x Abu Dhabi, UAESunday 23 July 2017

The water of life… and death for Al Ain's growing population

The man-made lake contains desalinated water piped for Al Ain. For the growing population, it means life, but for the midas fly it could mean death.

A midas fly buried in a sand dune laying its eggs. Credit Bridget Howarth.
A midas fly buried in a sand dune laying its eggs. Credit Bridget Howarth.
AL AIN // For a few short weeks, a tiny white fly is making its annual appearance on sand dunes across the Arabian peninsula.
From late last month until early next month, midas flies will perform a ritual of walking backwards up the dunes before burying themselves up to their eyeballs in loose, dry sand. There, they will lay their eggs.
But they are under threat, and from the rarest of desert intruders - a lake.
Near Al Ain, the man-made lake contains desalinated water piped from the Arabian Gulf. For Al Ain's growing population, it means life. But for the midas fly, it could mean death. The fly's strong relationship with ancient dune systems has earned it the dubious privilege of endangered species recognition.
Brigitte Howarth, an entomologist and assistant professor at Zayed University, would like to see it on a list of insects that indicate a healthy and relatively undisturbed environment.
"There is a case in the UAE to make some indicator species for certain habitats," said Dr Howarth. "We should try to do whatever we can to protect those species."
The midas fly, Eremomidas arabicus, was first identified in 1961, but largely forgotten in the UAE for 45 years until one was sighted in Umm Al Qaiwain in 2006.
And still they are seen only rarely - Dr Howarth has not seen one in Al Ain since 2010, and suspects the humidity around the new lake, which was created about seven years ago, is to blame.
"I don't know for sure but I am almost certain we will not see it there again," said Dr Howarth. "I'm sure that at the lake we can no longer see them because the lake has encroached on the dunes."
It is hard to know what the consequences might be of losing the midas fly from the area because so little is known about it.
It was only in 2010 that Dr Howarth discovered specimens were always covered in sand when she sighted one walking backwards to lay its eggs. The sighting solved the riddle of how it laid its eggs, which was being studied by a scientist in Italy.
As the custodian and curator of the insect collection for the Abu Dhabi and Al Ain Emirates Natural History Group chapters, Dr Howarth keeps a keen eye on changes in the UAE's insect population. In her Al Ain home, she has a room filled with boxes of thousands upon thousands of insects.
And many remain a mystery. The longhorn beetle, Anthracocentrus arabicus grows to 12centimetres and is found only in natural ghaf tree forests.
The brown beetle, named for its 5cm antennae, has an intimate relationship with the ghaf. "We know that there is an association but we don't now what it is," said Dr Howarth. But only with natural forests; the insects shuns plantations.
It may be the irrigated trees' shorter roots that put them off, but no one knows for sure.
"These are the kinds of things that need to be studied by a PhD student or anybody who can find out more, and this is the case of most of the species that need to be recorded," said Dr Howarth.
"It's a problem. How can you give adequate mitigation advice or suggest conservation plans if you don't know exactly what exists and you don't know the interactions between the species?"
And new species are still being discovered - a recent four-year study, which concluded in 2010, led by the Dutch entomologist Dr Antonius Van Harten, found 85 entirely new species of arthropods (the phylum that includes insects, spiders and crabs) in its first three years alone.
The research detailed more than 1,000 UAE species, enough to fill four thick volumes. "There will be hundreds of others that we need to learn about," said Dr Howarth.
Her shelves are still stacked with jars of insects preserved in ethanol, leftovers that have yet to be identified and enough, she believes, for a fifth volume.
Such volumes are particularly important for the UAE, where the transitory nature of the expatriate community carries the risk of rapidly losing institutional knowledge unless it is well organised.
The UAE's first enthusiasts started collecting and cataloguing insects in the 1940s and 1950s, a task that was revived in the 1980s by the newly founded Abu Dhabi chapter of the Emirates Natural history group. The group's collection was forgotten in storage until it was rediscovered in 2005.
Such private collections have yielded great finds: in 2008, three species of jewel beetles (buprestidae) previously unknown in the UAE were identified thanks to a rediscovered collection, bringing the total at that time to 19.
"It is probably more difficult for insects to be recognised as threatened because it is more difficult for insects to be recognised," said Gary Feulner, the chairman of the Dubai Natural History Group.
Identifying which species are present is just the start. To work out whether they are under threat, their ecology must be studied.
"That kind of work has not been done for the UAE," said Dr Howarth. "We have the baseline data we just don't have the follow-up data, the follow-up assessment, the ecological assessment. We're getting very good at baseline, we're getting very good at knowing what exists."
For instance, populations may naturally fluctuate because of rainfall and plant abundance.
"With a few exceptions like the longhorn beetle, which attracted attention because of its size, we don't know very much about the association of specific native insects with specific native plants or environments in the UAE," said Mr Feulner.
"It is difficult to see through the fluctuations and detect or analyse any longer-term background trends relating to the overall health of the environment, whether pollution, overgrazing, global warming or other[wise]."
An absence could indicate environmental change - or not.
"Environments are changing and, with the reality of climate change, increased pollution, water extraction from ground water and introduced alien species, there is certainly a need for indicator species ... [which] are easier to monitor than the environmental variable itself," said Dr Andrew Gardner, a former associate professor of Zayed University.
While indicator species are useful, their presence does not mean a habitat is safe for the future.
"They indicate a very specific kind of habitat but that doesn't mean that a habitat isn't under threat," said Dr Howarth. "You end up with a threatened environment because an island already has more stresses than an open habitat, where for example moving between spaces is more easy for species."
Even landscapes that look pristine are often fragmented.
"The midas fly is in a habitat that indicates ancient paleodunes," said Dr Howarth."But again it has begun to be heavily impacted because [those dunes do not] connect with other parts of the desert."
And there is a danger that some species may be lost before they are ever found.
Take Callytron monalisa, a copper, cream and emerald tiger beetle so beautiful it is named after Leonardo da Vinci's masterpiece. It is a top carnivore, and indicates a healthy mangrove ecosystem. Until it was discoved on Reem Island in 2007, it had only ever been seen in Iran. But the site on Reem is now occupied by high-rise towers.
"The habitat is now remodelled," said Dr Howarth. "It's no use saying we need biodiversity. What we need is people to feel they need it. We need to find a way for people to really start feeling that."
azacharias@thenational.ae
 
* This article has been amended since it was first published to correctly reflect that Brigitte Howarth is an entomologist and assistant professor at Zayed University, not UAE University as first mentioned.