Meanwhile, invasive Russian olive and red willow trees, both fire-prone species, have moved below the canopy. Bushfires used to be almost non-existent. Now they break out frequently. In 2017, the Tiffany Fire in southern New Mexico swept dry land, turning more than 9,000 acres of riparian aspen forest into charred ruins.
Instead of spreading widely across the landscape, the Rio Grande now flows primarily through a narrow channel, thanks to dykes built to contain the flow, which separate the main trunk from many side channels. This removes most of the meandering bogs, braids and cow bows that are home to silver minnows, once found throughout the river but now only found in 10% of their range.
For some, the answer to the Rio Grande’s existing problems is to restore some of the appearance of natural water flow.
“Optimizing spring runoff is a very important strategy because ecologically speaking, a whole bunch of them are tied to it,” said Paul Tashjian, Audubon Southwest Regional Freshwater Conservation Director. “Silver minnow spawns in the pulse. Poplar seeds fly in the pulse. Neotropical settlers build their nests during the pulse. If it happened a month ago, it’s a misfire. It doesn’t provide these benefits.”
One strategy is to store water in reservoirs and allow it to be released at the right ecological time – easier said than done, as water is scarce and mostly used on farms and pastures.
Thomas Archdeacon, a U.S. Fish and Wildlife Service fish biologist in Albuquerque, helps protect the dwindling silver minnows during megadroughts. He and his colleagues placed screens to catch silver minnow eggs as they flowed downstream. They plan to take the eggs to a federal fish hatchery, where the fish are raised. But there were no eggs the morning we went.
Another fundamental problem is that low flows and irrigation cause rivers to dry up in summer, leading to mass die-offs. “If 30 miles of river dries up,” Archdeacon said, “it will kill all the fish.”
By July, Archdeacon and others will be rushing down the dwindling river, catching fish stranded in pools and bringing them under a nearby dam, where they can survive in deeper, cooler water for some time.
The increasing frequency and scale of forest fires are also taking their toll on the Rio Grande. As we drove along the river near Santa Fe in early May, we could see huge plumes of smoke pouring from the raging forest fires.
“After the Las Conchas fire [near Los Alamos in 2011] The Rio Grande was hugely impacted,” Allen said. “It was an extreme fire, and it caused extreme flooding and mudslides. It adds incredible sediment and turbidity, and alters chemistry and biota. Large invertebrates and fish were wiped out. “
New Mexico is working to reduce the size of large swaths of forest to reduce the risk of major wildfires and prevent further fire damage to rivers.
Martin Baca has seen these changes firsthand. He was born and raised on a family ranch by the river near Bosque, New Mexico, where he grew hay for rodeos and pit bulls. He showed a bagel-sized belt buckle, which he won for high-quality bulls. Normalcy seems to be over, he said. “There is less water being used for irrigation and the wind is getting stronger,” he said. “You can irrigate and it’s dry in five days. That hot wind is like a hair dryer. And there’s no dew. You need to have dew. It helps the grass grow. But you can’t get dew with that wind.”
“The climate is changing,” he said, pushing up the brim of his cowboy hat. “I didn’t believe it at first, but now I do.”
The report in this article was obtained from water tablean initiative based at the University of Colorado Boulder Environmental News Center.