GEORGE TOWN, Dec 7 — The Prangin Canal at the Sia Boey archaeological park, which became a popular public space since it opened to the public last year, has led to people dumping other species of fish and even tortoises into the canal.
Komtar assemblyman Teh Lai Heng said originally the canal has a controlled number of tilapia and koi fish to maintain algal growth and prevent mosquito infestation.
“As this place became popular among the locals, they started feeding the fish and introduced other fish into the canal such as patin and catfish,” he said.
By October this year, there was a population of 1,400 tilapia, 250 koi, eight patin, four catfish and two tortoises in the canal.
Due to the overpopulation of fish in the canal, Teh said it had altered the balanced ecosystem of the canal and this led to a thick layer of sludge coating the canal.
He said the canal was designed as a closed-loop and self-sustaining water body and the filtration system was made for a small number of fish to control larvae growth in the canal.
“PDC had to implement thorough cleaning works of the canal to restore the ecosystem and ease the canal maintenance,” he said, referring to the landowner, Penang Development Corporation (PDC).
The entire fish and tortoise population were removed from the canal and cleaning works were conducted on the canal between October 27 and November 19 at a cost of RM18,500.
The cleaning works included cleaning the bio-filter chambers, servicing the filtration pump system and disinfecting the canal before refilling it with water.
“About 120 koi are reintroduced into the canal and we will be putting up signages to remind the public not to feed the koi and not to introduce other types of fish into the canal,” he said.
He said the canal has a balanced self-sustaining ecosystem so the koi will have sufficient algae and larvae to feed on.