K. Jones (USGS) extracting a water sample for pesticide analysis at Pesticide Fate Research Laboratory. Photo by: R. Todd.
The collaborative design which joins wildlife biologists and hydrologists enables ARMI to ask the kinds of questions it does about the environmental variables that affect amphibians in a truly integrated manner. Understanding how water quality, quantity, or timing affects amphibians is a critical component of ARMI research.
A hydrologist is associated with each ARMI region and works with the ARMI PI to develop and implement research and monitoring projects. These collaborations enable ARMI to ask questions about how water quality (e.g., nutrients, agro-chemicals, acidification), water budgets (e.g., ground and surface water models), storm surge impacts, or other hydrologic conditions can affect amphibian life cycles, disease transport, or habitat quality.
USGS Toxics Substances Hydrology program
ARMI Products on Water
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Geographically Isolated Wetlands:
Authors: Mushet, DM, Calhoun, AJK, Alexander, LC, Cohen, MJ, DeKeyser, ES, Fowler, L, Lane, CR, Lang, MW, Rains, MC, Walls, SC
We explore the category geographically isolated
wetlands(GIWs; i.e., wetlands completely surrounded by
uplands at the local scale) as used in the wetland sciences.
As currently used, the GIW category (1) hampers scientific
efforts by obscuring important hydrological and ecological
differences among multiple wetland functional types, (2)
aggregates wetlands in a manner not reflective of regulatory
and management information needs, (3) implies wetlands so
described are in some way isolated, an often incorrect
implication, (4) is inconsistent with more broadly used and
accepted concepts of geographic isolation, and (5) has
injected unnecessary confusion into scientific investigations
and discussions. Instead, we suggest other wetland classification
systems offer more informative alternatives. For
example, hydrogeomorphic (HGM) classes based on wellestablished
scientific definitions account for wetland functional
diversity thereby facilitating explorations into
questions of connectivity without an a priori designation of
isolation. Additionally, an HGM-type approach could be
used in combination with terms reflective of current regulatory
or policymaking needs. For those rare cases in which
the condition of being surrounded by uplands is the relevant
distinguishing characteristic, use of terminology that does
not unnecessarily imply isolation (e.g., upland embedded
wetlands) would help alleviate much confusion caused by
the geographically isolated wetlands misonomer.
Glyphosate and its degradation product AMPA occur frequently and widely in U.S. soils, surface water, groundwater, and precipitation
Author: Battaglin W, Meyer M, Kuivila K, Dietze J | Date: 2014 | Outlet: Journal of the American Water Resources Association 50(2): 275-290. | Format: URL
Glyphosate use in the US increased from less than 5,000 to more than 80,000 metric tons per year between 1987 and 2007. Glyphosate is popular due to its ease of use on soybean, cotton and corn crops that are genetically modified to tolerate it, utility in no-till farming practices, utility in urban areas, and the perception that it has low toxicity and little mobility in the environment. This compilation is the largest and most comprehensive assessment of the environmental occurrence of glyphosate and AMPA in the US conducted to date, summarizing the results of 3,732 water and sediment and 1,018 quality-assurance samples collected between 2001 and 2010 from 38 States. Results indicate that glyphosate and AMPA are usually detected together, mobile, and occur widely in the environment. Glyphosate was detected without AMPA in only 2.3% of samples, whereas AMPA was detected without glyphosate in 17.9% of samples. Glyphosate and AMPA were detected frequently in soils and sediment, ditches and drains, precipitation, rivers, and streams; and less frequently in lakes, ponds, and wetlands; soil water; and groundwater. Concentrations of glyphosate were below levels of concern for humans or wildlife; however, pesticides are often detected in mixtures. Ecosystem effects of chronic low-level exposures to pesticide mixtures are uncertain. The environmental health risk of low-level detections of glyphosate, AMPA, and associated adjuvants and mixtures remain to be determined.
The effects of hydropattern and predator communities on amphibian occupancy
Authors: Amburgey S, Bailey L, Murphy M, Muths E, Funk W | Date: 2014-09-23 | Outlet: Canadian Journal of Zoology | Format: URL
Complex, interactive ecological constraints regulate species distributions, and understanding these factors is crucial for predicting species persistence. We used occupancy analysis, which corrects for imperfect detection, to test the importance of abiotic and biotic habitat and landscape factors on probability of occupancy by boreal chorus frog (Pseudacris maculata; Agassiz 1850) tadpoles. We hypothesized that hydropattern and predators are primarily important as they affect desiccation and predation risk and can interact in ways difficult to predict. We surveyed 62 wetland sites across an elevational gradient in Colorado, USA and modeled patterns in P. maculata occupancy. Tadpoles were most frequently present in intermediate hydropattern systems with lower desiccation risk and no predatory fish due to occasional drying. P. maculata occupancy had a strong negative relationship with fish presence while tadpoles, odonate larvae and tiger salamanders (Ambystoma mavortium; Baird 1850) frequently co-occurred. Dry seasonal conditions will likely result in fewer intermediate hydropattern ponds available for amphibian breeding. We hypothesize that this will force P. maculata to breed in habitats with fish. As habitats shrink, predators that co-occur with P. maculata are expected to concentrate in the remaining habitat and increase predation risk for developing tadpoles (assuming predators are similarly constricted in their habitat use as amphibians are).