Oil

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Q 1.
	What percent by weight of oil is contained in cod livers?
Q 2.
	One of my friends told me that menhaden is produced in greater quantities than any other fish in Florida. I don't recall ever hearing of menhaden. Could you tell me something about this fish?
Q 3.
	We were shown a movie at our school last week, showing how menhaden were caught and processed into fish meal, oil and fertilizer. Is there any other uses which such non food fish could be put to?
Q 4.
	What are “trashfish?”
Q 5.
	I understand that a large part of the fish caught in Florida are menhaden. What use is made of this fish?
Q 6.
	What was the old method of obtaining cod liver oil?
Q 7.
	What as some of the potential uses for the waste from fish used for canning?
Q 8.
	What is the length of a 650-pound bluefin tuna and the major and minor diameters of the largest cross section? We would also like to know the approximate percentage of solids and the chemical composition of these fish. We have in mind stock-piling chopped up palm fronds during the winter and then during the fishing season grinding up any surplus fish, mixing them with the palm frond shavings and composting to produce soil.
Q 9.
	I am planning to conduct an experiment on growing plants in shell fertilizer. Can you give me any information on this subject?
Q 10.
	I would appreciate any available information on a simple process for extracting fish oil from fish.
Q 11.
	Do the concentrated brine by-products of seawater desalination contain economically recoverable quantities of nitrates and phosphates usable in fertilizers, or other metals for industrial use such as bromine? If so, could marketing of such materials improve the cost effectiveness of desalting sea-water for public water supplies?


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	Q&A 1.	What percent by weight of oil is contained in cod livers?
	Cod liver oil may range from 15 to 65 per cent of the liver, depending on a number of factors, such as the age of the fish, time of year it was caught, and the particular type of food on which it had been feeding. Cod taken inshore usually have a fat, whitish, very soft liver, whereas cod taken at sea have lean livers ranging from pink to red and are more difficult to render. Cod liver oil contains not only vitamin A but also vitamin D in appreciable amounts.
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	Q&A 2.	One of my friends told me that menhaden is produced in greater quantities than any other fish in Florida. I don't recall ever hearing of menhaden. Could you tell me something about this fish? Tampa, Florida
	The menhaden is the first ranking fish in the United States in pounds produced, although the tuna, salmon, shrimp and others are higher ranking in dollar value. Menhaden can be eaten but rarely is since it acquires a rancid or oily flavor unless very fresh. The menhaden is a small (average 2/3 lb.) fish which lives in hugo schools in the Atlantic Ocean. There are four different kinds in North American waters, Brevoortia tyrannus being the principal one, and two species in South American waters. They go under many different common names, pogie being the most common in Florida; they are also called fatbacks, mossbunkers and old wives. The name menhaden itself comes from the Indian name - - munnawhatteaug. Like their herring relatives, they are silvery colored, and without spines in their fins. Because of the schooling habit of the menhaden, it can be caught best in pwrno seines. In colonial America, it was utilized by both the Indians and the colonists as fertilizer, but later the oils were separated out and used in lubricants, tanning, rope making, paints, lamp oils, and other uses. The meal is no longer used as fertilizer but is now employed to fortify poultry and swine feeds. Fish meal is a source of high quality proteins, minerals, and vitamins, and manufactured feeds containing fish meal cause markedly faster growth in poultry than feeds without fish meal. New York now represents the northern limit of menhaden reduction plants, with Beaufort being the center; Fernandina Beach, Florida, is the southern limit on the Atlantic coast. Recently reduction plants have been established on the western Gulf of Mexico.
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	Q&A 3.	We were shown a movie at our school last week, showing how menhaden were caught and processed into fish meal, oil and fertilizer. Is there any other uses which such non food fish could be put to? Jacksonville, Florida
	After many years of research the South African Fishing Industry Research Institute has developed a commercially adaptable process for the production of a neutral fish flour from the cheap and abundant maasbanker or horse mackerel Trachurus trachurus, as it is called in the United States. This fish flour can be introduced to such foods as bread without altering the taste, smell or color. Neutral fish flour is no revolutionary discovery and has actually been produced years ago in some of the more highly developed fishing nations. What the Research Institute has achieved is a process ideal for large scale production using raw material sufficiently cheap to make the project a more reasonable business proposition. The processing methods adopted go through four stages: (1) A special solvent is added to remove the oil. After the solvent has removed the oil a cheap and easy way of rendering the solvent neutral and available for continued use was found. (2) Faint traces of smell and flavor are removed together with certain off-flavors. (3) Residual trace flavors are effectively masked. (4) Whatever minute trace of smell or flavor remains is caged in each flour particle. The flour developed by this process is of very high quality and well suited for human consumption.
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	Q&A 4.	What are “trashfish?” Lewes, Delaware
	In commercial fishing, the term “trashfish” or simply “trash” is used to designate the innumerable species of marine animals that are caught while fishing for a specific commercial fish. In shrimp fishing especially, several hundred pounds of trashfish are often taken in securing a hundred pounds of shrimp or less. "Trashfish" include many species of fish, crustaceans (i.e., crabs, and noncommercial shrimp), mollusks, sponges and so on. At present certain research organizations are making an effort to find further channels of utilization of trashfish. In most fisheries, the trash is dumped overboard after the desired species is sorted out. In a few areas there are processing plants which utilize trashfish in the production of fish meal, fertilizer, and animal food.
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	Q&A 5.	I understand that a large part of the fish caught in Florida are menhaden. What use is made of this fish? Cleveland, Ohio
	The menhaden are caught in large quantities and used to make fish meal and fish solubles. This meal is highly esteemed as a source of quality protein, minerals and vitamins and is used in manufactured mixed feeds for swine or poultry. It is one of the more expensive ingredients and is rarely used in larder amounts than 5 percent of the mixture. The solubles are used for much the same purpose as a protein and vitamin supplement. Another product, menhaden oil, is used as a drying oil in special paints, varnishes, inks, caulking compounds and many other products. A part of this oil, also is used by soap, cosmetic and pharmaceutical firms.
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	Q&A 6.	What was the old method of obtaining cod liver oil? Miami, Florida
	The oldest and simplest method of rendering cod liver oil is the sun-rotting process, in use about 100 years ago. This process is no longer in use for which we can be thankful to the progress made by scientists in finding more efficient processes which also make the oil more palatable. By the old method the livers were simply piled in covered drums and allowed to decompose in the sun. Eventually the oil would separate from the disintegrating material and come floating to the top. This dark, foul-smelling liquid, although it did contain some of the beneficial vitamins A and D, was certainly not pleasant to the taste.
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	Q&A 7.	What as some of the potential uses for the waste from fish used for canning? Pittsburg, Pennsylvannia
	Since the portion of fish not used for canning may be about 30 per cent of the fish much research has been directed to find ways of utilizing the entire fish. Some of the by-products that have been found to offer a potential for cannery waste are meal-for animal feeding and as a fish hatchery food, fats and oils - for use in chemical and baking industries, vitamins - for use in pharmaceuticals, proteins - for medicinal use and as a growth media for production of anti-biotics, enzymes and hormones - for use in medicine and miscellaneous organic compounds - for use in synthetic organic chemistry and medicine.
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	Q&A 8.	What is the length of a 650-pound bluefin tuna and the major and minor diameters of the largest cross section? We would also like to know the approximate percentage of solids and the chemical composition of these fish. We have in mind stock-piling chopped up palm fronds during the winter and then during the fishing season grinding up any surplus fish, mixing them with the palm frond shavings and composting to produce soil. Cat Cay, Bahamas
	The length of a 650-pound bluefin tuna is about nine feet. The girth would be about 56 inches. Its major and minor diameters of the largest cross section would be approximately 37 and 24 inches. Solids from various species of tuna vary from 33 to 38 per cent. No information is available on the chemical composition of bluefin tuna but albacore is 22 to 25 per cent protein, 6 to 13 per cent oil and one and one-tenth to one and two-tenths minerals, while yellowfin tuna has 22 to 29 per cent protein and 6 to 13 per cent oil. It is believed that differences between the various species are only minor.
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	Q&A 9.	I am planning to conduct an experiment on growing plants in shell fertilizer. Can you give me any information on this subject? Belize, British Honduras, California
	The term "shell" in everyday use usually refers to a variety of materials whose biological origin is associated with crabs, lobsters, shrimp and mollusks, all of which are referred to as shellfish. It is believed that in the sense of "shell" fertilizer, the term applies to crab and lobster shell, which is ground up and used to enrich the soil. This has been done in the United States for many years using horseshoe crabs (Limulus). Some of this type of shell is quite rich in organic material, which furnishes fertilization while the lime-like substance lowers acidity. You may find information concerning the use of this shell in the latest edition of Marine Products of Commerce, by Tressler and Lemon, published by Reinhold Book Division, New York, New York.
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	Q&A 10.	I would appreciate any available information on a simple process for extracting fish oil from fish. Ft. Myers Beach, Florida
	To obtain oil from a marine fish it would be advisable to begin with a fish whose flesh and viscera are fatty, such as the mullet. The simplest way to extract the oil would be to grind the entire fish into approximately four volumes of acetone. This will extract the fat and leave most other components behind. It is then necessary only to evaporate the solvent (using considerable care, because it is highly inflammable) to obtain the oil. If further purification is desired, chill the oil briefly in the refrigerator. This will generally result in the crystallization of steroids, leaving a transparent, clear oily layer floating on top.
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	Q&A 11.	Do the concentrated brine by-products of seawater desalination contain economically recoverable quantities of nitrates and phosphates usable in fertilizers, or other metals for industrial use such as bromine? If so, could marketing of such materials improve the cost effectiveness of desalting sea-water for public water supplies? Indialantic, Florida
	Though saltwater desalination is playing an increasingly important; role in the development of coastal cities, the potential of fertilizer extraction from brine by-products has not been considered in the United States to date. The economic feasibility of bromine nitrate or phosphate extraction appears to be poor in light of the very low concentrations of these particular salts in brine (less than 20 parts per million in normal seawater). In other countries, brine solutions from the desalination process are allowed to evaporate in outdoor pools where potassium salts are later extracted. This may not be economically justifiable on its own merit, but it serves to reduce overall desalination costs. A much more concentrated source of fertilizers is the residential primary and secondary treated sewage effluents which are a major pollution component.
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	Rosenstiel School of Marine & Atmospheric Science Library University of Miami, FL USA 4600 Rickenbacker Causeway, Miami, Florida 33149 Phone: 305 421 4060 Fax: 305 421 9306 E-mail: libcirc@rsmas.miami.edu		go to the top