body injury, stress, suffocation, water pollution, weather, and other - PDF document

body injury, stress, suffocation, water pollution, weather, and other reasons.A few dead �sh �oating on the surface of a pond or �sh to die of old age, injury, winter starvation, or even post-spawning stress in the springtime. However, when large numbers of �sh of all sizes are found dead Sudden, large �sh kills in ponds are often the result of �sh suffocation caused by nightime oxygen depletion in the summer. Fish kills from oxygen depletion very rich (green water) ponds following: (1) the die-off of a large algae bloom, (2) the decay of water weeds (4) the runoff of livestock waste and other organics surface or at the pond inlet or edges. Large �sh may die �rst, but all sizes of �sh are usually affected. The chlorine, gasoline, fuel oil, ammonia fertilizer, acids, ponds, but can occur. In order to prevent �sh suffocation in fertile ponds:Prevent manure and animal waste runoff into the Treat only one-third of the pond surface each time Water quality tests Water quality tests are usually expensive, complicated, and may be inconclusive. A number of water samples a problem. Moreover, because pond water quality may water quality. Fish Kills: Their Causes and PreventionL. A. Helfrich, Extension Specialist and Professor, Department of Fisheries and Wildlife Sciences, Virginia TechStephen A. Smith, Associate Professor, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech www.ext.vt.eduProduced by Communications and Marketing, College of Agriculture and Life Sciences, Virginia Polytechnic Institute and State University, 2009Virginia Cooperative Extension programs and employment are open to all, regardless of race, color, national origin, sex, religion, age, disability, political beliefs, sexual orientation, or marital or family status. An equal opportunity/affirmative action employer. Issued in furtherance of Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, and the U.S. Department of Agriculture cooperating. Mark A. McCann, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg; Alma C. Hobbs, Administrator, 1890 Extension Program, Virginia State, Petersburg. 2 Fish Diseases and ParasitesFish are constantly exposed to a wide variety of diseases and parasites that occur in surface waters. Fish are subject to infection by disease-causing viruses, bacteria, and fungi. Fish are also parasitized by tapeworms, trematodes (grubs), nematodes (roundworms), leeches, and lice. Most of these organisms normally occur at low levels in farm ponds and in limited numbers on the �sh. Some parasitized �sh in a pond are not unusual. However, large numbers of infected �sh are cause for concern since slow growth, sterility, stunted populations, and massive �sh kills may result from extensive diseases Fortunately, �sh diseases and parasites seldom reach epidemic levels, and sudden, large �sh kills in farm suffering from diseases or parasites usually die slowly, a few �sh each day. Only in severe cases when �sh are Some early warning symptoms of �sh suffering from on the head, body, and �ns. Sick �sh look and act waters. Sick �sh can be effectively treated in hatcheries and aquariums under controlled conditions. However, the �sh. Therefore, pond owners should make every preventing fertilizer, animal waste, or pesticide runoff into pondsCollecting and Submitting Fish Samples:many different sources of stress can contribute to �sh may be suffering from more than one disease simultaneously, water samples in the same container. Recent (fresh) 3 behavior at the water surface or pond edges. Dying �sh in a cooler of water or a large plastic bag with water or shipped by overnight carrier service. Always call the In Virginia, �sh samples can be submitted for disease State Veterinary Diagnostic Laboratory116 Reservoir StreetHarrisonburg, VA 22801Virginia-Maryland Regional College of Veterinary Virginia Tech, Blacksburg, Virginia 24061Emergency Actions:Drug and Chemical Treatments:effective therapeutic drug or chemical and applying it in the most appropriate legal manner. In using be particularly effective for certain bacterial diseases. that sick �sh may not eat. The dip method requires that sick �sh be captured and treated. The dip method for a short time period. The �nal method, whole and ineffective. Calculating the volume of the pond, the pond with healthy �sh. Treating sick �sh in and Drug Administration for use in food �sh and regulated by the Environmental Protection Agency to 4 Disclaimer Commercial products are named in this publication for informational purposes only. Virginia Cooperative Fish Kill Investigation Information and Questions:runoff?Was just one species of �sh killed?Were both large and small �sh killed?ReferencesRottman, R. W., R. Francis-Floyd, P.A. Reed, and R. Durborow. 1992. Submitting a sample for �sh kill investigation. Southern Regional Aquaculture Center Publication 472, Mississippi State Univ. MS. Durborow, R.M., and R. Francis-Floyd. 1996. Univ. MS. Rottman, R. W., R. Francis-Floyd, and R. Durborow. 1992. The role of stress in �sh disease. Southern Regional Aquaculture Center Publication 474, Mississippi State Univ. MS. Federal Joint Subcommittee on Aquaculture. 1994. Guide to Drug, Vaccine, and Pesticide Use in Aquaculture. Texas Agriculture Extension Service, College Station, TX. Table 1. Chemicals and drugs generally used in treating �sh diseases and parasites. Application dosage will vary Product/ChemicalRegulatory Agency Vinegar (acetic acid)EPAWater qualityEPATerramycin (oxytetracycline)Reviewed by Michelle Davis, research associate, Fisheries and Wildlife