Sunday, March 21, 2010

Shelley Alexander on the loss of Sea Grass

Shelley Alexander, Manager of the Northwest Florida Aquatic Preserve Office, spoke to the University of West Florida’s Environmental Reporting class on March 17 about the decline of sea grass in Pensacola.

Alexander said that sea grass was not only just underwater décor, but an important habitat for fish and aquatic sealife.

“Sea grass grow in non-secluded, wave-free areas,” she said.

The Aquatic Preserve is responsible for managing the 40,000 acres of submerged land in the Ft. Pickens area. They also manage the Yellow River Preserve (a class 3 preserve strictly meant for fishing and recreation), the Rocky Bayou Preserve and the St. Andrews Preserve in Panama City.

Alexander said that large industrial point sources made in the 50s and 60s were a detrimental cause to sea grass declination. Chemicals such as NH4 and PCB were being released into the water.

The result of overfishing is also a large cause, which can be sited in the smaller catch rates that can be seen in trophy fish over the years.

When overfishing occurs, large predators are gone, leaving small predators. The loss of mesograzers in the area lead to an increase in algal epiphytes, a fungi that destroy sea grass.

Hypoxia, the result of the oyster removals done in the past, is also another cause to the decline in sea grass.

“We still have hypoxia in deeper portions of the bay today,” said Alexander. Hypoxia and fish kills in the late 70s lead to plans of action.

Alexander also said that the freshwater sea grass of Pensacola disappeared, having moved to the southern shore of the Gulf Breeze Peninsula, as demonstrated on a map.

“Gulf Breeze needs to keep sea grass at its restoration state,” she said.

As of 1992, the sea grass that is still present does not exceed two feet.

Alexander said she is currently at work trying to restore sea grass in nearby areas by method of transplanting units where prop scars (spaces with no sea grass) are present. Thallasia is the plant being used to restore sea grass. She said its slow growth rate of about 20 years will take a while to observe.

In the mean time, other forms of awareness are being thought of to prevent sea grass destruction.

One such form of awareness are the “No combustible engines” signs placed in sea grass territory.

“This has been proven to help protect the sea grass,” Alexander said.

$1000 dollar fines are also being issued to those who refuse to obey these signs.

For more information on the Northwest Florida Aquatic Preserve, visit the main Web site at


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