Data used as provided from data sources.
The indicator is available for years 2009 (2001-2006 average), 2010 (2003-2007 average), and with partly new methodology, 2014 (2007-2011 average).
Sporadic future updates foreseen by the HELCOM-EUTRO-OPER project, intervals or dates not yet decided.
Data available as raster dataset for the Baltic Sea´s basins. In latest release Åland basin is missing (no data was provided to HELCOM).