River Size and Fish Assemblages in Southwestern South Dakota

We studied relations between river size, fish species diversity, and fish species composition along four major rivers in the Great Plains of southwestern South Dakota to assess patterns of species diversity and composition. We expected diversity to increase with river size and fish composition to change via species addition downstream. Previous surveys of 52 sampling stations provided fish assemblage data, and we used the Geographic Information System (GIS) to determine watershed area by station. Watershed area did not predict species richness or species diversity (Fisher's a), so species richness of 12 ± 3.5 SD species and Fisher's a of 2.3 ± 0.87 SD characterized species diversity in the study area. Cluster analysis of faunal similarity (Sorensen's Index) among the 52 sampling stations identified two geographically distinct faunal divisions, so species composition was variable within the study area, but changed via species replacements among faunas rather than species additions downstream. Nonnative species were a minor component of all faunas. Uniform species diversity may be a recent phenomenon caused by impacts of Missouri River dams on native large-river fishes and the unsuitability of rivers in the Great Plains for nonnative species. Variation in faunal composition may also be recent because it was affected by dams.

Diets of Baird’s Beaked Whales, Berardius bairdii, in the Southern Sea Of Okhotsk and Off the Pacific Coast Of Honshu, Japan

Stomach contents were analyzed from 127 Baird’s beaked whales, Berardizls bairdii, taken in coastal waters of Japan. During late July-August of 1985- 1987, 1989, and 1991, 107 samples were collected from off the Pacific coast of Honshu. An additional 20 samples were collected from whales taken in the southern Sea of Okhotsk during late August-September of 1988 and 1989. Prey identification using fish otoliths and cephalopod beaks revealed the whales fed primarily on deep-water gadiform fishes and cephalopods in both regions. Prey species diversity and the percentage of cephalopods and fish differed between the two regions. Off the Pacific coast of Honshu the whales fed primarily on benthopelagic fishes (81.8%) and only 18.0% on cephalopods. Eight species of fish representing two families, the codlings (Moridae) and the grenadiers (Macrouridde), collectively made up 81.3% of the total. Thirty species of cephalopods representing 14 families made up 12.7%. In the southern Sea of Okhotsk, cephalopods accounted for 87.1% of stomach contents. The families Gonatidae and Cranchiidae were the predominant cephalopod prey, accounting for 86.7% of the diet. Gadiform fish accounted for only 12.9% of the diet. Longfin codling, Laernonma longipes, was the dominant fish prey in both regions. Depth distribution of the two commonly consumed fish off the Pacific coast of Honshu indicate the whales in this region fed primarily at depths ranging from 800 to 1,200 m.

Simulations of Ground-Water Flow, Transport, Age, and Particle Tracking near York, Nebraska, for a Study of Transport of Anthropogenic and Natural Contaminants (TANC) to Public-Supply Wells

The U.S. Geological Survey (USGS) is committed to providing the Nation with credible scientific information that helps to enhance and protect the overall quality of life and that facilitates effective management of water, biological, energy, and mineral resources (http://www.usgs.gov/). Information on the Nation’s water resources is critical to ensuring long-term availability of water that is safe for drinking and recreation and is suitable for industry, irrigation, and fish and wildlife. Population growth and increasing demands for water make the availability of that water, now measured in terms of quantity and quality, even more essential to the long-term sustainability of our communities and ecosystems. The USGS implemented the National Water-Quality Assessment (NAWQA) Program in 1991 to support national, regional, State, and local information needs and decisions related to water-quality management and policy (http://water.usgs.gov/nawqa). The NAWQA Program is designed to answer: What is the condition of our Nation’s streams and ground water? How are conditions changing over time? How do natural features and human activities affect the quality of streams and ground water, and where are those effects most pronounced? By combining information on water chemistry, physical characteristics, stream habitat, and aquatic life, the NAWQA Program aims to provide science-based insights for current and emerging water issues and priorities. From 1991-2001, the NAWQA Program completed interdisciplinary assessments and established a baseline understanding of water-quality conditions in 51 of the Nation’s river basins and aquifers, referred to as Study Units (http://water.usgs.gov/nawqa/studyu.html).

A Rubber Band Around an Atlantic Croaker

A rubber band permanently girdled an Atlantic croaker, Micropogon undulatus, resulting in considerable malformation and pathological alterations of the fish. On 12 July 1973 at Graveline Bayou, Jackson County, Mississippi, Mrs. Buster Blades caught on hook and line a 175 mm standard length (102.1 g) croaker that she immediately separated from the rest of her catch as a suspected parasitized fish. Later upon closer examination, she realized that a rubber band encircled the fish, and so she brought the fish to us. The band had deformed the prepelvic isthmus, restricted movement of the pectoral fins, and permanently encircled the fish through a hole in the dorsum. Much of the elasticity was lost, but the band was entire and free to rotate through the perforation below the first dorsal fin. The tissue above the perforation, including the tissue of the dorsal fin, was complete and not severed, although several scales were regenerated. These observations, in addition to the malformed ventral area, suggest a lengthy association between band and fish.

ACTIVITY OF LM 2219 (DIFETHIALONE), A NEW ANTICOAGULANT RODENTICIDE, IN COMMENSAL RODENTS

ABSTRACT: Preliminary studies completed on commensal rodents with the new anticoagulant rodenticide difethialone showed very good efficacy, such that 25 ppm baits could be used effectively. New test results presented in this publication confirm the activity as shown under laboratory conditions in choice tests, which represent more severe conditions, as well as its effectiveness against rodents that are resistant and non-resistant to warfarin. In tests where the palatability was only fair the chemical activity resulted in excellent mortality. In a field test against a large population of Mus musculus the results proved very satisfactory. Difethialone is toxic to birds and fish. However, it seems to be better tolerated by dogs and pigs, animals that are frequently on the list of accidental poisonings. Difethialone is stored over a prolonged period in the liver but the risk to non-target species consuming rodents having ingested the compound does not seem to be high. For reasons attributed to the mode of action, difethialone must be handled with precautions as other anticoagulants for which Vitamin Kj is the antidote. In the event of an accidental poisoning, an antidotal therapy plan is proposed. The lower levels of active ingredient in finished baits (25 ppm) should pose a low risk to non-target species.

THE HANDBOOK OF WILDLIFE DEPREDATION TECHNIQUES: A SYNOPSIS

In 1979, the Game Division Administration of the Wyoming Game and Fish Department (WGFD) appointed John Demaree and Tim Fagan to develop a handbook that would address the ever increasing problem of wildlife depredation. Field personnel were often times at a loss on how to deal with or evaluate the assorted types of damage situations they were encountering. Because Wyoming requires landowners to be reimbursed for damage done by big and trophy game and game birds to their crops and livestock, an evaluation and techniques handbook was desperately needed. The initial handbook, completed in January 1981, was 74 pages, and both John and I considered it a masterpiece. It did not take long, however, for this handbook to become somewhat lacking in information and outdated. In 1990, our administration approached us again asking this time for an update of our ten-year-old handbook. John and I went to work, and with the assistance of Evin Oneale of the Wyoming Cooperative Fish and Wildlife Research unit, and Bill Hepworth and John Schneidmiller of the WGFD, have just completed the second edition. This edition is over 600 pages and titled "The Handbook of Wildlife Depredation Techniques." Neither of us care to be around when a third edition is needed. In this handbook we have attempted to cover any type of damage situation our personnel may encounter. Although the primary function of this manual is to inform department personnel about proper and uniform damage prevention and evaluation techniques, it also provides relative and pertinent information concerning the many aspects of wildlife depredation. Information for this handbook has been compiled from techniques developed by our personnel, personnel from other states and provinces, and published data on wildlife depredation. There are nine chapters, a reprint, and Appendix section in this handbook. We will briefly summarize each chapter regarding its contents.