End-To-End Modeling Reveals Species-Specific Effects of Large-Scale Coastal Restoration On Living Resources Facing Climate Change

Coastal erosion and wetland loss are affecting Louisiana to such an extent that the loss of land between 1932 and 2016 was close to 5,000 km2. To mitigate this decline, coastal protection and restoration projects are being planned and implemented by the State of Louisiana, United States. The Louisiana Coastal Master Plan (CMP) is an adaptive management approach that provides a suite of projects that are predicted to build or maintain land and protect coastal communities. Restoring the coast with this 50-year large-scale restoration and risk reduction plan has the potential to change the biomass and distribution of economically and ecologically important fisheries species in this region. However, not restoring the coast may have negative impacts on these species due to the loss of habitat. This research uses an ecosystem model to evaluate the effects of plan implementation versus a future without action (FWOA) on the biomass and distribution of fisheries species in the estuaries over 50 years of model simulations. By simulating effects using a spatially-explicit ecosystem model, not only can the changes in biomass in response to plan implementation be evaluated, but also the distribution of species in response to the planned restoration and risk reducation projects. Simulations are performed under two relative sea level rise (SLR) scenarios to understand the effects of climate change on project performance and subsequent fisheries species biomass and distribution. Simulation output of eight economically important fisheries species shows that the plan mostly results in increases in species biomass, but that the outcomes are species-specific and basin-specific. The SLR scenarios highly affects the amount of wetland habitat maintained after 50 years (with higher levels of wetland loss under increased SLR) and, subsequently, the biomass of species depending on that habitat. Species distribution results can be used to identify expected changes for specific species on a regional basis. By making this type of information available to resource managers, precautionary measures of ecosystem management and adaptation can be implemented

A century of fish biomass decline in the ocean

Contribution to the Theme Section ‘Trophodynamics in marine ecology’.-- 12 pages, 7 figures, 3 tables, supplementary material https://doi.org/10.3354/meps10946We performed a global assessment of how fish biomass has changed over the last 100 yr, applying a previously developed methodology using ecological modeling. Our assessment built on more than 200 food web models representing marine ecosystems throughout the world covering the period from 1880 to 2007. All models were constructed based on the same approach, and have been previously documented. We spatially and temporally distributed fish biomasses delivered by these models based on fish habitat preferences, ecology, and feeding conditions. From these distributions, we extracted over 68000 estimates of biomass (for predatory and prey fishes separately, including trophic level of 3.5 or higher, and trophic level between 2.0 and 3.0, respectively), and predicted spatial-temporal trends in fish biomass using multiple regression. Our results predicted that the biomass of predatory fish in the world oceans has declined by twothirds over the last 100 yr. This decline is accelerating, with 54% occurring in the last 40 yr. Results also showed that the biomass of prey fish has increased over the last 100 yr, likely as a consequence of predation release. These findings allowed us to predict that there will be fish in the future ocean, but the composition of fish assemblages will be very different from current ones, with small prey fish dominating. Our results show that the trophic structure of marine ecosystems has changed at a global scale, in a manner consistent with fishing down marine food webs. © Inter-Research 2014This is a contribution from Sea Around Us, a scientific cooperation between the University of British Columbia (UBC) and the Pew Charitable trust. V.C. acknowledges support from the Natural Sciences and Engineering Research Council of Canada. M.C. was partially funded by the EC Marie Curie Career Integration Grant Fellowships to the BIOWEB project and the Spanish National Program Ramon y Cajal.Peer Reviewe

Modelling marine trophic transfer of radiocarbon (14C) from a nuclear facility

Sellafield marine discharges of 14C are the largest contributor to the global collective dose from the nuclear fuel industry. As such, it is important to understand the fate of these discharges beyond the limitations and scope of empirical analytical investigations for this highly mobile radioactive contaminant. Ecopath with Ecosim (EwE) is widely used to model anthropogenic impacts on ecosystems, such as fishing, although very few EwE studies have modelled the fate of bioavailable contaminants. This work presents, for the first time, a spatial-temporal 14C model utilising recent developments in EwE software to predict the ecological fate of anthropogenic 14C in the marine environment. The model predicted observed trends in 14C activities between different species and through time. It also provided evidence for the integration of Sellafield 14C in species at higher trophic levels through time

Fish biomass in the world ocean: a century of decline

19 pages, 6 figures, 4 tablesWill there be fish in the ocean in 2050? To address this question, we made a data‐rich global assessment of how fish biomass has changed over the last hundred years. We built on more than 200 ecosystem models representing marine ecosystems throughout the world covering the period from 1880 to 2007, and all constructed based on the same approach. We used spatial modeling to distribute biomasses based on habitat preferences, ecology, and feeding conditions. We extracted over 68,000 estimates of fish biomass (for predatory and prey fishes, separately) distributed over time and space, and used multiple regression to predict biomass distributions. The regressions were highly significant and predict that the biomass of predatory fish in the world oceans has declined by two‐thirds over the last hundred years. This decline is accelerating, with 54% having taken place in the last 40 years. We also found that the biomass of prey fish has more than doubled over the last hundred years, likely as a consequence of predation release. Jointly, these findings allow us to predict that there will be fish in the ocean in 2050, but they will be mainly of small prey fish. Our study also addresses the controversy whether ‘fishing down the food web’ is a phenomenon actually occurring in nature or a sampling artifact due to catches not representing relative abundances in ecosystems. Our study strongly indicates that the impact of fisheries has caused fishing down the food web of ecosystem resources at the global levelThis is a contribution from the Sea Around Us project, a scientific cooperation between the University of British Columbia and the Pew Environment Group. VC further acknowledges support from the Canadian National Science and Engineering Research Council, and from the Nippon Foundation and UBC joint program, Nereus – Predicting the Future Ocean. This is Nereus Contribution No. 1Peer reviewe

Advances in spatial-temporal food web modelling with Ecospace

Integrated Marine Biogeochemistry and Ecosystem Research Open Science Conference (IMBER OSC 2014), Future Oceans, Research for marine sustainability: multiple stressors, drivers, challenges and solutions, 23-27 June 2014, Bergen, NorwayPeer Reviewe

Representing Variable Habitat Quality in a Spatial Food Web Model

Conference and workshops Ecopath 30 years – Modelling ecosystem dynamics: beyond boundaries with EwE, 4-14 November 2014, Barcelona, Spain.-- 2 pages, 1 figureWhy are marine species where they are? The scientific community is faced with an urgent need to understand aquatic ecosystem dynamics in the context of global change. This requires development of scientific tools with the capability to predict how biodiversity, natural resources, and ecosystem services will change in response to stressors such as climate change and further expansion of fishingMC was funded by the European Commission through the Marie Curie Career Integration Grant Fellowships to the BIOWEB project and the Spanish National Program Ramon y Cajal. This study forms a contribution to the Spanish Research project ECOTRANS. VC acknowledges support from the Natural Sciences and Engineering Research Council of CanadaPeer Reviewe

Representing Variable Habitat Quality in a Spatial Food Web Model

16 pages, 8 figures, 1 tableWhy are marine species where they are? The scientific community is faced with an urgent need to understand aquatic ecosystem dynamics in the context of global change. This requires development of scientific tools with the capability to predict how biodiversity, natural resources, and ecosystem services will change in response to stressors such as climate change and further expansion of fishing. Species distribution models and ecosystem models are two methodologies that are being developed to further this understanding. To date, these methodologies offer limited capabilities to work jointly to produce integrated assessments that take both food web dynamics and spatial-temporal environmental variability into account. We here present a new habitat capacity model as an implementation of the spatial-temporal model Ecospace of the Ecopath with Ecosim approach. The new model offers the ability to drive foraging capacity of species from the cumulative impacts of multiple physical, oceanographic, and environmental factors such as depth, bottom type, temperature, salinity, oxygen concentrations, and so on. We use a simulation modeling procedure to evaluate sampling characteristics of the new habitat capacity model. This development bridges the gap between envelope environmental models and classic ecosystem food web models, progressing toward the ability to predict changes in marine ecosystems under scenarios of global change and explicitly taking food web direct and indirect interactions into account. © 2014, Springer Science+Business Media New YorkMC was funded by the European Commission through the Marie Curie Career Integration Grant Fellowships to the BIOWEB project and the Spanish National Program Ramon y Cajal. This study forms a contribution to the Spanish Research project ECOTRANS. VC acknowledges support from the Natural Sciences and Engineering Research Council of CanadaPeer Reviewe

Using Ecosystem Modeling to Evaluate Trade-Offs In Coastal Management: Effects of Large-Scale River Diversions On Fish and Fisheries

A coupled ecosystem modeling approach was used to evaluate how select combinations of large-scale river diversions in the lower Mississippi River Deltaic Plain may affect the distribution, biomass, and landings of fish and shellfish over decades relative to a future without action. These river diversions are controlled openings in the riverbank of the Mississippi River designed to reintroduce sediment, water, and nutrients into hydrologically isolated coastal wetlands in order to mitigate wetland loss. We developed a spatial ecosystem model using Ecopath with Ecosim (EwE) software, and prepared it to receive output from a Delft3D hydrodynamic model coupled to primary production models. The Delft3D model provided environmental drivers including salinity, temperature, Chl a, total suspended solids, and change in wetland cover as a result of simulated river diversions over decadal model runs. Driver output was averaged either daily, monthly, or annually depending on the parameter. A novel oyster-specific subroutine is introduced in this paper to incorporate information at daily intervals in Ecospace, while Ecospace runs on a monthly time step. The ecosystem model simulates biomass and distribution of fish and shellfish species, and landings of targeted fisheries species, as a result of environmental changes projected for a preliminary set of management scenarios designed to evaluate and screen select combinations of river diversions. Abundant local field samples and landings data allowed for model calibration and validation. The results of simulations indicate that inflow of Mississippi River water in estuaries may cause local shifts in species assemblages. These changes were in some cases direct effects of decreased salinity, such as locally reduced Spotted Seatrout biomass. Changes in some other species in the affected areas resulted from indirect effects; for example, reduced Chl a (as a result of increased TSS) resulted in near-field reductions of Gulf Menhaden. The simulations also showed that local biomass reductions were mostly the result of redistribution, since the scenario with the proposed diversions open had minimal impact on the total biomass or landings of species simulated in the Mississippi River Delta as compared to a future without action. The model and its output were used as a decision support tool to help evaluate and compare alternative management actions. The results of this study played a role in the decision by the Coastal Protection and Restoration Authority to prioritize moving forward to conduct more detailed analyses through engineering and design of the two middle diversions but not the two lower diversions that were tested in this study

Bridging the gap between ecosystem modelling tools and geographic information systems: driving a food web model with external spatial-temporal data

Conference and workshops Ecopath 30 years – Modelling ecosystem dynamics: beyond boundaries with EwE, 4-14 November 2014, Barcelona, Spain.-- 2 pages, 2 figuresIt is becoming clear that climate change and human activities will have notable impacts on marine ecosystems in the future, but the extent is poorly understood. Research is challenged by the limitations of present-day ecosystem models to address the interrelated spatial dynamics between climate, ocean chemistry, marine food webs, and human systemsPeer Reviewe

Bridging the gap between ecosystem modeling tools and geographic information systems: Driving a food web model with external spatial-temporal data

13 pages, 13 figuresResearch toward the impacts of climate change and human activities on marine ecosystems is challenged by the limitations of present-day ecosystem models to address the interrelated spatial dynamics between climate, ocean chemistry, marine food webs, and human systems. The work presented here, the spatial–temporal data framework, is part of a larger study, the NF-UBC Nereus Program, to develop a new approach to model interoperability for closing the gap between marine ecosystem modeling tools via geographic information systems (GIS) technology. The approach we present simplifies interdisciplinary model interoperability by separating technical and scientific challenges into a flexible and modular software approach. To illustrate capabilities of the new framework, we use a remote-sensing derived spatial and temporal time series to drive the primary production dynamics in an existing food web model of the North-Central Adriatic using the Ecospace module of the Ecopath with Ecosim approach. In general, the predictive capabilities of the food web model to hind-cast ecosystem dynamics are enhanced when applying the new framework by better reflecting observed species population trends and distributions. Results show that changes at the phytoplankton level due to changes in primary production are realistically reproduced and cascade up the pelagic food web. The dynamics of zooplankton and small and large pelagic fish are impacted. Highly exploited demersal species such as European hake do, however, not show clear signs of cascading. This may be due to the high fishing pressure on this species and the resulting strong historical decline in the area. In general, the development of the new framework offers ecosystem modelers with unprecedented capabilities to include spatial–temporal time series into food web analysis with a minimal set of required steps. It is a promising step toward integrating species distribution models and food web dynamics, and future implementations of interdisciplinary model interoperabilityAcknowledgements JS, JB and VC participated through the Nippon NF-UBC NereusProgram, a collaborative initiative conducted by the Nippon Foundation, the University of British Columbia, and five additional partners, aimed at contributing to the global establishment of sustainable fisheries. Support through the Channel Integrated Approach for Marine Management (CHARM) III project, through the University of Greenwich, in part helped develop the spatial temporal data framework. MC was funded by the European Commission through the Marie Curie Career Integration Grant Fellowships to the BIOWEB project and the Spanish National Program Ramon y Cajal. VC also acknowledges support from the Canadian National Science and Engineering Research Council. We would like to thankthe Ocean Biology Processing Group of NASA for the distribution of the SeaWiFS products. This study forms a contribution to the Spanish Research project ECOTRANSPeer reviewe