Assessment of waste grain densities to aid waterfowl conservation in the Klamath Basin of northeastern California and southeastern Oregon

Post-harvest waste seed from cereal grains is a major dietary component of waterfowl in the Klamath Basin in northeastern California and southeastern Oregon, a region that plays host to over a million waterfowl annually. Understanding food abundance is critical to local waterfowl management, therefore we conducted a study in 2008 to investigate waste grain densities in barley, oat and wheat fields. We used hierarchal mixed effect models to assess several factors that may affect waste grain densities post-harvest. We also compared the effects of residue management practices to measure the effect of these treatments. To understand the scope of post-harvest practices, we conducted a weekly road survey to document treatments applied to fields in our study area. We found that, region, best explained the variance of post-harvest waste grain in barley fields, where the Tule Lake region had 89% greater densities than Lower Klamath. Neither harvester age or baling affected waste grain in oats fields. In wheat fields, the model containing region and lodging ranked highest, where the Tule Lake region had 66% greater waste densities than Lower Klamath and lodging increased waste grain by 70%. Burning did not reduce waste grain in barley or oat fields. Chisel-disking reduced waste grain by 94% in wheat fields, compared to post-harvest. Our field treatment survey found that 70% of barley fields were untreated while 18% were disked and 13% were burned and flooded. We estimated that 82% of oat fields were burned post-harvest while 18% were burned and flooded. In wheat, 61% of fields were left untreated, while 16% were disked, 8% were chisel-plowed and 7% were flooded post-harvest. Flooding and burning occurred primarily on National Wildlife Refuges while disking, chisel-plowing and post-harvest irrigation occurred solely on private properties. Our results indicate that reducing tillage treatments would boost accessibility of cereal grain food resources to waterfowl in the Klamath Basin, and incentives to flood grain fields on private properties should be considered for the same purpose when and where possible.

A new species and range extensions for three other species of pebblesnails (Lithoglyphidae, Fluminicola) from the upper Klamath basin, California–Oregon

This is the fifth in a recent series of papers on the poorly known western North American pebblesnail genus Fluminicola (Caenogastropoda, Lithoglyphidae). Herein we clarify the taxonomic status of the currently undescribed pebblesnail fauna in the upper Klamath River drainage (UKL) based on morphologic evidence, and mitochondrial DNA sequence data from 58 UKL collection localities. We describe one new species (F.klamathensis) from eight UKL localities which is differentiated by mtDNA sequences and unique penial morphology, and document range extensions to the UKL for three species from closely proximal drainages (F.fresti, F.modoci, F.multifarius). Fluminicolafresti was found at a single locality along the western edge of upper Klamath Lake. Fluminicolamodoci and F.multifarius are widely distributed in the UKL; both species exhibit marked morphologic variation yet are relatively little differentiated genetically in this basin.

Population Viability of Endangered Lost River Sucker and Shortnose Sucker and the Effects of Assisted Rearing

The Lost River Sucker Deltistes luxatus and Shortnose Sucker Chasmistes brevirostris are two narrowly endemic fish species in the upper Klamath Basin of southern Oregon and northern California. Both species have been federally listed as endangered pursuant to the U.S. Endangered Species Act since 1988 because of dramatic declines in abundance and distribution. In Upper Klamath Lake, Oregon, both species have only recruited a single cohort to the adult populations since that time. Most individuals in this population are at or older than the expected life span of the species. Consequently, the U.S. Fish and Wildlife Service and the Klamath Tribes have initiated assisted rearing efforts to stabilize the population. However, it is unclear how quickly these populations might become extirpated and how assisted rearing might alter population trajectories. We modeled the potential for extinction and recovery of the populations of endangered Lost River Sucker and Shortnose Sucker in Upper Klamath Lake. We simulated population trajectories over the next 50 y with a stochastic population viability assessment approach. Projections indicate that if population trajectories do not change, the Shortnose Sucker population may decline by 78% to number < 5,000 in 10 y and become completely extirpated within the next 30 (18.6% probability) to 40 y (99% probability). The two Lost River Sucker populations have a greater likelihood to remain extant after 50 y, with only 1% probability of extinction given our scenarios and assumptions, but the populations are likely to number fewer than 1,000 individuals. Our results also suggest that rearing of Klamath Lake sucker species in a controlled environment for augmenting the natural population will be effective in reducing extirpation probabilities over the next 50 y if survival to recruitment can be achieved, but a long-term effort of at least 40 y will be required. The necessity of long-term augmentation to ensure population persistence in the absence of natural recruitment underscores the urgent need to determine and address the causes of recruitment failure in the wild.

Of Time and the Wetland

At the oldest of Arcata’s treatment wetlands, it’s now possible to walk on water. Over three decades of filtering sewage, Arcata’s wetland cells have developed floating mats of dead cattail stems and leaves underlain by living roots, resilient enough to support a person’s weight. The short journey across Treatment Wetland 3 is a strange experience, like walking on a soggy trampoline. Water seeps through the cattail mat and into footprints. On a February day, a dense maze of brown cattail stems stretches twelve feet above the wetland’s surface, their shaggy brown seedheads waving in the breeze. A stroll across the treatment wetland is as close as a modern American can hope to get to the feel of the floating tule islands that William Finley camped on in the upper Klamath Basin in 1905, and that crowded California’s unspoiled marshes before the Gold Rush. The floating mats in Arcata were created by accident when the city’s treatment plant operators increased the depth of the treatment marshes, part of an effort to improve their declining performance. To their surprise, the dense growth of cattail rose off the bottom and continued to thrive, roots dangling in the water. The wetlands have aged. “Arcata’s is the grandmother municipal treatment wetland,” says David Austin, an environmental engineer with CH2M Hill who specializes in treatment wetlands design. Austin remembers studying the Arcata wetlands as a student at University of California at Davis in the 1990s. “It was a pioneering system. Now it’s an old design— one that wouldn’t be used today.” In 2016, three decades after Bob Gearheart’s unconventional marshes began cleaning Arcata’s sewage, the city’s wastewater plant faced a crisis. During the cold rains of winter, the system often failed to perform to the standards set in its discharge permit. Every part of the plant had aged to the point where its performance was in decline. At the headworks, the two giant Archimedes screws that push raw sewage uphill through a coarse screen had been running for decades; their metal housings were rusting away.

A laboratory-calibrated model of coho salmon growth with utility for ecological analyses

We conducted a meta-analysis of laboratory- and hatchery-based growth data to estimate broadly applicable parameters of mass- and temperature-dependent growth of juvenile coho salmon (Oncorhynchus kisutch). Following studies of other salmonid species, we incorporated the Ratkowsky growth model into an allometric model and fit this model to growth observations from eight studies spanning ten different populations. To account for changes in growth patterns with food availability, we reparameterized the Ratkowsky model to scale several of its parameters relative to ration. The resulting model was robust across a wide range of ration allocations and experimental conditions, accounting for 99% of the variation in final body mass. We fit this model to growth data from coho salmon inhabiting tributaries and constructed ponds in the Klamath Basin by estimating habitat-specific indices of food availability. The model produced evidence that constructed ponds provided higher food availability than natural tributaries. Because of their simplicity (only mass and temperature are required as inputs) and robustness, ration-varying Ratkowsky models have utility as an ecological tool for capturing growth in freshwater fish populations.