Epizootics among chinook salmon fingerlings at the Coleman National Fish Hatchery have occurred periodically since 1941. A virus or virus-like filterable agent has been demonstrated to be the causative agent of this disease.

Authors

A. J. Ross, R.R. Rucker

Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Eastern Ecological Science Center, Western Fisheries Research Center

January 1, 1960

Skin lesions on black ducks and mallards caused by chigger (Wormsia strandtmani Wharton 1947)

No abstract available.

Authors

G. M. Clark, Vernon D. Stotts

Ecosystems Mission Area, Eastern Ecological Science Center

January 1, 1959

Study and interpretation of the chemical characteristics of natural water

The chemical composition of natural water is derived from many different sources of solutes, including gases and aerosols from the atmosphere, weathering and erosion of rocks and soil, solution or precipitation reactions occurring below the land surface, and cultural effects resulting from activities of man. Some of the processes of solution or precipitation of minerals can be closely evaluated by

Authors

John David Hem

Water Resources Mission Area, Dakota Water Science Center, Ohio-Kentucky-Indiana Water Science Center

January 1, 1959

Report of state-wide bird count, May 2, 1959

No abstract available.

Authors

C.S. Robbins

Ecosystems Mission Area, Eastern Ecological Science Center

January 1, 1959

Parasites of the Raccoon, Procyon lotor

At least 76 species of parasites have been reported from raccoons. These include 4 species of protozoa, 27 nematodes, 20 trematodes, 7 cestodes, 3 acanthocephala, and 15 arthropods. In many cases these represent single reports. In other cases some of the parasites are known to be of frequent occurrence and broad geographical range on the basis of several surveys that have been conducted. During

Authors

G. M. Clark, C. M. Herman

Ecosystems Mission Area, Eastern Ecological Science Center

January 1, 1959