Geology topics

Robert F. Gaugush

Publications and source records attributed to Robert F. Gaugush.

4 recordsLinked to original sources

USGS2015

Response of Bighead Carp and Silver Carp to repeated water gun operation in an enclosed shallow pond

The Bighead Carp Hypophthalmichthys nobilis and Silver Carp H. molitrix are nonnative species that pose a threat to Great Lakes ecosystems should they advance into those areas. Thus, technologies to impede Asian carp movement into the Great Lakes are needed; one potential technology is the seismic water gun. We evaluated the efficacy of a water gun array as a behavioral deterrent to the movement of acoustic-tagged Bighead Carp and Silver Carp in an experimental pond. Behavioral responses were evaluated by using four metrics: (1) fish distance from the water guns ( D ); (2) spatial area of the fish's utilization distribution (UD); (3) persistence velocity ( V p ); and (4) number of times a fish transited the water gun array. For both species, average D increased by 10 m during the firing period relative to the pre-firing period. During the firing period, the spatial area of use within the pond decreased. Carp were located throughout the pond during the pre-firing period but were concentrated in the north end of the pond during the firing period, thus reducing their UDs by roughly 50%. Overall, V p decreased during the firing period relative to the pre-firing period, as fish movement became more tortuous and confined, suggesting that the firing of the guns elicited a change in carp behavior. The water gun array was partially successful at impeding carp movement, but some fish did transit the array. Bighead Carp moved past the guns a total of 78 times during the pre-firing period and 15 times during the firing period; Silver Carp moved past the guns 96 times during the pre-firing period and 13 times during the firing period. Although the water guns did alter carp behavior, causing the fish to move away from the guns, this method was not 100% effective as a passage deterrent.

North American Journal of Fisheries Management↗

USGS2004

A suspended sediment budget for Pool 13 and La Grange Pool of the upper Mississippi River system

The suspended sediment budget for Pool 13 of the Mississippi River and La Grange Pool of the Illinois River was examined over a 3-yr period (October 1995 through September 1997). Pool 13 output was between 3.07 and 3.64 million t (metric tons) of suspended sediment annually during the study period. Loads to Pool 13 were dominated by those delivered by the Mississippi River (76%, 74%, and 66% in the 1995, 1996, and 1997 water years, respectively). Pool 13 exhibited sediment export (output greater than input) in 1995, a balance in 1996, and marked sediment trapping (output less than input) in 1997. Within the three study years, Pool 13 received its highest water and sediment loads during spring (March through May) and this period was marked by sediment export. Suspended sediment loads were trapped during the remainder of the year. La Grange Pool output was between 3.71 and 5.04 million t of suspended sediment annually during the 1995-97 water years. The Illinois River accounted for less than 50% of the suspended sediment load to the pool (19%, 25%, and 45% in the 1995, 1996, and 1997 water years, respectively. La Grange Pool exhibited considerable sediment trapping in 1995 whereas the 1996 and 1997 water years were much closer to a balance wherein output was within 5% of input. Generally, La Grange Pool received its largest water and sediment loads during the late spring—early summer period (April through June), but in 1997 the late winter loads predominated. In all years, La Grange Pool trapped the sediments during these high discharge, high loading periods and exported suspended sediments for the remainder of the year. The distinct differences in the manner in which these pools process suspended sediment loads may be related to the considerable differences between the morphometry of these pools.

Illinois, Iowa↗

USGS1998

Estimating flow rates to optimize winter habitat for centrarchid fish in Mississippi River (USA) backwaters

The backwaters of large rivers provide winter refuge for many riverine fish, but they often exhibit low dissolved oxygen levels due to high biological oxygen demand and low flows. Introducing water from the main channel can increase oxygen levels in backwaters, but can also increase current velocity and reduce temperature during winter, which may reduce habitat suitability for fish. In 1993, culverts were installed to introduce flow to the Finger Lakes, a system of six backwater lakes on the Mississippi River, about 160 km downstream from Minneapolis, Minnesota. The goal was to improve habitat for bluegills and black crappies during winter by providing dissolved oxygen concentrations >3 mg/L, current velocities <1 cm/s, and temperatures >1°C. To achieve these conditions, we used data on lake volume and oxygen demand to estimate the minimum flow required to maintain 3 mg/L of dissolved oxygen in each lake. Estimated flows ranged from 0.02 to 0.14 m 3 /s among lakes. Data gathered in winter 1994 after the culverts were opened, indicated that the estimated flows met habitat goals, but that thermal stratification and lake morphometry can reduce the volume of optimal habitat created.

Mississippi River↗

USGS1996

Hydrologic modification to improve habitat in riverine lakes: Management objectives, experimental approach, and initial conditions

The Finger Lakes habitat-rehabilitation project is intended to improve physical and chemical conditions for fish in six connected back water lakes in Navigation Pool 5 of the upper Missouri River. The primary management objective is to improve water temperature, dissolved oxygen concentration and current velocity during winter for bluegills, Lepomis macrochirus, and black crappies, Pomoxis nigromaculatus, two of the primary sport fishes in the lakes. The lakes will be hydrologically altered by Installing culverts to Introduce controlled flows of oxygenated water into four lakes, and an existing unregulated culvert on a fifth lake will be equipped with a control gate to regulate inflow. These habitat modifications constitute a manipulative field experiment that will compare pre-project (1991 to summer 1993) and post-project (fall 1993 to 1996) conditions in the lakes, including hydrology, chemistry, rooted vegetation, and fish and macroinvertebrate communities. Initial data indicate that the Finger Lakes differ in water chemistry, hydrology, and macrophyte abundance. Macroinvertebrate communities also differed among lakes: species diversity was highest in lakes with dense aquatic macrophytes. The system seems to support a single fish community, although some species concentrated in individual lakes at different times. The introduction of similar flows into five of the lakes will probably reduce the existing physical and chemical differences among lakes. However, our ability to predict the effects of hydrologic modification on fish populations is limited by uncertainties concerning both the interactions of temperature, oxygen and current in winter and the biological responses of primary and secondary producers. Results from this study should provide guidance for similar habitat-rehabilitation projects in large rivers.

Book chapter↗