Now it’s the Common Toad under threat from imports!
Saturday, August 09th, 2008 | Author: News Team
When well-meaning people introduced the American grey squirrel into Britain in the 19th century they could hardly have foreseen the disasterous impact it would have on our native red. Today, of course, the native red has been driven to the very fringes of Britain, although - with a little help from man - it is making something of a comeback in some areas.
Now experts claim that Britain’s native toad species are at risk from an imported infection that has already eradicated some of the world’s amphibian colonies.
Fortunately, the fungal disease is currently confined to Kent, where it is believed to have been introduced from frogs imported into this country.
However, the fear is that it could spread further and, in theory at least, completely wipe out the British toad population. This is the conclusion of British scientists, according to research published in the journal of the Royal Society last year.
Consequently environmentalists are urging tighter controls on the aquarium trade involving the importation of amphibians, to protect our native toads from this infection.
According to the experts, the chytrid fungus, or Batrachochytrium dendrobatidis (BD), infects the skins of amphibians such as frogs, toads, salamanders and newts. Such is its potency that a full one-third of all the losses in amphibian species recorded around the world are thought to be due to the disease. Research also indicates that although the frogs that brought the fungus to Kent have long since disappeared, it is likely that they have left a reservoir of infection in the environment. Now scientists claim that the deadly disease is being repeatedly brought into Britain through the world trade in amphibians.
A scientist at London’s Imperial College warned: “We strongly suspect BD is being introduced into the UK on a daily basis through the amphibian trade. Our borders are wide open to the introduction of this infectious disease.”
Meanwhile experts at the Institute of Zoology in London have developed mathematical models to evaluate various scenarios relating to infection in Britain’s common toad breeding populations. They found that the critical parameter was the length of time the fungus could survive in the environment away from its natural host. Their models suggest that there would be little impact on British toads if the fungus was only able to live outside its host for seven weeks. However, they also concluded that if it was able to survive in water for a year, the impact would be considerable - resulting in severe declines in the numbers of toads, and in some cases extinction in 10 years within infected areas.
Their research, which was first published in the Proceedings of the Royal Society towards the end of last year, makes clear the need to test all amphibians for the disease before they are brought into Britain. Indeed, the wildlife charity Froglife said it was important to make people aware of the danger to native amphibians. A spokesman for the charity is reported as saying: “It is thought that it could have been brought to the UK by exotic pet species, such as the African clawed toad, that have escaped or been deliberately released. It is vital strict controls on the health of imported animals are in place to help limit the spread of this devastating disease.”
Land & People consider the suggestion an eminently sensible one and recommend its adoption as a matter of some urgency.
Category: Amphibians, Wildlife | Leave a Comment