Browsing by Author "Kutka, Frank"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
Item A Comparison of Macroinvertebrate Communities, Habitat, and Water Chemistry Along the Length of Miller Creek(University of Minnesota Duluth, 1992) Richards, Carl; Tucker, Paul; Kutka, FrankBiological communities in streams can serve as useful monitors of habitat and chemical conditions. Recently, the use of biomonitoring to examine water resource quality has become a popular alternative, or addition to standard water assessment protocols for the purposes of management and planning, problem prioritization, and documentation of recovery following remediation efforts. A general theoretical framework for the development of biosurveys has been discussed by Karr (1991). The advantages of using biosurveys for monitoring and assessment purposes include: 1) biological communities reflect overall ecological integrity and therefore may be the most accurate status of a waterbody, 2) biological communities integrate the effects of different pollutant stressors and thus provide a measure of aggregate impact, 3) biological communities integrate stresses over time and provide an ecological measure of fluctuating environmental conditions 4) routine biological monitoring can be relatively inexpensive compared to the costs of detailed chemical and toxicity testing, 5) biological communities are often of direct interest to the public as an indicator of a pollution free environment. Macroinvertebrate communities in streams are effective biomonitors in streams that are relatively stable in time and reflect subtle differences in environmental conditions (Richards and Minshall 1992). Furthermore, general guidelines towards development and use of these communities for biomonitoring have been published widely (Plafkin et al. 1989, OHIO EPA 1987). These approaches follow the suggestions of Karr (1991) in that they utilize multiple community metrics to evaluate instream biological impairment. This approach consists of analyzing different components of the structure and function of macroinvertebrate communities. Each metric contributes ecological information on the integrity of the community in question. Several studies have reported the use of the metric approach with macroinvertebrates in streams (Barbour et al. 1992). Since many aspects of biological communities are dependant on regional and local characteristics, it is necessary to interpret biomonitoring data in light of unique regional characteristics. The purpose of the present study was to examine macroinvertebrate communities at several locations along Miller Creek to determine if biomonitoring techniques indicate significant problems along the watercourse, to compare various techniques for assessment, and to provide a preliminary database for future comparison.Item Economic and Technologic Development for the Crayfish Industry in Minnesota: Final Report(University of Minnesota Duluth, 1992) McDonald, Michael E; DeVore, Philip; Richards, Carl; Skurla, James A; Gunderson, Jeffrey; Kutka, Frank; Merrick, GlennThe potential to develop a viable crayfish industry in Minnesota currently exists. Crayfish biomass in our inland lakes can greatly exceed that of fishes; existing harvest techniques appear to have very little impact on the year-to-year crayfish population. Thus, Minnesota's crayfish appear to be an abundant and resilient resource. There are markets for soft and hard shell crayfish for food, soft and hard shell crayfish for bait, and peeled tail meat. A Minnesota crayfish product could currently be inserted in any of these markets, but crayfish as a bait appears to be the most attractive market. There is a very high seasonal demand for bait crayfish and the wholesale prices can be in the range of $15 to $25 per lb for soft shells. In addition to bait markets, large hard shell crayfish for food have a strong international export market, but this market requires that sufficient quantities be shipped at the right times. Also, there is local interest in peeled tail meat for retail sale. We examined four widely distributed Orconectes species (O. virilis, O. propinquus, O. rusticus, O. immunis) to assess commercial soft shell production potential. Crayfish were held in production-sized shallow trays with 2 cm of water at constant temperature similar to that used for commercial soft shell production. Molting success was examined as a function of capture date, sex, and stage of maturity. The timing of life cycle events dictates to a large extent the availability and soft shell production potential of wild caught crayfish, particularly in northern latitudes where market-sized crayfish are often nonjuveniles. Adults typically molt two to three times per growing season, associated with reproductive cycles. Molting rate in the laboratory was highest when crayfish were captured just prior to the wild molt. The first molt of the season was much more synchronous than the second molt. Molt timing varied by sex. Premolt Orconectid crayfish did not change color like Procambarus sp. but could be identified by the decalcification of the cheliped merus. The harvest of several species may be required to optimize soft shell production since synchronous molts occur at different times for different species. Our economic assessment of the crayfish food market suggests that it is relatively flat. This is due to: continued high production costs (including the lack of a proven tail meat separator); regional consumption (primarily in the south-central and Pacific states); unsophisticated packaging and marketing; and seasonally available supply. Crayfish are used in much of the Midwest for fishing bait. Since it is illegal to sell live crayfish for bait in Minnesota, markets in other states will have to be targeted. Problems to overcome include reducing mortality of crayfish shipped to out-of-state markets and drops in sales when crayfish are available closer to the markets. We have analyzed the economic feasibility of food and bait soft shell crayfish production facilities using flow-through and recirculating systems for the first two years of operation. Bait crayfish production in a recirculating system appeared to be the most profitable operation and food crayfish production in a flow-through system appeared to be the least profitable operation. The processing of large quantities of crayfish for a commercial tail meat operation in Minnesota requires that an inexpensive, automated system be developed in order to maintain the product's economic viability. We have evaluated the necessary engineering design components for developing a relatively inexpensive automated crayfish processing system, which could be linked to extant tail meat extruders. We feel that such a system is feasible, and could cost less than $15,000 retail.Item A Winter Survey of Fishes in the Vicinity of the WLSSD Sewage Treatment Plant: November 1991-April 1992(University of Minnesota Duluth, 1992) Richards, Carl; Kutka, Frank; Tucker, PaulThe Western Lake Superior Sanitation District’s (WLSSD) waste treatment facility on the shore of the St. Louis River estuary contributes a large volume of warm effluent to the St. Louis River on a continuous basis. The effluent mixes with the river in a relatively shallow embayment adjacent to the treatment facility and forms an area approximately 0.5 kilometer in diameter in which water temperatures and conductivities may be considerably different than surrounding river waters. This mixing zone can also have chemical characteristics that contrast significantly with unmixed river water. During winter conditions, elevated temperatures within the mixing zone may provide a potential refuge for fish species that are unable to exist in the cold waters of the river, and, some native species may seek warmer temperatures during winter when they are available. Alternatively, fish species may avoid the elevated temperatures or water chemistry characteristics of the mixing zone. Either of these situations could result in altered fish community characteristics during winter months. The purpose of this study was to provide preliminary data on the types and relative abundances of fish that inhabit the mixing zone during several winter months. Surveys were only conducted within 0.3 km of the outfall pipe; results were compared to other winter fish abundance data from the St. Louis River estuary.