The voracious alien fish species Blackchin tilapia was among many fish, including Nile tilapia, found floating in Bangkok’s Makkasan swamp, prompting people to go to there to catch the fish on Monday.
Kornnit Buachan, the director of Ratchathewi district, said that he is worried about the discovery of Blackchin tilapia in the swamp and has consulted the Fisheries Department, the Department of Drainage and Sewerage of city administration and the State Railway of Thailand about ways to deal with the species, which appears to have spread to many watercourses throughout the country, particularly in Samut Sakhon and Nakhon Si Thammarat provinces.
Officials from the Drainage and Sewerage Department reported that they had closed the sluice gate for maintenance on Monday morning, resulting in a lowering of the level of oxygen in the water, causing the fish to float to the surface.
One of those who went to the Makkasan swamp for the floating fish said that he managed to catch about 100kg and planned to eat them himself and to distribute some to his relatives.
District officials will collect the remaining dead fish on Tuesday for disposal.
The swamp is connected to the Samsen Canal, from which water is drained into the swamp and discharged through drainage system into the Chao Phraya River. It is also reported that Blackchin tilapia have been found in the waters of Thon Buri district.
The Blackchin tilapia is a major threat to other fish and aquatic life, as well as vegetation in watercourses, because they eat almost non-stop and spread very quickly.
