You’ve heard of the canary in the coalmine. Well, a species called the Gulf killifish might be the fish in the oil well.

Three years ago, the blowout at BP's Macondo well spewed more than five million barrels of oil into the Gulf of Mexico. Despite attempts to recover it, much of that oil made it into sediments. And new tests show that such oiled sediments are bad for Gulf fish. The research is in the journal Environmental Science and Technology.

The Gulf killifish maxes out at about 18 centimeters in length and is ubiquitous all along the U.S. south coast. That makes it a good subject for testing the spilled oil's toxicity.

When a consortium of researchers ran those tests, they found multiple negative effects. The oiled sediments were associated with delayed hatching of embryos, smaller newborns and heart defects. And fewer of the eggs hatched at all, even among those exposed to sediments collected a full year after the oil spill began. Adults captured in the wild showed an immune response to oil in their gills and livers.

These effects might be found in everything from other fish to the famous Gulf shrimp and oysters. We're just beginning to understand the full price of our oil addiction.

—David Biello

[The above text is a transcript of this podcast.]