Luca Palmeri

Quantifying nitrogen retention in surface flow wetlands for environmental planning at the landscape-scale

Surface flow wetlands are valued highly for their high nutrient retention potential and their unique biodiversity. At present, there are an increasing number of activities aimed at restoring these sites as multifunctional landscape entities. The success of wetland restoration is however clearly dependent on the site selection to achieve the specific restoration goals. This study first presents a tool to identify the most suitable areas for the restoration of surface flow wetlands for water quality improvement in a given catchment and secondly compares three different mathematical equations in order to quantify the effect of nitrogen retention when restoring the previously selected, most suitable wetland sites. For site selection, a score system was developed which is linked to a Geographical Information System. The score system combines information from a given catchment in eight data layers including soil substrate, actual land use, relief features, hierarchical drainage basin classification, river proximity and socio-economic factors. The score system was applied to a potential use situation in the Neuwuhrener Au watershed (40 km2) in northern Germany belonging to the Baltic Sea drainage basin. Three areas were identified as most suitable for the restoration of surface flow wetlands. Their potential effect on nitrogen retention was evaluated using three different equations: (I) a linear relation between wetland load and a wetland; (II) an exponential equation between wetland load and wetland area; and (III) an exponential equation between wetland load and hydraulic retention time. The linear approach calculates increasing wetland retention with increasing upstream catchment area and appears to overestimate nitrogen retention in wetlands located more downstream. The two exponential equations calculated nitrogen retention in the three wetlands in the same order of magnitude. The results from the siting procedure and the prediction of nitrogen removal rates are useful for decision makers in wetland planning to base their decision on best available data and knowledge. The model comparison allows the incorporation of uncertainty in the decision progress which is seen as a necessary requirement when quantifying biological processes in environmental planning.

Nutrient budgets for European seas: A measure of the effectiveness of nutrient reduction policies

Socio-economic development in Europe has exerted increasing pressure on the marine environment. Eutrophication, caused by nutrient enrichment, is evident in regions of all European seas. Its severity varies but has, in places, adversely impacted socio-economic activities. This paper aims to evaluate the effectiveness of recently adopted policies to reduce anthropogenic nutrient inputs to European seas. Nitrogen and phosphorus budgets were constructed for three different periods (prior to severe eutrophication, during severe eutrophication and contemporary) to capture changes in the relative importance of different nutrient sources in four European seas suffering from eutrophication (Baltic Proper, coastal North Sea, Northern Adriatic and North-Western Black Sea Shelf). Policy success is evident for point sources, notably for P in the Baltic and North Seas, but reduction of diffuse sources has been more problematic.

Long-term changes in community composition and life-history traits in a highly exploited basin (northern Adriatic Sea): the role of environment and anthropogenic pressures

The changes in a marine community in the northern Adriatic Sea were explored over a period of 65 years using landings data from a commercial fishing fleet, and the role of fishing pressure and environmental variations in driving these changes was investigated. A total of 40 taxonomic categories, including one or several species, were analysed, representing 93·7% of the total landings. From 1945 to 2010 a significant decrease in the evenness index was observed, indicating a trend towards landings dominated by fewer taxa. The composition of the landings showed a temporal shift during the 1980s; from 1945 to the 1980s a continuous, clear change in composition took place, probably driven by an increase in fishing pressure as well as riverine nutrient inputs. Since the 1980s, a different trend of changing composition emerged. Among the analysed predictors, fishing capacity, summer seawater temperature, inflow from the Po River (the major river of the northern Adriatic Sea) and nutrients were related to the changes in landings. In relation to life-history traits of the landed species, the community shifted from large, late-maturing species to more fecund, smaller and earlier-maturing species. A high fishing pressure is probably the major cause of these changes, possibly acting synergistically with environmental variations.

A GIS-Based Score System for Siting and Sizing of Created or Restored Wetlands: Two Case Studies

Water bodies are impacted by watershed loads in terms of nutrients and xenobiotics. This impact impairs the designated uses of the water body. Often preventive actions and end-of-pipe treatments do not reach the acceptable load to ensure the water quality standard in the water body. Wetlands are suitable tools for improving the self-purification capacity of a water system and can be used as a tool to reduce pollutant loads in a river network.This paper presents a methodology for the Siting and Sizing of created or restored wetlands at the watershed level, based on Geographical Information Systems (GIS) technique and estimations of wetland required area. The final outputs of the methodology are a Land Score System for Siting and a first rough estimation for the Sizing. The combination of these two elements is expected to be useful as a planning tool for watershed management and wetland planning.In order to assess the reliability of the procedure two very different case-studies are considered.

Steps toward a shared governance response for achieving Good Environmental Status in the Mediterranean Sea

The Mediterranean region is of fundamental importance to Europe given its strategic position. The responsibility for its overall ecosystem integrity is shared by European Union Member States (EU-MS) and other Mediterranean countries. A juxtaposition of overlapping governance instruments occurred recently in the region, with the implementation of both the Marine Strategy Framework Directive (MSFD) for EU-MS and the Ecosystem Approach Strategy (ECAP) for all Mediterranean countries, including EU-MS. Both MSFD and ECAP are structured around vision-driven processes to achieve Good Environmental Status and a Healthy Environment, respectively. These processes have clear ecosystem-based, integrated policy objectives to guarantee the preservation and integrity of Mediterranean marine ecosystem goods and services. However, adoption of these instruments, especially those related to the new EUMS directives on marine policy, could result in a governance gap in addition to the well-known economic gap between the EU and the non-EU political blocs. We identify two complementary requirements for effective implementation of both MSFD and ECAP that could work together to reduce this gap, to ensure a better alignment between MSFD and ECAP and better planning for stakeholder engagement. These are key issues for the future success of these instruments in a Mediterranean region where discrepancies between societal and ecological objectives may pose a challenge to these processes.

Impacts of Climate Change on Water Quality

In this chapter we present the result of two model exercises aiming at simulating the impact of climate change onto two classes of surface aquifers: lakes and rivers. Section 10.1 focuses on the impact of global warming on the thermal structure of two Italian South alpine lakes: Lake Como and Pusiano. Long term hydrodynamic simulations (1953–2050) were performed using the hydrodynamic model DYRESM (Dynamic Reservoir Simulation Model). DYRESM simulations were forced with downscaled regional climate scenarios undertaken within CIRCE. Our model simulations projected a yearly average temperature increase of 0.04°C year−1 for the period 1970–2000 and 0.03°C year−1 for the period 2001–2050 (A1b IPCC scenario). These results are in line with those detected in long term research studies carried out world-wide. This temperature increase is first responsible for a general increase of the water column stability and for a reduction of the mass transfer between deep and surface waters with direct implications on the oxygen and nutrient cycles. The magnitude of the temperature increase is also sufficient to impact on the growth of phytoplankton populations and it is likely one of the concurrent causes promoting the massive cyanobacteria blooms, recently detected in the two Italian case studies and in different lake environments in Europe. Section 10.2 approaches the problem of establishing a methodology to estimate the average yearly nutrient (phosphorus and nitrogen) river loads under present climate conditions and under the forcing of climate change. The case study is the Po River the largest hydrological basin in Italy and the third tributary of the Mediterranean semi-enclosed basin. The methodology developed in this study is based on a hierarchy of different numerical models which allowed to feed the MONERIS model (MOdeling Nutrient Emissions into River System) with the necessary meteorological and hydrological forcing. MONERIS was previously calibrated (1990–1995) and validated (1996–2000) under past conditions and then run under current conditions to define a control experiment (CE). Current nutrient loads have been estimated in 170,000 and 8,000 t year−1 respectively for nitrogen and phosphorus. Approximately 70% of the nitrogen load is from diffuse sources while 65% of the phosphorus load originates from point sources. Nutrient loads projections at 2100 (under different IPCC scenarios) allowed to estimate that both nitrogen and phosphorus loads are strictly dependent on the resident population which is responsible of a 61 and 41% increase respectively for nitrogen and phosphorus. Projected nutrient load variations were found to be negligible when holding the resident population constant. Finally the phosphorus load is markedly influenced by the efficiency of the waste water treatment plants (WWTPs).

A Comparative Analysis of Trophic Structure and Functioning in Large-Scale Mediterranean Marine Ecosystems

The Mediterranean is a sea rich with many kinds of diversity. It is a hotspot of marine biodiversity which covers many habitats and environmental conditions, and is surrounded by three continents characterized by different cultures and degrees of socio-economic development, whose coastal human activities exert multiple pressures on the marine environment. Yet, surprisingly, the diversity in the structure and functioning of Mediterranean marine ecosystems has not been analyzed rigorously, especially on large spatial scales. Such information are critical to implement an Ecosystem Approach to the management of the Mediterranean Sea. To fill this gap, a comparative analysis of the South Catalan, the Northern-Central Adriatic, the Northern Adriatic and the North Aegean Seas was performed. Trophic network models of the marine pelagic environment in each system were assembled with Ecopath software, based on published datasets. To facilitate the comparison, models were constructed with the same number and kind of trophic groups. Multiple indicators from ecological network analysis were calculated and consistently highlighted similarities and differences among Mediterranean pelagic food webs. Shared traits included the key role of intermediate-trophic level species, the low overall impact exerted by large predators, and inefficiencies in the exploitation of phytoplankton and detritus production giving rise to high export flows fuelling the benthic compartment. Primary productivity markedly influenced food web properties, but additional differences in the global structure of trophic flows emerged, highlighting a great ecosystem diversity. The systems could be ranked in a clear order of development and maturity (from high to low): South Catalan, Northern-Central Adriatic, North Aegean, Northern Adriatic Sea.

Phytoplankton dynamics in the Gulf of Aqaba (Eilat, Red Sea): a simulation study of mariculture effects.

The northern Gulf of Aqaba is an oligotrophic water body hosting valuable coral reefs. In the Gulf, phytoplankton dynamics are driven by an annual cycle of stratification and mixing. Superimposed on that fairly regular pattern was the establishment of a shallow-water fish-farm initiative that increased gradually until its activity was terminated in June 2008. Nutrient, water temperature, irradiation, phytoplankton data gathered in the area during the years 2007-2009, covering the peak of the fish-farm activity and its cessation, were analyzed by means of statistical analyses and ecological models of phytoplankton dynamics. Two datasets, one from an open water station and one next to the fish farms, were used. Results show that nutrient concentrations and, consequently, phytoplankton abundance and seasonal succession were radically altered by the pollution originating from the fish-farm in the sampling station closer to it, and also that the fish-farm might even have influenced the open water station.

Biopotentiality as an index of environmental compensation for composting plants

The Biopotentiality Index is a landscape ecology indicator, which can be used to estimate the latent energy of a given land and to assess the environmental impacts due to the loss of naturalness on a landscape scale. This indicator has been applied to estimate the effectiveness of the measures put in place to provide an environmental compensation for the revamping of a composting plant. These compensation measures are represented by a green belt with a minimum width of 25 m all around the plant, representing both a windbreak and a buffer zone, and by two wide wooded zones acting as core natural areas. This case-study shows that the compensation index could be used as a key tool in order to negotiate the acceptance of waste treatment plant with the population.

Deriving predicted no-effect concentrations (PNECs) for emerging contaminants in the river Po, Italy, using three approaches: Assessment factor, species sensitivity distribution and AQUATOX ecosystem modelling

Over the past decades, per- and polyfluoroalkyl substances (PFASs) found in environmental matrices worldwide have raised concerns due to their toxicity, ubiquity and persistence. A widespread pollution of groundwater and surface waters caused by PFASs in Northern Italy has been recently discovered, becoming a major environmental issue, also because the exact risk for humans and nature posed by this contamination is unclear. Here, the Po River in Northern Italy was selected as a study area to assess the ecological risk posed by perfluoroalkyl acids (PFAAs), a class of PFASs, considering the noticeable concentration of various PFAAs detected in the Po waters over the past years. Moreover, the Po has a large environmental and socio-economic importance: it is the largest Italian river and drains a densely inhabited, intensely cultivated and heavily industrialized watershed. Predicted no-effect concentrations (PNECs) were derived using two regulated methodologies, assessment factors (AFs) and species sensitivity distribution (SSD), which rely on published ecotoxicological laboratory tests. Results were compared to those of a novel methodology using the mechanistic ecosystem model AQUATOX to compute PNECs in an ecologically-sound manner, i.e. considering physical, chemical, biological and ecological processes in the river. The model was used to quantify how the biomasses of the modelled taxa in the river food web deviated from natural conditions due to varying inputs of the chemicals. PNEC for each chemical was defined as the lowest chemical concentration causing a non-negligible yearly biomass loss for a simulated taxon with respect to a control simulation. The investigated PFAAs were Perfluorooctanoic acid (PFOA) and Perfluorooctanesulfonic acid (PFOS) as long-chained compounds, and Perfluorobutanoic acid (PFBA) and Perfluorobutanesulfonic acid (PFBS) as short-chained homologues. Two emerging contaminants, Linear Alkylbenzene Sulfonate (LAS) and triclosan, were also studied to assess the performance of the three methodologies for chemicals whose ecotoxicology and environmental fate are well-studied. The most precautionary approach was the use of AFs generally followed by SSD and then AQUATOX, except for PFOS, for which AQUATOX yielded a much lower PNEC compared to the other approaches since, unlike the other two methodologies, it explicitly simulates sublethal toxicity and indirect ecological effects. Our findings highlight that neglecting the role of ecological processes when extrapolating from laboratory tests to ecosystems can result in under-protective threshold concentrations for chemicals. Ecosystem models can complement existing laboratory-based methodologies, and the use of multiple methods for deriving PNECs can help to clarify uncertainty in ecological risk estimates.