Springs Monitoring at Tuzigoot National Monument: 2024
Elora Ormand, Elizabeth Schnaubelt, Cheryl McIntyre, Andy Hubbard
Edited by Tani Hubbard
Please cite this publication as:
Ormand, E., E. Schnaubelt, C. McIntyre, and A. Hubbard. 2026. Springs Monitoring at Tuzigoot National Monument: 2024. Science Report NPS/SR—2026/451. National Park Service, Fort Collins, Colorado. https://doi.org/10.36967/2318595
Abstract
The Sonoran Desert Inventory and Monitoring Network monitors one spring, Shea Spring, each year at Tuzigoot National Monument, Arizona. We assess the condition of the site, measure spring discharge and wetted extent (area that contained water), collect core water quality and water chemistry data, note the wetland plants and invasive plants and animals present, and sample for environmental DNA (eDNA) to inventory springs for rare species, invasive species, and pathogens. Each spring is somewhat unique, and Arizona has not adopted water quality standards that apply across the diversity of springs in the state. Therefore, we continue to collect water quality data at the spring to form a baseline reference of natural variance. We collected a total of 11 water samples for eDNA testing from Shea Spring (a rheocrene spring) and the adjacent Tavasci Marsh. We detected American bullfrog in nine samples and chytrid fungus in five samples. Both of these target organisms were present in Shea Spring and the marsh. Woodhouse’s toad was detected in one sample from the marsh. Shea Spring emerges from the bottom of a clear pool surrounded by cattails and feeds directly into the adjacent marsh. The spring had water when we visited in 2024, but persistence data are not available for the remainder of the year. In most years measured, the spring had water year round. Burned trees are present around the site from a fire in 2023, and there is evidence that beavers are using the site. In addition to the eDNA evidence of American bullfrog, we saw bullfrogs in the spring for the first time in 2024, though they have been commonly detected in Tavasci Marsh in prior years. We found red brome and Bermudagrass (invasive plants) at the spring, and wetland plants included cattail, horsetail, and at least two Carex species (sedge/rush). We do not collect wetted extent data at this spring to minimize disturbance to the site, and because it is on one corner of the larger marsh, making it difficult to define.
NPS
Background
Springs, seeps, and tinajas (discrete pools in a rock basin or impoundments in bedrock) are small, relatively rare biodiversity hotspots in arid lands. They are the primary connection between groundwater and surface water and are important water sources for plants and animals. At Tuzigoot National Monument, Sonoran Desert Network scientists study how ecosystems may be changing by taking measurements of key resources, or “vital signs,” year after year—much as a doctor keeps track of a patient’s vital signs. This long-term ecological monitoring provides early warnings of potential problems, allowing managers to mitigate them before they become worse. We monitor one spring in Tuzigoot National Monument each year. The most important questions we ask are about persistence (How long was there water in the spring?) and water quantity (How much water was in the spring?).
Climate change is an emerging influence on springs in the American Southwest. Possible changes include increased air temperatures, evaporation rates, and drought intensity; more frequent and extreme rainfall and heat events; and potentially reduced precipitation in the winter and spring. These changes may cause springs to experience reduced flow or even go dry, which may disrupt ecological functions, reduce species diversity, and negatively impact visitor experience.
Springs reporting is by calendar year starting in 2024. Prior to 2024, springs data were summarized by water year (WY), which ran from October through September (e.g., WY2023 started in October 2022 and went through September 2023). In 2024, springs sampling at Tuzigoot National Monument occurred on 14 May. Water persistence is monitored continuously throughout the year, but in this report we only present 2024 persistence data up to the sampling visit date for Shea Spring.
Methods
Sonoran Desert Network springs monitoring is organized into the four modules described below (see McIntyre et al. 2018 for additional details) and eDNA inventories. All data have undergone certification processes to ensure they have been verified and validated for accuracy, are complete, and are fully documented. Data used in this report are available to park staff on the NPS DataStore and can be provided upon request.
Site Characterization
This module provides context for interpreting change in the other modules. We record GPS locations, draw a site diagram, and describe the spring type (e.g., helocrene, limnocrene, rheocrene, or tinaja) and its associated vegetation in this module. Helocrene springs emerge as low-gradient wetlands, limnocrene springs emerge as pools, and rheocrene springs emerge as flowing streams. This module is completed once every five years or after significant events.
Site Condition
We estimate the level of natural and anthropogenic disturbances and the level of stress on vegetation and soils at the spring on a scale of 1–4, where 1 = undisturbed, 2 = slightly disturbed, 3 = moderately disturbed, and 4 = highly disturbed. Types of natural disturbances can include flooding, drying, fire, wildlife impacts, windthrow of trees and shrubs, beaver activity, and insect infestations. Anthropogenic disturbances can include roads, off-highway vehicle trails, hiking trails, livestock and feral-animal impacts, removal of invasive non-native plants, flow modification, and other evidence of human use of the spring site. We take repeat photographs from the same location and perspective to show the spring and its landscape context. We note the presence of certain obligate wetland plant species (plant species that almost always occur only in wetlands), facultative wetland plant species (plant species that usually occur in wetlands, but also occur in other habitats), and invasive non-native crayfish and American bullfrog (Rana catesbeiana). We also record the density of invasive non-native plants using a qualitative scale (1–5 plants, scattered patches, evenly distributed patches, or a matrix). We complete the site condition module during each springs monitoring visit.
Water Quantity
We measure the persistence of surface water, amount of spring discharge, and wetted extent (area that contained water). To estimate persistence, we analyze the variance of temperature measurements taken by two logging thermometers placed at or near the orifice (spring opening). Because water mediates variation in diurnal temperatures, data from a submerged sensor will show less daily variation than data from an exposed, open-air sensor; this tells us when the spring was wet or dry. Surface discharge is measured with a timed sample of water volume. Wetted extent is a systematic measurement of the physical length (up to 100 m), width, and depth of surface water. It is assessed using a technique for either standing water (e.g., limnocrene and helocrene springs) or flowing water (e.g., rheocrene springs). We complete discharge and wetted extent measurements during each visit when possible. Water persistence measurements are continuous throughout the year.
Water Quality
We measure core water quality and water chemistry parameters. Core water quality parameters include water temperature, pH, specific conductivity (a measure of dissolved compounds and contaminants), dissolved oxygen (how much oxygen is present in the water), and total dissolved solids (an indicator of potentially undesirable compounds). Discrete measurements of these parameters are collected with a multiparameter meter. If the meter fails calibration checks, we do not present data. Water chemistry is assessed by collecting surface water samples and estimating the concentration of major ions with a photometer in the field. These parameters are collected at one or more sampling locations within a spring, but we only present data for the primary sampling location. Each perennial spring is somewhat unique, and Arizona has not adopted applicable water quality standards for most perennial springs, including Shea Spring. Ongoing, long-term data collection at each spring will improve our understanding of the natural range in water quality and water chemistry parameters for a given site. We complete the water quality module during each visit when possible. The total number of measurements value we present in the data tables is across all years and may reflect multiple measurements taken in a single year and missing values in other years for a variety of reasons.
eDNA Inventory of Rare Species, Invasive Species, and Pathogens
We inventory rare species, invasive species, and pathogens in perennial springs using environmental DNA (eDNA) techniques. One or more 5-liter water samples are collected and filtered (using a 5 µm self-preserving mesh filter) using a Smith Root Citizen Science Pump. Eleven total water samples were collected and filtered from the spring or surrounding Tavasci Marsh at Tuzigoot National Monument in 2024. Samples are preserved in ethanol prior to DNA extraction and analysis by the Goldberg Lab at Washington State University.
Target Organisms for the eDNA Project
The invasive non-native American bullfrog (Rana catesbeiana), which is present in Tavasci Marsh adjacent to the monitored spring at Tuzigoot National Monument. Until 2024, this species had not been seen at Shea Spring, but it is likely it was there in prior years since the spring is on the side of the marsh that has bullfrogs.
The pathogen chytrid fungus (Batrachochytrium dendrobatidis), a major threat to amphibians globally that is currently expanding in the American Southwest but has not been previously detected in the park. Chytrid fungus is often carried by American bullfrog which have a degree of resistance to the pathogen.
Ranaviruses, pathogens that can infect amphibians and produce 90–100% mortality in tadpoles and adults and can persist in affected wetlands. Ranaviruses have not been previously detected at the park, although American bullfrog is a known vector of ranaviruses into wetland ecosystems.
The native Chiricahua leopard frog (Rana chiricahuensis), a federally designated threatened species with a historical range that includes Tuzigoot National Monument, though the current known range and critical habitat is south of the park (Schmidt et al. 2005). However, this species has been recently detected nearby on the Prescott National Forest (A. Owens, personal communication).
The native lowland leopard frog (Rana yavapaiensis), a species of conservation concern that has been historically found within the park but has not been detected recently (Schmidt et al. 2005).
The native Woodhouse’s toad (Bufo woodhousii), a relatively common species in the region that seems to be able to coexist with American bullfrog. This species has been previously detected in the park (Schmidt et al. 2005).
The native aquatic northern Mexican garter snake (Thamnophis eques megalops), a federally designated threatened species that is known to occur within Tavasci Marsh (Arizona Game and Fish Department, personal communication). Designated critical habitat includes the nearby Verde River, including the reach through the park.
The native jaguar (Panthera onca), a federally designated endangered species that was historically found within the park, although current designated critical habitat for jaguar recovery is located well south of the Verde Valley.
Results
Shea Spring
Shea Spring (Figure 1) is a limnocrene spring (a spring that emerges as one or more lentic pools). Water bubbles up from the sandy bottom of a clear pool and feeds directly to the adjacent Tavasci Marsh. Dense cattails surround the site. The 2024 visit occurred on 14 May, and the spring contained water.
NPS
Site Condition
In 2024, we rated Shea Spring as slightly disturbed by hiking trails because a hiking trail leads to the site, and slightly disturbed by fire based on burned trees from the 2023 fire near the spring (the spring was rated undisturbed to highly disturbed by fire in the past). Similar to previous years, we rated the site slightly disturbed by beaver activity with beaver chew marks on a dead juniper tree at the site (Figure 2). No other natural or human-caused disturbances were observed at Shea Spring in 2024.
NPS
In 2024, we detected the invasive non-native American bullfrog (Rana catesbeiana) in the eDNA samples. This is the first time we have detected bullfrogs at Shea Spring using any method, though we have commonly detected them throughout the adjacent Tavasci Marsh in eDNA and visually. We also observed two species of invasive non-native plants at the spring: scattered patches of red brome (Bromus rubens, 1–5 plants to scattered patches previously observed in 2019–2023) and a matrix of Bermudagrass (Cynodon dactylon, evenly distributed patches to a matrix previously observed in three monitoring years between 2017 and 2023).
We observed four species of obligate/facultative wetland plants at Shea Spring in 2024: a species of the cattail family (Typhaceae, a grass previously observed in 2017–2022); horsetail (Equisetum sp., a forb previously observed in 2017–2023); and at least two species of sedge/rush (Carex sp., one was observed in 2017–2023 and the other observed in 2019–2022).
eDNA Inventory of Rare Species, Invasive Species, and Pathogens
Three water samples were collected directly from Shea Spring on 14 May 2024. An additional eight samples were taken throughout the surrounding Tavasci Marsh. Of the 11 samples, nine detected American bullfrog, five detected chytrid fungus, and one detected Woodhouse’s toad. American bullfrog and chytrid fungus were detected at both the spring and the marsh, while Woodhouse’s toad was detected only in the marsh.
Water Quantity
Sensors are deployed and data are downloaded during our annual visit; the dates of these visits are indicated by black diamonds in the persistence graph (Figure 3). Temperature sensor data are missing, so there is no estimate of persistence for 2024. In prior years, the spring was wetted (contained water) for 71–100% of the days measured across entire years. However, the recorded dry periods in 2017 and 2018 were likely wetted but appear dry in the data because the sensor was probably pulled from the water by an animal or a flood event.
NPS
Discharge was not measurable at Shea Spring in 2024, as in past years. No prior discharge measurements are available, as the spring has always discharged into the surrounding Tavasci Marsh in a diffuse fashion through multiple orifices, which makes it nearly impossible to measure discharge accurately. Wetted extent data are not collected at this spring to minimize disturbance to the site and because the spring is on one corner of the larger marsh, making it difficult to define.
Water Quality
Core water quality (Table 1) and water chemistry (Table 2) data were collected at the primary sampling location. In 2024, the values for pH, specific conductivity, and temperature were within the ranges recorded in prior years, while the value for total dissolved solids was slightly higher and dissolved oxygen was lower than in previous years. The values for magnesium and potassium were less than what was recorded in prior years, while alkalinity, calcium, chloride and sulphate were all within the ranges of prior measurements.
| Sampling Location | Parameter | 2024 Value (Range of Prior Values) |
Prior Years Measured (# of Measurements) |
|---|---|---|---|
| 001 | Dissolved oxygen (mg/L) | 5.75 (6.20–7.23) | 2017–2023 (6) |
| 001 | pH | 7.33 (6.06–7.47) | 2017–2023 (6) |
| 001 | Specific conductivity (µS/cm) | 568.0 (549.0–677.4) | 2017–2023 (6) |
| 001 | Temperature (°C) | 20.3 (19.0–20.3) | 2017–2023 (7) |
| 001 | Total dissolved solids (mg/L) | 369 (357–364) | 2017–2023 (6) |
| Sampling Location | Parameter | 2024 Value (Range of Prior Values) |
Prior Years Measured (# of Measurements) |
|---|---|---|---|
| 001 | Alkalinity (CaCO3) | 235 (185–255) | 2017–2023 (6) |
| 001 | Calcium (Ca) | 54 (36–62) | 2017–2023 (6) |
| 001 | Chloride (Cl) | 23 (17–44) | 2017–2023 (6) |
| 001 | Magnesium (Mg) | 20 (23–43) | 2017–2023 (6) |
| 001 | Potassium (K) | 1.0 (1.9–3.1) | 2017–2023 (6) |
| 001 | Sulphate (SO4) | 0 (0–5) | 2017–2023 (6) |
Past Reports
Previous annual reports can be found at the following links:
Literature Cited
McIntyre, C., K. Gallo, E. Gwilliam, J.A. Hubbard, J. Christian, K. Bonebrake, G. Goodrum, M. Podolinsky, L. Palacios, et al. 2018. Springs, seeps, and tinajas monitoring protocol: Chihuahuan and Sonoran Desert Networks. Natural Resource Report. NPS/CHDN/NRR—2018/1796. National Park Service. Fort Collins, Colorado. https://irma.nps.gov/DataStore/Reference/Profile/2257245
Schmidt, C.A., B.F. Powell, and W.L. Halvorson. 2005. Vascular plant and vertebrate inventory of Tuzigoot National Monument. U.S. Geological Survey (USGS) Open-File Report. 2005-1347. USGS, Southwest Biological Science Center, Sonoran Desert Research Station, University of Arizona. Tucson, Arizona. https://irma.nps.gov/DataStore/Reference/Profile/646988
Author Information
Elora Ormand 1
Elizabeth Schnaubelt 1
Cheryl McIntyre 1 
https://orcid.org/0000-0001-7554-7586
Andy Hubbard 1 https://orcid.org/0000-0002-4223-7730
Edited by Tani Hubbard 2
https://orcid.org/0009-0009-8777-4773
1
National Park Service
Sonoran Desert Inventory and Monitoring Network
12661 E. Broadway Blvd.
Tucson, Arizona
2
Northern Rockies Conservation Cooperative and National Park
Service
12661 E. Broadway Blvd.
Tucson, Arizona
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