Louis A. Helfrich

Use of a Readers Survey to Evaluate Fisheries Education Publications

Demand for an effective way to evaluate natural resource education programs and materials is increasing. In this study, a mail questionnaire survey was developed to examine the impact on riparian landowners of a cooperative extension education publication addressing river conservation. Our respondents held a favorable opinion about this publication. The majority of readers surveyed found it understandable, well organized, attractive, interesting, persuasive, educational, and sufficiently useful to be kept for future reference. Most readers expressed a willingness-to-pay price that exceeded...

Year
1987

Profiles of Shenandoah River Anglers Fishing under Three Black Bass Length Limit Regulations

Fisheries Outstanding Technical Paper

An on-site interview and mail questionnaire survey of 409 anglers on the Shenandoah River, Virginia, was conducted to compare the characteristics, motivations, perceptions, and preferences of anglers fishing under 3 different minimum black bass length limit regulations (no size limit, a 279-330 mm slot length limit, and a 305 mm minimum limit). Considerable uniformity was found in the 3 regulation areas in harvest behavior, equipment expenditures, perceptions of fish quality (size), components of fishing enjoyment, motivations for fishing, and fisheries management and regulation...

Year
1987

Use of Seafood Processing Wastes (Blue Crab and Herring Scrap) as Protein Substitutes in Rainbow Trout Diets

Laboratory and field growth trials were conducted to determine the feasibility of using blue crab (Callinectes sapidus) or Atlantic herring (Clupea harenous) cannery waste as dietary protein substitutes in pelleted rainbow trout (Salmo gairdneri) feeds. In lab and field experiments, triplicate groups of trout were fed 3 nutritionally complete diets: (1) a commercial diet (38.8% protein); or 1 of 2 experimental diets containing either (2) blue crab scrap (35.9% protein) or (3) herring byproducts (33.9% protein). Complete replacement of conventional fish meal as a protein source in rainbow...

Year
1984

Agonistic Behavior, Social Dominance, and Food Consumption of Brook Trout and Rainbow Trout in a Laboratory Stream

Agonistic behavior and social dominance relationships between similar-sized, wild, adult brook trout (Salvelinus fontinalis) and rainbow trout (Salmo gairdneri) were examined in a laboratory stream. Frequency of movements, aggressive encounters, and consumption of food items by trout when held as single specimens, intraspecific pairs, and interspecific pairs were compared. Rainbow trout were more mobile, aggressive, and successful foragers on drifting prey than brook trout; however, neither species appeared to possess a competitive advantage in establishing social dominance or displacing...

Year
1982

Commercial Aquaculture In Virginia In 1978

In 1978, all commercial aquaculture enterprises operating in the state were surveyed by telephone and in person to determine the status of the industry and to assess the biological and economic feasibility of rearing aquatic organisms for profit in Virginia. A total of II commercial aquaculture firms were in business during 1978. Six establishments were producing rainbow trout (Salmo gairdneri) for food and stocking recreational waters, 2 were rearing warmwater sport fish fingerlings and bait fish, and 3 were culturing clams. In contrast to most southern states, no commercial producers in...

Year
1979

Extent And Severity Of Avian Predation At Federal Fish Hatcheries In The United States

A survey of Federal fish hatcheries in the United States was conducted to determine the extent and severity of avian predation on fish stocks as well as to determine which avian species were the most serious predators. A list of 58 bird species in 14 families was provided. Managers of hatcheries were asked to indicate which species or members of what family caused problems by predation in their hatcheries. They were asked to provide their estimate of the severity of the problem; i.e. severe, significant, trivial, or none. They were also asked which fish species were preyed upon and also to...

Year
1978

Effects Of Rotenone On Macrobenthic Invertebrates Of A Pennsylvania Stream

Although the use of rotenone as a fish toxicant is a common freshwater fisheries management technique, little is known of its effect on stream invertebrates. In this study pre- and post-treatment bottom samples of benthic invertebrates, collected from 4 study stations, were compared to determine the short-term effects of rotenone. Continuous drift sample~ collected throughout the treatment period provided additional qualitative information on the vulnerability of the benthic invertebrates to the toxin. Of the 4 major orders of macrobenthic invertebrates represented in Sinking Creek (...

Year
1978