Herald SunMany scientists consider frogs the “canaries in the coalmine” of global warming – and frog species have started to disappear.
Frogs are at risk of extinction – not all of them, but enough to catastrophically change ecosystems.
The devastating chytrid fungus, climate change, habitat loss, chemical pollution, over-harvesting, parasites and predatory introduced species — like trout that eat tadpoles — are all contributing to alarming frog loss.
Over the past 30 years, says Dr Graeme Gillespie, director of wildlife, conservation and science at Zoos Victoria, there has been a major decline in frog populations around the world. A number of species have vanished. Australia has 219 species of frog and since the 1970s, close to a dozen species have disappeared. Further, a large proportion — 28 per cent — of frog species are now threatened with extinction — some critically.
“It is a crisis. The International Union for Nature Conservation has recognised the decline of amphibians as the most serious biodiversity loss occurring at the moment,” says Dr Gillespie.
“There has been an accelerated decline from the fungus which we believe has done damage in Australia, and we don’t know how this disease will react to climate change, but habitat loss is the biggest threat to amphibians in the long run.”
Did one of those extinct species, or one close to extinction, hold the cure for cancer? It’s not a silly question. Frogs make a vital contribution to the ecosystem — as middle-order consumers they eat insects, performing an important regulatory role for agriculture, and are themselves eaten by other animals, providing a key link in the food chain — but also, potentially, to human medicine with their extraordinarily protein-rich skin.
Scientists are researching frog toxins for use in sunblocks, antibiotics, skin and colon cancer treatments, medication for depression, bacterial and viral infections, stroke, heart ailments and Alzheimer’s, and in painkillers. The phantasmal poison dart frog from Ecuador secretes a toxin that has been found to be two hundred times more powerful than the painkiller morphine, yet not addictive.
“There is research into frogs for all sorts of applications but the loss of a frog species could also mean the cost of a food crop doubling,” says Dr Gillespie.
“There is this domino effect. If frogs aren’t there to eat the insects there will be an imbalance. And animals that are dependent upon frogs as a food source will disappear. This is happening in Central America now,” says Dr Gillespie.
It is vital that we keep the world’s frogs alive, kicking and croaking through human initiatives — big and small — but according to Dr Gillespie very little is being done to preserve frog species in Australia or abroad.
“The Baw Baw Frog on Victoria’s Mt Baw Baw is close to extinction. There are only a few hundred left, yet this species remains threatened by timber harvesting and forest fires.
“The Spotted Tree Frog lives in mountain streams. Their numbers are declining primarily because of introduced trout, which eat their tadpoles. The fishing lobby is powerful. Other species are also affected by Alpine development. Protecting frogs takes money and political will.
“All these species have a role, and without them, at some point ecosystems collapse like a house of cards.
“We need to reduce our carbon footprint, to consume less energy, stop polluting, start recycling, it all adds up to a healthier environment which ultimately helps frogs — and they need a lot of help.
“People need to get involved in their environment at the local community level. Get involved with managing the local creek. Don’t tip chemicals down the sink, don’t wash your car with chemicals, they all end up in the local waterways and kill frogs.
“If you go to Bali or elsewhere in Asia on holiday, don’t order the frogs legs on the menu for dinner. The frog will have been caught in the wild, depleting local frog populations.”
Next year is the Year of the Frog and Dr Gillespie says the World Zoos and Aquariums Association will tackle this massive conservation problem through the event’s campaign.