Tarballs are common byproducts of oil spills, said Ronald Kendall, an environmental toxicologist at Texas Tech University. The sticky masses can form when ocean waves concentrate surface oil slicks into clumps, which then wash ashore.
In the meantime, every effort should be made to clean tarballs off beaches and other sites where they wash ashore, Kendall said.
Photograph by Brian Snyder, Reuters
Broken Tarball From Gulf Coast
A 5-inch-wide (13-centimeter-wide) tarball that washed up on an Alabama beach sticks to a person's gloved fingers as it's broken apart for inspection on Sunday. As with liquid oil, sticky tarballs can be hard to clean off animals' feathers and fur.
Oil—regardless of what form it takes—can also be dangerous to plants. "It has physical properties that are not good for habitats," Kendall said. "If it settles on grasses or marine plants, it basically kills" them. (See "Nature Fighting Back Against Gulf Oil Spill.")
Photograph by Kari Goodnough, Bloomberg/Getty Images
Oil and Water in the Gulf
Reddish blobs of oil float on the surface of the Gulf of Mexico, as seen on May 5 off the Louisiana coast.
Oil is naturally buoyant, but the chemical dispersants that cleanup crews are using to break up and scatter the surface slicks cause the oil drops to sink deeper into the water column, Kendall said.
"Fish, particularly larval fish, can be killed" by the dispersed oil droplets, he said. "And if it sinks to the seafloor, it can be toxic to bottom-dwelling organisms such as crabs and marine worms." (See "Gulf Oil Spill a 'Dead Zone in the Making'?")
The environmental effects of the oil "are real complicated, and the more oil that continues to be released, the more complicated it's going to be," Kendall said. "Dose makes the poison, and right now we've got a big dose of oil in the Gulf of Mexico."
Photograph by Carlos Barria, Reuters
Oil scooped from the surface of the Gulf of Mexico stains a reporter's hands on May 10.
The 2010 Atlantic hurricane season, which begins June 1, presents a looming danger for the Gulf cleanup efforts, Kendall said. Strong storms would halt cleanup efforts and could scatter the oil slick to faraway places.
An oil-soaked seabird struggles against the side of the HOS Iron Horse supply vessel as the ship sails near the site of the Gulf oil spill on May 9.
The U.S. Gulf Coast serves as a winter resting spot for many U.S. waterfowl and tropical migratory birds. What's more, the spill is happening during nesting season for numerous shorebird species.
"If oil gets on a bird's feathers, it reduces the insulation quality of the feathers and makes the bird susceptible to hypothermia," Kendall said. And if the bird ingests the oil, the results will be even worse, he said, as the toxic substance can affect the animal's liver, kidney, or gastrointestinal tract.
If a nesting bird that has been exposed to oil manages to get back to shore, the bird could get oil on its chicks and potentially kill them.
Photograph by Gerald Herbert, AP
Beached Dolphin on Gulf Coast
A dead dolphin lies on the beach on Horn Island, Mississippi, on May 11. Officials say that at least six dead dolphins have been found along the Gulf of Mexico coast since May 2.
Authorities don't yet know whether the animals died due to the Gulf oil spill. But Kendall said oil is a likely culprit.
"I'm not surprised that we're seeing dead dolphins already," he said. "Dolphins have to surface to get air, and if they surface through oil and they're inhaling, they're going to suck the oil down their airways."