Habitat Preferences of the Eastern Hellbender in West Virginia

The Eastern Hellbender, Cryptobranchus alleganiensis alleganiensis, is a species of concern in West Virginia and is in need of management. An important component of conservation efforts will involve identifying suitable habitat for protection. The goal of this research was to locate populations and examine hellbender habitat preferences to help managers identify habitat for protection. Populations were located using rock turning surveys from May through November, 2006. Hellbenders may be sensitive to water chemistry, so the dissolved oxygen, pH, turbidity, specific conductivity, and water temperature were measured. Substrate composition may influence populations, so substrate was characterized with Wolman pebble counts. Crayfish relative abundance was measured because they are an important prey item. Mean habitat characteristics of sites where hellbenders were present and absent were compared with t-tests. Habitat variables were ordinated in princip al component analysis and examined in 2-dimensional ordination space to determine if sites where hellbenders were present grouped. Populations were found at 12% of sites, indicating that populations have declined in many streams. Hellbenders preferred sites with a large amount of gravel and cobble, cool water temperatures, low specific conductivity, and lower pH values. Gravel and cobble substrates may provide habitat for larval hellbenders and invertebrate prey items. Cool streams allow for more efficient cutaneous gas exchange. Low specific conductivity may indicate undisturbed conditions, suggesting hellbender populations were concentrated in less disturbed streams. Acidic conditions can alter prey communities and affect amphibian survival, so it was surprising to find populations in more acidic streams, although levels were above those known to harm stream ecosystems. Streams with similar habitat characteristics should be protected to conserve this unique salamander

Forecasting the combined effects of anticipated climate change and agricultural conservation practices on fish recruitment dynamics in Lake Erie

Many aquatic ecosystems are experiencing multiple anthropogenic stressors that threaten their ability to support ecologically and economically important fish species. Two of the most ubiquitous stressors are climate change and non- point source nutrient pollution.Agricultural conservation practices (ACPs, i.e. farming practices that reduce runoff, prevent erosion, and curb excessive nutrient loading) offer a potential means to mitigate the negative effects of non- point source pollution on fish populations. However, our understanding of how ACP implementation amidst a changing climate will affect fish production in large ecosystems that receive substantial upstream sediment and nutrient inputs remains incomplete.Towards this end, we explored how anticipated climate change and the implementation of realistic ACPs might alter the recruitment dynamics of three fish populations (native walleye Sander vitreus and yellow perch Perca flavescens and invasive white perch Morone americana) in the highly productive, dynamic west basin of Lake Erie. We projected future (2020- 2065) recruitment under different combinations of anticipated climate change (n = 2 levels) and ACP implementation (n = 4 levels) in the western Lake Erie catchment using predictive biological models driven by forecasted winter severity, spring warming rate, and Maumee River total phosphorus loads that were generated from linked climate, catchment- hydrology, and agricultural- practice- simulation models.In general, our models projected reduced walleye and yellow perch recruitment whereas invasive white perch recruitment was projected to remain stable or increase relative to the recent past. Our modelling also suggests the potential for trade- offs, as ACP implementation was projected to reduce yellow perch recruitment with anticipated climate change.Overall, our study presents a useful modelling framework to forecast fish recruitment in Lake Erie and elsewhere, as well as offering projections and new avenues of research that could help resource management agencies and policy- makers develop adaptive and resilient management strategies in the face of anticipated climate and land- management change.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156436/2/fwb13515.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156436/1/fwb13515_am.pd

Using citizen science data to identify the sensitivity of species to human land use

Conservation practitioners must contend with an increasing array of threats that affect biodiversity. Citizen scientists can provide timely and expansive information for addressing these threats across large scales, but their data may contain sampling biases. We used randomization procedures to account for possible sampling biases in opportunistically reported citizen science data to identify species' sensitivities to human land use. We analyzed 21,044 records of 143 native reptile and amphibian species reported to the Carolina Herp Atlas from North Carolina and South Carolina between 1 January 1990 and 12 July 2014. Sensitive species significantly associated with natural landscapes were 3.4 times more likely to be legally protected or treated as of conservation concern by state resource agencies than less sensitive species significantly associated with human-dominated landscapes. Many of the species significantly associated with natural landscapes occurred primarily in habitats that had been nearly eradicated or otherwise altered in the Carolinas, including isolated wetlands, longleaf pine savannas, and Appalachian forests. Rare species with few reports were more likely to be associated with natural landscapes and 3.2 times more likely to be legally protected or treated as of conservation concern than species with at least 20 reported occurrences. Our results suggest that opportunistically reported citizen science data can be used to identify sensitive species and that species currently restricted primarily to natural landscapes are likely at greatest risk of decline from future losses of natural habitat. Our approach demonstrates the usefulness of citizen science data in prioritizing conservation and in helping practitioners address species declines and extinctions at large extents

Effects of benthic consumer diversity on stream ecosystem function

Freshwater consumer diversity is being changed at an alarming rate, the causes and ecological consequences of which are often unclear. This is particularly true for amphibian species, which are abundant but often overlooked consumers in many stream ecosystems. The goals of this study were to (1) Examine the impacts of larval salamander diversity on stream ecosystem functioning, (2) Identify potential stressors to salamander diversity, and (3) Examine more generally how changes in consumer functional diversity impact stream ecosystems. In Chapter 1, I used in-stream enclosures to examine the impacts of salamander diversity on macroinvertebrate communities in an Appalachian headwater stream. I found that larval salamanders generally reduced the abundance of macroinvertebrates, but that the more diverse salamander treatment substantially reduced macroinvertebrate abundance compared to control treatments or salamander monocultures. These effects were non-additive and suggest that niche complementarity or facilitation occurred among salamander species. Thus, alterations to salamander diversity may affect macroinvertebrate communities and have cascading effects on stream ecosystems. In Chapter 2, I examined spatial and seasonal heterogeneity in nutrient recycling by larval salamander communities in Appalachian headwater streams. Larval salamander nutrient excretion demonstrated strong spatial and seasonal patterns, contributing c. 17% of the ecosystem demand for NH4+-N prior to leaf fall but only c. 5% after leaf fall. However, in some areas of the stream where salamanders were abundant, they were capable of meeting as much as 50% of the demand for NH4+-N. This suggests that salamanders may create biogeochemical hotspots within streams, but this will vary seasonally. In Chapter 3, I examined how changes in detrital diversity may impact larval salamanders. I found that detrital composition, but not species richness, had a significant effect on salamander abundance. This appeared to be related to differences in prey availability in leaf packs, rather than to structural differences in the habitat provided by different leaf species. Thus, ongoing changes in Appalachian forest diversity may negatively impact salamander populations by disrupting stream food webs. In Chapter 4, I examined a more diverse consumer assemblage in Indiana to examine how changes in consumer functional diversity may impact several ecosystem properties. I found that increasing consumer functional diversity had an overall positive impact on ecosystem productivity, suggesting that ongoing changes in aquatic consumer communities will have a large impact on ecosystem functioning. My results suggest that consumers have a large impact on many stream ecosystem attributes and that changes in consumer diversity may disrupt stream ecosystem functioning. Changes in consumer functional diversity may be particularly important as my results demonstrate that the functional diversity of consumers has a large influence on the impact of consumers on multiple ecosystem attributes. Salamanders appear to be underappreciated consumers in headwater stream ecosystems, and their loss from these ecosystems may alter the supply of biologically important nutrients and the structure of headwater stream food webs. Salamander populations are potentially vulnerable to a multitude of stressors, and I found that changes in leaf litter inputs to streams associated with altered riparian forests might negatively impact salamander populations. More research is needed to understand the population-level effects of altered detrital quality for stream-breeding salamanders