The die-off occurred at the Angostura site in the Puyuhuapi Channel and was reported to state aquaculture service Sernapesca on April 16.
On March 5, AquaChile reported a die-off of 27,078 fish at the same site. The mortality was attributed to a decrease in dissolved oxygen content.
The most recent mass mortality event is the fourth to have occurred in Chile this month.
At the start of the month Invermar lost 861,000 coho salmon at its Tepun site near Quellón, Los Lagos region, because of a bloom of the toxic microalgae Cochlodinium sp. The fish had an average weight of 780 grams.
On April 12, Marine Farm notified Sernapesca about the death of 10,000 Atlantic salmon with an average weight of 4.3kg at its Mellimoyu farm in Aysén, also because of Cochlodinium s.
Two days later Mowi informed Sernapesca about the deaths of 15-20,000 Atlantic salmon at its Pulelo site in the northern Chiloé sector. The die-off was caused by a decreased dissolved oxygen content and the presence of microalgae such as Chaetoceros cryophilus and Cochlodinium sp.