Nearly a year after the Deepwater Horizon rig exploded in the Gulf of Mexico, the oil isn't as visible as it once was. It's not as easy to photograph, and the impacts are often further from human eyes. National TV is no longer broadcasting live cam footage of a gusher of oil in the depths of the ocean.
And so far only a handful of peer-reviewed scientific studies have been published on the spill. Some may seize on this as a sign the spill did not have a major impact on the Gulf's marine ecosystem -- but that would be a dangerous, and false, assumption.
A shortage of studies should not be interpreted as an absence of harm.
As this recent New York Times' piece by Leslie Kaufman put it:
What has emerged in studies so far is not a final tally of damage, but a new window on the complexities of the gulf, and the vulnerabilities and capacities of biological systems in the face of environmental insults... How the regional ecosystem has responded, its strengths and weaknesses, will keep scientists busy analyzing data for years.
Indeed, it will take years for scientists to interpret what the BP spill has done to marine and coastal life. In the wake of the Exxon Valdez disaster, for instance, ecological studies were not published until three years after the spill, while research on chronic harm took 10 years.
It's not over. Let me repeat: it's definitely not over. But why do we have to wait so long before we know the full impact?
First, most of the studies underway now fall are part of the Natural Resources Damage Assessment--the process the government uses to determine how much the responsible company must pay to restore the ecosystem to pre-spill conditions.
Because the government is assembling a legal case against BP, it keeps its scientific findings under wraps until the matter is settled or goes to court. This makes sense from a litigator's stand point, but it can confuse the public. It's easy to assume that if we don't see a lot of headlines about ecological damage, then there mustn't be any. When the government releases its evidence, we will likely get a very different picture.
Second, biological research takes time. Scientists have to study impacted species for at least one to two generations to assess whether oil has influenced survival, reproductive ability, and ultimately population dynamics (the short & long term impacts to the age and size of a species' population). Then they need to assemble data from many species in order to see what's happened to the entire ecosystem. It's a long process.
What we know now--one year after the blowout--will likely be the tip of the iceberg. The spill's initial trauma has settled and the media's cameras have gone home, but now we enter the chronic phase of the oil disaster.
By no means does that mean the spill is over. It'll be with us for years--decades, even. If we fail to recognize that reality, then BP wins. The Gulf--a shared resource belonging to the American public--will lose.
What We Know So Far
In just the past month, we've seen evidence that Deepwater Horizon oil continues to lurk in the Gulf. Oily sediment still rests on the ocean floor. Tar balls are still washing up on beaches. Oil that came ashore in coastal marshes is being buried, preventing it from degrading. Wildlife, like dolphins, continue to encounter the oil.
We know that approximately 170 million gallons of oil and 200,000 metric tons of methane gas entered the Gulf of Mexico through the broken well-head in approximately 5,000 feet of water. The government estimates that approximately 8 percent of this oil was recovered via burning and skimming and approximately 26 percent evaporated. The remaining 66 percent of the oil either washed up on the coast (1,053 miles of shoreline were oiled), adhered to particles and went to the sea floor, was degraded by bacteria, or formed tar mats that remain scattered and floating in the Gulf of Mexico. The proportions of each are not yet known.
Of the 170 million gallons, a large--though still unknown--proportion of the oil traveled to the surface of the water where it formed a massive galaxy of slicks. A smaller proportion of the oil remained below the surface of the sea and formed plumes at between 800m and 1300m where they traveled horizontally, slowly mixing with deep water. The methane gas, which completely dissolved in the deep sea, also traveled in these plumes and was eventually consumed by methane-eating bacteria. The oil was either consumed by bacteria or sent to the sea floor - and the proportions here are also still unknown.
But much of what scientists have been able to determine so far is just this 'chemistry story' - the fate of the oil and gases. This is just one piece of the scientific puzzle necessary to determine the full impacts. The majority of the biology - the impact to ocean and coastal life - for instance, has not yet been pieced together.
Again--that does not mean the impacts are not there. We now have the body counts from the acute phase: Approximately 6,000 birds, 600 turtles, and 115 dolphins and whales were found dead over the first six months alone. Though it's difficult to pin all those deaths on the oil precisely, those figures are terribly alarming (five times the normal rate for dolphins and whales). According to federal counts, this year the number of turtle and dolphin deaths is up. That suggests something's amiss in the water.
In fact, a recent study found that actual mortality of marine mammals during the spill could be 16 to more than 250 times higher than the carcass count indicates, since whales and dolphins tend to quickly sink when they die. Many of the affected species are endangered or have small Gulf populations, amplifying the spill's probable impacts in the years to come.
Some of What We Don't Know Is Troubling
The data available so far represent tiny pixels of information; we will need many, many more in order to see the full picture. We need to be patient and support the science and the process. Yet we also have to make sure the government is doing everything it can to research critical questions. For example:
- Did the dispersants work? Studies on government websites do not provide the answers. The early 'oil budget' provided by NOAA should not serve as the final word on this matter, since critical information was missing from this early analysis (e.g., the size distribution of oil droplets before and after the application of dispersants).
- Will the government monitor the long-term effects of the disaster? The central lesson from the Exxon Valdez is that spill impacts can be manifested for decades.
- Where has the oil still in the environment gone? How much oil remains underwater? What amount rests on the Gulf's deep and shallow seafloors? What quantity washed onto beaches and into marshes? How much oil is being buried? The government should support a full synthesis of existing government and academic data and conduct a more refined oil budget, such as the one performed following the Exxon Valdez oil spill.
These questions remain unanswered, but they must not remain unexamined. That's why it's critical that interest in oil spill research does not fade with the headlines - not with the ever growing demand for hard-to-get-to oil.
What's at stake is nothing less than the quality of the restoration effort, our ability to respond to future oil disasters, and the fate of Gulf Coast communities.