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Countermeasures/ Mitigation

In the initial stages of the spill, an estimated 30,000 barrels of oil per day
were flowing from the well.  In July 1979 the pumping of mud into the well
reduced the flow to 20,000 barrels per day, and early in August the pumping of
nearly 100,000 steel, iron, and lead balls into the well reduced the flow to
10,000 barrels per day.  Mexican authorities also drilled two relief wells into
the main well to lower the pressure of the blowout.  PEMEX claimed that half of
the released oil burned when it reached the surface, a third of it evaporated,
and the rest was contained or dispersed.

PEMEX contracted Conair Aviation to spray the chemical dispersant Corexit 9527
on the oil.  A total of 493 aerial missions were flown, treating 1,100 square
miles of oil slick.  Dispersants were not used in the U.S. area of the spill
because of the dispersant's inability to treat weathered oil.  Eventually the
OSC requested that Mexico stop using dispersants north of 25°N.

In Texas, an emphasis was placed on coastal countermeasures protecting the bays
and lagoons formed by the Barrier Islands.  Impacts of oil to the Barrier Island
beaches were ranked as second in importance to protecting inlets to the bays and
lagoons.  This was done with the placement of skimmers and booms.  Efforts were
concentrated on the Brazos-Santiago Pass, Port Mansfield Channel, Aransas Pass,
and Cedar Bayou (which during the course of the spill was sealed with sand). 
Economically and environmentally sensitive barrier island beaches were cleaned
daily.  Laborers used rakes and shovels to clean beaches rather than heavier
equipment which removed too much sand.  Ultimately, 71,500 barrels of oil
impacted 162 miles of U.S. beaches, and over 10,000 cubic yards of oiled
material were removed.  

On August 8, the United States Fish and Wildlife Service (USFWS) began training
volunteers for the handling of oiled birds and implemented beach patrols on
South Padre Island.  Bird cleaning stations were set up by the USFWS on Mustang
and South Padre Islands.  An overall decrease in bird population densities due
to movement from their regular habitats along the oiled shoreline may account
for the fact that only a few dead, oiled birds were ever found.  After the
beaches were cleaned, population densities increased, but not to expected
levels.  Contamination of food supplies caused many birds to leave their
habitats for the duration of the spill.  One thousand four hundred twenty one
birds were recovered with oiled feathers or feet.  The species suffering the
most incidents of oiling were the Royal Terns,  Blue-faced Boobies, Sanderlings,
Willets, Piping Plovers, Black-bellied Plovers, and Snowy Plovers suffered
oiling to their feathers while Great Blue Herons, Black-Crowned Night Herons,
Noddy Terns, Cattle Egrets and Snowy Egrets had tarred feet.