Algae toxins and nutrient concentrations will also be monitored.
Aranda sets sail from the port of Kotka on Saturday. The Finnish Environmental Institute’s research vessel will also call in at St. Petersburg for a public exhibition of its work.
The Baltic is the most radioactive sea in the world. Most radiation has seeped into the sediment at the floor of the sea. The largest single dose resulted from the aftermath of the Chernobyl nuclear disaster 25 years ago.