Dedicated To Tribal Aquaculture Programs
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June 2009 ~ Volume 68 | |
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Topics of Interest:
La Crosse Fish Health Center
La Crosse Fish Health Center
The La Crosse Fish Health Center, in Onalaska, Wisconsin, was established in 1962 by the United States Fish and Wildlife Service Act of 1956. The laboratory at that time was located at the Genoa National Fish Hatchery in Genoa, Wisconsin. The laboratory relocated to the USGS Upper Midwest Environmental Science Center in 1980, moved to temporary quarters in 1993 and then moved to the USFWS Resource Center in Onalaska in January of 1995.
The Center serves an eight state area in the Big Rivers Region and Great Lakes basin and is part of the national system of nine fish health laboratories which assist national fish hatcheries in the diagnosis and control of infectious fish diseases.
Fish Health Center Goals
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Provide fish health services to six national and several tribal fish hatcheries to minimize the risk of disease agents impacting fish restoration
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Assist state and private fish hatcheries in diagnosing and controlling infectious disease agents
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Provide technical assistance regarding fish health and propagation
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Conduct wild fish health surveys to determine and monitor the distribution of fish pathogens in free ranging fish populations
The Center provides services to state, federal and tribal fish hatcheries and to the Great Lakes Fishery Commission.
Fish raised in hatcheries are particularly susceptible to a variety of diseases. For this reason, biologists trained in fish health management and a technical staff trained in diagnostic procedures are at fish health centers to assist fish culturists. The La Crosse laboratory is equipped to identify fish viruses, bacteria, parasites, and other environmental and nutritional diseases.
Disease Diagnostics
Most hatcheries are equipped to diagnose and treat common fish diseases. If disease problems exceed the capabilities of hatchery staff, the Center can provide additional assistance. When infectious diseases occur in reservoirs and ponds, or a hatchery experiences fish losses of an unexplained nature, the Center is alerted and fish samples are either brought to the laboratory or collected on site by a fish health specialist. The fish samples are then screened to determine the cause of mortality. When feasible, treatments or control measures are recommended.
Disease Inspection of Fish Facilities
A disease inspection consists of taking representative samples of fish populations at a facility and screening them for certifiable viral, bacterial, and parasitic fish pathogens. Most states require this documentation of fish health status before transporting fish within or out of the state, or before stocking into the Great Lakes.
The Center maintains a master list of disease status of all federal and state hatcheries within the region and of private hatcheries that are participants in the Great Lakes Fishery Commission cooperative. This requires biannual disease inspections of production and brood stock facilities. A high degree of technical accuracy is required in inspection work because results are used as the basis for many fish transfers within and outside of the Region. Wild fish populations whose progeny are intended for use in agency programs or on hatcheries are also included in the health inspection program.
Fish Quality Assessment
The La Crosse Fish Health Center annually conducts fish quality assessments on lake trout reared at National Fish Hatcheries in the Great Lakes/Big Rivers region. Specific external and internal characteristics are evaluated to determine the overall condition of the fish. The data provides an indication of the condition of fish at a particular facility and establishes values associated with normal health conditions at the facility.
Extension Services
The Center is also involved in the distribution of technical information regarding fish health, fish disease control, and fish propagation. Staff members are frequently called upon by all user groups to provide advice and direction in matters of fish health.
If your Tribal fish hatchery program should need the services of a fish health inspection, please consider contacting the Fish Health Center in your region (see information provided below).
Conserving this Nation’s fish and other aquatic resources cannot be successful without the partnership of Tribes; they manage or influence some of the most important aquatic habitats both on and off reservations. In addition, the Federal government and the Service have distinct and unique obligations toward Tribes based on trust responsibility, treaty provisions, and statutory mandates. The Fisheries Program plays an important role in providing help and support to Tribes as they exercise their sovereignty in the management of their fish and wildlife resources on more than 55 million acres of Federal Indian trust land and in treaty reserved areas.
Diseases Common to Fish Culture
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Bacteriology Bacteria are one-celled microscopic organisms which live and grow naturally in nearly all environments. In a balanced ecosystem, bacteria and fish can live in harmonious equilibrium. Aquaculture practices, however, often disrupt the normal balance between fish and environmental bacteria. Crowding, improper flow rates, poor water quality, handling and poor diet can all offset the natural balance between fish and the environmental bacteria, thus increasing the fish's susceptibility to pathogenic organisms. Bacterial diseases that we screen fish for include: |
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Virology Viruses are submicroscopic parasites that infect cells and cause damage or destruction to them. All known viruses are infective agents and are often specific to a particular host organism. Many viral infections will not produce symptoms. Viral diseases that we screen fish for include: |
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Parasitology A parasite is an animal which lives in or on another animal (the host). The parasite depends on its host for food and causes injury by inducing tissue and organ damage. This damage increases the fish's susceptibility to secondary bacterial infections. Parasites can also serve as carriers of viral and bacterial diseases. Parasites that we screen fish for include: |
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Fungal Diseases |
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Standard Hatchery Practices Diseases of Pacific Salmon
By: James Wood
SANITATION
The origin of most infectious diseases of young salmon can be traced to an infected diet or to infected fish in the water supply. A disease-free water supply to a hatchery is an ideal that continually eludes us. The main water supply to nearly all hatcheries comes from a stream that supports fish life. At present, there is little that can be done at the practical level to prevent disease-causing organisms from reaching young salmon being reared at the hatchery. Since young salmon must be exposed to certain levels of disease-causing organisms before a disease outbreak ensues, anything that can be done to limit the numbers of fish in the water supply may be of benefit. Sanitation, as applied to the management of the hatchery proper, varies somewhat from the problems of public health but the basic concepts are similar. If an infectious disease becomes epidemic in one pond at a hatchery, other ponds of salmon on the premises may be in danger.
Fish diseases are water borne and are readily transmitted from one pond to another by anything that goes into the water; e.g., picks, brushes, seines, and boots. All these items can be sanitized easily by dipping and rinsing in some inexpensive disinfectant. Quaternary ammonium compounds; such as Hyamine 1622, Hyamine 3500, Cyncal, Roccal, and Hyamine 10X; are presently recommended. During epidemics, a 5-gallon bucket filled with a strong solution of one of these disinfectants may be kept in a convenient location to rinse small implements prior to use. Preferably, separate tools should be used for yearlings than are used for fry and fingerlings. Yearlings often carry disease organisms; while not harmful to them, they are easily transmitted to, and are detrimental to, younger fish. If separation of tools is not possible, set up containers of disinfectant at strategic locations and disinfect equipment between critical ponds. In this regard, try to program the ponding of fry so that they are not adjacent to yearlings.
Dead and dying fish, covered with lesions, release swarms of disease organisms into the surrounding water and are frequently "picked" and cannibalized by their healthy kin. Sick and dead fish should always be removed with the utmost possible promptness.
Sunshine, in itself, is a fine sanitizer and few fish disease bacteria or parasites can last very long under the combined assault of drying and sunshine. Fish handling tools should always be dried in the sun; ponds, which have contained fish, should be allowed to dry before new stocks of fish are added. If time, sunshine, and dry weather are at a minimum, as they usually are, the pond walls and bottom should be thoroughly cleaned; then treated with a strong solution of a disinfectant. They should then be allowed to stand empty for a day or two before thoroughly flushing prior to restocking. Recommended, at present, is a 600 ppm solution of Hyamine 1622. This concentration is obtained by using one measuring cup of liquid Hyamine 1622 (50% active ingredient) in 50 gallons of water.
POND CLEANING AND OTHER UNPLEASANT TASKS
The topic of pond cleaning is subject to a great deal of individual interpretation. There are those that only scrub their ponds once a year, whether they need it or not, and get by fine. More power to them — as long as the fish never have to be treated or handled and the muck doesn't replace all of the water in the pond. There are others who are constantly cleaning their ponds and credit their good fortune to the resultant cleanliness. More power to them also — as long as there is time left to feed the fish properly and the fish aren't so spooked that they are afraid of anything coming near the pond, even the food.
Somewhere in between appear the bulk of the salmon culturists. The ponds are usually kept clean enough so that the fish may be treated or handled without a major cleaning being necessary. The fish are not being disrupted every day or two by the man with the brush and they are carefully fed so as not to waste food on the pond bottom. So far, the goal of a self-cleaning pond, under full production conditions, appears to be an illusion. The nearest thing to it are some of the large ponds where digestion of solid wastes takes place. Even these ponds when using an open stream water supply act as settling basins for water borne sediment. Cleaning of these large ponds is only feasible after the fish are released thus greatly reducing routine cleaning chores at the hatchery. Sediment and wastes at this time should be removed preferably as landfill; not flushed down the drain.
The adaptation of swimming pool cleaning heads for fish ponds works very well in ponds with concrete or asphalt bottoms. The cleaning head is best used with a floating type hose and a trash pump. Large amounts of sediment and fish wastes may be removed from the pond without roiling the water and with a minimal disturbance of fish.
All activities in the rearing pond should be conducted with only minor disturbance of the fish. The less you bother your fish, the less they will bother you. However, don't use this adage as an excuse for not carrying on routine chores around the hatchery; but, when it is necessary to handle your fish, use common sense and do it gently. If past history indicates a seasonal occurrence of a certain disease problem at your hatchery, try to schedule all pond manipulations well in advance or after this season.
Disinfection Techniques/ Options: Preventing Spread of Pathogens, Bacteria and Invasives, Boats, Motors, Trailers, Equipment
By: Corey Puzach and Dave Wedan
Fisheries Biologist, La Crosse Fish Health Center
Methods described below are only effective after proper preparation of infected equipment. After loading and securing boat and equipment on your trailer, the boat, motor, trailer, and other gear must have all aquatic vegetation, soil, and water drained and removed BEFORE TRANSPORT. Upon leaving a worksite possibly infected with pathogens or invasive species, a proper disinfection must be completed before re-use of boat in another waterway. Contact time is crucial for complete disinfection. Contact time reflects exposure of air, water, or disinfectant to a specific area, and not the total amount of time spent disinfecting. For example, if you are using 70 C water to disinfect your boat, you must apply 70 C water to each area for one minute or longer (see options and procedures below).
Methods |
Procedures |
Positives |
Negatives |
Heat + Air |
30C (86 F) 24 hours minimum |
Chemical free |
Time consuming |
(Drying in hot sun/air) |
(time at temp contact period crucial) |
Effective, but only if |
Weather/Temperature |
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(exposure to hot sun/ air while dry) |
properly done under |
criteria critical to |
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ideal conditions |
reliable results |
Heat + Water |
50C (122 F) contact time 10 minutes |
Chemical free |
Must maintain high water |
Spray &/or immerse |
(time and temp contact crucial) |
Same as above |
temp/contact; hotter than |
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(source of very hot water needed) |
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normal tap or carwash |
Heat + Water |
70C (158 F) contact time 1 minute |
Chemical free |
Must maintain very high |
Spray &/or immerse |
(time and temp contact crucial) |
Same as above |
water temp/contact; much |
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(source of super hot water needed) |
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hotter than tap/carwash |
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Risk of burns |
Chlorine + Water |
Min. 98 mg/liter water for 2 minutes |
Widely available |
Follow MSDS directions |
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(immerse in solution, apply directly, or |
Effective |
for health risks and |
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spray-on with pressure washer and rinse/neutralize thoroughly) |
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use personal protective gear ppg. Highly Corrosive |
Quarternary Ammonium+ Water * |
Follow product directions for proper mixture and minimum contact time. |
Effective, user- friendly |
Chemical based |
(family of products) |
(immerse in solution, apply directly, or |
Low health risks |
Follow MSDS directions |
“Extra” is a product option |
spray-on with pressure washer & rinse) |
Sewer compatible |
for health risks and use ppg. |
* Product name “EXTRA”-used by La Crosse Fish Health Center & Fishery Resource Office: prep & thoroughly wet surface with 3.2 oz extra/ 1 gal water (Fish Health recommendation) Solution can be applied with cloth, mop, sponge, coarse spray or soaking. Contact time-10 minutes. Rinse or allow to air dry. Company customer service contact is 800 424-1075 for this product, MSDS, or dealer information.
Gyrodactylus Study Completed
By: Becky Lasee, Project Leader, La Cross Fish Health Center
Staff from the La Crosse Fish Health Center, Iron River National Fish Hatchery and the Upper Midwest Environmental Sciences Center (USGS) recently completed a study determining the effectiveness of hydrogen peroxide in controlling Gyrodactylus outbreaks in brook trout. Gyrodactylids are small ectoparasites which can cause serious problems if they are found in high numbers on the skin and gills of fish. These parasites are unique because they are viviparous, or live bearing, meaning that a developing embryo can be observed inside the adult. Over the course of the study, brook trout were separated into treatment groups and mucus scrapes were observed for the presence of parasites. The parasites were counted and identified. Species identification involved measuring and observing the shape of different sclerotized parts of the parasite. The results of this study will be published in a fisheries-related journal.
Hydrogen Peroxide Study at Iron River NFH
Submitted by: Carey Edwards, Iron River NFH
Gyrodactylus spp. is a naturally occurring parasite found in Schacte Creek, which supplies the Iron River National Fish Hatchery (NFH) with 4,000 gallons of spring water per minute. Under normal circumstances, this parasite poses little to no problems for nearly 2 million fish produced or 6,000 adult fish reared and maintained at the hatchery. However, adult post-spawn coaster brook trout historically suffer from heavy Gyrodactylus spp. infestations. Treatment options have been limited to formalin which is approved by the Federal Drug Administration for use with fish.
Hydrogen peroxide, if proven effective, would be preferred because it readily breaks down in water to form oxygen and water and is less harmful to humans and the environment than formalin. A study was proposed by the Upper Midwest Environmental Science Center (UMESC) to test and confirm the efficacy of 35 percent hydrogen peroxide to reduce the infestation density of Gyrodacylus spp. on coaster brook trout. Prior to the beginning the study, Iron River staff set up fifteen equally sized compartments with 50 gallons per minute water flow in each, and a treatment area with two round tanks marked for 100 gallons. The 21-day study began on December 2, 2009 with three treatment days occurring every other day and samples taken on the seventh and 21st day. Iron River NFH and UMESC staff randomly assigned 20 female and 20 male coaster brook trout to each compartment. An additional 10 fish were collected for transfer to the La Crosse Fish Health Center for a thorough disease work-up. Length, weight and skin scrapes were taken from 60 random fish from the study group before placement into compartments. Skin scrapes were analyzed and parasites were counted.
Each raceway compartment was randomly assigned five treatment regimens: a control; a 15 minute salt bath followed by a 30 minute 100 parts per million (ppm) hydrogen peroxide bath; a 15 minute salt bath followed by a 15 minute 150 ppm hydrogen peroxide bath; a 30 minute 100 ppm hydrogen peroxide bath; and a 15 minute 150 ppm hydrogen peroxide bath. The study was intended to be blinded so that personnel enumerating parasites and verifying treatment concentrations would not know the assignment of treatment concentrations for each compartment. The treatment regimen was known only by staff carrying out the treatments. All chemicals were pre-measured the day before the study by UMESC staff.
Fish were transported on a cart in a container of water to the treatment area and then transported back to the original compartment when the treatment was complete. Dissolved oxygen, temperature and salinity were monitored and recorded during the treatments. A sample of the hydrogen peroxide bath was taken five minutes prior to the end of treatment and given to NFH personnel for titration to confirm the concentration of the bath.
Water quality was measured each day at the outlet of each raceway and each compartment was monitored for mortalities and moribund fish. Ten female and 10 male brook trout were randomly sampled from each compartment on the seventh day and given a fin clip. Length, weight and skin scrapes were taken from each fish. Skin scrapes were analyzed for Gyrodactylus spp. and counted. On the 21st day, the unclipped fish were analyzed and the fish were transported back to their original rearing space. Preliminary results look promising for the effectiveness of hydrogen peroxide for treatment of Gyrodactylus spp. on salmonid species. Initial analysis of post-treatment samples showed little to no parasites. The Iron River NFH staff enjoyed working with UMESC staff, and we eagerly await Food and Drug Administration approval of hydrogen peroxide for treatment of Gyrodactylus spp.
FYI:>> The MTAN previously discussed the use of hydrogen peroxide in the following issues: 8, 36 and 59
For more information on Gyrodactylus: http://www.gyrodb.net/biology.php, http://www.thefishsite.com/articles/104/parasite-focus-gyrodactylus
Links to National Fish Health Centers
US Fish & Wildlife Service, National Fish Health Center
Bozeman Fish Health Center, 920 Technology Blvd., Suite G, Bozeman, MT 59718
California-Nevada Fish Health Center, 24411 Coleman Fish Hatchery Road, Anderson, CA 96007
Idaho Fish Health Center, P.O. Box 272, Orofino, ID 83544
La Crosse Fish Health Center, 555 Lester Avenue, Onalaska, WI 54650
Lamar Fish Health Center, P.O. Box 155, Lamar, PA 16848-0155
Lower Columbia River Fish Health Center, 201 Oklahoma Road, Willard , WA 98605
Olympia Fish Health Center, 3859 Martin Way E, Suite 101, Olympia, WA 98506
Pinetop/Dexter National Fish Hatchery and Technology Center, P.O. Box 219, Dexter, NM 88230
Warm Springs Fish Health Center, 5308 Spring Street, Warm Springs, GA 31830
Related Links to National Fish Health Center Activities
- USFWS Aquatic Animal Health Policy
- USFWS National Fish Hatchery System Homepage
- National Aquatic Animal Health Plan
- Aquatic Animal Drug Approval Partnership (AADAP)
- USFWS-AAHP Quality Improvement Program
- USFWS-AAHP QA/QC Plan (PDF - 143kB)
- OIE - Aquatic Animals Commission
Other Links
- Approved Drugs for Use in Aquaculture (PDF - 610kB)
- Fish Disease Diagnosis and Treatment Index (be sure to review the Advanced Fish Disease Section)
- Disease Prevention on Fish Farms (PDF), R.W. Rottmann, R. Francis-Floyd, and R. Durborow
New Design for Fish Rearing Tanks
By Daniel Miller, Ph.D., Research Associate -Aquaculture
West Virginia University, ph: 304-293-4832 ext.4465
U-NEEK™ Tank
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Reduce Your Cost of Tank
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Ideal for:
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This tank design is lightweight, easily modified, tough but still flexible. A 2,000 gallon U-NEEK™ tank costs approximately 55% of a similar pre-cast concrete tank. In addition, it is easy to install, modify and transport. Solids removal is much faster than flat bottomed tanks. In a raceway application study, the time required for waste removal in the plastic tanks was less than half the time to clean compared to a flat bottom concrete tank of similar size. Call 304-376-1289 for technical information.The smooth plastic is easy to clean and less abrasive than concrete. If used indoors, “stabilizing feet” can be added to maintain tank stability. Outdoor use requires setting the tank partially into the ground. Solids tend to settle next to the manifold pipe at the bottom of the tank. When an external or internal valve (for freezing conditions) is opened, the solids enter (via hydrostatic pressure) the manifold and are removed from the system without any pumping or siphoning.
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Product and company names mentioned in this publication are for informational purposes only. It does not imply endorsement by the MTAN or the U.S. Government. |
