One of the world’s most invasive species has been found in the UAE for the first time.
The Giant African Land Snail, which grows up to 20cm long, was discovered in Al Wathba on the outskirts of Abu Dhabi city.
The creature may have arrived on imported plant material, and although there is no record yet of it elsewhere in the country, experts said eliminating invasive species can be difficult.
In a new study, scientists analysed nine snails collected last year.
They analysed the snails' genes and found the nine belonged to four distinct groups, suggesting multiple invasion events. The researchers said the species’ arrival was almost certainly recent.
Published in the Biological Journal of the Linnean Society, the study describes how the snail, native to East Africa but introduced to new countries since the 1800s, is "one of the world's most invasive species" and may have caused significant harmful economic, ecological or health effects in at least 52 countries.
The study also looked at alien populations of the snail in China, India and West Africa.
Particular alien species sometimes multiply out of control because they have no natural predators in their new habitats, and the creatures or plants they eat have not evolved natural defences to them.
By killing or outcompeting them, invasive species harm their indigenous counterparts and have been described as the biggest threat to native animals and plants after climate change and habitat loss.
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UAE's most endangered species – in pictures
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The sand dune cat (Felis margarita) is a nocturnal creature that lives in shallow burrows and hunts rodents. Research published in 2005 indicated that only 250 remained in Abu Dhabi emirate. Courtesy, Al Ain Zoo -
The Arabian leopard is currently listed as critically endangered. Pawan Singh / The National -
This is the first sighting of the rare Rüppell's fox (Vulpes rueppellii) in 13 years. Environment Agency – Abu Dhabi -
Whale sharks are known as jinbe zame in Japanese, inspiring their newly discovered residents' name.. Getty Images -
Arabian Caracal (Caracal caracal) - IUCN status: least concern - thought to be extinct, the environment agency captured daytime and nighttime footage of the creature for the first time since 1984. Courtesy EAD -
Green turtle (Chelonia mydas) - IUCN status: Endangered - The UAE is one of 140 countries where the green turtle is a native species; numbers have fallen worldwide - Two years ago Emirates Wildlife Society – WWF launched Gulf Green Turtle Conservation. Courtesy Paul Velasco/EWS-WWF -
Socotra cormorant (Phalacrocorax nigrogularis) - IUCN status: Vulnerable - Found on islands of the coast of several Gulf states, including the UAE - Threatened by development and oil spills, the species has a total population of less than half a million. Courtesy- Rob Gubiani -
Emirati leaf-toed gecko (Asaccus caudivolvulus) - IUCN status: Least concern - Only found in mountainous regions of north-eastern UAE and northern Oman - More recent research suggests it actually consists of three species, one of which is unique to the UAE – making it the country's only endemic vertebrate – and threatened by development. Photo Courtesy: Johannes Els. -
Sea cow (Dugong dugon) - IUCN status: Vulnerable - Locally, boat strikes and fishing net entanglement is a threat, although there are major conservation efforts - The population in UAE waters is thought to be several thousand -
The Crested Porcupine, a rodent thought to be extinct in the UAE, was recorded by camera traps in Abu Dhabi. Environment Agency – Abu Dhabi -
Gulf sand gecko (Pseudoceramodactylus khobarensis) - IUCN status: Least concern - Found widely in the Arabian peninsula, especially in the UAE - This species is not endangered but its population is declining, and in the UAE it faces threats from the development of coastal sabkha habitat. Photo courtesy-Salvador Carranza) -
Keyserling's wonder gecko (Teratoscincus keyserlingii) - IUCN status: Not yet evaluated - Although this species is also found in Iran, the UAE population is the only one in Arabia - Heavily threatened by development, it could be driven to extinction locally, although the Mohamed bin Zayed Species. Pritpal Soorae / Environment Agency Abu Dhabi -
Hammerhead shark (Sphyrna mokarran) - IUCN status: Endangered - Widely distributed, but threatened by fishing for its fins and as accidental bycatch - Numbers have plummeted by four-fifths over the last quarter of a century. Image by © Norbert Wu/Science Faction/Corbis -
Hawksbill turtles, rated as Critically endangered on the International Union for Conservation of Nature Red List of Threatened Species, have begun laying their eggs on a beach in Dubai. Antonie Robertson / The National -
Arabian tahr (Arabitragus jayakari) - IUCN status: Endangered - Restricted to mountainous regions of north-eastern UAE and northern Oman - Worldwide population is probably below 5,000. ANTONIE ROBERTSON / The National -
Indian Ocean humpback dolphin (Sousa plumbea) - IUCN status: Endangered - Often become entangled in fishing nets - A recent census found 701 individuals, so the waters off Abu Dhabi have the world's largest single population. Roland Seitre / Minden -
The semaphore gecko is one of several species we have learned a great deal about in recent years. Getty Images -
The Houbara bustard is classified as a vulnerable species by the International Union for Conservation of Nature. Courtesy International Fund For Houbara Conservation -
Arabian oryx (Oryx leucoryx) - IUCN status: Vulnerable - Formerly listed as endangered, the UAE's reintroduction programme has helped to increase numbers - The wild population is about 1,200, just over half of which are UAE reintroduced individuals. Mike Young / The National -
Egyptian spiny-tailed lizard (Uromastyx aegyptia) - IUCN status: Vulnerable - Found in much of the Middle East in gravelly and stony areas, but numbers have declined - Two sub-species exist in the UAE, where it is threatened by habitat loss -
Green sawfish (Pristis zijsron) - IUCN status: Critically endangered - The largest sawfish, it can reach up to seven metres in length - This coastal species has declined across its range and has become extinct from some countries. AP Photo -
The Arabian tahr has been categorised as an endangered species, with a global population of less than 5,000. Courtesy TDIC -
Blacktip reef shark (Carcharhinus melanopterus) - IUCN status: Near threatened - Populations have suffered because of fishing - This species was spotted this year off the UAE's east coast
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The Giant African Land Snail eats crops and other vegetation and can spread bacteria that cause septicaemia in people and a roundworm associated with a severe form of meningitis.
Despite that, the snail is a popular pet – not least because it can grow to the size of a rabbit.
“Species such as the Giant African Land Snail have really high reproductive potential; they lay a lot of eggs and produce a lot of offspring, so their populations will increase in size quite rapidly,” said Prof Helen Roy, an invasive alien species specialist at the UK Centre for Ecology & Hydrology.
Although it reaches sexually mature first as a male, it goes on to become hermaphrodite, producing male and female sex cells simultaneously, allowing self-fertilisation.
As a result, Prof Roy said it could be “very difficult” to eliminate invertebrates like the snail once they became established in a new area.
The Environment Agency – Abu Dhabi was involved in the research and contributed to the recently published paper.
The organisation said there had been only “one record from one very localized area” of the snail in the UAE, adding that the creatures were being monitored as part of EAD’s “alien species” programme.
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The Giant African Land Snail that has been found in the Al Wathba area of Abu Dhabi. It is one of the world's most invasive species and has been found in 52 countries. All photos courtesy Environment Agency - Abu Dhabi. -
The creature may have arrived on imported plant material. -
Environmental chiefs are monitoring the situation.
“Since it was only localized, the area was checked and any visible snails collected,” a spokesperson said. “It could become a problem if the species became widespread.”
Species such as the Giant African Land Snail are “passive dispersers”, said one of the paper’s authors, Fred Naggs of the Natural History Museum in London.
“They are primarily carried on goods, mostly on imported plants or soil associated with imported plant material,” he said.
“It might only take a tiny egg to source a population. The only ways to guard against this are for thorough checks to be carried out on imported goods and for any outbreaks to be promptly identified and eradicated.”
In some countries, tens of millions of dollars have been spent trying to eliminate alien species because of the harm they cause, so preventing new species from arriving is “a much better option”, according to Prof Tim Blackburn, a professor of invasion biology at University College London not connected to the new research.
Dan Eatherley, a UK-based environmental consultant and author of Invasive Aliens, a book about invasive species, suggested they were not always as harmful to local flora and fauna as suggested.
“There are surprisingly few cases of an invasive species alone causing extinction,” he said.
“Other man-made factors are often as much to blame.”
