The Coast of Pacific Beach Restaurant Walk
Coast Guard images of a sheen from 2010
A US Customs and Border Protection helicopter spotted a 27-mile-long bluish-green oil sheen southwest of Point Loma on June 29, the latest in a string of large-area spills observed off the coast of San Diego in the last 12 months.
The sheen was 1,000-feet wide, running east to west starting 15 miles from Imperial Beach, which, according to US Coast Guard Sector San Diego, indicates it was leaking from a boat either leaving or approaching San Diego. Ships are required to report spills immediately, but no ship operators have come forward in the case and the investigation has produced no leads, Lt .Anthony Baird of Sector San Diego's Incident Management Division tells CityBeat.
"We couldn’t really pinpoint anything that was close enough to the area at the time to directly tie it to the sheen," Baird says.
Last year, CityBeat reported on three other large spills, starting with a 15-mile sheen sighted off the coast of Imperial Beach in August. The next month, a 2-mile-by-quarter-mile sheen was documented 20 miles east of San Clemente Island followed a few days later by a 5-mile-by-half-mile sheen 33 miles west of Oceanside. The responsible parties were not caught.
With this latest case, the Coast Guard Cutter Sea Otter arrived on scene for initial observations and determined the color of the sheen was consistent with diesel fuel. No clean-up was deemed necessary after the National Oceanic and Atmospheric Administration determined the sheen would not make landfall. A Coast Guard helicopter sent out six hours later could not find the spill, which was presumed to have evaporated.
"Typically with diesel, oil response cleanup techniques are not always entirely effective," Baird says. "Typically diesel will evaporate over time and that usually is the most optimal method unless you have a concentration...but when it spreads out like that in a sheen there’s not a lot you can do to collect it."
Baird says it is possible that the spill was intentional. Ship operators responsible for sheens like this can face civil penalties and fines for discharging oil in a U.S. Naval waterway
It's difficult to gauge the environmental impact of sheens, since a single cup of diesel will spread out substantially over the surface of water.
“Oil is a hodgepodge, a Frankenstein with several hundred different compounds that can be in it,” San Diego Coastkeeper staff scientist Jen Kovecses told us last year. “If you’re a duck sitting in the middle of this sheen, it’s possible to get some of that oil on you. If you’re a fish, you might get some exposure of your gills, but it depends on the size of the sheen and how long that organism sits there.”
Here's a map of the largest sheens spotted near San Diego in the last year:
View Oil Sheens in a larger map
The sheen was 1,000-feet wide, running east to west starting 15 miles from Imperial Beach, which, according to US Coast Guard Sector San Diego, indicates it was leaking from a boat either leaving or approaching San Diego. Ships are required to report spills immediately, but no ship operators have come forward in the case and the investigation has produced no leads, Lt .Anthony Baird of Sector San Diego's Incident Management Division tells CityBeat.
"We couldn’t really pinpoint anything that was close enough to the area at the time to directly tie it to the sheen," Baird says.
Last year, CityBeat reported on three other large spills, starting with a 15-mile sheen sighted off the coast of Imperial Beach in August. The next month, a 2-mile-by-quarter-mile sheen was documented 20 miles east of San Clemente Island followed a few days later by a 5-mile-by-half-mile sheen 33 miles west of Oceanside. The responsible parties were not caught.
With this latest case, the Coast Guard Cutter Sea Otter arrived on scene for initial observations and determined the color of the sheen was consistent with diesel fuel. No clean-up was deemed necessary after the National Oceanic and Atmospheric Administration determined the sheen would not make landfall. A Coast Guard helicopter sent out six hours later could not find the spill, which was presumed to have evaporated.
"Typically with diesel, oil response cleanup techniques are not always entirely effective," Baird says. "Typically diesel will evaporate over time and that usually is the most optimal method unless you have a concentration...but when it spreads out like that in a sheen there’s not a lot you can do to collect it."
Baird says it is possible that the spill was intentional. Ship operators responsible for sheens like this can face civil penalties and fines for discharging oil in a U.S. Naval waterway
It's difficult to gauge the environmental impact of sheens, since a single cup of diesel will spread out substantially over the surface of water.
“Oil is a hodgepodge, a Frankenstein with several hundred different compounds that can be in it,” San Diego Coastkeeper staff scientist Jen Kovecses told us last year. “If you’re a duck sitting in the middle of this sheen, it’s possible to get some of that oil on you. If you’re a fish, you might get some exposure of your gills, but it depends on the size of the sheen and how long that organism sits there.”
Here's a map of the largest sheens spotted near San Diego in the last year:
View Oil Sheens in a larger map
