Trenches are Chile's last-ditch option if El Niño causes salmon catastrophy
The world's second-largest salmon producing nation is better prepared for challenges brought by the climate event than it was in 2016, and that includes disposal of morts
Published
Authorities in Chile may bury salmon mortalities in “sanitary trenches” on land if the El Niño climate event leads to the deaths of huge volumes of fish, parliamentarians have been told.
But that will only be allowed in the case of “a catastrophic event, surpassing all existing norms and technological advances”, said Alejandro Barrientos, deputy director of aquaculture at Subpesca, the Undersecretariat for Fisheries and Aquaculture.
Barrientos was speaking at a session of the Fisheries and Aquaculture Commission of the Chilean parliament’s lower house, the Chamber of Deputies.
During the session, the risks and solutions to possible harmful algal bloom (HAB) events driven by the current El Niño were reviewed in detail, along with the actions carried out by authorities such as Subpesca, government-backed fisheries and aquaculture research institute IFOP, the Navy, and Chile’s national disaster prevention and response service, Senapred (Servicio Nacional de Prevención y Respuesta ante Desastres).
Dumped in the sea
Deputies (MPs) expressed fears that the climate event could cause a HAB even worse than that of 2016, when the industry suffered mortalities that exceeded 40,000 tonnes and had to be dumped into the sea.
Barrientos said: “It is important to clarify why the spill (dumping) occurred: it was due to an uncoordinated or slow action to remove the mortality from the farming cages, which led to decomposition and the generation of hydrogen sulphide, which is toxic and could not be left on land, so it was taken to the sea.”
Modifications to aquaculture management regulations, HAB early warning systems, and improved contingency plans have been aimed at encouraging companies to remove dead fish, explained Barrientos.
There is also a monitoring system in place at each fish farm, with some having the technology to photograph the microalgae, upload the images to the cloud, and analyse their type and toxicity, allowing for the activation of microbubble or upwelling systems to protect the fish.
Prepared for the worst
“It is possible that an event larger than the one in 2016 could generate high-impact mortality, and in that sense, there is a risk that the debris could not be removed and would decompose. For this reason, we are working under the auspices of Senapred to identify ways to act in the face of such a scenario,” Barrientos stated.
In such circumstances, sanitary trenches or sanitary cells would be created to dispose of the mortality and prevent it from being dumped into the sea.
