TY - JOUR
T1 - After the epidemic
T2 - Ongoing declines, stabilizations and recoveries in amphibians afflicted by chytridiomycosis
AU - Scheele, Ben C.
AU - Skerratt, Lee F.
AU - Grogan, Laura F.
AU - Hunter, David A.
AU - Clemann, Nick
AU - McFadden, Michael
AU - Newell, David
AU - Hoskin, Conrad J.
AU - Gillespie, Graeme R.
AU - Heard, Geoffrey W.
AU - Brannelly, Laura
AU - Roberts, Alexandra A.
AU - Berger, Lee
N1 - Includes bibliographical references.
PY - 2017/2/1
Y1 - 2017/2/1
N2 - The impacts of pathogen emergence in na�ve hosts can be catastrophic, and pathogen spread now ranks as a major threat to biodiversity. However, pathogen impacts can persist for decades after epidemics and produce variable host outcomes. Chytridiomycosis in amphibians (caused by the fungal pathogen Batrachochytrium dendrobatidis, Bd) is an exemplar, with impacts ranging from rapid population crashes and extinctions, to population declines and subsequent recoveries. Here, we investigate long-term impacts associated with chytridiomycosis in Australia. We conducted a continent-wide assessment of the disease, reviewing data collected since the arrival of Bd in about 1978, to assess and characterize mechanisms driving past, present and future impacts. We found chytridiomycosis to be implicated in the extinction or decline of 43 of Australia's 238 amphibian species. Population trajectories of declined species are highly variable; six species are experiencing ongoing declines, eight species are apparently stable and 11 species are recovering. Our results highlight that while some species are expanding, Bd continues to threaten species long after its emergence. Australian case-studies and synthesis of the global chytridiomycosis literature suggests that amphibian reservoir hosts are associated with continued declines in endemically infected populations, while population stability is promoted by environmental conditions that restrict Bd impact, and maintenance of high recruitment capacity that can offset mortality. Host genetic adaptation or decreased pathogen virulence may facilitate species recovery, but neither has been empirically demonstrated. Understanding processes that influence Bd-host dynamics and population persistence is crucial for assessing species extinction risk and identifying strategies to conserve disease-threatened species.
AB - The impacts of pathogen emergence in na�ve hosts can be catastrophic, and pathogen spread now ranks as a major threat to biodiversity. However, pathogen impacts can persist for decades after epidemics and produce variable host outcomes. Chytridiomycosis in amphibians (caused by the fungal pathogen Batrachochytrium dendrobatidis, Bd) is an exemplar, with impacts ranging from rapid population crashes and extinctions, to population declines and subsequent recoveries. Here, we investigate long-term impacts associated with chytridiomycosis in Australia. We conducted a continent-wide assessment of the disease, reviewing data collected since the arrival of Bd in about 1978, to assess and characterize mechanisms driving past, present and future impacts. We found chytridiomycosis to be implicated in the extinction or decline of 43 of Australia's 238 amphibian species. Population trajectories of declined species are highly variable; six species are experiencing ongoing declines, eight species are apparently stable and 11 species are recovering. Our results highlight that while some species are expanding, Bd continues to threaten species long after its emergence. Australian case-studies and synthesis of the global chytridiomycosis literature suggests that amphibian reservoir hosts are associated with continued declines in endemically infected populations, while population stability is promoted by environmental conditions that restrict Bd impact, and maintenance of high recruitment capacity that can offset mortality. Host genetic adaptation or decreased pathogen virulence may facilitate species recovery, but neither has been empirically demonstrated. Understanding processes that influence Bd-host dynamics and population persistence is crucial for assessing species extinction risk and identifying strategies to conserve disease-threatened species.
KW - Amphibian
KW - Chytrid fungus
KW - Extinction
KW - Recovery
KW - Wildlife disease
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U2 - 10.1016/j.biocon.2016.12.010
DO - 10.1016/j.biocon.2016.12.010
M3 - Review article
AN - SCOPUS:85007247093
VL - 206
SP - 37
EP - 46
JO - Biological Conservation
JF - Biological Conservation
SN - 0006-3207
ER -