Amphibian decline and extinction: What we know and what we need to learn

Collins, James P.

doi:10.3354/dao02307

Cited by 196 publications

(140 citation statements)

References 63 publications

Supporting

Mentioning

134

Contrasting

Unclassified

Order By: Relevance

“…Possible causes of the decline have been investigated; including the possibility of infectious diseases, habitat destruction by land use changes, global climatic changes causing increases in temperature and UV-B radiation, exposure to contaminants including pesticides, and other causes. [1][2][3] No single factor can be attributed to explain the decline, and it is likely that complex interactions between these factors account for the phenomenon. Among these possible causes, the exposure of amphibians to pesticides and industrial chemicals has been targeted, since some chemicals may alter either their normal development by toxic effects, interactions with the thyroid axis and interference with retinoid signaling pathways, or endocrine disruption causing sexual differentiation.…”

Section: Introductionmentioning

confidence: 99%

Bioconcentration and metabolism of pesticides and industrial chemicals in the frog

Katagi

Ose

2014

J. Pestic. Sci.

View full text Add to dashboard Cite

Exposure to pesticide residues is claimed to be one of the possible causes of frog decline. Knowledge of basic information on the uptake, metabolism and depuration processes of pesticides in the frog is needed to understand the relationship between exposure and toxic effects from their actual body burden, together with their bioconcentration. The hydrophobicity of pesticides and industrial chemicals was one of the most important factors controlling bioconcentration, similarly to fish, when frogs are exposed to contaminated water. Skin absorption was also a key route in the uptake process especially in the adult frog. The metabolic profiles in the frog, mainly examined by an intraperitoneal injection technique, were common to other aquatic species without any frog-specific transformation reaction. The effects of developmental stage, sex, species and environmental factors such as temperature were observed for bioconcentration and metabolism.

show abstract

Section: Introductionmentioning

confidence: 99%

Bioconcentration and metabolism of pesticides and industrial chemicals in the frog

Katagi

Ose

2014

J. Pestic. Sci.

View full text Add to dashboard Cite

show abstract

“…One of the main reasons for the decrease in amphibian specimens in natural habitats is chemical pollution (Collins, 2010). The rapid worldwide increase in the use of electrical and electronic equipment, the disposal of which pollutes the environment, has generated the socalled E-waste (Eriksson et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Histopathological and biochemical changes in the liver, kidney, and bloodof amphibians intoxicated with cadmium

Medina¹,

González²,

Klyver³

et al. 2016

Turk J Biol

View full text Add to dashboard Cite

The worldwide decline in amphibian populations has made heavy metal pollution a subject of interest. The aim of this work was to analyze the effect of sublethal doses of cadmium (Cd) on the liver, kidney, and blood of Rhinella arenarum specimens. Serum markers indicative of hepatic injury (gamma glutamyltransferase, alkaline phosphatase, pseudo cholinesterase, and total cholesterol) and markers of renal dysfunction (blood urea nitrogen, serum creatinine, calcium, and glucose) showed variation in animals treated with a 0.5 mg/kg dose compared to controls. Histopathological images revealed alterations in the liver (hepatocyte ballooning and hyperplasia of Kupffer cells) and kidney (renal tubular lumen dilation with tubular necrosis) of animals with abnormal serum markers. The above-mentioned lesions were more evident with the 5 mg/kg dose. With the 0.5 mg/kg dose, hematological values remained normal with the exception of the leukocyte formula. Animals treated with 5 mg/kg showed a significant decrease in both white and red blood cell counts and hematocrit and hemoglobin values. Differential leukocyte counts showed neutrophilia, monocytosis, and lymphopenia. Morphological aberrations were found in white and red blood cells. Results indicated that the evaluation of morphological and functional parameters in kidney, liver, and blood is required in order to monitor amphibian populations exposed to chemical contaminants.

show abstract

“…Given that land use change resulting in habitat des truction is the leading cause of amphibian decline (Collins and Crump 2009;Collins 2010), it seems plausible that habitat loss is a prime driver of the decline in the Boreal Chorus Frog. The fact that unoccupied sites in eastern Ottawa had significantly lower wetland cover values at all spatial scales compared with occupied sites in western Ottawa (Table 2) suggests that landscape differences could explain the apparent decline; however, we have no direct evidence that wetland cover in eastern Ottawa has been reduced since the 1950s.…”

Section: Discussionmentioning

confidence: 99%

“…A global assessment of all known amphibian species revealed that a third were threatened with extinction (Stuart et al 2004). Although multiple causes have been identified, land use change resulting in habitat destruction is the leading cause of amphibian decline and extinction (Collins and Crump 2009;Collins 2010). Amphibian populations have also declined within protected areas where habitat destruction is not a threat.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Apparent widespread decline of the Boreal Chorus Frog (<em>Pseudacris maculata</em>) in eastern Ottawa

Seburn

Gunson²,

Schueler³

2014

Can Field Nat

View full text Add to dashboard Cite

The Boreal Chorus Frog (Pseudacris maculata) was once common in the eastern Ottawa area. To assess its current status, we conducted auditory surveys at 184 wetlands in 2011 and 2012. Boreal Chorus Frogs were heard at only five (2.7%) of the surveyed sites. These five sites were spatially aggregated, with only 0.5-7.5 km between any two sites. Sites occupied by Boreal Chorus Frogs in eastern Ottawa were surrounded by significantly greater agricultural cover (at 1.0-, 1.5-, and 2.0-km radii), less forest cover (1.0-and 2.0-km radii), and less wetland cover (1.5-and 2.0-km radii) than occupied sites in western Ottawa. Sites in eastern Ottawa that were apparently unoccupied were surrounded by significantly greater agricultural cover (only at the 2.0-km radius), similar forest cover (all radii), and less wetland cover (all radii) compared with occupied sites in western Ottawa. Boreal Chorus Frog populations are commonly subject to extirpation resulting from stochastic events. The reduced wetland cover in eastern Ottawa may be accompanied by reduced wetland connectivity, making recolonization of wetlands difficult or impossible. Our data do not show whether wetland connectivity has been reduced, but future research should address this important topic.

show abstract

Amphibian decline and extinction: What we know and what we need to learn

Abstract: For over 350 million yr, thousands of amphibian species have lived on Earth. Since the 1980s, amphibians have been disappearing at an alarming rate, in many cases quite suddenly.

Cited by 196 publications

References 63 publications

Bioconcentration and metabolism of pesticides and industrial chemicals in the frog

Bioconcentration and metabolism of pesticides and industrial chemicals in the frog

Histopathological and biochemical changes in the liver, kidney, and bloodof amphibians intoxicated with cadmium

Apparent widespread decline of the Boreal Chorus Frog (<em>Pseudacris maculata</em>) in eastern Ottawa

Contact Info

Product

Resources

About