At the moment only some of the Mediterranean countries have developed a boundary approach for the assessment of eutrophication and no general assessment criteria have been agreed for the Mediterranean area for the key nutrient concentrations in the water column. This assessment effort was based only on the presentation of the geographical variability of some key nutrients (DIN – dissolved inorganic nitrogen and TP- total phosphorous; µmol L-1).
For the presentation of the data Box and Whiskerplots are used. Information contained in the plot are Hspreads (interquartile range - the absolute value of the difference between the values of the two hinges) and fences that define outside and far outside values:
Lower inner fence = lower hinge - (1.5 • (Hspread))
Upper inner fence = upper hinge + (1.5 • (Hspread))
Lower outer fence = lower hinge - (3 • (Hspread))
Upper outer fence = upper hinge + (3 • (Hspread))
The whiskers show the range of observed values that fall within the inner fences. Because the whiskers do not necessarily extend all the way to the inner fences, values between the inner and outer fences are plotted with asterisks. Values beyond the outer fences are plotted with empty circles.
UNEP/MAP’s Pollution Programme (MEDPOL) has a monitoring programme since 1999, based on the contribution of data from Mediterranean countries, including nutrients.
In this assessment, aware that for most of the northern Mediterranean countries data are available also in other databases (such as EEA, EIONET, EMODnet), only datasets obtained from the MED POL Database for nutrients were used. Data availability by country were as follows:
Albania (2005-2006), Bosnia and Herzegovina (2006-2008) Croatia (2009, 2011-2014), Cyprus (1999-2015), Egypt (2009, 2010), France (2009, 2010), Greece (2004-2006), Israel (2001-2012), Montenegro (2008-2012, 2014-2015), Morocco (2006,2007), Slovenia (1999-2013, 2015), Tunisia (2002-2013), Turkey (2005-2009, 2011, 2013)