PRELIMINARY-OBSERVATIONS ON RESPONSES OF EMBRYONIC AND LARVAL PACIFICHERRING, CLUPEA-PALLASI, TO NEUTRAL FRACTION BIODEGRADATION PRODUCTS OF WEATHERED ALASKA NORTH SLOPE OIL
Dp. Middaugh et al., PRELIMINARY-OBSERVATIONS ON RESPONSES OF EMBRYONIC AND LARVAL PACIFICHERRING, CLUPEA-PALLASI, TO NEUTRAL FRACTION BIODEGRADATION PRODUCTS OF WEATHERED ALASKA NORTH SLOPE OIL, Archives of environmental contamination and toxicology, 34(2), 1998, pp. 188-196
Weathered Alaska North Slope crude oil (ANS 521) was subjected to biod
egradation in vigorously stirred incubations for 14 days at 15 +/- 1 d
egrees C in 20 parts per thousand salinity sterilized seawater, amende
d with nutrients and inoculated with a hydrocarbon-degrading microorga
nism (EI2V) isolated from an oil-contaminated beach in Prince William
Sound, Alaska. A total of 13.7 mg/L water-soluble neutral fraction (WS
F) was recovered from the incubation of weathered ANS 521. Toxicity/te
ratogenicity tests were conducted with WSF recovered from the biodegra
dation system using embryonic and larval Pacific herring, Clupea palla
si. Exposures fl;ere begun at 4, 48, and 96 h postfertilization of her
ring eggs. Exposure concentrations were 1, 10, and 100% of the origina
l concentration of WSF recovered from incubations (redissolved in 20 p
arts per thousand salinity sterile seawater at 15 +/- 1 degrees C)., S
terile 20 parts per thousand salinity seawater without the addition of
redissolved neutral fraction was used as a control, Significant (p le
ss than or equal to 0.05) embryo mortality or teratogenic responses we
re observed at WSF concentrations of 10 and 100%. On days 5 through 8
of embryogenesis, counts of heart contraction rates were significantly
lower (p less than or equal to: 0.05) at the 100% WSF concentration f
or embryos exposed beginning at 4 and 48 h postfertilization. Grow-out
of larvae from selected exposures was conducted, High mortality was n
oted in larvae exposed to the 10% WSF concentration beginning at 4 and
?8 h postfertilization., Most of these larvae died 5 to 8 days after
hatching when they elicited vertebral displacements at a time concurre
nt with the onset of feeding behavior.