Protecting the Watercress Darter

BSC and UA team assessing darter population size
- Photo Credit: Greg Harber
BSC and UA team collecting data on darters
- Photo Credit: Greg Harber
BSC biologists sorting through vegetation for darters
- Photo Credit: Greg Harber
Signs posting darter habitat at Roebuck Spring
- Photo Credit: R. Scot Duncan
Spring run within golf course at Roebuck Spring
- Photo Credit: R. Scot Duncan
UA biologist measuring darters
- Photo Credit: Greg Harber

What’s being done to save the Watercress Darter from extinction? The small fish faces many threats, and each requires a different solution (learn more about these threats here). The most important step in the fish’s protection was its being listed as endangered under the U.S. Endangered Species Act by the U.S. Fish and Wildlife Service (USFWS). Classification as “endangered” means that a species is on the brink of extinction; classification as “threatened” indicates a species will soon be on the brink of extinction unless sufficient conservation measures are taken.

Species protected by the act, and their ecosystems, may not be harmed without a permit from USFWS. Furthermore, USFWS is mandated by the act to help the species recover to the point that it is no longer endangered. Thus, the darter is protected by one of the most powerful conservation laws in the world.

A classification of the species from endangered to threatened status would be good news for the fish. What needs to be done to achieve this? The guidelines are explained in the fish’s recovery plan. Three conditions must be met: 1) long-term protection of three known naturally occurring populations; 2) long-term protection of at least one additional population within the historical range of the species; and 3) five years of data indicating that at least four populations are stable or increasing in size. The latest assessment of the species by USFWS (2009) determined that the criteria for down-listing had not been met.

Still, there’s reason to be optimistic for the future of the species. The creation of the Watercress Darter National Wildlife Refuge (managed by USFWS) in 1980 and the creation of a reservoir on the refuge to provide more habitats for the fish were big steps in its conservation. The Birmingham Audubon Society works with USFWS to help maintain the refuge. In 1988, a reserve population of the fish was successfully established in Tapawingo Spring (also known as Penny Spring) in Pinson. The Freshwater Land Trust protects this spring and its surrounding forest.

The discovery of a fourth natural population in 2003 at Seven Springs not only caught darter biologists by surprise, but inspired hope that this new population could become one of the long-term strongholds for the species. Faith Apostolic Church owns the spring, and under the leadership of Bishop Heron Johnson the church has been a careful steward of the spring. The church works with several conservation organizations and agencies to manage the spring.

The spring run at Roebuck Springs is home to a large population of the darter and passes through the Roebuck Municipal Golf Course. The city has ceased mowing up to the edge of the run and is allowing trees to establish in a buffer zone. While this is a nuisance to golfers with bad aim, this protects darter habitats in the run from stormwater runoff coming from the golf course.

Scientists are helping, too. Biologists from the University of Alabama at Tuscaloosa (UA) have monitored the population size of the darter. Studies by a UA graduate student revealed subtle genetic differences among several of the populations. Such information is important for maintaining a diverse gene pool for the species.

Biologists from Birmingham-Southern College (BSC) and UA have been studying the habitat requirements of the fish. At Roebuck Springs they’ve learned which habitats the fish prefers the most. They also discovered that the fish uses the runs that connect the spring pool to the nearest stream. BSC scientists and students are also studying whether populations of the Northern Crayfish (Orconectes virilis) – a predator of and competitor with the fish – can be controlled. Finally, a BSC program coordinates the efforts of volunteer citizen-scientists to monitor the water quality at each of the darter’s springs every month. Data are reported to Alabama Water Watch, a statewide stream monitoring program run by Auburn University.

Much, much more needs to be done to ensure the long-term survival of the species. Such efforts are not cheap, but investments in conservation are necessary to get the species down-listed to threatened status, and eventually delisted entirely. It’s a challenge for the City of Birmingham and other landowners to deal with having a highly endangered species on their lands. Life for them, as well as for the darter, will be much easier if the species can recover to the point of down-listing or delisting. If and when those days come, it will be a time for great celebration.

-R. Scot Duncan