The white pelicans developing inside eggs on Minnesota’s Marsh Lake islands weren’t around two years ago when the catastrophic BP oil spill occurred, but they may be marked by the disaster anyway.
Most of the tens of thousands of white pelicans that nest on the lake islands winter in the Gulf of Mexico, so scientists are investigating the spill’s effect on these migratory birds. Their early findings are alarming. Preliminary evidence shows that the vast majority of the small sample of eggs tested so far contain petroleum compounds and Corexit (the chemical dispersant used to break up oil slicks).
Scientists from the state Department of Natural Resources and North Dakota State University have collected 220 eggs to date, and lab results are back on 30 of those, Dan Gunderson reports for Minnesota Public Radio. In the first batch, petroleum compounds were detected in 90 percent of the eggs, and Corexit was present in almost 80 percent.
As Gunderson explains, scientists are primarily worried about polycyclic aromatic hydrocarbons, which have been shown to cause developmental abnormalities in birds. As for Corexit, studies show that some of its ingredients cause reproductive problems in wildlife (click here for a break down of the substances that make up Corexit).
From the story:
|[Mark Clark, an ecologist at North Dakota State University who studies pelican eggs and is working with the DNR] 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 bird.
But he said tiny amounts of specialized hormones guide the chicks 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.
Still, as the National Wildlife Federation’s senior scientist Doug Inkley put it on the organization’s blog, “While many more tests are needed, this is not good news. Instead of quickly breaking down, oil and dispersant could be entering the food chain, persisting and being passed on to the next generation.”
Read (or listen to) the full story at minnesota.publicradio.org.