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1. Life cycle assessment of aquaculture systems: Does burden shifting occur with an increase in production intensity?

   https://doi.org/10.1016/j.aquaeng.2020.102130  

   Ghamkhar, Ramin ; Boxman, Suzanne ; Main, Kevan ; Zhang, Qiong ; Trotz, Maya ; Hicks, Andrea ( January 2021 , Aquacultural engineering)

   Life cycle assessment (LCA), a tool used to assess the environmental impacts of products and processes, has been used to evaluate a range of aquaculture systems. Eighteen LCA studies were reviewed which included assess- ments of recirculating aquaculture systems (RAS), flow-through systems, net cages, and pond systems. This re- view considered the potential to mitigate environmental burdens with a movement from extensive to intensive aquaculture systems. Due to the diversity in study results, specific processes (feed, energy, and infrastructure) and specific impact categories (land use, water use, and eutrophication potential) were analyzed in-depth. The comparative analysis indicated there was a possible shift from local to global impacts with a progression from extensive to intensive systems, if mitigation strategies were not performed. The shift was partially due to increased electricity requirements but also varied with electricity source. The impacts from infrastructure were less than 13 % of the environmental impact and considered negligible. For feed, the environmental impacts were typically more dependent on feed conversion ratio (FCR) than the type of system. Feed also contributed to over 50 % of the impacts on land use, second only to energy carriers. The analysis of water use indicated intensive recirculating systems efficiently reducemore »water use as compared to extensive systems; however, at present, studies have only considered direct water use and future work is required that incorporates indirect and consumptive water use. Alternative aquaculture systems that can improve the total nutrient uptake and production yield per material and energy based input, thereby reducing the overall emissions per unit of feed, should be further investigated to optimize the overall of aquaculture systems, considering both global and local environmental impacts. While LCA can be a valuable tool to evaluate trade-offs in system designs, the results are often location and species specific. Therefore, it is critical to consider both of these criteria in conjunction with LCA results when developing aquaculture systems.« less
2. A regional assessment of land, irrigation water, and greenhouse gas emissions from canola biodiesel feedstock production in California

   Winans, K ; Yeo, B-L ; George, N ; Kendall, A ; Kaffka, S ( July 2017 , Proceedings of the International Symposium on Sustainable Systems and Technologies)

   The objective of this research is to evaluate the effects of cropping choices on land, water use for irrigation, and greenhouse gas emissions after introducing canola (Brassica napus L.) cultivation for the production of 60 million gallons of biodiesel per year. Characterization of regional farm-level cropping patterns and agronomic inputs and economic data are used to model the adoption of canola in place of the diverse incumbent cropping patterns in four regions of California: Northern and Southern San Joaquin Valleys, Sacramento Valley, and Southern California, using the Bioenergy Crop Adoption Model. The life cycle assessment approach is then used to assess environmental impacts due to cultivation of canola in place of the incumbent cropping patterns in terms of: (1) land use; (2) life-cycle greenhouse gas emissions due to direct land use change (kg CO2e ac-1); (3) greenhouse gas emissions due to irrigation water (kg CO2e ac-1); and (4) life-cycle greenhouse gas emissions expressed in grams of carbon dioxide equivalent per megajoule of biodiesel. Preliminary results show the adoption price of the canola with a yield of 1.5 U.S. tons per acre is estimated to be $481 per ton of canola in 2012 dollars at which point a total of 508,400more »acres appear in canola cultivation. This land area (508, 400 acres) is equivalent to approximately 89 million gallons of biodiesel from canola per year given the assumptions stated in this study. Consequentially, crops that are less profitable are replaced with canola and greenhouse gas emissions due to irrigation water are reduced while maintaining a diversified percentage of the incumbent cropping patterns, as well as canola cultivation.« less
3. A regional assessment of land, irrigation water, and greenhouse gas emissions from canola biodiesel feedstock production in California.

   Winans, K ; Yeo, B-L ; George, N ; Kendall, A ; Kaffka, S ( October 2016 , Proceedings of the International Symposium on Sustainable Systems and Technologies)

   The objective of this research is to evaluate the effects of cropping choices on land, water use for irrigation, and greenhouse gas emissions after introducing canola (Brassica napus L.) cultivation for the production of 60 million gallons of biodiesel per year. Characterization of regional farm-level cropping patterns and agronomic inputs and economic data are used to model the adoption of canola in place of the diverse incumbent cropping patterns in four regions of California: Northern and Southern San Joaquin Valleys, Sacramento Valley, and Southern California, using the Bioenergy Crop Adoption Model. The life cycle assessment approach is then used to assess environmental impacts due to cultivation of canola in place of the incumbent cropping patterns in terms of: (1) land use; (2) life-cycle greenhouse gas emissions due to direct land use change (kg CO2e ac-1); (3) greenhouse gas emissions due to irrigation water (kg CO2e ac-1); and (4) life-cycle greenhouse gas emissions expressed in grams of carbon dioxide equivalent per megajoule of biodiesel. Preliminary results show the adoption price of the canola with a yield of 1.5 U.S. tons per acre is estimated to be $481 per ton of canola in 2012 dollars at which point a total of 508,400more »acres appear in canola cultivation. This land area (508, 400 acres) is equivalent to approximately 89 million gallons of biodiesel from canola per year given the assumptions stated in this study. Consequentially, crops that are less profitable are replaced with canola and greenhouse gas emissions due to irrigation water are reduced while maintaining a diversified percentage of the incumbent cropping patterns, as well as canola cultivation.« less
4. A Life Cycle Assessment Approach for Vegetables in Large-, Mid-, and Small-Scale Food Systems in the Midwest US

   https://doi.org/10.3390/su132011368  

   Stone, Tiffanie F. ; Thompson, Janette R. ; Rosentrater, Kurt A. ; Nair, Ajay ( October 2021 , Sustainability)

   Although vegetables are important for healthy diets, there are concerns about the sustainability of food systems that provide them. For example, half of fresh-market vegetables sold in the United States (US) are produced in California, leading to negative impacts associated with transportation. In Iowa, the focus of this study, 90% of food is imported from outside the state. Previous life cycle assessment (LCA) studies indicate that food consumption patterns affect global warming potential (GWP), with animal products having more negative impacts than vegetables. However, studies focused on how GWP, energy, and water use vary between food systems and vegetable types are less common. The purpose of this study was to examine these environmental impacts to inform decisions to buy locally or grow vegetables in the Midwest. We used a life cycle approach to examine three food systems (large-, mid-, and small-scale) and 18 vegetables commonly grown in/near Des Moines, Iowa. We found differences in GWP, energy, and water use (p ≤ 0.001 for each) for the three food systems with the large-scale scenario producing more emissions. There were also differences among vegetables, with the highest GWP for romaine lettuce (1.92 CO2eq/kg vegetable) approximately three times that of leaf lettuce (0.65more »CO2eq/kg vegetable) at the large scale. Hotspots and tradeoffs between GWP, energy, and water use were also identified and could inform vegetable production/consumption based on carbon and water use footprints for the US Midwest.« less
5. Comparative environmental impact assessment of aqaufeed production: Sustainability implication of forage fish meal and oil free diets

   https://doi.org/doi.org/10.1016/j.resconrec.2020.104849  

   Ghamkhar, Ramin ; Hicks, Andrea ( January 2020 , Resources conservation recycling)

   The environmental sustainability of aquaculture food production systems is of critical concern due to its rapid expansion as the fastest growing major food production sector in the world. Among the parameters that con- tribute to the overall environmental impacts of aquaculture marine-based protein production, aquafeed is identified as an impact hotspot. There is consequently a need to seek more environmentally sustainable aqua- feeds to mitigate the adverse environmental impacts associated with aquaculture food production. The environmental and economic sustainability of aquafeeds can be improved using two main approaches: (a) optimizing finite resources use (e.g. fish meal and fish oil), and (b) mitigating waste generation and emissions. A variety of ingredients have been previously proposed, investigated, and utilized to accomplish these strategies, while maintaining acceptable food production efficiencies. However, comprehensive evaluation of the en- vironmental sustainability of aquafeeds with respect to variable ingredients, both in terms of resource use and waste emission has not been conducted. In this work, a holistic life cycle impact assessment of twelve practically formulated and utilized aquafeeds has been performed to provide a comparative evaluation of different aquafeed's environmental impacts, con- sidering resource use (biotic resource use, water intake, and fossil fuel depletion) and emission-based impactmore »categories (ozone depletion, global warming, photochemical smog, acidification, eutrophication, carcinogenics, non-carcinogenics, respiratory effects, and ecotoxicity). Results indicate that the investigated fish meal free diets do not, on the whole, result in a significant decrease in environmental impacts with respect to the use of biotic resources. However, if the substituted ingredients would not propose elevated impacts (e.g. blood meal), these diets can potentially lower the overall environmental impacts of aquafeed production mainly with respect to relevant emission-based indicators (e.g. global warming, eutrophication, ecotoxicity). Findings demonstrate that the investigated fish oil free diets can potentially lower the use of biotic resources. However, to prevent burden shifting, strategies to provide nutrient-rich oils with minimal energy requirement need to be undertaken.« less