Was oil spill cause of dolphin deaths ? (Gulf of Mexico, USA)

In this March 24, 2014 photo, an oiled gull preens its feather at the Bolivar Flats Shorebird Sanctuary in Bolivar, Texas. Officials said Monday night that changing currents, winds and weather were pushing the oil not only further into the Gulf, but also southwest along Galveston Island, resulting in expanded oil recovery efforts. Traffic backed up on both sides of the Houston Ship Channel that was shut down for a third day Tuesday, after a barge spilled as much as 170,000 gallons of oil into environmentally sensitive waters along the Gulf of Mexico. Photo By Melissa Phillip/Houston Chronicle

April 4^th, 2014 (Harvey Rice). GALVESTON — Scientists are trying to determine whether an oil spill two weeks ago contributed to a higher-than-normal number of dolphin deaths.

At least 29 dead dolphins have been found in the Galveston area since a ship and barge collided two weeks ago, spilling nearly 168,000 gallons of thick oil into Galveston Bay.

The number brought the total for March to 47, above the average of 34 dolphin strandings for the month and triple last years’ total of 15, said Heidi Whitehead, state operations coordinator for the Texas Marine Mammal Stranding Network.

A high number of dead dolphins are typically found during what is known as the stranding season, from January through March, Whitehead said.

But the oil spill has caused so much concern that more resources and effort are being devoted to the investigation into the dolphin deaths, Whitehead said. Biologists from the National Oceanic and Atmospheric Administration are assisting the Stranding Network, she said.

“Even though we cannot definitely say that oil has caused this increase in the number of strandings, we can say there is concern and will be concern and that is why we are increasing our level of investigation,” Whitehead said.

Of those stranded, two have been confirmed to have oil on their bodies and two are being tested for possible oil, she said. It could take weeks or months to determine whether any dolphins ingested oil, Whitehead said.

Most of the dolphins were found in Galveston and Brazoria counties, but one was found in Harris County, she said. The most recent finds were Wednesday, when four were found. She said several also had been found on Matagorda Island, where oil drifted after being pushed out of Galveston Bay.

One possibility is that dolphins that otherwise would not have been found are being discovered because of the large number of people there. Whitehead said. Some 1,500 people are involved in cleanup operations and they are finding dolphin bodies in places never frequented by the public, she said.

Even if the oil does not kill the dolphins immediately, it could cause health problems for the mammals in the long run.

“Long-term chronic effects can also happen,” Whitehead said. “It’s gong to be something we are going to be investigating for a long time following this event.”

More oiled birds

Gibbons, the Audubon conservation director, said officials had expected the number of oiled birds to dwindle as time went on, but instead the numbers appear to be increasing. The number of affected species has climbed to 20, including the endangered Piping plover. Especially troubling are the numbers of marsh birds spotted with oil on them, indicating that oil has seeped into the environmentally sensitive marshland. So far, the Unified Command, which comprises agencies that responded to the spill, has not reported oil entering the marshland.

“I don’t know where it is in the marsh, but we are seeing some marsh birds that have been oiled,” Gibbons said. He said that determining how many birds had been oiled is difficult, but a single volunteer on Galveston Island counted 300. The Unified Command is capturing oiled birds and taking them to be cleaned at a rehabilitation facility in Bay City, but most of the birds cannot be caught.

So far 258 oiled birds have been recovered, only eight of them alive, said U.S. Coast Guard Petty Officer Steve Lehmann. Three were released Friday, he said.

Higgins said two dead Kemp’s ridleys had been found, one on Galveston Island and one on Matagorda Island, both very decomposed. Thirteen dead and five living green turtles were found stranded in the Galveston area.

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