The objective of these studies was to develop an analog from surimi that would resemble abalone. Preliminary studies involved the standardization of batter preparation conditions, such as pH adjustment, optimum moisture content and batter mixing time. The texture of a gelled analog prepared with different protein adjuncts egg white, gluten and bovine serum albumin) was compared with cooked abalone for hardness, elasticity, and cohesiveness by a trained sensory evaluation panel and by instrumental methods. Serial levels of sodium carbonate were used to adjust the pH of the sol from pH 6.75 to 7.73. As the pH value rose, the textural strength of kamaboko correspondingly increased. The 0.1% level of sodium carbonate was determined suitable for further use. The moisture level in kamaboko caused significant variations in hardness (P<0.001) and cohesiveness (P<0.001). At the lowest level of moisture tested, 73.24%, gel hardness was greatest (l27N/g); with a 5% increase in moisture, the gel hardness was lower (52N/g). Sol mixing time (solubilization of myofibrillar proteins) was a very important factor to significantly affect gel texture for properties of hardness (P<0.00l), elasticity (P=0.002) and cohesiveness (P<0.001). To produce a strong, elastic and cohesive gel, 30 minutes mixing was required. In serial concentrations (O to 4%), egg white, gluten, and bovine serum albumin, were evaluated for enhancement of textural parameters in order to produce an imitation abalone product. The addition of either egg white or gluten at the two percent level resulted in the greatest hardness and most cohesive gels (P<0.001). Two percent added bovine serum albumin significantly improved gel hardness and elasticity (P=0.003 and P=0.0149, respectively). A shredded gel containing one of three protein adjuncts was effective in varying the final gel texture when incorporated with a surimi-based carrier. In overall parameters, the trained sensory evaluation panel judged the analog gel containing bovine serum albumin texturized chunks (at a 70:30 ratio to carrier) closest to cooked abalone. The instrumental measurements of textural parameters were slightly less discriminating than the trained sensory panel. / Graduation date: 1989

Thesis (M.S.)--University of Wisconsin--Stevens Point, 2009. / Submitted in partial fulfillment of the requirements of the degree Master of Science in Natural Resources (Fisheries), College of Natural Resources.) Includes bibliographical references (leaves 52-63).

Thesis (Ph.D.)--Trent University, 2001. / Includes bibliographical references.

Walleye fry stocking is common practice but success is rarely monitored. Use of oxytetracycline (OTC) can be used as a marking tool to identify stocked fish from naturally produced fish and determine stocking success. Through a series of experiments, parameters in the marking methodology were assessed for their effect on mark quality and retention of the mark over time. Mark quality was improved by marking fry at three days post hatch. Water source also significantly affected OTC mark quality. The use of powdered OTC produced higher quality marks than the use of liquid OTC. Retention of OTC marks was related to the quality of the OTC mark. Electrofishing surveys conducted on five lakes found high recruitment (>80%) among stocked walleye on two lakes, with more 40% recruitment on a third lake. This study found that stocked walleye fry were successfully recruited into the age 0+ year class. / October 2015

Thesis (M.S.)--University of Wisconsin -- La Crosse, 1977. / Includes bibliographical references (leaves 53-57).

No description available.

No description available.

Historically, the New River may have contained a genetically unique, river-spawning population of walleye (Stizostedion vitreum). Additionally, a number of genetically different walleye stocks have been stocked in Claytor Lake, Virginia. The increasing importance of the walleye fishery led to interest in clarifying key unknowns regarding the biology of the New River walleye stock. A radio telemetry study and genetic evaluation of present-day stocks led to identification of three spawning areas and the characterization of the genetic stock structure of walleye in Claytor Lake and the upper New River. Using radio telemetry to track movements of walleye, I determined that two resident walleye populations co-exist: one within Claytor Lake and the other in the New River above the lake. These populations establish spatially disjunct home ranges, remaining spatially separated throughout most of the year. Although there is no blockage to movement or migration, walleye within Claytor Lake generally spawn at Allisonia, while walleye within the upper New River spawn at Buck Dam. Some walleye from both populations spawn in other areas, such as Fosters Falls. Using allozymes, microsatellite DNA, and mitochondrial DNA marker techniques to examine population structure of walleye, I determined that the walleye within Claytor Lake are a panmictic population. This is the result of years of stocking walleye from different genetic stocks and interbreeding among individuals. The genetic structure of walleye from the New River also shows the presence of more than one genetic stock. Within the New River population, there exists a genetic stock of walleye that is characterized by three mitochondrial DNA haplotypes (43, 44, and 45) that previously have not been seen. This may be indicative of a unique walleye stock that is native to the New River and which has remained spatially or temporally segregated by spawning habits. The co-existence of two different walleye populations in the Claytor Lake / upper New River system justifies different management strategies. I recommend that management of the walleye population in Claytor Lake focus on increasing the exploitation of this non-indigenous stock. Management of the upper New River walleye population should focus on conservation of the unique native stock through supportive breeding and/or strict harvest regulations. / Master of Science

Lake Winnipeg has the second largest walleye fishery in North America. The North and South Basins of the lake differ in many ways, e.g. water temperature, turbidity, and fish community. The study objectives were to determine if (a) growth, condition or diet of walleye, sauger or dwarf walleye differed between basins, (b) among seasons, and (c) whether the invasive rainbow smelt are associated with these differences. Walleye, sauger and dwarf walleye were caught using gill-nets and analysed for growth, condition and diet in all seasons. Walleye and sauger in the North Basin showed higher growth rates and condition than in the South Basin. Diet in the South Basin had more diverse species composition, whereas in the North Basin, the diet consisted almost entirely of rainbow smelt. Some seasonal variation was also documented and the impact of rainbow smelt seems to be positive for these piscivorous fish in Lake Winnipeg.

Lake Winnipeg has the second largest walleye fishery in North America. The North and South Basins of the lake differ in many ways, e.g. water temperature, turbidity, and fish community. The study objectives were to determine if (a) growth, condition or diet of walleye, sauger or dwarf walleye differed between basins, (b) among seasons, and (c) whether the invasive rainbow smelt are associated with these differences. Walleye, sauger and dwarf walleye were caught using gill-nets and analysed for growth, condition and diet in all seasons. Walleye and sauger in the North Basin showed higher growth rates and condition than in the South Basin. Diet in the South Basin had more diverse species composition, whereas in the North Basin, the diet consisted almost entirely of rainbow smelt. Some seasonal variation was also documented and the impact of rainbow smelt seems to be positive for these piscivorous fish in Lake Winnipeg.