For the first time, discharges of fertilizer have decreased giving the body of water off Sweden's east coast a chance to recover.
The Baltic Sea has started its environmental turnaround due in part to the construction of new treatment works in Poland following the country's entry into the EU. Furthermore farmers in Denmark and Sweden have improved fertilizer management.
The first significant effects of the change will not be felt for 30-50 years however, according to a report in Svenska Dagbladet (SvD).
The research has been compiled by Fredrik Wulff at Stockholm University who has made the new calculations on commission from the Baltic Marine Environment Protection Commission (HELCOM).
"A very positive surprise," Wulff said of his results to SvD.
Discharges of phosphates and nitrogen have been substantial since the 1970s. Variations have to date been ascribed to natural causes - such as rainfall.
Levels of pollutants have ultimately reached levels that have disturbed several functions of the sea's ecosystem.
Oxygen levels have declined in the water and areas of the sea-bed devoid of oxygen have expanded at the same time as poisonous algal blooming has become a regular occurrence.
Several years ago the ecosystem shifted from nutrient-poor to eutrophication.
Environmental ministers from the countries around the Baltic Sea agreed in 2007 on goals to re-establish natural levels on discharges. This means that the annual emission of phosphates needs to decline by 15,000 tonnes per annum and nitrogen by 137,000 tonnes.
It has now been shown that levels of these materials have declined for the first time - by 3,000 tonnes and 50,000 tonnes respectively.
"The measures that have been taken have begun to have an effect," Wulff said.
The new treatment works process the phosphates and the improved management of fertilizers reduces the nitrogen emissions.