Geology topics

J.B. Mouser

Publications and source records attributed to J.B. Mouser.

6 recordsLinked to original sources

USGS2022

Increased landscape disturbance and streamflow variability threaten fish biodiversity in the Red River catchment, USA

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 occurrence relationships between fish distributions and streamflow and landscape characteristics in the south-central United States. Location Our study area was the central Red River catchment in Oklahoma, Texas and Arkansas, USA. Methods We used existing fish surveys to model the occurrence of a diverse, warmwater assemblage among hydraulic response units (HRUs). We used multispecies occupancy modelling to identify variation in occurrence probability among 111 stream fishes in relation to landscape disturbance and flow regime characteristics. Results We found occurrence relationships with landscape disturbance and 11 metrics comprising all flow-regime components. The relationships varied within both major species groups and some genera. Frequency and duration were the most common metrics underlying flow regime relationships. More common stream fishes tended to be positively associated with higher levels of landscape disturbance and flow regime metrics representing variability; conversely, narrow-ranged fishes tended to be negatively associated. Occurrence relationships with flow metrics representing high-flow events were predominately negative. As expected, many species were strongly associated with ecoregion with landscape disturbance and flow relationships held constant. Main conclusions Our study informs land use and water management decisions and stream fish conservation at multiple spatial scales. Collectively, the findings suggest potential homogenization of the Red River fish assemblage with increased landscape disturbance and streamflow variability. A reduction in landscape disturbance and maintenance of natural flow patterns at coarser scales may benefit endemic and narrow-ranged fishes. Our findings also help guide finer-scale land use and water management decisions by identifying stream network areas with a high occurrence probability of less tolerant fishes.

Arkansas, Oklahoma, Texas↗

USGS2022

Seasonal context of bristly cave crayfish Cambarus setosus habitat use and life history

Cave crayfishes are important members of groundwater communities, but many cave crayfishes are threatened or endangered. Unfortunately, we lack basic life history and ecological data that are needed for developing conservation plans for most cave crayfishes, especially the role of seasonal and annual fluctuations in structuring populations. Therefore, we determined the seasonal life history and habitat use of Cambarus setosus in Smallin Civil War Cave, Christian County, Missouri, United States. We conducted visual crayfish surveys over a 400 m section of the cave from 2006 to 2019. We used multinomial logit, multiple linear regression, and logistic regression models to estimate crayfish substrate, water depth, and water velocity use, respectively. All models included sex, carapace length, season, distance into the cave, and interactions between all variables and sex as predictor terms. We also used t-tests to assess morphometric differences between male and female crayfish. Six mark-recapture events (2010 to 2019) were used to estimate population sizes using a nil-recapture model. We attempted to age eight individuals using gastric mill bands, but annual bands were not discernable. We found reproductively active males during all seasons. We captured one ovigerous female during the spring, though ovigerous females were observed during show cave tours during spring, summer, and autumn. Male C. setosus were more likely to use homogenous and heterogeneous rock substrates and shallower and calmer water when compared to females; however, these relationships varied based on distance into the cave and season. Females sampled were significantly larger than males, and males regenerated chelae more often. Minimum population size estimates ranged from 9 to 159 individuals and indicated the population was relatively stable. Our data provide both a baseline population estimate for comparison with future studies and valuable trait information that is often lacking but useful for developing conservation efforts.

Missouri↗

USGS2021

Refining sampling protocols for cavefishes and cave crayfishes to account for environmental variation

Subterranean habitats support a diverse array of organisms and represent imperative habitats in many conservation strategies; however, subterranean habitats are one of the most difficult environments to study. Accounting for variable sampling detection is necessary to properly evaluate conservation options for rare species such as karst and other groundwater organisms. New sampling methods, such as environmental DNA, show promise to improve stygobiont detection; however, sources of sampling bias are poorly understood. Therefore, our objective was to determine factors affecting detection probability of both visual and environmental DNA (eDNA) surveys for cavefishes and cave crayfishes. We sampled 40 sites across the Ozark Highlands ecoregion in Arkansas, Missouri, and Oklahoma, USA using visual and eDNA surveys. We used occupancy modeling to estimate the detection probability of the two taxa using both survey methods under varying environmental conditions. Overall, eDNA sampling resulted in higher detection probability for cavefishes when compared to visual surveys, whereas visual surveys typically had higher detection probability for cave crayfishes. Greater water volume at the time of sampling was related to lower detection using visual surveys for both taxa, but there was no relationship between eDNA detection and water volume. Detection probability of both cavefishes and crayfishes was higher using visual surveys when sampling units were classified by coarse rather than fine substrate, whereas detection of cave crayfishes surveyed using eDNA was higher in coarse substrate environments. Detection of cavefishes and cave crayfishes was higher via eDNA sampling when water was flowing, but similar sampling conditions resulted in lower detection using visual surveys. Our results indicate detection should be considered when sampling stygobionts even if using traditional visual surveys. Environmental DNA is a useful tool; however, the limitations we identified indicate eDNA for these taxa currently are not adequate to replace traditional surveys in subterranean environments.

Arkansas, Missouri, Oklahoma↗

USGS2020

Preliminary investigation of the critically imperiled Caney Mountain cave crayfish Orconectes stygocaneyi Hobbs III, 2001 (Decapoda: Cambaridae) in Missouri, USA

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 collected (for original species description). We aimed to collect the first natural history data on the species and search adjacent caves and springs for additional populations. Twelve visual searches and supplemental trapping over four years, in all seasons, yielded 69 O. stygocaneyi (including 11 young-of-year) observations and capture of 22 crayfish, including one ovigerous female. Visual searches of nearby caves and springs yielded no O. stygocaneyi records. However, multiple surveys of those caves and springs, using environmental DNA detected the species in one additional cave adjacent to Mud Cave, but only during spring high flow events when the caves may be ephemerally connected. Orconectes stygocaneyi 's distribution is among the most restricted of any North American crayfish, and further evaluation of its conservation status designations might be warranted. Long term conservation of O. stygocaneyi would benefit from management practices promoting sustained, unimpacted surface runoff within Mud Cave's recharge area.

Missouri↗

USGS2018

Subterranean invasion by gapped ringed crayfish: Effectiveness of a removal effort and barrier installation

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 the effects of removal on the population. Crayfish were found throughout the cave though fewer individuals were observed upstream of an installed weir. Fecund females were collected in nearly all months, but were prevalent during spring (February–June). Males and females were of similar sizes. Males had larger chelae and chelae that were regenerated slightly more often than females. Removal of >4000 crayfish since 2011 resulted in reduced abundances, but the population persisted. Age estimates from counting bands on gastric mills indicated crayfish within the cave lived longer than populations in nearby Big Creek (6 vs. 4 years). Recent efforts to prevent upstream cave migrations included a barrier installation and since installation, few crayfish have been located upstream. We show that exploitation of new environments may lead to trait changes (i.e., reproduction and longevity). We also demonstrate that barriers reduce the spread of invasion at a comparable cost to removal. We hypothesize that increased reservoir elevation inundates springs hydrologically connected to the cave and this may be the invasion source.

Missouri↗

USGS2018

Relationships between landscape constraints and a crayfish assemblage with consideration of competitor presence

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-induced changes; and (b) a very limited understanding of how species interactions affect overall crayfish distributions. Location Ozark Highlands ecoregion, USA. Methods We used both existing data and field-collected data to examine the relationships between 12 Faxonius species and physicochemical variables at multiple spatial scales. Data were analysed using a generalized linear mixed model. After fitting our environmental variables, we also considered possible relationships between species considered strong competitors and species occurrence. Results Our results indicated that elevation, lithology, an interaction between drainage area and anthropogenic disturbance, and the presence of strong competitors were associated with Faxonius occurrences. Faxonius occurrences were associated with assemblage-structuring variables: lithology and elevation. More interestingly, we found several patterns of interactions between drainage area and disturbance. The most common pattern among several species was a decline in occurrence in larger drainages when disturbance was high; however, longpincered crayfish ( Faxonius longidigitus ) was more likely to occupy large drainages as disturbance increased. Additionally, the presence of species considered strong competitors resulted in lower occurrence probability for many species, including two of the species classified as competitors. Main conclusions In addition to identifying the relationships between native species and assemblage-structuring variables, we show how the probability of species occurrences relate to interactions between disturbance and natural landscape features. Further, our results suggest competitor presence also plays a role in structuring distributions at the stream segment scale. Our findings emphasize the value of considering both competitor presence and interactions among landscape variables and disturbances in structuring crayfish assemblages.

Arkansas, Missouri↗