These days it's not easy being a frog
Today I'm going to talk about the worldwide
decline of amphibians.
First of all, what are amphibians ?
Amphibians are animals that can live both
on land and in water. Generally they spawn
eggs in water and their larva live in water.
Sometimes adults are terrestrial, but still
they have highly permeable skins so that
they can absorb water through their skin.
For example, frogs, toads, salamanders, and
newts are all amphibians. Due to those features
they are very sensitive to the change in
water and air quality.
The Global Amphibian Assessment is the work
of over 500 scientists from more than 60
countries over a period of 3 years. The study
analyzed the distribution and conservation
status of all 5,743 known amphibian species
and was published in Science Express this
According to the study, 1,856 species which
is almost a third, are now threatened with
extinction. As many as 122 species may have
died out since 1980. 43% of all amphibians
are declining, 27% are stable, less than
1% are increasing, and the status of the
rest is unknown. In some places, the numbers
are staggering. In Haiti, 92 percent are
threatened with extinction and 80 percent
in the Dominican Republic. Jamaica, and Cuba
also face similar peril. Although the picture
is less bleak in the United States, at least
51 species are endangered.
So the question is what causes such a large
scale decline ?
There are a variety of reasons for some losses,
while others remain a mystery.
For example, in the United States and Europe,
agricultural fertilizers run off into rivers
and wetlands, causing deformities and reproduction
A fungal disease is wiping out amphibians
in large numbers in America, the Caribbean
and Australia. Generally dry weather makes
them susceptible to this deadly disease because
it infects the skin of adult amphibians.
So, scientists believe the epidemic is worse
in drought years and may be exacerbated by
climate change. Now, many moist tropics are
experiencing periodic droughts which may
be the result of shifting worldwide rain
In the developing world, deforestation causes
soil erosion and muddy water from erosion
is often lethal to tadpoles because it kills
the algae they feed on. And when wetlands
are drained for human habitation, amphibians
lose places to live and breed.
In Asia and south America, the marketplace
is also one of causes. For example, in China,
giant salamanders are considered a delicacy.
In conclusion it's no wonder that many species
of amphibians are now on the brink of extinction.
As they are vulunable to pollution and climate
change, they are kind of "the canaries
in the coal mine." And their impact
on the food chain can also be a problem because
they are important food for many birds and
reptiles. You might remember the recent extinction
of Japanese Crested Ibis, TOKI.
To reverse this global trend, we should start
a campaign to preserve their habitat, tackle
pollution, and also global cooperation is
necessary to address issues of climate change.
Captive breeding programs will also make
a big difference.
In some parts of the world, conservationists
have been working with local partners. In
Sri Lanka, they are working to nurture forest
damaged by dry climate and logging so that
the forest can retain more rain water. This
forest reconstruction plan will also prevent
soil erosion, so people can grow crops and
amphibians can live in humid conditions.
I hope it's not too late to save many of
the most threatened amphibians as today's
frog is tomorrow's man.
Thank you for your attention.