In the period 1960-2019, the mean sea level along the Slovenian coast increased by 11 cm. On average, this means by 1.8 mm/year and in the last 20 years by 4,4 mm/year. It is estimated that the increase of the middle sea level is affected by global see level increase, and in the last period also by extreme weather conditions in the region. In the last twenty years, at the Slovenian and in the Adriatic coast sea level has been rising faster than the European and global trends.

Phytoplankton biomass, expressed as chlorophyll a concentration, reflects nutrient loading in the marine environment. Chlorophyll a concentrations shows a trend towards improvement in the status of the Slovenian sea, as the ecological status has been assessed as high or good over the last period.

Based on monitoring data for the period 2006–2008, five Slovenian marine water bodies were classified as being in a poor chemical state. This state was determined by values that exceeded the environmental standard of the quality of tributyltin compounds, which have been monitored at the level of the European Union since 2007. Three marine water bodies have been determined to be in a good or very good ecological state.