Tuomo Saloranta

A conceptual framework for identifying the need and role of models in the implementation of the water framework directive

Abstract The new European Water Framework Directive (WFD) aims at improving water quality using an integrated approach to implement necessary societal and technical measures. Successful implementation of the WFD requires appropriate mathematical models and other tools to manage different phases of the planning procedure and to support decision making in various steps of the implementation process. Design, development, testing and use of these tools call for the development of a conceptual framework, which provides a basis to assure that proper tools will be available and selected for defined purposes. We developed the well‐known DPSIR framework to fit better to the WFD implementation process, and to this framework we identified which types of models are needed in different consecutive steps of the process. The framework, which we call the DPCER framework and which links to different model types, (i) is dynamic, (ii) indicates cause‐consequence relationships, (iii) integrates human and natural science, and (iv) is policy relevant. Its purpose is to bring the potential model applications into a wider perspective and lay a foundations for the selection of models and other tools within the identified three different phases of WFD implementation.

Interannual variability in the hydrography of Atlantic water northwest of Svalbard

Using data from 1910 to 1997, we study the mean structure as well as the interannual variability in the autumn hydrography of the part of the West Spitsbergen Current (WSC) confined over the upper continental slope and of its continuation, the Svalbard branch. This is known to provide a major pathway for warm and saline Atlantic water to the Arctic Ocean. We focus our study on the area northwest of Svalbard, around 80°N. The time series of subsurface hydrography (100–300 m layer) show interannual variations which are, in the 1980s and 1990s, quite coherent with hydrographic time series obtained upstream in the WSC around 76°N as well as with variations in the large-scale atmospheric patterns, as indicated by the North Atlantic Oscillation (NAO) index. However, in the 1970s, the coherence is poorer. Our results suggest that it may be important to focus on the narrow domain of the part of the WSC confined over the upper continental slope in order to get consistent estimates of the Arctic Ocean inflow signal in the Fram Strait. The warming in this inflow signal (in 1970–1996) does not seem to have been as strong as previously suggested.

Use of Life Cycle Assessments To Evaluate the Environmental Footprint of Contaminated Sediment Remediation

Ecological and human risks often drive the selection of remedial alternatives for contaminated sediments. Traditional human and ecological risk assessment (HERA) includes assessing risk for benthic organisms and aquatic fauna associated with exposure to contaminated sediments before and after remediation as well as risk for human exposure but does not consider the environmental footprint associated with implementing remedial alternatives. Assessment of environmental effects over the whole life cycle (i.e., Life Cycle Assessment, LCA) could complement HERA and help in selecting the most appropriate sediment management alternative. Even though LCA has been developed and applied in multiple environmental management cases, applications to contaminated sediments and marine ecosystems are in general less frequent. This paper implements LCA methodology for the case of the polychlorinated dibenzo-p-dioxins and -furans (PCDD/F)-contaminated Grenland fjord in Norway. LCA was applied to investigate the environmental footprint of different active and passive thin-layer capping alternatives as compared to natural recovery. The results showed that capping was preferable to natural recovery when analysis is limited to effects related to the site contamination. Incorporation of impacts related to the use of resources and energy during the implementation of a thin layer cap increase the environmental footprint by over 1 order of magnitude, making capping inferior to the natural recovery alternative. Use of biomass-derived activated carbon, where carbon dioxide is sequestered during the production process, reduces the overall environmental impact to that of natural recovery. The results from this study show that LCA may be a valuable tool for assessing the environmental footprint of sediment remediation projects and for sustainable sediment management.

Simulating climate change‐induced alterations in bioaccumulation of organic contaminants in an Arctic marine food web

Climate change is expected to alter environmental distribution of contaminants and their bioaccumulation due to changes in transport, partitioning, carbon pathways, and bioaccumulation process rates. Magnitude and direction of these changes and resulting overall bioaccumulation in food webs is currently not known. The present study investigates and quantifies the effect of climate change in terms of increased temperature and primary production (i.e., concentrations of particulate organic carbon, C(POC)), on bioaccumulation of organic contaminants in biota at various trophic levels. The present study covers only parts of the contaminant behavior that is influenced by climate change, and it was assumed that there were no changes in food web structure and in total air and water concentrations of organic contaminants. Therefore, other climate change-induced effects on net bioaccumulation, such as altered contaminant transport and food web structure, should be addressed in future studies. To determine the effect of climate change, a bioaccumulation model was used on the pelagic marine food web of the Arctic, where climate change is expected to occur fastest and to the largest magnitude. The effect of climate change on model parameters and processes, and on net bioaccumulation, were quantified for three modeling substances (gamma-hexachlorocyclohexane [HCH], polychlorinated biphenyl [PCB]-52, and PCB-153) for two possible climate scenarios. In conclusion, increased temperature and C(POC) reduced the overall bioaccumulation of organic contaminants in the Arctic marine food web, with the largest change being for PCB-52 and PCB-153. Reduced bioavailability, due to increased C(POC), was the most influential parameter for the less water soluble compounds. Increase in temperature resulted in an overall reduction in net bioaccumulation.

Flows of dioxins and furans in coastal food webs: inverse modeling, sensitivity analysis, and applications of linear system theory.

Rate constant bioaccumulation models are applied to simulate the flow of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the coastal marine food web of Frierfjorden, a contaminated fjord in southern Norway. We apply two different ways to parameterize the rate constants in the model, global sensitivity analysis of the models using Extended Fourier Amplitude Sensitivity Test (Extended FAST) method, as well as results from general linear system theory, in order to obtain a more thorough insight to the systems behavior and to the flow pathways of the PCDD/Fs. We calibrate our models against observed body concentrations of PCDD/Fs in the food web of Frierfjorden. Differences between the predictions from the two models (using the same forcing and parameter values) are of the same magnitude as their individual deviations from observations, and the models can be said to perform about equally well in our case. Sensitivity analysis indicates that the success or failure of the models in predicting the PCDD/F concentrations in the food web organisms highly depends on the adequate estimation of the truly dissolved concentrations in water and sediment pore water. We discuss the pros and cons of such models in understanding and estimating the present and future concentrations and bioaccumulation of persistent organic pollutants in aquatic food webs.

Simulating the uncertain effect of active carbon capping of a dioxin-polluted Norwegian fjord.

Process-based multimedia models are frequently used to simulate the long-term impacts of pollutants and to evaluate potential remediation actions that can be put in place to improve or manage polluted marine environments. Many such models are detailed enough to encapsulate the different scales and processes relevant for various contaminants, yet still are tractable enough for analysis through established methods for uncertainty assessment. Inclusion and quantification of the uncertainty associated with local efficacy of remediation actions is of importance when the desired outcome in terms of human health concerns or environmental classification shows a nonlinear relationship with remediation effort. We present an updated fugacity-based environmental fate model set up to simulate the historical fate of polychlorinated dibenzo-p-dioxins and dibenzo-furans (PCDD/Fs) in the Grenland fjords, in Norway. The model is parameterized using Bayesian inference and is then used to simulate the effect of capping parts of the polluted sediments with active carbon. Great care is taken in quantifying the uncertainty regarding the efficacy of the activated carbon cap to reduce the leaching of contaminants from the sediments. The model predicts that by capping selected parts of the fjord, biota will be classified as moderately polluted approximately a decade earlier than a natural remediation scenario. Our approach also illustrates the importance of incorporating uncertainty in local remediation efforts, as the biotic concentrations scale nonlinearly with remediation effort.