STATE OF THE GULF Gulf resilient but scarred five years after oil spill
Five years after the BP well explosion, there is no single, conclusive answer to how the Gulf of Mexico is doing, but there are many questions. Here are some of them:
WHAT DO SCIENTISTS SAY?
To assess the health of the Gulf of Mexico, The Associated Press surveyed 26 marine scientists about two dozen aspects of the fragile ecosystem to see how this vital waterway has changed since before the April 2010 spill. On average, the researchers graded an 11 percent drop in the overall health of the Gulf.
The surveyed scientists on average said that before the spill, the Gulf was a 73 on a 0 to 100 scale. Now it’s a 65. In the survey, scientists report the biggest drops in rating the current health of oysters, dolphins, sea turtles, marshes and the seafloor.
WHAT HAPPENED TO DOLPHINS?
Common bottlenose dolphins have been dying at a record rate in northern parts of the Gulf of Mexico since the BP spill, according to NOAA and other scientists who have published studies on the figures. From 2002 to 2009, the Gulf averaged 63 dolphin deaths a year. That rose to 125 in the seven months after the spill in 2010 and 335 in all of 2011, averaging more than 200 a year since April 2010.
That’s the longest and largest dolphin die- off ever recorded in the Gulf. But the number of deaths has started to decline, said Stephanie Venn-Watson, a veterinary epidemiologist at the Marine Mammal Foundation and a lead author of studies on the dolphin mortality.
In its report on the Gulf five years after the spill, BP said necropsies of dolphins and “other information reveal there is no evidence to conclude that the Deepwater Horizon accident had an adverse impact on bottlenose dolphin populations.”
WHAT HAPPENED TO TURTLES?
The endangered Kemp’s Ridley sea turtle used to look like a success story for biologists. It was in deep trouble and on the endangered list, but a series of actions, such as the use of turtle excluder devices, had the population soaring and it was looking like the species soon would be upgraded to merely threatened, said Selina Saville Heppell, a professor at Oregon State University.
Then, after the spill, the number of nests dropped 40 percent in one year in 2010. “We had never seen a drop that dramatic in one year before,” Heppell said.
Th e population climbed in 2011 and 2012 but then fell again in 2013 and 2014, down to levels that haven’t been that low in nearly a decade, she said.
There is not enough data or research to blame the oil spill with scientific rigor, “but it’s a remarkable coincidence, isn’t it?” Heppell said. BP in its report said: “The changing nesting trends could be due to many factors including natural variability and record cold temperatures.”
WHAT HAPPENED TO FISH?
University of South Florida marine scientist Steve Murawski sees problems — tumors, lesions and oil traces in internal organs — in key fish such as red snapper, kingsnake eels and especially tilefish. Carcinogenic chemicals associated with oil appear to have gotten through the skin of these bottom-dwelling fish, he said.
“Their livers have fresh Macondo oil in them,” said Samantha Joye of the University of Georgia.
BP’s report said commercial catches for finfish “continue to exceed immediate prespill levels.”