Ecosim Model Research Articles

Ecosystem model of Tasmanian waters explores impacts of climate-change induced changes in primary productivity

An Ecopath with Ecosim (EwE) model was developed that represents the marine shelf environment surrounding the island state of Tasmania (south of mainland Australia). Climate change scenarios representing a range of potential impacts (30% increase or decrease over a century) on marine primary productivity were investigated. Temperature changes and other impacts were not investigated. This analysis uncovered an asymmetric set of system responses. Modeled increases in primary productivity predict increases in the biomass of most groups, especially shallow filter-feeders (which includes oysters), fished macrozoobenthos which includes rock lobsters (Jasus edwardsii) and octopus. In contrast the group of unfished macrozoobenthos (sea stars, whelks) decreased their relative biomass as primary productivity increased. All modeled fisheries responded to varying primary production levels. The most responsive modeled fisheries were for flathead (Platycephalidae) and for those offshore. Of the groups of special conservation interest (marine mammals and seabirds) the most responsive was the dolphin group – though all responded.

An ecosystem approach for the assessment of fisheries impacts on marine top predators: the Bay of Biscay case study

Abstract Lassalle, G., Gascuel, D., Le Loc'h, F., Lobry, J., Pierce, G. J., Ridoux, V., Santos, M. B., Spitz, J., and Niquil, N. 2012. An ecosystem approach for the assessment of fisheries impacts on marine top predators: the Bay of Biscay case study. – ICES Journal of Marine Science, 69: 925–938. A number of marine mammal populations is currently threatened by their interactions with fisheries. The present study aimed to provide insights into the severity of potential impacts of operational and biological interactions between top predators and fisheries, in the Bay of Biscay region. Our approach was to modify an Ecopath with Ecosim (EwE) model describing the overall structure and function of the ecosystem by including landings and discards of exploited stocks and estimations of the bycatch of non-target compartments. Second, a set of ecological indices and a trophic level (TL)-based model (EcoTroph, ET) were derived from the EwE model. ET was used to simulate the effects of increasing fishing pressure on the ecosystem and, more particularly, on top predators. The Bay of Biscay was demonstrated to be not far from overexploitation at the current fishing rate, this phenomenon being particularly noticeable for the highest TLs. Within the toothed cetacean community, bottlenose dolphins appeared the most sensitive to resource depletion, whereas common dolphins and harbour porpoises were most impacted by their incidental captures in fishing gears. This study provides a methodological framework to assess the impacts of fisheries on ecosystems for which EwE, or other ecosystem models, already exist.

Fishery policy exploration in the Pearl River Estuary based on an Ecosim model

The Pearl River Estuary (PRE) is a tropical estuary that was an important fishery ground in the South China Sea, where many other fisheries have also experienced substantial declines in productivity. In this study, we develop an ecological model constructed by Ecopath with Ecosim (EwE) software to explore the consequences of different fishing policies on the management of the PRE ecosystem. Scenarios are examined that maximise the net profits from the fishing activities, the jobs provided by the fisheries and the measures of ecosystem status. Then the trade-offs due to the ecosystem-scale optimisation of fishery management policies are analysed. The results indicate that optimising short-term economic and social (employment) goals in the PRE creates a depletion of the top predators and losses of biodiversity. Alternatively, focusing on the structure of the ecosystem leads to a reduction in fishing effort for almost all fleets and a corresponding increase in the biomass of most fishes at the expense of reduced profits and jobs provided by the fisheries. An ideal policy compromise is found when equal weight placed on profits, jobs and ecosystem structure, which leads to an overall increase in profits, jobs/catch value, ecosystem maturity and biodiversity. The effects of changing weights placed on profits, jobs/catch value and ecosystem maturity on ecosystem indices are examined and the parameters of vulnerabilities and discount rates are also analysed in this paper.

Ecosystem models for management advice: An analysis of recreational and commercial fisheries policies in Baja California Sur, Mexico

Recreational fishing is a vital component of the tourism economy in Baja California Sur (BCS), Mexico, although several artisanal and industrial fisheries continue to operate in the region. The commercial long-liner fleet in particular is widely held to be responsible both for diminishing shark populations and declines in billfish through bycatch. Using available fisheries and ecosystem data, we develop an Ecopath with Ecosim (EwE) model to represent current ecosystem and fishing dynamics in BCS and explore the ecological and economic effects of specific fisheries policy measures. Results suggest that currently mandated bycatch limits for the longlining fleet will have little effect on marlin abundance in the area. In an overfished ecosystem, decreasing fishing effort can result in higher overall catches through population rebuilding. While perhaps ecologically justified, increases in the abundance of sharks, a top predator, can have negative effects on other valued species in the ecosystem. The effects of these trophic dynamics must not be overlooked, as they can negate or even reverse desired outcomes from fisheries management.

Integration of water quantity and quality in environmental flow assessment in wetlands

Hydrological regime is a driving factor in wetland ecosystems. Its excessive alteration will lead to severe degradation of wetlands. Assessment of environmental flows is essential for wetland protection, recovery, and restoration. In order to solve the existing problems of traditional methods, such as rarely considering water quality and ecosystem status, a new method was developed to assess the environmental flows of wetland that will reflect the synergistic effect of water quality and quantity on ecosystems. The proposed method was applied to the Baiyangdian wetland, the largest shallow lake and wetland complex in the North China Plain. The main steps are as follows: 1) Based on the maximum distance cluster results of water quality data and organism data, the Baiyangdian wetland was divided into five regions. The key species were distinguished by a series of simulated removal experiments using the Ecosim model. 2) Integrating the typical monthly average water level and the surface water quality standards of Classes III, IV, and V, 21 integrated scenarios were designed. Aquatox model was applied to analyze the response of phytoplankton, zooplankton, zoobenthos under different circumstances of water levels, NH3, NO3-, PO43-, BOD5 and other environmental factors, illustrating the temporal and spacial distribution of biomass, the status of structure and functions of ecosystem under the synergistic effect of water quality and quantity scenarios. 3) Based on the variation trend of assessment indicators such as total primary production/total respiration, total biomass/total production, biomass of zooplankton/biomass of phytoplankton in different regions, and the weighting factors for each region, finally we concluded that 6.70m can serve as the minimum ecological water level in Baiyangdian, and 7.19-9.55m can serve as the range of appropriate ecological water levels. These ecological water level results can guarantee the stability of the ecosystem structure and balance without having the reverse succession, which also has an ecological significance.

The Trophic Role of the Endangered Caribbean Manatee Trichechus manatus in an Estuary with low Abundance of Seagrass

Chetumal Bay is a refuge for the manatee, Trichechus manatus, a large and strictly herbivorous aquatic mammal. The ecosystem is notoriously poor in subaquatic vegetation, the main components of manatees’ diet. Due to the constant presence of manatees in the bay and their ability to consume large volumes of plant material, it is assumed that the species has a relevant trophic impact on the system. A mass–balance trophic model was designed to describe the flows of energy and matter in the bay, with the goal of assessing the role of manatees in the system. The system was aggregated in eight effective trophic levels. The biomass was intensely concentrated in the detritus, suggesting that the matter on the bottom sediment is the main regulator of the energy flow in the system. Primary producers comprised of detritus, mangrove, benthic autotrophs, and phytoplankton. The apex predators were dolphins and large piscivorous fishes. Manatees occupied the trophic level 2.0. Manatees were directly or indirectly impacted by autotrophs, mangrove, and detritus; but the competition between manatees and other groups was insignificant. In comparison to other ecosystems where manatees occur, Chetumal Bay (BCh) has the lowest relative biomass of seagrasses. Several ecological and behavioral mechanisms to compensate the lack of macrophytes biomass (or a combination of several) are suggested. Ecopath with Ecosim models are useful to describe the flow of energy and matter in the ecosystems. However, there are still critical gaps in the knowledge of BCh and its manatee population. It is difficult to assess the uncertainty associated with the estimates obtained; therefore, results should be interpreted with caution. Improving this preliminary model with robust local information on the Chetumal Bay ecology and its manatee population is recommended.

Potential impacts of climate change on Northeast Pacific marine foodwebs and fisheries

Abstract Ainsworth, C. H., Samhouri, J. F., Busch, D. S., Cheung, W. W. L., Dunne, J., and Okey, T. A. 2011. Potential impacts of climate change on Northeast Pacific marine foodwebs and fisheries. – ICES Journal of Marine Science, 68: 1217–1229. Although there has been considerable research on the impacts of individual changes in water temperature, carbonate chemistry, and other variables on species, cumulative impacts of these effects have rarely been studied. Here, we simulate changes in (i) primary productivity, (ii) species range shifts, (iii) zooplankton community size structure, (iv) ocean acidification, and (v) ocean deoxygenation both individually and together using five Ecopath with Ecosim models of the northeast Pacific Ocean. We used a standardized method to represent climate effects that relied on time-series forcing functions: annual multipliers of species productivity. We focused on changes in fisheries landings, biomass, and ecosystem characteristics (diversity and trophic indices). Fisheries landings generally declined in response to cumulative effects and often to a greater degree than would have been predicted based on individual climate effects, indicating possible synergies. Total biomass of fished and unfished functional groups displayed a decline, though unfished groups were affected less negatively. Some functional groups (e.g. pelagic and demersal invertebrates) were predicted to respond favourably under cumulative effects in some regions. The challenge of predicting climate change impacts must be met if we are to adapt and manage rapidly changing marine ecosystems in the 21st century.

Ecosystem structure and trophic analysis of Angolan fishery landings

Information on the mean trophic level of fishery landings in Angola and the output from a preliminary Ecopath with Ecosim (EwE) model were used to examine the dynamics of the Angolan marine ecosystem. Results were compared with the nearby Namibian and South African ecosystems, which share some of the exploited fish populations. The results show that: (i) The mean trophic level of Angola’s fish landings has not decreased over the years; (ii) There are significant correlations between the landings of Angola, Namibia and South Africa; (iii) The ecosystem attributes calculated by the EwE models for the three ecosystems were similar, and the main differences were related to the magnitude of flows and biomass; (iv) The similarity among ecosystem trends for Namibia, South Africa and Angola re-emphasizes the need to continue collaborative regional studies on the fish stocks and their ecosystems. To improve the Angolan model it is necessary to gain a better understanding of plankton dynamics because plankton are essential for Sardinella spp. An expanded analysis of the gut contents of the fish species occupying Angola’s coastline is also necessary.

Assessing biomass gains from marsh restoration in Delaware Bay using Ecopath with Ecosim

The Delaware Bay ecosystem has been the focus of extensive habitat restoration efforts to offset finfish losses due to mortality associated with power plant water intake. As a result, a 45 km 2 or a 3% increase in total marsh area was achieved by 1996–1997 through the restoration efforts of the Public Service Enterprise Group (PSEG). To quantify the impact of restoration efforts on system productivity, an Ecopath with Ecosim model was constructed that represented all major components of the ecosystem. The model consisted of 47 functional groups including: 27 fish species, 5 invertebrate groups, 4 multi-species benthic groups, 6 multi-species fish groups, 3 plankton groups, 1 shorebird group and 1 marine mammal group. Biomass, abundance, catch, and demographic data were obtained from the literature or from individual stock assessments conducted for principal ecosystem components. A base Ecosim model was fitted to time series of key species in the Bay representing the period 1966–2003. To access the gains from marsh restoration, model simulations reflecting no restoration were conducted to estimate the productivity that would have been lost if restoration efforts had not occurred. The results indicated that restoration increased total ecosystem biomass by 47.7 t km −2 year −1. Simulations indicated increased biomasses across a wide range of species including important forage and commercially important species. The marsh restoration also significantly impacted ecosystem structure increasing the ratio of production-to-respiration, increasing system path length and decreasing the ratio of production-to-biomass.

Qualitative Models to Complement Quantitative Ecosystem Models for the Analysis of Data-Limited Marine Ecosystems and Fisheries

Data-limitations increase the uncertainty of quantitative ecosystem models and have the potential to slow the progress of Ecosystem Based Fisheries Management. However, the most important finding of perturbation analysis for managers is arguably simple trends in community abundance. Qualitative models can be used to predict trends following perturbation and require only the signs (+, −, 0) of interactions between variables. To further increase the utility of qualitative models in ecosystem analysis, complementary alternative models, with differing uncertainties and assumptions can be used to assess the robustness of conclusions. Qualitative models and an Ecopath with Ecosim model were produced to investigate the inshore reef ecosystem of eastern Tasmania, Australia. The impact of fisheries, competition between fish species, and increasing urchin abundance on ecosystem dynamics were investigated. Qualitative models highlighted the need to decrease fisheries catches, the potential for cascading effects due to urchin grazing, and the capacity for large rock lobster to allow the regeneration of foliose algae. Ecopath with Ecosim produced consistent conclusions for the majority of qualitative predictions. Inconsistent conclusions were discussed with regard to differences in model calculation and behavior. The process undertaken in this study may allow progress in ecosystem analyses in data-poor situations, which may aid the development and implementation of Ecosystem Based Fisheries Management.

Effects of local fisheries and ocean productivity on the northeastern Ionian Sea ecosystem

To better understand the effects of fisheries and ocean productivity on the northeastern Ionian Sea we constructed an Ecopath with Ecosim model with 22 functional groups. Data on biomass, production/biomass, consumption/biomass, and diet for each group were estimated or extrapolated from the literature. Fisheries landings and discards were also included. Temporal trajectories were simulated using Ecosim. The model was fitted with time-series data for the most important groups from 1964 to 2006. Simulations highlighted a decline of top predators and of most of the commercial species since the late 1970s. The model shows that the decline of fish resources was mainly caused by an intensive fishing pressure that occurred in the area until the end of the 1990s and also by changes in primary production that impacted the trajectories of the main functional groups. In particular, simulated changes through time in PP impacted the abundance trends of all the commercial species, showing a cascade-up effect through the ecosystem. The application of Ecopath with Ecosim was a useful tool for understanding the trends of the main functional groups of the northeastern Ionian Sea. The model underlined that management actions are needed to restore and protect target species including marine mammals, pelagic and demersal fishes. In particular, measures to reduce overfishing, illegal fishing activities and to respect existing legislations are in need. Moreover, the adoption of marine protected areas could be an effective management measure to guarantee prey survival and to sustain marine predators.

Coupling and comparing a spatially- and temporally-detailed eutrophication model with an ecosystem network model: An initial application to Chesapeake Bay

Coastal waters are modeled for a variety of purposes including eutrophication remediation and fisheries management. Combining these two approaches provides insights which are not available from either approach independently. Coupling is confounded, however, by differences in model formulations and ''currencies.'' We present here an initial coupling of a spatially- and temporally-detailed eutrophication model, CE-QUAL-ICM, with a network fisheries model, Ecopath. We list commonalities between the models and present algorithms and software for the exchange of information. The models are applied to the central portion of Chesapeake Bay for a contemporary summer period. After comparison of the representations of Chesapeake Bay by the two models, an illustrative example one-way, off-line, coupling is presented. In an initial examination of a 20% increase in predation on phytoplankton by a small, highly-exploited fish (Atlantic menhaden, Brevoortia tyrannus), computed reduction in phytoplankton biomass is accompanied by increased production due to enhanced nutrient recycling. Minimal impact on the structure of the food web or on biomass of higher-trophic level organisms is computed. The algorithms and software can be adapted to alternate eutrophication models and Ecopath applications and provide the first, necessary, steps for subsequent coupling with the time-variable Ecosim model.

Changes in the trophic interactions and the community structure of Lake Taihu (China) ecosystem from the 1960s to 1990s

As the third largest freshwater lake in China, Lake Taihu has suffered from overfishing, eutrophication, and physical disturbance over the last several decades. Evaluating and quantifying changes in the ecosystem can help us better understand and develop hypotheses to explain the dynamics of the ecosystem. In this study, trophic interactions and community structure of commercial fisheries species of Lake Taihu ecosystem were analyzed and compared for three time periods (1961–1965, 1981–1987, and 1991–1995) using the Ecopath with Ecosim model with the aim of evaluating the changes in the population dynamics and ecosystem development mechanism spanning the period from the 1960s to 1990s. The results show that the biomass of large predators decreased over the three decades, while the biomass of small species increased. Increases in the P/B ratios and fishing mortality levels observed for species groups reveal rapidly intensifying fishery stress over the three decades. The fisheries operated at the highest trophic level during the 1980s, and there are some indications of “fishing down the food web” in this ecosystem between the 1980s and the 1990s. Drawing upon Odum’s theory of ecosystem maturity, the structured, web-like ecosystem of the 1960s developed into a highly mature system during the 1980s; yet, in the 1990s, this structure became less complex and the system’s maturity fell to its lowest observed level. During this period, the successional development of the system occurred in reverse.

Modeling the effects of fishery management and marine protected areas on the Beibu Gulf using spatial ecosystem simulation

The Gulf of Beibu, recognized as one of the traditional fishing grounds, is a center of rich biodiversity in the northern South China Sea. Based on the Beibu Gulf ecosystem constructed by the Ecopath and Ecosim model (in the late 1990s), we used Ecospace to evaluate the existing fishery management system and assess the potential of marine protected areas (MPAs) in the Beibu Gulf over a short (5-year), medium (10-year), and long-term (20-year) scenario. The results suggest that the current trawl closure and the midsummer moratorium system used in the Gulf fishery management approach appear to offer minimal benefits for stock recovery because of the high implementation and administrative costs; also, the biomass of valuable groups would decrease drastically with simulation time, and the large predator groups, such as the large demersal and pelagic fishes, would even be reduced to depletion in the long-term (20-year) simulation. Simulations of MPAs indicate that outcomes beneficial to all are possible but not guaranteed. Both ‘no-take’ MPAs, inshore closures (<30-m isobath) and offshore closures (common fishing zone) can drastically reduce fishing effort (between 20% and 30% reduction from 1999 levels), achieving much to avert the collapse of the fishery sector, especially for large-sized, high-value species. The magnitude of the biomass and the catches would obviously increase with simulation time. In a 20-year simulation, the total catches of all fishing gears would be doubled in the inshore closure simulation compared with that of offshore closure simulation with biomass recovery. The results suggest that, for purposes of fishery management in the Gulf, the inshore area within the 30-m isobath should be considered as ‘no-take’ MPAs; this may be an effective management tactic to conserve the ecosystem and to stop the decline in fisheries resources. Considering the complexity of ecosystem-based fishery management, an extension of the current work will incorporate the costs associated with restoration and monitoring efforts as well.

Database-driven models of the world's Large Marine Ecosystems

We present a new methodology for database-driven ecosystem model generation and apply the methodology to the world's 66 currently defined Large Marine Ecosystems. The method relies on a large number of spatial and temporal databases, including FishBase, SeaLifeBase, as well as several other databases developed notably as part of the Sea Around Us project. The models are formulated using the freely available Ecopath with Ecosim (EwE) modeling approach and software. We tune the models by fitting to available time series data, but recognize that the models represent only a first-generation of database-driven ecosystem models. We use the models to obtain a first estimate of fish biomass in the world's LMEs. The biggest hurdles at present to further model development and validation are insufficient time series trend information, and data on spatial fishing effort.

Mass-balanced trophic and loop models of complex benthic systems in northern Chile (SE Pacific) to improve sustainable interventions: a comparative analysis

The capacity to withstand perturbations and the propagation of direct and indirect effects of harvesting were explored in seagrass and sand–gravel subtidal subsystems of northern Chile using Ecopath II, Ecosim and Loop Analysis theoretical frameworks. The relative Ascendancy and Redundancy from Ecopath II and Ecosim models and the holistic stability measure (Fn) given by Loop Analysis, all suggest that the sand–gravel subsystem is the more resistant and its fishery more sustainable. This outcome is relevant since the theoretical frameworks used are based on different assumptions but arrive at similar conclusions. If the fishery is included in the qualitative ecological models, which were found locally stable only when the fishery is self-controlled. While this conclusion is not new, its relevance here is that it emerges from qualitative multispecies modelling (Loop Analysis). Based on our model predictions, the biomass removal of the sea star Meyenaster gelatinosus would increase the standing stock of the commercial scallop Argopecten purpuratus only in the seagrass habitat, whereas the same man-made intervention may have an opposite effect in the sand–gravel habitat. We recommend to enunciate holistic models based on the theoretical framework used in the current work, which explore the reality from different perspectives assuming different givens. Based on these holistic explorations alternative and complementary management scenarios could be designed.

Exploring optimal fishing scenarios for the multispecies artisanal fisheries of Eritrea using a trophic model

This study represents the first attempt to assess the potential for fisheries in the artisanal Red Sea reef fisheries of Eritrea in an ecosystem context. We used an Ecopath with Ecosim model to integrate known aspects of the ecosystem and its inhabitants into a single framework, with the aim to gain a better insight into the structure and functioning of the ecosystem and to assess the impacts of fishing in these data-limited fisheries. Model outputs indicate that most of the primary productivity in the system is recycled through a detritus-based food web, implying a bottom-up energy flow control. Ecotrophic efficiencies were nevertheless higher at higher trophic levels, suggesting that top-down control mechanisms are also ecologically important. Notwithstanding a high degree of primary productivity, the fishery yields estimated for the coral reef ecosystem were relatively low, apparently because of lower ecotrophic efficiencies at the lower trophic levels. A retrospective simulation of trends in these fisheries using Ecosim showed that, given the existing fishing intensity as suggested by official statistics (0.114 tonnes km −2 year −1), fishery-induced decline in abundance and yield of reef-associated demersals of the magnitude (ca. 25%) suggested by a previous study are unlikely. However, the decline in yield observed in these fisheries could be reproduced in the simulation when the existing fishing level was assumed to be five-fold the official estimate, as suggested by anecdotal evidence on unreported catches. The simulation results show that an optimal fishing strategy could be achieved through a slight reduction in the annual catch of reef-associated fish (to 0.32 tonnes km −2 year −1) and an increase in the capture of near-reef pelagics and large pelagics (to 0.19 and 0.39 tonnes km −2 year −1, respectively) from the putative levels. We explored optimal fishing scenarios in view of both direct effects of fishing on target species and indirect effects of fishing on non-target organisms. Finally, this study demonstrates that, even if modeling is no substitute for rigorous assessment of individual fish stocks with more detailed data, it could improve our understanding of the impacts of fishing on the structure and functioning of coral reef ecosystems in such newly developing fisheries, particularly on groups that would otherwise be difficult to monitor.

The effect of a crab predator (Cancer porteri) on secondary producers versus ecological model predictions in Tongoy Bay (south‐east Pacific coast): implications for management and fisheries

Abstract The present study compares the propagation of effects observed as a response to changes in the abundance of a top predator (top‐down cascading effect) in a benthic community within the south‐east Pacific upwelling ecosystem of northern Chile, with predictions derived from quantitative and qualitative multispecific models. Results with Loop Analysis achieved 71.4% of predictive certainty; indicating that this technique is useful for assessment of the effects of human intervention related to the mud‐bottom ecosystem tested. On the other hand, Ecosim using bottom‐up flow control mechanism achieved only 14.3% certainty. In an intermediate range, predictions obtained using the Mixed Trophic Impacts and Ecosim models using top‐down, mixed and flow control mechanisms estimated by the program, achieved 57.1% certainty. The results obtained have important implications for the management of communities and ecosystems since human interventions can be studied using holistic models with an end result of evaluating the eventual changes that they propagate. Copyright © 2007 John Wiley &amp; Sons, Ltd.

Oceans and Coastal Tourism: Integrating Tourism into Bioeconomic Models

Models of resource sustainability and exploitation have developed as an important management tool for both scientific debate and policy development. Most models are developed to reflect a single resource such as oil, or a single environment such as a river. Bioeconomic modeling of ocean environments has become a major tool for the evaluation and management of fish stocks and fisheries, but rarely incorporates an interrelationship with other economic activities. This article extends a bioeconomic fisheries model by incorporating the economic and physical interrelationships with coastal and marine tourism. Tourists are classified into three basic types (general, water sports, and recreational fishing) representing different interactions with the marine environment, fishing, and coastal communities; the outcome is an assessment of the impact and economic value of tourism within these communities where there is, or has been, some dependence on fishing for their livelihood. A mixture of ECOSIM and STELLA modeling is used to show that certain types of tourism interact most positively with smaller scale fisheries in such a way as to compensate, at a community level, for their inherently "lower efficiency" and higher cost basis than large-scale fishing. It is also demonstrated that it is possible to incorporate an analysis of common pool resource competition between user groups within this model (tourists' and fisheries' use of marine resources) in such a way as to establish a viable numéraire for a tourism user-pays policy. The research is of particular interest in communities or regions where the decline of fish stocks or other problems with fisheries have resulted in regeneration policies (such as PESCA in the EU) where tourism may be viewed as an alternative or complementary economic activity. The concepts of the model can apply equally to, for example, rural tourism in a land-based bioeconomy.

Can ECOPATH with ECOSIM enhance models of radionuclide flows in food webs? – an example for 14C in a coastal food web in the Baltic Sea

In this study it was evaluated whether the ECOPATH with ECOSIM software could be used as a platform to facilitate the construction of models and study of transport and accumulation of radionuclides in aquatic food webs. The evaluation was based upon a food web model of carbon (C) and carbon-14 ( 14C) flow for a coastal area in the Baltic Sea, the ECOPATH, the ECOSIM and the ECOTRACE models. The original carbon flows and assumptions were easily incorporated into the ECOPATH and ECOSIM modelling environment. The new model was also well suited to drive a 14C flow model (ECOTRACE) for each of the organisms included. ECOTRACE estimated steady-state concentrations of 14C that were between 73 and 142% of the original flows. The results clearly show that there is great potential for a successful development of this approach for integrating scientific knowledge about food webs and radioecological models for aquatic systems.