After a flood of legal challenges, the U.S. Fish and Wildlife Service has declared two, tiny native fish endangered and listed some 710 miles of stream as critical habitat — including 84 miles Rim Country.
The critical habitat designation means federal agencies will have to consider whether their actions or approvals might harm the tiny spikedace or loach minnow in Tonto Creek, Fossil Creek, Rye Creek, Spring Creek, Rock Creek, Greenback Creek and the Verde River.
Drought, water diversions, cattle grazing, non-native predatory fish and gradual climate change have nearly wiped out the once widespread, three-inch-long fishes, which live in small, shallow, swift-running streams that have stretches of clear gravel in which they can lay their eggs. The fish have vanished from 90 percent of their range in Arizona and New Mexico.
“Federal recognition of the precarious status of these two fish species should raise a general alarm — we need to take emergency action to protect Southwest rivers and streams,” said Noah Greenwald, endangered species director at the Center for Biological Diversity. “These two fishes aren’t an isolated example; there’s an extinction crisis across the board in southwestern rivers. Habitat destruction and invasive species are putting nearly all the native fish, frog and other aquatic species at risk.”
U.S. Fish and Wildlife spokesman Jeff Humphrey said, “Critical habitat applies to federal agencies: so when a federal agency is going to conduct an activity — build a bridge or whatever — if they determine that their activity will have an effect on the habitat, they are required to consult with us.”
The critical habitat designation does not affect private land. It should also have little effect on recreational use of the streams or the diversion of water that does not disrupt “necessary habitat features.”
Cattle grazing is not “incompatible” with the survival of the fish, but ranchers with federal leases will have to consider how their activities will affect the streams on which the fish depend.
In Rim Country, the designation mostly affects Tonto Creek and its tributaries, all the way down to Roosevelt Lake. Plans to build a bridge, improve flood control and graze cattle in that area could now require consultations designed to minimize impacts on the already fading fish. The lower end of Fossil Creek is also critical habitat for the fish, adding one more endangered species to an already impressive list. The Forest Service recently closed the road from Strawberry to Fossil Creek, in part because of its inability to control the impact of large weekend crowds on the stream.
The fish also occur throughout the Verde River system, including tributaries like Oak Creek, Wet Beaver Creek and West Clear Creek.
Once widespread, the fish are now common only in Aravaipa Creek in southeast Arizona and some parts of the upper Gila River in New Mexico. Biologists have reintroduced the fish into Fossil Creek and a few other locations.
Actually pint-sized members of the carp family, both the spikedace and the loach minnow hang out on the bottom picking off the underwater larva of midges, blackflies, mayflies and mosquitoes. The two fish are almost indistinguishable, although the loach minnow has white spots that distinguish them from their fishy cousin.
The hardy little fish thrive in capricious, flood-prone desert rivers, showing an uncanny ability to find cover and hunker down to avoid getting swept away by the fierce flash floods that once defined rivers and streams in the region. They can also take advantage of floods to spread down the deep murky waters of a main river stem like the Verde River to colonize tributaries downstream that have the clear, shallow, fast-moving water they need to breed.
However, dams and diversions have changed the natural flood regimes of streams throughout the region. In many cases, once reliable streams dry up now for months at a time, wiping out fish populations. Moreover, the dramatic change in stream conditions has given introduced competitors like shiners and fathead minnows an advantage they wouldn’t have if floods continued on their normal cycles.
“When these events occur, it’s a pretty interesting dynamic,” said Humphrey. The non-native species don’t weather flash floods as well: they’re Midwestern fish adapted to slow-moving waters. So those floods really push the non-natives back down out of the system. Then for a year or two, until the non-native fish make their way back in, you have a spike in the native population.”
The spikedace has hung on in more places than its seemingly identical relative the loach minnow, which does better in higher, colder streams — which have been severely affected by cattle grazing and the effects of a long drought.
The fish have also been hard hit by the devastating change in wildfire patterns throughout the region. They evolved in a world where low-intensity fires burned through the forest and chaparral every few years. Such fires mostly enriched the soil and generally didn’t cause a big increase in erosion that would fill streams with silt. By contrast, after a century of grazing and fire suppression, catastrophic crown fires, like the Wallow Fire this past summer, now predominate. Such fires consume almost all the vegetation and burn so hot the soil becomes “hydrophobic,” which means it can’t easily absorb water. After such a fire, streams fill up with mud and silt — burying the stream-washed gravel beds fish like the spikedace and loach minnow need to survive.
The listing of the little fish and their critical habitat caps a torturous legal battle. The Center’s filings prompted a critical habitat designation in 1994, but it was overturned on a technicality. Another filing prompted the Fish and Wildlife Service to propose 900 river miles of critical habitat in 1999. The Arizona Livestock Association filed its own action, resulting in another round of revisions. The USFWS designated 500 miles of critical habitat in 2007, after Department of the Interior officials in Washington overruled scientists. Several counties and the New Mexico Cattle Grower’s Association challenged even that reduced critical habitat designation, leading to a new round of court hearings.
In 2009, a federal judge not only rejected that challenge — but ordered the U.S. Fish and Wildlife Service to determine whether the proposed 500 miles of critical habitat would actually save the species.
That resulted in the most recent designation, which actually totals more than 900 miles if you count streams on several Indian reservations already protected by management plans, a stretch of stream owned by a mining company and a stretch of the San Pedro River, which was excluded in the interests of national security — since it would affect the Fort Huachuca military base near Sierra Vista.
Advocates for the fish hope the designation will provide one more tool to protect Arizona’s streams or rivers, almost all of which have been affected by dams, diversions, droughts, grazing and fires. An estimated 90 percent of Arizona wildlife depends on these streams and rivers at some critical stage of their life cycle.
“Saving endangered species means protecting the places they live,” said Greenwald. “Critical habitat will let these two small fish survive, yes, but it’ll also benefit the people of the Southwest, who will still have the chance to see living rivers.”