Climate-Friendly Seafood: The Potential for Emissions Reduction and Carbon Capture in Marine Aquaculture

Abstract

Aquaculture is a critical food source for the world's growing population, producing 52% of the aquatic animal products consumed. Marine aquaculture (mariculture) generates 37.5% of this production and 97% of the world's seaweed harvest. Mariculture products may offer a climate-friendly, high-protein food source, because they often have lower greenhouse gas (GHG) emission footprints than do the equivalent products farmed on land. However, sustainable intensification of low-emissions mariculture is key to maintaining a low GHG footprint as production scales up to meet future demand. We examine the major GHG sources and carbon sinks associated with fed finfish, macroalgae and bivalve mariculture, and the factors influencing variability across sectors. We highlight knowledge gaps and provide recommendations for GHG emissions reductions and carbon storage, including accounting for interactions between mariculture operations and surrounding marine ecosystems. By linking the provision of maricultured products to GHG abatement opportunities, we can advance climate-friendly practices that generate sustainable environmental, social, and economic outcomes.

A global and regional view of the opportunity for climate-smart mariculture

“…While these sectors typically generate lower levels of GHG emissions than others [4], excessive transport (e.g. to and from a hatchery, processing or market facilities located large distances from production sites) and energy-intensive facilities could undermine this value unless renewable energy sources are used [69]. Displacement of climate-related impacts could also occur in the expansion or transition of mariculture feed.…”

“…For example, production of popular finfish species such as salmonids can be more energy intensive in land-than seabased systems [68]. As such, the effects of expanding production on land, in an attempt to lessen nutrient-based impacts on marine habitats and species, could result in increasing GHG emissions [69]. The nature of such tradeoffs will be influenced by local factors, including the availability of renewable energy and biofuels, the type and quality of infrastructure and the source of supporting services royalsocietypublishing.org/journal/rstb Phil.…”

Reforming International Fisheries Law Can Increase Blue Carbon Sequestration

“…Analysis of carbon sequestration needs to also consider interactions between wild fishery resources and aquaculture to provide more comprehensive and integrated assessments of coastal ecosystems (Jones et al, 2022). For example, the Intergovernmental Panel on Climate Change (IPCC) has recommended macroalgal production as a research field for climate change mitigation (IPCC, 2019), an ocean-based climate change mitigation also suggested by the High-Level Panel for a Sustainable Ocean Economy (Stuchtey et al, 2020).…”

Plenty more fish in the sea? – is there a place for seafood within a healthier and more sustainable diet?

“…Other opportunities are being explored for the sustainable intensification of aquaculture. A few examples include the use of industrial fish processing waste as a substrate to generate biogas (methane) (Bücker et al, 2020), the harvesting of farmed bivalves by hand, and even utilisation of shell waste (as calcium carbonate or calcium oxide) within the construction industry (Jones et al, 2022).…”