Page 560 - Environment: The Science Behind the Stories

the Amoco Cadiz oil spill in France SHORELINES WATER COLUMN AND SEDIMENTS
in 1978 had found that Corexit 9500 • Air and ground surveys • Water quality surveys
appeared more toxic to marine life • Habitat assessment • Sediment sampling
than the oil itself. BP threw an unprec- • Measurements of • Transect surveys to detect oil
subsurface oil
• Oil plume modeling
edented amount of the chemical at
the Deepwater Horizon spill, injecting AQUATIC VEGETATION HUMAN USE
a great deal directly into the path of • Air and coastal surveys • Air and ground surveys
the oil at the wellhead. This caused
the oil to dissociate into trillions of tiny
droplets that dispersed across large
regions. Many scientists worried that
this expanded the oil’s reach, affecting Wellhead
more plankton, larvae, and fish.
Impacts of the oil on birds, sea
turtles, and marine mammals were
easier to assess. Officially confirmed
deaths numbered 6104 birds, 605 tur-
tles, and 97 mammals—and hundreds
more animals were cleaned and saved
by wildlife rescue teams—but a much FISH, SHELLFISH, AND CORALS BIRDS, TURTLES, MARINE MAMMALS
larger, unknown, number succumbed • Population monitoring of adults and larvae • Air, land, and boat surveys
to the oil. What impacts this mortality • Surveys of food supply (plankton • Radiotelemetry, satellite tagging,
may have on populations in coming and invertebrates) and acoustic monitoring
• Tissue collection and sediment sampling
• Tissue sampling
years is unclear. (After the Exxon Valdez • Testing for contaminants • Habitat assessment
spill in Alaska in 1989, populations of
some species rebounded, but popula- FIGURE 2 Thousands of researchers continue to help assess damage to natural resources
tions of others have never come back.) from the Deepwater Horizon oil spill. They are surveying habitats, collecting samples and
Researchers are following the move- testing them in the lab, tracking wildlife, monitoring populations, and more.
ments of marine animals in the Gulf
with radio transmitters to try to learn
what effects the oil may have had. work. The government tested fish and spill. The Gulf’s warm waters and sunny
As images of oil-coated marshes shellfish for contamination and reopened climate speed the natural breakdown of
saturated the media, researchers fishing once they were found to be safe, oil. In hot sunlight, volatile components
worried that widespread death of but consumers balked at buying Gulf of oil evaporate from the surface and
marsh grass would leave the shoreline seafood. Beach tourism remained low all degrade in the water, so that fewer toxic
vulnerable to severe erosion by waves. summer as visitors avoided the region. compounds such as benzene, naphtha-
Louisiana has already lost many coastal Together, losses in fishing and tourism lene, and toluene reach marine life. CHAPTER 19 • FOSSIL FUELS, THEIR IMPA CT S, AND ENERGY CONSERVATI ON
wetlands to subsidence, dredging, sea totaled billions of dollars. In addition, bacteria that consume
level rise, and silt capture by dams on Scientists expect some impacts hydrocarbons thrive in the Gulf because
the Mississippi River (pp. 407–408). from the Gulf spill to be long-lasting. some oil has always seeped naturally
Fortunately, researchers found that oil Oil from the similar Ixtoc blowout off from the seafloor and because leakage
did not penetrate to the roots of most Mexico’s coast in 1979 still lies in from platforms, tankers, and pipelines
plants and that oiled grasses were sediments near dead coral reefs, and is common. These microbes give the
sending up new growth. Indeed, Louisi- fishermen there say it took 15–20 years region a natural self-cleaning capacity.
ana State University researcher Eugene for catches to return to normal. After Researchers continue to conduct a
Turner said that loss of marshland the Amoco Cadiz spill, it took seven wide range of scientific studies (FIGURE 2).
from the oil “pales in comparison” with years for oysters and other marine spe- A consortium of federal and state agencies
marshland lost each year due to other cies to recover. In Alaska, oil from the is coordinating research and restoration
factors. Exxon Valdez spill remains embedded efforts in the largest ever Natural Resource
The ecological impacts of the spill in beach sand today. Damage Assessment, a process man-
had measurable impacts on people. The However, many researchers are dated under the Oil Pollution Act of 1990.
region’s mighty fisheries were shut down, hopeful about the Gulf of Mexico’s Answers to questions will come in gradu-
forcing thousands of fishermen out of recovery from the Deepwater Horizon ally as long-term impacts become clear.
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