Dubai: Dead fish floating on the surface of the water at Dubai Festival City were spotted several storeys up by residents in the area on Tuesday.
The normally blue water of Dubai Creek appeared grey in colour and the floating fish carcasses were spotted four floors up by one resident.
On closer inspection, big and small silver fish could be seen on the shores near Festival City and under Garhoud Bridge in small clusters intertwined with floating rubbish like wrappers, plastic bags, bottles and ropes.
"This morning I saw there were a lot of fish on the water. I have never seen this before but there were too many fish," said FK, a Festival City resident.
"They were already dead though I could see that and they were moving with the current but they didn't really disperse for a few hours," he told Gulf News.
Pollution, high temperatures, eutrophication, or algae blooms could be the causes behind the death of the fish, said Christophe Tourenq, manager, science and research, Emirates Wildlife Society-WWF.
Eutrophication, the increase in chemical nutrients such as nitrogen or phosphorus in an ecosystem can overburden it, reduce oxygen and impact fish life, he said.
"This usually happens if sewage or algae is present in too high quantities."
"Algae blooms can affect the toxicity of the water and depending on the bacteria can cause mortality of fish," added Tourenq.
"I have no idea what the water quality of the creek is like but all these phenomena could be behind the dead fish. Waterways that are not renewed frequently or quickly enough can reduce the amount of oxygen in the water," he added.
In 2004 thousands of fish washed up along Dubai Creek and Al Mamzar Lagoon and municipality workers were seen picking up the dead fish by the crate.
At the time Redha Salman, head of the Environment Protection and Safety Section, Environment Department at Dubai Municipality ruled out pollution as the cause of death calling it a seasonal phenomenon.