Water Quality and DiseaseWater Quality and Disease

Dr. Craig KasperDr. Craig KasperAquaculture Disease Processes Aquaculture Disease Processes

FAS 2253CFAS 2253C

Aquatic EnvironmentAquatic Environment• Water quality and quantity is one of the most Water quality and quantity is one of the most

important factors to maintain fish health. important factors to maintain fish health.

• Inadequate water quality causes more losses than Inadequate water quality causes more losses than any other problem!any other problem!

• Factors that influence water quality/quantity:Factors that influence water quality/quantity:– Feed ratesFeed rates– Feed typesFeed types– Flow ratesFlow rates– Tanks/containers (flow dynamics)Tanks/containers (flow dynamics)– TemperatureTemperature

Water QualityWater Quality• Daily or weekly testsDaily or weekly tests • Semi-annually or Semi-annually or

annuallyannually

Daily or Weekly Daily or Weekly

• Dissolved oxygenDissolved oxygen• Nitrogen compoundsNitrogen compounds

– ammoniaammonia– nitritenitrite– nitratesnitrates

• pHpH• AlkalinityAlkalinity• HardnessHardness

• Carbon DioxideCarbon Dioxide• TemperatureTemperature• Hydrogen sulfideHydrogen sulfide• Total suspended Total suspended

solidssolids• ChlorineChlorine

Dissolved OxygenDissolved Oxygen• ImportanceImportance

– highest cause of mortalityhighest cause of mortality• SolubilitySolubility

– variablesvariables

•

• Safe levelsSafe levels

Dissolved OxygenDissolved Oxygen• Uptake influenced by condition of gillsUptake influenced by condition of gills

– healthy gills, uptake easyhealthy gills, uptake easy– damaged, oxygen uptake impaireddamaged, oxygen uptake impaired

•

Oxygen RequirementsOxygen Requirements

• Dependent on temperatureDependent on temperature• Dependent on demands of organismsDependent on demands of organisms

baseline baseline 0022 measure measure– sessilesessile normalnormal– feedingfeeding elevatedelevated– activeactive elevatedelevated– stressed?stressed? elevatedelevated– COCO22 elevated elevated depresseddepressed

Nitrogen CompoundsNitrogen Compounds

• TypesTypes– dissolved gasdissolved gas– ammoniaammonia

• ionizedionized• un-ionizedun-ionized

– nitritenitrite– nitratenitrate

AmmoniaAmmonia

• Ammonia Ammonia – NHNH33, NH, NH44

++

• Two forms Two forms – unionized NHunionized NH33

– ionized (NHionized (NH44++))

• pH a concern when dealing with exposurepH a concern when dealing with exposure• Chronic exposure (un-ionized form) Chronic exposure (un-ionized form)

Nitrogen Equillibria: Nitrogen Equillibria: NHNH33/NH/NH44++

• ammonia (NH3) is toxic to fish/inverts

• pH affects proportion of NH3/NH4

+ • as pH increases, NH3

increases• calculation example TAN

= 1.5 mg/L, 26oC, pH = 8.6

• answer: 0.30 mg NH3/L Affect of pH/temp on NH3/NH4+

equillibria (next slide)

Affect of pH/temp on NH3/NH4+

equillibria

Nitrogen Equillibria: Nitrogen Equillibria: NHNH33/NH/NH44++

• ammonia (NH3) is toxic to fish/inverts

• pH affects proportion of NH3/NH4

+ • as pH increases, NH3

increases• calculation example TAN

= 1.5 mg/L, 26oC, pH = 8.6

• answer: 0.35 mg NH3/L

Ammonia Prob.: How do I fix it?Ammonia Prob.: How do I fix it?

• Lower pH below 7.0 (why?)Lower pH below 7.0 (why?)

-25 - 50% water change -25 - 50% water change

-Use chemical to neutralize ammonia (zeolite)-Use chemical to neutralize ammonia (zeolite)

-Discontinue or reduce feeding -Discontinue or reduce feeding

-NH-NH3 3 >1 ppm treat immediately!>1 ppm treat immediately!

Ammonia ToxicityAmmonia Toxicity

Species 96- hour LC50 (mg/L NH3) Pink salmon 0.08- 0.1 Brown trout 0.50- 0.70 Rainbow trout 0.16- 1.10 Largemouth bass 0.9- 1.4 Common carp 2.2 Channel catfish 0.50- 3.8 Shrimp 5.71

NitriteNitrite• Nitrite (NONitrite (NO22

--) ) – Secondary product of nitrificationSecondary product of nitrification

• Nitrite levels greater than 0.05 to 0.06 mg/L Nitrite levels greater than 0.05 to 0.06 mg/L can be toxic!can be toxic!

• • 10 times stronger than the toxic threshold for 10 times stronger than the toxic threshold for

un ionized ammoniaun ionized ammonia

• Decreasing pH increases the harmful effects.Decreasing pH increases the harmful effects.

NitriteNitrite• Brown blood disease Brown blood disease (p. 67 in Noga) (p. 67 in Noga)

(Methemoglobinemia)-“new-tank” syndrome (Methemoglobinemia)-“new-tank” syndrome – Blood appears dark in color Blood appears dark in color

• Due to excessive presence of methemoglobinDue to excessive presence of methemoglobin• Treatment Treatment

– Flushing with fresh waterFlushing with fresh water– Add nitrifying bacteriaAdd nitrifying bacteria– Salt! Recommend 10:1 ratioSalt! Recommend 10:1 ratio

• Hypertrophy and hyperplasia in the gill Hypertrophy and hyperplasia in the gill lamellaelamellae

• Lesions/hemorrhaging in thymusLesions/hemorrhaging in thymus

Nitrite (NONitrite (NO33--) Toxicity) Toxicity

Species 48- or 96- hr LC50 (mg/L NO2- N) Rainbow trout 0.19- 0.39 Chinook salmon 0.88 Common carp 2.6 Channel catfish 7.1- 13 Largemouth bass 140 Guadeloupe bass 160 Shrimp, freshwater 8.5- 15.4 Shrimp, saltwater 45- 204 mg/L

NitrateNitrate• Nitrate (NONitrate (NO33

--) is the final breakdown ) is the final breakdown product in the oxidation of ammonia product in the oxidation of ammonia

• Not as toxic to aquaticsNot as toxic to aquatics

• Similar symptoms to nitrite toxicity, Similar symptoms to nitrite toxicity, but values must be much higher.but values must be much higher.

Nitrate ToxicityNitrate Toxicity

Species 96- hr LC50 (mg/L NO3- N) Guppy 180- 200 Guadeloupe bass 1,260 Chinook salmon 1,310 Rainbow trout 1,360 Channel catfish 1,400 Bluegill 420- 2,000 Shrimp Who knows???

Nitrification: Good or bad?Nitrification: Good or bad?

NONO33-- NHNH33

1½ O1½ O22

nitrosomonas nitrosomonas nitrobacter nitrobacter

1½ O1½ O22 NONO22--

• Requires 3 moles oxygen to convert one mole of ammonia to nitrateRequires 3 moles oxygen to convert one mole of ammonia to nitrate

• Nitrification is an acidifying reactionNitrification is an acidifying reaction

RelationshipsRelationships

pHpH• Measure of the hydrogen Measure of the hydrogen

ion concentrationion concentration

• 1-14 scale1-14 scale– less than 7 acidicless than 7 acidic– greater than 7 basicgreater than 7 basic

• Safe rangeSafe range– 6.5-96.5-9

Carbon Dioxide (COCarbon Dioxide (CO22))

• SourcesSources– SurfaceSurface– WellsWells

• carboniferous rockcarboniferous rock

• RemovalRemoval– degassingdegassing– buffersbuffers

• calcium carbonatecalcium carbonate• sodium bicarbonatesodium bicarbonate

CHCH22O (food) + OO (food) + O22 COCO22 + H + H22OO

AlkalinityAlkalinity• Alkalinity is the capacity of water to Alkalinity is the capacity of water to bufferbuffer

against wide pH changes.against wide pH changes.• Acceptable range 20-300 mg/L Acceptable range 20-300 mg/L

CaCOCaCO33 + CO + CO22 + H + H22O O Ca Ca+2+2 + 2HCO + 2HCO33--

Bicarbonate:Bicarbonate: CO CO22 + H + H22O O H H++ + HCO + HCO33--

Carbonate:Carbonate: HCO HCO33-- H H++ + CO + CO33

--

Effects of Effects of calcitecalcite lime: lime:

**Dolomite Dolomite CaMg(COCaMg(CO33))2 2 yields 4HCOyields 4HCO33--

HardnessHardness• Hardness is the measure of divalent cationsHardness is the measure of divalent cations

– Ca 2+, Mg 2+, Mn 2+Ca 2+, Mg 2+, Mn 2+– Calcium is used for bone and exoskeleton Calcium is used for bone and exoskeleton

formation and absorbed across gillsformation and absorbed across gills– Soft water = molt problems, bone deformitiesSoft water = molt problems, bone deformities– Suggest > 50 ppmSuggest > 50 ppm

• Hardness is used as an indicator of alkalinity Hardness is used as an indicator of alkalinity but hardness is but hardness is notnot a measure of alkalinity a measure of alkalinity– Magnesium or calcium sulfate increases hardness Magnesium or calcium sulfate increases hardness

but has no affect on alkalinitybut has no affect on alkalinity

Hydrogen Sulfide (p. 225-226, Hydrogen Sulfide (p. 225-226, Noga)Noga)

• SourceSource– Well waterWell water– Ponds Ponds

• Anerobic conditions of Anerobic conditions of benthosbenthos

– Under net-pensUnder net-pens• Extremely toxic to fishExtremely toxic to fish• RemovalRemoval

– AerationAeration– Raise pHRaise pH– Lower temp.Lower temp.– Add Potassium Permanganate Add Potassium Permanganate

(freshwater only!)(freshwater only!)

Total SolidsTotal Solids• TypesTypes

– suspendedsuspended– settleablesettleable

• SourcesSources– runoffrunoff– uneaten fooduneaten food– fecesfeces

• Safe levelsSafe levels– less than 1,000 mg/Lless than 1,000 mg/L

• RemovalRemoval– filtrationfiltration– settling chamberssettling chambers

Suspended SolidsSuspended Solids

• Potential problemsPotential problems– Light?Light?– Turbidity?Turbidity?– Gills?Gills?

• Reduce oxygen transportReduce oxygen transport• 80 - 100 ppm TSS reasonable for 80 - 100 ppm TSS reasonable for

salmonidssalmonids

ChlorineChlorine• DisinfectantDisinfectant

– ClCl2 2 (Chlorine gas choramine-T)(Chlorine gas choramine-T)– HClO (hypochlorous ion) (bleach)HClO (hypochlorous ion) (bleach)

• Safe levelsSafe levels– less than 0.03 mg/Lless than 0.03 mg/L

• RemovalRemoval– AerationAeration– Chemical (Sodium Thiosulfate, 200 mg/L available Chemical (Sodium Thiosulfate, 200 mg/L available

chlorine is neutralized by 1.5 g sodium thiosulfate)chlorine is neutralized by 1.5 g sodium thiosulfate)– SunlightSunlight

• Chlorine reacts with water to form strong acid Chlorine reacts with water to form strong acid

Chlorine toxicityChlorine toxicity

• Acid is more toxic than hypochlorite ionAcid is more toxic than hypochlorite ion• Destroys epidermal surfaces = gills Destroys epidermal surfaces = gills • Toxicity depends on temp, DO, free chlorine Toxicity depends on temp, DO, free chlorine

present, presence other pollutantspresent, presence other pollutants• Residual chlorine (free plus chloramine)Residual chlorine (free plus chloramine)

0.2 - 0.3 ppm kills fish rapidly (ornamentals 0.2 - 0.3 ppm kills fish rapidly (ornamentals 0.09 ppm!!)0.09 ppm!!)

• Chlorine and nitrogenous organics = Chlorine and nitrogenous organics = chloramines that are very toxicchloramines that are very toxic

TemperatureTemperature• EffectsEffects

– Alters metabolismAlters metabolism– Effects pathogensEffects pathogens– Changes gas solubility Changes gas solubility

• Fish CategoriesFish Categories– warmwaterwarmwater– coolwatercoolwater– coldwatercoldwater

Heavy Metal ContaminantsHeavy Metal Contaminants

• Heavy metals - Cd, Cu, Zn, Hg, must be all < .1 mg/L.Heavy metals - Cd, Cu, Zn, Hg, must be all < .1 mg/L.

• Old plumbing systems are problematic (CuOld plumbing systems are problematic (Cu2+2+, Zn alloys) , Zn alloys)

• Soft water makes a difference in toxicity of metals Soft water makes a difference in toxicity of metals (increases uptake)(increases uptake)

• Most can be removed by using activated carbon filters!Most can be removed by using activated carbon filters!

Dissolved GassesDissolved Gasses• Problem gassesProblem gasses

– Oxgen?Oxgen?• maintain less than 110%maintain less than 110%

• Problem sources Problem sources – WellsWells– Leaky pipesLeaky pipes– Solved by using degassingSolved by using degassing columnscolumns

leaky pipeleaky pipe

Popeye/exophthalmiaPopeye/exophthalmia

dorsal viewdorsal view

Characteristics of gas bubble Characteristics of gas bubble diseasedisease

• Bubbles under skin (crackles…just like diving)Bubbles under skin (crackles…just like diving)– and other soft tissues…fins, tail, mouthand other soft tissues…fins, tail, mouth

• Gas emboli in vascular system = deathGas emboli in vascular system = death

• Similar to bends or decompression sicknessSimilar to bends or decompression sickness

Spill vs. no spill management of Spill vs. no spill management of Columbia RiverColumbia River

• History - Excess water removed used to be a big History - Excess water removed used to be a big problem.problem.

• Rough guidelines for negative responseRough guidelines for negative responseClean Water Act says 110% is standardClean Water Act says 110% is standardwhat difference between 110 and 120%?what difference between 110 and 120%?

• Lethal Leves for salmonids Lethal Leves for salmonids – 103 – 104% = yolk sac and fingerlings103 – 104% = yolk sac and fingerlings– 105- 113 % = older fingerlings and yearlings105- 113 % = older fingerlings and yearlings– 118 % = adults118 % = adults

Columbia RiverColumbia River• In 1960s in Columbia River,In 1960s in Columbia River,

– Adults Adults • Exophthalmia Exophthalmia • bubbles in skin and mouth bubbles in skin and mouth • hemorrhaged eyes later cause blindness - hemorrhaged eyes later cause blindness -

impair spawningimpair spawning

• External symptoms disappear rapidly External symptoms disappear rapidly after deathafter death

• Changed water use and flip lipsChanged water use and flip lips• 1990s high spill head burns in salmon 1990s high spill head burns in salmon

Does Compensation Occur?Does Compensation Occur?• One meter depth = about 10% reduction in gas One meter depth = about 10% reduction in gas

saturation.saturation.

• Late 1970s fish were deeper than 1.5 m in 110% Late 1970s fish were deeper than 1.5 m in 110% saturation.saturation.

• Fish were using shallower water in normal Fish were using shallower water in normal saturation.saturation.

• Fish ladders require fish to come to surface or Fish ladders require fish to come to surface or near surface.near surface.

Questions/uncertaintyQuestions/uncertainty

• Behavioral Compensation? Does it occur? Behavioral Compensation? Does it occur? • Migration pathways for Adult salmonMigration pathways for Adult salmon• Migration pathways for juvenile salmonMigration pathways for juvenile salmon• How good are flip lips?How good are flip lips?• Voluntary vs non-voluntary spill issues?Voluntary vs non-voluntary spill issues?• Immediate vs delayed mortality?Immediate vs delayed mortality?• Predisposition to other invasions?Predisposition to other invasions?