An integrated Pan-European perspective on coastal Lagoons management through a mosaic-DPSIR approach.

A decision support framework for the management of lagoon ecosystems was tested using four European Lagoons: Ria de Aveiro (Portugal), Mar Menor (Spain), Tyligulskyi Liman (Ukraine) and Vistula Lagoon (Poland/Russia). Our aim was to formulate integrated management recommendations for European lagoons. To achieve this we followed a DPSIR (Drivers-Pressures-State Change-Impacts-Responses) approach, with focus on integrating aspects of human wellbeing, welfare and ecosystem sustainability. The most important drivers in each lagoon were identified, based on information gathered from the lagoons' stakeholders, complemented by scientific knowledge on each lagoon as seen from a land-sea perspective. The DPSIR cycles for each driver were combined into a mosaic-DPSIR conceptual model to examine the interdependency between the multiple and interacting uses of the lagoon. This framework emphasizes the common links, but also the specificities of responses to drivers and the ecosystem services provided. The information collected was used to formulate recommendations for the sustainable management of lagoons within a Pan-European context. Several common management recommendations were proposed, but specificities were also identified. The study synthesizes the present conditions for the management of lagoons, thus analysing and examining the activities that might be developed in different scenarios, scenarios which facilitate ecosystem protection without compromising future generations.

Reduction of Baltic Sea nutrient inputs and allocation of abatement costs within the Baltic Sea catchment.

The Baltic Sea Action Plan (BSAP) requires tools to simulate effects and costs of various nutrient abatement strategies. Hierarchically connected databases and models of the entire catchment have been created to allow decision makers to view scenarios via the decision support system NEST. Increased intensity in agriculture in transient countries would result in increased nutrient loads to the Baltic Sea, particularly from Poland, the Baltic States, and Russia. Nutrient retentions are high, which means that the nutrient reduction goals of 135 000 tons N and 15 000 tons P, as formulated in the BSAP from 2007, correspond to a reduction in nutrient loadings to watersheds by 675 000 tons N and 158 000 tons P. A cost-minimization model was used to allocate nutrient reductions to measures and countries where the costs for reducing loads are low. The minimum annual cost to meet BSAP basin targets is estimated to 4.7 billion Euro.

Impact of sampling frequency on mean concentrations and estimated loads of suspended sediment in a Norwegian river: implications for water management.

Reliable estimates of mean concentrations and loads of pollutants in rivers have become increasingly important for management purposes, particularly with the implementation of the European Union Water Framework Directive (WFD). Here, the Numedalslågen River (5500 km(2)) in southern Norway was used as a case study to evaluate the effects of sampling frequency on mean concentrations and estimated loads of suspended particulate matter (SPM). Daily monitoring data from five seasons (April/June-October/November 2001-2005) were analyzed, and three different load estimation techniques were tested: rating curves, linear interpolation, and the ratio method. The reliability of mean SPM concentrations improved with increasing sampling frequency, but even weekly sampling gave error rates as high as 70% in seasons with elevated sediment loads. Load estimates varied considerably depending on both the sampling frequency and the calculation method used. None of the methods provided consistently good results, but the lowest error rate was achieved when using the rating curve on data from fortnightly sampling and additional sampling during floods. Sampling at monthly intervals gave the highest error rates and cannot be recommended for any of the calculation methods applied here. SPM concentrations were correlated (r(2)>0.5) with arsenic, lead, nickel, orthophosphate, and total phosphorus in the Numedalslågen River. Therefore, the current findings may also have implications for substances other than SPM. The discussion considers examples from actual use of infrequently collected data, and it is advised that managers account for uncertainties in both concentration means and load estimates when assessing the state of a water body or planning mitigation measures.

Integrated tool for risk assessment in agricultural management of soil erosion and losses of phosphorus and nitrogen.

In recent years, increased attention has been focused on models for risk assessment of source areas in agricultural landscapes. Among the simplest of such models are index tools, which have been developed particularly for phosphorus (P) and to some extent nitrogen (N). However, only a few studies have considered the development of an integrated management strategy that includes erosion and losses of both P and N. Accordingly, the major objective of this study was to initiate the development of an integrated risk assessment tool, consisting of indices for erosion, P and N. The strategy used to create the integrated tool was based on the assumption that all input data at field scale should be readily available either from ordinary agricultural statistics or from the farmer. The results from using the indices in a pilot case study catchment illustrated that losses of P and N had often different critical source areas. The P index was highest for fields with manure application and/or high soil P status or with autumn ploughing, and the N index was highest for fields with excessive N application. The integrated risk was greatest for areas with manure application and some areas with a high erosion risk in combination with high nutrient application rate. Additionally, four different management options were assessed: (1) reduced fertilisation, (2) catch crops, (3) autumn ploughing, and (4) no autumn ploughing. The results verified that reduced nutrient application and stubble during autumn and winter led to the largest decrease in index values, and it was also apparent that management changes in high-risk areas had the greatest impact on the indices. Overall, our findings indicate that the present integrated risk assessment tool with readily available input data can be used to rank farm fields according to risk of soil erosion and losses of P and N.

Temporal and spatial variation of nutrient levels in the Nemunas River (Lithuania and Belarus).

There are discordant results on trends in nutrient river water quality from the economical transition countries in Europe. The present study assessed the impact of these economical changes on the load and concentration at 17 monitoring stations along the Nemunas River and its major tributaries (Lithuania and Belarus). Three time periods were evaluated: the Soviet rule command system period 1986-1991, the transfer to market economy period 1992-1996 and the post reform period 1997-2002. The most surprising result in this study, was the increased area-specific load of NO(3)-N from the first to the third period at almost all the sampling sites. The increase was particularly large (43-78%) at the sites in the Lithuanian part of the river. The corresponding load increase in the Belarussian part of the river was only 1-15%. The statistical analyses of concentration data confirm the strong upward NO(3)-N trend at the Nemunas mouth and at 5 of the 6 tributaries in the lower part of Nemunas. Temporal and spatial analysis of nitrates transport in the Nemunas River and its main tributaries revealed that nitrates mainly originate from agricultural areas. The upward trends were most likely an effect of ploughing of pastures and unbalanced crop fertilisation in combination with large storage and accumulation of soil-nitrogen during the Soviet period. On contrary to nitrate-N, the area-specific load of PO(4)-P decreased significantly from the first to the third period at all sites along the Nemunas River (31-86%). Seasonal (SMK) and Partial (PMK) Mann-Kendall tests on PO(4)-P concentrations also showed significant downward trend at 14 of 16 investigated sites. The decrease of PO(4)-P levels was attributed to the reduction of municipal and industrial point source emissions and to the decreased livestock numbers. The NH(4)-N load showed the same pattern as PO(4)-P. At the river mouth the load was 90 kg km(-2) yr(-1) during the first period compared to only 20-30 kg km(-2) yr(-1) in the third period. The trend test on NH(4)-N concentrations detected significant downward trends at 5 out of 16 sites. The declines were explained by decreased emissions from cities and large animal breeding farms. This study showed that trend analysis at multiple sites in a river basin is crucial for the understanding of the variability in time and space. Such analysis is also important for our interpretation of underlying sources and fluxes in a drainage basin over time. This is particularly important for compounds that have different source origin.

Effect of policy-induced measures on suspended sediments and total phosphorus concentrations from three Norwegian agricultural catchments.

In Norway, agricultural subsidies have, since the late 1980s, been targeted to reduce soil erosion, transfer of soil particles and phosphorus (P) losses. The subsidies led to, e.g., a fourfold increase in the area not ploughed from 1991 to 2001 and a reduced P fertiliser consumption by 60%, especially in areas with high livestock density. Moreover, in the late 1980s agricultural point sources of P from storage facilities of manure and fodder were reduced. In this paper, we evaluate the effect of these policy-induced measures and changed agricultural practices on suspended sediment (SS) and total P (TP) concentrations in three agricultural catchments (1, 3 and 87 km2). Results from the statistical trend analyses for the study period (14-17 years) showed weak, but statistically significant (p<0.05), downward trends in concentrations of TP and SS in the two streams with a high initial TP or SS concentration. In the stream with low initial concentrations of TP and SS, however, no statistically significant trends were shown. The stream with the highest initial concentration of SS showed a statistically significant downward trend in both TP and SS concentrations. The catchment with low initial concentration of SS and medium livestock density showed no detectable trends, while the catchment with high livestock density and low concentrations of SS in the stream showed a statistically significant downward trend in TP concentrations. The results from this study suggest that subsidies and mitigation measures can reduce concentrations of TP and SS in streamwater in highly polluted catchments, although the reduction is small compared to the variations between catchments.