Andrew Ray

• PhD
• Ecologist at National Park Service

Environmental impacts from surface mining can extend beyond the lifetime of mining operations, persist for decades prior to formal clean-up, and span multiple jurisdictional boundaries. Using a case study from Soda Butte Creek which enters Yellowstone National Park, we demonstrate how existing datasets and longitudinal studies can be integrated to...

Long-term drought caused Lake Powell, a reservoir on the Colorado River (USA), to decline to its lowest elevation in >50 years during 2022–2023, allowing warm water to pass through intakes of Glen Canyon Dam and facilitating invasion by non-native Smallmouth Bass ( Micropterus dolomieu ). Establishment of bass downstream of the dam could threaten p...

We assessed amphibian diversity, rarity, and threats across the National Park System (U.S.A.), which covers 3.5% of the country and 12% of federal lands. At least 230 of 354 (65%) amphibian species documented in the country occur on National Park Service lands. Of species in parks, 17% are at-risk globally and 20% are uncategorized, reflecting stil...

National parks and other protected areas are important for preserving landscapes and biodiversity worldwide. An essential component of the mission of the United States (U.S.) National Park Service (NPS) requires understanding and maintaining accurate inventories of species on protected lands. We describe a new, national-scale synthesis of amphibian...

There is abundant evidence that genetic and morphological diversity is present among widespread species. This variation results from multiple processes, such as interruptions in gene flow or local adaptation. In Crater Lake National Park, a volcanic lake formed 7,700 y ago. Rough-skinned Newts (Taricha granulosa) subsequently colonized Crater Lake,...

Have you ever wondered how “cold-blooded” animals like amphibians (frogs, toads, and salamanders) survive the winter without fur or feathers to keep them warm? Yellowstone National Park’s amphibians have found ways to stay alive during the cold winter months. These animals have evolved various coping strategies, from burrowing underground, to livin...

Why does Earth have such an incredible variety of plants and animals? One little newt helps tell the story. In Crater Lake, the world’s clearest lake, a uniquely colored newt was discovered. Early explorers named it the Mazama newt. For more than 100 years, the newt has been considered a subspecies of the more common rough-skinned newt. A “subspeci...

Protected areas like national parks are essential elements of conservation because they limit human influence on the landscape, which protects biodiversity and ecosystem function. The role of national parks in conservation, however, often goes far beyond limiting human influence. The U.S. National Park Service and its system of land units contribut...

Widespread amphibian declines were well documented at the end of the 20th century, raising concerns about the need to identify individual and interactive contributors to this global trend. At the same time, there was growing interest in the use of amphibians as ecological indicators. In the United States, wetland and amphibian monitoring programs w...

In the U.S. National Park Service, the presence and diversity of wetlands and wetland-dependent groups (e.g., amphibians) serve as key ecological indicators for tracking the health of national park units. Historically, wetlands in remote and mountainous regions have been difficult and labor-intensive to monitor, especially at landscape scales. Here...

Successful eutrophication control strategies need to address the limiting nutrient. We conducted a battery of laboratory and in situ nutrient-limitation tests with waters collected from 9 streams in an agricultural region of the upper Snake River basin, Idaho, USA. Laboratory tests used the green alga Raphidocelis subcapitata, the macrophyte Lemna...

There is growing interest in the use of carbon dioxide (CO 2 ) as a management tool for controlling invasive fishes. However, there is limited published data on susceptibility of many commonly encountered species to elevated CO 2 concentrations. Our objective was to estimate the 24-h LC 50 and LC 95 of four fishes (Rainbow Trout Oncorhynchus mykiss...

Natural history note on Plains Spadefoot (Spea bombifrons) leucism in Yellowstone National Park.

In Grand Teton and Yellowstone national parks wetlands offer critical habitat and play a key role in supporting biological diversity. The shallow depths and small size of many palustrine wetlands in these protected areas and elsewhere make them vulnerable to changes in climate compared with larger and deeper aquatic habitats. Here, we use a simple...

Discerning the determinants of species occurrence across landscapes is fundamental to their conservation and management. In spatially and climatologically complex landscapes, explaining the dynamics of occurrence can lead to improved understanding of short‐ vs. long‐term trends and offer novel insight on local vs. regional change. We examined the c...

Changing climate will impact species' ranges only when environmental variability directly impacts the demography of local populations. However, measurement of demographic responses to climate change has largely been limited to single species and locations. Here we show that amphibian communities are responsive to climatic variability, using >500,00...

Wetlands in the Prairie Pothole Region (PPR) of North America support macroinvertebrate communities that are integral to local food webs and important to breeding waterfowl. Macroinvertebrates in PPR wetlands are primarily generalists and well adapted to within and among year changes in water permanence and salinity. The Williston Basin, a major so...

In 2015, National Park Service scientists teamed with the Montana Department of Environmental Quality to conduct a comprehensive characterization of water quality in Soda Butte Creek. Soda Butte Creek is a tributary of the Lamar River whose water quality was impaired by historical mining activity near Cooke City, Montana. This investigation followe...

The signal crayfish (Pacifastacus leniusculus) was introduced to Crater Lake in 1915 and now threatens the local extinction of an endemic salamander, the Mazama newt (Taricha granulosa mazamae). More than a century after their introduction, crayfish have expanded in distribution to occupy nearly 80% of the lakeshore. Although newts remain in uninva...

To restore native fish populations, fisheries programs often depend on active removal of aquatic invasive species. Chemical removal can be an effective method of eliminating aquatic invasive species, but chemicals can induce mortality in nontarget organisms and persist in the environment. Carbon dioxide (CO2) is an emerging alternative to tradition...

Despite the importance of hydrologic regimes to the phenology, demography, and abundance of fishes such as salmonids, there have been surprisingly few syntheses that holistically assess regional, species-specific trends in hydrologic regimes within a framework of climate change. Here, we consider hydrologic regimes within the Greater Yellowstone Ar...

Whitebark pine (Pinus albicaulis) forests in the western United States have been adversely affected by an exotic pathogen (Cronartium ribicola, causal agent of white pine blister rust), insect outbreaks (Dendroctonus ponderosae, mountain pine beetle), and drought. We monitored individual trees from 2004 to 2013 and characterized stand-level biophys...

Energy production in the Williston Basin, USA, results in the coproduction of highly saline, sodium chloride-dominated water (brine). The Prairie Pothole Region (PPR) overlies the northeastern portion of the Williston Basin. Although PPR wetlands span a range of salinity, the dominant salt is sodium sulfate, and salinities are much lower than brine...

Freshwater wetlands are particularly vulnerable to climate change. Specifically, changes in temperature, precipitation, and evapotranspiration (i.e., climate drivers) are likely to alter flooding regimes of wetlands and affect the vital rates, abundance, and distributions of wetland-dependent species. Amphibians may be among the most climate-sensit...

Since amphibian declines were first proposed as a global phenomenon over a quarter century ago, the conservation community has made little progress in halting or reversing these trends. The early search for a “smoking gun” was replaced with the expectation that declines are caused by multiple drivers. While field observations and experiments have i...

Knowledge of climatic variability at small spatial extents (< 50 km) is needed to assess vulnerabilities of biological reserves to climate change. We used empirical and modeled weather station data to test if climate change has increased the synchrony of surface air temperatures among 50 sites within the Greater Yellowstone Area (GYA) of the interi...

The signal crayfish (Pacifastacus leniusculus) was introduced to Crater Lake in 1915 and is now displacing a native salamander. Before the introduction of this crayfish species, no crayfish existed in the lake. A proposed subspecies of the rough-skinned newt (Taricha granulosa), the Mazama newt (T. granulosa mazamae) is reportedly endemic to Crater...

Managers often nest sections of water bodies together into assessment units (AUs) to monitor and assess water quality criteria. Ideally, AUs represent an extent of waters with similar ecological, watershed, habitat and land-use conditions and no overlapping characteristics with other waters. In the United States, AUs are typically based on politica...

Tetrodotoxin (TTX) is a low molecular weight neurotoxin that is found in a wide variety of taxa. Tetrodotoxin blocks voltage-gated sodium channels, preventing the propagation of action potentials and inducing paralysis in susceptible animals. Taricha granulosa have been documented to possess TTX in high quantities and are preyed upon by snakes of t...

Endangered woundfin Plagopterus argentissimus embryos and larvae were exposed to artificial ultraviolet-B (UV-B) radiation to directly examine the effects on mortality. The experiment was part of a project assisting the Virgin River Resource Management and Recovery Program's efforts to increase hatchery production of this endangered fish. The UV-B...

We describe and evaluate a laboratory bioassay that uses Lemna minor L. and attached epiphytes to characterize the status of ambient and nutrient-enriched water from the Portneuf River, Idaho. Specifically, we measured morphological (number of fronds, longest surface axis, and root length) and population-level (number of plants and dry mass) respon...

Amphibians have been selected as a “vital sign” by several National Park Service (NPS) Inventory and Monitoring (I&M) networks. An eight-year amphibian monitoring data set provided opportunities to examine spatial and temporal patterns in amphibian breeding richness and wetland desiccation across Yellowstone and Grand Teton National Parks. Amphibia...

Early detection of aquatic invasive species is a critical task for management of aquatic ecosystems. This task is hindered by the difficulty and cost of surveying aquatic systems thoroughly. The New Zealand mudsnail (Potamopyrgus antipodarum) is a small, invasive parthenogenic mollusk that can reach very high population densities and severely affec...

Exotic plant invasions into riparia often result in shifts in vegetative composition, altered stream function, and cascading effects to biota at multiple scales. Characterizing the distribution patterns of exotic plants is an important step in directing targeted research to identify mechanisms of invasion and potential management strategies. In thi...

Current management strategies for the control and suppression of the American Bullfrog (Lithobates catesbeianus = Rana catesbeiana Shaw) and other invasive amphibians have had minimal effect on their abundance and distribution. This study evaluates the effects of carbon dioxide (CO2) on pre- and prometamorphic Bullfrog larvae. Bullfrogs are a model...

Vegetative diversity metrics are often used to characterize wetland restoration success. Here we examine whether other important vegetative traits (nutrient standing stocks and tissue nutrient concentrations) can improve our understanding of the structure of restored and reference wetlands and aid in the assessment of functional equivalency. We foc...

This study examined how free-floating macrophyte cover (principally composed of duckweeds [Lemna spp.]) and prevalence of floating filamentous algal mats (metaphyton) varied within and among lakes within three reaches of the Upper Mississippi River. Data were collected using standard sampling approaches over the period 1998 to 2008. Duckweed cover...

Aquatic invasive species present unique ecological threats. Pervasive habitat modification and the ease of global transportation have facilitated their spread, and they are now a leading threat to native species and to the functioning of entire ecosystems. Various researchers have suggested steps to take in treating aquatic invasive species, and in...

Pre-restoration studies typically focus on physical habitat, rather than the food-base that supports aquatic species. However, both food and habitat are necessary to support the species that habitat restoration is frequently aimed at recovering. Here we evaluate if and how the productivity of the food-base that supports fish production is impaired...

Beavers (Castor canadensis Kuhl.) are keystone species that dramatically alter nutrient cycles and food webs in aquatic and terrestrial ecosystems by modifying their hydrology and selectively removing riparian trees. We documented macrophyte succession in 36 beaver ponds ranging from 4 to over 40 years old. We used impounded bogs, because they were...

Even though photosynthesis is an obligatory part of the science curriculum, research has shown that students often have a poor understanding of it. The authors advocate that classroom coverage of the topic of photosynthesis should include not only its biochemical properties but also the role of photosynthesis or photosynthetic organisms in matter c...

The Fairview Constructed Wetland, a complex of replicated wet meadow (primary filter) and shallow marsh (shallow wetland) cells, was built in southeast Idaho in 1999 and planted with seven native plant species. The development of aboveground biomass and root mass and the accumulation of litter for each cell and for each species are described here....

We examined the vegetative pools of carbon (C), nitrogen (N), and phosphorus (P) in constructed wetlands receiving irrigation return flows in southeastern Idaho. Seven native wetland plant species were introduced into the wetlands in 1999. Carex nebrascensis, Eleocharis palustris, Juncus balticus, and Scheonoplectus maritimus were planted in replic...

Flooding has been described as one of the primary factors affecting arbuscular mycorrhizal (AM) colonization in wetlands. We investigated the effect of water-level fluctuations on AM colonization of Typha latifolia L. using an experimental wetland in southeastern Idaho, USA that received intermittent flows. Unlike previous research that has examine...

Previous research has demonstrated that beavers (Castor canadensis) dramatically alter fish habitat in streams by their dam-building activities. Although less well-known, beavers also flood closed peatlands by damming seepage rather than streamflow. Our study focuses on the establishment of fish communities in isolated beaver ponds created in small...

We investigated the impact of arbuscular mycorrhizae fungi on common cattails (Typha latifolia), a ubiquitous wetland plant species. The mycorrhizal relationship, which involves the exchange of fungal-acquired nutrients and plant-produced carbon, has been shown to elicit a range of physiological and biochemical responses in host plants. Growth, pho...

Thesis (M.S.)--Northern Michigan University, 1999. Includes bibliographical references (leaves 29-36).