Interview: Deadly Chytid Fungus

Smooth newt (Lissotriton vulgaris) photo by Teresa Dunbar

Interview conducted by Emma Lawlor.

Earlier this month, research was published regarding the status of chytrid fungus in Ireland (read about it here; research that had not been carried out previously, despite the presence of this deadly fungus in the UK. the Herpetological Society of Ireland organised the first Irish Amphibian Chytrid Survey in 2012, carried out by volunteers across the country.

I chatted to one of the authors who lead the research (and the HSI’s senior science officer), Rob Gandola.
What are amphibians?
“A 3oo million year old lineage of well known vertebrates, classified into 3 major groups; the Anura, frogs and toads; Caudata, the newts and salamanders and the Gymnophiona, the caecilians, a group of burrowing amphibians that are superficially similar in appearance to snakes.”
How many amphibians are in Ireland?
“We have three species of amphibians native to Ireland; the Common frog, Rana temporaria; the Smooth newt, Lissotriton vulgaris, and the Natterjack toad, Epidalea (Bufo) calamita. Both the Smooth Newt and the Common Frog have island wide distributions whereas the Natterjack toad only occurs in the Kerry, with an introduced population in Wexford.”
Why is Ireland so important for amphibians?
“Ireland per se is not important for amphibians, particularly in relation to the number of species, however Irish amphibians are important, particularly from a conservation stand point, as both the Common frog and the Natterjack Toad have been shown to possess unique genetic haplotypes that are only found in Ireland. Ireland is also the most westerly boundary of these species’ distributions and therefore their natural history is of scientific importance.”
What gave you the idea to set up the Irish Amphibian Survey?
“Ireland was assumed to be “chytrid free” but no scientific investigations had ever been conducted to
confirm whether this was true or not. So, with this in mind we thought that it would be beneficial to organise an island wide survey of amphibian populations to test for the presence of the fungus. And this was the beginning of the Irish Amphibian Chytrid Survey.”
What is the chytrid fungus and what does it do to amphibians?
“Batrachochytrium dendrobatidis or chytrid for short, is a species of pathogenic fungus that specifically attacks amphibians. The fungus is the cause of ‘chytridiomycosis’. It has the potential to decimate amphibian populations and is known to have single handedly caused the extinction of numerous species of amphibians, mainly in the tropics.”
What’s next for Irish amphibians?
“The establishment of a national amphibian disease monitoring unit to whom any suspected amphibian dies off’s and noticeable declines in local populations could be reported. The unit would also be responsible for monitoring Irish amphibian populations through coordinated island wide disease screening surveys.”

Collie Ennis volunteered to partake in the survey in the Dublin area.
How many times did you go out?
“5 or 6 times throughout March to June during the daytime, while the sun was out and hot!”
Would this have made it more difficult to find them?
“They stay closer to the water at this time. The chytrid fungus may be harder to detect in those in terrestrial habitats, so we wanted to get samples from those nearer the water.”
What did you have to do with the amphibians when you found them?
“We were only to catch adults. While wearing disposable gloves, we swabbed their skin in three areas; the thigh, the lower belly, and the webbing inbetween the hind toes (in the case of frogs) or the tail (in the case of newts). Where possible, we took notes of each individual’s size and sex.”

“It’s great to hear that Ireland is, at present, chytrid-free” said Karl Hamilton, a volunteer, who had helped out with the nation-wide survey.

“My sampling sites were 3 areas of upland heath and grazing land in south Co. Derry, and all had good healthy populations of frogs. It was great to be a part of the Ireland-wide survey to put all our fears at rest (for now)….and it sets the pace for future surveys so we can continue to monitor the health of our native amphibian populations.”


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