Pattaya, Chonburi– May 18th, 2026: Pattaya City officials have stepped up efforts to track the invasive “blackchin tilapia” following recent discoveries along Pattaya Beach, raising concerns about potential damage to the marine ecosystem and the city’s tourism reputation.
Deputy Mayor Krisana Boonsawat led an on-site inspection of the affected beach area on Monday, accompanied by Chonburi provincial MPs, Pattaya City councillors, Chonburi Provincial Administrative Organisation members, officials from the Chonburi Provincial Fisheries Office, and members of the media. No fish were found during the inspection.
Fisheries officials explained that the blackchin tilapia tends to appear in coastal areas when freshwater mixes with seawater. The absence of such conditions on the day of the inspection accounted for the lack of sightings.
The Department of Fisheries has confirmed that the species discovered is indeed the blackchin tilapia (Sarotherodon melanotheron). Authorities believe the fish were swept into the sea during periods of heavy rainfall, when water from canals and brackish sources flowed into the ocean, carrying schools of the fish toward Pattaya Beach.
While blackchin tilapia can survive in freshwater, brackish, and marine environments, they thrive and breed most successfully in brackish waters near river mouths. These areas are considered high-risk zones for the species’ spread.
Fishermen conducting trial net-casting in the area recently reported catching large numbers of juvenile blackchin tilapia, heightening fears of rapid population growth. Officials worry that an unchecked increase could disrupt the local marine ecosystem, harm native species, and tarnish Pattaya’s image as a premier tourist destination.
The Department of Fisheries has urged the public to refrain from releasing the fish into natural waterways and is calling for continued close monitoring. Authorities plan to implement ongoing control measures to prevent further spread and mitigate long-term impacts on coastal ecosystems.
