Holly Clayton and Dr. Richard Kellems, Plant and Animal Science
The June sucker was once the most abundant fish species in Utah Lake and its tributaries. Since April 30, 1986, the June sucker has been on the endangered species list. Some declines in species abundance is due to the competition of nonnative species and degraded water quality, both which can be attributed to the amount of common carp in Utah Lake. The June Sucker Recovery Implementation Program (JSRIP) desires to resolve the concerns of water development and large numbers of nonnative, sportfish predators and competitors by removing nearly all the common carp from Utah Lake.
Currently, the common carp, Cyprinus carpio, compose 74 percent of the fish within the lake. The June sucker accounts for less than 0.1 percent of fish in the lake. The JSRIP’s plan is to remove 75 to 90 percent of the carp found in the lake using commercial fishing techniques. This program will generate 14,915 to 17,898 tons of carp over a six to seven year period costing $5.97 million to $7.16 million to accomplish. With no large scale commercial processing plants or markets available in or near the State of Utah, the JSRIP has large amounts of fish that need potential uses.
Carp are high in protein, low in saturated fat, and within freshwater fish contain one of the highest levels of heart beneficial omega-3 fatty acids. Because of these features, I decided to find out if these components of the carp could be easily and economically separated so they could be used commercially in other products. In this research I extracted usable products (lipids, proteins, fatty acids) from liquefied carp to see if they contained significant amounts of these products so they could be used commercially. Tests on the amount of inorganic matter were also performed to see if there were significant amounts of metals in the fish that would prohibit the use of the carp for human consumption.
The carp for testing were provided by a commercial fisherman at Utah lake. All work on this project was done on BYU campus using machinery, methods, and analysis services available here.
In order to have a homogenous mixture, the fish were chopped into pieces and then liquefied. This liquefied product was then dried and ground into a powder for testing.
The fatty acids in the carp were leached out of the powder form and sent out for gas chromatography (GC) analysis through the food science department at BYU. The GC analysis tested for twenty-seven different amino acids. The major acids found in the carp were palmitic acid, palmitoleic acid, and oleic acid. The essential omega-3 fatty acids needed in nutrition were also found in the samples but in much smaller amounts. Only six samples were run for a fatty acid analysis with larger deviations from one another than desired. Further testing was suspended until liquefaction techniques were standardized to insure reliability of tests.
A perchloric acid digest method was used to determine the inorganic matter found in the carp. The samples were predigested with nitric acid and heated to destroy the organic matter. Then the perchloric acid was added to oxidize the inorganic matter in the carp. This oxidized material was put in an Inductively Coupled Plasma (ICP) unit for analysis. ICP is used for the detection of trace metals in environmental samples. The primary goal of ICP is to get elements to emit characteristic wavelength specific light which can then be measured. The inorganic elements in the carp are shown in Table 1.
The results listed are the averages found for all the samples tested. These results show that there is not a significant amount of harmful metals found in the carp that would prohibit their use for human consumption.
Crude protein and crude fat analyses were also done using machinery available through the soil department of BYU. In these tests each sample was analyzed separately. Almost 300 samples were run. The average result for the crude protein was that each fish contained 52.61% protein.
The crude fat analysis showed that the fish contained 21.56% fat.
All of these tests were done concurrently with other students performing tests on the best way to liquefy the fish as well as the best method to stabilize the liquefied product. As a result, the tests will be ongoing until methods are standardized throughout the process.
From this project I learned many problem solving skills. In the beginning I knew what needed to be accomplished and had to go to the library, my mentor, and other BYU faculty to determine the resources available that would help me accomplish my task. I learned how to use many new kinds of machinery and analyze different kinds of data. I was able to use this research experience in many job interviews this fall as evidence of my research abilities. Having this project listed on my resume prompted many questions and much interest in my laboratory skills. Overall, this was one of the most interesting research experiences I have had while I was in college.