The Life Aquatic

Will the Mexican garter snake get a break?

It's always the details of loss that still jab. Take the Mexican garter snake: Back when rivers actually streamed through Tucson, those waters hosted a nifty array of such aquatic creatures.

Today, like our rivers, Mexican garter snakes are history in this town. Biologists say their overall population north of the border has dwindled to several hundred, with an unknown number in Mexico.

Still, there may be hope for the snake, if not for their long-vanquished Tucson home. Earlier this year--in response to a lawsuit--the U.S. Fish and Wildlife Service announced plans to review the garter snake's dilemma.

But with good news comes bad: Even considering this creature for a listing opens a pricey, bureaucratic Pandora's box.

The federal agency now has until Sept. 15 to render a decision. That analysis will lead to one of three conclusions, says Fish and Wildlife spokesman Jeff Humphrey. First, the agency might decide the snake doesn't warrant protection. Second, it might decide that protection is warranted.

Third--and some say most likely--FWS officials could grant the snake a "warranted but precluded" status, meaning it deserves protection, but has to take a number and join scads of other species awaiting protection.

If the latter is picked, a lawsuit will soon follow. That's according to Noah Greenwald, a conservation biologist with the Center for Biological Diversity. The center has already been to court once over the snake, after the FWS failed to act on a 2003 petition to review its status.

Greenwald says such foot-dragging is typical of this Republican era. "The Bush Administration has only listed 41 species (as endangered) in the five years they've been in office, compared to 512 under the Clinton administration and 234 under the former Bush administration."

Given that pattern, "the Fish and Wildlife Service basically won't issue findings on petitions without being sued," he says.

But Fish and Wildlife spokesman Jeff Humphrey says it comes down to money. "We're held to only the amount Congress provides us for listing activities."

And those activities are intricate. "Because there's a backlog of species awaiting protection under the Endangered Species Act, we would first categorize the Mexican garter snake," he says. That designation is based on several key elements. "How unique is the species? Is it a subspecies (as in this case)? Is it a full-blown species? Or if it's the only species in a genus, that would rate it very high, taxonomically."

Then again, the garter snake could land in "warranted-but-precluded" limbo--making costly litigation a near certainty. "If it ends up as warranted but precluded, it would not be unusual for someone to kick it out of the numeric prioritization by getting a court order," Humphrey says.

If this seems a rather inefficient way of doing business, it is. The U.S. Government Accountability Office notes as much in an April report: "As we have reported in the past, there is a long history of extensive litigation on implementation of the Endangered Species Act that has consumed significant program resources. ... A proactive response to this issue could save the services significant resources in avoided future litigation."

But don't count on pro-action anytime soon; ironically, the FWS doesn't have much incentive to go there. It's a matter of "which pot the money comes from," says Humphrey. "Litigation is paid out of a different pot than that which Congress provides us for listing." In other words, the Justice Department would field the court battles.

Here's the rub: "For the taxpayers," he says, "it is a more expensive route, because frequently, the plaintiffs go back to court and seek attorneys' fees if they win the case. And taxpayers pay that, too."

With all of these funding snafus and legal shenanigans, sometimes we forget that creatures like Mexican garter snakes hang in the balance. But Dr. Phil Rosen doesn't forget. The UA herpetologist has long charted the snake's demise, and says listing the reptile might finally spotlight Arizona's aquatic-species catastrophe.

"In part, it would to be a recognition that we've really got the entire aquatic ecosystem in danger," he says. "Most of the fish are already listed, and a couple of the frogs are either listed or extinct."

Even consideration of an endangered species listing "would bring resources and management from all agencies to focus on this species. They would immediately start to take an interest in what they're doing to promote its survival and recovery."

At the same time, something about this snake's plight is particularly poignant, Rosen says. "People used to come to Tucson and find Mexican garter snakes in pretty good abundance. They were in the Santa Cruz River where Congress Street is now, and further to the west."

He says they finally disappeared from their last local stronghold, in the Fort Lowell area, in the 1970s. Although there remain "at least a few hundred Mexican garter snakes in the United States," he says, "that's not a viable population.

"And we know less about their status in Mexico. But undoubtedly, the processes affecting them in the United States are also on the march there. Mexicans haven't damaged the aquatic environment to the extent we have, but unfortunately, the same things are spreading."

Dying rivers are only a part of the problem, he says. Another huge factor is the introduction of non-native species such as crayfish, sports fish and bullfrogs. For example, "bullfrogs eat young garter snakes, and they also spread a disease among leopard frogs, which are the primary prey of Mexican garter snakes."

Then comes "just plain old garden-variety habitat destruction. Habitat modification has limited the cienega and riverside habitat that (the snakes) occupy in Arizona."

At the same time, these small snakes factor into the big ecological picture--what Rosen calls "a classic example of cascading effects." Those effects flow upwards from fish and frogs to snakes that eat the frogs, and then birds that eat the snakes. Pull one leg from that chair, and you have the makings of disaster.

"Listing the Mexican garter snake is the right thing to do," says Rosen, "and it will be helpful--if we assume that we're not going to finally, totally destroy the native aquatic ecosystem and biodiversity of the Sonoran Desert region."

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