Concerned stakeholders in various nations are investigating stock enhancement with hatchery supplementation as one of several strategies to restore imperiled burbot (Lota lota L.) populations. In other intensively studied species, the use of genetic markers for parentage-based tagging (PBT) has become an important tool for evaluating the ecology of hatchery-wild fish interactions. Our objective was to determine if microsatellites previously developed for studies of burbot phylogeography could be multiplexed for effective PBT. A total of 14 microsatellite loci were multiplexed in four panels and tested for PBT efficacy in a hatchery population of burbot. An exclusion-based test involving 123 anonymous offspring and 51 known parent-pairs resulted in 97% of the progeny assigning to the correct parents. Due to modest genetic diversity in the broodstock population, a high false-assignment rate (19%) was observed when parental cross information was excluded from parentage analyses. While the existing set of burbot microsatellites can be multiplexed into effective panels for PBT, we recommend the development of additional microsatellite or single nucleotide polymorphism markers to improve exclusionary power.

Variable-retention (VR) logging practices provide an alternative to clearcutting, but much uncertainty exists on their effectiveness in maintaining biodiversity. We compared patterns of abundance of terrestrial gastropods in areas subjected to either clearcutting or VR treatments, in relation to an uncut control at six experimental sites in coastal British Columbia before and 2–4 years after logging. Gastropods sensitive to the logging treatments in most comparisons included Haplotrema vancouverense, Pristiloma stearnsii and P. lansingi (as a group), and Striatura pugetensis. Several generalist species showed no response to the treatments, and the abundance of two species (Punctum randolphii and Vespericola columbianus) increased in some logged treatments relative to the control. At sites where trees were retained in small groups (0.2–0.5 ha), the abundance of four species was depressed when compared to the control and pre-logging values. No differences among retention levels of 10%, 20%, and 30% were found. At a site where trees were retained in groups of different sizes, large groups (0.8–1.2 ha) were more effective in supporting sensitive species than were small groups (< 0.2 and 0.2–0.5 ha) and clearcuts. At a site where dispersed trees were retained, none of the logged treatments were equivalent to the control. No consistent patterns of higher abundance in the 30% retention level than in the 5% and 10% levels were found. The results contribute to the growing body of information on the complexity of responses of forest floor organisms to habitat modification by logging.

Non-native brook stickleback (Culaea inconstans) have inhabited Turnbull National Wildlife Refuge (TNWR) in Washington state since at least 1999. Their impact on aquatic habitats is unclear and is of concern as TNWR is managed for migratory waterfowl and the diets of waterfowl and brook stickleback overlap. This study compared the benthic macroinvertebrate communities of four TNWR lentic systems that contain brook stickleback with five lentic systems that are free of brook stickleback. Each lentic system was sampled once in each of three periods in 2012 (June through September). Timing significantly affected macroinvertebrate density in the lentic systems that do not have brook stickleback but not in those containing brook stickleback. Summed across all taxa and samplings, lentic systems without brook stickleback had nearly 10-fold higher macroinvertebrate density (4.24 L^-1) and significantly more macroinvertebrate taxa than did lentic systems with the non-native fish (0.49 L^-1). To determine whether brook stickleback could contribute to changes in macroinvertebrate communities, we conducted feeding trials under laboratory conditions. Brook stickleback were presented with macroinvertebrates from 10 abundant taxa; the fish consumed, on average, 89% of the macroinvertebrates and consumed individuals from each taxon. We found no evidence of gape-limitation in brook stickleback for the commonly-encountered size range of macroinvertebrates. These results indicate that brook stickleback may be partly responsible for the altered macroinvertebrate communities at TNWR and that these non-native fish are a substantial threat to the quality of aquatic habitats at TNWR and should be considered for classification as invasive in Washington state.

Freshwater mussels play an important role in stream ecosystems but are declining worldwide. The California floater (Anodonta californiensis, Lea 1852), formerly widespread throughout the Pacific Northwest, is listed as a federal species of concern and a candidate species for state listing in Washington (WA). Because freshwater mussels are obligate parasites on fish, conservation and restoration efforts require understanding specific host fish species. We found a previously undocumented population of A. californiensis in the upper Yakima River Basin in WA and determined its host fishes through a combination of laboratory and field studies. Two fish species, speckled dace (Rhinichthys osculus) and torrent sculpin (Cottus rhotheus), were confirmed as hosts for A. californiensis. Two fish species, three-spine stickleback (Gasterosteus aculeatus) and redside shiner (Richardsonius balteatus), were identified as hosts for A. californiensis in the laboratory portion of this study. Our results fill a significant data gap for building a successful conservation and restoration program by extending the known range of A. californiensis within the Yakima River Basin, and by identifying a suite of suitable host fishes for A. californiensis, including two that had not been previously confirmed as hosts. Our results can be incorporated into a management approach that focuses on the conservation and recovery of not only A. californiensis, but its host fishes as well.

Limited information exists on small mammal communities in industrial forests of northern California. Small mammal communities are important components of forest ecosystems and a better understanding of small mammal relationships to fine-scale habitat features in industrial forests can aid management. We developed overall and species-specific models to assess the relationships between small mammals and fine-scale (64 m²) habitat features (i.e., cover of shrub, forb, grass, rock, mineral soil, forest litter, downed wood, and trees). We also assessed fine-scale land cover category. We trapped small mammals from May to August of 2011–2013 in 65 stands using a web based trapping design that consisted of Sherman and Tomahawk live-traps. We captured 11 small mammal species with the most frequently captured species being Peromyscus spp. and California ground squirrels (Spermophilus beecheyi) in Sherman and Tomahawk traps, respectively. Pooled small mammal captures in Sherman traps were positively influenced by shrub cover at trapping locations. This relationship was also observed in Peromyscus spp. and Allen's chipmunk (Tamias senex). We captured more Peromyscus spp. and pooled small mammals when a trap was placed in retention rather than clearcuts. In Tomahawk traps, pooled small mammal captures were positively influenced by shrub cover and downed wood. We captured more California ground squirrels in clearcuts opposed to controls and found forest litter to negatively influence ground squirrel captures. Our findings emphasize the importance of fine-scale habitat elements, primarily downed wood, shrub cover, and retention patches on small mammal habitat use in industrial forests of northern California.

This study was conducted on the Kootenai River, Idaho to provide insight on sampling requirements to optimize future monitoring effort associated with the response of fish assemblages to habitat rehabilitation. Our objective was to define the electrofishing effort (m) needed to have a 95% probability of sampling 50, 75, and 100% of the observed species richness and to evaluate the relative influence of depth, velocity, and instream woody cover on sample size requirements. Sidechannel habitats required more sampling effort to achieve 75 and 100% of the total species richness than main-channel habitats. The sampling effort required to have a 95% probability of sampling 100% of the species richness was 1100 m for main-channel sites and 1400 m for side-channel sites. We hypothesized that the difference in sampling requirements between main- and side-channel habitats was largely due to differences in habitat characteristics and species richness between main- and side-channel habitats. In general, main-channel habitats had lower species richness than side-channel habitats. Habitat characteristics (i.e., depth, current velocity, and woody instream cover) were not related to sample size requirements. Our guidelines will improve sampling efficiency during monitoring effort in the Kootenai River and provide insight on sampling designs for other large western river systems where electrofishing is used to assess fish assemblages.

Five growth models were evaluated for their effectiveness in characterizing growth of an isolated population of bull trout, Salvelinus confluentus, undergoing a long term cessation of harvest (1994–2005) in the North Fork Clearwater River, Idaho, above Dworshak Dam. To explore the dynamics of growth in migratory bull trout, one of the models, the von Bertalanffy model, was also fitted based on age estimates derived from annuli and growth increments on pelvic fin ray sections for three juvenile outmigration age groups. Among five growth models evaluated, four models fitted to the age-length data described the fish growth for ages 3 to 11 comparably well. Only a model that exhibited positive growth acceleration as age progressed fitted the data less effectively. Growth was significantly (P < 0.001) related to the age of outmigration from natal streams (1–3 years). Migratory bull trout were found to reach maturation at ages 4–6; the common age-4 maturation was younger than most comparable studies. All mature fish studied reared for 2–3 years in downriver or reservoir habitat. As the adult population size has continued to increase since harvest closure in 1994, further research should be directed towards understanding the trade-offs between these increasing numbers of adult fish and growth, survival, migration, and maturation schedules.

Forests can be dissected or internally fragmented by anthropogenic linear clearings. Much research has focused on roads but in forests overlying oil and gas reserves, seismic lines (narrow exploration trails) also internally fragment forests and alter landscape structure. Seismic lines are of particular interest because they already exist in western North America and exploitation of future reserves may require new seismic line clearing over vast forest areas. An assessment was needed to compare their relative contribution to forest fragmentation against other more well-known linear forest clearings. This study was conducted across an area of 4022 km² of boreal forest in western Canada. Seismic lines directly occupied a relatively small area (1% of all land), but were five times longer than roads and rail lines. Seismic line density was more than twice that of roads, rail lines, power lines and pipelines combined and accounted for 80% of all edges. Seismic lines have the potential to indirectly influence more forest than all these other types of linear forest clearings. Seismic lines consistently decreased the size of forest patches, and increased the number of patches across spatial scales from 5.0–4900 ha but tended to have a greater impact at larger spatial extents. While roads are the most important agents of fragmentation in some forests, in forests where oil and gas reserves are exploited, seismic lines have the greatest impact on forest fragmentation.

Seagrass ecosystems are some of the most productive coastal habitats in the world. Eelgrass (Zostera marina) is an ecosystem engineer that provides important ecosystem functions and services. In 2010, the National Oceanic and Atmospheric Administration (NOAA) began construction of their Marine Operations Center-Pacific (MOC-P) in Yaquina Bay, Oregon; coupled with this were unavoidable habitat damages, and mitigation included the creation of a transplanted eelgrass bed. The purpose of this project was to assess the recovery of ecosystem structure and function within this transplanted bed using an ecosystem-based approach. Ecological indicators (e.g., eelgrass percent cover, faunal richness and abundance) and environmental variables (e.g., sediment and water quality parameters) were monitored over 12 months at the transplanted mitigation site and two reference sites. Each bed was observed to be unique in structure, predominately driven by physical setting. Eelgrass cover at the mitigation site remained unchanged and significantly lower than at reference sites; however, most faunal indicators within the transplanted eelgrass bed were comparable to those of existing eelgrass beds. During the first year post-transplant, the eelgrass bed within the NOAA MOC-P mitigation site remained stable and was observed to be adequately performing the functions associated with eelgrass ecosystems in the Pacific Northwest. Characterizing the transplanted bed with an ecosystem-based approach allowed us to accurately assess the site's progress toward mitigation goals and provide information important to management of the NOAA MOC-P mitigation site and future eelgrass mitigation efforts.