What’s
that black stuff on my feet? Seep Oil? Natural? Whatever – what can it do to
me?
SOS
documented in our last blog how natural oil seeps can negatively impact the
wild creatures who live in and around them.
What about the human creatures?
As
we stated, the first thing we notice as beachgoers is the tar on our feet – but
how does that tar get from the seeps to our feet?
State
and federal agencies, as well as UCSB researchers, study this phenomenon on a
regular basis. Photos from the U.S.
Geological Survey (USGS 2013) and the California Department of Conservation can
help connect the dots (or tar-balls!).
Take this one, for instance ->
As the caption states, “This
natural oil seep, at the base of a sea cliff near Santa Barbara, covers the
beach sand with an impressive build-up of black asphaltum. This tar-like
substance is eroded by waves to form pesky tar-balls, which are carried by
longshore currents to other beaches, miles away.”
Our
studies support the hypothesis that natural oil seepage from sea floor vents
are responsible for the majority of tar-ball accumulation on Southern
California beaches. Oil fingerprinting provides the crucial tool to verify of
the origin of this deposited oil (USGS 2013).
Natural
crude-oil seeps are common in regions of petroleum-bearing formations. This
natural contamination may result in human exposures to crude oil and subsequent
associated health risks. Risks from natural contamination sources are often
referred to as background risks (Sullivan 2011).
However, researchers on human health impacts
use different terminology to refer to risks from spilled oil. Health risks associated with exposures
resulting from accidental releases of chemicals into the environment are
referred to as additional or incremental risks (Sullivan 2011). Why should
there be a difference in terminology if the oil itself is the same crude?
We certainly share the
tar-ball experience with those past inhabitants of our coast. A recent Edhat
posting by Paul Costales was entitled “Tar: A Local Beach Tradition” and
highlighted what surfers go through when trying to find that perfect wave.
While writing about the lack of waves, he added that “… as the flat days
add up to weeks, our natural tar seeps compound our frustration too. As if
having a flat surf session isn't bad enough, you also have to get covered in
tar and spend a lot of time getting it off. Other ocean-goers are taking some
big hits too. Just last Friday a friend was swimming at Goleta Beach and was
covered in more tar then he's ever been covered in from oceangoing along our
local coast. Goleta Beach isn't typically considered one of the really tarry
beaches around here either. The tarriest beaches, not surprisingly, have some
tarry names, Tar Pits and Coal Oil Point (Sands and Deveraux) being the most
popular tar prone surf beaches in these parts.” http://www.edhat.com/site/tidbit.cfm?id=2603
So
tar-balls on the beach are definitely a conversation topic for surfers. Do they
also encounter oil in the water while surfing?
As
a UCSB Sophomore, Joey Krueger was interviewed for an article in the Santa
Barbara News-Press (Allison 2008). The mechanical engineering student and
surfer was quoted as saying “It’s pretty bad out here. When I go out surfing
for 1 hour I can literally feel the tar and oil in the back of my throat. I
actually get a sore throat if I’ve been surfing too long."
While
we don’t ingest oil while we’re in the water, at least not in the quantities
that marine mammals and birds do, it can get on our skin - and people who spend
time in the water definitely start to feel similar impacts to those creatures.
We
also inhale the fumes.Inhalation is the primary route of exposure for
the VOCs (White 2011). One of these VOCs is methane. The natural gas and oil seeps
beneath the Santa Barbara Channel cause gas to escape from the ocean floor and
float to the surface like carbonated soda bubbles, releasing methane, a potent
greenhouse gas, into the atmosphere.
Santa
Barbara County’s air quality has historically violated both state and federal
ozone standards. According to the county’s 2007 Clean Air Plan, offshore
natural gas and oil seeps is a major source of the county’s air pollution and
responsible for putting more than 22 tons of reactive organic gases into Santa
Barbara’s air every day. By comparison, all of the motor vehicle trips in Santa
Barbara County produce 18 tons of hydrocarbons each day. However the 2010 update of the Clean Air Plan
evaluates only human-generated sources of air pollution. Is the evaluation of
air quality complete without acknowledging the emissions from natural
seeps?
Mr. Costales
also wrote about the impact of Venoco’s activities near Coal Oil Point. “It is said that our local offshore drilling
has reduced pressure on the oil and gas fields allowing the natural seeps to
slow down. Local oil operator Venoco, has several "tents" they keep
out over some of the offshore seeps. They collect oil and gas bubbling up from
the ocean floor and pipe it to their onshore facility. It seems oil companies get
a bad rap from a lot of folks, but in this Venoco should be thanked for
collecting all of that junk that is going to end up on our beaches and turning
it into something we heat our homes with.”
Why should we continue to be impacted by the oil
seeps when there is a Sole-ution?
References
Allison, B. 2008.
What About Our Oil? Santa Barbara
News-Press. August 28, 2008.
Costales,
P. 2013
SBAPCD 2011
Sullivan, M. 1991.
Evaluation of Environmental and Human Health Risk from Crude-Oil
Contamination. Journal of Petroleum
Technology, Volume 43. Number 1. Society of Petroleum Engineers.
USGS 2013.
White, L. 2011
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