From either an ecological or public relations perspective, the Galveston Bay oil spill in March that released 168,000 gallons of thick, residual oil had the makings of a disaster.
The peak spring migration was nearing and birds returning from their Latin American wintering grounds had begun crowding Texas estuaries. A smaller sort of migration was also underway as droves of baby shrimp were returning from the Gulf to feed and grow in the shelter of the bays.
It was also one day before the 25-year anniversary of the infamous Exxon Valdez oil spill that slicked over 1,300 miles of Alaskan coastline and punished fisheries to the tune of hundreds of millions of dollars, a fact not lost on many journalists who tucked into the story.
But how bad was it, actually?
During the first week of the spill, responders were holding their breath, at a loss to say how bad the situation was. Much depended on how the oil and currents mixed. Would the oil float on the surface or would it sink, potentially smothering valuable oyster beds below? Would it disperse in deeper waters or would currents push it back into the ecologically-rich estuaries where the difficulties of remediation multiply? What about the critically endangered whooping cranes that overwinter in San Antonio Bay? How would they be impacted if the slick reached around Matagorda Island?
While some uncertainty exists about how long the spill will pose a risk to aquatic life along the coast, two weeks later it appears we’ve dodged each of these lethal bullets.
“I don’t see this as a big toxic event,” said Edward Overton, professor emeritus in the Department of Environmental Sciences at Louisiana State University. “Heavy oils, even though they persist, they don’t really have the big environmental impacts of light oils that can spread, can dissolve, can evaporate.”
Researchers appear to be backing up that assessment, though Overton’s opinion on the hazards of residual fuel oil isn’t shared by all.
Before the consumption of much of the world’s easily accessible oil led to extreme extraction practices—fracking, ultra-deepwater drilling, or the strip-mining of the Canadian tar sands—residual fuel oils (“bunker” fuel when burned to power ships) represented the literal bottom of the barrel. These refining dregs, once considered part of the petroleum industry’s waste stream, are too thick to be usable as a transportation fuel except by burning in massive engines, such as those found on large sea-going vessels.
Residual fuel oil, this most-polluting stream of traditional petroleum refining, contains a high concentration of heavy metals and polycyclic aromatic hydrocarbons (PAHs) and represents a serious hazard, especially when burned. In the water, residual fuel oil tends to clump together and float on top of the water. The fuel is a potentially lethal navigational hazard for marine wildlife until it is cleaned up or broken down in the environment, but its tendency to clump can also make it easier to clean up than lighter fuels.
So far, the impact on marine wildlife of the Texas City spill has been “minor,” according to Texas A&M professor Randall Davis, an expert in marine mammals and birds who assisted in the emergency response to the Exxon Valdez spill years ago.
“The good news is I’ve only heard of 50 or so birds picked up for rehabilitation,” he said. “However, this heavy oil may, under certain circumstances, sink. If it does it has the potential of smothering marine animals that live on the seafloor. And there is the possibility of bottom-living commercial shrimp coming into contact with this oil.”
Last week, Overton said the slick appeared to be mostly staying afloat. However, U.S. Coast Guard officials said on Friday that all water-based operations have ceased since there is no longer observable oil on the water thanks to skimming operations, evaporation, natural dispersion and collection on the shoreline.
The spill occurred shortly after the captain of the Miss Susan tugboat, pulling an oil tank barge loaded with roughly a million gallons of residual fuel oil, started across the Houston Ship Channel. From the south, a towering 585-foot-long bulk carrier flying a Liberian flag was bearing down.
Less than a mile apart, Miss Susan’s captain first radioed the Summer Wind to ask how things looked.
“Well, if you keep on going, I’m gonna get you,” the Summer Wind captain responded a couple minutes before impact, according to recorded radio traffic released to KPRC Houston.
Last-minute evasive maneuvers weren’t enough to keep the Summer Wind from cutting a gash into the oil barge’s No. 2 starboard tank.
The oil has since drifted into the Gulf and washed ashore further down the coast, including on Matagorda Island. About 335 birds have been recovered by the multi-agency response teams, according to U.S. Coast Guard officials. All but 10 of those, which are now being rehabilitated, were found dead. Additionally, more than 20 dolphins and several turtles have been recovered, according to a release by the National Oceanic and Atmospheric Administration. Most, however, have not been visibly oiled and necropsies are being performed to determine the cause of death.
While shorebirds remain at risk, other fowl are being somewhat sheltered by coastal geography as tarballs from the spill continue to wash up on Texas beaches, said Iliana Peña, director of conservation for Audubon Texas.
“Thankfully the barrier islands are doing what they’re supposed to do, they’re protecting our bays where our colonial water birds, the pelicans, herons, skimmers and terns are nesting,” Peña said.
A U.S. Coast Guard fact sheet on the spill links the fumes from the oil to nausea, headaches, breathing difficulty, “loss of muscular coordination, blurred vision, asphyxia caused by lack of oxygen, and convulsions. … Respiratory and dermatological upsets, depression of the central nervous system.”
Unlike lighter forms of fuel, however, only a minor amount of residual fuel oil will evaporate to pose a respiratory risk. “Since the irritants present can be inhaled, dolphins and other marine mammals are especially vulnerable every time they surface to breath near or within a spill zone,” Julia O’Hern, an oceanography research assistant at Texas A&M, wrote the Observer.
Environmental advocacy organization Friends of the Earth argued in 2008 that the low evaporation rate was a bad thing. Because so little of the fuel evaporates, the slicks persist in the marine environment longer, “wreaking more extensive harm on wildlife and marine resources,” the group wrote in its call for a ban on bunker fuels in the U.S.
U.S. and Canadian governments agreed with Friends of the Earth at least on the issue of air quality. In 2012, the two nations banned the combustion of high-sulfur bunker fuels within 200 nautical miles of the east, west and southern coasts. That effectively ended the burning of the fuel along the coast, but not its production, transport or sale.
A spokesperson for Kirby Inland Marine, the Houston-based company responsible for the tug and oil barge involved in the accident, would not comment on the origin or destination of the fuel—or say how much the company has been billed to date.
The collision and spill weren’t a first for either of the companies involved. Kirby has been cited in at least 255 spills since 2000, the year the Texas General Land Office began performing marine enforcement. While most involved less than a gallon of oil and fines under $1,000, two spills—44,100 gallons released into Galveston Bay in 2000 and 8,400 gallons dumped into the Corpus Christi Ship Channel in 2012—resulted in more than $40,000 in fines, according to data provided to the Observer by the GLO. Summer Wind is operated by a Greek company on probation for discharging bilge water “and other oily wastes” into the ocean—and then falsifying records to cover it up—in 2011.
But before we shut the door on long-term ecological damages coming back to haunt us from the Texas “Y,” it’s worth considering a report released just last month demonstrating the staying power of oil spills. By recreating the conditions of the world’s largest accidental spill—BP’s 2010 fiery Deepwater Horizon—researchers concluded that large predatory fish (in this case, bluefin tuna, yellowfin tuna, and an amberjack) would have suffered serious heart defects from exposure to PAHs sure to limit their ability to develop into adulthood.
Similar findings were observed following the Exxon Valdez spill, which Davis said involved a particularly nasty form of crude far higher in PAHs than the bunker fuels scouting Texas beach locations.
Obviously, both spills were much, much larger than last month’s spill, with a much greater toxic load. Potential long-term impacts of the “Y” will likely be minimal, according to scientists.
Antonietta Quigg, a marine biology professor at Texas A&M University at Galveston, told the Galveston County Daily News that despite some cycling of the toxins up the food web through planktons, life in the Gulf should return to “something close to normality” within weeks.Overton expects that what toxins remain after that will stay locked up in tarballs, remaining mostly outside of the food web and only breaking down gradually over a long period of time.
For those who may be tempted, the Texas Department of State Health Services issued an advisory on the fifth day of the spill, suggesting any seafood with a “hydrocarbon taste or smell” be chucked out.
You know, should you need the extra encouragement.