BP Deepwater Horizon Oil Spill Chemicals Could Cause Heart Attacks In Gulf Of Mexico Tuna
Crude oil spilled into the Gulf of Mexico during the BP Deepwater Horizon spill could cause heart attacks in tuna, according to new research published in the journal Science. In the study, researchers from Stanford University and the National Oceanic and Atmospheric Administration found that crude oil contains chemical components that can slow heart rates and cause irregular heartbeats in fish, leading to cardiac arrest. The research was conducted as part of the Natural Resource Damage Assessment, a federal process set up in the spill's aftermath to assess damage to natural resources and contain it.
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"We've known from NOAA research over the past two decades that crude oil is toxic to the developing hearts of fish embryos and larvae, but haven't understood precisely why," said study coauthor Nat Scholz of NOAA's Northwest Fisheries Science Center in Seattle, Wash. "These new findings more clearly define petroleum-derived chemical threats to fish and other species in coastal and ocean habitats, with implications that extend beyond oil spills to other sources of pollution such as land-based urban stormwater runoff."
In the study, researchers mixed crude oil samples from the Deepwater spill with water and applied it to the heart cells of bluefin and yellow fin tuna. In small doses, the solution disrupted the flow of molecules into and out of tuna heart membranes, which renders the heart unable to contract regularly. Because a version of this damaging crude oil hydrocarbon is also found in coal tar, air pollution and stormwater runoff, the problem could affect fish beyond oil spill areas.
Study coauthor Barbara Block of Stanford University said that this process of moving potassium and calcium into and out of heart cells, which is called "excitation-contraction coupling," is common to all vertebrates. "We have discovered that crude oil interferes with this vital signaling process essential for our heart cells to function properly."
BP was quick to criticize the study, which it called "scientifically inappropriate" for failing to take "real-world conditions" into account. "The paper provides no evidence to suggest a population-level impact on tuna or other fish species in the Gulf of Mexico," BP said in a statement. "Bathing isolated heart cells with oil concentrations is simply not comparable to the real-world conditions and exposures that existed in the Gulf for whole fish." BP added that live tuna in the ocean have defense mechanisms that heart cells in a petri dish do not, and that the oil concentrations used by the scientists were far higher than what is actually present in the Gulf."
BP added that "it is scientifically inappropriate to take data from in vitro laboratory tests on isolated tuna heart cells and use it to make unsupported predictions about effects on a variety of live marine species or humans in the Gulf-effects that no one has observed or measured in the field."
The Deepwater Horizon oil rig exploded approximately 40 miles off the coast of Louisiana on April 20, 2010. Eleven people died in the explosion, which discharged 4.9 million barrels of oil into the Gulf of Mexico and became the biggest oil spill in history. BP has paid out $4.25 billion in criminal and civil penalties so far. The spill has also been blamed for causing lung diseases in Gulf of Mexico dolphins.
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