A fisherman pulls a basket filled with anchovies aboard a fishing boat off of Peru's northern port of Chimbote, in 2012. Peru is the world's top fishmeal exporter, producing about a third of worldwide supply. Enrique Castro-Mendivil/Reuters/Landov hide caption itoggle caption Enrique Castro-Mendivil/Reuters/Landov The Salt Want To Reduce Your Carbon Footprint? Choose Mackerel Over Shrimp Sardines and other small, oily fish are some of the most nutritious in the sea. Now there's another reason to eat them: Fishermen use a lot less fuel to catch them than many other kinds of seafood.