Preliminary test results have found a massive algal bloom in Kep Bay in early April did not produce harmful toxins, although the Ministry of the Environment plans to follow up with additional research into possible causes.
According to a ministry press release on Friday, the bloom was a “red tide” – a phenomenon that can potentially involve a species of plankton that releases substances toxic to humans, but in this case did not. The document identifies rising temperatures due to climate change as the cause.
The ministry’s general director of environmental protection, Heng Nareth, yesterday said the ministry measured record-breaking water temperatures at the time of the bloom, which he said was the first such event he had seen in the Kingdom’s salt waters.
“We measured 33 degrees centigrade, which made the sea grass die,” he said.
The dead grass, combined with high nutrient content in the water, fed the bloom, which consumed oxygen in the water and led to the death of marine life.
Nareth said the ministry will test rainwater run-off during the rainy season to identify additional causes.
Kan Ponhrith, from marine resource management NGO CORIN Asia, yesterday pointed to several potential causes not yet acknowledged by the ministry, including water released from fish farms, untreated sewage and destructive illegal fishing practices.