Malheur Lake Modeling, a PhD

Written by James Pearson/Photos provided by James Pearson

As I wrap up my Ph.D I wanted to give a brief description of my work, a quick synopsis of my results, and describe how these results have changed our thinking about restoration in Malheur Lake.

Malheur Lake is large (≈ 19,600 ha) and shallow (average depth ≈ 0.58 m; max depth ≈ 1.26 m), and therefore to better understand how Malheur Lake should function I first tried to get a basic understanding of shallow lakes in general. Shallow lakes exist in either a clear or turbid state (i.e. Alternative Stable States Theory), with the clear state characterized by an abundance of aquatic macrophytes, diverse aquatic biota, low water column nutrients and phytoplankton biomass, whereas the turbid state is characterized by the opposite. These two distinct states are maintained by reinforcing (positive) feedback loops that pull the system towards one of the two states (clear or turbid).

In order to better understand the current turbid state of Malheur Lake, I used a mechanistic modeling approach to the different factors maintaining the current state of turbidity. The two agents suspected in maintaining the turbid state in Malheur Lake are: 1) benthic (bottom) foraging by non-native Common carp (Cyprinus carpio) and 2) wind resuspension of lake-bed sediments.

I first simulated the non-native Common carp (hereafter “carp”) population in Malheur Lake and focused on controlling carp via removal efforts aimed at suppressing carp biomass below the desired 50 kg/ha threshold. These simulations indicated that individual carp removal actions would likely fail due to compensatory density dependent responses (recruitment, mortality, growth) within the carp population. Simulations further demonstrated that combinations of two or all three active removal methods could reduce the biomass below the desired threshold, however the carp reduction rate would have to be maintained ≈40% at each life-stage, in perpetuity. Furthermore, adding hydrologic variability into the carp population model ultimately demonstrated that the carp population in Malheur Lake is more affected by the interactions within the population brought on by environmental fluctuations (lake area) than the human capacity to impose mortality rates via removal efforts.

Ultimately these results demonstrated that focusing management actions solely on the reduction of carp would likely be ineffective, and thus investigations of other mechanisms helping to maintain the turbid state was necessary. Therefore, I shifted the modeling to investigate the deleterious effects of the wind and wave energy, with simulations ultimately demonstrating that the wind-wave energy is a major driver of the turbid state, and that restoration efforts in the form of wave reduction barriers may be used to decrease the suspended sediment concentrations and increase the water clarity. Collectively, modeling results reinforce the notion that future restoration actions in Malheur Lake must be more broadly focused (i.e. systems perspective) and guided by the principles of the alternative stable state theory.

Whereas our modeling demonstrated that human-constructed wave reduction barriers may be used to decrease the overall SSC in Malheur Lake, there are other means of attaining the same ends. For instance, facilitating the establishment of emergent vegetation in the lake could reduce wind-driven SSC, with results expected to vary among locations based on results of this work. Work in other systems has demonstrated that emergent vegetation can act to dissipate wave energy in shallow lakes, thus decreasing the winds forces and limiting resuspension. The rigid stems of emergent vegetation can dissipate the height of peak turbulence, and thus lower the frequency of resuspension events (increased wave dissipation with stem density). Furthermore, I was unable to find a study that has demonstrated deleterious effects of carp on emergent vegetation, yet there are a large number of studies demonstrating the negative effect of carp on submergent vegetation both directly and indirectly. Therefore, unlike submergent vegetation that is adversely affected by carp, emergent vegetation should be able to persist even in the presence of carp, and thus provide shelter from the forces of wind and potentially promote favorable growing conditions for submergent vegetation during years in which the carp biomass is low either via carp management actions or natural population fluctuations brought on by environmental variability.

A representation of % change in turbidity under the influence of wind reduction.

The potential ability for emergent vegetation to diminish the deleterious effects of wind-wave energy, and the fact that emergent vegetation is seemingly not effected by the presence of carp, led me to consider why there is currently very little emergent vegetation present in Malheur Lake. Historical documents describe how antecedent hydrological events are important in determining the contemporary lake state. For instance, during the prolonged flooding in the 1980’s, Malheur Lake increased to a lake area of ≈ 51,500 ha with a max depth of ≈ 4.4 m, exceeding all previously instrumented recordings. These floods inundated the robust emergent vegetation stands for an extended period of time and under depths at which they may not have been able to survive, and thus once the flooding subsided, Malheur Lake was void of emergent vegetation except for a narrow ring around the lake. Therefore, it has been hypothesized that the loss of emergent vegetation, specifically the rooted structures that act to secure the sediment is why Malheur Lake is now highly susceptible to wind resuspension.

To eventually overcome the momentum of the reinforcing feedback loops pulling Malheur Lake towards the turbid state, results of my research indicate that a large perturbation is needed, and the individual scenarios that I modeled will likely in themselves be ineffective at shifting the lake back to the clear state because their forces are too small in the context of Malheur Lake. Therefore, a more large-scale transformative effort that includes carp management, wind fetch reduction, and transplantation of emergent vegetation will likely be necessary to not only flip the current state, but also to maintain the clear state in perpetuity.

Working Together For the Birds

Written by Janelle Wicks/Photos by Janelle Wicks

Early this spring the Friends of Malheur NWR announced that we were committed to installing vent screens on all four of the vault toilets located on Malheur National Wildlife Refuge. These vault toilets are located at Buena Vista, Krumbo Dam, Krumbo Reservoir and P Ranch.

Vault toilets mitigate odors from the underground storage tank by venting air through a pipe in the roof. This pipe, while malodorous and uninviting to us, can look enticing to animals that nest, roost or otherwise utilize cavities in trees and rocks, such as birds and small mammals. When the animals enter the vent and tumble into the tank below, they’re often unable to escape and sometimes perish in the dark, damp, confined space.

Thankfully for wildlife, there is a tidy fix for this messy problem. The Teton Raptor Center, widely credited as being among the first groups to address this issue, teamed up with staff from the U.S. Forest Service to create screens that fit over the vent pipes, keeping wildlife out while maintaining proper air flow. In 2011 the Teton Raptor Center launched a public-awareness campaign called the Port-O-Potty Owl Project; they’ve since helped to distribute and install thousands of these screens on vault toilets on public lands. Friends of Malheur is currently looking to raise money to purchase these screens for the four vault toilets currently installed at Malheur Refuge.

Vault Toilet Screens by Peter Pearsall; Malheur Musings, March 2020

In the March issue of the Malheur Musings newsletter we called for support for this endeavor and several of you, our Friends, answered. Foremost in this response were several individual donations and one $200 contribution from the East Cascade Audubon Society, With these funds we purchased the screens, associated hardware and set about adding this project to our Spring Cleaning stewardship work party which was to take place mid-March.

With the impacts of Covid-19 forcing the closure of the Crane’s Nest Nature Center & Store we also cancelled all volunteer activities. Governor Kate Brown’s Stay Home, Save Lives order combined with Non-essential travel restrictions, which remain in place still, required that we get creative about following through on projects without the helpful hands of our Friends volunteers.

Luckily for us, the Refuge shares a partner with the Friends in Portland Audubon. Teresa Wicks, Portland Audubon’s Eastern Oregon Field Coordinator and FOMR Executive Director Janelle Wicks set out to support one another in the time sensitive task of installing these four vault toilet screens. In addition to this, it was just about nesting season for American kestrels and Portland Audubon still had one more nest box to install.

We are grateful for the collaborative nature of partnership that exists withing the Refuge community here at Malheur. Without this we may have had to put off such an important task, not to mention miss out on an opportunity to see the views from atop a vault toilet.

Words of Water

Written by Linh Nguyen/Photos by Alan Nyiri

As a Professional Science Masters student intern from Oregon State University, my program requires an internship consisting of a meaningful research project that will serve the organization I work with. In constructing the framework of my project for this internship, Ms Wicks and I settled on a project  that is a visually engaging outreach display of quotes about the Refuge, we call it the Words for Water project. I would be reading books, and collecting quotes about the landscape of the refuge through time from multiple sources . 

The more I read about the refuge, the more I admire the rich history of the land. It was first the home of the Burns Paiute Indian Tribe. Seasonally, the Wadatika Band lived in caves, and near shorelines, where they hunted for fish and game, and gathered seeds and fruits among other things. The first recorded encounter of the Paiute Tribe with the remaining part of the world started with Peter Skene Ogden, a fur trapper from Hudson’s Bay. In their expedition, they passed Malheur, Mud, and Harney lakes, and when they entered the Harney Valley on September 6th 1845, Jesse Harritt, a diarist in the party praised: 

“As we advanced this morning the beautiful scenery increased; this valley is one of the most sublime places I ever saw; […] the soil is rich and beautifully set with fine grass, intermingled with patches of sage; the mountains to the north in places are thinly set with pine and cedar timber.” 

From 1859 to 1865, the U.S. Military and Oregon Volunteers also explored the Harney Basin, Lt. Joseph Dixon wrote of the area north of Malheur Lake from the crossing of the Silvies River (June 1859): 

“to the base of the mountains, a distance of about 18 miles, the country is a beautiful level valley, covered with a luxuriant growth of bunch grass, wild pea vines, and red clover, interspersed with fields of camas on a rich soil abundantly watered by numerous mountain streams…. This wide savannah or grassy meadow section is abundant; antelope, deer, elk, and several species of grouse, prairie chickens, ducks, geese, etc.” 

As can be imagined from these two excerpts, the area was beautiful and thriving vigorously, with rich biodiversity. 

In June 1872, Peter French departed from the Sacramento Valley with 1,200 head of cattle, a Chinese cook, and a dozen vaqueros. The Donner und Blitzen River was enticing to French, as Giles French, his biographer noted, “This valley, surrounded by sloping hills on which grass grew as high as a man’s stirrups, looked like cattle heaven to Peter French and he thought it could be just that if range and cattle were properly managed.” French and his men altered the sagebrush steppe and diverted the natural flow of the river by flooding the lower Donner und Blitzen, to promote the growth of meadow grass. Giles French, wrote: 

“His irrigation projects … held the water of Malheur Lake at a lower level, causing more dry land between the water and the meander line. The meander line is a surveyed line which follows the outline of some given stream, lake, or swamp. Such lines were later to have profound impact on the life of Peter French.”

Indeed, the contest between French and homesteaders who moved onto lands below the meander line is the cause to his murder in 1897. 

You can see how, having begun this internship during these unprecedented times, reading these historical accounts is my only opportunity to come to know the landscape of Malheur National Wildlife Refuge and the surrounding Harney Basin. There is a deep and dynamic history that is inextricably connected to the land. Small windows to this world of water and land can be found among these words. I found my favorite quote among all these books.

“One of the greatest values of our national wildlife refuges is that they preserve nature unspoiled and provide a place where persons can go to repair the damage done by the rattle and clang of civilization. Nature aids us in placing human relations in proper perspective”

(Jackman and Scharff 1968:65). 

Youth Artist in Residence Program

Art Gallery & Competition

The Friends of Malheur National Wildlife Refuge, in conjunction with the Harney County Migratory Bird Festival, sponsored the annual Artist-in-Residence (AIR) program. Wildlife Refuge Specialist Carey Goss and a local artist spent eight days traveling to schools in Burns, Diamond, Frenchglen, Crane, Drewsey, Riley, Double O, and Fields. The program combines history, art and science and served almost 600 students in grades K-8.

This year, in the face of Covid-19, we are modifying this program to engage our rural students through a virtual gallery of their artwork. We hope you enjoy the creative genius of our local youth. Enjoy!

This program has annual costs of approximately $1,200. We are proud to share this with you and hope that you will consider supporting the Youth Artist in Residence Program.


Spring Water Management

Written by Debby De Carlo/ Photo by Peter Pearsall

Sandhill Cranes are passing through, white-face ibis, curlew and other waterbirds have arrived at Malheur National Wildlife Refuge, and the refuge is ready for the breeding birds. Managing water for best uses at the Refuge looks straightforward in the Comprehensive Conservation Plan. But there are new or different variables every year, USFWS Wildlife Biologist Alexa Martinez explained. “We make our decision(s) based on the fields and ponds that have the highest priority for wildlife benefit and then to our haying program which also provides stubble habitat for other species of wildlife as well as hay for livestock. It may vary from year to year due to the amount of water we receive and how fast it comes down from the snowpack on the Steens. Usually the manager, biologist and maintenance crew get together to make a final decision by March 1, with a water plan for the year.”

One big challenge, said Maintenance Supervisor Ed Moulton, is moving the water from the southern end of the Refuge to the northern end. “We use canals, ditches and dams,” Moulton noted. “It’s very labor intensive. If it comes off the mountain gradually, that is good. When it comes off fast, that is not good, but we take it when we can get it.”

There are ponds, called impoundments, that hold the water when there is a good amount of precipitation in early spring. Last year was a good water year, with a good snowpack and plenty of precipitation in the spring, though the water did come off the mountain a little fast, creating a bit of a headache for water managers on the refuge. 

By moving surface water throughout the Refuge by way of canals, ditches and dams, and by using flood-irrigation to create wet meadow habitat, there is diverse wetland habitat for nesting birds and for the millions of birds stopping over to rest as they migrate to more northern nesting grounds. 

A benefit of spreading water across the desert landscape is the creation of wet meadows, or haying fields. Besides providing nesting habitat for meadow dependent species like Bobolinks, neighboring ranchers cut the hay in the fall, hay they can feed to their cattle. The resulting stubble provides forage for spring migrating birds as they fly north.

Throughout the Silvies Floodplain, and wetland habitat around the refuge, some area ranchers participate in the Harney Basin Wetlands Initiative, coordinating with conservation groups, land management agencies, and other stakeholders to maximize conservation benefits for wildlife and production benefits for agriculture. They primarily achieve these objectives through flood-irrigation, similar to the surface irrigation used by the Refuge According to Portland Audubon’s Eastern Oregon Field Coordinator and biologist Dr. Teresa Wicks, flood irrigation is time consuming and labor intensive for these ranchers,” she said. Using wells for irrigation can be less labor intensive, but may not be sustainable in the desert. “As groundwater is pumped out of the ground for agriculture, the water table has been drawn down. As the groundwater table has been drawn down, surrounding wells and groundwater dependent ecosystems have potentially been affected. “Conversion from flood-irrigation, using surface water, to sprinkler irrigation, using groundwater would remove habitat for migrating waterfowl and waterbirds,” Dr. Wicks added. “Surface water is important. For example, in years where less water makes it to Harney Lake, the lake becomes more saline. Brine shrimp and alkali flies can’t survive in water that is too saline. So in particularly low water years, this important food source for migrating and breeding shorebirds may not be available.” “Water management for ecosystems, the economy, and society are why collaboration with all the partners in the region is so important and will continue to be if predictions of future widespread drought, and increased climatic variability in the West are accurate,” she added.

Looking east from 205 towards Malheur Lake in late February 2020.
Photo by Janelle Wicks

Due to high amounts of water entering the system throughout 2019 parts of the refuge and surrounding areas are seeing benefits with remnant surface water from the previous year. Mid-February saw the spread of surface water from the lake to the Narrows wayside, which had been long hoped for over the last few years. Now, geese, ducks, and even pronghorn are visiting this oasis and are visible from the pullout on 205. We can only imagine the sheer magnitude of similarly vibrant and thriving habitats across the Refuge’s 187,000 acres.