Algal bloom alert in southern Norway

 The Norwegian Directorate of Fisheries said it has notified fish farmers in production area One, just north of the Skagerrak, setting out thewww.fishfarmermagazine.com/events-webinars/webinar-harmful-algal-blooms measures they may need to implement.

It says: “The algae, Pseudochattonella, could potentially reach Norwegian waters within 3–5 days. Models show that the algae moves via the outer part of the coastal current. It is currently uncertain where a potential bloom will hit the Norwegian coast.”

High mortality has been reported on the west coast of Denmark earlier this week. Data from the Institute of Marine Research’s (IMR) monitoring programme in the Skagerrak and on the Torungen-Hirtshals section showed that the potentially harmful alga Pseudochattonella occurred on the Danish side of the section in concentrations of up to 10 million cells per litre.

The IMR says these are densities that will cause mortality in fish. Observations made in Norwegian waters, in the outer part of the Oslo Fjord and on the southern coast have so far shown no presence in these areas.

It also says the species Pseudochattonella has formed large blooms a number of times in the Skagerrak region.

The largest were in 1998, 2001 and 2017, but there have also been smaller blooms in the area. Such blooms in the past have caused mortality in farmed and wild fish. This year’s bloom shows largely the same spread dynamics as the bloom in 1998.