Environmental performance of rainbow trout (Oncorhynchus mykiss) production in Galicia-Spain: A Life Cycle Assessment approach.

Aquaculture is an increasingly important supplier of food worldwide. However, due to its high dependence on agricultural and fishing resources, its growth is constantly constrained by environmental impacts beyond aquaculture production systems. Within the European Union, Spain accounts for approximately 25 % of total aquaculture production, which implies that environmental impacts in rivers and marine ecosystems must be monitored to understand the role of aquaculture systems. While studies on the environmental performance of mussels or turbot production have been reported in the literature, Spanish rainbow trout (Oncorhynchus mykiss) has not received much attention despite its relative importance. In this sense, a Life Cycle Assessment (LCA) study of rainbow trout produced in a medium-sized plant in Galicia (NW Spain) was carried out in the present study. The study considered the production of round weight trout, as well as some commonly produced processed products, including filleting. The life cycle modelling included a high level of primary data in the foreground system. In addition to the widely considered environmental impact categories for this activity (e.g., global warming potential, terrestrial acidification and freshwater eutrophication), the recent proposed antibiotic resistance (ABR) enrichment impact category was included to explore the potential impact of antibiotic release in freshwater microbiota. The results highlighted the high contribution of aquafeed to most impact categories, due to upstream agricultural and fishing processes, whereas farm operation was responsible for the larger part of the impact in freshwater eutrophication, mainly due to direct emissions of nutrients from fish feeding. Amoxicillin release to recipient water bodies was the main driver to the ABR enrichment category. In contrast, the processing phase (i.e., gutting, freezing and packaging) showed low environmental burdens. In order to improve the environmental performance of the rainbow trout production system, decreasing the feed conversion ratio (FCR), shifting to renewable energy, using low environmental burden ingredients in aquafeed, and alternatives to control diseases without antibiotics could be considered.

Life cycle assessment of fish and seafood processed products - A review of methodologies and new challenges.

Life cycle assessment (LCA) has been widely applied in many different sectors, but the marine products and seafood segment have received relatively little attention in the past. In recent decades, global fish production experienced sustained growth and peaked at about 179 million tonnes in 2018. Consequently, increased interest in the environmental implications of fishery products along the supply chain, namely from capture to end of life, was recently experienced by society, industry and policy-makers. This timely review aims to describe the current framework of LCA and its application to the seafood sector that mainly focused on fish extraction and processing, but it also encompassed the remaining stages. An excess of 60 studies conducted over the last decade, along with some additional publications, were comprehensively reviewed; these focused on the main LCA methodological choices, including but not limited to, functional unit, system boundaries allocation methods and environmental indicators. The review identifies key recommendations on the progression of LCA for this increasingly important sustaining seafood sector. Specifically, these recommendations include (i) the need for specific indicators for fish-related activities, (ii) the target species and their geographical origin, (iii) knowledge and technology transfer and, (iv) the application and implementation of key recommendations from LCA research that will improve the accuracy of LCA models in this sector. Furthermore, the review comprises a section addressing previous and current challenges of the seafood sector. Wastewater treatment, ghost fishing or climate change, are also the objects of discussion together with advocating support for the water-energy-food nexus as a valuable tool to minimize environmental negativities and to frame successful synergies.

Alkaline and oxidative pretreatments for the anaerobic digestion of cow manure and maize straw: Factors influencing the process and preliminary economic viability of an industrial application.

This paper studies the application of calcium oxide (CaO), peracetic acid (PAA) and a combination of both in order to reduce lignin content and increase biogas potential of cow manure and maize straw. Changes in organic matter were mainly affected by the type of reagent use and the dosage, with minimum influence of exposure time and dilution. Changes in pH may limit the application of chemicals. Increase in biogas production with a combination of CaO and PAA, and separate application of PAA and CaO was 156.5%, 39.1% and 26.1% for cow manure and 125%, 137.5% and 37.5% for maize straw, respectively, compared to unpretreated samples. Pretreating cow manure with the aforementioned reagents does not increase the profitability of a biogas plant due mainly to the increase in operational costs from the intensive use of chemicals.