## 3 Results  
### Estimation of Pressure Levels in Coastal Lagoons  
For the selected Mediterranean coastal lagoons, the relative coverage of the main groups of land uses in the catchment areas differed among sites (Figure 4), with a larger area of rainfed agriculture in most catchments. A clear predominance of irrigated agriculture was found for ALBU and KOTY. Urban uses were above 10% of the total catchment area only for ALBU, BIGU, CANE and THAU. Comparatively, other land uses, such as communication infrastructures, mining areas and dumps were scarcely represented in the catchments. In three of the studied lagoons, BIGU, NARB, URBI, natural land uses (forest, scrubs, other vegetated areas, bare rocks, beaches and water bodies) dominated, covering a greater surface area than the rest of the uses, classified according to CLC. Pressure levels regarding eutrophication, organic enrichment, acidification, and toxic pollutants, were estimated (Table 3) using the LUPLES method, from land uses in the catchments of the studied coastal lagoons. These pressure values were then correlated with the metrics assessing the ecological status (Table 4). For lagoons with more than one catchment the location of the sampling points was considered in order to select which metrics data had to be correlated with pressure levels of the respective sub-catchment. ALBU and KOTY, the sites with the highest relative area used for irrigated agriculture in their catchment, were those with the highest estimated levels of eutrophication pressure: above 40, as calculated by the LUPLES method (i.e., very high pressure level). Other sites, such as CANE, CABR, COMA, GELA or ITTY showed values above 20 for this pressure, also indicating a high pressure level. All the places presented values for eutrophication pressure above 10, and only the western basin of BIGU was below this threshold. Regarding the organic enrichment pressures, only ALBU showed values over 20, corresponding to a high pressure level, whereas the rest of the sites were around 10, with some of them even registering below this boundary level, indicating a low pressure level (i.e., ITTY, URBI, NARB center and south, and BIGU west). Acidification pressure was not significant in any studied site, with all the values being far below 10. Finally, pollutant pressures were  
Generally, metrics values showing poor and bad ecological status were positively correlated with the pollution pressure levels estimated by the LUPLES method (Table 4). Nutrient concentration, as indicated by ammonium, nitrite, orthophosphates, silica, total P and total N were generally positively correlated with eutrophication and specific pollutant pressure levels, with _p_-values \(<\) 0.01 (except for the total nitrogen and eutrophication pressure level, with a _p_-value of 0.084). Dissolved oxygen concentration positively correlated both with the pressures of eutrophication and specific pollutants, with Spearman values higher than 0.29 and 0.23, respectively (_p_-value \(<\) 0.01), whereas it correlated negatively with the organic enrichment pressure level (Spearman \(-\)0.31, _p_-value \(<\) 0.01). The acidification pressure level also significantly correlated with some of these metrics, probably due to covariation, as this pressure was estimated to be low in all the studied sites. The chl-_a_ concentration was positively correlated with both eutrophication and organic pressures. The benthic invertebrate index values, in EQR, significantly correlated with all four pollution pressure types, responding negatively to increases in each of the pollution pressure levels (Table 4). Macrophyte coverage--also as normalized data in EQR, joining the different metrics established per member state--showed a negative trend with increasing levels of pollution pressures, though these trends were not statistically significant. Apart from the correlation, linear regression analyses were carried out to explore the response of each metric value to the pressures identified.