Panama canal expansion could bring invasive species

Brett Smith for redOrbit.com – Your Universe Online

Ever since it was opened in 1914, the Panama Canal has been an invaluable way to pass ships from ocean to ocean, but the canal has also been a way for invasive species to invade the Gulf of Mexico and the waters beyond.

According to a new study, the problem of invasive species is only expected to get bigger as the on-going expansion of the canal is expected to be finished and open for business in 2016. The expanded canal will allow ships traveling from Asia to pass directly into the Gulf, rather than stop off on the West Coast as many currently do.

The study, from a team of Smithsonian Institute scientists, concluded that about one-quarter of the ships that currently visit the West Coast will not travel directly through the Gulf of Mexico.

Bubbling ballasts bring baddies

An expanded Panama Canal is wonderful commercial news, but more ship traffic leads to a higher risk of introducing invasive species via ballast water discharge. Many cargo ships use a large tank of water called a ballast to add stability when the cargo hull is empty. The crew drains the ballast tank once the ship reaches its destination and fills its cargo bay, potentially introducing invasive species to a new environment.

[STORY: Study on invasive species shows Darwin had it right all along]

The study team found that the quantity of ballast water introduced in the standard East Coast port will almost double in the initial five years of the canal’s expansion and jump by 78 percent along the Gulf. The wetted surface area for ships will almost triple in both locations.

Both calculations mean a many more opportunities for invasive species to hitch a ride, and then get dumped off in foreign waters. Some foreign species would have no natural predators, leaving their population growth unchecked.

“This study is basically a warning flag, pointing out hot spots where the increase of traffic is likely to occur,” study leader Jim Muirhead told National Geographic.

One of the more infamous examples of an invasive species introduced via commercial shipping is the zebra mussel infestation of the Great Lakes. Originally from Eurasia, zebra mussels showed up in the Great Lakes in the 1980s. Without any natural predators, the population of the mollusks exploded – causing them to clog water intakes and become a major nuisance.

[STORY: Warming Atlantic temperatures could increase range of invasive species]

The current Panama Canal expansion is only expected to increase the odds of another such invasion. The expanded canal will be able to accommodate ships up to 1,200 feet long and 160 feet wide, which is 235 feet longer and 54 feet wider than its current limits.

Call to action

Many ports along the Gulf and East Coast are expanding in preparation for the influx of larger ships. The Gulf ports are expected to see more supertankers and these petroleum-hauling juggernauts often release large volumes of ballast water because they are either completely loaded with cargo or completely in ballast.

Muirhead, a postdoctoral researcher at the Smithsonian, said preventative steps need to be taken – starting now.

“If you know where some of the hot spots are likely to occur, you can focus management efforts to prevent invaders from getting there in the first place,” he said.

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Source: http://www.redorbit.com/news/science/1113340049/panama-canal-expansion-could-bring-invasive-species-022415/