|
Lessons Learned From the Exxon Valdez |
The scientists who monitored the oiled parts of Prince William Sound wanted to study the shoreline’s ecological recovery after an environmental disaster like the Exxon Valdez spill, and then use those lessons to better respond to future oil spills. Right now, their task is still incomplete. However, some of their findings have changed the way they think about cleaning up oil spills. Following are some examples of what they have learned:
More limited and measured use of aggressive cleanup methods, such as hot-water washing, would help to minimize the severe effects scientists have observed in plant and animal communities.
Using water to flush an oil-contaminated beach may also wash away fine-grained sediments, such as sand and nutrients, which small organisms need to successfully colonize. Sometimes, it takes years for the fine sediment to return.
Adult animals such as clams may survive in oil-contaminated beaches,
but juveniles don’t do as well.
Oil
that penetrates deeply into beaches can remain relatively fresh for
years and can later come back to the surface and affect nearby animals.
After the Exxon Valdez spill, beaches were reworked by heavy machinery to move heavily oiled upper intertidal sediments into
the middle intertidal
zone, where they could be washed by the surf and where the oil
could be collected in booms.
After such large-scale excavations, it can take many years for the
beach sediments to recover.
Rocky
rubble shores should be of high priority for protection and cleanup
because oil tends to penetrate deep and weather very
slowly in these habitats, prolonging the
harmful effects of the oil when it leaches out.
A brown sediment plume and sheens of refloated oil drift away from this oiled beach as it is cleaned by a team applying high-pressure, hot-water washing. Refloating of oil and the release of sediments are often unavoidable consequences of shoreline cleanup that can cause additional environmental harm. (Photo credit: OR&R, NOAA) | ||
|