No description available.

I investigated dietary differences, overlap and shifts for two atherinid fish species inhabiting the highly modified Tennessee-Tombigbee Waterway (TTW) in Mississippi, U.S.A. The Mississippi silverside (Menidia audens) is now common throughout the waterway and apparently invaded from the Tennessee River after man-made connection with the Tombigbee River in the mid 1980s. A subsequent decline in the distribution and abundance of the native brook silverside (Labidesthes sicculus) led to speculation that dietary competition might be involved. I used extant data to test the null hypotheses that diets are not different between the two silverside species in TTW, that dietary overlap between them is random and that no dietary niche shift occurs for either species in the presence or absence of its putative competitor. I accomplished this by quantifying the diet of both species from sympatric and allopatric collections, then using multivariate statistics and null models to test for significant dietary differences, overlap, and niche shifts. The analysis indicated that diets differed significantly between the two species. However, dietary overlap at sites of co-occurrence was greater than expected under conditions of incipient competitive exclusion; and, dietary niche shifts were not found when the diet of either species in allopatric collections was compared to its diet in sympatric collections. Thus, there was no evidence for direct involvement of dietary competition in the population trends of silversides in the Tennessee-Tombigbee Waterway. Yet, it appears that M. audens is replacing L. sicculus in dominant habitats of TTW, just as has happened in other, similar systems. Simulations with STELLA� were used to estimate the degree of inter-specific competition that might account for observed rates of replacement. Results implied a 10 % ecological advantage of M. audens over L. sicculus.

I investigated dietary differences, overlap and shifts for two atherinid fish species inhabiting the highly modified Tennessee-Tombigbee Waterway (TTW) in Mississippi, U.S.A. The Mississippi silverside (Menidia audens) is now common throughout the waterway and apparently invaded from the Tennessee River after man-made connection with the Tombigbee River in the mid 1980s. A subsequent decline in the distribution and abundance of the native brook silverside (Labidesthes sicculus) led to speculation that dietary competition might be involved. I used extant data to test the null hypotheses that diets are not different between the two silverside species in TTW, that dietary overlap between them is random and that no dietary niche shift occurs for either species in the presence or absence of its putative competitor. I accomplished this by quantifying the diet of both species from sympatric and allopatric collections, then using multivariate statistics and null models to test for significant dietary differences, overlap, and niche shifts. The analysis indicated that diets differed significantly between the two species. However, dietary overlap at sites of co-occurrence was greater than expected under conditions of incipient competitive exclusion; and, dietary niche shifts were not found when the diet of either species in allopatric collections was compared to its diet in sympatric collections. Thus, there was no evidence for direct involvement of dietary competition in the population trends of silversides in the Tennessee-Tombigbee Waterway. Yet, it appears that M. audens is replacing L. sicculus in dominant habitats of TTW, just as has happened in other, similar systems. Simulations with STELLA� were used to estimate the degree of inter-specific competition that might account for observed rates of replacement. Results implied a 10 % ecological advantage of M. audens over L. sicculus.

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The purpose of this work is to create a sediment budget template (SBT) with Aberdeen Pool on the Tennessee-Tombigbee Waterway as the demonstration site. The first task is to define the sediment behavior for the system in question. USGS data are used for sediment concentrations and flows. The USGS data are the basis for the Power Curve Program which defines the sediment behavior in terms of a power function. The second program, Tier 1 Program, uses the power curve coefficients along with the bankfull discharge to define the sediment fluxes. Thirdly, the Tier 2 Program uses power curve coefficients with daily flows to calculate daily sediment flux which are integrated over each year to calculate the yearly fluxes. From the sediment fluxes, a mass balance equation is implemented to estimate total deposition. Lastly, the computer program SIAM is used to estimate deposition amount. Comparison among the three different methods provides a best estimate of the final depositional approximation.

Britain and Japan, fellow island nations, share many geographical similarities, and accordingly both societies have long taken advantage of water transport domestically. In modern times the two nations’ governments have diverged in terms of philosophies toward economy and industrialization. Britain is known as today’s consummate private-industry advocate within western Europe, while Japan is noted for the strong level of government “guidance” in its post-WWII economy. Using the abovementioned similarities as a baseline, this thesis examines how the supposedly different relationships between government and economy in Britain and Japan have affected the ongoing use of water in their domestic transport sectors since World War II. Some forms of water transport have continued to thrive commercially in both nations, due primarily to those forms’ inherent economic and technical advantages, while other water transport modes are maintained through government support because of other, less commercial benefits they offer to the two societies.

The introductory part of this thesis focuses on the detailed characteristics of the Danube region, on the Danube itself as well as on the ongoing international cooperation of involved Danubian countries. Next section contains a comprehensive analysis of the cargo inland waterway transport on the Danube in Austria with respect to historical development, present state of commodity transportation as well as with respect to facilities and performance of Austrian ports and accessibility of the Danube for cargo river ships during the year. The final part of this thesis deals with current problems of cargo river carriers on the Austrian part of the Danube and there are possible solutions to these problems as well. Attention is also paid to the importance of cargo inland waterway transport for the whole country.

No description available.

Thesis--University of Illinois. / Includes bibliographical references (p. 209-210).

Thesis--University of Illinois. / Bibliography: p. 209-210.