It takes a little bit of fuel, but as you know, agriculture can have a carbon footprint, and fish has a much smaller one, so it's less polluting.
不过，出海捕鱼只需要很少的燃料， 相比起农业的碳排放量， 捕鱼产生的碳排放要少得多， 所以捕鱼造成的污染更少。