SANTIAGO (Reuters) - A growing outbreak of “red tide” has put salmon farms on alert in fish-rich southern Chile, an industry group said on Thursday, though its impact is still far less extensive than in 2016, when a much larger outbreak decimated fish farms.

Salmon Chile president Arturo Clement estimated that nearly 3,500 tonnes of salmon have been lost to the toxic algal bloom so far this year, the equivalent of 0.9 percent of the salmon biomass produced in Chile.

“We should be on alert these next two or three weeks because the phenomenon occurs in the (Southern Hemisphere) summer, so until climate conditions change we will continue to be concerned,” Clement said in an interview with local radio station Cooperativa.

Chile is the world’s No. 2 producer of farm-raised salmon.

The red tide - an algal bloom that turns the sea water red and makes seafood toxic - is a common, naturally recurring phenomenon in southern Chile, though scientists say rising water temperatures may be making them more frequent.

In 2016, an outbreak in Chile killed millions of fish, devastating the world’s second biggest salmon exporter and bringing losses of upwards of $800 million. {nL1N1EF16B}

“This bloom is different than the one in 2016, but we should still be concerned because these phenomena are occurring with more frequency,” Clement said.

Stocks in Chilean salmon farmer Invermar, among the most affected by the outbreak, dropped nearly 6 percent in mid-morning trading, to 110 pesos ($.18).

In a recent filing, the firm said it had lost 1,600 tonnes of salmon, the equivalent of approximately $8 million, though it said its operation and the losses were insured.