���Ϲ���

On Monday afternoon, under a thick rolling fog, two tankers collided in the Houston Ship Channel in Houston, Texas, one of the busiest industrial seaports in the United States. The clash caused a toxic leak in one of the ships, sending an unknown amount of hazardous chemical methyl tert-butyl ether (MTBE) into the water ( the spillage amounted to 100,000 gallons). The exact cause of the collision is unknown, but it involved the Dutch Carla Maersk, an outgoing chemical carrier ship that was transporting 216,000 barrels of MTBE, a gasoline additive, and the Liberian Conti Peridot, a bulk cargo carrier.

The leak itself is currently under control, but the contaminant hasn't been contained, making conservationists nervous about its potentially harmful journey into protected wildlife areas nearby. In this region the threat of pollution is constant, and history indicates that when industry fails, wildlife take the fall.

Here’s what you need to know about the situation.

What is MTBE?

MTBE is colorless, flammable, and ; it reportedly smells like paint-thinner. “It is water soluble, and there is no way of preventing it from dissolving into the water column,” Capt. Brian Penoyer from the U.S. Coast Guard, said during a press conference.

Until 2005 it was in the United States as a gasoline additive. Several states have since banned the substance after multiple were filed against oil companies for ground and drinking water contamination. The United States still , however, which is why the tanker in Houston was loaded with it. 

The chemical is transported in liquid form, but when it’s released into open water and makes contact with air it evaporates. Already, two dockworkers on the channel have been hospitalized after inhaling the chemical. The residents of Morgan's Point, a town adjacent to the channel’s mouth, were urged to stay indoors by the Coast Guard on Monday night.

Did this happen near important habitat?

Galveston Bay, which lies at the mouth of the channel where the spill occurred, is a large, semi-enclosed body of water where rookeries and sanctuaries provide habitat for birds. Some of these spots are managed by ���Ϲ��� Texas and Houston ���Ϲ���. Two of the main sanctuaries are Smith Point Island and Vingt-et-un (21, in French), which are closest to the source of the spill. Vingt-et-un is historically important because in the 1920s, it harbored one of the on the Texas coast. After decades of erosion and the effects of changing land use in the area, it was undermined. Now, ���Ϲ��� Texas is trying to rehabilitate the area to bring it back to its former glory, says Amanda Hackney, the coastal program manager at ���Ϲ��� Texas. Depending on the weather in the coming days, winds and ocean currents could send the MTBE to these important sites—if it's not contained soon.

How does MTBE affect wildlife and birds?

The Environmental Protection Agency has found that MTBE to wildlife: High concentrations of the chemical have been proven to cause tumors in animals. “It is known to be pretty toxic to aquatic life at certain concentrations,” says Brian Trusty, executive director at ���Ϲ��� Texas, which is closely watching the spill. Since the contaminant can also be lethal to fish populations, ���Ϲ��� Texas’s major concern is that the chemical might disrupt the food chain and harm birds in local rookeries.

Birds that flock to the area include Great Blue Herons, Great Egrets, Neotropic Cormorants, American Oystercatchers, and Brown Pelicans, and they’re in the midst of their breeding season. That means that they'll be heavily dependent on fish to feed their young, Hackney says. If the spill reaches the fish, they’re in a boatload of trouble. “I've got a lot of birds showing up this time of year. This is a bad time to be without food,” Hackney says. Without sufficient amounts of healthy fish, nestlings could face a high mortality rate, which would put a dent in future populations in and around Galveston Bay.

What’s being done to protect the birds?

Clean-up crews have been handling the spill so far. The slick is two miles long and its implications are still unknown. ���Ϲ��� Texas is being cautious and actively monitoring the bay in conjunction with local organizations like the . Volunteers are also on the lookout for any signs of foul play on the coast, such as dead fish washing ashore, or unprecedented algal blooms in the bay. Hackney says that residents in the area can alert ���Ϲ��� about unusual signs by using an provided by the . ���Ϲ��� Texas also works with local conservation organizations to frequently assess the ecology of the bay, and it runs the , which encourages citizen scientists to keep an eye on the region’s birds.

How did this happen?

The Houston Ship Channel collision was the second one in five days (though the didn’t release any pollutants into the water), and comes almost exactly one year after another clash occurred between a tanker and a barge. That , in March of 2014, sent 4,000 barrels of oil pouring into the sea.

“We are concerned about the fact that [vessels] continue to run into each other,” Trusty says. “This is another case that really underscores the need to improve technology on board these tankers.” Better use of the Houston Ship Channel would mean conservationists don’t have to be on constant calamity-alert. “I think the bottom line is that this part of the Texas coast is very dependent on these industries, so we don't want to see them leave,” Hackney says, “But we want to make sure the industries can conduct themselves safely, too.”