Saturday, November 15, 2008

The Key West National Wildlife Refuge may be celebrating its 100th-year anniversary, but managers are using the milestone to focus on global changes that could affect the refuge in the next 100 years.

The refuge is holding an anniversary celebration today at the Florida Keys Eco-Discovery Center at the Truman Waterfront in Key West.

As part of the celebration, which runs from 9:30 a.m. to 8:30 p.m., refuge managers are hosting a viewing of former Vice President Al Gore's movie on global warming, "An Inconvenient Truth." Global warming could have drastic impacts on the 200,000-acre refuge, which runs from the Eastern Dry Rocks west to the Marquesas Keys, managers say. Sections of mangrove islands in the refuge, which are home to Keys birds and a stopover for migrating birds, could be under water. Beaches could erode to a point where they no longer could provide nesting conditions for green and loggerhead sea turtles.

"While we are celebrating the first 100 years, we have to look closely at the next 100 years," Refuge Manager Anne Morkill said. "[Global warming] adds another layer of complexity to what we are already doing, which is dealing with invasive exotic plants and animals and their impacts on habitat."

Refuge managers are working with scientists at Florida International University on different sea-level models to determine the long-term impacts of global sea temperature increase and sea level rise, Morkill said.

Refuge managers, who have limited funds, already have their hands full dealing with managing human impacts on the refuge. Jet Skis and other personal watercraft are prohibited in the refuge. People are prohibited from visiting Wilma Key, a small island created by Hurricane Wilma that is a spring migration stop for many bird species. That move caused some backlash from the public.

"The wildlife takes care of itself," Morkill said. "Our primary mission is wildlife management. It's difficult to balance the needs of the public and of the wildlife, as public-use demands increase."

The control of invasive exotic vegetation is a main focus of refuge management, Morkill said. The colonization of islands by exotic plants drastically reduces wildlife use. Exotic species do not provide suitable nesting or food resources, and these species exclude important native plant species, Morkill said.

Key West National Wildlife Refuge, one of the earliest refuges in the United States, was established in 1908 by President Theodore Roosevelt as a preserve and breeding ground for native birds and other wildlife. The refuge comprises more than 200,000 acres, with only 2,000 acres of that on land. The area is home to more than 250 species of birds and is important for sea turtle nesting. The islands are predominately mangrove with limited shoreline and salt ponds.

The refuge is home to the piping plover and bald eagle, as well as other regionally significant species such as the great white heron, reddish egret and white-crowned pigeon. Birds in the refuge are doing well, according to recent bird populations and nest numbers. There has been some decline in white-crowned pigeons.

Refuge managers survey sea turtle nests each year to track nesting and reproduction of the green, hawksbill and loggerhead sea turtles that frequent the area. There are few beaches in the refuge suitable for sea turtle nesting, thus there are typically fewer than 50 nests found each year, according to refuge managers.

Green sea turtle nests are increasing, which is a positive sign, because green sea turtle activity has not changed in several years. The low number of nests makes it difficult to determine nesting trends, but activity appears to be stable, according to refuge managers.

tohara@keysnews.com