Mysterious dead fish on volcanic lake in Indonesia

Thousands of deadly fish covered the surface of Lake Maninjau in Indonesia's West Sumatra province. According to local fisheries officials, the phenomenon of mass mortality may be caused by sudden changes in weather conditions.

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A series of mysterious dead fish on Lake Maninjau in Indonesia

This is not the first time people living around Lake Maninjau witness this unusual phenomenon. At least 7,000 tons of fish from a floating fish farm on the lake died of sulfur poisoning and food residues were stirred from the bottom of the lake by a storm in 2009.

At that time, the West Sumatra Provincial Fisheries Authority reported that the mass death of fish was caused by the sulfur-rich cold water from the bottom of the lake being stirred to the surface due to unusual weather changes.

The agency said dead fish were poisoned by sulfur gas and they also detected a small amount of ammonia gas, which usually does not exist under normal conditions.

Maninjau Lake, 99.5 km ² wide, is a large crater in Agam district in West Sumatra province. The lake has a depth of about 500m with surrounding mountains. This is also one of the most tourist attractions in West Sumatra.