August 31, 2023
GEORGE TOWN – The coast of Teluk Bahang, where thousands of fish were reported killed by the recent algal bloom, has been found to be lacking in oxygen to sustain marine life.
The Environment Department (DOE) said, in a statement Wednesday (Aug 30), that tests taken at waters near the affected fish farms found the samples to be low in oxygen.
“Several samples were taken and initial analysis found that the amount of dissolved oxygen in the water was at 1.59mg/L to 2.09mg/L for depths between 1m to 4m.
“Investigations found that it does not fulfil Class 2 of Marine Water Quality Standard to support aquatic life,” the department’s director-general Datuk Wan Abdul Latiff Wan Jaffar said.
He said based on observations at the two monitoring stations in Teluk Bahang, the water in the area has never been polluted.
“The area only consists of rural communities where most villagers are fishermen or in the tourism industry, with no heavy industries nearby.
“Both water treatment plants nearby had fulfilled their standards,” he said.
Meanwhile, the Penang Fisheries Department will continue to take samples periodically to monitor the density of the Noctiluca scintillans algae in waters off Teluk Bahang, which has been experiencing a “red water” phenomenon since Saturday (Aug 24).
In a statement, the department said it will monitor the density until the situation reaches a safe level.
“Preliminary results of the analysis carried out by the Batu Maung Fisheries Research Institute found that the algae is non-toxic.
“It is from the Noctiluca scintillans species and is not dangerous to humans,” said the department.
It said a very high density of phytoplankton cells in those waters can cause fish to die, especially those in cages due to a decrease in dissolved oxygen.
The Department said a similar situation had happened in Kuala Gula, Perak, in 2016, which had caused fish in cages to die.
The department has also proposed a number of mitigation measures for fish cage farmers in the affected areas such as immediate harvesting of all market-sized fish if there are signs of drowning or death.
It said fish cage breeders are also advised to reduce the density of fish in cages and monitor the dissolved oxygen content.