“We're investigating ... to establish the physical parameters of temperature, electric conductivity and, above all, the oxygen,” local environment official Victor Casanova told reporters.
But local fishermen suggested the deaths could have been caused by local power stations that use seawater as a cooling agent.
The power firm, Endesa Chile, denied the allegations.
The company project manager said that their own studies indicate the die-off “is due to the flow of deep waters coming from the continental platform, induced by currents of wind on the ocean.”
Last year, large numbers of dolphins and birds died mysteriously to the north in coastal Chile.
Some blamed the use of powerful underwater sonar used by oil exploration offshore for the fatalities.
Photos: Jose Luis Saavedra