Faxonius wrighti, Hardin Crayfish, is an imperilled crayfish patchily distributed throughout five small tributaries entering the Tennessee River in southwestern Tennessee and northeastern Mississippi. Past field observations suggest that channelization and sedimentation contributed to its patchy distribution; however, this assumption has not been explicitly tested. We conducted 219 mesohabitat surveys across 22 stream reaches within the range of F. wrighti to characterize species-habitat patterns of F. wrighti presence at segment-, reach- and mesohabitat-scales. Raw detection was low across mesohabitat surveys, with F. wrighti only being detected at 30 of 219 mesohabitats (raw detection = 14%). Despite low detection, F. wrighti was observed in 10 reaches (na & iuml;ve occurrence = 45%), with the highest rate in the Beason Creek tributary system with four occupied reaches. Several historic localities in three tributary systems yielded no detections, but a new locality was documented within Shiloh National Battlefield Park. At the segment scale, F. wrighti presence was positively associated with stream slope and soils that allow infiltration and reduce sediment delivery from runoff, and negatively associated with increased landscape disturbance. At the reach scale, presence was negatively associated with both silt depth and proportion of the reach covered by silt. At the mesohabitat scale, water depth, silt depth, and the presence of another stream-dwelling crayfish, F. etnieri, were top predictors associated with F. wrighti presence. These findings support a link between F. wrighti presence and sediment-related variables across spatial scales, confirming past anecdotal survey observations. Conservation actions aimed at reducing sedimentation and restoring channel complexity are likely to enhance the long-term viability of F. wrighti and facilitate recolonization of historically occupied reaches.

Etheostoma striatulum (Striated Darter) is an increasingly rare darter found in the middle-to- upper regions of the Duck River watershed in Tennessee. This rarity, coupled with a lack of collection and sampling, has put them in review for listing under the Endangered Species Act. Because of the Striated Darters' reclusive and cryptic behavior, conventional techniques tend to be less effective for detection, requiring more precise and sensitive methods. To provide information regarding distribution and occupancy within the Duck River, we used molecular detection of species- specific environmental DNA to test for presence of the species at historical sampling sites. Assessments indicate that Striated Darter is persisting in all tributaries of historical occurrence, with the addition of 4 new tributaries. However, given that 16 sites produced positive signals for less than a third of qPCR replicates, it appears that 60% of these populations are persisting at low detection levels. Detection was positively correlated with turbidity, which could be explained by their preference for lower-velocity habitats. Our results will assist with identifying criticalhabitat locations for the update on the status of Striated Darter while also aiding in the standardization of eDNA- assay development for rare and cryptic species.

Spawning migrations of fishes are common case studies for examining the magnitude of resource subsidies; however, no studies have evaluated this phenomenon in iteroparous migrations of the Catostomid (i.e. suckers) genus Moxostoma (i.e. redhorses). Fish resource subsidies are usually represented as nitrogen (N) and phosphorus (P), and migratory redhorses can deliver these nutrients via excretion and eggs. We evaluated whether redhorses deliver N and P subsidies to Brasstown Creek-a fourth-order stream in the Southeastern US-during their spawning migrations. We measured individual-level nutrient contributions from excretion and eggs and extrapolated those values to estimate nutrient contributions based on daily abundances of migratory redhorses. We compared daily nutrient inputs to daily nutrient exports to determine the potential for resource subsidies. We estimated 71.6 kg of N and 4.4 kg of P were delivered to Brasstown Creek over a 98-day migration period. N input exceeded N export on 15 of the 98 days, but phosphorus input never exceeded P export. Eggs accounted for the majority of N and P input at 51% and 100% respectively. Redhorse N inputs peaked in the spring during a period of low N exports, suggesting that redhorse subsidies were delivered during times of elevated nutrient demand and relatively low nutrient availability. Suckers receive little management attention, and several species of redhorses are imperilled. Given our conclusion that redhorses provide a temporally critical N subsidy that is likely available to multiple consumers in freshwater food webs, this study provides compelling motivation for increased conservation of these species and their migrations.

The ability for migratory fishes to move commonly limiting resources such as nitrogen (N) and phosphorus (P) between discrete environments can have pronounced effects on recipient ecosystems. To further understand the geographic and taxonomic scope of migratory fish resource subsidies, we quantified N and P subsidies delivered by adfluvial suckers (Smallmouth Buffalo, Ictiobus bubalus) via excretion, eggs and carcasses to a small oligotrophic stream during their annual spawning migration. We also compared nutrient inputs from migrant buffalo with watershed nutrient export to assess the likelihood that delivered nutrients were ecologically important. We estimated that approximately 67,000 buffalo delivered 730 kg of N and 80 kg of P to Citico Creek as a result of excretion and egg subsidies across three migration waves. We estimated that carcasses delivered negligible amounts of N and P due to extremely low retention. The ratio of migrant inputs (M-w) to system export (E-w; M-w/E-w) varied amongst three migration waves and compounds (i.e. dissolved inorganic nitrogen, ammonium and soluble reactive phosphorus), with values for M-w/E-w ranging from 0.25 to 5.10, reflecting the potential of nutrient subsidies to exceed nutrients exported from the system under certain conditions. Our findings suggest that suckers have the potential to deliver large resource subsidies to their spawning habitats and that these subsidies may be ecologically important, thus warranting additional consideration of the functional relevance of nongame fishes and their migrations.

Physaria globosa (Brassicaceae), commonly known as Short's Bladderpod, is a federally protected species restricted to Tennessee, Kentucky, and southern Indiana. In 2016, we studied aspects of life history and ecology in a population of P. globosa near Hartsville, Tennessee. Our objectives were to document fecundity-related life history traits and to examine the potential influence of light levels and soil depth on plant growth and reproductive output. In addition, we examined 45 herbarium specimens of P. globosa to assess the potential relationship between taproot size and number of inflorescences per plant. We found the strongest positive relationships between the number of flowering stems per plant and the number of flowers and fruits per plant. Relationships between light levels, soil depth, and biotic factors were only weakly significant. Taproot width was positively correlated with the number of flowering stems on herbarium specimens. Our findings increase the life history and ecology knowledge base available to guide ongoing recovery efforts for the species.

Many species have distributions that span distinctly different physiographic regions, and effective conservation of such taxa will require a full accounting of all factors that potentially influence populations. Ecologists recognize effects of physiographic differences in topography, geology and climate on local habitat configurations, and thus the relevance of landscape heterogeneity to species distributions and abundances. However, research is lacking that examines how physiography affects the processes underlying metapopulation dynamics. We used data describing occupancy dynamics of stream fishes to evaluate evidence that physiography influences rates at which individual taxa persist in or colonize stream reaches under different flow conditions. Using periodic survey data from a stream fish assemblage in a large river basin that encompasses multiple physiographic regions, we fit multi-species dynamic occupancy models. Our modeling results suggested that stream fish colonization but not persistence was strongly governed by physiography, with estimated colonization rates considerably higher in Coastal Plain streams than in Piedmont and Blue Ridge systems. Like colonization, persistence was positively related to an index of stream flow magnitude, but the relationship between flow and persistence did not depend on physiography. Understanding the relative importance of colonization and persistence, and how one or both processes may change across the landscape, is critical information for the conservation of broadly distributed taxa, and conservation strategies explicitly accounting for spatial variation in these processes are likely to be more successful for such taxa.

In recognition of the influence of flow on riverine habitats and organisms, stream ecologists have devoted considerable effort to the development of quantitative predictive relationships describing ecological responses to flow variability, i.e. flow-ecology relationships. Methods used to generate flow-ecology relationships can be thought of as a continuum bookended by pure states approaches on one end and by rates approaches on the other. In pure states approaches, the ecological response is a snapshot of a condition or property (i.e. a state) derived from a single measurement in time. In contrast, ecological responses in rates approaches reflect temporal change (i.e. a rate) and are thus reliant on repeated measurements made over time. Here, we elaborate on the fundamental characteristics of different approaches (pure states, rates and an intermediate approach we call repeated states) for generating flow-ecology relationships, examine how commonly the different approaches are used in the flow-ecology literature, conduct an independent analysis to illustrate the different outcomes achieved by applying repeated-states and rates approaches using a dataset for stream fish diversity in relation to flow magnitude, and identify some of the different ways ecologists are applying rates approaches in flow ecology. Our literature review revealed that repeated-states approaches (53% of reviewed studies) were used far more commonly than either pure states (19%) or rates (12%) approaches to generate flow-ecology relationships. The remaining hybrid studies (17%) used both state and rate responses, and thus also relied on repeated measurements over time. Despite frequent collection of data suitable for rates approaches, flow-ecology relationships have generally been developed using states approaches that relate changes in ecological states to different long-term average flow conditions, rather than to specific flow sequences over much shorter time intervals. Such flow-ecology relationships cannot generate temporally specific predictions of ecological responses to changing flow conditions (i.e. the expected change in state following a specific flow sequence), nor can they describe demographic processes underlying observed changes. While there are different scenarios in which a pure or repeated-states approach would be useful, more frequent use of rates approaches would increase our ability to test flow-ecology hypotheses and our mechanistic understanding of flow-ecology relationships.

Migratory fishes can affect tributary ecosystem properties given their potential to introduce nutrients (fertilize) and physically modify habitat (engineer) during spawning. Nonetheless, migrant effects are frequently context-dependent, and it is useful to understand their strength relative to other potential ecosystem drivers. We examined whether tributary ecosystem properties varied in response to migrations of two adfluvial salmonids, taking advantage of differences in migration timing and reproductive strategy between species, as well as hydrogeomorphic differences between a pair of tributaries. For analyses, we used a model comparison approach to evaluate migrant effects relative to other possible drivers. We observed that Bonneville cutthroat trout (Oncorhynchus clarkii utah) engineered benthic chlorophyll a in redds, with reduction (51% ± 16% decrease) generally occurring during migrations. Contrary to expectations, migrant fertilization effects were not pronounced even in the more retentive tributary during migration by species (kokanee, Oncorhynchus nerka) that exhibited high postspawning mortality. Based on multimodel comparisons, isolated migrant effects were not the primary influence on measured ecosystem properties. Our findings underscore the need to consider different biotic and abiotic conditions that can mediate migratory fish effects.

Free-flowing river segments provide refuges for many imperiled aquatic biota that have been extirpated elsewhere in their native ranges. These biodiversity refuges are also foci of conservation concerns because species persisting within isolated habitat fragments may be particularly vulnerable to local environmental change. We have analyzed long-term (14- and 20-y) survey data to assess evidence of fish species declines in two southeastern U.S. rivers where managers and stakeholders have identified potentially detrimental impacts of current and future land uses. The Conasauga River (Georgia and Tennessee) and the Etowah River (Georgia) form free-flowing headwaters of the extensively dammed Coosa River system. These rivers are valued in part because they harbor multiple species of conservation concern, including three federally endangered and two federally threatened fishes. We used data sets comprising annual surveys for fish species at multiple, fixed sites located at river shoals to analyze occupancy dynamics and temporal changes in species richness. Our analyses incorporated repeated site-specific surveys in some years to estimate and account for incomplete species detection, and test for species-specific (rarity, mainstem-restriction) and year-specific (elevated frequencies of low- or high-flow days) covariates on occupancy dynamics. In the Conasauga River, analysis of 26 species at 13 sites showed evidence of temporal declines in colonization rates for nearly all taxa, accompanied by declining species richness. Four taxa (including one federally endangered species) had reduced occupancy across the Conasauga study sites, with three of these taxa apparently absent for at least the last 5 y of the study. In contrast, a similar fauna of 28 taxa at 10 sites in the Etowah River showed no trends in species persistence, colonization, or occupancy. None of the tested covariates showed strong effects on persistence or colonization rates in either river. Previous studies and observations identified contaminants, nutrient loading, or changes in benthic habitat as possible causes for fish species declines in the Conasauga River. Our analysis provides baseline information that could be used to assess effectiveness of future management actions in the Conasauga or Etowah rivers, and illustrates the use of dynamic occupancy models to evaluate evidence of faunal decline from time-series data.

Thursday 16 November 2017 7:15 to 8:00 – Registration 8:00 – Welcome 8:15 to 9:45 – 1 st session morning talks 9:45 to 10:15 – Morning break 10:15 to 12:00 – 2 nd session morning talks 12:00 to 1:30 – Lunch 1:30 to 2:45 – 1 st session afternoon talks 2:45 to 3:15 – Afternoon break 3:15 to 4:30 – 2 nd session afternoon talks 4:30 to 6:00 – SFC Business Meeting 6:30 to 6:45 – Poster setup 7:00 to 10:00 – Poster session Tennessee Aquarium 10:30 to 12:00 – Auction at hotel

Biased perspectives of fisheries researchers may hinder scientific progress and effective management if limiting factors controlling productivity go unrecognized. We investigated whether river and lake researchers used different approaches when studying salmonid production and whether any differences were ecologically supported. We assessed 564 peer-reviewed papers published between 1966 and 2012 that studied salmonid production or surrogate variables (e. g., abundance, growth, biomass, population) and classified them into five major predictor variable categories: physical habitat, fertility (i. e., nutrients, bottom-up), biotic, temperature, and pollution. The review demonstrated that river researchers primarily analyzed physical habitat (65% of studies) and lake researchers primarily analyzed fertility (45%) and biotic (51%) variables. Nevertheless, understudied variables were often statistically significant predictors of production for lake and river systems and, combined with other evidence, suggests that unjustified a priori assumptions may dictate the choice of independent variables studied. Broader consideration of potential limiting factors on fish production, greater research effort on understudied genera, and increased publication in broadly scoped journals would likely promote integration between lentic and lotic perspectives and improve fisheries management.

Summary Consumer excretion can be an important component of nutrient cycling in aquatic ecosystems. Uncertainty concerning the functional role of many freshwater organisms remains, including those with migratory life‐history strategies that may introduce nutrients to recipient systems. We quantified the magnitude, variability and importance of excretion by migratory fish in the context of stream nutrient cycling. In 2011–12, we collected data from tributaries of a central Utah reservoir used by two potamodromous fishes (Bonneville cut‐throat trout – BCT, Oncorhynchus clarkii utah; kokanee salmon – KOK, Oncorhynchus nerka) with temporally separated spawning migrations. To quantify the contribution of the two migratory freshwater fishes to nutrient cycling, we extrapolated measurements of per capita nitrogen (N) and phosphorus (P) excretion rates to the population level within the local environmental context of two tributaries. We observed differences in excretion subsidies between species and tributaries. BCT excretion rates and ratios were significantly greater than those for KOK. Estimates of the ratio of population‐level migrant excretion to tributary nutrient export were highly variable through time and between tributaries. These estimates were influenced by spatiotemporal hydrologic variation and positively related to ratios of migrant biomass to discharge. During migrations, daily migrant excretion loading comprised a maximum of 6–859% and 1–388% of tributary NH4‐N and soluble reactive phosphorus (SRP) export, respectively. Measurements of nutrient uptake suggested that migrant excretion could meet a substantial portion of ecosystem nutrient demand. Migrant excretion fluxes comprised 46–188% of ecosystem NH4‐N demand and varied between streams and species. In contrast, the proportion of SRP demand supplied by migrant excretion (34–37%) was relatively invariant. These results demonstrate an important role for potamodromous fishes as nutrient sources in recipient ecosystems. Furthermore, our data support predictions about when and where effects of fish‐derived nutrients will be strongest, thereby advancing the understanding of context‐dependent migratory fish effects in riverine ecosystems. Although widespread and common, potamodromous fishes are overlooked but important organisms capable of substantially affecting stream nutrient cycling.

The sport of golf has grown tremendously in the past three decades. It is now the leading sport in the world in terms of total economic expenditure, yet surprising little on golf has appeared in the academic sports studies literature. In particular, the impact of golf on the environment has been virtually absent from discussion. Golf takes place in the outdoors, yet golf course development and maintenance has involved many aspects that are deleterious to the environment. This article charts the impact of golf on the environment from an international perspective, particularly noting emerging differences in first and developing world countries.

Relationships between water chemistry, microbial activity, and hydrology were examined in Chickasawhatchee Creek, a small coastal plain stream in southwestern Georgia. Microbial activity in the creek was determined by measurement of water-column respiration rates and growth-limiting substrates through oxygen consumption experiments. Water chemistry parameters (nitrate-N, soluble reactive phosphate, dissolved organic and inorganic carbon, major cation species) were measured in order to evaluate introduction and removal of various compounds and to identify ground water contributions. Results indicated substantial differences in water chemistry between the upstream and downstream reaches that were related to streamflow variation. During low flow periods, the upper reach of the creek was regulated by surface runoff while groundwater inflow played a more important role in the lower reach. Conversely, during periods of high flow, surface water runoff dictated streamflow for the entire system. There is strong evidence that dissolved organic carbon (DOC) always served as the growth-limiting substrate, and that DOC concentrations varied based on dilution by low-DOC groundwater. However, there was no correlation between measurements of water-column respiration and dissolved organic carbon.

Relationships between water chemistry, microbial activity, and hydrology were examined in Chickasawhatchee Creek, a small coastal plain stream in southwestern Georgia. Microbial activity in the creek was determined by measurement of water-column respiration rates and growth-limiting substrates through oxygen consumption experiments. Water chemistry parameters (nitrate-N, soluble reactive phosphate, dissolved organic and inorganic carbon, major cation species) were measured in order to evaluate introduction and removal of various compounds and to identify ground water contributions. Results indicated substantial differences in water chemistry between the upstream and downstream reaches that were related to streamflow variation. During low flow periods, the upper reach of the creek was regulated by surface runoff while groundwater inflow played a more important role in the lower reach. Conversely, during periods of high flow, surface water runoff dictated streamflow for the entire system. There is strong evidence that dissolved organic carbon (DOC) always served as the growth-limiting substrate, and that DOC concentrations varied based on dilution by low-DOC groundwater. However, there was no correlation between measurements of water-column respiration and dissolved organic carbon.

The lower Flint River in southwestern Georgia flows through the limestone formation of the Upper Floridan aquifer, and large exchanges of water occur through natural spring conduits between the river and the aquifer. Our studies center on how exchanges of river and aquifer water affect these aquatic ecosystems, particularly during periods of drought when both the aquifer and river are heavily stressed due to the combined effects of climatic conditions and human use. Large increases in nitrate and calcium concentrations in the lower Flint River between Albany and Bainbridge are attributed to an increase in the proportion of aquifer water that comes in from springs. Conversely, decreases in phosphate and ammonium result from dilution by groundwater. Measurements of microbial metabolism based on oxygen consumption indicate very low rates of bacterial activity and a strong dependency on bioavailable dissolved organic carbon during drought conditions. Groundwater inputs from the Upper Floridan aquifer play a critical role in maintaining the health of the river and should be sustained to ensure the ecological integrity of the lower Flint River ecosystem.

The lower Flint River in southwestern Georgia flows through the limestone formation of the Upper Floridan aquifer, and large exchanges of water occur through natural spring conduits between the river and the aquifer. Our studies center on how exchanges of river and aquifer water affect these aquatic ecosystems, particularly during periods of drought when both the aquifer and river are heavily stressed due to the combined effects of climatic conditions and human use. Large increases in nitrate and calcium concentrations in the lower Flint River between Albany and Bainbridge are attributed to an increase in the proportion of aquifer water that comes in from springs. Conversely, decreases in phosphate and ammonium result from dilution by groundwater. Measurements of microbial metabolism based on oxygen consumption indicate very low rates of bacterial activity and a strong dependency on bioavailable dissolved organic carbon during drought conditions. Groundwater inputs from the Upper Floridan aquifer play a critical role in maintaining the health of the river and should be sustained to ensure the ecological integrity of the lower Flint River ecosystem.