Introduction

Amphibian Declines

       At the First World Congress of Herpetology in 1989, participants presented scientific papers and exchanged personal accounts of amphibian declines and disappearances.  Based on the magnitude and geographic extent of documented declines and local extinctions of amphibian populations, the herpetologists concluded that amphibian declines represented a potential global environmental crisis.  Research conducted by many scientists since the meeting has shown a variety of factors have contributed to the global amphibian decline, including acid precipitation, environmental contaminants, introduction of nonindigenous predators, disease agents, parasites, ultraviolet radiation, and unsustainable harvest and trade of amphibians.  Habitat loss has been and continues to be a major factor contributing to declines and extinctions.

       In the United States, amphibian declines of unknown origin were first reported on Puerto Rico and in the western states, where many populations tend to be small and isolated. In addition, malformed amphibians were observed in high numbers in the upper Midwest, Great Lakes region, and northern New England.  Declines in the southeastern U.S. have been linked directly to habitat loss.  Although all regions of the U.S. are not affected to the same degree, the scope of declines and malformations suggests vigilance is needed throughout the Nation to ensure the conservation of amphibian populations.

USGS Amphibian Research and Monitoring Initiative (ARMI)

       In 1998 an international meeting of herpetologists convened by the National Science Foundation concluded that significant amphibian declines have occurred in protected areas not subjected to obvious changes in habitat, such as National Parks, National Wildlife Refuges, and wilderness areas.  In 2000, the President of the United States and the Congress directed the Department of the Interior (DOI) agencies to develop a plan to initiate monitoring of trends in amphibian populations on DOI lands and conduct research into causes of declines. The DOI has stewardship responsibilities over vast land holdings in the US, much of which is occupied by or is potential habitat for amphibians.  The U.S. Geological Survey (USGS), the science and research bureau for DOI, was given lead responsibility for planning and organizing this program, named the Amphibian Research and Monitoring Initiative (ARMI), in cooperation with the National Park Service, US Fish and Wildlife Service (USFWS), and Bureau of Land Management.  USGS is uniquely qualified to develop and provide scientific leadership for such an effort.  It has a long history of employing research scientists who have pioneered studies on amphibian life history, sampling techniques, toxicology, and health-related issues, and it has responsibility for many natural resource monitoring programs at regional, national, and continental scales.

ARMI Objectives

• Establish a network designed to monitor the status and changes in the distributions and abundance of amphibian species and communities in the United States.
   
• Identify and monitor environmental conditions known to affect amphibians and document their differences across the Nation.
   
• Conduct research that identifies causes of amphibian population change and malformations.
   
• Provide information to managers, policy makers and the general public in support of amphibian conservation.

ARMI Framework

       Studies by USGS scientists will concentrate on DOI and other federal lands, but ARMI will provide the framework for incorporating data collected on non-federal lands to encourage participation by states, universities, and non-governmental organizations. The framework can be conceptualized as a pyramid, with extensive and necessarily coarse measurements at many monitoring sites across the country (the base of the pyramid), mid-level efforts at a moderate number of sites to provide a regional perspective on the status of amphibians (the middle portions of the pyramid), and intensive research efforts at a relatively small number of index sites throughout the country (the top of the pyramid). Activities at the different levels of the framework are integrated by:

• Research on causes of change, which at all levels is guided by monitoring results
• Synthesis across ecological regions, scientific disciplines, and governmental and institutional boundaries
• Comparable protocols, analytical tools, training, and planning
• Common databases and reporting
• Ecological modeling

       Monitoring efforts, the primary focus of ARMI, are conducted at all levels of the pyramid, but there is an emphasis at the middle level.  Monitoring conducted at this level of the pyramid is carried out at mid-level monitoring areas, such as National Wildlife Refuges.  Monitoring studies are designed to detect change in occurrence and abundance of species across the mid-level monitoring areas.  There is an emphasis on estimating well-defined parameters using statistical approaches that are applicable across species, monitoring areas, and ARMI regions. One such approach is to use detection/non-detection data to estimate a population level parameter, proportion of area occupied (PAO), on a species by species basis, as well as a community level parameter, species richness.

The Southeast ARMI (SEARMI) Program

       For the purposes of the ARMI program implementation, the United States is divided into seven blocks of States that are the focus of regional herpetological investigations. The Southeast Region encompasses the states of Florida, Georgia, Alabama, Tennessee, South Carolina, and North Carolina, as well as Puerto Rico and the U.S. Virgin Islands, an area approximately 1300 x 1660 kilometers (800 x 1000 linear miles), excluding the Caribbean territories.  Within this area, DOI land holdings are numerous, ranging in size from "postage stamp" historical sites to extremely large ecosystem-wide parks and preserves. Most lands are administered by the National Park Service and the U.S. Fish and Wildlife Service; the Bureau of Land Management has certain responsibilities for oversight in coal mining areas (such as in northern Alabama), but there are no land holdings.  SEARMI research and monitoring efforts are conducted from the Center for Aquatic Resource Studies of the Florida Integrated Science Center, Gainesville, Florida. Additional ARMI related research has been conducted by USGS biologists with the Miami-based Center for Water and Restoration Studies, although they have not received ARMI funding.

       The southeastern U.S. far exceeds any other region of the Nation in the diversity and abundance of amphibians. With at least 144 species of amphibians, it has well over half of all the species known from the U.S.  Habitat diversity is likewise great, ranging from the high mountain peaks of the Great Smoky Mountains, to the humid forested lowlands of the coastal plain, and to the vast marshes of South Florida.  Southeastern amphibians have diverse life histories, from aquatic salamanders that never leave the water and a great variety of salamanders and frogs that spend portions of their life cycle in both aquatic and terrestrial environments, to terrestrial salamanders that never enter the water. Some species are widespread and abundant, whereas others are rare, localized, and highly vulnerable to extirpation.

       As in other regions, SEARMI monitors amphibians based on a three-tiered approach involving sites with intensive research (apex sites), sites that form the basic areas for the core of monitoring activities (mid-level sites), and sites where inventories are conducted (base sites). With few exceptions, federal lands in the southeast have not been surveyed for amphibians or their habitats, thus requiring inventories before proceeding to more intensive study. For this reason, most current research focuses on mid-level and base sites. Another emphasis has been on the development of appropriate sampling techniques and in understanding the biases associated with their use. Information from SEARMI's inventory and monitoring program (data collected from the mid-level and apex sampling sites) will be used to assess the status of amphibians on DOI lands using PAO analyses. By making probabilistic arguments, PAO uses an estimation of site occupancy rate to measure species detection probabilities. More information on PAO appears in the scientific literature. SEARMI biologists are collecting extensive data on species and their habitats that will allow for an assessment of distribution patterns and trends, and the initiation of research on declines or problem areas should they be identified. Finally, we are developing partnerships and collecting data on amphibian distribution, available literature, and the extent of previous amphibian surveys on DOI lands.

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