Marine traffic has been temporarily suspended in parts of Abu Dhabi’s waters to protect two whale sharks spotted in the areas.
Abu Dhabi Maritime said use of boats, jet skis, kayaks and paddleboards was banned in the waters near Aldar headquarters, Al Raha and Al Bahia.
Swimming is allowed but only in dedicated areas, the notice said.
It said the ban was effective immediately “to protect these endangered [whale] sharks frequently swimming in Abu Dhabi channels”.
This week, residents were warned to steer clear of the whale sharks after they were consistently spotted in those areas over the past two months.
Environment Agency Abu Dhabi, who are monitoring the fish, said a juvenile four-metre whale shark returned to Al Raha after last being seen in the area, near Aldar headquarters, a week ago.
The agency had been monitoring him for six weeks and, after noticing he lost weight, began supplementing the his diet with krill supplied by the National Aquarium Abu Dhabi.
The agency is also monitoring a second whale shark nearby in Al Bahia. It warned people to protect the seven-metre male by not swimming or diving with it. Fishing is also banned in the area.
Maitha Al Hameli, lead specialist for Marine Threatened Species and Habitats at the agency, said the sightings were uncommon but also not completely unexpected.
“Every year, or second year, we get one or two whale sharks visiting Abu Dhabi emirate. It is generally a fleeting visit, if people are lucky they see them, and they move on very quick. This year we have had two visit our waters,” she said.
“They have stayed for over seven weeks now, which is unprecedented.”
The whale sharks are thought to have followed a plankton bloom into the area before becoming disorientated in the canals and unable to find their way back out to the open waters of the Arabian Gulf.
“Over this time we noticed the smaller Al Raha whale shark lose considerable weight – he is really skinny and his colour has changed – so through our agreement on environmental co-operation and wildlife with the National Aquarium, we have been supplementing his food with krill,” Ms Al Hameli said.
The agency plans to gently return the whale sharks back to sea but said it would “share more news on this soon”.
Whale sharks, which can grow to the size of a bus, pose no threat to humans but are listed as vulnerable species.
Though they are the largest fish in the sea, whale sharks feed on small crustaceans. They are filter feeders, opening their large mouths to suck in water and filter out any plankton or krill. The remaining water is forced back out through their gills.
They are believed to live as long as 130 years and are found in all warm waters of the world, although only about 7,000 are thought to be left in the wild.
On Thursday, the notice from Abu Dhabi Maritime asked vessels passing in the area outside the closed channels of Al Raha and Al Bahia to reduce their speed to 30kph or less in case the whale shark has moved.
Anyone who spots the whale shark has been asked to keep their distance, “admire it” from afar and contact the agency on 800 555.