The aim of the study is to assess the status of the marine environment in the Estonian waters (including EEZ).

Temperature, salinity, water transparency, oxygen content is measured and samples are collected for analyses of nutrient content and biological parameters. Six seasonal cruises are carried out in the Estonian waters with measurements at least at 20 stations. Autonomous measurements are conducted using a flow-through system (Ferrybox) installed onboard a passenger ferry Tallinn-Helsinki.

Samples are collected 12 times a year from 3 monitoring points by the Ferrybox system, where nutrient and chlorophyll a content and phytoplankton species composition, abundanca and biomass are analyzed.