## 3 Results
### Ecosystem Service Assessments  
#### 3.2.1 Expert-Based ESA of the Mussel Mitigation Approach in Different Coastal Systems  
The comparison of the two expert-based ESAs focusing on commercial mitigation mussel farms in the coastal waters of Lithuania and Denmark (Table 5) shows that the expert groups of both countries assessed the changes of provisioning ESs by commercial mitigation mussel farming quite similarly and slightly positively (average increase of ESs by +1) (Table 5). Both groups were in agreement that the mussel farm scenarios had no effect on the ES \"Physical and bioenergy\".  
For regulating ESs, the most deviations between the two expert groups could be seen between the ESs \"Burial of nutrients and organic matter\", \"Primary productivity\", and \"Oxygen provision\". In contrast, the experts from Lithuania rated the changes in \"Burial of nutrients and organic matter\" slightly positively (mean value +1) and with no changes in \"Primary productivity\". The change in \"Oxygen provision\" was surprisingly rated negatively by Lithuanian experts (mean value = -2). Overall, it seems that experts in Denmark rated the changes in the regulating ESs higher compared with the experts in Lithuania.  
Within the division of cultural ESs, slight differences in ratings occurred between both expert groups for the ESs \"Bathing and sunbathing\", \"Recreation and water sports\", and \"Experimental use\". Here, the expert group in Denmark rated the changes in the above mentioned ESs slightly more positively than the expert group from Lithuania.  
\begin{table}
\begin{tabular}{l c c c c c} \hline \hline \multicolumn{1}{c}{**Measure**} & \multirow{2}{*}{**Flag Color**} & \multicolumn{2}{c}{**Stralsund**} & \multicolumn{1}{c}{**Athens Workshop**} & \multicolumn{1}{c}{**Klaipeda**} & \multicolumn{1}{c}{**Total**} \\  & & **Workshop (PM1)** & \multicolumn{1}{c}{**(PM2)**} & \multicolumn{1}{c}{**Workshop (PM3)**} & \multicolumn{1}{c}{**Amount**} \\ \hline Macrophyte measure (EE) & Green & 15 (50) [58] & 5 (31) [19] & 6 (40) [23] & 26 [44] \\ Mussel measure (EE) & Blue & 9 (30) [69] & 2 (13) [15] & 2 (13) [15] & 13 [22] \\ Mechanical measures (HE) & Yellow & 2 (7) [18] & 7 (44) [64] & 2 (13) [18] & 11 [19] \\ Geoengineering measures (GE) & Red & 0 & 0 & 5 (33) [100] & 5 [9] \\ No measure & White & 4 (13) [100] & 0 & 0 & 4 [7] \\ \hline Sum & & 30 & 14 & 15 & 59 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Amount of flags pinned for potential installation sites for different internal nutrient removal measures. The round brackets show the percentages per workshop, the square brackets show the percentage distribution across all workshops, and the curved brackets the total share of all measures pinned.  
Overall, and despite their different levels of experience with the mussel cultivation practice, both expert groups from Denmark and Lithuania rated the changes to the ESs by a commercial mussel farm scenario slightly positively overall. The results also show that the greatest and considerable disagreements in the rating of changes to ESs appeared for regulating ESs. The results show that an ESA can also be used to identify uncertainties and where a wider discussion is needed.