Action
Action Synopsis: Amphibian Conservation About Actions
-
Overall effectiveness category Unknown effectiveness (limited evidence)
-
Number of studies: 2
- Share Tweet Icons/envelope Email
View assessment score
Hide assessment score
How is the evidence assessed?
-
Effectiveness
10%
-
Certainty
-
Harms
40%
Calculating overall effectiveness category
Expert assessment panel
Background information and definitions
The movement of field biologists increases the risk of spreading wildlife diseases such as the chytrid fungus Batrachochytrium dendrobatidis. For example, the chytrid fungus has been found to survive in lake water for seven weeks and tap water for three weeks after introduction (Johnson & Speare 2003). Precautions therefore need to be taken to reduce the risk of spreading diseases between sites and populations. This is also the case within and between captive populations.
We found no evidence for the effects of sterilizing equipment when moving between amphibian sites on the spread of disease between amphibian populations. The studies captured here examine the effect of different types of disinfectants on amphibians.
There is additional literature examining the effectiveness of using a range of disinfectants to kill the chytrid fungus Batrachochytrium dendrobatidis. Most chemicals killed 100% of chytrid zoospores when used at certain concentrations (e.g. sodium chloride, household bleach, potassium permanganate, formaldehyde solution, Path-XTM agricultural disinfectant, quaternary ammonium compound 128, Dithane, Virkon, ethanol and benzalkonium chloride; Johnson et al. 2003; Webb et al. 2007). Complete drying of the fungus or heating above 37°C for at least four hours also resulted in 100% mortality (Johnson et al. 2003).
Johnson M.L., Berger L., Philips L. & Speare R. (2003) Fungicidal effects of chemical disinfectants, UV light, desiccation and heat on the amphibian chytrid Batrachochytrium dendrobatidis. Diseases of Aquatic Organisms, 57, 255–260.
Johnson M. & Speare R. (2003) Survival of Batrachochytrium dendrobatidis in water: quarantine and disease control implications. Emerging Infectious Diseases, 9, 922–925.
Webb R., Mendez D., Berger L. & Speare R. (2007) Additional disinfectants effective against the amphibian chytrid fungus Batrachochytrium dendrobatidis. Diseases of Aquatic Organisms, 74, 13–16.
Read more
Read less
Study locations
Key messages
- We found no evidence for the effects of sterilizing equipment when moving between amphibian sites on the spread of disease between amphibian populations or individuals.
- Two randomized, replicated, controlled study in Switzerland and Sweden found that Virkon S disinfectant did not affect survival, mass or behaviour of common frog or common toad tadpoles or moor frog embryos or hatchlings. One of the studies found that bleach significantly reduced survival of common frog and common toad tadpoles.
About key messages
Key messages provide a descriptive index to studies we have found that test this intervention.
Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.
Supporting evidence from individual studies
A randomized, replicated, controlled study in 30 artificial pools in Switzerland (Schmidt et al. 2009) found that Virkon S disinfectant did not affect survival, mass or behaviour of common frog Rana temporaria and common toad Bufo bufo tadpoles, but bleach did. Survival did not differ between Virkon treatments for frogs (untreated: 70–100%; low dose: 90–100%; high dose: 40–100%) or toads (untreated: 90–100%; low dose: 100%; high dose: 70–100%). All tadpoles died within 1–2 days in high dose bleach. Survival was significantly lower in low dose bleach than untreated water for frogs (20–100 vs 70–100%) and toads (40–100 vs 90–100%). Frog tadpole mass was significantly higher in low dose bleach (0.5–0.6 g) than other treatments (0.3–0.5 g). Toad tadpole mass did not differ (0.2–0.4 g). The proportion of tadpoles feeding did not differ significantly for frogs (0.4–0.9) or toads (0.6–0.9). Local leaves, phytoplankton, zooplankton and a snail were added to artificial pools (80 L). Disinfectants (bleach 2%; Virkon 10 g/L) that would be used for boots and field equipment were applied to pools once a week at high (0.04 L) or low doses (0.004 L), with 0.060 L or 0.096 L of water respectively. Water was added as the control. Treatments were replicated five times and assigned randomly to tubs. Ten frog and toad tadpoles were added to each treatment.
Study and other actions testedA randomized, replicated, controlled study in 2011 of captive moor frogs Rana arvalis at Uppsala University, Sweden (Hangartner & Laurila 2012) found that Virkon S disinfectant had no significant effects on moor frog embryos and hatchlings, but did reduce hatching success. Embryonic survival was significantly lower in the low (92%), but not high concentration of Virkon S (94%) compared to the control (99%). Abnormalities were infrequent in all treatments (low: 3%; high: 4%; control: 1%). Hatchling body length did not differ between treatments (5 mm). However, hatching success was lower with Virkon S compared to without, suggesting that it may have weak negative effects on amphibian embryos. Embryos and hatchlings were reared at 19°C in high (5 mg/L) and low (0.5 mg/L) Virkon S concentrations and in a control of water. One embryo and six hatchlings from each of six clutches were used per treatment. Survival was recorded daily until the free swimming stage and hatchling length for seven days.
Study and other actions tested
Please cite as:
Smith, R.K., Meredith, H. & Sutherland, W.J. (2020) Amphibian Conservation. Pages 9-64 in: W.J. Sutherland, L.V. Dicks, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2020. Open Book Publishers,Cambridge, UK.
Where has this evidence come from?
List of journals searched by synopsis
All the journals searched for all synopses
This Action forms part of the Action Synopsis:
Amphibian Conservation
Related Actions
| Actions | Effectiveness | Studies | Category | |
|---|---|---|---|---|
| Immunize amphibians against chytridiomycosis infection Action Link | Unknown effectiveness (limited evidence) | 1 | Synopsis Link | |
| Use antifungal treatment to reduce chytridiomycosis infection Action Link | Trade-off between benefit and harms | 18 | Synopsis Link | |
| Add salt to ponds to reduce chytridiomycosis Action Link | Unknown effectiveness (limited evidence) | 1 | Synopsis Link |
All related actions
Amphibian Conservation - Published 2014
Buy online (Pelagic Publushing)
Download PDF View PDF
Amphibian Synopsis
All synopses About synopses Synopsis protocols Synopsis advisory board
Effectiveness
An assessment by independent experts of the effectiveness of this action based on the summarized evidence (0% = not effective, 100% = highly effective). This score is based on the direction and size of the effects reported in each study. Actions with high scores typically have large, desirable effects on the target species/habitat in each study. There is some variation between actions, e.g. 100% effectiveness in adding underpasses under roads for bat conservation will likely have different impacts to 100% effectiveness in restoring marsh habitat. The effectiveness score does not consider the quantity or quality of studies; a single, poorly designed study could generate a high effectiveness score. The effectiveness score is combined with the certainty and harms scores to determine the overall effectiveness category (for more details see https://www.conservationevidence.com/content/page/79).
Harms
An assessment by independent experts of the harms of this action to the target group of species/habitat, based on the summarized evidence (0% = none, 100% = major undesirable effects). Undesirable effects on other groups of species/habitats are not considered in this score. The harms score is combined with the effectiveness and certainty scores to determine the overall effectiveness category (for more details see https://www.conservationevidence.com/content/page/79).
Certainty
An assessment by independent experts of the certainty of the evidence for this action based on the summarized evidence (0% = no evidence, 100% = high quality evidence). How certain can we be that the effectiveness score applies to all targets of the intervention (e.g. all birds for an action in the bird synopsis)? This score is based on the number, quality and coverage (species, habitats, geographical locations) of studies. Actions with high scores are supported by lots of well-designed studies with a broad coverage relative to the scope of the intervention. However, the definition of "lots" and "well-designed" will vary between interventions and synopses depending on the breadth of the subject. The certainty score is combined with the effectiveness and harms scores to determine the overall effectiveness category (for more details see https://www.conservationevidence.com/content/page/79).
Overall Effectiveness Category
The overall effectiveness category is determined using effectiveness, certainty and harms scores generated by a structured assessment process with multiple rounds of anonymous scoring and commenting (a modified Delphi method). In this assessment, independent subject experts (listed for each synopsis) interpret the summarized evidence using standardised instructions. For more details see https://www.conservationevidence.com/content/page/79.
