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Ashland NFWCO
 Midwest Region
 ***Dedicated To Tribal Aquaculture Programs***
          Fish Jumping
              **September 2007 ~ Volume 61****Coordinator:
Frank G. Stone 
(715-682-6185) Ext. 12
U.S. Fish and
                  Wildlife Service
Email: [email protected]** Topics
  of Interest: MTAN ArrowPortable Fish Rearing Facility
      MTAN ArrowFish Health Advisory ~ VHS
      MTAN ArrowStress and Fish Health
      MTAN ArrowTreatment of Fish Diseases
      MTAN ArrowCalculating Treatments for Ponds and Tanks
      MTAN ArrowPond Fertilization Basics
      MTAN ArrowAquatic Animal Drug Approval Partnership Program Update  Portable Rearing 
  Facility and Spawning Habitat Reclamation
Aid Remnant Lake SturgeonAaron Paquet, Environmental Scientist, Northern Environmental, 
    Lansing, MI.  1-517-702-0470 **+**
          
          **=**
 Lake 
  sturgeon (Acipenser fulvescens) are an ancient, long-lived, and 
  hardy fish that were once abundant throughout the Great Lakes.  Sadly, 
  as Europeans settled in the region and altered its landscape through 
  logging, commercial fishing, and development, the Great Lakes largest 
  fish declined precipitously in abundance.  Today, lake sturgeon remain 
  in only low numbers and their populations exist in only a small fraction 
  of the historic range. Over fishing and other human-induced pressures drove the sturgeon into 
  decline.  However, it is diminished reproduction resulting from these 
  low population numbers and a lack of available and/or accessible 
  spawning habitat that has perpetuated their suppression.  The Little 
    River Band of Ottawa Indians (the Tribe) recognizes the importance of 
  this very unique species and is leading efforts to protect and restore 
  it.  Their first objective was to help the genetically distinct, remnant 
  population of sturgeon that spawns in the lower Manistee River.  In a 
  given year, less than 90 members of the population are believed to 
  spawn, and only a small fraction of those are female. Recognizing the immediacy of this small, remnant populations 
  need, the Tribe initiated a concerted effort to bolster successful 
  reproduction.  In 2004 the worlds first portable streamside sturgeon fry rearing 
  facility, custom built on behalf of the Tribe by Northern Environmental 
    Technologies, Incorporated (Northern Environmental), was put into 
  operation along the lower Manistee River.  Rearing fry in a streamside 
  facility, as opposed to in offsite hatcheries, is expected to maintain 
  the natural imprinting of the young sturgeon to the Manistees unique 
  physiochemical characteristics. This is essential to preserving the 
  distinct genetic identity of the Manistee Rivers spawning population by 
  encouraging high fidelity to the sturgeon's stream of origin.  This 
  may also protect other small, remnant populations by minimizing the 
  straying of Manistee River sturgeon into other systems. Since inception, the portable facility and rearing process have 
    undergone numerous refinements, ultimately rendering the robust and 
    adaptable platform for streamside fish hatching and/or rearing thats 
    available today.  Following the success of the Manistee River rearing 
    facility, the Tribe and a coalition including the Great Lakes Fisheries 
    Trust Wisconsin Department of Natural Resources, U.S. Fish and Wildlife 
    Service, Michigan Department of Natural Resources, and Northern 
    Environmental collaborated to place four additional portable streamside 
    sturgeon rearing facilities around the Lake Michigan basin.  Installed 
    at locations on the Milwaukee and Manitowoc Rivers in Wisconsin and the 
    Cedar and Whitefish Rivers in Michigan, this initiative is intended to 
    restore or bolster sturgeon reproduction in tributaries around Lake 
    Michigan that historically hosted spawning. Increasing successful reproduction through streamside rearing is only a 
      starting point for sturgeon restoration.  The key to ensuring their 
      long-term recovery and sustainability in the Great Lakes will be 
      restoring and reclaiming suitable spawning and rearing habitats in 
      tributary rivers and streams.  Although sturgeon spawning habitat has 
      been created in some Great Lakes states, the method used (i.e., armoring 
      river banks with stone rip rap) can be detrimental to long-term stream 
      stability and the habitat of other organisms.  With that in mind, the 
      Tribe set out to find a better way. During 2005, the Tribe and Northern Environmental once again 
        collaborated.  This time, both the Manistee Rivers primary sturgeon 
        spawning site (an man made deposit of stone in a reach locally 
        known as Suicide Bend) and the documented conditions of other North 
        American sturgeon spawing habitats were evaluated.  The findings were 
        then contrasted to the conditions of a reach (locally referred to as Tunk 
        Hole) immediately adjacent to Suicide Bend.  Our goal was to determine 
        what factors contribute to, and limit, suitable spawning habitat at Tunk 
        Hole.  By combining strategies developed from the gathered information 
        with contemporary stream habitat restoration tactics, we developed an 
        ecologically, culturally, and aesthetically-sound manner for creating sturgeon 
        spawning habitat at Tunk Hole was discerned.  This effort has laid the 
        groundwork for reclaiming Tunk Hole. Portable Rearing Facility Custom Signage Adorns the Little River Band of 
            Ottawa Indians Portable Rearing Facility and Helps Promote Public 
            Recognition of the Tribes Commitment to Reviving and Protecting 
            Manistee River Lake Sturgeon.
            
            
            A Secure Stream-Side Location is ideal.  
          Not only for 
          Portable Rearing Facility Operation but also For Providing 
          Educational Tours.
          A Filtration and Degassing System to Manage Fine 
            Sediment Transport and Gas Supersaturation is Custom Designed for 
            Each Portable Rearing Facility. The Custom Design is Matched to 
            the Water Quality of a Given Site. This Helps Reduce Flow-Through 
            System Maintenance While Maintaining Ambient Water Characteristics 
            that are Important to Imprinting Young Fish.Portable Rearing Facilities Creatively Integrate 
            Existing Technologies to Preserve Unique Fish Populations of 
            Cultural, Ecological, and Recreational Value.
            
            
            
            Portable Rearing Facilities Include a Wet Lab, 
          Water Quality Monitoring Equipment, and Other Custom Features that 
          Facilitate Successful Fish Hatching and/or Rearing.
          Portable Rearing Facilities are Available in a 
            Variety of Sizes and Configurations to Accommodate Different Life 
            Stages and Multiple Genetic Groupings in a Safe and Convenient 
            Work Environment.Collaborating with Northern Environmental to 
            Develop Portable Rearing Facility Technology and Take Steps Toward 
            Reclaiming Sturgeon Spawning Habitat are Extensions of The Little 
            River Band of Ottawa Indians Ongoing Efforts to Revive the 
            Manistee Rivers Lake Sturgeon Population.
            
            
            Portable Rearing Facility Intakes Are Located To 
          Minimize Maintenance and Help Ensure a Constant Supply of Fresh 
          River Water is Delivered to Fish Being Reared.
          Juvenile Manistee River Lake Sturgeon Successfully 
            Reared in the Little River Band of Ottawa Indians Portable 
            Rearing Facility and Nearing ReRelease into the River by Tribal 
            Members.
  Fish Health Advisory ~ VHS
By: Wisconsin Dept. of Agriculture Click here to view this pdf document (484KB)   Stress and Fish Health Reprinted from: Introduction to Fish Health ManagementLa Crosse Fish Health Center 
Edited By:  Becky Lasee, USFWS Stress is a major contributing factor in disease outbreaks. Seyle 
  (1950) defined stress as "the sum of all the physiological responses by 
  which an animal tries to maintain or reestablish a normal metabolism in 
  the face of a physical or chemical force." In other words, stress occurs when the fish is faced with 
            environmental or other factors that extend the stabilizing (or 
            homeostatic) processes beyond the fish's normal limit.  A stress factor or stressor is an environmental change that is severe 
      enough to require a physiological response on the part of the fish. If 
      the response of the fish is sufficient to reestablish a satisfactory 
      relationship with the changed environment, then adaptation to the 
      stressor will occur.The physiological changes that occur following a stressor have been 
      termed the general adaptation syndrome (GAS) or stress response. GAS has 
      been described as consisting of: (1) an alarm reaction; (2) a stage of 
      resistance during which adaptation occurs; and (3) a stage of exhaustion 
      if adaptation does not occur because the stress was too severe or long 
      lasting. There are many environmental stressors associated with intensive 
      culture of fish. These include poor water quality (i.e. high ammonia, 
      nitrate, or pH, low dissolved oxygen and high levels of organics), rapid 
      environmental changes (i.e. fluctuating water temperatures) and poor 
      nutrition. Additional management practices, such as handling, seining, sorting, 
        grading, vaccinating, therapeutic treatments, fright, anesthesia, 
        crowding and transport also contribute to stress in fish. Stress induced 
        by environmental and management practices can result in reduced growth 
        (due to poor food conversion or weight loss), impaired spawning, altered 
        behavior, increased susceptibility to disease and even death. Examples of the effects of stress on disease resistance include 
          development of columnaris disease following handling of fish in warm 
          weather and outbreaks of fungus in the winter. Outbreaks of most 
          parasites and other types of bacteria can also occur following stress. Many of the stressors that occur in intensive culture can be 
            controlled through changes in management practices. The following 
        recommendations will assist in decreasing hatchery related stressors: Reduce handling of fish. Use proper handling and hauling procedures 
          when moving fish.If there is a seasonally to disease outbreaks, avoid handling fish two 
          to three weeks prior to and during the expected time of usual outbreaks.Avoid handling and crowding fish during hot weather.Avoid temperature shocks.Stresses can be additive; allow recuperation between stressful 
          situations.Avoid high loading densities.Provide optimal environmental conditions for the species being raised. 
          Maintain water quality within the suggested guidelines. Pay special 
          attention to maintaining optimal oxygen levels and minimal ammonia 
          levels. Test water quality parameters frequently and keep accurate 
          records.Provide food that meets the nutritional needs of the fish under the 
          cultural conditions being used.Maintain cleanliness of rearing facilities. This includes segregated 
          fish handling equipment or strict practices of disinfection of nets and 
          other equipment between lots or rearing units. Fish showing signs of 
        distress and dead fish should be removed.
      Where appropriate, use strains of fish species which show resistance 
          to the specific endemic disease. The fish culturist who has frequent contact with the fish should be 
      the first line of defense against a disease outbreak. The fish feeder 
      sees the fish regularly and should be alert to subtle changes which may 
      indicate severe stress in fish. Fish in good health actively feed and 
      quickly flee from disturbances. Fish in poor health gather near the 
      incoming water supply, do not feed well, are sluggish, swim high in the 
      water column, pipe air at the surface of the water and may flash on the 
      bottom of the holding unit. Changes in normal external and internal 
      appearance should also be observed (such as sores, lesions, and excess 
      mucus or color changes).  Treatment of Fish  Diseases
      Reprinted from: Introduction to Fish Health Management La Crosse Fish Health Center
        Edited By:  Becky Lasee, USFWS  Prophylaxis and  chemotherapy are two methods used to  treat diseases of fish. Prophylactic treatments are preventative and protect against the occurrence of an epizootic. Such treatments are used primarily for ectoparasites 
          and stress related bacterial diseases.  Chemotherapeutic treatments are initiated after clinical signs of the disease appear in a population of  fish. **17.5RULES OF CHEMICAL TREATMENT** 1. Fish should be examined to diagnose the disease or  problem to be treated. Seek professional assistance if in doubt of the cause.
      
      A "shotgun" treatment is poor policy and can lead
to drug resistant microorganisms.
      2. Determine general condition of fish. Fish may not be able  to with­stand standard treatments. In this case, it is advisable to give serial  treatments with progressively higher concentrations of the chemical.
      3. Clean holding unit before chemical treatment. Many  chemicals are in­activated by organic materials. A holding unit which is not  clean often provides a sanctuary for the organ­ism under attack.
      4. Remove fish from feeding schedule 24-48 hours prior to  treatment. Oxy­gen consumption is reduced when fish are taken off feed and fish  are more apt to withstand the treatment. 5. All leaks in the holding unit  should be repaired prior to treatment. This rule is important in order to  maintain a constant chemical concentration.
      6. Auxiliary aeration devices should be on hand and  operative. This rule applies more to bath treatments where oxygen depletion is  more likely.
      7. Determine proper dosage, amount or concentration of  chemical to be used. Always double check your chemical calculations. Determine  the correct method and route of application or administration. Accurately  determine withdrawal time of chemical.
      8. Compare economic value of fish with cost of treatment. If  cost of desired treatment is greater than the value of the fish, it may be  worth changing your choice of chemicals or even abandoning the treatment.
      9. Always check the route of chemical discharge at the  facility. It is possible that the chemical in use may cause environmental  damage after it leaves the unit being treated.
      10. Before beginning treatment, check the condition of  chemical being used. Some chemicals are altered when improperly stored. This  alteration could yield an ineffective or a toxic chemical.
      11. Check concentration of the stock chemical. Many  treatment recommendations are based on active ingredients.
      12. Dilute chemical before applying to the holding unit.
      13. Ensure proper mixing and distribution of the chemical in  the water column of the holding unit.
      14. NEVER leave the holding unit while treatment is in  progress.
      15. Observe fish closely during treatment. If distress is  observed, the treatment should be terminated, or if low dissolved oxygen is the  problem, additional aeration should be provided.
      16. Periodically examine fish to determine efficacy of  treatment.17. Do not stress (by handling, crowding, etc.) treated fish for  24-48 hours after treatment.
      17.5Make every effort to determine the predisposing factor or  factors for the condition being treated and correct for them if possible. If  the predisposing factor is not removed, it is likely that the condition will  reap­pear. TREATMENT METHODS
      Prolonged Bath Treatment.    For this type of treatment, the inflowing water is cut off, the volume  of water is determined and the correct dose of chemical is added to the unit.  After the designated length of contact time, the chemical is flushed out of the  unit rapidly (no longer than 10 minutes) with fresh water. An advantage of the  bath procedure is that a more precise treatment can be given to the fish. 
      The following precautions must be observed  with bath treatments in order to prevent serious losses: ♦     Aerators should be available to ensure  adequate oxygen if levels are depleted  during treatment. 
♦     The fish should  be observed throughout the treatment regardless of treatment time. Fresh water should be  added at the first signs of distress. 
♦     The chemical must  be uniformly distributed in the unit to ensure equal exposure of all fish to the chemical. No one procedure  is used for the distribution of treatment  chemicals within a unit. Rather, the method  of distribution depends upon several factors including the type of chemical used, type and size  of unit receiving the chemical, equipment,  labor available and common sense. ****Indefinite Bath Treatment** In­definite baths are usually used to treat  ponds. The chemical is applied at low  concentrations for extended periods of time. The chemical is al­lowed to gradually dissipate or detoxify naturally. This is generally considered a safe method of treatment but there are a few drawbacks. The most significant drawback is that treatments can be expensive because large quantities of chemicals are required. Another drawback relates to the  possible adverse effects on the pond  environment. Some chemicals are  algacidal or herbicidal and may kill enough plants to ultimately cause an oxygen deficit in the pond being treated.** ****Constant Flow Treatment**
      Constant  flow treatments are used in situations where it is impossible or impractical to shut off the water supply long enough to use one of the bath  treatments. The volume of water flowing  into the unit must be determined and  a stock solution of the chemical is metered into the in­flowing water to maintain a constant concentration. Upon completion of the  treatment period, the inflow of the chemical is stopped and the unit is flushed  by the continuous flow of fresh water.  Constant flow treatments require  large quantities of chemical which  can become quite costly. Furthermore, irregularly shaped raceways  cannot be treated in this manner.** ****Feeding and Injection**
      The  treatment of certain systemic bacterial diseases  requires that the drug be introduced into the fish's body; usually through the  feed or by subcutaneous injection. Treatment  dosages are based on body weight of the  fish. Standard treatments are given  in grams of active drug per 100 pounds of fish per day or in milligrams  of active drug per pound or kilogram of body  weight. Medicated feed is purchased  commercially. Once feeding of the  formulated medication has begun, it should be continued for the  prescribed treatment period.  Large and valuable fish, particularly when numbers are small, can be treated effectively by injection of the antibiotic directly into the body cavity  (intraperitoneal or IP) or into the muscle  (intramuscular or IM). Most  antibiotics work more rapidly when injected IP. For both types of injections, particularly IP, caution must be exercised not to damage internal  organs. 
      The most convenient location for IP injections  is at the base of one of the pelvic fins. The pelvic fin is partly lifted, the  needle placed at the fin base and gently inserted until its tip penetrates the  body wall. The needle and syringe should be held on a line parallel to the long  axis of the body and at about a 45 degree angle downward to avoid internal  organs. Penetration of the body wall is indicated by a sudden decrease of pressure  against the needle. As soon as the tip of the needle is in the body cavity, the  required amount of medication should be injected rapidly and the needle  withdrawn.  For IM injections, the best location usually  is in the area immediately anterior to the dorsal fin. The needle and the  syringe should be held on a line parallel with the long axis of the body and at  a 45 degree angle down­ward. The needle is  inserted to a depth of about 1/4 to *1/2*inch and the medication slowly injected directly  into the muscle tissue of the back. The injection must be done slowly, so that  the back pressure will not force the  medication out of the muscle through the channel created by the needle.** ****ACCEPTABLE USE OF CHEMOTHERAPEUTICS**
      The basic principal of chemotherapy is one of  selective toxicity. The drug must destroy  or eliminate the pathogen by either  bactericidal or bacteriostatic action, without having side effects on the host.  
      Numerous drugs and  chemicals have been used successfully  for the control of fish diseases.  However, many have not yet been registered by the U.S. Food and Drug Administration (FDA) for use  in fish aquaculture. Uses of therapeutics in aquaculture and their registration  status is listed in Table 10.1 /10.2. It  is up to the user to deter­mine whether a particular product is approved for an intended use in aquaculture  because the status of drugs and  chemicals is always subject to change due to research findings or regulatory agency rulings.Chemicals purchased for  hatchery use should be of United States Pharmaceutical (USP) grade, if possible. The  chemical formula should be on the label. Treatment compounds must be stored as directed on the label.  Lids or caps should always be tight.  Chemicals that develop an abnormal  color, texture, etc. or are held after the expiration date should be disposed of properly. Hazardous chemicals should be handled only with proper safety precautions.** ****Chemotherapeutics Added to the Feed** 
      Two drugs have been cleared by the FDA and are  currently available for use in treating systemic bacterial infections in  hatchery fish. These are Terramycin and  Romet 30. There are other drugs which have not yet been cleared for use but are identified here in  the event that they are registered in the future.** ****Terramycin (Qxytetracycline). APPROVED  FOR**USE **BY FDA**
      Terramycin is approved for control of  bacterial hemorrhagic septicemia and pseudomonas disease in catfish and  approved for control of ulcer disease, furunculosis, bacterial hemorrhagic septicemia  and pseudomonas disease in salmonids. 
      The drug is usually available in the form of TM-50 or TM-50D, the latter being a formulation containing a water dispersible carrier. TM-50D can be  used in starter diets or with pellets that require fine particles for processing. Terramycin, TM-50 and TM-50D  are trade names of Pfizer, Inc. for their  oxytetracycline products. TM-50 and TM-50D contain 50 grams of oxytetracycline hydrochloride  per pound of product. In other words, each 9  grams of TM-50 or TM-50D contains 1  gram of Terramycin. Terramycin has been a useful drug in treating  systemic bacterial infect­ions which have developed a resistance to sulfa drugs. However, Terramycin resistant strains of bacteria have also been encountered.** Dosage rate: Terramycin fed at the rate of 2.5-3.75 grams per 100 pounds of  fish per day for 10 days is usually  effective. Terramycin often stimulates the appetite of trout, but salmon  may find it distasteful. Terramycin should not be fed on a prophylactic basis  because resistant strains of bacteria may  develop. ****Romet_30. APPROVED FOR USE BY  FDA**
      Romet 30 is only available as a preformulated medicated  feed from commercial feed manufacturers. Romet 30 is approved for control of *Aeromonas  salmonicida*infections of trout and salmon, and *Edwardsiella  ictaluri*infections in channel catfish. The active drug is a combination of  two medications (Table 10.1 / 10.2 ) which compliment  each other's antibacterial action. In  addition, the chemical nature of these compounds reduces the  risk of bacterial resistance.** Dosage rate: Medicated feed is administered  for 5 consecutive days to provide  approximately 23 mg of active ingredients per pound (50 mg/ kg) of live  body weight of fish per day. Salmonids must be withdrawn from treatment at  least 42 days prior to stocking or slaughter; catfish require a 3 day  withdrawal period. ****Sulfamerazine.******APPROVED  FOR USE BY FDA BUT NOT PRE­SENTLY AVAILABLE BY SPONSORSulfamerazine is a sulfonamide that is  effective for treating infections caused by both Gram negative and  Gram positive bacteria. It is approved for control of furunculosis in rainbow,  brook and brown trout. The action of the drug within the fish is basically  bacteriostatic (it is the defensive mechanisms of the fish that ultimately kill  the bacteria).** **Sulfonamide toxicity may occur when high  dosages (10 grams per 100 pounds of fish per day or more) are fed to sensitive  fish. If high dosages are required, a combination of two sulfa drugs totaling  the desired rate should be fed. Toxicity usually results from the formation of  complex sulfa crystals in the renal tubules. Signs of drug toxicity include  abnormal bloating of the stomach (dropsy) and a chronic susceptibility of the  gills to fungus (in salmon). Exophthalmia, swollen kidneys and death occur in  acute cases.** Dosage rate: Sulfamerazine incorporated in  processed diets is fed at the rate of 10 grams per 100 pounds of fish per day  for 10 days (a 21 day withdrawal is required). This therapy should produce a  blood level of the drug of 9 to 12 mg per 100 ml of blood. ****Furazolidone. NOT  APPROVED FOR USE BY FDA**
      Furazolidone (Furox 50) is one of a large  number of related drugs in the nitrofuran group. The name Furox 50 is the trade name  of a product developed by the Norwich Pharmacal Company for a formulation containing 11% Furazolidone. This drug has provided good results in the treatment  of furunculosis and enteric redmouth in trout and against other Gram negative  rods in other fish species (especially in cases where there is drug resistance  against the sulfonamides and Terramycin).** Dosage rate: Furazolidone has been effective  when mixed in the diet at the rate of 2.5 grams of pure drug per 100 pounds of  fish for 3 days followed by a 20-day course of a 1.0 gram level per 100 pounds of fish. ****THERAPEUTICS  ADDED TO THE WATER** **Tricaine  methanesulfonate. APPROVED FOR USE BY FDA**
      Also known as FinquelTM  (or MS-222). It is used as an anesthetic at 15 to 330 ppm (mg/L)  for ictalurids, salmonids, esocids and  percids. For other aquatic organisms it is used at 1:1,000 to 1:20,000.  A 21 day withdrawal time is required.** ****Acriflavin. NOT  APPROVED FOR**USE **BY FDA**
      Acriflavin has been used in  the transport of warmwater fish to combat  delayed mortalities caused by  aeromonad and pseudomonad infections. Water in the transportation tank  must be maintained at 4.0 ppm Acriflavin for the duration of the trip.** ****Chloramine T. NOT  APPROVED FOR USE BY FDA**
      Chloramine T can be used in the treatment of various bacterial, fungal, protozoan and monogenetic trematode infect­ions.  It has been used as a bath treatment at 7-15 ppm for 1 hour. Efforts are currently  in progress to register this drug.** ****Copper Sulfate. NOT  APPROVED FOR**USE **BY FDA**
      At 0.5  ppm, copper sulfate (CuSO4) has  been used to control external parasites.** ****Di-n-Butyl Tin Oxide. NOT AP­PROVED FOR**USE **BY  FDA**
      This chemical is used to treat a variety of internal helminths. The  dosage rate is 250 mg/kg (114 mg/lb) mixed into the food for 3 days. This is  toxic to fry but not to adult largemouth bass.** ****Diquat. NOT  APPROVED FOR**USE **BY FDA**
      Diquat  has been registered only as an aquatic herbicide for use in ponds and  ditches. Diquat has been sold as a liquid containing 35.3% active ingredients. Fish culturists using Diquat to  control filamentous algae also found the  chemical to remedy bacterial gill disease, especially in earthen ponds. The chemical is expensive and muddy  water or heavy accumulations of fish wastes  may reduce its effectiveness. It appears to  have low toxicity to fingerling  salmon. Diquat has been used to treat salmonids at 2.0  ppm of active Diquatcation (1:500,000) (8.4  ppm from the bottle) for 1 hour. Applicators should use rubber gloves  and respirators to avoid contact with the  chemical. Because Diquat is a potent  herbicide, fish culturists should  avoid using Diquat whenever the treated water might  later be used for irrigating crops.** ****Formalin. APPROVED FOR USE BY FDA**
      Formalin (Paracide-FTM Formalin-FTM,  Parasite-STM) is probably  the most widely used therapeutic agent in fish culture. It is the common name for a solution containing 37 grams of formaldehyde in 100  grams of water. Methyl alcohol or calcium  salts may be added to prevent  chemical changes in formalin. Formalin is corrosive and may turn rusty  if stored in drums with scratched linings. Neither the rust nor the stabilizing chemicals added to formalin  have an effect on formalin for  treatment purposes. Old formalin or  formalin exposed to cold temperatures may form a white precipitate of paraformaldehyde.** **Formalin is effective against the majority of external parasites, with the possible exception of *Saprolegnia*fungal infections.  Formalin should be used at 167 to 250 ppm  for one hour in troughs, tanks, raceways and rectangular  concrete ponds. Water temperature is extremely  important (refer to Table 10.1 / 10.2 ).  Salmonids are somewhat  sensitive to higher concentrations of formalin  above 7-10°C. As a rule of thumb, use  167 ppm formalin for 1 hour if temperatures exceed 10°C. Repeat the treatment two or three times on succeeding days if  the parasites have not been removed. In  earthen ponds, which cannot be  flushed following treatment, use an indefinite treatment of 25 ppm formalin. If rearing ponds are heavily loaded with either fish or phytoplankton,  try a treatment of 15 ppm of formalin and  repeat if necessary at 5-10 day  intervals.** **Fish treated with formalin may suffer delayed mortality  5-6 hours post-treatment. This occurs frequently with rainbow trout yearlings,  especially if they have had no prior formalin treatments. Experience has shown  that if rainbow trout were treated with formalin when they were young, they  become resistant to formalin with age. The cause of formalin sensitivity is not  known.** **Formalin at 1667 ppm is effective against fungus which  attacks incubating eggs. Use 15 minute treatments, repeated as often as is  necessary to prevent fungal growth. 
      Formalin is highly toxic (and per­haps carcinogenic) to  humans! The strong odor and the eye irritation usually warn of its presence.  Long term exposure to low level formalin fumes is hazardous to human health.** ****Nitrofurazone (FuracinTM). NOT  APPROVED FOR USE BY FDA**
      Furacin is a nitrofuran antibiotic that acts  against bacterial organisms. It comes as a water mix and has been widely used  in the sorting and transfer of bait  minnows. Furacin dosage is 75 mg/kg (3.4 g/100 lb) of fish per day for  14 days. Repeated use has not been reported to harm fish.** ****Hyamine 3500. Hyamine 1622 and Boccal.** **NOT APPROVED FOR**USE **BY FDA**These are quaternary  ammonium chloride compounds that were  originally developed for disinfection in the dairy, food and restaurant  industries. They are potent antimicrobial agents and their value as therapeutic  agents have been recognized by the aquaculture society. Work is in progress for registering these compounds.** ****Masoten (Dylox). NOT  APPROV­ED FOR**USE **BY FDA**
      Masoten (80%  active ingredient) at 0.25-0.50 ppm as  an indefinite treatment is used to treat  monogenetic trematodes and copepod parasites.  Masoten should be applied in early morning and at water temperatures above 29°C. Protective clothing should be worn as this chemical can be absorb­ed through the skin.** ****Potassium permanganate. NOT APPROVED  FOR USE BY FDA**
      Potassium permanganate (KMnO4) is a strong oxidizing agent that has been  used to treat *Gyrodactylus*infestations  and other external para­sites. Use potassium permanganate at 2-4 ppm for 1 hour on 3 successive  days. This chemical also has some value in treating bacterial gill disease (at  3.0 ppm it alleviates gill tissue  proliferation).** ****Sodium chloride (Salt).** **LOW REGULATORY PRIORITY  DRUG BY FDA**
      It is 
      unlikely the FDA will object to using salt and  other low regulatory drugs as long as the following conditions are met: (1)  they are used as direct­ed; (2) they are used at prescribed concentrations; (3)  they are used according to good management practices; (4) the drug is an  appropriate grade for use in food fish; and (5) there is no likelihood of an  adverse effect on the environment.  
      Salt is administered at a 0.5 to 1.0% solution  for an indefinite period to reduce stress or a 3% solution for 10-30 minutes as  a parasiticide. Salt is useful for ridding fish of excess mucus, a common host  response to external parasites. Not only is salt one of the oldest and most  commonly used hatchery chemicals, it is also one  of the most overlooked.** ****Calcium chloride. LOW  REGULATORY PRIORITY DRUG BY FDA**
      Calcium chloride can be used, up to 150 ppm,  to increase water hardness for reducing stress when holding and transporting  fish. It is also used to increase water  calcium concentrations to ensure proper egg hardening.** ****Acetic acid. LOW  REGULATORY PRIORITY DRUG BY FDA**
      Use as 
      a 1,000 to 2,000 ppm  (mg/L) dip treatment for 1 to 10 minutes to remove  external parasites.** ****Hydrogen peroxide (H2O2).  LOW REGULATORY PRIORITY DRUG BY  FDA**
      Use at 250-500 ppm (mg/L) (100% active ingredient) for 15  minutes as an effective fungicide for incubating eggs and 250-500 ppm (30-60  minutes) for treating fish with external parasites. Other drugs considered low regulatory  priority include calcium oxide, carbon dioxide gas (as an anesthetic), garlic,  onion, ice, magnesium sulfate, papain, potassium chloride, sodium bicarbonate  (as an anesthetic), sodium sulfite and urea in combination with tannic acid.** ****Egg Water Hardening and  Disinfection** 
      The disinfection of fish  eggs began in trout culture because of concern about the spread of furunculosis. There is  little evidence that furunculosis can be  spread via eggs; how­ever, vertical transmission has been demonstrated for IPN virus, IHN virus  and BKD. Egg disinfection is effective in con­trolling  the spread of IHN virus with eggs, but is not useful for controlling vertical transmission of IPN virus and  BKD, which are carried inside the egg. Nevertheless, fish culturists routinely  disinfect trout and salmon eggs during or after water hardening (prior to  shipment or upon arrival).** ****Erythromycin phosphate. NOT  APPROVED FOR USE BY FDA**
      Erythromycin phosphate at 2.0 ppm for 1 hour  has been used during the water hardening of salmon eggs to prevent BKD egg  transmission. Although mixed results were obtained with regard to eliminating  BKD from eggs, treatments did result in improved rates of eye-up and fry  survival. It was suggested that erythromycin treatments removed bacterial  contaminants such as those that cause coldwater disease.** ****Providone Iodine  Compounds (BetadineTM). Low Regulatory Priority Drug by FDA**
      Use at rates of 50 mg/L for 30 minutes (at pH 6-7) during water hardening and at 100 mg/L  solution for 10 minutes (at pH 6-7)  after water hardening.  
      If alkalinity of water  used for disinfection of eggs is below 100 mg/L total alkalinity, the disinfection solution should be buffered by adding sodium  bicarbonate (NaHCO3) at a rate of 0.01  percent to prevent low pH drift. Listed below are quantities of 1 percent iodine or sodium bicarbonate needed to obtain the solutions required by these guidelines.** **To   get    100   mg/L   active    iodine solution:** 
           Add 37.8 ml organic iodine solution/ 3.78 L  water (=1 gallon). 
          Add 283.20 ml organic iodine solution/28.32 L water (=1 ft3). 
        Add 4.54 ml organic iodine solution/ 454 g  water (=1 lb).
     **To   get    50   mg/L   active    iodine solution;**
           Add 18.90 ml organic  iodine solution/ 3.78 L water. 
          Add 141.60 ml organic  iodine solution/28.32 L water. 
        Add 2.27 ml organic iodine solution/ 454 g water.
      To get 0.01% sodium  bicarbonate:
            Add 0.378 g NaHCO3 /3.78 L water. 
            Add 2.83 g NaHCO3 /28.32 L water. 
        Add 0.045 g NaHCO3 /454 g water.  ****Calculating  Treatments for Ponds and Tanks** 
      Michael P. Masser and John W. Jensen
      Southern Regional   Aquaculture Center,  August 1991** **Every fish farmer has to  occasionally use chemical treatments to remove fish, alter water quality, cure disease  and control aquatic vegetation.  The fish  farmer must follow treatment directions carefully, know the proper amount or  concentration of chemical to use and know the pond area and/or volume.  For information on calculating area and  volume request SRAC No. 103 *- Calculating Area and Volume of Ponds and  Tanks.*Regulation and/or approval of chemicals  for aquatic use is confusing to fish farmers and fisheries professionals,  alike. Aquatic chemicals are regulated federally by the Environmental  Protection Agency (EPA) and the Food and Drug Administration (FDA). An  oversimplified statement of their missions would be that the EPA regulates chemicals  applied to water while FDA regulates chemicals applied to fish.  The fact that approved chemicals can be used  only for purposes stated on the label (including the specific target species)  is commonly misunderstood. Chemicals approved for water treatment cannot be  used for therapeutic purposes nor can a therapeutant approved for one species  be used on another.  The above is true even of chemicals  given GRAS (Generally Recognized As Safe) status. The FDA and/or EPA can  approve treatments using unregistered chemicals on a case by case basis. For  information on special approval contact the appropriate federal agency.  Several chemicals commonly used in fish  culture have never been properly registered. Many chemicals will soon be  reviewed and either approved or barred for specific uses. Check with your county Extension  office or fisheries specialist for recent developments on approved fisheries chemicals.** If aquaculture products are to be perceived  as wholesome and safe by the consumer, all producers and processors must guard  against the misuse of or contamination from unapproved chemicals.
 ****Precautions when making chemical  treatments**
      Chemicals can react quite  differently in water depending on its quality and on the target species.  For example, less copper sulfate should be  used in water of low alkalinity than in water of high alkalinity.  To be effective, more potassium permanganate is  needed as organic content increases.  Furthermore,  fish already weakened by stress or disease may succumb to even a normal  chemical dose.  **To avoid overdosing fish with a  chemical, a simple bioassay should be conducted**In a bioassay a small sample of fish  from the pond is treated, in the ponds water, with the proposed chemical  dosage to determine its safety and effectiveness.  Check oxygen concentrations carefully and be  prepared to aerate after chemical treatments, particularly after using  potassium permanganate, copper sulfate or formalin.  Use accurate, sensitive scales to weigh  chemicals when treating small volumes of water such as the amounts in hauling  or holding tanks, hatching troughs and cages.   If a suitable scale is not available, commonly available measuring spoons  and cups can be used.  Cups and spoons  are not the best way to measure chemicals, but are better than using inaccurate  scales or eyeballing the dosage. Accurate spoon and cup measures must be  used. Purchase only utensils labeled U.S. Standard Measure or ask a  pharmacist to check the volumes of your measuring devices with his accurate  measures.** Inaccurate chemical measurements can harm or kill fish  or fail to do the intended job. ****Conducting a simple bioassay**
      A simple on-site test can be done to  determine if an approved chemical could be toxic under specific pond  conditions. The test should be run using both fish and water from the pond to  be treated.  The test exposes a few fish  to the concentration of the proposed chemical treatment while other fish are  confined in the same type of environment as the fish in the treatment, but  without any chemical exposure (called a control).   Tests can be done in plastic  buckets, aquaria, or in plastic bags suspended in the pond. Dissolved oxygen  and other water quality conditions must be maintained as closely as is  practical to that of the pond. Aeration and water replacement (before the test  is started) may be required to maintain water quality.  Do not overcrowd the fish in the treatment  containers. A safe level of crowding would be to keep fish weight at or below  one thousandth of the weight of the water used in the test (i.e., 1 pound of fish  to 1,000 pounds of water).  Tests should  be run in duplicate or triplicate so that a chance error or mistake will not be  misinterpreted.  It is best to observe  the fish in the test containers for at least one day before treatment to reduce  the chance of deaths caused by handling. The test should be run for 24 to 96  hours. If the chemical is known to detoxify in 24 hours or less, the test can  be concluded after 24 hours. If the toxicity of the chemical is unknown, its  best to run the test for 96 hours. Follow the basic procedure described below  to conduct a bioassay.** ♦ Place fish (minimum of 10) in  each container. Use at least two containers for the treatment and two for  controls.♦ Observe for at least 24 hours.♦ Add chemical at desired  concentration to the test containers; add nothing to the control containers.
      ♦ Observe for 24 to 96 hours.  Record mortalities. **If fish are still alive after the  test, it should then be safe to treat the pond. If some fish die, you must decide  if some mortalities are acceptable. Chemical treatments may kill fish that are  already severely stressed. Pond Fertilization Basics** Fertilization regimes can be used to improve the food base  for cultured fish.
          Fertilizers are categorized as inorganic or organic.
          Inorganic fertilizers are granular or liquid, and are used  to increase phytoplankton abundance (algae), or the "bloom".   They are applied by formula and goal  ratios.
          Organic fertilizers can be hay, meals, or manure. Amount of  nutrients supplied  varies due to the composition of the fertilizer.
      If using an inorganic method, it is suggested that you  monitor the water quality in your pond weekly, and you will need to know the amounts of:
        Nitrate (NO3)
              Ammonia (NH3)
          Phosphorous (phosphate, PO4) These numbers are used to calculate the amounts of fertilizer that needs to be added.  However, the ammonia value may not be needed in the overall calculations,  since it can be a very low number. Fertilization can be done to maintain  a goal ratio, either Culver's 20:1 (TN:TP) or Mischke's 7:1 (NO3:TP).
          You will also have to monitor pH and dissolved oxygen (DO)  on a daily basis.
      It is highly recommended that you have fertilizers analyzed  to determine exact concentrations of Nitrogen and Phosphorus and to make sure there is no  contamination (extra amounts of fertilizer).**** ****Basic Pond  Fertilization Equations Based on Culver's Method of  20:1 (TN:TP)**** Recall, 20:1 is 600ug/L N (microgram per liter) to 30 ug/L P (0.6mg/L N:  0.03mg/L P). A microgram is 1,000 milligrams. ****1. To determine  phosphorus amounts:**** V = (30-Pp) * Vp/
        Pf*1,OOO **Where: V = volume of phosphorus fertilizer needed Pp = phosphorus concentration, measured in pond (ug/L) Vp = volume of fish pond (m3) Pf = phosphorus concentration of fertilizer (g/L)** ****2. To determine  nitrogen added by phosphorus fertilizer:**** Na = (30-Pp) * Nf/Pf **Where: Na = Nitrogen added by phosphorus fertilizer (ug/L) Pp = phosphorus concentration, measured in pond (ug/L) Nf = nitrogen concentration of phosphorus fertilizer (g/L) Pf = phosphorus concentration of fertilizer (g/L)** ****3. To determine  nitrogen amounts (assuming no phosphorus contamination):**** V = (600-Np-Na) * VpNf*1,OOO **Where: V= volume of nitrogen fertilizer needed Np = nitrogen concentration (NO3+NH4), measured in  pond (ug/L) Na = nitrogen added to pond by phosphorus fertilizer Vp = volume of fish pond (m3) Nf = nitrogen concentration of fertilizer (ammonia, nitrate, and urea)** Total Phosphorus  ****For the following equations use these  conversions: Converting between total phosphorus (P) and  phosphate (PO4)**Use the Atomic mass of  the formulas to create a ratio, as follows:** Atomic weight of P  (Phosphorus) = 31
        Atomic weight of O (Oxygen) = 16 **Atomic weight of P         =   (1*31)Atomic weight of PO4   ((1*31)  * (16*4))= 31 / 95= 0.3** **You can now use this ratio to convert between P and PO4. If you  measure the phosphate in your pond, divide the value by 3 and it will give you the amount  of total phosphorus. If you measure total phosphorus, multiply by 3 to get the phosphate.**Converting between %P2O5 and %P**** **Use the following  equations:** **P2O5 atomic weight = P*2 + O*5 = (31*2) + (16*5)
      = 142 %P    =   P2/P2O5
        = (2*31) / 142
        = 62 / 142
      = 0.44** **Therefore, to get the %P from a fertilizer package, multiply the package P  value (%P2O5) by 0.44.** ****Converting between %N and %NO3 (nitrate)**** **Use the following  equations:** **N (nitrogen) atomic weight = 14
      O (oxygen) atomic weight =16 NO3 atomic weight = 1*N + 3*O
        = 14 + (3*16)
      = 62 %NO3 = 62 / 14 = 4.4** **Therefore, to get the %NO3 from a fertilizer package, multiply  the N value by 4.4.** **Click here to download a high resolution picture of the image shown below.** Calculations to Use Aquatic 
      Animal Drug Approval Partnership Program ~ AADAP Updates **Hydrogen Peroxide Removed from FDA's LRP 
          Drug List
          The Food and Drug Administration (FDA) announced recently (2 May 2007) 
          the removal of hydrogen peroxide from the list of Low Regulatory 
          Priority Aquaculture Drugs identified in the Program 
              Policy and Procedures Manual Guide 1240.4200.  As a 
            consequence, the only approved hydrogen peroxide product available is 
            Eka Chemicals 35% Perox-Aid, and its use is limited to only those 
            indications on the approved product label. For more information, refer 
            to CVMs Update dated 2 May 2007. Calcein Updates
        More pilot immersion marking studies completed:**
      SE-MARK treatment of pallid sturgeon.
              SE-MARK treatment of pallid sturgeon.
      **AADAP has 
        been conducting a few "quick and clean" studies to get some sense of 
        the breadth (species- and life stage-wise) of SE-MARKs 
        effectiveness. In two separate study sets, weve evaluated SE-MARK 
        treatment of channel catfish fingerlings and pallid sturgeon fry. In 
        the case of the former, 2-3" fingerlings marked exceptionally well 
        with or without a pre-treatment salt bath (see picturesabove). 
        However, treatment of 2 to 5-day old pallid sturgeon fry with SE-MARK 
        (without a pre-treatment salt bath) failed to produce an easily 
        detectable mark. A pre-treatment salt bath was not tested as it was 
        felt that it would be much too stressful on this very early 
        life-stage. As opportunities present themselves, AADAP will continue 
        to test other species and life-stages for their "markability."**
      **** **Return
              to MTAN selection pageReturn to Ashland NFWCO home pageReturn to Region 3 U.S. Fish and Wildlife Service**  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.
 Last updated:
      January 2, 2009
    
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