thousands of dead fish were found washed up along the coastal areas of Thiruvananthapuram in the third week of October. According to the department of fisheries, the fish belong to a group called file-fishes of the Balistidae family, locally known as klathi. The department said spontaneous changes in the deep sea may have caused the mass deaths. However, mortality of other fish species was not observed.

A study team has been constituted to conduct a detailed investigation. The team, comprising officials from the department of fisheries and marine biology scientists, will analyse water samples.

Mass deaths of fish is not new to Kerala. During 1950-54, 1960-62 and 1971-72, mass mortality of klathi fish were recorded. In 1972, the dead fish were in the region of around 410 tonnes. This year, however, the figure is less than a tonne. The investigating team is expected to explain why these deaths occur periodically.

Meanwhile, a high-level team that visited the area has issued a warning against the consumption of the dead fish. It has also instructed local authorities to bury the dead fish in deep pits. Klathi is found between Kollam district of Kerala and Kanyakumari in Tamil Nadu. It does not have great commercial value because of its high oil content. It is usually consumed by local people when the availability of other fish is low.