Open Spaces: Alabama: Small Changes Can Spell Big Trouble for Vulnerable Species

Alabama: Small Changes Can Spell Big Trouble for Vulnerable Species

A diamondback terrapin sits in grass

Diamondback terrapins were once abundant on Dauphin Island, Alabama.  Now, they need state protection in order to survive. Photo: Ryan Hagerty, USFWS. Download.

In Alabama, folks embrace their natural resources.  From the sea turtles and manatees of the Gulf Coast, to the darters and mussels of northern Alabama streams, the state has some of the most diverse wildlife in the nation. This incredible variety of species includes many that are rare, and some that are imperiled.

More than 113 of Alabama’s species are now listed as threatened or endangered, including some 61 freshwater mussels, 10 reptiles, and 21 plants. With so many imperiled species in their care, U.S. Fish and Wildlife Service biologists take climate change seriously.  That’s because slight changes in climate can affect the survival of a species.

“Small environmental changes can have big effects in a relatively short period of time, particularly when you are considering such powerful ecosystem drivers as temperature and moisture,” explained Dan Everson, Deputy Field Supervisor for the Service’s Alabama Field Office.  “Many of the plant communities we have come to know and love on the Gulf coast are responsive to relatively subtle changes in moisture.  Because of the flatness of the coastal plain, a few extra inches of ground water, a few extra floods, a slight change in elevation of the tides, or even a few extra inches of rain per year may determine whether our children will continue to admire a slash pine woodland with an understory of pitcher plants and toothache grass, or find themselves instead tripping over cypress knees and palmetto crowns in a tupelo swamp.”

Recently hatched sea turtles in a styrofoam box filled with sand
Sea turtle hatchlings off the coast of Alabama. Warmer temperatures during incubation could affect the sex of the turtle. Photo: Dianne Ingram, USFWS. Download.

Those types of changes, of course, don’t just affect plant communities. They also affect the animals that depend on them.  Alabama reptiles may be among those at risk. The state reptile, the Alabama red-bellied turtle, along with sea turtles and gopher tortoises, may face detrimental effects when it’s time to nest.  The red-bellied turtle lives in the tidal freshwater marshes at the head of Mobile Bay estuary.  As sea levels continue to rise, and saltier water changes the species composition of the submerged plants the turtle feeds on, the turtle’s preferred habitat will migrate inland, unless sea walls and other manmade barriers prevent it.

Temperature changes are a concern as well.  “The nest of these reptiles depends on temperature to incubate the nest and determine the sex of the hatchlings,” said Service biologist Bruce Porter.  “Warmer nests mean more female hatchlings.  We need to understand how turtle populations respond to warmer nesting sites, and ensure we maintain habitat to allow them to survive.” 

Biologists are also keeping an eye on the diamondback terrapin, a reptile once commonly found in the marshlands of coastal Alabama.  Today, the terrapin is listed as in “greatest conservation need” by the state of Alabama.  State biologists believe climate change has contributed to the terrapin’s decline.

“The rising sea level, more intense storms, and loss of habitat have caused problems for the diamondback terrapin,” explained Jim McHugh, state Wildlife Coordinator with the Alabama Division of Wildlife and Freshwater Fisheries. 

A group of researchers at the University of Alabama at Birmingham, headed by biology professor Dr. Thane Wibbels, has studied the terrapin for a number of years.  The species was once abundant at Cedar Point marsh on Dauphin Island in the 1800s, but the population has since declined dramatically.  Wibbel’s research predicts that sea level rise and the loss of salt marshes could result in the “disappearance of the terrapin in some locations.”    

The loss of salt marsh is anticipated based on the current, widespread practice of building bulkheads, seawalls, and rip-rap in an attempt to keep ahead of the inexorable rise of Gulf waters.  From tidal riverbanks to open-water shorelines, the biological integrity of the Mobile Bay estuary is threatened by an ever-expanding wall of treated lumber, stone and cement, explicitly designed to keep water from interacting with the land. The bulwarks leave no room for salt marshes to migrate inland.

Service biologists are reaching out to partners and citizens alike in an effort to allow the Alabama coast to adapt to changes and preserve our wildlife. 

“At the Alabama Field Office, we are educating folks about the advantages of using a resilient, living shoreline approach to protect against storm damage and erosion.  We understand that our biologically rich coastal ecosystems depend on interactions between aquatic and terrestrial processes and species. Instead of creating barriers between our waters and lands, we have made it a priority to implement restoration projects that can slow erosion, but also allow coastal species to thrive,” said Everson. 

A living shoreline helps combat erosion by restoring the natural shoreline habitat using plants, sand, rocks, oyster shells and other natural materials to attenuate wave energy, and create conditions favorable to establishing vegetation. Shoreline property owners will benefit from reduced erosion and more wildlife, and coastal species like the terrapin will continue to find the nesting beaches and salt marshes they need to survive. 

 

Climate Change Focus: Adaptation, Engagement

Author: Denise Rowell, USFWS, 251-441-6630, denise_rowell@fws.gov

Contact: Dan Everson, USFWS, 251-441-5837, dan_everson@fws.gov

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Last updated: June 21, 2012