Harold L. Schramm

Evaluation of a Statewide Volunteer Angler Diary Program for Use as a Fishery Assessment Tool

Abstract We implemented a statewide volunteer angler diary program for the 1995 fishing season to determine whether angler diaries can provide data that are useful for the management of the principal sport fishes in waters throughout Mississippi. Of 1,153 anglers volunteering to participate, 224 (19%) returned diaries with at least one recorded fishing trip that was usable for data analysis. We found no significant (P < 0.05) correlations between angler diary catch per unit effort (CPUE; fish/h) and creel survey or electrofishing CPUE for black bass Micropterus spp. and crappies Pomoxis spp. The length distributions of black bass reported by anglers were similar to those obtained from electrofishing samples at five of seven reservoirs when fish smaller than 250 mm were excluded from the comparisons. The length distributions of crappies obtained from diary reports were different from those obtained from electrofishing samples. Low participation by anglers for catfish (Ictaluridae) and sunfish Lepomis spp. ...

Ecosystem Management: Implications for Fisheries Management

Abstract A panel of nine professional fish and wildlife scientists presented their views and exchanged ideas regarding ecosystem management during a symposium held in August 1995 at the American Fisheries Societys annual meeting in Tampa, Florida. The panelists agreed many fisheries resources are declining, and management efforts are not succeeding; natural resource management is increasing in complexity; and a change in management philosophy is needed. The panel agreed that ecosystem management is an evolution of management philosophy that focuses on local and large geographic scales, considers long-term temporal scales, and preserves biotic and abiotic components of ecosystems when making natural resource management decisions. They noted that the philosophy of ecosystem management considers human values and requires collaboration among government agencies, private property owners, and a wide array of stakeholders when making management decisions. The panel also identified a need for enhanced education ...

Nutrient dynamics in the lower Mississippi River floodplain: Comparing present and historic hydrologic conditions

Alterations to the lower Mississippi River-floodplain ecosystem to facilitate commercial navigation and to reduce flooding of agricultural lands and communities in the historic floodplain have changed the hydrologic regime. As a result, the flood pulse usually has a lower water level, is of shorter duration, has colder water temperatures, and a smaller area of floodplain is inundated. Using average hydrologic conditions and water temperatures, we used established nitrogen and phosphorus processes in soils, an aquatic ecosystem model, and fish bioenergetic models to provide approximations of nitrogen and phosphorus flux in Mississippi River flood waters for the present conditions of a 2-month (mid-March to mid-May) flood pulse and for a 3-month (mid-March to mid-June), historic flood pulse. We estimated that the soils and aquatic biota can remove or sequester 542 and 976 kg nitrogen ha−1 during the present and historic hydrologic conditions, respectively. Phosphorus, on the other hand, will be added to the water largely as a result of anaerobic soil conditions but moderated by biological uptake by aquatic biota during both present and historic hydrologic conditions. The floodplain and associated water bodies may provide an important management opportunity for reducing downstream transport of nitrogen in Mississippi River waters.

Effects of Cover and Prey Size on Preferences of Juvenile Largemouth Bass for Blue Tilapias and Bluegills in Tanks

Abstract The effects of vegetative cover and relative size of prey were tested on the forage preference of juvenile largemouth bass Micropterus salmoides offered blue tilapias Tilapia aurea and bluegills Lepomis macrochirus in laboratory electivity experiments. When offered forage at or near the maximum consumable size in tanks without vegetative cover, largemouth bass preferred bluegills, but consumed blue tilapias in the presence of vegetation. When offered forage smaller than the maximum consumable size in tanks without vegetation, largemouth bass selected blue tilapias. Differences between the forage species in body morphology and effective use of protective cover apparently caused the changes in prey selection. Our results suggest blue tilapias may be a suitable forage for largemouth bass, but that habitat characteristics and relative size distributions of other available forage may affect their use.

The Importance of Environmental Quality and Catch Potential to Fishing Site Selection by Freshwater Anglers in Mississippi

Abstract We measured the importance of 24 fishing site attributes to Mississippi freshwater anglers. Factor analysis identified four multiattribute factors as important in the selection of fishing location: CLEAN ENVIRONMENT, CATCH, COST AND HARVEST, and AMENITIES AND SAFETY. In general, the importance of site selection factors differed little among anglers grouped by preferred type of fish, preferred fishing location (lakes and reservoirs, rivers and streams, ponds, or reservoir tailwaters), usual manner of fishing (engine-powered boat, nonpowered boat, or shore), or change in fishing frequency. COST AND HARVEST was more important to anglers with high harvest orientations. We found low correlations between site selection factor importance scores and angler age, fishing frequency, fishing expenditures, or fishing motivation factors. We suggest that the general lack of differences in site selection factors among angler groups indicates that management strategies to improve fishing site attributes should be...

Evaluation of Procedures for Back-Calculation of Lengths of Largemouth Bass Aged by Otoliths

Abstract Back-calculation techniques for estimating fish lengths at previous ages have been evaluated for measurements from scales; however, there has been no evaluation of mathematical methods for back-calculating lengths from otoliths. Samples of Florida largemouth bass Micropterus salmoides floridanus from five lakes were aged by otoliths and used to compare fish lengths at previous ages estimated by three back-calculation techniques–direct proportion, intercept-corrected direct proportion, and regression. The direct proportion method provided the most reliable estimates of fish lengths at previous ages when otoliths were used. Lengths at previous ages back-calculated from the most recently formed annuli were similar to lengths back-calculated from earlier annuli of older fish.

Issues, benefits, and problems associated with fishing tournaments in inland waters of the United States : A survey of fishery agency administrators

Abstract A web-based survey was administered to state fisheries agency administrators in 2005 to assess and prioritize the impacts of tournament fishing on management of inland fishery resources. Surveys were completed by fishery administrators of 48 state agencies and the District of Columbia. Respondents rated tournaments as neither strongly benefiting nor adversely affecting fishery management. Benefits of tournaments to fishery management grouped into four factors (in order of decreasing impact) characterized as enhancing fishery management agency effectiveness, stimulating interest in fishing and fishery resources, measuring economic value, and collecting biological information. Adverse impacts grouped into six factors (in order of decreasing impact), characterized as resource crowding, user-group conflicts, costs of tournaments to fishery agencies, non-traditional uses of fisheries resources, fish introductions, and adverse affects on fish populations. Tournament issues and impacts generally did not...

Effects of Live-Well Conditions on Mortality and Largemouth Bass Virus Prevalence in Largemouth Bass Caught during Summer Tournaments

Abstract We evaluated the effect of improved live-well conditions and the interaction of tournament stress and largemouth bass virus (LMBV) on tournament-associated mortality of largemouth bass Micropterus salmoides caught during 12 summer tournaments. Improvements in live-well conditions (reduction in water temperature by 2–5°C; addition of NaCl; continuous aeration) significantly reduced initial mortality of largemouth bass from 7% to 3% (F 1,11 = 10.29, P < 0.01). However, postrelease mortality of fish held for 5 d in net-pens or raceways was not reduced by the improved live-well conditions and averaged 76% for all tournament fish (F 1,11 = 0.09, P = 0.77). The percentage of angler-caught fish infected with LMBV at the end of tournaments (14%) was significantly higher (P = 0.05) than the percentage infected in the general population (7%). The percentage of LMBV-infected fish increased during the post-tournament retention period to 64% for fish from live wells with improved conditions and 70% for fish f...

Factors Associated with Mortality of Walleyes and Saugers Caught in Live-Release Tournaments

Abstract We measured the initial mortality (fish judged nonreleasable at weigh-in), prerelease mortality (fish judged nonreleasable 1–2 h after weigh-in [which includes initial mortality]), and postrelease mortality (fish that died during a 5-d retention in net-pens) in 14 live-release tournaments for walleye Sander vitreus conducted in April–October 2006 and April–July 2007 in lakes and rivers in Michigan, Minnesota, North Dakota, South Dakota, and Wisconsin. Among the 14 events, initial mortality was 0–28%, prerelease mortality was 3–54%, and postrelease mortality was 0–100%; the mortality of reference fish (walleyes ≥31 cm long that were captured by electrofishing and held in net-pens with tournament-caught walleyes to measure postrelease mortality) was 0–97%. Mortality was generally low in events conducted when water temperatures were below 14°C but substantially higher in events when water temperatures were above 18°C. The mortality of reference fish suggests that capture by electrofishing and minima...

Caloric Densities of Selected Fish Prey Organisms in the Lower Mississippi River

ABSTRACT Estimates of caloric density and associated variation were generated for several common species of fish prey in the lower Mississippi River. Estimates were derived for eight common fishes including gizzard shad (Dorosoma cepedianum), threadfin shad (D. petenense), blue catfish (Ictalurus furcatus), flathead catfish (Pylodictis olivaris), brook silverside (Labidesthes sicculus), freshwater drum (Aplodinotus grunniens), white bass (Morone chrysops), and bluegill (Lepomis macrochirus) and for two decapod species, the giant river prawn (Macrobrachium ohioni) and a Procambarus crayfish species. Generated values for gizzard shad and bluegill were comparable to literature values; values for the other fishes and the two decapods have not been reported previously. Seasonal trends in caloric density were evident for blue catfish and gizzard shad. Though caloric content peaked at different times of the year for each species, values were consistently most variable during spring for both species.