Description: Highlights: • The impact of brine discharge on coastal food-web was modeled. • Stable isotope data validated the simulated trophic structure. • Simulated and observed spatial-temporal biomass trends were comparable. • Simulated outflow brine plumes had limited impact on the food-web. • Temperature had a greater negative impact on biomass than salinity. Abstract: Population growth and climate change have led to an increasing demand for freshwater, and subsequently to an exponential growth of the seawater desalination industry in which the number of reverse osmosis-based plants is constantly increasing. The purpose of this study was to examine the possible impact of brine discharge on the marine food-web by constructing and analyzing food-web models from two desalination plant environments located along the Israeli coastline. The models were constructed using the Ecopath and Ecosim with Ecospace modeling suite, and analyses of collected samples were used for calibration and validation. Additionally, we conducted a series of scenarios in order to evaluate the impact of increased salinity and temperature on the food-web. A comparison between model output and measured isotopic δ15N values yielded a good fit. In addition, Ecopath results illustrated the importance of the zooplankton groups both in terms of biomass and trophic level. Ecospace results indicated that most functional groups biomass decreased compared to the "no desalination" scenario. The results indicate that elevated temperature most likely has a greater effect than increased salinity on the food-web, and that there is a general decrease in functional groups biomass due to desalination.

Description: The aim of this work is to present the food web models developed using the Ecopath with Ecosim (EwE) software tool to describe structure and functioning of various European marine ecosystems (eastern, central and western Mediterranean Sea; Black Sea; Bay of Biscay, Celtic Sea and Iberian coast; Baltic Sea; North Sea; English Channel, Irish Sea and west Scottish Sea; and Norwegian and Barents Seas). A total of 195 Ecopath models based on 168 scientific publications, which report original, updated and modified versions, were reviewed. Seventy models included Ecosim temporal simulations while 28 implemented Ecospace spatiotemporal dynamics. Most of the models and publications referred to the western Mediterranean Sea followed by the English Channel, Irish Sea and west Scottish Sea sub-regions. In the Mediterranean Sea, the western region had the largest number of models and publications, followed by the central and eastern regions; similar trends were observed in previous literature reviews. Most models addressed ecosystem functioning and fisheries-related hypotheses while several investigated the impact of climate change, the presence of alien species, aquaculture, chemical pollution, infrastructure, and energy production. Model complexity (i.e., number of functional groups) increased over time. Main forcing factors considered to run spatial and temporal simulations were trophic interactions, fishery, and primary production. Average scores of ecosystem indicators derived from the Ecopath summary statistics were compared. Uncertainty was also investigated based on the use of the Ecosampler plug-in and the Monte Carlo routine; only one third of the reviewed publications incorporated uncertainty analysis. Only a limited number of the models included the use of the ECOIND plug-in which provides the user with quantitative output of ecological indicators. We assert that the EwE modelling approach is a successful tool which provides a quantitative framework to analyse the structure and dynamics of ecosystems, and to evaluate the potential impacts of different management scenarios.