Tue, Aug 16, 2022: 2:00 PM-2:15 PM
515A
Background/Question/MethodsMultiple carp species have invaded North America’s waterways, causing significant ecological impacts. Commercial harvest remains the most cost-effective control method for invasive carp. However, low prices and market demand have limited the success of this strategy as a means of controlling the impacts from these invasive species in the Mississippi River. Certain regions, such as major tributaries in Illinois, have established a successful fishery through the inclusion of invasive carp products in pet and aquaculture feeds. Here, we assess the utility of expanding these initiatives to the Lower Mississippi River Basin by determining the compositional quality of invasive carp as well as the performance of carp products as feed ingredients in practical catfish diets. Invasive carp were sourced from two regions in Louisiana and one region in Illinois. Whole fish samples were compared between regions for proximate composition, amino- and fatty acid analysis, stable isotope analysis, and the presence of major contaminants. Further, invasive carp fishmeal and fish oil were incorporated into diets for catfish fingerlings. Catfish were fed one of six treatment diets for 8 weeks and growth, feed intake, feed efficiency, and proximate composition assessed.
Results/ConclusionsCarp are markedly larger in the Lower- (Louisiana, mean length 97 ± 15 cm) compared to Upper Mississippi River (Illinois, mean length 62 ± 8 cm). Preliminary results suggest that protein (19.2 ± 0.8) and fat (4.6 ± 1.5) are higher in Louisiana carp compared to Illinois (protein: 14.8 ± 1.3, fat: 3.8 ± 2.5), while ash content is lower in Louisiana (1.4 ± 0.2) compared to Illinois carp (5.3 ± 0.6). Further, long-chain polyunsaturated fatty acids are higher in Louisiana carp (31.2 ± 0.4 vs 15.0 ± 5.6 in Illinois), potentially as a result of different food sources. Catfish readily consumed feeds with carp fishmeal and fish oil. In carnivorous fish species, such as trout, hybrid striped bass, and cobia, these products elicit similar growth and digestibility values as traditional marine-derived sources of protein and fat. Our results suggest that Louisiana's invasive carp may serve as a valuable and sustainable source of alternative ingredients for aquaculture feeds. This finding is the first step towards developing a market for the carp fishery, whose harvest will benefit Louisiana's river ecosystems and native fish populations.
Results/ConclusionsCarp are markedly larger in the Lower- (Louisiana, mean length 97 ± 15 cm) compared to Upper Mississippi River (Illinois, mean length 62 ± 8 cm). Preliminary results suggest that protein (19.2 ± 0.8) and fat (4.6 ± 1.5) are higher in Louisiana carp compared to Illinois (protein: 14.8 ± 1.3, fat: 3.8 ± 2.5), while ash content is lower in Louisiana (1.4 ± 0.2) compared to Illinois carp (5.3 ± 0.6). Further, long-chain polyunsaturated fatty acids are higher in Louisiana carp (31.2 ± 0.4 vs 15.0 ± 5.6 in Illinois), potentially as a result of different food sources. Catfish readily consumed feeds with carp fishmeal and fish oil. In carnivorous fish species, such as trout, hybrid striped bass, and cobia, these products elicit similar growth and digestibility values as traditional marine-derived sources of protein and fat. Our results suggest that Louisiana's invasive carp may serve as a valuable and sustainable source of alternative ingredients for aquaculture feeds. This finding is the first step towards developing a market for the carp fishery, whose harvest will benefit Louisiana's river ecosystems and native fish populations.