Post-catch processing generates nearly twice the emissions produced by fishing itself, which is typically where the analysis of the climate impact of seafood ends, according to the findings, published in the journal Elementa: Science of the Anthropocene.
"The food system is a significant source of global greenhouse gas emissions, and Alaskan pollock is one of the biggest fisheries in the world," said study researcher Brandi McKuin from Unviersity of California in the US.
"These findings highlight the need to take a comprehensive approach to analysing the climate impacts of the food sector," McKuin added.
"Alaskan pollock is sold as fillets and trim pieces that are used to make products like fish sticks and imitation crab, it's a huge market," she said.
Unlike previous studies that have largely overlooked the downstream processing activities associated with Alaskan pollock, this study examined all the components of the supply chain, from fishing through the retail display case.
The results identify "hot spots" where the seafood industry could concentrate its efforts to reduce its climate impacts, said the researchers.
For the findings, the research team analysed the climate impacts of transoceanic shipping of exported seafood products.
They found that Alaskan pollock is a relatively fuel-efficient fishery: Pollock are caught in large nets called midwater trawls that are towed behind boats, hauling in a lot of fish in each landing and reducing the climate impact of the fishing process.
After the catch, Alaskan pollock are shipped for processing, and in some cases, transported on large container ships that burn copious amounts of fuel, including cheaper, poor-quality bunker fuel that produces high levels of sulfur particles.
The researchers noted that sulfur oxides from ship fuels have a climate-cooling effect.
"Seafood products that are exported have a lower climate impact than domestic seafood products," she said, adding that the climate impacts of shipping will change this year as new regulations for cleaner marine fuels take effect.
"Shipping has a massive influence on climate and a shift to cleaner fuels will diminish the cooling effect from sulfur oxides and increase the climate impact of products that undergo transoceanic shipping, including seafood," said McKuin.
( With inputs from IANS )