Mass Stranding of Small Fish in Penghu's Wude Stone Weir Attracts Crowds

Central News Agency, Penghu County, June 13 A rare phenomenon occurred today at a stone weir in Wude, Penghu, where a large number of small fish, including surgeonfish (commonly known as 'Jiadong'), Qiugu, and Wanmi, were stranded on shallow flats inside the weir during low tide. The fish, which had entered the area during high tide to feed on seaweed, were unable to retreat as the water receded and remained trapped until the next high tide. The unusual sight quickly attracted crowds of local residents and visitors to the intertidal zone.

Tidal movements in Penghu waters, locally referred to as 'flowing currents,' meant that despite the hot weather, many people ventured onto the exposed tidal flats around 3:30 p.m., when the lowest tide occurred. They engaged in traditional activities such as fishing, collecting shells, and gathering abalone. Meanwhile, owners of the stone weirs conducted routine inspections, maintaining this centuries-old fishing practice.

In the afternoon, visitors exploring the stone weir in the Magong Wude area discovered large groups of small migratory fish lying motionless in shallow pools. Due to the intense heat, many of the fish appeared lethargic and near death.

Local fishermen explained that these fish enter the weirs during high tide to feed on algae along the shoreline but become trapped when the tide recedes too quickly. They can only return to the open sea once the tide rises again.

Known as 'stone weirs,' these traditional fishing structures are built from basalt rocks along Penghu's intertidal zones and function as passive fish traps. They represent one of the most ancient fishing methods in the region. Across Penghu's coastline, an estimated 600 or more stone weirs of varying sizes exist. Most are well-preserved or have been restored, though some have been buried by silt over time. The largest concentration is found around Jibei Islet in Baisha Township, with over 90 weirs. Weir owners take turns monitoring them, and occasional catches include skipjack tuna, rabbitfish, and red snapper.