BAHRAIN's ecosystems are under attack from invading foreign species, an environment expert warned yesterday.

Animals are either being brought into the country by ships or are released into the wild by humans, revealed Bahrain Natural History Society member Abdulqader Khamis.

He said that terrapins, cats, birds and other animals - including the Indian mongoose - are threatening Bahrain's ecosystems, attacking other species and even pose a risk to humans.

As a result, he urged owners of unwanted pets against releasing them into the wild to help limit the problem.

"There is a public misconception that it is better for a pet to be released into nature, but it's not good for the environment," Mr Khamis told the GDN.

"If they don't want the pet they should give it to a friend, or an organisation like the Bahrain Society for the Prevention of Cruelty to Animals (BSPCA), but they shouldn't release it."

Mr Khamis said feral cats, which are the offspring of domestic cats, pose a threat to some bird colonies on islands around Bahrain.

He said they had already been introduced to Hawar Island and there was a worry they could find their way to smaller surrounding islands, which are home to important bird colonies.

"If these feral cats got to other offshore islands they will clear the colonies of birds, such as herons," said Mr Khamis, who is also a senior environmental specialist at the Public Commission for the Protection of Marine Resources, Environment and Wildlife.

"The largest breeding colony in the world for the Socotra Cormorant is found on Suwad Al Janubiyah, Hawar.

Mr Khamis also revealed that pet owners had released the popular Red Eared Terrapin into the wild and it was reportedly responsible for transmitting diseases, such as salmonella, to humans and even attacking people.

They carry salmonella in their intestines, which can reportedly be contracted simply by touching them.

Mr Khamis was speaking prior to a lecture on Invasive Alien Species in Bahrain: The Overlooked Threats, held at the Royal College of Surgeons in Ireland-Medical University of Bahrain in the Seef District last night. The public lecture was organised by the Bahrain Natural History Society.

"I want to raise public awareness of these problems so they will think before they let their bird, cat, or terrapin loose," he said.

However, Mr Khamis said other invasive species had also come to Bahrain through trade and migration.

He said climate change could also be a factor in the increase of invasive species, but it was very difficult to prove scientifically.

The environmentalist said the mynah bird was now widespread in Bahrain and was listed in the One Hundred World's Worst Invasive Alien Species.

It attacks other birds and turtles and is very invasive, he said.

"The Indian house crow came to Bahrain in the early 1990s and it's affecting the house sparrow," he added.

"They attack their nests, cattle, frogs and everything.

"The Indian mongoose has entered the country via commercial ships from India.

"It is widespread in the country and attacks poultry, mainly chickens, as well as dogs."

Mr Khamis said invasive alien species had various health and economic impacts.

He said although there were no ready figures for Bahrain, in the US in 2001 invasive alien species were responsible for $137 billion (BD51.786bn) loss to the economy.

"Many countries in the world have national plans to combat alien species," said Mr Khamis.

"Bahrain has a programme to eradicate crows and a management plan for looking after others, but there is no comprehensive programme for invasive species in Bahrain and it's very costly."