The English sole (Parophrys vetulus, family Pleuronectidae) is an abundant ground fish used as a sentinel of marine pollution in the inland marine waters of Washington and Oregon. We used 15 microsatellite loci to evaluate patterns of genetic variability within and among 17 collections of sole from coastal sites and within the southern Salish Sea. Over 470 alleles were identified in 15 loci, and high levels of genetic richness, as estimated by expected heterozygosity (H_E) and allele richness (A_R), were detected. Fish sampled from coastal areas at the northern end of our study area had the lowest values of genetic richness, in contrast to collections at the southern end. The level of differentiation among all collections was low: mean F_ST value was 0.0006. Nineteen comparisons had statistically significant F_ST values (mean F_ST of 0.0029) and involved comparisons involving three locations associated with urban areas (Port Gardner [Everett, WA], Sinclair Inlet [Bremerton, WA], and Commencement Bay [Tacoma, WA]). A statistically significant, but weak, isolation-by-distance pattern was seen in the five coastal collections over 1,100 km of coastline. In the Salish Sea collections, the pattern of differentiation was patchy and marked by several distinctive collections in close proximity to urban areas. The pattern of differentiation in the Salish Sea parallels differences seen in ecotoxicological characteristics of the English sole that inhabit separate urban embayments differing in pollution characteristics. Future work can focus on evaluating the stability and meaningfulness of this subtle variability in a time of local and global environmental changes.

In western North America, nonnative brook trout (Salvelinus fontinalis) frequently threaten native salmonids via competition and hybridization, so fisheries managers often implement eradication programs for conservation purposes. In conjunction with such programs, managers often construct population models to evaluate the effects of different management strategies designed to control the undesirable population, but such models require demographic data (e.g., age, growth, sex ratios, and survival), which are lacking for western brook trout populations. Brook trout were sampled from 12 alpine lakes and two streams in Idaho, with total length varying from 80 to 380 mm and age varying from 1 to 11 yrs. Across all waters, the von Bertalanffy growth parameters L∞ varied from 231 to 490 mm (mean = 345 mm) and K varied from 0.15 to 0.76 (mean = 0.37). Survival estimates, constructed from age-length keys, were corrected for streams with mark-recapture data; for alpine lakes, corrections were made via gill net selectivity data. Survival varied from 0.30 to 0.56 (mean = 0.45), and except for one waterbody, estimates were minimally affected by correcting for capture efficiency. The proportion of the population that was male varied from 0.34 to 0.75 (mean = 0.53). Our results indicate that brook trout population vital rates in Idaho were similar to those observed in their native range, and were surprisingly similar between alpine lake and stream environments.

Increasingly large high-severity wildfires in dry forests of the western United States have led to concern about how best to regenerate new forests after wildfires. Harvesting fire-killed trees, burning woody debris, and tree planting are commonly used reforestation strategies. This study evaluated the effects of a novel forest restoration approach that involved masticating un-merchantable dead trees and spreading the woody debris generated across the site to prevent erosion from the 2007 Angora Fire in Lake Tahoe, California. Woody material covered 82% of the site after treatment, with an average depth of 6.6 cm, and volume of 190 tonnes per hectare. We found that this treatment reduced shrub regrowth, compared to an untreated area nearby, and that shrub regrowth was inversely related to fuel depth. Seven years after the fire, shrub cover averaged only 50% on treated plots compared to 92% on untreated plots. The tallest shrubs averaged 69 cm in height on the treated site compared to 114 cm on nearby untreated sites. Tree seedlings planted on the treated site averaged 141 cm in height, well above the height of the shrubs. Advantages of this approach include controlling erosion while reducing drought stress, reducing the potential for weed introduction, and reducing the need for herbicide to control shrub competition. Although leaving a layer of woody material where new trees have been planted does constitute a fire hazard, so too does a vigorous shrub layer. Managers should consider and weigh these factors when deciding on a post-fire reforestation strategy.

Freshwater mussels in the western US are under-studied compared to their eastern cousins, and no western species receive federal protection. Mussel distribution throughout Oregon's rivers and streams is poorly documented, and there are limited historical records to inform assessments of whether, and by how much, current populations may have declined. We launched a long-term project to characterize freshwater mussel populations throughout the Willamette River basin. Surveys were conducted in the mainstem Willamette River and a major tributary, the Middle Fork Willamette, during three years. A two-stage sampling process was used; transects were surveyed qualitatively, and then 0.25 m² quadrats were placed randomly in transects for quantitative surveys. Mussels visible at the substrate surface were counted using viewing scopes and snorkeling, and scuba diving in deeper water. To facilitate detection of juveniles (≤ 3.50 cm long) and calculation of the burial factor, some quadrats were double sampled; mussels visible at the surface were counted, then the substrate was excavated to a depth of 10 to 20 cm, and all mussels (surface and buried) were counted and their shell length measured. Dense western pearlshell (Margaritifera falcata) populations were found at all locations, but they differed greatly in length class structure, density, and presence of juveniles. Some sites also contained small numbers of floaters (Anodonta spp.), and notably, a single western ridgemussel (Gonidea angulata) was found in a highly urbanized reach. These surveys provide baseline data on the current status of several freshwater mussel populations in the Willamette River basin.

Dam removal often shows positive effects for many fish species, especially migratory species. In contrast, information regarding the effects on less migratory species is lacking. The Elwha River, Washington had two hydroelectric dams removed from 2011 to 2014, which resulted in the loss of two reservoirs. Because of glacial history, the Elwha River system has a depauperate freshwater fish fauna, including just two sculpin species (coastrange sculpin [Cottus aleuticus] and prickly sculpin [C. asper]). Both species exhibit a similar migratory life history strategy, which includes a planktonic larval stage that drifts downstream to a nursery area (e.g., lake, large river, or estuary), followed by an upriver movement pattern. Due to these characteristics, Elwha River dam removal and loss of the reservoirs may have had important effects on these two sculpin species. We sampled sculpins with longitudinal electrofishing surveys in 2018 and 2019 to evaluate their current distribution, relative abundance, and body size. These metrics were generally similar to other river systems in the Pacific Northwest, with fewer and larger migratory sculpins upstream. Additionally, we compared our findings to pre-dam surveys. After dam removal, sculpins in upstream reaches were less abundant and had a smaller range of sizes. This suggests the population characteristics of sculpins in the Elwha River has changed, but it is unclear how indirect effects, such as anadromous salmonid (Salmonidae) increases, may influence their overall abundance. This study also provides a baseline to monitor sculpin population changes in the future.

Each winter, thousands of bald eagles (Haliaeetus leucocephalus) from across western North America migrate to Pacific Northwest rivers to feed on the carcasses of post-spawning chum salmon (Oncorhynchus keta). However, declining salmon populations and impacts of climate change are reducing the availability of salmon carcasses as a wintering food source for eagles. The ability of eagles to adjust to these impacts is crucial to their survival, and their responses are currently unknown. I hypothesized that eagles are responding by redistributing to non-river habitat in search of alternative food sources. Specifically, I examined the redistribution of over-wintering eagles from river habitat to nearby agricultural areas in response to seasonal declines in carcass availability. Over two consecutive winters, I conducted weekly eagle surveys on a 30-km stretch of the Nooksack River and a 22.5-km stretch of farmland northwest of the river. I examined the association between salmon carcass distribution and eagle abundance on the Nooksack River, and evaluated the temporal relationship between eagle abundance on the Nooksack River versus neighboring farmland. I found a strong negative association between eagle abundance on the river versus adjacent farmland, and observed eagles primarily concentrated near dairy farms and waterfowl rafts. My results suggest that eagles are responding to declining carcass availability by redistributing to non-river habitat in search of alternative food sources, and that a substantial fraction may migrate to agricultural areas.

In well-established flowering plant invasions, floral phenotypes that do not attract pollinators are predicted to be eliminated through natural selection. We explored this hypothesis in the invasive plant species Scotch broom (Cytisus scoparius), which has yellow flowers frequented by a diverse community of bee species, as well as red-tinged flowers that are predicted to be pollinated at a significantly lower rate. We predicted that plants with the red-flower phenotype will have fewer flowers visited, produce fewer seed pods per flower, and produce fewer seeds per pod than the yellow-flowered type. To investigate this, we measured the proportion of flowers pollinated for red- and yellow-flowered phenotypes, observed the number of seed pods produced per flower, and counted seeds per pod. Although we found lower pollination in the red-flowered phenotype, we did not see differences in female fitness. Scotch broom is an invader predicted to be limited in fecundity by the rate of pollinator visits and would be expected to lose phenotypes that attract fewer pollinators. We found the persistence of a less-attractive phenotype, likely because the reduction in male fitness is not paired with a reduction in female fitness.

Woodpeckers require trees and snags with decayed wood in order to excavate nest and roost cavities, and interior wood hardness is considered an important factor determining where a woodpecker can create a cavity. In most ecosystems, saprophytic fungi are responsible for the decay and softening of wood, and are thought to be important in providing soft wood for woodpecker cavity excavation. We conducted a study of cellulose-degrading enzymes in the wood surrounding woodpecker nest cavities. We measured wood hardness, percent wood density loss (PWDL), and activity of cellobiase (an extracellular fungal cellulase that degrades cellulose) within wood surrounding the nest cavities of the northern flicker (Colaptes auratus), black-backed woodpecker (Picoides arcticus), white-headed woodpecker (Dryobates albolarvatus), and hairy woodpecker (D. villosus) in Oregon and Washington. We found that mean wood hardness was significantly lower, and cellobiase and PWDL were significantly higher, at nest cavities than controls for each woodpecker species. Wood hardness was higher and cellobiase lower at nests of black-backed woodpecker than northern flicker, but did not differ among the other woodpecker species. Our results suggest that increased amounts of cellobiase result in softer wood due to the increased decay caused by higher fungal enzyme activity and that measuring cellobiase can be used to estimate wood decay without directly measuring wood hardness. All four woodpecker species selected nest substrates with softer wood and higher fungal enzyme activity than controls. This supports findings from previous studies of the importance of saprophytic fungi for woodpecker cavity excavation.

Genetic analyses have become increasingly powerful, more readily available to biologists, and have made ever more degraded DNA potentially useful. Single nucleotide polymorphisms (SNP) are a relatively new “class” of markers that show promise for use with degraded or archived samples. We sequenced a panel of 298 SNPs from Chinook salmon (Oncorhynchus tshawytscha) tissue in three comparative studies to determine the effect of DNA quality at sampling, time in archive, and tissue type and preservation method on SNP genotyping success using logistic regression. The first study evaluated pristine DNA from live adults sampled at three hatcheries and archived up to 6 years. The second study compared samples from carcasses with varying levels degradation (i.e., condition) and archived up to 15 years. The third study compared heart and fin samples preserved either in ethanol or on paper from carcasses with varying levels of degradation and processed within 6 months. Genotyping success for fresh tissue did not decline over the 6-year archive period at two of the three hatcheries, suggesting sample handling techniques may be more influential than time in archive. Genotyping success of archived carcass samples depended more on carcass condition than time in archive. Heart tissue genotyped consistently more often than fin samples from all but poor condition carcasses. Based on these results, we make tissue-sampling recommendations for different intended purposes. We also provide simple, post-collection sample handling procedures that can increase genotyping success regardless of tissue or preservation method.

A deformed rib from a Columbian mammoth (Mammuthus columbi) was found among more than 100 mammoth bones excavated from an alfalfa field at the Tonnemaker Hill Farm in the Frenchman Hills north of Royal City, Grant County, Washington. The mammoth remains were deposited within fine-grained Missoula flood sediments sometime after 16 ka. We performed a detailed examination of the rib, including computerized tomography imaging, and investigated the possible etiology of the deformity. The deformity consists of hypertrophic bone formation localized toward the distal (sternal) end of the rib. The circumference of the lesion is nearly twice that of the medial circumference of the rib diaphysis. This lesion is consistent with an incompletely healed fracture or a fracture nonunion with pseudarthrosis (false joint) formation. Gross examination and computerized tomography scan images of the proximal aspect of the rib, as well as cursory inspection of the other skeletal remains, have yet to reveal definitive evidence of other bony abnormalities. We surmise, therefore, that this fracture was the consequence of blunt force trauma in a healthy animal. To our knowledge, this is the first report of a rib fracture with incomplete healing or false joint formation in a M. columbi individual in the Pacific Northwest. We suspect the incidence of rib fractures among M. columbi was greater than the Pacific Northwest literature suggests and encourage examination of existing collections for evidence of similar findings. The incidence and frequency of such injuries may provide insight into M. columbi behavior.