Geological Survey-led research suggests that even though amphibians are severely declining worldwide, there is no smoking gun — and thus no simple solution — to halting or reversing these declines.
The areas of the United States that are most at risk of a potentially invasive salamander fungus are the Pacific coast, the southern Appalachian Mountains and the mid-Atlantic regions, according to a recently published U. Geological Survey report. A deadly fungus causing population crashes in wild European salamanders could emerge in the United States and threaten already declining amphibians here, according to a report released today by the U.
The first-ever estimate of how fast frogs, toads and salamanders in the United States are disappearing from their habitats reveals they are vanishing at an alarming and rapid rate. The breakdown products oxons of the three most commonly used organophosphorus pesticides in California's agricultural Central Valley -- chlorpyrifos, malathion and diazinon -- are 10 - times more toxic to amphibians than their parent compounds, which are already highly toxic to amphibians, according to experiments conducted by scientists of Southern Illinois University, Carbondale.
New USGS research shows that rural areas and farms may be friendlier to frogs and toads than urban areas. Melinda Knutson, a conservation scientist with the U. Geological Survey, said the research on frog and toad populations in two Midwestern states shows that frog and toad abundance and species richness were low in urban areas but near normal in agricultural areas. An American bullfrom is native to most eastern states, but considered invasive in the moutain west.
Skip to main content. Search Search. Biology and Ecosystems. They include: Human influence from the Mississippi River east, including the metropolitan areas of the Northeast and the agricultural-dominated landscapes of the Midwest Disease, particularly a chytrid fungus in the Upper Midwest and New England Pesticide applications east of the Colorado River Climate changes across the Southern U.
Apply Filter. What is the United States doing about amphibian deformity and decline issues? In response to indications of worldwide declines in amphibian populations, Interior Department agencies were directed to initiate a national program of amphibian monitoring, research, and conservation.
There is an urgent need to determine the scope and severity of the problem and to investigate causes. What causes deformities in frogs, toads, and other amphibians? Malformed frogs first came to national attention in Since that time, reports of malformed frogs and other amphibians have increased dramatically.
Malformations have been reported in at least 44 states and in more than 50 species of frogs and toads. Multiple limbs, missing limbs, and facial abnormalities are the main malformations seen. How many amphibian species are there in the United States? More than 6, amphibian species exist worldwide, with approximately of them found in the United States. The USGS is the lead agency for the Amphibian Research and Monitoring Initiative ARMI , a program of amphibian monitoring, research, and conservation that was established in response to the worldwide decline of amphibian species.
Filter Total Items: 6. Year Published: Early action to address an emerging wildlife disease A deadly fungal pathogen, Batrachochytrium salamandrivorans Bsal that affects amphibian skin was discovered during a die-off of European fire salamanders Salamandra salamandra in Adams, M.
Camille; Grear, Daniel A. View Citation. Geological Survey Fact Sheet , 2 p. Year Published: Mapping habitat for multiple species in the Desert Southwest Many utility scale renewable energy projects are currently proposed across the Mojave Ecoregion. Inman, Richard D. Year Published: Species data: National inventory of range maps and distribution models The Gap Analysis Project GAP produces data and tools that help meet critical national challenges such as biodiversity conservation, renewable energy development, climate change adaptation, and infrastructure investment.
Gergely, Kevin J. Measure content performance. Develop and improve products. List of Partners vendors. Share Flipboard Email. Bob Strauss. Science Writer. Updated March 25, Featured Video.
Cite this Article Format. Strauss, Bob. Why Are Amphibians in Decline? All About the Axolotl Ambystoma mexicanum. Your Privacy Rights. Richness map of Threatened amphibian species, with dark red colours corresponding to higher number of species. Table 1. A comparison of Threatened categories for Amphibians, Birds and Mammals.
Threatened with extinction. Critically Endangered or Endangered. Data Deficient. Based on data from Baillie et al. Actual number of species in each category is in parentheses. They are:. Each of the threats is briefly outlined below. Figure 3. Data were not available for determining how many amphibian species are threatened by Global climate change including UV.
Many amphibians require specific microhabitats with appropriate conditions of moisture, temperature, pH and sufficient refuges and food resources. These conditions are easily disrupted during even minor habitat modifications. The most common forms of habitat change are clearance for crops, logging, clear-cutting, urbanization and industrial development.
The extent of the effects of habitat change can be difficult to determine as many amphibians spend most of their lives in one or two terrestrial environments and seasonally migrate to a different, usually aquatic environment, to breed.
To disrupt the breeding migration would thereby cause a decline see Becker et al. Habitat change may affect one or more of the habitats necessary for completion of the life cycle, for example, the environment in which the amphibians spend most of their year e.
Most amphibians do not live in isolation in a single microhabitat and effective conservation will require an integrated landscape approach as outlined by Lindenmayer et al. In addition, since the beginning of the 20 th century human populations have grown exponentially, with concomitant habitat alteration and destruction, and most of this change has occurred in tropical and subtropical ecoregions of high amphibian diversity and endemism Gallant et al.
To a lesser extent some invasive species may actually hybridise with the native species, disrupting genetic integrity e. The list of particularly damaging invasive species includes fish e. A surprisingly huge number of frogs hundreds of millions of individuals, Altherr et al. However, the United States international trade is dominated by commercially bred bullfrogs Lithobates catesbeianus , with the overall trade of this species superseding trade of other highly traded frog species by several orders of magnitude the US alone imported between 2,, tonnes per annum of captive-bred bullfrogs from ; Altherr et al.
Unfortunately, similarly detailed trade and sourcing captive bred, wild information for other major markets is not readily available to determine whether this could be a pattern across importing countries. Although no large-scale declines have been attributed to collection for medicinal purposes, there have been reports of local population declines Ye et al. Many species of amphibians are collected for the pet trade, and in some countries such as Madagascar this represents a considerable financial income Carpenter et al.
Nevertheless, only a small fraction of amphibian species is listed under any of the Appendices, and most of the heavily traded amphibians in the US are not regulated by CITES Schlaepfer et al. Furthermore, taxonomic issues compound this matter further as there are cryptic species that could easily be assigned to a nominal species and go undetected even in countries that do keep such species records.
Therefore, it is very likely that current CITES listings underrepresent the number of amphibian species in international trade. The PWG connected the researchers involved with monitoring amphibian mass mortality incidents and helped arrange a week-long meeting at the University of Illinois for all the scientists concerned. At the meeting it was concluded that the organism implicated with the mass mortalities was the same in Australia and Central America and that it belonged to an ancient group of fungi, the Chytridiales.
This organism belonged to an undescribed genus that had previously not been known to affect vertebrates. Berger et al. Fifteen years later, Bd is still considered to be one of the most severe threats faced by any vertebrate group Fisher et al.
An unprecedented number of fungal diseases has recently been documented to cause severe declines in animals and plants and is beginning to be recognised as one of the most severe risks to biodiversity in general Fisher et al. The biology of Bd is well suited to position this disease as a very serious threat to amphibians. Amphibians have a uniquely permeable skin compared to other vertebrates and most species cannot easily control the movement of water across their external surface, making them particularly sensitive to any changes in water quality.
Lethal, direct, sub-lethal and indirect effects have been reported for many environmental pollutants, such as heavy metals like mercury Bergeron et al. Hayes et al. The subtle and synergistic effects of many of these contaminants can be very difficult to determine. In response to changes in average temperatures and rainfall patterns, amphibians have already been reported to have altered their breeding phenology by shifting the timing of their breeding behaviour Blaustein et al.
This has severe implications for the survival of their larvae due to snowmelt or desiccation. As highlighted in the previous section, amphibians have a sensitive permeable skin and are therefore very susceptible to changes in the amount and timing of rainfall and increasing dry periods. Furthermore, climate change has been documented to cause amphibian populations to expand their range to higher elevations, bringing species and accompanying pathogens into new habitats, with new competitive interactions Raxworthy et al.
In addition, the increase in UV-B caused by the decreasing levels of ozone in the atmosphere has been shown to be particularly damaging to amphibians in general and their eggs Blaustein et al.
However, recent studies imply that UV-B may not be a significant contributor to global amphibian declines Vredenburg et al. Although many of these issues may seem insurmountable, Shoo et al. Hof et al. There has been considerable debate on the synergistic effects of global climate change on disease Pounds et al. Addressing these issues is undoubtedly one of the most challenging conservation problems of our times. One of the earlier problems with identifying amphibian declines was the lack of a consistent monitoring system, and the first output from the DAPTF was the publication of a standard amphibian monitoring handbook Heyer et al.
This led to a network of DAPTF groups monitoring amphibians around the world in an easily comparative way and disseminating their results through the newsletter FrogLog. Furthermore, several texts on amphibian declines were also published e. Green, ; Lannoo, ; ; Linder et al. The overall goal of the Summit was to produce a comprehensive plan to respond to the on-going declines and extinctions of amphibian species by developing targeted actions to counter the different threats identified.
The delegates acknowledged a poor understanding of the complex relationships among all the potential causal factors. A subset of the delegates also wrote white papers for each theme covered that formed the backbone of a comprehensive Amphibian Conservation Action Plan ACAP Gascon et al.
In this form the ACAP could respond to new findings and evolve to keep up to date with current knowledge. As no single answer will prevent further losses of amphibian species, an interdisciplinary approach was used in the ACAP to design a response that was suited to the scale of the problem.
The ACAP outlined priority action steps for amphibian conservation within eleven thematic areas: 1 identifying, prioritising and safe-guarding Key Biodiversity Areas; 2 freshwater resources and associated terrestrial landscapes; 3 climate change, biodiversity loss and amphibian declines; 4 emerging infectious diseases; 5 over-harvesting; 6 mitigating impacts of environmental contamination on amphibian population; 7 captive programmes; 8 reintroductions; 9 the continuing need for assessments: making the GAA an ongoing process; 10 systematics and conservation; 11 bioresource banking efforts in support of amphibian conservation.
The ASG supports development and dissemination of new tools and best practices for adoption and application by a network of local, national, and regional working groups. The ASG has been able to implement a range of conservation initiatives focused around habitat protection in partnership with local and international organisations.
Supporting the creation of 14 new protected areas for amphibians in Latin America, Africa and Asia and the development of new community conservation areas. Protecting over 22, hectares of critical amphibian habitat, home to over 55 threatened or endemic species.
This is shown through a range of programs including:. A partnership in Sulawesi with the Alliance for Tompotika Conservation, where local communities and children have been actively engaged in an educational campaign celebrating biodiversity.
A training course in Haiti run in partnership with Panos Caribbean to teach and train young journalists aged in biodiversity conservation, amphibian protection, and conservation communication. Supporting the creation and implementation of 12 National and Regional Action Plans. Spearheading an initiative — the Search for Lost Frogs — that has supported researchers to undertake expeditions in 21 countries resulting in 15 species rediscoveries to date.
The Search for Lost Frogs generated over news articles in 21 countries, bringing a message about the importance of amphibians to a broad audience. The speed at which some species were disappearing, and the lack of a full understanding on how to abate some of the most acute threats that amphibians face, particularly those affected by Bd, meant that the only way to ensure the survival of some species was by buying time through captive breeding programmes.
AArk analyses suggest that over species require captive breeding assistance, which when extrapolated to all Threatened and Data-Deficient species would result in about species requiring captive populations. Unfortunately, the estimated global capacity for managing viable captive populations at the present time is only about 50 species. The AArk and its partners has also delivered 52 Ex Situ Conservation Training courses in 30 countries, and has trained over 1, students in amphibian biology, husbandry and conservation practices.
The main goal of the campaign was to generate public awareness and understanding of the amphibian extinction crisis and to ensure sustainability of survival assurance populations by creating funding for this conservation work.
While the campaign was successful in raising awareness and funds, one of the drawbacks of such a concentrated and focussed campaign seems to be that once the campaign has finished the general public assumes the problems have been solved. Therefore, Simon Stuart, as new SSC Chair, convened an Amphibian Mini-Summit in in London at which various parties committed to form the Amphibian Survival Alliance to combat amphibian declines and extinctions at a higher level than ever before.
The participants also prioritised attention to two actions in the ACAP: stopping extinctions of species threatened by land use change or commercial use; and stopping the spread and reversing the impact of the amphibian chytrid fungus.
In addition to these two priorities, the ASA also embraced expanding ex situ rescue operations as a priority issue to secure the persistence of amphibian species. However, it now needs to bring more organisations and institutions into the Alliance, and more importantly, become instrumental in making resources and funds available to galvanise amphibian conservation. The ASA was established to provide a powerful driving force to ensure efficient and effective coordination and collaboration between the main themes of amphibian conservation.
The ASA will put in place a global strategy that will implicitly connect with other communities, scientific or otherwise, outside of amphibian specialists. In addition, where necessary e. To support the AWGs and many of the new amphibian conservation initiatives, the ASA is engaging with the business sector and will shortly be releasing an amphibian conservation business plan. However, in spite of some attempts to create awareness, a large audience is still unaware of the amphibian crisis and its implications, and even some large organisations dedicated to biodiversity conservation have not embraced the amphibian cause.
If we keep trying to save amphibians in isolation it will continue to be an uphill struggle, so it is very important to capitalise on the fact that amphibian conservation touches on many aspects of environmental conservation, and therefore provides numerous opportunities to unite efforts across sectors.
By our own count, amphibian conservation can be utilised in 15 of the 20 targets of the revised and updated Strategic Plan for Biodiversity Aichi Biodiversity Targets , that the Convention on Biological Diversity CBD subscribed countries agreed upon CBD, Habitat destruction and degradation has a negative effect on two out of every three amphibian species across the world. It also has a negative effect on many other types of animals and plants, and this immediately provides an opportunity to reach out beyond the amphibian community — a quick look at the sites identified by the Alliance for Zero Extinction highlights that in many cases, sites of conservation importance for amphibians are also important for many other different types of plants and animals.
Organisations that are involved with the conservation of other taxonomic groups with significantly more access to resources, either because of the charismatic species involved or because of the utilitarian nature of the taxonomic group e. Partnerships with such organisations have the potential to scale up habitat protection for amphibians to a truly global scale by integrating amphibians into conservation planning and implementation.
In this regard the ASG has had some success working with bird-oriented conservation organisations in its efforts to set aside habitat that is important for amphibians e. Similar efforts should be explored with other groups that have more resonance with people.
This is something that also requires us to bear in mind the potential effects of climate change and to develop ties with those institutions and organisations working on the topic to ensure that amphibians are also considered in their efforts and benefit from their initiatives. Amphibian distributional data can be used to identify watersheds that are biologically connected, and also to connect the conservation management unit reserves with the water management units river basins.
The water sector is an important constituency with which to build synergies, as water management and provision is one of the key issues that everybody agrees is essential both for a healthy environment and opportunities for development. In addition, it would be important to work with the Conventions to ensure that they emphasise the role of amphibians as indicators of the health of wetlands, much more than they have done until now.
As stated above, their specific biological needs force us to integrate the management of these two realms. It is well documented that pollution in the form of chemical contaminants, including substances that are used in agriculture, is partially responsible for the decline of many amphibian populations Chanson et al. As food production intensifies, not only will the water demand for agriculture rise in many parts of the world, but so will the amount of chemicals used. In addition, water will also be in high demand for energy production, and it will be very important that against these demands we all ensure that the water supply to the environment is sufficient to keep ecosystems functioning and providing vital environmental services.
It is in this regard that amphibians can be used as a general indicator of the state of biodiversity. There are already reports of amphibian declines due to lack of access to water McMenamin et al. Setting monitoring programs that allow us to compare the population and richness trends of amphibians in intact forests with those near commodity production plots could provide an early warning system for the potential effects of such chemical substances on other living beings and to guide policy to regulate these substances.
While the chytridiomycosis epidemic has opened a whole new field of research — the fungus is interesting in itself, being the only known species within a large group of fungi that interacts with animals — it is important to focus the research towards practical recommendations that help to manage the disease Woodhams et al. Prophylactic or remedial treatments of the disease and protocols for reintroduction of captive bred individuals into their natural environment are among the top priorities; there have been several reports of individuals of some species in captivity and in the wild healing or tolerating the infection e.
Bishop et al. This requires a thorough integration of captive breeding efforts with in situ conservation in order to undertake field trials that allow us to explore systematically different ideas to mitigate, if not cure, the disease, and to follow recommendations for reintroduction.
This in turn relies on additional local capacity building so that captive breeding efforts can take place as close as possible to the original ranges of the species being bred. Even here there is room to collaborate with sectors beyond the amphibian community. For example, emerging infectious diseases caused by fungi are now recognised as a threat to food security and, after the emergence of the chytrid fungus on amphibians and the white-nose fungal syndrome in bats, fungal diseases are now seen as a general global threat to animal health and thus have a substantial negative impact on biodiversity Fisher et al.
Chytridiomycosis has been put forward as a model disease to understand the spread and persistence of other fungal pathogens in particular, and of emerging infectious wildlife diseases in general e. Rachowicz et al. We have learned an enormous amount about the disease since then, and major advances in the science particularly following recent field trials, e. Amphibian conservation has been underfunded for many years — this is probably the most conspicuous factor responsible for the limited progress to stop the crisis so far.
We need to keep educating others on the role of amphibians as barometers of ecosystem health, and to insert amphibians as a necessary component of broader environmental issues. And we need to keep binding the amphibian conservation community together to be able to present a united and coherent front to all of these audiences, which may facilitate dialogue and access to resources.
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