Oil and gas have been seeping from the ocean floor for thousands of years, and the Santa Barbara Channel is home to one of the largest seep fields in the world.
This fact has been misused by some powerful interests who would like to lift the offshore oil drilling ban. An industry-funded group called SOS (Stop Oil Seeps) California is advocating for increased oil drilling off Santa Barbara’s coast, claiming this will reduce natural oil seeps harmful to the environment.
Two weeks ago I wrote a column debunking some of the myths being used to support lifting the offshore drilling ban, including this one. Since the question about oil seeps has aroused local interest, here are additional details on the subject, examining two crucial questions: 1) Does natural oil seepage harm the environment? 2) If so, does offshore drilling help reduce the seepage?
So, how harmful are oil seeps to the environment? We know that seep vents release several gaseous and liquid hydrocarbons, and some are toxic. However, studies show that most of these harmful elements dissolve or biodegrade rapidly in the water before ever reaching the atmosphere, while others become part of the food chain. The parts that do make it to shore in the form of tar or pitch may be a nuisance, but have no significant effect on nearshore ecosystems, according to a definitive study published in the Journal of Geophysical Research. The harmful gases that do reach the surface contribute to only 5 percent of the smog in our county, according to the Santa Barbara County Air Pollution Control District. The burning of fossil fuels is a far more significant factor in air pollution.
A 2002 report by the county Energy Division concludes that there is no comparison between the harm caused by industry oil spills and natural oil seeps. The marine environment for the most part has adapted to the slow natural oil seepage that has been going on for thousands of years, and any damage to the environment is insignificant. However, when large, concentrated amounts of oil are spilled suddenly into the environment, the harm to marine life is devastating.
Altogether, research indicates the seeps are not a significant cause of air or water pollution in Santa Barbara County.
Given this reality, the question of whether oil drilling will reduce seeps may be a moot point. In any event, the research regarding this question is inconclusive. While one study indicates a decline of seepage near Platform Holly, there is insufficient evidence to support or refute the claim that oil drilling is actually the cause of reduced oil seepage.
Moreover, the reduction supposedly caused by oil drilling in one area could actually cause increased seepage in another area. A Venoco Environmental Impact Report explains how “with additional production from different formations, water injection will increase and could produce a net inflow of fluids into the Monterey formation (or other seep producing formations), which could produce an increase in seep activity.” (Section 4.1, p. 4.1-28)
A local geohydrologist agrees with that assessment: “During a major cleanup operation at Cape Canaveral (Fla.), the injection of steam into a contaminant source area spread the contaminated plume to areas that had previously been clean. As a result, cleanup estimates increased by more than five-fold. This exemplifies the fact that injection of materials to encourage movement and extraction of petroleum … is not always controllable.”
In the end, there’s no clear evidence that natural seepage does grave harm to the environment, or that drilling will reduce seeps rather than increasing seepage elsewhere. The argument that lifting the offshore drilling ban will cure natural oil seepage is itself a red herring.
One industry-wise critic responding to my last column agreed that the oil seep argument had no merit. “Was the SOS claim that drilling will stop seepage directed to a few specific fields, or all fields?” he wrote. “Because it’s a nonsensical claim. It has been shown to be the case in isolated instances. But the vast majority of oil fields have no seeps at all. And many fields that do have seeps are already being drilled. Anyone who knows the industry knows this … listen to authoritative voices, not extremists.”
An intelligent debate on lifting the ban on offshore oil drilling should not be sidetracked into a discussion about oil seeps. I hope this column helps put that argument to rest.
Deborah Brasket is executive director of the Santa Barbara County Action Network (SB CAN). She can be reached at 805.722.5094 or at email@example.com. This commentary originally appeared in the Santa Maria Times.