Bay dredging project threatens vital Miami reefs

Environmentalists are racing to rescue delicate corals off the coast of Miami. But underwater reefs are being threatened by a nearby project in the city's port, CBS News correspondent Vincente Arenas reports.

The Army Corps of Engineers is dredging the port of Miami to make way for much larger container ships that will pass through the new Panama Canal expansion at the end of next year. But underneath the bay is a coral reef that environmentalists say is in immediate danger.

"There's sort of this color gradient, between the clear water and this very dirty water, which is the suspended sediment," said marine biologist Colin Foord

A few miles off the coast of Miami, Foord is fighting to save what most people can't even see.

"The entire health of the ocean is dependent upon corals and coral reefs," he said.

Foord says the corals, just 25 feet below the surface, are in danger. They're being covered in silt and churned up by the massive dredging machines nearby, which the Army Corps is using to deepen the port of Miami and make way for the massive container ships.

"Corals have colonized the shipping channel; that actually provides a great habitat for corals to utilize," Foord said.

It's estimated that more than 90 percent of Miami's original coral has already disappeared.

The remaining corals found in these waters are extremely resilient, making them more important for researchers around the world.

"You can take these corals and you can transplant them back out to the coral reef where, you know, we can re-grow the coral reefs that have been in decline," Foord said.

Rachel Silverstein is director of the Biscayne Bay water keepers. She says the expansion project violates the Endangered Species Act.

"Miami is going to pay the price ultimately with a dead reef when the Army Corps leaves town," Silverstein said.

Susan Jackson, spokesperson for the Army Corps told CBS News, "We will continue to use the best science, engineering and technologies available to minimize impacts to the human and marine environments."

Foord's organization, Coral Morphologic, has moved over 300 corals to safety. But with the blasting phase of the project scheduled to begin in October, Foord is racing to rescue even more.

"If corals and coral reefs collapse, we will most certainly see a collapse of other ecosystems and other ocean and populations of fish in decline," he said.

Foord's organization is planning more dives. The Army Corps expects to be finished dredging by the middle of next year.