TunaMud: a new multi-purpose fertilizer from the canned tuna industry

Sewage sludge residue resulting from wastewater treatment at canned tuna industry factories is a multi-purpose fertilizer dubbed herein “TunaMud”. Tested on arboreal (olive and pomegranate), herbaceous (pepperoni and lettuce), and horticultural (onion) plants, TunaMud improved the growth parameters of all plants grown, as well as the quality of fertilized soil. A biological resource so far disposed of as biowaste at substantial economic cost is thereby turned into a valued fertilizer. Along with recent outcomes concerning tuna industrial processing waste upgrade into valuable bioproducts, these findings close the material cycle through technically and economically viable circular economy processes for all by-products of the global canned tuna industry, including wastewater treatment by-product.