Chemicals used to disperse Gulf of Mexico spill blamed for marine deaths and human illness
Hundreds of beached dolphin carcasses, shrimp with no eyes,
contaminated fish, ancient corals caked in oil and some seriously unwell
people are among the legacies that scientists are still uncovering in
the wake of BP's Deepwater Horizon spill.
This week it will be three years since the first of 4.9 billion
barrels of crude oil gushed into the Gulf of Mexico, in what is now
considered the largest marine oil spill in the history of the petroleum
industry. As the scale of the ecological disaster unfolds, BP is
appearing daily in a New Orleans federal court to battle over the extent
of compensation it owes to the region.
Infant dolphins were found
dead at six times average rates in January and February of 2013. More
than 650 dolphins have been found beached in the oil spill area since
the disaster began, which is more than four times the historical
average. Sea turtles were also affected, with more than 1,700 found
stranded between May 2010 and November 2012 – the last date for which
information is available. On average, the number stranded annually in
the region is 240.
Contact with oil may also have reduced the
number of juvenile bluefin tuna produced in 2010 by 20 per cent, with a
potential reduction in future populations of about 4 per cent.
Contamination of smaller fish also means that toxic chemicals could make
their way up the food chain after scientists found the spill had
affected the cellular function of killifish, a common bait fish at the
base of the food chain.
Deep sea coral, some of which is thousands
of years old, has been found coated in oil after the dispersed droplets
settled on the sea's bottom. A recent laboratory study found that the
mixture of oil and dispersant affected the ability of some coral species
to build new parts of a reef.
Doug Inkley, a senior scientist for
the US National Wildlife Federation and author of a report published
this week on wildlife affected by the spill, said: "These ongoing deaths
– particularly in an apex predator such as the dolphin – are a strong
indication that there is something amiss with the Gulf ecosystem."
Scientists
believe that the 1.8 million gallons of dispersant, sprayed as part of
the clean-up, have cemented the disaster's toxic effect on ocean life
and human health. The dispersant, called Corexit, caused what some
scientists have described as "a giant black snowstorm" of tiny oil
globules, which has been carried around the ocean in plumes and has now
settled on the sea floor. A study last November found the dispersant to
be 52 times more toxic than the oil itself.
Larry McKinney,
director of the Harte Research Institute for Gulf of Mexico Studies,
said: "Before we depend on dispersants to get rid of oil and get it out
of sight, we need to understand what it can do in the open ocean. We're
told to keep oil off the shore and away from estuaries, but we've not
dealt with something like this before, that's in the open ocean and gone
from top to bottom, affecting the whole water column."
Scientists
believe the addition of dispersants to the oil made it more easily
absorbed through the gills of fish and into the bloodstream. Dr William
Sawyer, a toxicologist, has studied concentrations of petroleum
hydrocarbon (PHC) in edible fish and shellfish in the region. Samples
before the spill had no measurable PHC in the tissue, whereas fish
tested in recent months show tissue concentrations as high as 10,000
parts per million, or 1 per cent of all tissue. He said: "The study
shows that the absorption [of the oil] was enhanced by the Corexit."
BP
says the dispersants it used are "government approved and safe when
used appropriately", and that extensive testing has shown seafood in the
Gulf states is safe to eat.
Louisiana State University's
Department of Oceanography and Coastal Sciences has found sea life in
the Gulf with lesions and deformities that it believes may be linked to
the use of dispersants. These include shrimp with no eyes and crabs with
no eyes or without claws. BP claims these abnormalities are "common in
marine life", had been seen in the region before, and are caused by
bacterial infections or parasites.
In a blow to the region's
tourism, tar balls continue to wash up along the affected coastline,
which now stretches from the beaches of Louisiana to Mississippi,
Alabama and Florida. Marco Kaltofen, a chemical engineer at the
Worcester Polytechnic Institute, said: "We have a reservoir of petroleum
and petroleum-contaminated sediment that lies just offshore of several
Gulf beaches. Every time we have a storm, all of a sudden you're getting
these tar balls washing up."
It is not just wildlife that
scientists believe has been affected. Michael Robichaux, a Louisiana
doctor, has documented 113 patients who he thinks were made ill by
exposure to chemicals associated with the spill. Their most common
symptoms include headaches, memory loss, fatigue, irritability, vertigo,
nausea, blurred vision and insomnia.
One of Dr Robichaux's
patients, Jorey Danos, 32, is a formerly healthy father of three. Since
working for BP on the clean-up, he says he has experienced serious ill
health, including severe abdominal and joint pain that has left him
walking with a cane. Several doctors, including a neurologist, have put
his condition down to the neurological impact of exposure to the
chemicals related to the spill.
Mr Danos said: "I worked 21 days
in one of the boats skimming the oil and we were sprayed directly with
Corexit from above on three occasions. My skin came out with bumps and
burning and I started having breathing problems. When a speedboat with
BP representatives came by I asked for a respirator but they said no,
because it would lead to bad media attention. Now I'm still dealing with
it three years later." BP said all workers were provided with safety
training and protective equipment and would have had the opportunity to
join a class action settlement.
Geoff Morrell, BP's head of US
communications, said: "No company has done more to respond to an
industrial accident than BP has in the US Gulf of Mexico."
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