We assessed the effectiveness of the western pearl mussel (Margaritifera falcata, Gould, 1850) as a bioindicator of aquatic system health. Fifty-years ago a large dredge mining operation for columbite-tantalite ores [(Fe,Mn)(Nb,Ta)₂O₆] disturbed a substantial portion of the Middle Fork of the Salmon River headwaters in Idaho. The disturbance likely increased concentrations of dissolved metals at the time. To evaluate the potential long-term impacts, if any, concentrations of Fe, Mg, Mn, and Zn in shell and soft tissues of western pearl mussels, collected from five reaches in Bear Valley Creek, were analyzed. We quantified the partitioning and bioaccumulation with respect to age of the four metals in the shell, gills and mantle, and remaining soft tissue of the western pearl mussel. Overall, gills and mantle had higher concentrations of Fe, Mg, Mn, and Zn than the remaining soft tissue and shell. Bioaccumulation with respect to age was not uniform among elements or mussel material. We did not detect significant metal accumulation along an upstream gradient approaching the historic dredge site. Metal accumulation downstream did not appear to be in response to the physical disturbance or potential enhancement of dissolved metals during dredging activities in the mid-1950s. However, no mussels were located within the historic dredging zone. Possible reasons for no mussels in the dredging zone are discussed, but not reconciled. We conclude that using freshwater mussels and a water quality assessment might provide a useful approach to biological monitoring of past and current exposures to essential and non-essential elements.

Protection Island National Wildlife Refuge, WA, is home to the majority of breeding seabirds and harbor seals found in the Puget Sound/San Juan Island area. The island consists of a high central plateau flanked by bluffs on the north and south and by low points on the southwest and east. We analyzed the physical and vegetational changes in Protection Island from the 1860s to 1999, an interval spanning an early period of agricultural use followed by intensive subdivision into building lots and then conversion to a refuge. During that time span Kanem Point on the southwest had shortened and Violet Point on the east had lengthened. The tall northwest bluffs, which experienced rapid erosion early last century, had steepened and stabilized. Little change had occurred on the northeast and southern bluffs or on the bluffs over the points where many seabirds nest. On the upper plateau, forested areas had shrunk sharply due to fires and lot development but were recovering. Dunes had migrated to the northeast and stabilized. Introduced species dominated the grasslands on the upper plateau. By contrast, native species continued to dominate Violet Point. Native dune grass, however, was expanding on Violet Point and tended to exclude most other species. Richness, percent cover, and diversity of introduced species on Violet Point were significantly lower than on the upper plateau, while richness and percent cover of native species were higher. Continued prevalence of native species on the point may be a result of a plant community adapted to the low, rocky substrate and frequent disturbance by nesting gulls.

Determining the gender of American martens (Martes americana) and fishers (M. pennanti) from track plate stations would significantly augment the information currently gathered from this simple and inexpensive survey method. We used track-plate impressions collected from captured individual martens and fishers of known gender to develop methods to distinguish the gender from tracks. We collected marten tracks from two subspecies M. a. sierrae (tracks n = 54, individuals m = 12, f = 8) and M. a. humboldtensis (tracks n = 109, individuals m = 10, f = 9). We developed a model for martens which performed extremely well (91–100%) using only total track length. For fishers, we collected 64 tracks (from 7 males, 17 females) and developed a 3-variable model, using interdigital pad height, interdigital pad width, and total track length, which correctly classified 98.6% of the tracks. We evaluated track quality on 129 sheets of contact paper collected during summer (dry-season) and 137 sheets collected during fall (wet-season); 100% of dry season compared to 51% of wet season sheets had suitable quality tracks. Gender discrimination of Martes tracks can be used to investigate gender differences in distribution and habitat (associations), but the generality of these findings to other populations is undetermined.

An increase in ungulate population size potentially exposes aspen suckers, saplings, and trees to increased use. This study examined how stem height and girth influenced the selection of stems by ungulates for browsing, rubbing, and gnawing, and reconstructed the history of ungulate use for the study area. Transects were run through each of three aspen clones growing in southwestern Montana to determine height, circumference, and the surface area from which bark was totally and partially removed by rubbing and gnawing. Stems 20–250 cm tall were browsed. Stems 2–13 cm diameter were preferentially selected for rubbing and gnawing. The area of totally removed bark on dead saplings was twice the area of removed bark on live stems of similar diameter, suggesting that bark removal played a major role in the death of some stems. Based on an analysis of stem height and age, ungulate browsing was inferred to have increased from a light-to-moderate level to an intense level in 1991. The depth of scars was used to date scarring events. An increase in rubbing and gnawing was determined to have occurred about 1985. We concluded that elk were primarily responsible for the observed impacts. The combined effect of rubbing, gnawing, and browsing affects a broader span of ages compared to the effect of browsing alone. If prescribed fire is used to rejuvenate aspen stands, the resulting young stems should be protected from heavy browsing, rubbing and gnawing until they reach about 13 cm diameter and have grown out of the browse zone.

Freshwater mussels are thought to have declined in abundance and changed in species composition in the Columbia River in recent years. We surveyed the 118 km of river between Vernita Bridge and Wallula Gap and found only two small aggregations of floaters (Anodonta spp.) and no western pearlshell mussels (Margaritifera falcata), a species which was formerly dominant in the river. One of the floater aggregations appears to have been nearly extirpated but may be recovering, while the other aggregation appears to be stable. Scattered individual floaters were also found in McNary Reservoir. Two populations of western pearlshell mussels were studied in the Clearwater River in Jefferson County, WA for comparison. The Clearwater populations were large, densely aggregated, of multiple size classes, and showed little evidence of mortality. Mussel tissues from each site were analyzed for lipid content and levels of arsenic, mercury, and organochlorine pesticides. The highest lipid content and mercury concentration were found in mussels from the Clearwater River. Arsenic concentration and organochlorine pesticides were highest in mussels in the Columbia River. Overall, the mussel aggregations within the Columbia River were small, scattered, and provided a marked contrast to the flourishing mussel beds in the Clearwater River. These results suggest that Columbia River mussels have both declined and changed in species composition over the last century.

Aerial surveys of elk have generally not been used to estimate elk abundance in western Washington primarily due to concerns over the highly variable detectability of elk in forested vegetation. The purpose of our study was to investigate the development and application of aerial sightability models to survey elk in forested habitats of the west-central Cascades. Survey units were delineated and surveyed from a helicopter. We used radio-tagged elk and logistic regression to model the influence of vegetation cover characteristics, elk group size, and activity on sightability of elk. Models were assessed using Akaike Information Criteria. The best model included elk group size and percentage of vegetative cover. These results indicate that when corrected for sightability, aerial surveys for elk may be a reasonable alternative for assessing elk abundance in wintering elk herds of the central Cascades.

To more effectively use ospreys as a biomonitoring tool and to better assess contaminant pathways, the diet of nesting ospreys (Pandion haliaetus) was studied along the lower Columbia and upper mainstem Willamette rivers by evaluating prey remains collected from wire baskets constructed under artificial feeding perches installed near nest sites and from the ground beneath natural feeding perches and nests. Prey remains from 1997–2004 on the Columbia River and 1993 (previously published) and 2001 on the Willamette River were evaluated and compared. Largescale suckers (Catostomus macrocheilus) were the predominate fish species identified in collections from the Columbia River (61.5% [84.3% biomass]) and Willamette River (76.0% [92.7% biomass]). Prey fish diversity, when based only on ground collections, was higher in the Columbia (2.45) than the Willamette river (1.92) (P = 0.038). Prey fish diversity in collections from the Willamette River did not differ between this study (2001) and previous study (1993) (P = 0.62). Fish bones recovered in wire baskets are likely more representative of osprey diet compared to bones recovered from the ground, because prey diversity was higher among basket samples compared to ground collections (wire basket diversity = 5.25 vs. ground collection diversity = 2.45, P = 0.011). Soft-boned salmonids (Oncorhynchus spp.), American shad (Alosa sapidissima), and mountain whitefish (Prosopium williamsoni) were probably underrepresented in collections obtained from the ground. Study results suggest that baskets provide a better method for assessing osprey diet than other indirect methods. These findings augment available osprey food-habits information and provide additional biological and ecological information to better assess potential impacts of various environmental contaminants on nesting ospreys.

The lodgepole pine dwarf mistletoe, Arceuthobium americanum, a common parasite found in western Canadian forests, causes significant yearly timber loss. The purpose of this work was to determine if dwarf mistletoe infection of lodgepole pine affects the anatomy and morphology of its needles. Needles were collected from infected, highly-broomed trees and from visibly uninfected (control) trees. Differences in the dimensions of the needles and vascular cylinder, fresh weight, number of stomata per unit surface area (density), size of stomata, stomatal area per unit surface area, and number of rows of stomata were quantified. Needles from infected brooms were shorter, thinner, and narrower with larger, more densely packed stomata.