Science > Environmental Issues

Mother of all gushers - BP Oil Disaster in Gulf of Mexico

<< < (158/158)

treesparrow:

--- Quote ---Baby Dolphin Die-Offs Continue in the Gulf



An unusually high number of dead dolphins - including stillborn and infant calves - have washed up along the Gulf of Mexico shores in the two years since the Deepwater Horizon oil rig exploded into flames, unleashing tens of thousands of barrels of oil into the ocean.

More than 100 dolphin strandings already this year add to a pattern of death and disease among the marine mammals. In a normal year before the spill, about 74 strandings would be reported in the area. That number has increased eightfold in the past two years. Since February 2010, more than 600 have been found on the shores between the Louisiana-Texas border and the western coast of Florida.

And many of these dolphins have serious health problems -- lung disease, liver problems and low blood sugar -- according to autopsies on the animals and other research.

Scientists suspect oil as a major culprit, but linking the spill definitively with the dolphin die-offs has been tricky. Decomposition causes tissue to decay, making the animals difficult to study.

"In all of the dolphin deaths... only 17 percent are stranded alive or stranded in fresh-dead conditions," said Jenny Litz, a research fishery biologist with the National Oceanic and Atmospheric Administration, who is studying the die-offs. Decomposition makes it much harder to study tissues during a necropsy (A necropsy is the animal equivalent of an autopsy).

There's another fact that complicates the picture. The number of deaths began to rise in March 2010, shortly before the spill. After the spill, the number continued to climb, and the period since represents the longest-lasting dolphin die-off in the Gulf of Mexico, at 25 consecutive months. But the increase just before the spill suggests that other factors may also play a role, such as ocean pollution, or a disease some animals tested positive for called brucellosis, a bacterial infection not typically associated with mass dolphin death. This complicates both investigation into the strandings as well as an impending litigation against BP, Litz said.

Still, it certainly appears that oil is at least partly to blame, Michael Jasny, Senior Policy Analyst at the Natural Resources Defense Council, said.

"It's circumstantial evidence, but it's still very, very strong," he said. "The highest number of dolphin strandings have occurred in areas hit hardest by exposure to BP oil."

Historically, dolphin strandings peak between February and May, which is prime calving season. Consider some of these numbers from before and after the spill:

The average number of infant dolphin deaths or stillborns before 2010 was about 14. In 2010, that number jumped to 29. The following year saw 86 dolphins that were either premature, stillborn or stranded infants. Now that it's peak calving season, that number is once again on the rise.

"It's really quite astonishing," said Jasny. "It suggests that something is deeply wrong with fetal or maternal health."

Toxic compounds ingested by dolphins in oil-contaminated water could contribute to the rise in stillbirths, he said.

"Dolphins live very high on the food chain," Jasny added. "Fish are eating smaller fish, and smaller fish are eating plankton. All of those toxins work their way through each of these organisms in the food chain. So it's a bioaccumulation in the tissues of the top-feeders--dolphins."

But Litz maintains that it's still too soon to tell just what effect oil might be having on dolphin babies in the Gulf, stressing that in most populations, there is a higher mortality rate around birth.

While much of the NOAA-led investigation under the Natural Resource Damage Assessment process is ongoing, scientists are studying the effects oil in the water can have on dolphins.

Randall Wells, director of the Sarasota Dolphin Research Program at Mote Marine Laboratory, compared sick or stranded dolphins in Barataria Bay, an area off the coast of Louisiana that was heavily affected by the oil spill, with a healthy population of bottlenose dolphins in Sarasota Bay, an oil-free area.

"Prior to this, there were studies that show dolphins probably can detect oil in the water," Wells said. "Under most circumstances, they mostly avoid it." But, he adds, that would happen only if the dolphins have had previous experience with oil in their environment. "Even if they can detect it, they might not have known to avoid it."

In addition to lung disease and liver problems, Wells and his team found that many of the dolphins were anemic and suffering from low blood sugar and low stress hormones.

He pointed to continuous pollution in the Gulf of Mexico, rather than just the BP oil spill in particular, as a contributing factor to the deteriorating health of these marine mammals.

The nation's track record with the environment and fragile coastlines needs to change, Jasny said: "There are clear lessons to be learned from what is happening in the Gulf. It is obscene that we are not learning them."

--- End quote ---

I know scientists have to be cautious before reaching any conclusions about what's causing an increase in the die off rate in such an event as this, but I do wish they would just sometimes bloody well call a spade, a spade.

treesparrow:
I suppose this discovery of contaminated migratory birds a long way from the gulf was inevitable and no big suprise really.



--- Quote ---Gulf oil spill pollutants found in pelicans migrating to Minnesota

By Dan Gunderson
Minnesota Public Radio

Pollutants from the British Petroleum oil spill in the Gulf of Mexico two years ago are showing up in Minnesota birds that migrate to the gulf.

Researchers for the state Department of Natural Resources have found evidence of petroleum compounds and the chemical used to clean up the oil in the eggs of pelicans nesting in Minnesota, Minnesota Public Radio reports.

Scientists are looking for pollutants on a western Minnesota lake that is home to the largest colony of American white pelicans in North America. About 34,000 adult pelicans will raise some 17,000 chicks this year on islands in Marsh Lake.

The area is a perfect place to look for oil spill effects. Most of the birds spend winters in the Gulf of Mexico, from Cuba to
Texas. Young pelicans spend a full year on the gulf before they start breeding.

Pollutants inside the eggs could be a big problem, said Mark Clark, an ecologist at North Dakota State University who studies pelican eggs. Clark is helping DNR researchers look for oil-related contaminants.

"Even if they're present in small amounts they may have a large impact on the development (of pelican chicks)," he said.

As Clark and researcher Jeff Dimatteo stepped from a boat onto the largest island, thousands of gulls that also nest there protested the intrusion.

The scientists stepped cautiously among the pelican, gull and cormorant nests that cover the ground.

"The first question is, 'Well, are the contaminants there?' and the next step
is, 'What do they do?' " Clark said.

Scientists are most concerned about polycyclic aromatic hydrocarbons known to cause cancer and birth defects in animals. The other contaminant they're testing for is Corexit, a dispersant used to break up oil slicks on the water that according to the U.S. Environmental Protection Agency contains cancer-causing chemicals and endocrine-disrupting compounds. Endocrine disruptors can disrupt the hormone balance and affect embryo development.

Clark has collected dozens of unhatched eggs to be tested for petroleum compounds and the chemical dispersant used to break up oil slicks.

Pelicans are big birds -- a bit larger than a Canada goose. They grudgingly fly off their nests at the researchers' approach, exposing eggs or recently hatched naked chicks.

The parents watch carefully from a distance as Dimatteo, a graduate student at North Dakota State University, locates chicks he had tagged earlier that he is tracking. After he measures and weighs them, the scientists quickly gather their data and leave. The birds grunt and grumble as they settle back on the nests.

If pelicans are bothered too much, they've been known to abandon colonies.

Clark said very little research has been done on how petroleum affects developing bird embryos. Scientists don't yet know how the effects might show up in newly hatched birds.

But he said tiny amounts of specialized hormones guide the chick's development in the egg, so there's a good chance adding pollutants to the eggs will increase the risk of damage to the embryos.

"Any contaminant that makes its way into the bird could be bad, but it could be especially bad if it gets into the egg because that's where the developing embryo and chick starts," Clark said. "And when things go wrong at that stage there's usually no recovery."

Researchers are a long way from understanding the potential effect of the oil spill pollutants as they have received only the first preliminary results of lab tests.

Petroleum compounds were present in 90 percent of the first batch of eggs tested. Nearly 80 percent of the eggs contained the chemical dispersant used in the gulf.

"This high percentage really surprised me," said Carroll Henderson, the DNR's Nongame Wildlife Program supervisor.

Henderson cautions that the results are still too preliminary to draw any conclusions as there are no tests of eggs before the spill to compare them to. But he said the results raise a lot of questions.

"I think it gives us a real heads-up here that we may have created a very vital study," he said. "I'm not aware of any other Northern states that are looking at the impact of the gulf oil spill on migratory birds."

Henderson said results are back on 30 of 220 eggs submitted to a lab in Connecticut. The DNR has no results yet on loon eggs or tissue samples from adult loons sent to the lab. Those lab tests will be completed over the next several months, and more samples will be submitted to the lab this summer.

The project is funded through 2014 by a $250,000 grant from the state Environment and Natural Resources Trust Fund, generated by the state lottery.

DNR officials are asking Minnesotans to notify them of any dead loons so researchers can test the remains.

Researchers will return to the pelican colony, monitoring the success of each year's hatch. They know very little about how petroleum might affect the young birds and it will likely take at least five years to find answers. But so far, there is only enough state money for three years of research.



--- End quote ---

http://www.twincities.com/localnews/ci_20644540/bp-oil-spill-chemicals-found-minnesota-birds

LQB:
Thanks for the update treesparrow   :)  - at least they spend time away from the Gulf.

Navigation

[0] Message Index

[*] Previous page