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• BP spill ‘not as bad as Exxon Valdez’

Scientists judge the overall health of the Gulf of Mexico as nearly back to normal one year after the BP oil spill, but with glaring blemishes that restrain their optimism about nature’s resilience.

More than 36 scientists grade the Gulf’s big picture health a 68 on average, using a 1-to-100 scale.

What’s remarkable is that that’s just a few points below the 71 the same researchers gave last year when asked what grade they would give the ecosystem before the spill.

And it’s an improvement from the 65 given in October.

At the same time, scientists are worried. They cite significant declines in key health indicators such as the sea floor, dolphins and oysters. In interviews, dozens of Gulf experts emphasised their concerns. They pointed to the mysterious deaths of hundreds of young dolphins and turtles, strangely stained crabs and dead patches on the sea floor.

Just as it was before the April 20 accident when the Deepwater Horizon oil rig exploded, ultimately spewing millions of litres of oil, the Gulf continues to be a place of contradictions.

The surface looks as if nothing ever happened while potentially big problems are hidden deep below the surface, in hard-to-get-to marshes and in the slow-moving food web.

Some may not be known for years.

“When considering the entire Gulf of Mexico, I think the natural restoration of the Gulf is back to close to where it was before the spill,” said Wes Tunnell at Texas A&M University. He says the Gulf’s overall health before the spill was a 70; he gives it a 69 now.

If the pre-spill grade isn’t impressive, it’s because the Gulf has long been an environmental victim – oil from drilling and natural seepage, overfishing, hurricanes and a huge oxygen-depleted dead zone thanks to the absorption of 40 percent of the US’s farm and urban run-off from the Mississippi River.

Today, a dozen scientists give the Gulf as good a grade as they did before the spill. One of those is Louisiana State University (LSU) professor Ed Overton, a veteran of oil spills.

“I walked a half-mile down the beach and there wasn’t a tar ball in sight. It was as pretty as I’ve ever seen it,” Overton said.

While that sounds good, the average grades for the sea floor plunged from 68 pre-spill to a failing grade of 57. Dolphins initially seemed to be okay, but as more carcasses than usual kept washing up – almost 300 since the spill – the grade fell to 66, compared to a pre-spill 75. Oysters, always under siege, dropped 10 points, crabs dropped six points. And the overall food web slid from 70 before the spill to 64.

“Everything may be fine in some places, but definitely not fine everywhere,” said University of Georgia researcher Samantha Joye.

She found dead patches of oiled sea bottom in expeditions near the bust well. “The oil isn’t gone; it’s just not where we can see it.”

Joye said before the oil spill she would have given the sea floor an “A” grade of 90. Now she gives it a 30.

Joye says much of the invisible oil in the water and on the sea bottom has been chemically fingerprinted and traced to the BP spill. She also has pictures of oil-choked bottom-dwelling creatures like crabs and brittle stars – starfish-like creatures that are normally bright orange but are pale and dead.

This is hidden from view.

Eugene Turner, an LSU wetlands scientist, has looked at marshes in Louisiana’s Barataria basin, and found oil buried in the mud and sand. “You can’t smell it. You can’t see it. It’s not this big black scum out there, but it’s there,” Turner said.

The oil is obvious only in a couple of places – Bay Jimmy is the worst-hit. A crust of oil still lines miles of the outer fringe of marsh in the bay.

Despite the picture on the surface, Dana Wetzel, at the Mote Marine Laboratory in Florida, says: “Anyone who says the Gulf is fine is being precipitous… It’s out-of-sight, out-of-mind, but in my humble opinion this is not over.”

While BP money has flowed for immediate clean-up and compensation, the bigger bill for environmental damage and federal penalties is still being calculated.

The federal government is collecting data on that, but much is kept from outside scientists.

Trying to quantify the scale of the injury to the Gulf ecosystem “is absolutely the right question”, said Robert Haddad, who heads the scientific process for the National Oceanic and Atmospheric Administration (NOAA). “One of the outcomes from the Exxon Valdez was that they tried to estimate the damage too quickly.”

The spill itself lasted nearly three months.

NOAA chief Jane Lubchenco told reporters in February that “it’s not a contradiction to say that although most of the oil is gone, there still remains oil out there”.

A year later, scientists are starting to see signs – and they are far from conclusive – of possible long-term problems.

Florida State University oceanographer Ian MacDonald warned his fellow scientists to be on the watch for deaths of big marine mammals. That was in October.

Since January, 155 young or foetal dolphins and small whales have washed up on Gulf beaches – more than four times the typical number – according to NOAA.

A new study estimates that for every dead dolphin that washes ashore there are 50 dolphins that are never found..

Blair Mase, NOAA’s marine mammal stranding co-ordinator, says dolphin deaths began to rise in February, 2010 – before the BP spill.

Fifteen of this year’s dead dolphins had oil on them, and NOAA chemically linked six of those to the BP well.

And it’s not just dolphins that are dying. NOAA reports in the first few months of this year, 141 endangered sea turtles were stranded – a higher than normal number. On top of that, Monty Graham, a researcher at the Dauphin Island Sea Lab in Alabama, noticed fewer jellyfish last year.

At Tulane University, scientist Caroline Taylor is investigating strange orange droplets inside crab larvae. Her team have taken samples from thousands of crabs, but they have not begun to analyse the abnormalities.

Jessica Henkel, a Tulane population ecologist, is spending long days rigging up nets to catch birds for tests.

“It’s much easier to see a dead pelican on the beach” than it is to see more chronic population-wide effects, she says.

Craig Matkin, a marine mammals biologist at the North Gulf Oceanic Society in Alaska, says: “There’s a real tendency to do this out-of-sight, out-of-mind thing until someone shows you that it’s not the truth. It doesn’t go away. There are going to be effects down the line.”

Larry McKinney, who heads a Gulf research centre at Texas A&M University in Corpus Christi, has days when he’s confident in the Gulf’s resilience and days when he’s pessimistic.

Somehow he can agree with both Overton and Joye.

He says the trouble is that there’s not enough information to get a complete picture. – Sapa-AP