Show Products By-Products Are Important in Fishing Industry Waste Used for Fertilizer Often forgotten about bout in casual thoughts of the fishing industry is the Importance of by These Thesa are principally meal fer fer- fertilizer fertilizer fer- fer fertilizer and oil which are manufactured manufactured manufactured from the waste of canneries and other fish plants In a big plant the waste may make up as much as half of the raw material materia Oils ons are arc extracted from all aU parts of the fish although the public Is most familiar with fish liver oils which as the name implies are arc ob ob- obtained obtained obtained only from fish livers Jivers An in in- interesting interesting interesting quirk observes a writer in the Chicago Tribune is that bodies of fish yielding liver oil are usually very lean while livers of fat fish contain little oil Medicinal oil oU is made from fresh livers al although al- al although l- l though stale livers are arc used in milk mak making m milking k- k king ing other oils oOs Oils are obtained either by press press- pressing pressing pressing ing and cooking of waste or simply by cooking the waste and skimming ming the oil oU oft off of the top of the vat Fish oils are used among other In making paints and varnish waterproofing wa wa- waterproofing waterproofing materials linoleum oleum li leather soap and lard substitutes subs Salmon sardines young herring h and tuna tuna tuna-In in addition to the well I I II Ii i r known cod cod are are important in con con- contributing contributing contributing oil oU from cannery waste to add to the supply obtained from whale porpoise and menhaden fishing Fish waste waste particularly particularly the scrap left after oil oU extraction Is Is being successfully used as a fertilizer er and is one of the most important sources of organic nitrogen The scrap is treated with acid and the resulting fish fertilizer often is mixed with other fertilizer com com- compounds compounds compounds pounds to form torm a complete fer ter- The feeding of fish and fish scrap to animals has been recommended and practiced for many years but it itis ItIs itIs is only In recent years that use of offish offish offish fish meal as a stock and poultry food tood has grown rapidly Like fertilizers meal is made from scrap It must be dried carefully and ground into granular form for poultry feed teed or into a rather fine meal for other purposes |