Water Quality and Water Quality and AquacultureAquaculture

Choose 2 Bodies of waterChoose 2 Bodies of water

One that you think has poor water One that you think has poor water qualityquality

One that you think has excellent One that you think has excellent water qualitywater quality

Why did you choose themWhy did you choose them

What Factors are What Factors are ImportantImportant

Dissolved OxygenDissolved Oxygen Temperature and StratificationTemperature and Stratification pHpH AlkalinityAlkalinity HardnessHardness Nitrogen CompoundsNitrogen Compounds SalinitySalinity Carbon DioxideCarbon Dioxide TurbidityTurbidity

Dissolved OxygenDissolved Oxygen

Why is it import?Why is it import?– Fish respirationFish respiration– Bacteria respirationBacteria respiration

Generally the first limiting factor in Generally the first limiting factor in aquaculture productionaquaculture production

What % of the air is Oxygen?What % of the air is Oxygen? What % of the water?What % of the water?

Where Does the Oxygen in Where Does the Oxygen in the Water Come From?the Water Come From?

90% comes from photosynthesis90% comes from photosynthesis

6CO6CO22 + 6H + 6H22O + energy = CO + energy = C66HH1212OO66 +6O +6O22

10% comes from the air water interface10% comes from the air water interface

DiffusionDiffusion– movement from an area of high concentration to movement from an area of high concentration to

an area of low concentrationan area of low concentration

Where Does the Oxygen Where Does the Oxygen Go?Go?

RespirationRespiration OxidationOxidation

CC66HH1212OO66 +6O +6O22 --> 6CO --> 6CO22 + 6H + 6H22O + energyO + energy

Sugar + Oxygen = Carbondioxide + water Sugar + Oxygen = Carbondioxide + water + + energy energy

How do different levels of How do different levels of DO effect aquaculture DO effect aquaculture

organisms?organisms?

How does temperature How does temperature affect the amount of DO?affect the amount of DO?

How does temperature How does temperature affect the amount of DO?affect the amount of DO?

How does temperature How does temperature affect the amount of DO?affect the amount of DO?

Can the water have too Can the water have too much dissolved oxygen?much dissolved oxygen?

Yes, it’s called supersaturationYes, it’s called supersaturation– this means that at times the water this means that at times the water

may contain more than it can may contain more than it can physically hold.physically hold.

– Caused by oxygen being added faster Caused by oxygen being added faster than it can be released from the pondthan it can be released from the pond

– can actually poison fish and other can actually poison fish and other animals in the pondanimals in the pond

When might When might supersaturation occur?supersaturation occur?

When a pond has a dense algae When a pond has a dense algae bloom and there is hot sunny bloom and there is hot sunny weather.weather.

At the base of a waterfall.At the base of a waterfall.

How does the oxygen get How does the oxygen get depleted?depleted?

Excessive oxygen demandExcessive oxygen demand Net loss of oxygenNet loss of oxygen Algal bloom die-offAlgal bloom die-off Turn overTurn over

Carbon Dioxide & Oxygen Carbon Dioxide & Oxygen BudgetBudget

Oxygen Gains and LossesOxygen Gains and Losses

Photosynthesis by Photosynthesis by phytoplanktonphytoplankton

DiffusionDiffusion

Plankton respirationPlankton respiration Fish respirationFish respiration Respiration by Respiration by

organisms in the mudorganisms in the mud DiffusionDiffusion

5 to 20 ppm5 to 20 ppm

1 to 5 ppm1 to 5 ppm

5 to 15 ppm5 to 15 ppm 2 to 6 ppm2 to 6 ppm 1 to 3 ppm1 to 3 ppm

1 to 5 ppm1 to 5 ppm

GainsGains

Losse

s

Losse

s

Example budgetExample budget

Day 1Day 1– am DO of 6 ppmam DO of 6 ppm

bloom adds 10 ppmbloom adds 10 ppm windy, diffusion adds 10 windy, diffusion adds 10

ppmppm Respiration by plants and Respiration by plants and

animals in the mud 9ppmanimals in the mud 9ppm Fish respiration 3ppmFish respiration 3ppm Diffusion out of pond 2 ppmDiffusion out of pond 2 ppm

6ppm6ppm +10 ppm+10 ppm +10 ppm+10 ppm = 26 ppm= 26 ppm - 9 ppm- 9 ppm - 3 ppm- 3 ppm - 2 ppm- 2 ppm = 7 ppm= 7 ppm

Example budget - Day 2Example budget - Day 2 7 ppm to start7 ppm to start + 10 ppm photosynthesis + 10 ppm photosynthesis + 1 ppm diffusion - calm day+ 1 ppm diffusion - calm day = 18 ppm available= 18 ppm available - 9 ppm respiration of phytoplankton - 9 ppm respiration of phytoplankton

and organisms in the mudand organisms in the mud - 3 ppm fish respiration- 3 ppm fish respiration - 2 ppm diffusion- 2 ppm diffusion 4 ppm left on the morning of day 34 ppm left on the morning of day 3

What would happen if the What would happen if the weather stayed the same?weather stayed the same?

In most cases, a system’s ability to add dissolved oxygen to water will become the first limiting factor in a system’s fish carrying capacity.

How will the density of the How will the density of the algae bloom affect the algae bloom affect the

DO?DO?

How will the density of the How will the density of the algae bloom affect the algae bloom affect the

DO?DO?

How will the density of the How will the density of the algae bloom affect the algae bloom affect the

DO?DO?

How will the density of the How will the density of the algae bloom affect the algae bloom affect the

DO?DO?

Depth vs OxygenDepth vs Oxygen

Depth vs OxygenDepth vs Oxygen

Depth vs OxygenDepth vs Oxygen

Depth vs OxygenDepth vs Oxygen

Stay in the ZoneStay in the Zone

The most productive zone in lakes, The most productive zone in lakes, oceans and other bodies of water is oceans and other bodies of water is called thecalled the

This zone ends at the point where there This zone ends at the point where there is less than 1% of the incident light.is less than 1% of the incident light.