OIL AND RELATED CHEMICALS - Marine Pollution: What Everyone Needs to Know - page 74

Sound in Alaska retained oil for many years after the massive
oil spill of the Exxon Valdez in 1989. What remains controver-
sial is how long the effects persisted. In a cold environment
like Alaska oil degrades much more slowly than in warmer
regions, and salmon embryos in the sediments a decade later
did not develop properly. After over a decade pockets of oil
remained in these marshes, and mussels, clams, harlequin
ducks, and other birds that feed on sediment-dwelling inverte-
brates showed evidence of harm in some localized areas. Fish
embryos continued to be affected by oil trapped in gravel and
sediments for many years after the spill, according to Ronald
Heintz and colleagues from NOAA.
Knowledge about long-term consequences of spilled oil
should be included when assessing oil-impacted areas. It will
take many years to understand the overall impacts of the enor-
mous oil pollution that gushed into the Gulf of Mexico from
the Deepwater Horizon in the spring and summer of 2010.
How does oil harm marine birds and mammals?
There are three primary ways oil injures wildlife: (1) it coats
the fur and feathers and destroys the insulation causing the
animals to die of hypothermia (they get too cold); (2) animals
eat the oil, either while trying to clean it off their fur and feath-
ers or while scavenging, and the oil is toxic; (3) oil impairs
them in long-term chronic ways, such as damaging the liver or
impairing reproduction. An impaired animal cannot compete
for food and avoid predators.
What kinds of toxic effects does oil produce in
other marine animals?
Corals
An oil spill in Panama initially caused coral bleaching (sym-
biotic algae are expelled from coral tissue), tissue swelling,