Preface
Today's natural resource managers must respond to a wide array of
challenges that threaten to disrupt the biological integrity and
sustainability of aquatic ecosystems. Nowhere is this more evident than
in the challenges brought on by environmental contaminants. Notable
among these pollutants is selenium, a naturally occurring trace element that can be concentrated and released in the waste materials
from certain agricultural, petrochemical, mining, and industrial activities. Once in the aquatic environment, selenium can rapidly
bioaccumulate and reach levels that are toxic to fish and wildlife. Over
the past 20 years this threat has become a reality at several locations
across the United States. Two examples are Belews Lake, NC, where
19 species of fish were eliminated due to selenium discharged from a
coal-fired power plant, and Kesterson National Wildlife Refuge, CA,
where thousands of migratory waterbirds were poisoned by selenium
in agricultural irrigation drainage. During the last decade, cases of
selenium contamination have emerged on a global scale. Argentina,
Australia, Canada, China, Egypt, Greece, India, and Russia are just a
few of the locations where aquatic habitats have been impacted.
This escalation in selenium issues has prompted increased efforts to
identify and characterize toxic hazards and to develop water quality
criteria. The success of these efforts depends on having technically
sound, selenium-specific procedures and methods that can be applied
across a wide range of habitat types and environmental conditions. I
have spent the past 20 years engaged in the development and testing
of methods and guidelines for selenium assessment, beginning with
field studies that led to new US water quality criteria for selenium in
the mid-1980s, and culminating with the recent completion of a procedure for setting aquatic ecosystem loading limits. The interest in this
information is growing rapidly. During the past 3 years, I have received over 500 requests for assistance on a variety of selenium issues
from 64 countries around the world. Until now, I have only been able
to provide assistance on a piecemeal basis, since no single publication
ix
Today's natural resource managers must respond to a wide array of
challenges that threaten to disrupt the biological integrity and
sustainability of aquatic ecosystems. Nowhere is this more evident than
in the challenges brought on by environmental contaminants. Notable
among these pollutants is selenium, a naturally occurring trace element that can be concentrated and released in the waste materials
from certain agricultural, petrochemical, mining, and industrial activities. Once in the aquatic environment, selenium can rapidly
bioaccumulate and reach levels that are toxic to fish and wildlife. Over
the past 20 years this threat has become a reality at several locations
across the United States. Two examples are Belews Lake, NC, where
19 species of fish were eliminated due to selenium discharged from a
coal-fired power plant, and Kesterson National Wildlife Refuge, CA,
where thousands of migratory waterbirds were poisoned by selenium
in agricultural irrigation drainage. During the last decade, cases of
selenium contamination have emerged on a global scale. Argentina,
Australia, Canada, China, Egypt, Greece, India, and Russia are just a
few of the locations where aquatic habitats have been impacted.
This escalation in selenium issues has prompted increased efforts to
identify and characterize toxic hazards and to develop water quality
criteria. The success of these efforts depends on having technically
sound, selenium-specific procedures and methods that can be applied
across a wide range of habitat types and environmental conditions. I
have spent the past 20 years engaged in the development and testing
of methods and guidelines for selenium assessment, beginning with
field studies that led to new US water quality criteria for selenium in
the mid-1980s, and culminating with the recent completion of a procedure for setting aquatic ecosystem loading limits. The interest in this
information is growing rapidly. During the past 3 years, I have received over 500 requests for assistance on a variety of selenium issues
from 64 countries around the world. Until now, I have only been able
to provide assistance on a piecemeal basis, since no single publication
ix