May 28, 2010 5:45 AM
Alicia Duplessis Jasmin
Louisiana’s coastal birds face an uncertain future as oil continues to seep into the marshes where they live. Tulane University ecologist and conservation biologist Thomas Sherry explains that the birds will endure long-term effects as a result of the oil arriving during their peak breeding season.
“When the adult birds get even a little oil on them, it gets onto their eggs,” says Sherry. “The tiny pores in the calcium eggshells allow carbon dioxide out and oxygen in. Since the oil is interfering with that gas exchange, the eggs will not survive.” Even small amounts of oil can directly kill the embryo inside the eggshell.
Sherry says there may be an even greater indirect effect from the oil spill cleanup operation.
“The whole food chain could collapse, at least locally, because of chemicals in the oil killing marine invertebrates and fish, and because the bacteria that feed on organic material like oil can increase and begin taking up more of the oxygen in the water,” Sherry says.
Birds indigenous to the marsh encounter oil directly as it washes ashore as well as through their diving, in which they swoop below the water’s surface to catch food. Once oil has coated a bird’s feathers, it is likely the bird will perish. To illustrate the effects of the weight of the oil covering the feathers of Louisiana’s seabirds, Sherry offers the image of a human trying to swim wearing a bulky winter coat. “It can be done, but eventually you’re going to get really tired."
While capturing and cleaning the birds is a humane endeavor, which Sherry supports, he also says the research on whether it really helps them survive after they are released is unclear.
“One of the scariest things is that the scientific community doesn’t have a clue how this is going to affect birds and other animals and for how long,” says Sherry. “The one thing we know for sure is that we’ll be dealing with this for decades to come.”
Tulane University, New Orleans, LA 70118 504-865-5000 firstname.lastname@example.org