by heather paulheather paul by leein hisroomleein hisroomby renato gaigarenato gaiga by brian...

By Heather Paul

By Leein HisroomBy Renato Gaiga

By Brian Gratwicke

By Brian Gratwick

By Andreas Kay

The frog-killing fungus in

Nanaimo, BCAn undergraduate research project by Patrick

Reid

Part 1 WORLDWIDEPart 2 The local AREA

Part 3 Implications

The frog-killing fungus

PART 1 WORLDWIDE

By Geoff Gallice

AMPHIBIAN STATUS Recent worldwide declines 1/3 of all identified species are

at risk of extinction

(Stuart et al. 2004)

Amphibians are the most threatened vertebrate group.

SAD FROG

By Elvir B

Amphibian

Declines

Habitat Loss

Over Exploitatio

n

Invasive Species Pollution

Wildlife Diseases

Climate Change

Declines in pristine mountain areas.

How is this possible?

Chytrid Fungus (Batrachochytrium dendrobatidis)

Potentially lethal skin infection on amphibians (Berger

et al. 1998)

Caused decline or extinction of 200 amphibian species worldwide (Skerrat et al. 2007)

Amphibia.web

The emergence of Bd may represent the greatest pathogen-associated biodiversity loss in recorded history (Skerrat et al. 2007)

Why the recent increase

in Bd-associated mortalities?

BatrcachochytriumdendrobatidisBatrachochytrium

dendrobatidis

Strain level(variants)

Species level

KIll (no/yes)

Multiple variants: some kill some don't(Berger et al. 2005)

Spread of Bd

Past

Present

Global Spread of pathogenic variants of Bd

(Example: not actual locations)

Strain A

Strain BStrain C

Pathogenic strains may have been spread through the amphibian trade

American bullfrogs are resistant to Bd and me be acting as global carriers (Daszak et

al. 2004; Schloegel et al. 2012)

Bullfrogs as disease carriers

By Goly Shev

By Jonathan E. Kolby

Amphibians for worldwide shipment Bullfrogs being sold in Shanghai

Part 2 The local AREA

By Ken Walker

Local species infected with BD

American bullfrog(Lithobates

catesbeianus)

Western Toad (Anaxyrus boreas)

Photo courtesy of Bill Pennell Photo courtesy of Elke Wind

Western toads Blue-listed in BC (at risk of becoming

threatened) Bd-caused declines of Western Toads

in the United States raises concern (Muths et al. 2003)

Photo courtesy of Elke Wind

American bullfrogs Invasive species on Vancouver Island

May have brought foreign strains to local area

May spread infections among local toads

research objective

Use strain data to asses

bullfrogs role in the local spread and arrival of Bd

Find out what strain (variant) is present on local

toads and bullfrogs

Swabbing for presence of Bd

Analysis of Skin Swabs

Extract

Detect

Identify Strain

Part 3 Implications

The strain detected (CW 34) is likely pathogenic to amphibians, heightening the risk for toad mortalities locally.

How did it get to Nanaimo?

bullfrogs Role in the spread of Bd

Possibility

Evidence

resultArrived to

Nanaimo on bullfrogs

Transferred between bullfrogs and toads

CW 34 on bullfrogs in the amphibian trade

and locally

CW 34 present on both bullfrogs and toads in Nanaimo

Does not refute

Support

Take home messages Amphibians are declining, with Bd

acting as a strong contributor Toads and bullfrogs in the local area

are infected with the Bd The presence of a pathogenic strain

of Bd on local toads heightens the importance of monitoring toad populations

By Heather Paul

By Leein HisroomBy Renato Gaiga

By Brian Gratwicke

By Brian Gratwick

By Andreas KayBy Heather Paul

By Leein HisroomBy Renato Gaiga

By Brian Gratwicke

Acknowledgment

I would like to thank Hitomi Kimura for helping me with the research and my supervisors Dr. Eric Demers for guiding me through the project and

Dr. Catherine Thomson for her molecular knowledge. I am grateful

for the help of Wendy Simms and Dr. Timothy Goater in collecting bullfrog

samples.samples.

ReferencesBerger, L., G. Marantelli, L.F. Skerratt and R. Speare. 2005b. Virulence of the amphibian chytrid

fungus Batrachochytrium dendrobatidis varies with the strain. Disease of Aquatic Organisms 68:47-50.

Berger, L., R. Speare, P. Daszak, D.E. Green, A.A. Cunningham, C.L. Goggin, R. Slocombeh, M.A. Ragani, A.D. Hyatt, K.R. MCDonald, H.B. Hinesk, K.R. Lips, G. Marantellim and H. Paresb. 1998. Chytridiomycosis causes amphibian mortality associated with population declines in the rain forests of Australia and Central America. Proceedings of the National Academy of Sciences USA 95:9031-9036.

Daszak, P., A. Strieby, A.A. Cunningham, J.E. Longcore, C.C. Brown and D. Porter. 2004 Experimental evidence that the bullfrog (Rana catesbeiana) is a potential carrier of chytridiomycosis, an emerging fungal disease of amphibians. Herpetol. J. 14:201-207.

Muths, E, P.S. Corn, A.P. Pessier, and D.E Green. 2003. Evidence for disease-related amphibian decline in Colorado. Biological Conservation 110:357-365.

Schloegel, L.M., L.F. Toledo, J.E. Longcore, S.E. Greenspan, C.A. Vieira, M. Lee, S. Zhao, C. Wangen, C.M. Ferreira, M.R. Hipolito, A.J. Davies, C.A. Cuomo, P. Daszak and T.Y. James. 2012. Novel, panzootic and hybrid genotypes of amphibian chytridiomycosis associated with the bullfrog trade. Molecular Ecology 21:5162–5177.

Skerratt, L.F., L. Berger, R. Speare, S. Cashins, K.R. McDonald, A.D. Phillott, H.B. Hines and N. Kenyon. 2007. Spread of chytridiomycosis has caused the rapid global decline and extinction of frogs. EcoHealth 4 :125-134.

Stuart, S.N., M. Hoffmann, J.S. Chanson, N.A. Cox, R.J. Berridge, P. Ramani and B.E. Young. 2008. Threatened Amphibians of the World. Lynx Edicions, Barcelona, Spain.