Selenium-Induced Developmental
Effects Among Fishes in Select West
Virginia Waters
West Virginia Department of Environmental Protection
Selenium is a naturally occurring element that is found in
Cretaceous marine sedimentary rocks, coal and other fossil
fuel deposits.
Se is toxic in large amounts, but trace amounts of it, forming
the active center of certain enzymes, are necessary for the
function of all cells in (probably) all living organisms.
Studies are being performed by DEP on bioaccumulation of
Se in freshwater fishes at locations susceptible to elevated
Se inputs and determine if developmental impacts are
present among select ichthyoplankton.
Sulfur
Selenium
Electron
Configurations
Crystal
Structures
•Mediator of health benefits
•Found in the form of selenocysteine (Sec), the “21st” amino acid
•Essential component of glutathione
peroxidase, an enzyme that prevents
free radical damage to cells
(an antioxidant)
•Other Selenoprotein Functions:
•Muscle & RBC integrity
•DNA-RNA synthesis
•Detoxification of metals
•Gametogenesis
•Cellular respiration
•Antibody synthesis
•Phenomenon resulting from
excessive selenium availability
•Occurs when selenium replaces
sulfur in the synthesis of cysteine or
methionine
•The resultant selenoamino acid is
inserted in place of a natural amino
acid
•Disrupts sulfur-to-sulfur linkages
and impedes coiling of protein
molecule into tertiary (helix)
structure
•Creates improperly formed and
dysfunctional proteins and enzymes
Seleniferous Zone
Coal Seams
Fly Ash
Deposition
Selenate—Se (VI)
Selenate to Selenite Se (IV)
Selenium Study Sites
Coal-containing
Geology
Selenium Study Sites
Connor Run
Daugherty Run
Elk Fork Lake
Hughes Fork
Mount Storm
Lake
Little Scary Creek
Ash Fork
Upper Mud
River Rsvr.
White Oak Creek
Kiah Creek
East Lynn
Lake
Mud River
Beech Creek
Plum Orchard Lake
Sycamore Creek
Seng Creek
Pond Fork
Valley Fill Influenced
Fly Ash Influenced
Headwaters of Little Scary Creek
Headwaters of Mud River
1. Agricultural
irrigation of
seleniferous soils
2. Landfill deposition
of coal ash
3. Large-scale
disturbances of
rock strata,
particularly
surrounding coal
4. Livestock feedlot
and rearing facility
waste ponds
5. Phosphorus mine
wastes
60
50
40
Total Se
30
20
10
0
Average Fish Tissue Concentration vs Average Column
Concentration
avg fish tissue conc. (ppm)
average column conc. (ppb)
Why it Matters:
1. Sensitive due to proteindependent egg & larval
stages
2. Passed from mother to
offspring in ovary
3. Embryos exposed to
elevated selenium
incorporate
dysfunctional into
tissues
4. Resultant larvae are
either not viable or
teratogenically mutated
Yolk-Sac Larvae
32-Celled
Embryo
Embryonic
Differentiation
Normal 2-4 day larvae
straight spine
1. pointed head
2. gaping jaw
3. kyphosis
4. lordosis
5. delayed yolk
absorption
Abnormal development
Normal 2-4 day larvae
straight spine
1. pointed head
2. gaping jaw
3. kyphosis
4. lordosis
5. delayed yolk
absorption
Abnormal development
Why it Matters:
1. Sensitive due to proteindependent egg & larval
stages
2. Passed from mother to
offspring in ovary
3. Embryos exposed to
elevated selenium
incorporate
dysfunctional into
tissues
Yolk-Sac Larvae
32-Celled
Embryo
4. Resultant larvae are
either not viable or
teratogenically mutated
Embryonic
Differentiation