For many Santa Barbara, California, residents, last week's oil spill stirred up painful memories. In 1969, this region was the site of what is still one of the largest spills in United States history, when an estimated 3.3 million gallons of oil poured from a ruptured well located five miles offshore, in nearby Summerland. The spill is often credited with catalyzing the U.S. environmental movement.
In the wake of that 1969 spill, researchers published dozens of scientific reports, tallying the oil's effects on the environment and on the people of Santa Barbara. We're gathering the results of those studies here, as well as what lessons we can learn from them for the recent spill that's still staining Santa Barbara's water and shoreline.
THE EFFECTS OF THE 1969 SPILL ON ANIMAL LIFE
At first, it was hard to say how many animals the 1969 spill affected. Animals move around and avoid humans—and sometimes it can be hard to tell whether they've died from exposure to oil, or for other reasons. Within a few years, however, scientists came up with precise—and devastating—numbers.
One pair of biologists from the University of California-Santa Barbara estimated that the spill killed 9,000 birds, more than 14 tons of surfgrass, and nine million barnacles. (The official California Department of Fish and Game count is about 3,700 birds, which is the number of birds they found and tried to treat, but scientists think that's an underestimate because many dead birds don't come ashore.) Along certain stretches of the coast, all the barnacles, mussels, limpets, and periwinkles died, a team of Caltech engineers reported.
Even animals that don't die may still feel an oil spill's effects. After the 1969 disaster, three of the six mussel and barnacle species that biologist Dale Straughan studied reproduced less than they had prior to the spill. New barnacles were also less likely to settle on rocks with dried oil on them than on clean rocks, meaning they were less likely to come live on oiled beaches altogether.
• How Big Is a Spill? It Depends on Who's Measuring: Estimates of the size of the 1969 Santa Barbara spill varied widely—just like estimates of oil spill sizes do today.
While cleaning its spilled oil, the Union Oil Company of California blasted rocky beaches and pier areas with water, steam, or sand. One contractor used a slurry of talc and naphtha to dissolve the oil. Nobody conducted detailed studies on the effects of these procedures on animals living on the rocks, but "it is reasonable to assume that the procedures used to remove dried oil from solid substrates will also remove and possibly kill attached organisms," UCSB biologists reported. One team of researchers estimated that steam cleaning kills 60 percent of the mussels inhabiting the area.
Because the current spill is much smaller than the 1969 one—authorities say it released 105,000 gallons, less than a quarter of which reached the ocean—these drastic numbers likely won't apply to the current spill. But we may see many of the same species affected: birds; small, sessile animals living on rocky shorelines; and plants living in the water, which are important to cleaning the water and protecting small areas from the surf.
There's another lesson to learn here, too. Many of these reports were published months or even a few years after the spill occurred. It takes time to tally a disaster's impact on wildlife. Some effects, such as reduced reproduction rates, aren't apparent right away. Don't expect scientists to be able to make reliable estimates of the animal impact of the current spill very soon, says Peter Alagona, a historian of California environmental politics at UCSB.
"A lot of claims can get thrown around that you can't make without data. You may hear there's been minimal damage to wildlife, or a lot of damage," Alagona says. Historically, such statements haven't panned out, he says, until researchers get exact numbers in from the field. People initially reported that elephant seals, sea lions, and whales died because of the 1969 spill, but researchers later found those animals to have likely died from other causes. Conversely, it wasn’t until this year that a team of scientists was finally able to gather enough evidence to demonstrate that the Deepwater Horizon spill in 2010 killed bottlenose dolphins by injuring their internal organs.
This delay in the science creates a catch-22. By the time an accurate animal toll comes in, the news cycle may have moved on and the public might not care about the spill's wild victims anymore. This is a phenomenon that's well known to social scientists. This time, however, we've got some historical numbers to mull over while we wait for the science to come in—figures that demonstrate just how important a little oil can be to a lot of wildlife.