Reducing carbon emissions in aquaculture: Using Carbon Disclosures to identify unbalanced mitigation strategies

Abstract

The production of Scottish Atlantic salmon (Salmo salar) involves a global supply chain with greenhouse gases (GHG) emitted at every step. With the UK government setting a net zero target by 2050, and the Scottish Government having committed to achieving net zero by 2045, the Scottish salmon aquaculture sector now needs to start to develop and implement comprehensive emissions reductions measures. The methods demonstrated here and the identified imbalances in carbon emissions mitigation strategies provide a route to support this process. We use two international aquaculture operators in Scotland, Grieg Seafood and Mowi, as case studies to understand the scale of GHG emissions in the industry, how these compare to mitigation strategies, and where reduction efforts should be focused. Environmental data disclosed to the Carbon Disclosure Project (CDP), which includes in-depth breakdowns of GHG emissions in Scope 1, Scope 2 and Scope 3 categories were used for the first time in this comparison. This was contrasted with interview data from academics, industry experts and NGOs to identify routes to the most effective mitigation and reduction strategy. CDP data successfully identify imbalances between GHG emissions and mitigation strategies, and demonstrate that while Scope 1 emissions in Scottish aquaculture operations are high compared to other countries, Scope 3 emissions represent the majority of emissions. In terms of mitigation, Scope 1 and Scope 2 strategies are adequate, but Scope 3 mitigation strategies do not match the scale of emissions, identifying a potential route for future carbon emission reductions.