With boating season poised to kick off on Memorial Day weekend, it’s time to become vigilant over aquatic nuisance species — ANS, for short. These non-native troublemakers often physically change local ecosystems by altering traditional food chains, damage water infrastructure and degrade water quality, as well as limit fishing and recreational opportunities.
In Colorado, the main threat is zebra and quagga mussels, two freshwater species that are closely related and originated in Western Europe and Eastern Asia. These critters seek out dark and discreet crevices and clefts and fasten themselves to the underside of boats for protection.
Last year was a record year in the state for the number of boats found to possess these mussels by Colorado Parks and Wildlife (CPW), the agency charged with most recreation, fish and wildlife management. By this same time in 2015, inspectors discovered three boats with the nuisance species and pinpointed 24 by the end of the season.
“It’s a real threat,” said Robert Walters, invasive species specialist for CPW. “In 2016, we’ve already intercepted five watercraft coming into the state with confirmed zebra and quagga mussels, so we’re on pace to exceed what we did last year.”
This particular invasive species removes major quantities of plankton, which act as food for juvenile fish, and other nutrients from the water. On top of that, if zebra and quagga mussels then go undetected and a boat encrusted with them launches into a different body of water and unintentionally transfers them, it is practically impossible to remove them permanently once they occupy it.
At many well-attended boating spots throughout the state, CPW relies exclusively on boater education programs through prevention campaigns and instructive signage to offset ANS issues. There are other locations, though, that are considered high-priority or high-risk due to their proximity to the Front Range.
On the White River National Forest, there are just three reservoirs that are considered at heightened risk from these invasive species entering the water from boaters. Those are Dillon Reservoir, Ruedi Reservoir near Basalt in the Aspen-Sopris Ranger District and the Green Mountain Reservoir on the northern end of Summit County along the Blue River.
Denver Water, which manages Dillon Reservoir, pays for boat inspectors before vessels launch if they’ve been out of state or for residents if they’ve been in local, known infected water. Inspectors at the Ruedi and Green Mountain have in the past been financed by a combination of U.S. Forest Service regional dollars that get split up among the many districts, in addition to CPW funding.
But, as annual Forest Service budgets continue to dwindle — the White River had a general allocation of $31 million five years ago and for 2016 is operating on just $18 million — the local districts have had to make difficult choices and purge maintaining reserves for nonessential programs such as invasive species prevention. The Ruedi still has some funding streams to keep its program running, but Green Mountain has been less fortunate.
“As we’ve declined in our funding, we’ve had to prioritize what we do at the forest level,” said Bill Jackson, Dillon district ranger. “So what do we fund — seasonal employees, people, other programs or (invasive species)? Those are tough decisions to make, and some people think (infestation) is inevitable or don’t think that it’s money well spent.”
The predicament is, however, that without proper prevention measures, the cost of potential mussel contamination can be much, much higher. On some multiuse reservoirs around the country — Green Mountain is also the location of the Green Mountain Dam — maintenance can skyrocket where these problem species land because they can cause water treatment, irrigation and power generation facility snags.
“If there were quagga and zebra mussels in there,” said County Commissioner Karn Stiegelmeier, “it would cost millions and millions of dollars annually. There is a huge, very expensive problem with them in Lake Powell, for instance, and a lot of Arizona reservoirs.”
Pueblo Reservoir is the only one in the state known to have the quagga mussel, though those spotted have only been in a developmental larval stage known as a veliger. While not yet pervasive, the goal remains to avert this problem in other favorite, yet susceptible, sites for boating such as Green Mountain.
“It’s just the veligers that have been detected,” Mike Porras, CPW’s public information officer, said of Pueblo Reservoir. “The inspections are critical to help keep our waters from becoming infested.”
Stiegelmeier, along with the Dillon Ranger District and CPW, are optimistic they can locate the necessary dollars to keep up mandatory inspections before boats launch into Green Mountain Reservoir. They are looking to the Bureau of Reclamation, which owns and manages the dam there, to take on the burden of these costs, while also still searching for other proceeds.
“We are doing our best to find money for these programs,” said Jackson. “If the funding doesn’t come through, then, like other locations, we’ll have to rely on educating boaters, signs and really getting the word out through websites and social media. Otherwise, we’ll just have to close the area to boating, and we don’t want to do that.
“We haven’t given up and we’re still beating the bushes for help,” he added, “and still looking at options here in Summit County. We’re doing what we can.”
It rained so much in 2015, that you would expect another stampede of tumbleweeds by this time.
But that hasn’t happened.
There’s not a whole lot of rolling and tumbling going on.
“We’ve seen less, but we’ve had a lot in the pastures,” said Gary Walker, whose 63,000acre ranches border Fort Carson in northern Pueblo County. “My biggest problems are from Fort Carson and the prairie dog towns.”
Walker thinks a combination of more moisture, the timing of the rains and grazing contributed to a decline in the Russian thistle, the primary tumbleweed culprit.
Typically, the plants can grow up to 5 or 6 feet before breaking off and blowing in the wind. During the drought of 2011-13, they clogged ditches, skirted up against fences and blew into piles across most of Southeastern Colorado. In some areas, there were stacks up to the eaves of houses.
But there has been a lull this year.
“We’ve seen some, but with the winds we’ve had in recent weeks haven’t created the big piles we were seeing,” said Bruce Fickenscher, rangeland specialist for Colorado State University Extension. “In Crowley County, we mowed them and grazed them more. There have been some places where the weeds blow in, but they’re staying put, more than in the past few years.”
Walker said the plants grew with deeper roots, and also credits more cattle with cropping them closer to the ground earlier.
“In the past, when we were moving more cattle, there were fewer tumbleweeds,” Walker said. “When we get back to a more normal deal, we’ll be able to graze more cattle.”
But the natural conditions also play a role.
“By and large, it’s because of the way the rains came and the size of them,” Fickenscher said. “The weeds provided some protection for the native plants underneath. With Russian thistle and kochia, the taproot is deep and brings nutrients up.”
As long as the moisture continues, the tumbleweeds might not be as big a problem.
“We’re sitting better this year than we have been in a while,” Fickenscher said. “After a couple years of rain, we have more moisture in the subsoil.”
BASALT – Anglers, and almost certainly fish, can sense how much water is running down a river at any given time.
Last summer and fall, for example, some fly-fishermen who regularly wade in the Fryingpan River below Ruedi Reservoir thought there was too much water flowing out of the reservoir, as the river was running at 275 to 300 cubic feet per second. At that level, the river can be hard to cross in places.
Flows were up in the Fryingpan last year because a record amount of water was being released from Ruedi for the benefit of the 400 or so remaining Colorado pikeminnow living in 15 miles of the Colorado River between Grand Junction and Palisade.
Yet there still wasn’t enough water in the river for the pikeminnow last summer, despite a total 24,412 acre-feet of water released from Ruedi and sent down the Fryingpan, Roaring Fork and Colorado rivers. The “fish water” sent out of Ruedi last summer and fall may have helped the native fish struggling to survive in the heavily depleted Colorado River, but it still wasn’t enough on many days in August, September and October to reach the target flow level of 1,240 cfs set by biologists.
The same water sent downstream to make ancient fish in the Colorado River happier made veteran anglers on the Fryingpan River crankier. A similar scenario may play out again this summer, as up to 27,412 acre-feet of “fish water” is poised to be released from Ruedi this year to benefit the fish in the Colorado. On its way down, the water could cause late summer and early fall flows to rise again in the Fryingpan to 250, 300 or 350 cfs.
“My perfect flow for the ‘Pan, where everything is gravy, dry-fly fishing is perfect, and older people can get around, is 220 cfs,” said Marty Joseph, manager of Frying Pan Anglers. “Three hundred cfs is on the high side, especially for the older guys.”
A big part of “wadability” is “crossability,” or whether someone can get across the river to fish a better hole without the water rising above their waist and sweeping them off their feet.
“There are a lot of spots on the river, especially where I like to fish, where its crossable at 250 cfs with a client,” Joseph said. “But at 300 cfs, you can’t cross at that same spot.”
Last year’s flow, especially the steady 300 cfs that ran down the ‘Pan in late September and early October, caught the attention of many of his regular clients.
“We do get most of our experienced guys at the end of season, and a lot of them are older, and a lot of them are very particular, and they’ve been coming here for 10 or 15 years, and then all of a sudden they see this hike in the flows, and they’re having trouble with that,” Joseph said.
At least 10 of his clients wrote letters to him complaining about the high flows, and those letters recently were sent to the Colorado Water Conservation Board, which has a role in sending fish water out of Ruedi.
“We enjoyed our time at Taylor Creek cabins again this fall,” wrote one client to Frying Pan Anglers, “but, I should let you know that fishing was not very good attributed to the very high flows (300 cfs) in the Frying Pan (sic) River. These flows prevented us from wading in many areas of the river we are accustomed to fish. This was disappointing and frustrating.”
Frying Pan Anglers is one of the two larger fly-fishing guide services in Basalt. The other is Taylor Creek Fly Shops.
An economic analysis commissioned in 2014 by the Roaring Fork Conservancy found that anglers spend $3.3 million a year on fly-fishing trips to Basalt, factoring in their total spending from fishing equipment to guides to lodging.
A survey included with the analysis found that “wadeable flows on the river” was the second highest concern of visiting anglers after “insect hatches.” Of those surveyed, 37 percent said they would spend more days on the Fryingpan if the number of days when the river was flowing over 250 cfs was reduced.
But the flow levels out of Ruedi could be going up in the future.
There are three types of water released each summer and fall from Ruedi, a major storage reservoir for the Colorado River Basin opened in 1968 with a capacity of 102,373 acre feet. The first is a base flow, which in the absence of other water is 110 cfs. On top of that can be a fairly steady flow of “fish water” released at a rate that has varied over the last five years from 100 to 189 cfs. Last year, the flow rate of the fish water from Ruedi did not go above 175 cfs.
And on top of the layer of fish water can be a relatively thin layer of “contract water.” That’s water released in accordance with contracts the federal Bureau of Reclamation, which built the reservoir, has with 30 different owners. These pools of stored water are not often released, but the contracts do range from as little as 15 to much as 12,000 acre feet and collectively total 39,000 acre feet, so there is potential for significant future releases.
The dam manager working for the Bureau of Reclamation looks for the sweet spot on the Fryingpan and tries to deliver enough fish and contract water to meet demands while also keeping the river at a level that works for anglers. But that may be harder to do in the future, as there is more fish water than ever in Ruedi, and all of the available contract water has been sold, which means more people may call for it to be released, especially in the late summer and fall.
Officials with the U.S. Fish and Wildlife Service value water in Ruedi because it only takes two days for it to get to the critical reach where the pikeminnows and other endangered fish enjoy “feeding, breeding and sheltering.”
Over the years, officials have developed a pool of 15,412.5 acre feet of fish water in Ruedi. Then last year, the Colorado Water Conservation Board gave Fish and Wildlife another pool of water by leasing 12,000 acre feet from Ute Water Conservancy District, a water provider in Grand Junction.
Ute Water bought 12,000 acre feet of water in Ruedi in 2013 for $15.6 million to use as a back-up supply. It’s the biggest pool of contract water in the reservoir. And rather than leave it there, Ute Water entered into a lease with the CWCB to use it as fish water in 2015.
The CWCB, in coordination with Fish and Wildlife, then released 9,000 acre feet of the 12,000 acre-foot pool in September and October. It would have released more if not for its self-imposed limitation of flows not to exceed 300 cfs.
Ute Water plans to lease 12,000 acre feet to the CWCB again this year to send down the Fryingpan River and on to the Colorado River to benefit the fish. Between the existing 15,412.5 acre feet of fish water in Ruedi, that could bring up releases to 27,412.5, which the ancient native fish might appreciate.
Big, old fish
The Colorado pikeminnow, which is considered an indicator species for ecosystem health in the 15-mile reach, “evolved as the main predator in the Colorado River system,” states a 1999 programmatic biological opinion, or PBO, that guides recovery efforts for the fish.
“It is an elongated pike-like fish that during predevelopment times may have grown as large as 6 feet in length and weighed nearly 100 pounds,” the PBO states.
One pikeminnow with a radio tag was tracked swimming up the Colorado River nearly 200 miles from Lake Powell to the 15-mile reach above Grand Junction between April and September 1982, a year of very high flows.
Another endangered fish, the humpback chub, likes to live in deep fast-moving water. About 1,800 to 1,900 wild native chub are still making a go of it in the Black Rocks and Westwater sections of the Colorado, downstream from Loma.
Two other species, the razorback sucker and bonytail, have had a tougher time over the years, although hatchery-bred suckers are now said to be doing fairly well.
Of AF and CFS
To make up for low flows in the Colorado where the fish live, a total of 1.3 million acre feet of water since 1998 has been sent downstream from regional reservoirs. Of that total, 329,032 acre feet came out of Ruedi and flowed down the Fryingpan. On its way, the water has apparently helped, not hurt, the trout stream, but it has compromised wadability.
Complaints about flow levels have been recognized in previous environmental reviews on the impacts of storing and releasing fish water in Ruedi. And the benchmark to try and hit was 250 cfs.
But a recent modeling effort by Colorado Parks and Wildlife suggested 300 cfs was also an acceptable wadability level, and that level was used last year to guide releases on the Fryingpan.
“We have done some surveys in the past, and using modeling, came up with 300 to 350 cfs is where you significantly lose wadablity in the river,” said Kendall Bakich, a wildlife aquatic biologist with Colorado Parks and Wildlife. “But angler experience is a little different than what a model can say, so that’s where that 300 target came from.”
But on March 21, after reading the letters to Frying Pan Anglers, officials from the CWCB and the Fish and Wildlife Service said at a meeting in El Jebel that they will try to keep releases to the 250 cfs level this summer.
“Our board said that staff should work with the Bureau of Reclamation and angling interests to try and accommodate to the extent practicable angling concerns so that releases of water under the water lease agreement shall not cause the flows to exceed 250 cfs,” said Ted Kowalski, a section chief of the CWCB, referring to the CWCB’s recent approval of renewing the lease with Ute Water for the 12,000 acre feet of water.
It’s not a firm cap, though, and if necessary to meet the goals of the endangered fish program, releases could go to 300 cfs, and the river to 350 cfs after tributary flow is factored in.
Joseph at Fryingpan Anglers said the fishing wasn’t bad at 300 cfs, and that experienced guides can still find good spots to wade with clients. But Joseph has his concerns.
“My worry is this year they say 300 is acceptable and next year it’s going to be 350, and two, four, five years, it is going to 400 cfs,” Joseph said. “They’re slowly just going to keep moving on it.”
That’s also a concern of some local officials.
“One of the fears that we’ve had from the very beginning here, and one these days it’s going to come true, its that the Fryingpan is going to be converted from a gold medal trout fishery, with a occasional high releases, to a sluiceway that does basically nothing but deliver water downstream,” said Mark Fuller, the director of the Ruedi Water and Power Authority, which recently sent comments on the issue to the CWCB.
Fuller and regional water managers understand the value of working to keep the endangered fish alive in order to avoid enforcement of the Endangered Species Act.
“The 500-pound gorilla in the room is the PBO,” said Larry Clever, general manager of Ute Water, referring to the 1999 programmatic biological opinion.
The PBO requires that progress be made on sustaining the endangered fish. If not, an extensive environmental reviews known as “section 7 consultations” may be required under the ESA for all new or improved water projects on the upper Colorado River system.
“If those four endangered fish don’t make it, everybody has a section 7, for everything,” Clever said. “And, oh, we did one on a pipeline expansion. It cost $2.4 million. If the PBO goes south, we’re all in trouble.”
The Upper Colorado River Endangered Fish Recovery Program has been managing regional efforts to see what can be done for the fish both in the spring, when peak flows of at least 15,660 cfs are important to the fish, and in the late summer and early fall.
The goal is to stabilize populations through a variety of methods, including river flows, removing predatory non-native fish that eat young native fish and improving native fish passage around diversion dams.
As the 2016 runoff season approaches, water managers up and down the Colorado River are poised to again coordinate, via a weekly conference call, the release of fish water from reservoirs in the upper Colorado River basin.
They’ll do so for the sake of the remaining 400 adult Colorado pikeminnows, and their optimistic offspring, who desire at least 810 cfs of water in the fall, if it is a dry year, and 1,260 cfs if it is a normal year.
And for visiting anglers, they’ll also work to keep flows in the Fryingpan near 250 cfs.
Editor’s note: Aspen Journalism and the Aspen Daily News are collaborating on coverage of rivers and water. The Daily News published this story on Sunday, March 27, 2016.
The Tamarisk Coalition announces they recently received two grants on the behalf of the Desert Rivers Collaborative that will greatly help their cause. Tamarisk officials say grants from the Colorado Water Conservation Board and the Bacon Family Foundation, totaling more than $200 thousand, will allow the coalition to continue streamside restoration efforts in the Grand Valley.
It is projected that approximately 70 acres of additional riverside habitat will be restored, thanks to $175 thousand from the Colorado Water Conservation Board and $30 thousand from the Bacon Family Foundation. The funding will be used to pay different crews and contractors to use native plantings for re-vegetation and remove tamarisk, an invasive plant from the Eurasia region, as well as Russian olive, a thorny shrub and small tree that have overtaken a lot of riverside area.
In addition, the funding will tremendously aid in reducing wildfire risk and improving river function, soil conditions, and water quality, and ultimately improve our local habitat for fish and wildlife.
“The overall goal is to improve riparian health here in the Grand Valley, and it’s a continuation of projects that have been going on for several years,” says Shannon Hatch with the Tamarisk Coalition.
Funding from the Bacon Family Foundation will also allow the hiring of an intern to assist with project mapping, maintenance efforts, data management, technical assistance, community outreach, and engagement.
Invasive quagga mussels at Lake Powell. Photo courtesy NPS.
Early detection and response, partnerships across jurisdictions seen as critical measures
The spread of invasive species has been identified as the second-leading cause of extinctions among all plants and animals worldwide — and the problem is getting worse in the era of global trade. Just a few months ago, scientists warned that North American amphibians are at risk from an invasive fungus. White-nose syndrome, which has wiped out millions of bats, may have also spread to the U.S. from Europe.
Click here to read the report. Here’s the executive summary:
In 2001, the U.S. Department of Agriculture approved the release of a biological control agent, the tamarisk beetle (Diorhabda spp.), to naturally control tamarisk populations and provide a less costly, and potentially more effective, means of removal compared with mechanical and chemical methods. The invasive plant tamarisk (Tamarix spp.; saltcedar) occupies hundreds of thousands of acres of river floodplains and terraces across the western half of the North American continent. Its abundance varies, but can include dense monocultures, and can alter some physical and ecological processes associated with riparian ecosystems.
The tamarisk beetle now occupies hundreds of miles of rivers throughout the Upper Colorado River Basin (UCRB) and is spreading into the Lower Basin. The efficacy of the beetle is evident, with many areas repeatedly experiencing tamarisk defoliation.
While many welcome the beetle as a management tool, others are concerned by the ecosystem implications of widespread defoliation of a dominant woody species. As an example, defoliation may possibly affect the nesting success of the endangered southwestern willow flycatcher (Empidonax traillii extimus).
In January 2015, the Tamarisk Coalition convened a panel of experts to discuss and present information on probable ecological trajectories in the face of widespread beetle presence and to consider opportunities for restoration and management of riparian systems in the Colorado River Basin (CRB). An in-depth description of the panel discussion follows.
The panel concluded that as the tamarisk beetle moves into the Lower Colorado River Basin (LCRB), the selection of management actions to support a transition to a healthy riparian system will depend on the unique suite of characteristics of each sub-basin and the goals of basin managers.
The panel emphasized the importance of basin-specific planning, the necessity of monitoring and inventorying to inform management, and that adaptive management practices will be essential for success relative to varying goals. The panel developed a framework to assist managers in selecting appropriate management strategies and identified future research needed to further inform restoration approaches and management decisions.
Just because there hasn’t been as much talk about tamarisk lately doesn’t mean the invasion is over. Now, talk has begun again, but the message has changed.
Eradication is out; control is in.
While tamarisks, or saltcedars, are watergulpers, a fully grown tree uses only about 20 gallons a day, not 200 gallons as mistakenly was often reported in the past.
And trees should be taken out for a reason, and with a plan, not just because they are bad invaders.
Those messages have been conveyed twice in the last week by the Tamarisk Coalition to area conservancy districts. Based in Grand Junction, the group incorporated in 2002. The group works with other organizations to improve habitat, not just wipe out saltcedars.
“In a nutshell, what we do is help people restore rivers. We’re focused on that,” Stacy Beaugh, executive director of the Tamarisk Coalition, told the Southeastern Colorado Water Conservancy District board last week. “You can’t just cut them down and walk away.”
She assured the Southeastern board, which took the lead in earlier tamarisk removal programs for the Arkansas Valley, that Southeastern Colorado remains a high priority.
A few days later, the Lower Arkansas Valley Water Conservancy District heard from Rusty Lloyd, program director with the Tamarisk Coalition.
Lloyd explained that the group no longer is concerned with completely removing the trees, many of which were purposely planted for erosion control. But it supports efforts to remove pockets of the plant where possible and natural controls such as beetles to knock back the numbers.
“The beetle can weaken the plants, and some plants don’t come back,” Lloyd said. “It seems to be doing its job, but it’s sporadic.”
Lloyd said there are water quantity and quality benefits from removing tamarisk, but the purpose for any program should look at other issues such as improving wildlife habitat. A plan should be in place to replace tamarisk with more beneficial species.
“There are lots of invasive species we are concerned with,” Lloyd said. “We don’t blindly advocate people tearing out plants. You need to have a purpose.”
Past efforts to remove tamarisks have not always worked and sometimes cleared the way for other invasive species to take hold.
“We learn as much from our failures as we do from our successes,” Lloyd said.
Tamarisk leaf beetle
Tamarisk leaf beetles at work
2014 Tamarisk leaf beetle distribution map via the Tamarisk Coalition