Michael C. Quist

Proposed Standard Weight (Ws) Equations and Standard Length Categories for 18 Warmwater Nongame and Riverine Fish Species

Abstract Relative weight (W r) is one of several condition indices used to assess the general health of fishes. Standard weight (W s) equations are required to calculate W r, but are unavailable for many nongame and riverine fish species. Therefore, we developed W s equations for the following taxa: longnose gar Lepisosteus osseus, spotted gar L. oculatus, common carp Cyprinus carpio, bigmouth buffalo Ictiobus cyprinellus, river carpsucker Carpiodes carpio, shorthead redhorse Moxostoma macrolepidotum, smallmouth buffalo I. bubalus, white sucker Catostomus commersoni, black bullhead Ameiurus melas, brown bullhead A. nebulosus, flathead catfish Pylodictis olivaris, white catfish A. catus, yellow bullhead A. natalis, white perch Morone americana, yellow bass M. mississippiensis, green sunfish Lepomis cyanellus, rock bass Ambloplites rupestris, and warmouth L. gulosus. These W s equations were evaluated with statistical validation approaches similar to previously defined regression-line-percentile equations. ...

Military training effects on terrestrial and aquatic communities on a grassland military installation

Understanding the link between terrestrial and aquatic systems is important because disturbance to terrestrial systems may also influence stream processes. Military training lands provide a unique opportunity to examine the influence of large-scale disturbance on terrestrial and aquatic communities in the absence of other anthropogenic disturbances (e.g., agriculture, urbanization). The objective of this study was to determine the effects of past mechanized infantry training on terrestrial and aquatic ecosystem properties on Fort Riley Military Reservation in northeastern Kansas. We used a long-term data set and supplemental study plots to determine the effects of military training use on terrestrial systems. Headwater and middle stream reaches were also sampled to determine the effects of watershed training use on habitat and fish community structure. High military training use was associated with increased bare soil, reduced total plant cover, and compositional shifts in plant communities. Reduced cover of perennial, matrix-forming grasses and native species, and increased cover of annuals and introduced species were also associated with high training activity. High military training use in study watersheds was associated with increased sediment in pools and riffles and reduced abundance of benthic insectivores, herbivore–detritivores, and silt-intolerant species. Sites in watersheds receiving high training use were also characterized by an abundance of trophic generalists and tolerant species. Our results suggest that military training activities had significant ecological effects on the properties of terrestrial and aquatic ecosystems, both with respect to recovery from past disturbance and resilience to future disturbance. Corresponding Editor: M. G. Turner.

Potential Influence of Harvest on Shovelnose Sturgeon Populations in the Missouri River System

Abstract The collapse of the European and Asian caviar industry has raised concern about the overexploitation of shovelnose sturgeon Scaphirhynchus platorynchus in the Missouri River. Unfortunately, little is known about the potential effects of harvest on the population dynamics of this species. Therefore, this study was conducted to describe the population characteristics (e.g., growth, longevity, and mortality) and to determine the influence of exploitation and harvest regulations (minimum length limits) on the yield, size structure, and egg production of shovelnose sturgeon from three sites in the Missouri River using a Beverton–Holt equilibrium model. Despite differences in the population characteristics (e.g., growth and longevity) of shovelnose sturgeon among sites, all populations responded similarly to harvest at the conditional natural mortality rates (death rate in the absence of harvest) used in our simulations (i.e., 5% and 20%). Our simulations of yield indicated that growth overfishing (i.e...

A Technique for Preparing Fin Rays and Spines for Age and Growth Analysis

Abstract Fin rays and spines are becoming more popular for age and growth analysis. A protocol for processing structures is first to mount the structure in epoxy, then to use a low-speed saw or handsaw to section the structure, and finally to estimate age from the resulting section. Unfortunately, scientists are often unaware of efficient techniques for mounting structures for such analyses. We describe a simple technique for mounting fin rays and spines in epoxy in preparation for sectioning. The advantages of this method include minimal preparation time, low cost, and little or no damage to hard structures. We have used this technique extensively to estimate age from the fin rays and spines of shovelnose sturgeon Scaphirhynchus platorynchus, catostomids, cyprinids, and ictalurids; however, this technique is useful for any species for which fin rays or spines are used in age and growth analyses. In addition, the technique is not limited to fin rays and spines; it can also be used to prepare a variety of ...

Relations among Habitat Characteristics, Exotic Species, and Turbid-River Cyprinids in the Missouri River Drainage of Wyoming

Abstract We used data from 91 stream reaches in the Missouri River drainage of Wyoming to determine whether abiotic and biotic factors were related to the abundance of four cyprinid species associated with turbid-river environments: flathead chub Platygobio gracilis, sturgeon chub Macrhybopsis gelida, plains minnow Hybognathus placitus, and western silvery minnow H. argyritis. The abundance of these cyprinids was positively related to the percentage of fine substrate in a reach and inversely related to the percentage of gravel substrate, the percentage of large rocky substrate, and the abundance of exotic piscivores. Differences in substrate composition and abundance of exotic piscivores were largely explained by the presence and location of large, main-stem impoundments. Reaches without any large impoundments in their watershed had a high percentage of fine substrate, high catch rates of turbid-river cyprinids, few exotic piscivores, and little gravel or large rocky substrate. Reaches with a downstream i...

Latitudinal Comparisons of Walleye Growth in North America and Factors Influencing Growth of Walleyes in Kansas Reservoirs

Abstract We compared the growth of walleyes Stizostedion vitreum in Kansas to that of other populations throughout North America and determined the effects of the abundance of gizzard shad Dorosoma cepedianum and temperature on the growth of walleyes in Kansas reservoirs. Age was estimated from scales and otoliths collected from walleyes (N = 2,072) sampled with gill nets from eight Kansas reservoirs during fall in 1991-1999. Age-0 gizzard shad abundance was indexed based on summer seining information, and temperature data were obtained from the National Oceanic and Atmospheric Administration. Parameter estimates of von Bertalanffy growth models indicated that the growth of walleyes in Kansas was more similar to that of southern latitude populations (e.g., Mississippi and Texas) than to that of northern (e.g., Manitoba, Minnesota and South Dakota) or middle latitude (e.g., Colorado and Iowa) populations. Northern and middle latitude populations had lower mean back-calculated lengths at age 1, lower growth...

Common carp (Cyprinus carpio), sport fishes, and water quality: Ecological thresholds in agriculturally eutrophic lakes

Abstract We examined fish populations, limnological conditions, lake basin morphology and watershed characteristics to evaluate patterns in population characteristics of ecologically important fish species in relation to environmental conditions in agriculturally eutrophic lake systems. Fish populations and environmental characteristics were sampled from 129 Iowa lakes using standard techniques from 2001–2006. Lakes with high catch rates of common carp (Cyprinus carpio) had high nutrient concentrations, high phytoplankton biomass and low water transparency. In addition, lakes with high catch rates of common carp had low catch rates of important sport fishes including bluegill (Lepomis macrochirus), largemouth bass (Micropterus salmoides), black crappie (Pomoxis nigromaculatus) and white crappie (P. annularis). The relationship between common carp and sport fishes appeared to function as an ecological threshold. Specifically, when common carp catch rates were > 2 kilograms per fyke net night, catch rates of sport fish were always low and water quality in the study lakes was poor. Shallow systems (natural lakes, oxbows) had higher densities of common carp compared to deeper systems (impoundments, surface mines), thereby suggesting that shallow lakes are most sensitive to the effects of common carp and that restoration efforts incorporating biomanipulation of common carp will likely be most successful in shallow systems.

Assemblage and Population-Level Responses of Stream Fish to Riparian Buffers at Multiple Spatial Scales

Abstract Riparian buffers can improve stream water and habitat quality by reducing non-point-source pollution (e.g., nutrients and sediment), increasing canopy cover and thereby reducing water temperature, and contributing allochthonous organic matter (e.g., leaf litter and woody debris). However, the influence of riparian buffers on biotic assemblages in streams is poorly understood, particularly in the Midwestern United States. In this study, we evaluated the effects of riparian buffers on instream habitat, fish assemblage structure, and population characteristics (i.e., the growth of two small-bodied species) in three streams in central Iowa. The streams were surveyed at two spatial scales; specifically, 41 reaches were sampled and 247 macrohabitat types (i.e., pool, riffle, and run) were subsampled in the summer of 2007. Fish assemblage structure data were summarized into separate data sets by the relative abundance of individual species (i.e., fish per minute of electrofishing) and guilds (e.g., trop...

Standard Weight (Ws ) Equation and Length Categories for Shovelnose Sturgeon

Abstract Weight–length data were compiled from 32 populations of shovelnose sturgeon Scaphirhynchus platorynchus (N = 11,820) from nine states within the geographic distribution of the species. We used the regression-line-percentile technique, which provides a 75th-percentile standard, to develop the standard weight (Ws ) equation. The proposed equation in metric units is log10 Ws = −6.287 + 3.330 log10FL; Ws is weight in grams and FL is fork length in millimeters. The equivalent equation in English units is log10 Ws = −4.266 + 3.330 log10FL; Ws is weight in pounds and FL is fork length in inches. These equations are proposed for use with shovelnose sturgeon between 120 mm (5 in) and 1,050 mm (41 in). Values for relative weight (Wr ) calculated with the Ws equation did not consistently increase or decrease with increasing fish length, indicating absence of length bias. We propose the following length categories for calculation of proportional stock density (PSD) and relative stock densities (RSDs): stock,...

Influences of Fragmentation on Three Species of Native Warmwater Fishes in a Colorado River Basin Headwater Stream System, Wyoming

Abstract We investigated the effects of constructed instream structures on movements and demographics of bluehead suckers Catostomus discobolus, flannelmouth suckers C. latipinnis, and roundtail chub Gila robusta in the upstream portion of Muddy Creek, an isolated headwater stream system in the upper Colorado River basin of Wyoming. Our objectives were to (1) evaluate upstream and downstream movements of these three native species past a small dam built to divert irrigation water from the stream and a barrier constructed to prevent upstream movements of nonnative salmonids and (2) describe population characteristics in stream segments created by these structures. Our results indicated that upstream and downstream movements of the three target fishes were common. Fish of all three species moved frequently downstream over both structures, displayed some upstream movements over the irrigation diversion dam, and did not move upstream over the fish barrier. Spawning migrations by some fish into an intermittent...