A protein's carbon footprint is decided largely by three variables: feed efficiency, food-miles and refrigeration. On all three, locally-stewarded freshwater fish performs meaningfully better than the marine alternatives Kolkata kitchens default to.
1.4
kg CO₂e / kg reserve freshwater
5.6
kg CO₂e / kg imported marine
48 km
average reserve food-miles
2,200 km
average imported marine food-miles
Why the gap is structural
Marine fishing is fuel-intensive (trawlers), refrigeration-intensive (long hauls), and overcaught (longer trips per kilo). Pond aquaculture, run honestly, runs the table on all three.
Key takeaways
- Reserve freshwater fish has roughly a quarter the carbon footprint of imported marine.
- The win is driven by short food-miles and lower refrigeration overhead.
- Industrial aquaculture does not enjoy the same advantage.
