Shannon Brewer

Shannon Brewer
Auburn University | AU · School of Fisheries and Allied Aquacultures

About

80
Publications
11,188
Reads
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740
Citations
Introduction
My research is of particular interest to state, federal, and non-governmental agencies because I focus on identifying relations and mechanisms related to rare, declining, or economically important aquatic species for which the causes and corresponding management responses are unclear. As a researcher, I am broadly interested in the conservation and management of lotic ecosystems.
Additional affiliations
April 2020 - present
Alabama Cooperative Fish and Wildlife Research Unit Auburn University
Position
  • Professor
August 2010 - April 2020
Oklahoma State University - Stillwater
Position
  • Assistant Unit Leader

Publications

Publications (80)
Article
Full-text available
Aim Stream fish distributions are hypothesized to be strongly associated with landscape characteristics at multiple scales. Variation in flow regimes and intensity of landscape disturbance are associated with stream fish distributions; however, relationships are poorly understood in many high‐diversity regions. Our objective was to identify occurre...
Article
Stream fish movement in response to changing resource availability and habitat needs is important for fish growth, survival, and reproduction. We used radio telemetry to evaluate individual movements, daily movement rates, home ranges, and habitat‐use characteristics of adult (278–464 mm TL) Neosho Smallmouth Bass Micropterus dolomieu velox in thre...
Article
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Background Movement information can improve conservation of imperiled species, yet movement is not quantified for many organisms in need of conservation. Prairie chub ( Macrhybopsis australis ) is a regionally endemic freshwater fish with unquantified movement ecology and currently considered for listing under the Endangered Species Act. The purpos...
Article
Understanding the thermal tolerances of stream fishes, including sportfishes, is important for assessing thermal stressors common across the landscape. Our study objectives were to determine the thermal tolerances of 17 stream fishes (15 species and two genetically distinct populations of juvenile Smallmouth Bass, the Neosho subspecies Micropterus...
Article
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Stocking of Rainbow Trout Oncorhynchus mykiss commonly provides seasonal or mitigation fisheries; however, these fish are usually small and ecosystem effects are spatially or temporally limited. Yet agencies receive requests to stock Rainbow Trout in relatively natural settings (i.e., not tailwater or mitigation fisheries), where introductions may...
Article
Hydrologic processes are often key determinants of successful recruitment of native fishes. However, water management practices can result in abnormal changes in daily and seasonal hydrology patterns. Rarely has fish recruitment across river‐reservoir landscapes been considered in relation to flow management, despite the direct relationship between...
Article
Reliable fish tagging methods are needed to conduct studies (e.g., movement, habitat, abundance) that inform conservation and management decisions; however, dependable tagging approaches are lacking for many small‐bodied fishes. Therefore, our study objective was to determine survival, tag retention (Visible implant elastomer [VIE], passive integra...
Article
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Subterranean habitats represent focal habitats in many conservation strategies; however, these environments are some of the most difficult to sample. New sampling methods, such as environmental DNA (eDNA), show promise to improve stygobiont detection, but sources of sampling bias are poorly understood. Therefore, we determined the factors affecting...
Article
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Aim Hierarchical stream habitat conditions influence patterns of fish abundance and population dynamics. The spawning period is important for stream fishes but coincides with unpredictable environmental conditions and stressors. Thus, identifying habitats that confer suitable spawning is crucial to managing vulnerable fish populations, including na...
Article
• Dam construction threatens global aquatic biodiversity by fragmenting stream networks and altering flow regimes. The negative effects of dams are exacerbated by increased drought periods and associated water withdrawals, especially in semi-arid regions. Stream fishes are particularly threatened owing to their mobile nature and requirement for mul...
Article
Advantages of passive integrated transponder (PIT) tags are their small size, longevity, and low‐cost compared to other tags. PIT tags are often used in fisheries to study movement patterns, survival, or estimate population size. However, PIT tags are limited by their short detection distance. Mobile PIT antennas may increase the utility of PIT tag...
Article
Stocking Rainbow Trout Oncorhynchus mykiss to create additional angling opportunities is common; however, these fishing opportunities necessitate evaluation in groundwater‐influenced, warmwater streams where the spatial and temporal implications of stocking are unclear. Our objectives were to determine Rainbow Trout dispersal from a stocking locati...
Article
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Due to geologic processes and recent anthropogenic introductions, patterns of genetic and morphological diversity within the Smallmouth Bass (Micropterus dolomieu), which are endemic to the central and eastern United States (USA), are poorly understood. We assessed genetic and morphological differentiation between the widespread Northern Smallmouth...
Article
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Abstract Stream fish survival and recruitment are products of a physicochemical environment that affects growth and provides refuge; yet, the drivers of spatiotemporal variation in juvenile fish abundance remain unclear. Understanding how physicochemical conditions drive spatial and temporal patterns in fish abundances provides insight into how con...
Article
Groundwater influences stream environments in numerous ways including structuring biotic assemblages. However, associations between groundwater influence and warmwater fish assemblages are under-studied. We examined relationships between groundwater contribution, population size, and total length (TL) for 5 warmwater fishes at 32 stream reaches in...
Article
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We used acoustic telemetry and a multistate Cormack‐Jolly‐Seber model to determine seasonal blue sucker Cycleptus elongatus movement from 2015 – 2017. We tested hypotheses using a model ranking approach and determined blue sucker movement patterns in a mainstem reach below a hydropower dam (i.e., tailwater) differed from the movement patterns of bl...
Article
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Counting bands via the gastric mill is a potential direct approach for ageing crayfish; however, the validity of ageing crustaceans using the gastric mill is unknown. Our study objectives were to 1) compare gastric mill age estimates to a traditional aging technique, 2) compare ageing precision among the ossicles, and 3) examine the effects of temp...
Article
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The Caney Mountain cave crayfish (Orconectes stygocaneyi) is one of North America’s rarest crayfish, endemic to one cave in southern Missouri, USA. The species is listed as “critically imperiled” by Missouri, and “threatened” by the American Fisheries Society. Previously, only 15 crayfish have been observed in Mud Cave, and only two have been colle...
Article
Seasonal and life stage variation in microhabitat use is an important driver of fish survival and bioenergetics, but knowledge of microhabitat selection during colder periods is generally lacking in warmwater streams. Our objective was to examine changes in microhabitat selection by age‐0 (TL ≤ 85 mm) and age‐1+ (TL > 85 mm) Smallmouth Bass Micropt...
Article
Restoring groundwater flow is a management option that improves water temperature regimes and benefits fishes. Although this strategy applies more readily to river systems, the thermal character of reservoirs is heavily influenced by inflowing rivers. We examined differences in age, structure, and growth of both Freshwater Drum Aplodinotus grunnien...
Article
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The development of a hydrologic foundation, essential for advancing our understanding of flow‐ecology relationships, was developed using the high‐resolution physics‐based distributed rainfall‐runoff model Vflo in a semi‐arid region. We compared the accuracy and bias associated with flow metrics that were generated using Vflo, gauge data, and draina...
Chapter
Unique genetic lineages of Micropterus species are increasingly recognized; however, little effort has been devoted to identifying their ecological relationships despite recognition of their conservation value by management agencies. Our study objectives were to determine young-of-year, first-summer survival, and examine overall channel-unit habita...
Article
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Non-native crayfish invasion is a major threat to many stream fauna; however, invasions in subterranean habitats are rarely documented. Our study objectives were to examine demographics and morphological and life-history traits of a gapped ringed crayfish Faxonius neglectus chaenodactylus population that invaded Tumbling Creek Cave and determine th...
Article
Aim Crayfish are globally diverse and one of the most important taxa in North American streams. Despite their importance, many species are of conservation concern and efforts to improve conditions are limited. Here, we address two major impediments to improving conditions: (a) our lack of knowledge of the interplay among natural landscape and human...
Article
The Neosho Smallmouth Bass (Micropterus dolomieu velox) is endemic to Arkansas River tributaries originating in the Ozark Highlands and Boston Mountains. Although morphologically and genetically distinct from other Smallmouth Bass (SMB) populations, conservation‐genetic status of Neosho SMB is largely unknown. To assist in filling this data gap, we...
Article
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The continued evaluation of fish-sampling gears and methods is essential to identify their applicability across environmental conditions and among species. Although limited by visibility, snorkeling has potential advantages relative to other fish-sampling gears in wadeable streams (e.g., minimally intrusive, cost effective, and appropriate in deepe...
Article
Ecohydrology combines empiricism, data analytics, and the integration of models to characterize linkages between ecological and hydrological processes. A challenge for practitioners is determining which models best generalizes heterogeneity in hydrological behavior, including water fluxes across spatial and temporal scales, integrating environmenta...
Article
Many crayfish are of conservation concern because of their use of unique habitats and often narrow ranges. In this study, we determined fine-scale habitat use by 3 crayfishes that are endemic to the Ouachita Mountains, in Oklahoma and Arkansas. We sampled Faxonius menae (Mena Crayfish), F. leptogonopodus (Little River Creek Crayfish), and Fallicamb...
Article
Stream and groundwater interactions play an essential role in regulating flow, temperature, and water quality for stream ecosystems. Temperature gradients have been used to quantify vertical water movement in the streambed since the 1960s, but advancements in thermal methods are still possible. Seepage runs are a method commonly used to quantify ex...
Article
Species detection error (i.e., imperfect and variable detection probability) is an essential consideration when investigators map distributions and interpret habitat associations. When fish detection error that is due to highly variable instream environments needs to be addressed, sand-bed streams of the Great Plains represent a unique challenge. W...
Article
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Altered flow regimes in streams can significantly affect ecosystems and disturb ecological processes, leading to species loss and extinction. Many river management projects use stream classification and habitat assessment approaches to design practical solutions to reverse or mitigate adverse effects of flow regime alteration on stream systems. The...
Article
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Temporal and spatial variability in streams result in heterogeneous gear capture probability (i.e., the proportion of available individuals identified) that confounds interpretation of data used to monitor fish abundance. We modeled tow-barge electrofishing capture probability at multiple spatial scales for nine Ozark Highland stream fishes. In add...
Article
Anthropogenic changes to the Great Plains rivers of North America have had a large, negative effect on a reproductive guild of pelagic-broadcast spawning (PBS) cyprinid fishes. The group is phylogenetically diverse, with multiple origins of the PBS mode. However, because of incomplete life-history information, PBS designation often relies only on h...
Article
A thermal tolerance study mimicking different stream environments could improve our ecological understanding of how increasing water temperatures affect stream ectotherms and improve our ability to predict organism responses based on river classification schemes. Our objective was to compare the thermal tolerances of stream fishes of different habi...
Article
Full-text available
Although numerous studies have assessed retention and survival of passive integrated transponder (PIT) tags, data are scattered and information gaps remain for many diminutive fishes. Our study objectives were to 1) systematically review PIT tag studies and summarize retention, growth, and survival data for warmwater fishes; and 2) conduct a labora...
Article
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Decreases in the abundance and diversity of stream fishes in the North American Great Plains have been attributed to habitat fragmentation, altered hydrological and temperature regimes, and elevated levels of total dissolved solids and total suspended solids. Pelagic-broadcast spawning cyprinids, such as the Arkansas River Shiner Notropis girardi,...
Article
Failure to account for variable detection across survey conditions constrains progressive stream ecology and can lead to erroneous stream fish management and conservation decisions. In addition to variable detection’s confounding long-term stream fish population trends, reliable abundance estimates across a wide range of survey conditions are funda...
Article
2017 John Wiley & Sons Ltd. Anthropogenic changes to the Great Plains rivers of North America have had a large, negative effect on a reproductive guild of pelagic-broadcast spawning (PBS) cyprinid fishes. The group is phylogenetically diverse, with multiple origins of the PBS mode. However, because of incomplete life-history information, PBS design...
Article
Truncated distributions of pelagophilic fishes have been observed across the Great Plains of North America, with water use and landscape fragmentation implicated as contributing factors. Developing conservation strategies for these species is hindered by the existence of multiple competing flow regime hypotheses related to species persistence. Our...
Article
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The global recognition of the importance of natural flow regimes to sustain the ecological integrity of river systems has led to increased societal pressure on the hydropower industry to change plant operations to improve downstream aquatic ecosystems. However, a complete reinstatement of natural flow regimes is often unrealistic when balancing wat...
Article
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Environmental flows represent a legal mechanism to balance existing and future water uses and sustain non-use values. Here, we identify current challenges, provide examples where they are important, and suggest research advances that would benefit environmental flow science. Specifically, environmental flow science would benefit by (1) developing a...
Technical Report
Full-text available
Stocking black basses (Micropterus spp.) is a common practice used to increase angling opportunities in impoundments; however, when non-native black basses are introduced they often invade riverine habitats where they threaten the persistence of other fishes, including native black basses. Neosho Smallmouth Bass (M. dolomieu velox) is endemic to po...
Article
Identifying ontogenetic shifts in habitat use by aquatic organisms is necessary for improving conservation strategies; however, our ability to designate life stages based on surrogate metrics (i.e., length) is questionable without validation. This study identified growth patterns of age-0 western painted crayfish Orconectes palmeri longimanus (Faxo...
Article
The change of flow regime under the disturbance of human activity leads to alteration in fish distribution. To accurately analyze key eco-hydrological characteristics, Arkansas River federally endangered small-bodied fish: pelagic broadcast-spawning cyprinids reproductive guild (Arkansas River Shiner, Notropis girardi, "ARS" for short) was studied....
Chapter
We reviewed the published and gray literature associated with Neosho Smallmouth Bass Micropterus dolomieu velox and the genetically distinct Ouachita lineage. Substantial interstream variation appears to occur among these populations, particularly related to age. The Neosho subspecies is more abundant, grows faster, and lives longer than the geneti...
Article
Crayfish in many headwater streams regularly cope with seasonal drought. However, it is unclear how landscape changes affect the long-term persistence of crayfish populations. We designed two laboratory experiments to investigate the acute effects of common landscape stressors on crayfish: water withdrawal and sedimentation. The first experiment te...
Article
Side-scan sonar is a valuable tool for mapping habitat features in many aquatic systems suggesting it may also be useful for locating sedentary biota. The objective of this study was to determine if side-scan sonar could be used to identify freshwater mussel (unionid) beds and the required environmental conditions. We used side-scan sonar to develo...
Conference Paper
Anthropogenic changes to riverine systems are pervasive and multifaceted with flow modifications often a driver of changing inchannel conditions. Climate and land-use change contribute to inchannel alterations by changing runoff patterns and constituents delivered to stream ecosystems. These threats combined create a difficult situation for managin...
Conference Paper
River fragmentation and associated flow alteration and habitat degradation are significant factors in the decline and extinction of freshwater biota. One group of imperilled fishes, pelagic-broadcast spawning cyprinids release semi-buoyant eggs that require sufficient velocities and river-fragment length during early development. However, it is unk...
Conference Paper
Full-text available
The continuing degradation of fish populations and associated habitat in streams and rivers, despite the efforts of competent and dedicated individuals, suggests that a different approach might be helpful to training our future leaders. The objective of our talk is to suggest a new goal for success in the fisheries profession and describe the role...
Article
Full-text available
Habitat fragmentation and flow regulation are significant factors related to the decline and extinction of freshwater biota. Pelagic-broadcast spawning cyprinids require moving water and some length of unfragmented stream to complete their life cycle. However, it is unknown how discharge and habitat features interact at multiple spatial scales to a...
Article
Crayfish (saddlebacked crayfish, Orconectes medius) catch was compared using a kick seine applied two different ways with a 1-m(2) quadrat sampler (with known efficiency and bias in riffles) from three small streams in the Missouri Ozarks. Triplicate samples (one of each technique) were taken from two creeks and one headwater stream (n = 69 sites)...
Article
The Moore egg collector (MEC) was developed for quantitative and nondestructive capture of semibuoyant fish eggs. Previous studies have indicated that capture efficiency of the MEC was low and the use of one device did not adequately represent the spatial distribution within the water column of egg surrogates (gellan beads) of pelagic broadcast-spa...
Article
Full-text available
Pelagic broadcast spawning cyprinids are common to Great Plains rivers and streams. This reproductive guild produces non-adhesive semi-buoyant eggs that require sufficient current velocity to remain in suspension during development. Although studies have shown that there may be a minimum velocity needed to keep the eggs in suspension, this velocity...
Conference Paper
Climate change is expected to cause prolonged droughts and more severe spates. The Ouachita Mountains already experience seasonal droughts from May to October. Endemic crayfish have evolved to survive local conditions; however, the mechanisms used to survive extreme conditions and the timing are largely unknown. Understanding drought responses will...
Conference Paper
Only ecological-relevant instream flows will adequately protect lotic biota from the extreme consequence of flow alterations. By linking flows to key biological processes, managers can identify actual environmental thresholds for target species. Connectivity is a good example where loss of functional connectivity occurs at a discharge above where s...
Conference Paper
Tenkiller Ferry is a 5,220 ha reservoir on the Illinois River in eastern Oklahoma that was impounded for flood control and hydroelectric power. Rainbow trout were established as the primary mitigation for the loss of the warm-water fishery in the lower Illinois River. No instream flow standards or water storage have been allocated to support the tr...
Article
Conservation efforts for threatened or endangered species are challenging because the multi-scale factors that relate to their decline or inhibit their recovery are often unknown. To further exacerbate matters, the perceptions associated with the mechanisms of species decline are often viewed myopically rather than across the entire species range....
Article
1. A major limitation to effective management of narrow-range crayfish populations is the paucity of information on the spatial distribution of crayfish species and a general understanding of the interacting environmental variables that drive current and future potential distributional patterns. 2. Maximum Entropy Species Distribution Modeling Soft...
Article
I examined how land use influenced the distribution of Smallmouth Bass Micropterus dolomieu in channel units (discrete morphological features—e.g., pools) of streams in the Midwestern USA. Stream segments (n = 36), from four clusters of different soil and runoff conditions, were identified that had the highest percent of forest (n = 12), pasture (n...
Article
This study examined how spring-flow (SF) contributions to streams related to the distribution and abundance of smallmouth bass Micropterus dolomieu in a predominately pasture landscape in Missouri, USA. Stream segments (N = 13) with similar landscape characters were classified by SF volume into high SF (HSF) or low SF (LSF) groups. The densities of...
Article
Quantitative studies focusing on the collection of semibuoyant fish eggs, which are associated with a pelagic broadcast-spawning reproductive strategy, are often conducted to evaluate reproductive success. Many of the fishes in this reproductive guild have suffered significant reductions in range and abundance. However, the efficiency of the sampli...
Conference Paper
Quantitative studies focusing on the collection of semi-buoyant fish eggs, associated with a pelagic broadcast-spawning reproductive strategy, are often conducted to evaluate reproductive success. Many fishes represented in this reproductive guild are considered threatened or endangered. However the efficiency of the sampling gear used to evaluate...
Conference Paper
Arkansas River shiner (ARS) Notropis girardi, a federally threatened species is a small cyprinid native to rivers in the Great Plains ecoregion. It is a member of a reproductive guild of pelagic-spawning cyprinids inhabiting the rivers of the Great Plains. This species releases non-adhesive, semi-buoyant eggs during an extended spawning season. The...
Article
Abstract Young‐of‐the‐year (YOY) smallmouth bass, Micropterus dolomieu Lacepéde, were evaluated in streams from eight catchments with two contrasting land uses to determine their use of microhabitats under a variety of stream conditions. Step‐wise discriminant function analyses revealed patterns of habitat use by discriminating used from available...
Article
Full-text available
This study examined how interactions between natural landscape features and land use influenced the abundance of smallmouth bass, Micropterus dolomieu, in Missouri, USA, streams. Stream segments were placed into one of four groups based on natural-occurring watershed characteristics (soil texture and soil permeability) predicted to relate to smallm...
Article
Accurate determination of the distribution and abundance of age-0 sport fish, such as smallmouth bass Micropterus dolomieu, is an important aspect of successful species management (e.g., characterizing nursery habitats for protection or enhancement; identifying reproductive dynamics and influences of environmental variables). Two observational tech...
Article
We determined densities of orangethroat darter (Etheostoma spectabile) from different channel units during winter, the relation between fish size and channel unit used, and the microhabitat conditions related to the densities of this species. A quadrat sampler and backpack electrofishing were combined to sample darters from different channel units...
Article
Full-text available
We examined the hypothesis that secondary production of a community of stream crayfish (Orconectes spp.) depended upon the available suite of channel units (e.g., riffle, run, pool) and that age-specific use of channel units was the important underlying mechanism. Nine cohorts of each of three species over a 10-year period at two sites on the Jacks...
Article
Currently, no flow regulations exist for the protection of riverine fishes in Missouri. Prerequisites for establishing flow guidelines are understanding what habitats are used by fishes at different times of the year and how much of that habitat will be available to each species under different discharge scenarios. We quantified microhabitat associ...
Article
Full-text available
Brewer SK, Rabeni CF, Papoulias DM. Comparing histology and gonadosomatic index for determining spawning condition of small-bodied riverine fishes.Ecology of Freshwater Fish 2008: 17: 54–58. © 2007 The Authors. Journal compilation © 2007 Blackwell Munksgaard Abstract – We compared gonadosomatic index (GSI) and histological analysis of ovaries for i...
Article
Full-text available
Protecting and restoring fish populations on a regional basis are most effective if the multiscale factors responsible for the relative quality of a fishery are known. We spatially linked Missouri's statewide historical fish collections to environmental features in a geographic information system, which was used as a basis for modeling the importan...