An increasing threat to U.S. waterways is the establishment and spread of invasive and injurious fishes. A species may be designated by the U.S. Fish and Wildlife Service (USFWS) as federally “injurious” under the Lacey Act (18 U.S.C. 42) either if that species causes harm (injury) without establishing and spreading (not invasive), or if that species causes harm after establishment and spread (invasive). Species designated as injurious are prohibited from being imported, which is a highly effective way of preventing invasions by nonnative species. We developed a decision-support, risk assessment system to aid USFWS’s prioritization of species for injuriousness. Our system is based on USFWS’s evaluation criteria of a species’ potential injuriousness and consists of a semi-quantitative, rapid-assessment procedure called the Ecological Risk Screening Summary (ERSS) and a quantitative probability network model called the Freshwater Fish Injurious Species Risk Assessment Model (FISRAM). ERSS provides information on a species’ history of invasiveness elsewhere in the world, and on its biology and ecology, potential or known effects of introduction, global and domestic distribution, and climate associations, and provides conclusions on potential risk of invasiveness. FISRAM calculates expected probability of injuriousness as a function of species potential establishment, spread, and harm, based on probable effects on native species and ecosystems, suitability of climate and habitat in introduced areas, ease of dispersal and transport, and harm to humans. FISRAM is used to assess risk probability when ERSS categorizes invasion risk as uncertain. We calibrated and updated the probability structure of FISRAM using a data set of 50 species with known invasiveness outcomes. We demonstrate the use of these two models for risk assessment and decision-support in identifying and documenting species for potential risk management actions, such as listing wildlife as injurious under the Lacey Act.
Stream habitat restoration in the Entiat River, Washington, has increased juvenile Chinook abundance in pools with engineered logjams (ELJs); however, high spatial, temporal, and inter-species variation complicates distinguishing treatment effects between restored and unrestored habitat. Here we show that the scale of post restoration effectiveness monitoring can also be a confounding factor in such studies. In three stream reaches, we conducted snorkel surveys of (1) spatially randomized untreated habitat in which we also randomized survey area, and (2) restored (ELJ) habitat that included varying amounts of the surrounding stream area. Although we regularly observed more young-of-the-year Chinook salmon in restored than in unrestored habitat, this effect was very localized. After controlling for reach effects, fish density in untreated habitat was not affected by proximity to ELJs. Increasing the survey area increased total fish abundance, however, fish density decreased regardless of habitat type, indicating that ELJ structures did not necessarily increase fish abundance at the whole-reach scale. Specifically, increasing the survey area around a pool created by an ELJ by two to three times the restored pool area resulted in density measurements indistinguishable from unrestored habitat surveys. We conclude that whole-reach scale effectiveness monitoring surveys may give misleading results that dilute the effect of ELJs; therefore, monitoring should match the scale of specific restoration treatments.
Long-term conservation planning for diadromous fishes would benefit from a better understanding of both the role of connectivity among environments and habitat variability in the expression of life-history diversity. Most of the scientific knowledge on habitat fragmentation and connectivity has been developed in terrestrial systems in the discipline of landscape ecology. Research on habitat connectivity in aquatic systems (e.g., salmonid research that spans the spectrum of habitats from freshwater to the sea) is uncommon and largely focused on barriers to fish passage. Here, we present a review of the literature characterizing current research patterns on habitat connectivity within and among environments for Pacific salmon. We found this topic is still incipient: the literature is dominated by studies of freshwaters, with few articles focusing on habitat needs in estuary and marine systems. Pan-environment studies are rare, pointing to a gap in our understanding of complex habitat relationships that might be significant in the development of long-term conservation and restoration plans for Pacific salmon, particularly in light of the potential impact of climate change.
Growing up in a southern Oregon timber town in a family strongly rooted in logging, the U.S. Forest Service (USFS) has always been part of my life. The conflicts which embroiled the USFS during my youth are etched in my memory. I vividly remember when the northern spotted owl Strix occidentalis caurina was listed as federally endangered. Mills closed and parades of coffins rolled down the streets with proclamations that the end of federal timber harvest would spell the end of towns like ours. In college, I learned more about public land management for natural resource sustainability. Recognizing the importance of economics in environmental issues, I studied both environmental science and economics. Graduate degrees in fisheries (Ph.D.) and geography (M.S.) honed my expertise on aquatic ecosystems and their spatial context. Yet, my timber-town roots still color how I relate to the world. Understanding the relationships among ecological and economic values of fish, forests, and watersheds—and trying to find a balance—is a recurring theme in my work.
The success or failure of fish populations in rivers is intimately linked to a complex and interconnected series of ecological interactions. This complexity can make it difficult to predict how organisms within river ecosystems will respond to management actions and other environmental changes. To aid in solving this dilemma, we constructed a food web simulation model termed the Aquatic Trophic Productivity (ATP) model. The ATP model mechanistically links the success of fish populations to the dynamics of river food webs and the abiotic conditions that influence these webs. This report serves as a user manual for version 3.3 of the ATP model, which was designed to explore how river food webs and fish species, particularly Pacific salmon and trout, respond to management actions and other environmental changes. The report includes a discussion of the model’s origins, assumptions, structure, and application. Our primary goal is to provide users the background information needed to apply the model to research and management questions. Specifically, we describe how to parameterize the model and conduct simulations from the model’s user interface.
Identifying units of conservation of aquatic species is fundamental to informed natural resources science and management. We used a combination of mitochondrial and nuclear molecular methods to identify potential units of conservation of Westslope Cutthroat Trout Oncorhynchus clarkii lewisi, a taxon native to montane river basins of the northwestern United States and southwestern Canada. Mitogenomic sequencing identified two major lineages composed of nine monophyletic clades, and a well-supported subclade within one of these, largely delineated by river basins. Analyses of microsatellites and single nucleotide polymorphisms corroborated most of these groupings, sometimes with less resolution but demonstrating more complex connections among clades. The mitochondrial and nuclear analyses revealed that Pleistocene glacial cycles profoundly influenced the distribution and divergence of Westslope Cutthroat Trout, that this taxon crossed the Continental Divide in two separate events, and that genetically pure but nonindigenous fish were widely distributed. Herein, we recognize nine geographically discrete, cytonuclear lineages largely circumscribed by major river basins as potential units of conservation: (1) John Day; (2) Coeur d’Alene; (3) St. Joe; (4) North Fork Clearwater; (5) Salmon; (6) Clearwater headwaters; (7) Clearwater-eastern Cascades; (8) neoboreal, consisting of most of the Columbia upstream from central Washington,the Fraser in British Columbia, and the South Saskatchewan in Alberta; and (9) Missouri.
This case study was developed as part of a larger, interdisciplinary research project to assess the social, hydrological, and ecological effects of beaver-related watershed restoration approaches in rangeland streams of the Western United States. It is one of five case studies being undertaken to investigate the social context of beaver-related restoration in western rangelands. The Scott River basin in northern California is the first place in the state where watershed restoration using beaver dam analogues (BDAs, instream post and vegetation-weave structures that mimic natural beaver dams) has been tried. The project takes place on private lands and in streams where federal Endangered Species Act-listed southern Oregon/northern California coast coho salmon (Oncorhynchus kisutch) spawn and rear in fresh water before migrating out to the ocean. It started in 2014 as an initiative of a local community group, the Scott River Watershed Council, with technical support from a National Oceanic and Atmospheric Administration scientist. Project goals include improving instream habitat for coho salmon to promote population recovery, improving surface water flows, raising groundwater levels, reducing stream channel incision, and demonstrating the value of BDAs as a restoration tool in California. To date, 10 BDA structures have been built at five sites on streams running through private property in the Scott River basin, and more are planned. Beavers have been active, or have taken over maintenance of BDAs, at all sites. Because this is the first project in California to use this restoration approach, and because the BDAs are being built in critical fish habitat, the project has been undertaken on an experimental basis. It has entailed a large learning curve on the part of the Scott River Watershed Council and federal and state regulatory agencies, but over time the regulatory process for permitting BDAs has gotten easier, and stakeholders are working together to collectively find solutions to ongoing BDA-related challenges. Most of the private landowners involved are ranchers who also grow hay, and who have largely positive views of beavers and beaver dams, so long as they do not interfere with irrigation infrastructure. Monitoring data and interviews with stakeholders indicate that the BDAs are starting to achieve their goals, and are benefitting both landowners and fish, although impacts are localized because the project remains small in scale owing to its experimental status. The Scott Valley case offers important lessons learned for undertaking beaver-related restoration in a private lands context.