Canal National Historical Park Research Articles

Before, during, and irrespective of the pandemic: leisure constraints and urban national park visitation

ABSTRACT Urban and urban-proximate national park sites provide diverse leisure opportunities for residents, yet potential barriers and constraints for visitation exist. We examined constraints prior to, during, and regardless of the COVID-19 pandemic in the Washington, D.C. Metro area at Rock Creek Park and Chesapeake and Ohio Canal National Historical Park. Visitors and non-visitors (n = 840) responses were assessed for differences in their (1) demographic characteristics and leisure activities, (2) perceived constraints, and (3) the (a)temporal dimensions of these constraints (i.e. considering or despite COVID-19). Findings illustrate constraints were largely similar for both populations, but non-visitors reported significantly more physical limitations during the pandemic; overall, this demographically diverse group reported significantly less knowledge related to national park site visitation. Findings help point park managers towards information, outreach, and social support as potential tools to improve the visitor experience in these and other national park unit settings.

Evidence for metapopulation structure in seep-dwelling amphipods

Twelve seepage springs in a 3 km2 area of the Goldmine Tract in the C&O Canal National Historical Park in Montgomery County, Maryland, USA were sampled in 1994–1995 and again in 2023 for three amphipod species: Stygobromus tenuis potomacus, Stygobromus pizzinii, and Crangonyx shoemakeri. During that time interval, there were 11 colonizations and 1 exinction. Three populations persisted. These results are consistent with the proposed metapopulation hypothesis of population structure.

Spatial Capture–Recapture Derived Turtle Capture Probabilities and Densities in the Chesapeake and Ohio Canal

More than half of turtle species worldwide are threatened because of habitat loss, invasive species, environmental pollution, disease, unsustainable use, and global climate change. However, some turtles are capable of existing in highly modified habitats, including structures designed to benefit human populations such as reservoirs and canal systems. Examining turtle distributions in large canal systems can inform conservation plans protecting turtle populations within a potential reservoir network and expand our understanding of underlying mechanisms regulating populations. We conducted spatial capture–recapture on turtles inhabiting sections of the Chesapeake and Ohio Canal. We developed a Bayesian spatial capture–recapture model to estimate densities, sex ratios, and associated capture probability parameters for Chrysemys picta (Painted Turtle), Chelydra serpentina (Common Snapping Turtle), Sternotherus odoratus (Eastern Musk Turtle), and Pseudemys rubriventris (Red-Bellied Turtle) captured at 12 sites along 28 km of the canal. We examined the impact of canal depth and forest cover on population densities and the variation in capture probability between sites and sampling days. We found population densities to vary between sites and the associated sex ratios to vary between species, as did the effect of depth and forest cover. Overall capture rates decreased each day, but there was trap-happy behavior from all species except S. odoratus. Our information can set a baseline for understanding turtle populations and inform management in the Chesapeake and Ohio Canal National Historical Park. It is also one of the first studies to establish methods for using new spatial capture–recapture to quantify densities and aquatic space use of turtles.

Microbial Communities in Chesapeake & Ohio Canal National Historical Park and Their Function as Indicators of Water Quality

The objective of this study was to establish meaningful relationships between prokaryotic community profiles and water quality parameters in different water bodies (spring, stream, cave, and mine) in the middle reach of the Chesapeake & Ohio Canal National Historic Park (C&O), Maryland. The microbial profiles in the water samples were determined using metagenomic analysis. The relationships between microbial phylogenetic profiles and water quality parameters were investigated using principal component analysis (PCA) and redundancy analysis (RDA). The most abundant phyla identified in most samples were Proteobacteria (55.4%), Bacteroidetes (12.3%), Actinobacteria (10.6%), Firmicutes (2.4%), Planktomycetes (1.8%), Verrucomicrobia (1.5%), Chloroflexi (1.5%), and Acidobacteria (1.3%), which are major bacterial and archaeal groups typically observed in natural freshwater environments. PCA showed that water chemistry was determined primarily by the geology of the site and the type of water source (i.e., spring, stream, cave, or mine). Most samples located in carbonate formations correlated with high alkalinity, inorganic carbon, and calcium, representing the typical karstic geochemistry. RDA shows that pH, electrical conductivity, temperature and nutrients including nitrate, phosphate, and sulfate, were significant determinants of the microbial ecology.

Design tradeoffs in long‐term research for stream salamanders

ABSTRACTLong‐term research programs can benefit from early and periodic evaluation of their ability to meet stated objectives. In particular, consideration of the spatial allocation of effort is key. We sampled 4 species of stream salamanders intensively for 2 years (2010–2011) in the Chesapeake and Ohio Canal National Historical Park, Maryland, USA to evaluate alternative distributions of sampling locations within stream networks, and then evaluated via simulation the ability of multiple survey designs to detect declines in occupancy and to estimate dynamic parameters (colonization, extinction) over 5 years for 2 species. We expected that fine‐scale microhabitat variables (e.g., cobble, detritus) would be the strongest determinants of occupancy for each of the 4 species; however, we found greater support for all species for models including variables describing position within the stream network, stream size, or stream microhabitat. A monitoring design focused on headwater sections had greater power to detect changes in occupancy and the dynamic parameters in each of 3 scenarios for the dusky salamander (Desmognathus fuscus) and red salamander (Pseudotriton ruber). Results for transect length were more variable, but across all species and scenarios, 25‐m transects are most suitable as a balance between maximizing detection probability and describing colonization and extinction. These results inform sampling design and provide a general framework for setting appropriate goals, effort, and duration in the initial planning stages of research programs on stream salamanders in the eastern United States. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Evaluating the predictive abilities of community occupancy models using AUC while accounting for imperfect detection

The ability to accurately predict patterns of species' occurrences is fundamental to the successful management of animal communities. To determine optimal management strategies, it is essential to understand species-habitat relationships and how species habitat use is related to natural or human-induced environmental changes. Using five years of monitoring data in the Chesapeake and Ohio Canal National Historical Park, Maryland, USA, we developed four multispecies hierarchical models for estimating amphibian wetland use that account for imperfect detection during sampling. The models were designed to determine which factors (wetland habitat characteristics, annual trend effects, spring/summer precipitation, and previous wetland occupancy) were most important for predicting future habitat use. We used the models to make predictions about species occurrences in sampled and unsampled wetlands and evaluated model projections using additional data. Using a Bayesian approach, we calculated a posterior distribution of receiver operating characteristic area under the curve (ROC AUC) values, which allowed us to explicitly quantify the uncertainty in the quality of our predictions and to account for false negatives in the evaluation data set. We found that wetland hydroperiod (the length of time that a wetland holds water), as well as the occurrence state in the prior year, were generally the most important factors in determining occupancy. The model with habitat-only covariates predicted species occurrences well; however, knowledge of wetland use in the previous year significantly improved predictive ability at the community level and for two of 12 species/species complexes. Our results demonstrate the utility of multispecies models for understanding which factors affect species habitat use of an entire community (of species) and provide an improved methodology using AUC that is helpful for quantifying the uncertainty in model predictions while explicitly accounting for detection biases.

Reintroduction of Federally Endangered Harperella (Harperella nodosumRose) in Flood-Prone, Artificial, and Natural Habitats

Harperella (Harperella nodosum) is the only federally listed endangered plant species in the Chesapeake and Ohio Canal National Historical Park (C&O Canal NHP) in the National Park Service in Maryland and one of four federally listed endangered plant species in West Virginia. This paper contrasts unsuccessful and successful efforts to reintroduce harperella seedlings in the main stem of the flood-prone Potomac River and on opposite sides of the river in damp sites in western Maryland and in streams in northeastern West Virginia. The reintroduction efforts in Maryland unsuccessfully transplanted seedlings on cobble bars on the Maryland side of the Potomac River and in artificial sites in the prism of the C&O Canal where harperella had never been found; the reintroduction efforts in West Virginia successfully transplanted seedlings on cobble bars in two tributaries of the Potomac River in West Virginia where harperella populations once flourished but in the last decade or so had been decimated by floods and ice damage. This investigation has contributed to defining harperella's life-cycle characteristics and ecological requirements. The data and observations presented can be used as a guide for reintroducing harperella seedlings and, by extension, other semiaquatic plant species into appropriate sites.

Geology of the Chesapeake and Ohio Canal National Historical Park and Potomac River Corridor, District of Columbia, Maryland, West Virginia, and Virginia. By Scott Southworth, David K. Brezinski, Randall C. Orndorff, John E. Repetski, and Danielle M. Denenny. Reston, Virginia: U.S. Geological Service, 2008. U.S. Geological Survey Professional Paper 1691. x + 144 pp. Illustrations, photographs, maps, and bibliography. Paper.

<i>Geology of the Chesapeake and Ohio Canal National Historical Park and Potomac River Corridor, District of Columbia, Maryland, West Virginia, and Virginia</i>. By Scott Southworth, David K. Brezinski, Randall C. Orndorff, John E. Repetski, and Danielle M. Denenny. Reston, Virginia: U.S. Geological Service, 2008. U.S. Geological Survey Professional Paper 1691. x + 144 pp. Illustrations, photographs, maps, and bibliography. Paper.