Scientists are focusing on phosphorous' effects, but a Fort Pierce scientist says nitrogen in the water flowing into Florida Bay is also a threat to coral.
By Associated Press
Published February 25, 2004
MIAMI - Efforts to clean up and restore the Everglades may end up hurting another state environmental landmark - coral reefs off the Florida Keys.
As the $8-billion Everglades restoration project increases the water flow into Florida Bay, nitrogen in the water may kill coral, said Dr. Brian Lapointe, a scientist at the Harbor Branch Oceanographic Institution in Fort Pierce.
The restoration is designed to clean up water passing through the region and return some of the historic water flow to the bay. Though the project will filter pollutants from the water, the focus is largely on phosphorus, which scientists say poses the most serious threat to the Everglades.
But Lapointe said nitrogen, which comes from farm runoff, sewage and other places, is another culprit. Nitrogen feeds algae, causing it to burgeon and compete with coral, he said. That type of plant growth also clouds up the clear water that corals prefer.
Lapointe said there has been an example of this phenomenon in the Keys already. Between 1996 and 1999, after an increase in the flow of water into the bay, 38 percent of the living coral in the Keys died off. Lapointe attributed the problem to "nitrogen overloading," causing an explosion in algae blooms.
The Keys reefs began to recover when officials decreased the water flow in 1998, Lapointe said.
He said as Everglades restoration increase the flow again, the reefs will again be in danger.
Dr. David Rudnick, a senior scientist with the South Florida Water Management District, which helps coordinate the Everglades restoration effort, said researchers are still studying nitrogen's effects.
Because the project concentrates on the Everglades, officials pay less attention to the marine environment, and therefore less attention to nitrogen.
"In the Everglades, phosphorus is so overwhelmingly important that the (most) attention is paid to phosphorus," he said. But if studies find that nitrogen is damaging the bay, officials will change their plans.
"When we start manipulating an ecosystem of this scale ... there are going to be changes that are unpredictable, and that understanding of our limitations is built into the program," he said.
Rudnick said the filtering action that removes phosphorus from the water also screens out 30 to 50 percent of the nitrogen. So if water flowing through the region increases by that amount, the net effect will be even, he said.