Tuna sauce

tuna cans on supermarket shelf, with campaign stickers

“Supporting more sustainable and socially responsible fisheries, particularly those that are small-scale, is an essential part of any sound tuna sourcing policy.” http://www.greenpeace.org.uk/winning-worlds-largest-tuna-company-means-oceans/

Small-scale is defined as less than 2mm – or, in the realm of sound tuna, an octave in a minor key.