The study says that food production is responsible for a quarter of anthropogenic GHG emissions globally. However, marine fisheries are typically excluded from global assessments of GHGs or are generalized based on a limited number of case studies.
The researchers found that fisheries consumed around 40 billion litres of fuel in 2011 and generated a total of 179 million tonnes of CO2-equivalent GHGs, which is 4% of global food production.
Emissions from the global fishing industry increased by 28% between 1990 and 2011, with little increase in production, as the average emissions per tonne grew by 21%.
Growth in emissions was caused mainly by increased harvests from fuel-intensive crustacean fisheries.
The study notes:
The environmental benefit of low-carbon fisheries could be further realized if a greater proportion of landings were directed to human consumption rather than industrial uses.
See further details in the study on fishing industry GHG emissions.