Thanks for clarifying too! I agree the increased cost of wild sardines and anchovies would tend to increase the production of alternative feed for the fish being fed wild sardines and anchovies. However, more than 1 kg of alternative feed would be needed to produce 1 kg of farmed fish. So humans eating 1 kg more of wild sardines and achovies would result in more than 1 kg more of alternative feed. As a result, eating wild sardines and anchovies instead of plant-based foods would still increase agricultural land if 1 kg of alternative feed requires as much agricultural land as 1 kg of the replaced plant-based foods.
Thanks Vasco, I really appreciate your thoughtful engagement!
I agree that feed conversion losses mean more than 1 kg of alternative feed would be needed to produce 1 kg of farmed fish. So if that alternative feed uses as much land as the replaced plant-based food, land use could indeed increase. However, many promising feed alternatives (based on microbial fermentation, insects, or algae) may have a much smaller land footprint than typical crops grown for human consumption. So the net effect on land use depends on what those alternatives are. That said, many current feed alternatives might be less efficient.
I think itās important to also consider not just the calories or kilograms involved, but the nutritional value. Sardines and anchovies are exceptionally nutrient-dense, as discussed in the āHealth and Nutritionā section. So even if land use were slightly higher per kilogram, the nutritional return per land area might still be better. Itās definitely a complex question, and Iād love to see more data on this.
Thanks for clarifying too! I agree the increased cost of wild sardines and anchovies would tend to increase the production of alternative feed for the fish being fed wild sardines and anchovies. However, more than 1 kg of alternative feed would be needed to produce 1 kg of farmed fish. So humans eating 1 kg more of wild sardines and achovies would result in more than 1 kg more of alternative feed. As a result, eating wild sardines and anchovies instead of plant-based foods would still increase agricultural land if 1 kg of alternative feed requires as much agricultural land as 1 kg of the replaced plant-based foods.
Thanks Vasco, I really appreciate your thoughtful engagement!
I agree that feed conversion losses mean more than 1 kg of alternative feed would be needed to produce 1 kg of farmed fish. So if that alternative feed uses as much land as the replaced plant-based food, land use could indeed increase. However, many promising feed alternatives (based on microbial fermentation, insects, or algae) may have a much smaller land footprint than typical crops grown for human consumption. So the net effect on land use depends on what those alternatives are. That said, many current feed alternatives might be less efficient.
I think itās important to also consider not just the calories or kilograms involved, but the nutritional value. Sardines and anchovies are exceptionally nutrient-dense, as discussed in the āHealth and Nutritionā section. So even if land use were slightly higher per kilogram, the nutritional return per land area might still be better. Itās definitely a complex question, and Iād love to see more data on this.
Makes sense. Thanks for all your engagement too, Chris!