Viewing the Status of Virginia’s Environment Through the Lens of Freshwater Fishes

We summarize a range of topics related to the status of Virginia’s freshwater fishes, their reflection of environmental quality, and their contribution to human wellbeing. Since 1994 the list of extant Virginia fishes has lengthened from 210 species to 227 species, mostly due to taxonomic reorganizations. Virginia’s list of Species of Greatest Conservation Need currently contains 96 fish species, predominated by darters (32 species) and minnows (28 species). Increasing trends in species rarity and threats to fishes suggest that Virginia’s aquatic environment is becoming less hospitable for fishes. Prevailing anthropogenic threats to fishes include agriculture, urban development, mineral extraction, forestry, and power generation; emerging threats include introduction of nonnative species and climate change. Agency assessments of Virginia’s streams, rivers, and lakes indicate that over 40% of them are impaired and that dozens of these waterbodies have fishes that, if consumed by people, contain harmful levels of mercury and polychlorinated biphenyls. Multiple state agencies are responsible for managing Virginia’s freshwaters and fishes to achieve objectives related to recreation, conservation, and environmental health. We close with a discussion of the challenges and opportunities associated with conserving Virginia’s diverse fish fauna and identify several research, management, and outreach actions that may enhance conservation effectiveness

Population Viability Analysis for Endangered Roanoke Logperch

A common strategy for recovering endangered species is ensuring that populations exceed the minimum viable population size (MVP), a demographic benchmark that theoretically ensures low long-term extinction risk. One method of establishing MVP is population viability analysis, a modeling technique that simulates population trajectories and forecasts extinction risk based on a series of biological, environmental, and management assumptions. Such models also help identify key uncertainties that have a large influence on extinction risk. We used stochastic count-based simulation models to explore extinction risk, MVP, and the possible benefits of alternative management strategies in populations of Roanoke logperch Percina rex, an endangered stream fish. Estimates of extinction risk were sensitive to the assumed population growth rate and model type, carrying capacity, and catastrophe regime (frequency and severity of anthropogenic fish kills), whereas demographic augmentation did little to reduce extinction risk. Under density-dependent growth, the estimated MVP for Roanoke logperch ranged from 200 to 4200 individuals, depending on the assumed severity of catastrophes. Thus, depending on the MVP threshold, anywhere from two to all five of the logperch populations we assessed were projected to be viable. Despite this uncertainty, these results help identify populations with the greatest relative extinction risk, as well as management strategies that might reduce this risk the most, such as increasing carrying capacity and reducing fish kills. Better estimates of population growth parameters and catastrophe regimes would facilitate the refinement of MVP and extinction-risk estimates, and they should be a high priority for future research on Roanoke logperch and other imperiled stream-fish species

A Long-Term Study of Ecological Impacts of River Channelization on the Population of an Endangered Fish: Lessons Learned for Assessment and Restoration

Projects to assess environmental impact or restoration success in rivers focus on project-specific questions but can also provide valuable insights for future projects. Both restoration actions and impact assessments can become “adaptive” by using the knowledge gained from long-term monitoring and analysis to revise the actions, monitoring, conceptual model, or interpretation of findings so that subsequent actions or assessments are better informed. Assessments of impact or restoration success are especially challenging when the indicators of interest are imperiled species and/or the impacts being addressed are complex. From 1997 to 2015, we worked closely with two federal agencies to monitor habitat availability for and population density of Roanoke logperch (Percina rex), an endangered fish, in a 24-km-long segment of the upper Roanoke River, VA. We primarily used a Before-After-Control-Impact analytical framework to assess potential impacts of a river channelization project on the P. rex population. In this paper, we summarize how our extensive monitoring facilitated the evolution of our (a) conceptual understanding of the ecosystem and fish population dynamics; (b) choices of ecological indicators and analytical tools; and (c) conclusions regarding the magnitude, mechanisms, and significance of observed impacts. Our experience with this case study taught us important lessons about how to adaptively develop and conduct a monitoring program, which we believe are broadly applicable to assessments of environmental impact and restoration success in other rivers. In particular, we learned that (a) pre-treatment planning can enhance monitoring effectiveness, help avoid unforeseen pitfalls, and lead to more robust conclusions; (b) developing adaptable conceptual and analytical models early was crucial to organizing our knowledge, guiding our study design, and analyzing our data; (c) catchment-wide processes that we did not monitor, or initially consider, had profound implications for interpreting our findings; and (d) using multiple analytical frameworks, with varying assumptions, led to clearer interpretation of findings than the use of a single framework alone. Broader integration of these guiding principles into monitoring studies, though potentially challenging, could lead to more scientifically defensible assessments of project effects

Simple Nudges for Better Password Creation

Recent security breaches have highlighted the consequences of reusing passwords across online accounts. Recent guidance on password policies by the UK government recommend an emphasis on password length over an extended character set for generating secure but memorable passwords without cognitive overload. This paper explores the role of three nudges in creating website-specific passwords: financial incentive (present vs absent), length instruction (long password vs no instruction) and stimulus (picture present vs not present). Mechanical Turk workers were asked to create a password in one of these conditions and the resulting passwords were evaluated based on character length, resistance to automated guessing attacks, and time taken to create the password. We found that users created longer passwords when asked to do so or when given a financial incentive and these longer passwords were harder to guess than passwords created with no instruction. Using a picture nudge to support password creation did not lead to passwords that were either longer or more resistant to attacks but did lead to account-specific passwords

Monitoring of Endangered Roanoke Logperch (\u3ci\u3ePercina rex\u3c/i\u3e) in Smith River Upstream from the Philpott Reservoir on U.S. Army Corps of Engineers Property near Martinsville, Virginia

The purpose of this study was to continue annual monitoring of Roanoke logperch (Percina rex), an endangered fish, in the Smith River immediately upstream from Philpott Reservoir. This river reach is owned by the U.S. Army Corps of Engineers (USACE), which must ensure that appropriate actions are undertaken to aid in recovery of logperch. Monitoring of fish abundance and habitat conditions provides a means for assessing the species’ status and its responses to USACE management actions. The Roanoke logperch is a large darter (Percidae: Etheostomatinae) endemic to the Roanoke, Dan, and Nottoway River basins of Virginia and North Carolina, where it occupies third- to sixth-order streams containing relatively silt-free substrate (Jenkins and Burkhead, 1994). Because of its rarity, small range, and vulnerability to siltation, the Roanoke logperch was listed in 1989 as endangered under the U.S. Endangered Species Act (ESA) (U.S. Federal Register 54:34468-34472). Within the Dan basin, Roanoke logperch have long been known to occupy the Smith River and one of its largest tributaries, Town Creek (Jenkins and Burkhead, 1994). Logperch also recently were discovered in other tributaries of the Dan River, including North Carolina segments of the Mayo River, Cascade Creek, Big Beaver Island Creek, Wolf Island Creek (William Hester, U.S. Fish and Wildlife Service, personal commun., 2012). Within the Smith River, Roanoke logperch are present both upstream and downstream from Philpott Reservoir, a hydroelectric and water storage project owned and operated by the USACE. Although logperch have not been observed in the reservoir itself, the species is relatively abundant in a free-flowing, ≈ 2.5-km-long segment of Smith River upstream from the reservoir on USACE property (Lahey and Angermeier, 2006). This segment is bounded on the downstream end by the lentic conditions of the reservoir and on the upstream end by White Falls, a natural waterfall that presumably allows fish passage during all but the lowest streamflows (Roberts and Angermeier, 2009; fig. 1). The ESA stipulates that USACE must ensure that its actions do not jeopardize Roanoke logperch and ensure that appropriate actions are taken to aid in the recovery of Roanoke logperch. USACE recognized that additional information was needed to assess compliance with these stipulations, including data on baseline population levels, habitat availability, and potential threats to the species on USACE property. USACE therefore contracted with Virginia Tech (VT) and the U.S. Geological Survey via the Virginia Cooperative Fisheries and Wildlife Research Unit (VCFWRU) to continue ecological monitoring that was initiated in a pilot study in 2005 (Lahey and Angermeier, 2006). The VCFWRU is jointly sponsored by the U.S. Geological Survey, Virginia Tech, Virginia Department of Game and Inland Fisheries, and Wildlife Management Institute. This final report summarizes results of biological monitoring performed by VT and the VCFWRU in 2011, and compares these data to data collected during 2006–2010 (Roberts and Angermeier, 2011). Where appropriate, a comparison was made to data on Roanoke logperch collected previously in the study reach (Lahey and Angermeier, 2006) and in the upper Roanoke River (Roberts and Angermeier, 2011). This work was performed under the auspices of VT’s Institutional Animal Care and Use Committee (IACUC) protocol 11-035-FIW. Specifically, the following objectives were addressed: • Estimate population density of Roanoke logperch on USACE property; • Measure and map by suitability class the distribution of habitat suitable for Roanoke logperch in the project area; • Assess water quality relative to Roanoke logperch habitat in the project area; • Use the data on logperch abundance, habitat suitability,and water quality to test the general validity of corre-lates of logperch abundance from other locations; • Identify opportunities and threats related to protecting and enhancing Roanoke logperch habitat; and • Provide suggestions on the necessity and scale of future studies and monitoring related to logperch in and near USACE waters

Standardized Methods for Sampling Fishes in Streams of Panama

The purpose of this chapter is to outline methods for standardized sampling of stream fishes in Panama. For the purposes of this document, we define “stream fishes” to mean any fish species (classes Petromyzontida, Chondrichthyes, Sarcopterygii, and Actinopterygii) that spends any portion of its life in freshwater streams that are shallow enough to be sampled by wading. This definition includes species that are lifetime residents in fresh water, as well as those that migrate between fresh and salt water over the course of a lifetime (i.e., anadromous, catadromous, and amphidromous species). We anticipate that the methods described herein can be applied to any wadeable stream in Panama to produce comparable data on fish distribution and abundance