in Contaminant Report Number: R6/707C/93, 1-37, (1993)


Bamforth National Wildlife Refuge (Bamforth) located in southeast
Wyoming serves as an important resting area for several species of migratory
waterbirds. Surveys were conducted in the summer months of 1992 to
determine bird use at Bamforth. Sediment, water, and biota were collected
from Bamforth to identify wetlands with potential contaminant problems that
may be affecting migratory waterbirds. Mercury and lead in water samples
were above criteria for the protection of aquatic life. Selenium levels in
vegetation and sediment were elevated above concentrations documented to
bioaccumulate and cause adverse reproductive effects in waterfowl. Selenium
levels in waterbird eggs were slightly greater than background concentrations
but no deformities in embryos were found. Arsenic concentrations in aquatic
invertebrates and vegetation were elevated to levels that may be harmful to
waterfowl who consume these items Water from Bamforth Lake, South Pond,
and the southeast seep were hypersaline brines. Salt toxicosis in waterbirds
was not observed in this study, but maintaining existing freshwater sources
such as a nearby stock pond may reduce the likelihood of salt toxicosis in the
numerous waterbirds that come to rest, feed, or nest at Bamforth. Periodic
monitoring of trace elements and the occurrence of salt toxicosis in waterbirds
at Bamforth is recommended .